| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2018 Facebook */ |
| |
| #include <uapi/linux/btf.h> |
| #include <uapi/linux/bpf.h> |
| #include <uapi/linux/bpf_perf_event.h> |
| #include <uapi/linux/types.h> |
| #include <linux/seq_file.h> |
| #include <linux/compiler.h> |
| #include <linux/ctype.h> |
| #include <linux/errno.h> |
| #include <linux/slab.h> |
| #include <linux/anon_inodes.h> |
| #include <linux/file.h> |
| #include <linux/uaccess.h> |
| #include <linux/kernel.h> |
| #include <linux/idr.h> |
| #include <linux/sort.h> |
| #include <linux/bpf_verifier.h> |
| #include <linux/btf.h> |
| #include <linux/btf_ids.h> |
| #include <linux/bpf.h> |
| #include <linux/bpf_lsm.h> |
| #include <linux/skmsg.h> |
| #include <linux/perf_event.h> |
| #include <linux/bsearch.h> |
| #include <linux/kobject.h> |
| #include <linux/sysfs.h> |
| |
| #include <net/netfilter/nf_bpf_link.h> |
| |
| #include <net/sock.h> |
| #include <net/xdp.h> |
| #include "../tools/lib/bpf/relo_core.h" |
| |
| /* BTF (BPF Type Format) is the meta data format which describes |
| * the data types of BPF program/map. Hence, it basically focus |
| * on the C programming language which the modern BPF is primary |
| * using. |
| * |
| * ELF Section: |
| * ~~~~~~~~~~~ |
| * The BTF data is stored under the ".BTF" ELF section |
| * |
| * struct btf_type: |
| * ~~~~~~~~~~~~~~~ |
| * Each 'struct btf_type' object describes a C data type. |
| * Depending on the type it is describing, a 'struct btf_type' |
| * object may be followed by more data. F.e. |
| * To describe an array, 'struct btf_type' is followed by |
| * 'struct btf_array'. |
| * |
| * 'struct btf_type' and any extra data following it are |
| * 4 bytes aligned. |
| * |
| * Type section: |
| * ~~~~~~~~~~~~~ |
| * The BTF type section contains a list of 'struct btf_type' objects. |
| * Each one describes a C type. Recall from the above section |
| * that a 'struct btf_type' object could be immediately followed by extra |
| * data in order to describe some particular C types. |
| * |
| * type_id: |
| * ~~~~~~~ |
| * Each btf_type object is identified by a type_id. The type_id |
| * is implicitly implied by the location of the btf_type object in |
| * the BTF type section. The first one has type_id 1. The second |
| * one has type_id 2...etc. Hence, an earlier btf_type has |
| * a smaller type_id. |
| * |
| * A btf_type object may refer to another btf_type object by using |
| * type_id (i.e. the "type" in the "struct btf_type"). |
| * |
| * NOTE that we cannot assume any reference-order. |
| * A btf_type object can refer to an earlier btf_type object |
| * but it can also refer to a later btf_type object. |
| * |
| * For example, to describe "const void *". A btf_type |
| * object describing "const" may refer to another btf_type |
| * object describing "void *". This type-reference is done |
| * by specifying type_id: |
| * |
| * [1] CONST (anon) type_id=2 |
| * [2] PTR (anon) type_id=0 |
| * |
| * The above is the btf_verifier debug log: |
| * - Each line started with "[?]" is a btf_type object |
| * - [?] is the type_id of the btf_type object. |
| * - CONST/PTR is the BTF_KIND_XXX |
| * - "(anon)" is the name of the type. It just |
| * happens that CONST and PTR has no name. |
| * - type_id=XXX is the 'u32 type' in btf_type |
| * |
| * NOTE: "void" has type_id 0 |
| * |
| * String section: |
| * ~~~~~~~~~~~~~~ |
| * The BTF string section contains the names used by the type section. |
| * Each string is referred by an "offset" from the beginning of the |
| * string section. |
| * |
| * Each string is '\0' terminated. |
| * |
| * The first character in the string section must be '\0' |
| * which is used to mean 'anonymous'. Some btf_type may not |
| * have a name. |
| */ |
| |
| /* BTF verification: |
| * |
| * To verify BTF data, two passes are needed. |
| * |
| * Pass #1 |
| * ~~~~~~~ |
| * The first pass is to collect all btf_type objects to |
| * an array: "btf->types". |
| * |
| * Depending on the C type that a btf_type is describing, |
| * a btf_type may be followed by extra data. We don't know |
| * how many btf_type is there, and more importantly we don't |
| * know where each btf_type is located in the type section. |
| * |
| * Without knowing the location of each type_id, most verifications |
| * cannot be done. e.g. an earlier btf_type may refer to a later |
| * btf_type (recall the "const void *" above), so we cannot |
| * check this type-reference in the first pass. |
| * |
| * In the first pass, it still does some verifications (e.g. |
| * checking the name is a valid offset to the string section). |
| * |
| * Pass #2 |
| * ~~~~~~~ |
| * The main focus is to resolve a btf_type that is referring |
| * to another type. |
| * |
| * We have to ensure the referring type: |
| * 1) does exist in the BTF (i.e. in btf->types[]) |
| * 2) does not cause a loop: |
| * struct A { |
| * struct B b; |
| * }; |
| * |
| * struct B { |
| * struct A a; |
| * }; |
| * |
| * btf_type_needs_resolve() decides if a btf_type needs |
| * to be resolved. |
| * |
| * The needs_resolve type implements the "resolve()" ops which |
| * essentially does a DFS and detects backedge. |
| * |
| * During resolve (or DFS), different C types have different |
| * "RESOLVED" conditions. |
| * |
| * When resolving a BTF_KIND_STRUCT, we need to resolve all its |
| * members because a member is always referring to another |
| * type. A struct's member can be treated as "RESOLVED" if |
| * it is referring to a BTF_KIND_PTR. Otherwise, the |
| * following valid C struct would be rejected: |
| * |
| * struct A { |
| * int m; |
| * struct A *a; |
| * }; |
| * |
| * When resolving a BTF_KIND_PTR, it needs to keep resolving if |
| * it is referring to another BTF_KIND_PTR. Otherwise, we cannot |
| * detect a pointer loop, e.g.: |
| * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + |
| * ^ | |
| * +-----------------------------------------+ |
| * |
| */ |
| |
| #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) |
| #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) |
| #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) |
| #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) |
| #define BITS_ROUNDUP_BYTES(bits) \ |
| (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) |
| |
| #define BTF_INFO_MASK 0x9f00ffff |
| #define BTF_INT_MASK 0x0fffffff |
| #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) |
| #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) |
| |
| /* 16MB for 64k structs and each has 16 members and |
| * a few MB spaces for the string section. |
| * The hard limit is S32_MAX. |
| */ |
| #define BTF_MAX_SIZE (16 * 1024 * 1024) |
| |
| #define for_each_member_from(i, from, struct_type, member) \ |
| for (i = from, member = btf_type_member(struct_type) + from; \ |
| i < btf_type_vlen(struct_type); \ |
| i++, member++) |
| |
| #define for_each_vsi_from(i, from, struct_type, member) \ |
| for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ |
| i < btf_type_vlen(struct_type); \ |
| i++, member++) |
| |
| DEFINE_IDR(btf_idr); |
| DEFINE_SPINLOCK(btf_idr_lock); |
| |
| enum btf_kfunc_hook { |
| BTF_KFUNC_HOOK_COMMON, |
| BTF_KFUNC_HOOK_XDP, |
| BTF_KFUNC_HOOK_TC, |
| BTF_KFUNC_HOOK_STRUCT_OPS, |
| BTF_KFUNC_HOOK_TRACING, |
| BTF_KFUNC_HOOK_SYSCALL, |
| BTF_KFUNC_HOOK_FMODRET, |
| BTF_KFUNC_HOOK_CGROUP, |
| BTF_KFUNC_HOOK_SCHED_ACT, |
| BTF_KFUNC_HOOK_SK_SKB, |
| BTF_KFUNC_HOOK_SOCKET_FILTER, |
| BTF_KFUNC_HOOK_LWT, |
| BTF_KFUNC_HOOK_NETFILTER, |
| BTF_KFUNC_HOOK_KPROBE, |
| BTF_KFUNC_HOOK_MAX, |
| }; |
| |
| enum { |
| BTF_KFUNC_SET_MAX_CNT = 256, |
| BTF_DTOR_KFUNC_MAX_CNT = 256, |
| BTF_KFUNC_FILTER_MAX_CNT = 16, |
| }; |
| |
| struct btf_kfunc_hook_filter { |
| btf_kfunc_filter_t filters[BTF_KFUNC_FILTER_MAX_CNT]; |
| u32 nr_filters; |
| }; |
| |
| struct btf_kfunc_set_tab { |
| struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX]; |
| struct btf_kfunc_hook_filter hook_filters[BTF_KFUNC_HOOK_MAX]; |
| }; |
| |
| struct btf_id_dtor_kfunc_tab { |
| u32 cnt; |
| struct btf_id_dtor_kfunc dtors[]; |
| }; |
| |
| struct btf_struct_ops_tab { |
| u32 cnt; |
| u32 capacity; |
| struct bpf_struct_ops_desc ops[]; |
| }; |
| |
| struct btf { |
| void *data; |
| struct btf_type **types; |
| u32 *resolved_ids; |
| u32 *resolved_sizes; |
| const char *strings; |
| void *nohdr_data; |
| struct btf_header hdr; |
| u32 nr_types; /* includes VOID for base BTF */ |
| u32 types_size; |
| u32 data_size; |
| refcount_t refcnt; |
| u32 id; |
| struct rcu_head rcu; |
| struct btf_kfunc_set_tab *kfunc_set_tab; |
| struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab; |
| struct btf_struct_metas *struct_meta_tab; |
| struct btf_struct_ops_tab *struct_ops_tab; |
| |
| /* split BTF support */ |
| struct btf *base_btf; |
| u32 start_id; /* first type ID in this BTF (0 for base BTF) */ |
| u32 start_str_off; /* first string offset (0 for base BTF) */ |
| char name[MODULE_NAME_LEN]; |
| bool kernel_btf; |
| __u32 *base_id_map; /* map from distilled base BTF -> vmlinux BTF ids */ |
| }; |
| |
| enum verifier_phase { |
| CHECK_META, |
| CHECK_TYPE, |
| }; |
| |
| struct resolve_vertex { |
| const struct btf_type *t; |
| u32 type_id; |
| u16 next_member; |
| }; |
| |
| enum visit_state { |
| NOT_VISITED, |
| VISITED, |
| RESOLVED, |
| }; |
| |
| enum resolve_mode { |
| RESOLVE_TBD, /* To Be Determined */ |
| RESOLVE_PTR, /* Resolving for Pointer */ |
| RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union |
| * or array |
| */ |
| }; |
| |
| #define MAX_RESOLVE_DEPTH 32 |
| |
| struct btf_sec_info { |
| u32 off; |
| u32 len; |
| }; |
| |
| struct btf_verifier_env { |
| struct btf *btf; |
| u8 *visit_states; |
| struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; |
| struct bpf_verifier_log log; |
| u32 log_type_id; |
| u32 top_stack; |
| enum verifier_phase phase; |
| enum resolve_mode resolve_mode; |
| }; |
| |
| static const char * const btf_kind_str[NR_BTF_KINDS] = { |
| [BTF_KIND_UNKN] = "UNKNOWN", |
| [BTF_KIND_INT] = "INT", |
| [BTF_KIND_PTR] = "PTR", |
| [BTF_KIND_ARRAY] = "ARRAY", |
| [BTF_KIND_STRUCT] = "STRUCT", |
| [BTF_KIND_UNION] = "UNION", |
| [BTF_KIND_ENUM] = "ENUM", |
| [BTF_KIND_FWD] = "FWD", |
| [BTF_KIND_TYPEDEF] = "TYPEDEF", |
| [BTF_KIND_VOLATILE] = "VOLATILE", |
| [BTF_KIND_CONST] = "CONST", |
| [BTF_KIND_RESTRICT] = "RESTRICT", |
| [BTF_KIND_FUNC] = "FUNC", |
| [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", |
| [BTF_KIND_VAR] = "VAR", |
| [BTF_KIND_DATASEC] = "DATASEC", |
| [BTF_KIND_FLOAT] = "FLOAT", |
| [BTF_KIND_DECL_TAG] = "DECL_TAG", |
| [BTF_KIND_TYPE_TAG] = "TYPE_TAG", |
| [BTF_KIND_ENUM64] = "ENUM64", |
| }; |
| |
| const char *btf_type_str(const struct btf_type *t) |
| { |
| return btf_kind_str[BTF_INFO_KIND(t->info)]; |
| } |
| |
| /* Chunk size we use in safe copy of data to be shown. */ |
| #define BTF_SHOW_OBJ_SAFE_SIZE 32 |
| |
| /* |
| * This is the maximum size of a base type value (equivalent to a |
| * 128-bit int); if we are at the end of our safe buffer and have |
| * less than 16 bytes space we can't be assured of being able |
| * to copy the next type safely, so in such cases we will initiate |
| * a new copy. |
| */ |
| #define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16 |
| |
| /* Type name size */ |
| #define BTF_SHOW_NAME_SIZE 80 |
| |
| /* |
| * The suffix of a type that indicates it cannot alias another type when |
| * comparing BTF IDs for kfunc invocations. |
| */ |
| #define NOCAST_ALIAS_SUFFIX "___init" |
| |
| /* |
| * Common data to all BTF show operations. Private show functions can add |
| * their own data to a structure containing a struct btf_show and consult it |
| * in the show callback. See btf_type_show() below. |
| * |
| * One challenge with showing nested data is we want to skip 0-valued |
| * data, but in order to figure out whether a nested object is all zeros |
| * we need to walk through it. As a result, we need to make two passes |
| * when handling structs, unions and arrays; the first path simply looks |
| * for nonzero data, while the second actually does the display. The first |
| * pass is signalled by show->state.depth_check being set, and if we |
| * encounter a non-zero value we set show->state.depth_to_show to |
| * the depth at which we encountered it. When we have completed the |
| * first pass, we will know if anything needs to be displayed if |
| * depth_to_show > depth. See btf_[struct,array]_show() for the |
| * implementation of this. |
| * |
| * Another problem is we want to ensure the data for display is safe to |
| * access. To support this, the anonymous "struct {} obj" tracks the data |
| * object and our safe copy of it. We copy portions of the data needed |
| * to the object "copy" buffer, but because its size is limited to |
| * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we |
| * traverse larger objects for display. |
| * |
| * The various data type show functions all start with a call to |
| * btf_show_start_type() which returns a pointer to the safe copy |
| * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the |
| * raw data itself). btf_show_obj_safe() is responsible for |
| * using copy_from_kernel_nofault() to update the safe data if necessary |
| * as we traverse the object's data. skbuff-like semantics are |
| * used: |
| * |
| * - obj.head points to the start of the toplevel object for display |
| * - obj.size is the size of the toplevel object |
| * - obj.data points to the current point in the original data at |
| * which our safe data starts. obj.data will advance as we copy |
| * portions of the data. |
| * |
| * In most cases a single copy will suffice, but larger data structures |
| * such as "struct task_struct" will require many copies. The logic in |
| * btf_show_obj_safe() handles the logic that determines if a new |
| * copy_from_kernel_nofault() is needed. |
| */ |
| struct btf_show { |
| u64 flags; |
| void *target; /* target of show operation (seq file, buffer) */ |
| __printf(2, 0) void (*showfn)(struct btf_show *show, const char *fmt, va_list args); |
| const struct btf *btf; |
| /* below are used during iteration */ |
| struct { |
| u8 depth; |
| u8 depth_to_show; |
| u8 depth_check; |
| u8 array_member:1, |
| array_terminated:1; |
| u16 array_encoding; |
| u32 type_id; |
| int status; /* non-zero for error */ |
| const struct btf_type *type; |
| const struct btf_member *member; |
| char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */ |
| } state; |
| struct { |
| u32 size; |
| void *head; |
| void *data; |
| u8 safe[BTF_SHOW_OBJ_SAFE_SIZE]; |
| } obj; |
| }; |
| |
| struct btf_kind_operations { |
| s32 (*check_meta)(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left); |
| int (*resolve)(struct btf_verifier_env *env, |
| const struct resolve_vertex *v); |
| int (*check_member)(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type); |
| int (*check_kflag_member)(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type); |
| void (*log_details)(struct btf_verifier_env *env, |
| const struct btf_type *t); |
| void (*show)(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offsets, |
| struct btf_show *show); |
| }; |
| |
| static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; |
| static struct btf_type btf_void; |
| |
| static int btf_resolve(struct btf_verifier_env *env, |
| const struct btf_type *t, u32 type_id); |
| |
| static int btf_func_check(struct btf_verifier_env *env, |
| const struct btf_type *t); |
| |
| static bool btf_type_is_modifier(const struct btf_type *t) |
| { |
| /* Some of them is not strictly a C modifier |
| * but they are grouped into the same bucket |
| * for BTF concern: |
| * A type (t) that refers to another |
| * type through t->type AND its size cannot |
| * be determined without following the t->type. |
| * |
| * ptr does not fall into this bucket |
| * because its size is always sizeof(void *). |
| */ |
| switch (BTF_INFO_KIND(t->info)) { |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_CONST: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_TYPE_TAG: |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool btf_type_is_void(const struct btf_type *t) |
| { |
| return t == &btf_void; |
| } |
| |
| static bool btf_type_is_fwd(const struct btf_type *t) |
| { |
| return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; |
| } |
| |
| static bool btf_type_is_datasec(const struct btf_type *t) |
| { |
| return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; |
| } |
| |
| static bool btf_type_is_decl_tag(const struct btf_type *t) |
| { |
| return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG; |
| } |
| |
| static bool btf_type_nosize(const struct btf_type *t) |
| { |
| return btf_type_is_void(t) || btf_type_is_fwd(t) || |
| btf_type_is_func(t) || btf_type_is_func_proto(t) || |
| btf_type_is_decl_tag(t); |
| } |
| |
| static bool btf_type_nosize_or_null(const struct btf_type *t) |
| { |
| return !t || btf_type_nosize(t); |
| } |
| |
| static bool btf_type_is_decl_tag_target(const struct btf_type *t) |
| { |
| return btf_type_is_func(t) || btf_type_is_struct(t) || |
| btf_type_is_var(t) || btf_type_is_typedef(t); |
| } |
| |
| bool btf_is_vmlinux(const struct btf *btf) |
| { |
| return btf->kernel_btf && !btf->base_btf; |
| } |
| |
| u32 btf_nr_types(const struct btf *btf) |
| { |
| u32 total = 0; |
| |
| while (btf) { |
| total += btf->nr_types; |
| btf = btf->base_btf; |
| } |
| |
| return total; |
| } |
| |
| s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind) |
| { |
| const struct btf_type *t; |
| const char *tname; |
| u32 i, total; |
| |
| total = btf_nr_types(btf); |
| for (i = 1; i < total; i++) { |
| t = btf_type_by_id(btf, i); |
| if (BTF_INFO_KIND(t->info) != kind) |
| continue; |
| |
| tname = btf_name_by_offset(btf, t->name_off); |
| if (!strcmp(tname, name)) |
| return i; |
| } |
| |
| return -ENOENT; |
| } |
| |
| s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p) |
| { |
| struct btf *btf; |
| s32 ret; |
| int id; |
| |
| btf = bpf_get_btf_vmlinux(); |
| if (IS_ERR(btf)) |
| return PTR_ERR(btf); |
| if (!btf) |
| return -EINVAL; |
| |
| ret = btf_find_by_name_kind(btf, name, kind); |
| /* ret is never zero, since btf_find_by_name_kind returns |
| * positive btf_id or negative error. |
| */ |
| if (ret > 0) { |
| btf_get(btf); |
| *btf_p = btf; |
| return ret; |
| } |
| |
| /* If name is not found in vmlinux's BTF then search in module's BTFs */ |
| spin_lock_bh(&btf_idr_lock); |
| idr_for_each_entry(&btf_idr, btf, id) { |
| if (!btf_is_module(btf)) |
| continue; |
| /* linear search could be slow hence unlock/lock |
| * the IDR to avoiding holding it for too long |
| */ |
| btf_get(btf); |
| spin_unlock_bh(&btf_idr_lock); |
| ret = btf_find_by_name_kind(btf, name, kind); |
| if (ret > 0) { |
| *btf_p = btf; |
| return ret; |
| } |
| btf_put(btf); |
| spin_lock_bh(&btf_idr_lock); |
| } |
| spin_unlock_bh(&btf_idr_lock); |
| return ret; |
| } |
| |
| const struct btf_type *btf_type_skip_modifiers(const struct btf *btf, |
| u32 id, u32 *res_id) |
| { |
| const struct btf_type *t = btf_type_by_id(btf, id); |
| |
| while (btf_type_is_modifier(t)) { |
| id = t->type; |
| t = btf_type_by_id(btf, t->type); |
| } |
| |
| if (res_id) |
| *res_id = id; |
| |
| return t; |
| } |
| |
| const struct btf_type *btf_type_resolve_ptr(const struct btf *btf, |
| u32 id, u32 *res_id) |
| { |
| const struct btf_type *t; |
| |
| t = btf_type_skip_modifiers(btf, id, NULL); |
| if (!btf_type_is_ptr(t)) |
| return NULL; |
| |
| return btf_type_skip_modifiers(btf, t->type, res_id); |
| } |
| |
| const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf, |
| u32 id, u32 *res_id) |
| { |
| const struct btf_type *ptype; |
| |
| ptype = btf_type_resolve_ptr(btf, id, res_id); |
| if (ptype && btf_type_is_func_proto(ptype)) |
| return ptype; |
| |
| return NULL; |
| } |
| |
| /* Types that act only as a source, not sink or intermediate |
| * type when resolving. |
| */ |
| static bool btf_type_is_resolve_source_only(const struct btf_type *t) |
| { |
| return btf_type_is_var(t) || |
| btf_type_is_decl_tag(t) || |
| btf_type_is_datasec(t); |
| } |
| |
| /* What types need to be resolved? |
| * |
| * btf_type_is_modifier() is an obvious one. |
| * |
| * btf_type_is_struct() because its member refers to |
| * another type (through member->type). |
| * |
| * btf_type_is_var() because the variable refers to |
| * another type. btf_type_is_datasec() holds multiple |
| * btf_type_is_var() types that need resolving. |
| * |
| * btf_type_is_array() because its element (array->type) |
| * refers to another type. Array can be thought of a |
| * special case of struct while array just has the same |
| * member-type repeated by array->nelems of times. |
| */ |
| static bool btf_type_needs_resolve(const struct btf_type *t) |
| { |
| return btf_type_is_modifier(t) || |
| btf_type_is_ptr(t) || |
| btf_type_is_struct(t) || |
| btf_type_is_array(t) || |
| btf_type_is_var(t) || |
| btf_type_is_func(t) || |
| btf_type_is_decl_tag(t) || |
| btf_type_is_datasec(t); |
| } |
| |
| /* t->size can be used */ |
| static bool btf_type_has_size(const struct btf_type *t) |
| { |
| switch (BTF_INFO_KIND(t->info)) { |
| case BTF_KIND_INT: |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| case BTF_KIND_ENUM: |
| case BTF_KIND_DATASEC: |
| case BTF_KIND_FLOAT: |
| case BTF_KIND_ENUM64: |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static const char *btf_int_encoding_str(u8 encoding) |
| { |
| if (encoding == 0) |
| return "(none)"; |
| else if (encoding == BTF_INT_SIGNED) |
| return "SIGNED"; |
| else if (encoding == BTF_INT_CHAR) |
| return "CHAR"; |
| else if (encoding == BTF_INT_BOOL) |
| return "BOOL"; |
| else |
| return "UNKN"; |
| } |
| |
| static u32 btf_type_int(const struct btf_type *t) |
| { |
| return *(u32 *)(t + 1); |
| } |
| |
| static const struct btf_array *btf_type_array(const struct btf_type *t) |
| { |
| return (const struct btf_array *)(t + 1); |
| } |
| |
| static const struct btf_enum *btf_type_enum(const struct btf_type *t) |
| { |
| return (const struct btf_enum *)(t + 1); |
| } |
| |
| static const struct btf_var *btf_type_var(const struct btf_type *t) |
| { |
| return (const struct btf_var *)(t + 1); |
| } |
| |
| static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t) |
| { |
| return (const struct btf_decl_tag *)(t + 1); |
| } |
| |
| static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t) |
| { |
| return (const struct btf_enum64 *)(t + 1); |
| } |
| |
| static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) |
| { |
| return kind_ops[BTF_INFO_KIND(t->info)]; |
| } |
| |
| static bool btf_name_offset_valid(const struct btf *btf, u32 offset) |
| { |
| if (!BTF_STR_OFFSET_VALID(offset)) |
| return false; |
| |
| while (offset < btf->start_str_off) |
| btf = btf->base_btf; |
| |
| offset -= btf->start_str_off; |
| return offset < btf->hdr.str_len; |
| } |
| |
| static bool __btf_name_char_ok(char c, bool first) |
| { |
| if ((first ? !isalpha(c) : |
| !isalnum(c)) && |
| c != '_' && |
| c != '.') |
| return false; |
| return true; |
| } |
| |
| const char *btf_str_by_offset(const struct btf *btf, u32 offset) |
| { |
| while (offset < btf->start_str_off) |
| btf = btf->base_btf; |
| |
| offset -= btf->start_str_off; |
| if (offset < btf->hdr.str_len) |
| return &btf->strings[offset]; |
| |
| return NULL; |
| } |
| |
| static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) |
| { |
| /* offset must be valid */ |
| const char *src = btf_str_by_offset(btf, offset); |
| const char *src_limit; |
| |
| if (!__btf_name_char_ok(*src, true)) |
| return false; |
| |
| /* set a limit on identifier length */ |
| src_limit = src + KSYM_NAME_LEN; |
| src++; |
| while (*src && src < src_limit) { |
| if (!__btf_name_char_ok(*src, false)) |
| return false; |
| src++; |
| } |
| |
| return !*src; |
| } |
| |
| /* Allow any printable character in DATASEC names */ |
| static bool btf_name_valid_section(const struct btf *btf, u32 offset) |
| { |
| /* offset must be valid */ |
| const char *src = btf_str_by_offset(btf, offset); |
| const char *src_limit; |
| |
| if (!*src) |
| return false; |
| |
| /* set a limit on identifier length */ |
| src_limit = src + KSYM_NAME_LEN; |
| while (*src && src < src_limit) { |
| if (!isprint(*src)) |
| return false; |
| src++; |
| } |
| |
| return !*src; |
| } |
| |
| static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) |
| { |
| const char *name; |
| |
| if (!offset) |
| return "(anon)"; |
| |
| name = btf_str_by_offset(btf, offset); |
| return name ?: "(invalid-name-offset)"; |
| } |
| |
| const char *btf_name_by_offset(const struct btf *btf, u32 offset) |
| { |
| return btf_str_by_offset(btf, offset); |
| } |
| |
| const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) |
| { |
| while (type_id < btf->start_id) |
| btf = btf->base_btf; |
| |
| type_id -= btf->start_id; |
| if (type_id >= btf->nr_types) |
| return NULL; |
| return btf->types[type_id]; |
| } |
| EXPORT_SYMBOL_GPL(btf_type_by_id); |
| |
| /* |
| * Regular int is not a bit field and it must be either |
| * u8/u16/u32/u64 or __int128. |
| */ |
| static bool btf_type_int_is_regular(const struct btf_type *t) |
| { |
| u8 nr_bits, nr_bytes; |
| u32 int_data; |
| |
| int_data = btf_type_int(t); |
| nr_bits = BTF_INT_BITS(int_data); |
| nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); |
| if (BITS_PER_BYTE_MASKED(nr_bits) || |
| BTF_INT_OFFSET(int_data) || |
| (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && |
| nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && |
| nr_bytes != (2 * sizeof(u64)))) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| /* |
| * Check that given struct member is a regular int with expected |
| * offset and size. |
| */ |
| bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, |
| const struct btf_member *m, |
| u32 expected_offset, u32 expected_size) |
| { |
| const struct btf_type *t; |
| u32 id, int_data; |
| u8 nr_bits; |
| |
| id = m->type; |
| t = btf_type_id_size(btf, &id, NULL); |
| if (!t || !btf_type_is_int(t)) |
| return false; |
| |
| int_data = btf_type_int(t); |
| nr_bits = BTF_INT_BITS(int_data); |
| if (btf_type_kflag(s)) { |
| u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); |
| u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); |
| |
| /* if kflag set, int should be a regular int and |
| * bit offset should be at byte boundary. |
| */ |
| return !bitfield_size && |
| BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && |
| BITS_ROUNDUP_BYTES(nr_bits) == expected_size; |
| } |
| |
| if (BTF_INT_OFFSET(int_data) || |
| BITS_PER_BYTE_MASKED(m->offset) || |
| BITS_ROUNDUP_BYTES(m->offset) != expected_offset || |
| BITS_PER_BYTE_MASKED(nr_bits) || |
| BITS_ROUNDUP_BYTES(nr_bits) != expected_size) |
| return false; |
| |
| return true; |
| } |
| |
| /* Similar to btf_type_skip_modifiers() but does not skip typedefs. */ |
| static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf, |
| u32 id) |
| { |
| const struct btf_type *t = btf_type_by_id(btf, id); |
| |
| while (btf_type_is_modifier(t) && |
| BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) { |
| t = btf_type_by_id(btf, t->type); |
| } |
| |
| return t; |
| } |
| |
| #define BTF_SHOW_MAX_ITER 10 |
| |
| #define BTF_KIND_BIT(kind) (1ULL << kind) |
| |
| /* |
| * Populate show->state.name with type name information. |
| * Format of type name is |
| * |
| * [.member_name = ] (type_name) |
| */ |
| static const char *btf_show_name(struct btf_show *show) |
| { |
| /* BTF_MAX_ITER array suffixes "[]" */ |
| const char *array_suffixes = "[][][][][][][][][][]"; |
| const char *array_suffix = &array_suffixes[strlen(array_suffixes)]; |
| /* BTF_MAX_ITER pointer suffixes "*" */ |
| const char *ptr_suffixes = "**********"; |
| const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)]; |
| const char *name = NULL, *prefix = "", *parens = ""; |
| const struct btf_member *m = show->state.member; |
| const struct btf_type *t; |
| const struct btf_array *array; |
| u32 id = show->state.type_id; |
| const char *member = NULL; |
| bool show_member = false; |
| u64 kinds = 0; |
| int i; |
| |
| show->state.name[0] = '\0'; |
| |
| /* |
| * Don't show type name if we're showing an array member; |
| * in that case we show the array type so don't need to repeat |
| * ourselves for each member. |
| */ |
| if (show->state.array_member) |
| return ""; |
| |
| /* Retrieve member name, if any. */ |
| if (m) { |
| member = btf_name_by_offset(show->btf, m->name_off); |
| show_member = strlen(member) > 0; |
| id = m->type; |
| } |
| |
| /* |
| * Start with type_id, as we have resolved the struct btf_type * |
| * via btf_modifier_show() past the parent typedef to the child |
| * struct, int etc it is defined as. In such cases, the type_id |
| * still represents the starting type while the struct btf_type * |
| * in our show->state points at the resolved type of the typedef. |
| */ |
| t = btf_type_by_id(show->btf, id); |
| if (!t) |
| return ""; |
| |
| /* |
| * The goal here is to build up the right number of pointer and |
| * array suffixes while ensuring the type name for a typedef |
| * is represented. Along the way we accumulate a list of |
| * BTF kinds we have encountered, since these will inform later |
| * display; for example, pointer types will not require an |
| * opening "{" for struct, we will just display the pointer value. |
| * |
| * We also want to accumulate the right number of pointer or array |
| * indices in the format string while iterating until we get to |
| * the typedef/pointee/array member target type. |
| * |
| * We start by pointing at the end of pointer and array suffix |
| * strings; as we accumulate pointers and arrays we move the pointer |
| * or array string backwards so it will show the expected number of |
| * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers |
| * and/or arrays and typedefs are supported as a precaution. |
| * |
| * We also want to get typedef name while proceeding to resolve |
| * type it points to so that we can add parentheses if it is a |
| * "typedef struct" etc. |
| */ |
| for (i = 0; i < BTF_SHOW_MAX_ITER; i++) { |
| |
| switch (BTF_INFO_KIND(t->info)) { |
| case BTF_KIND_TYPEDEF: |
| if (!name) |
| name = btf_name_by_offset(show->btf, |
| t->name_off); |
| kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF); |
| id = t->type; |
| break; |
| case BTF_KIND_ARRAY: |
| kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY); |
| parens = "["; |
| if (!t) |
| return ""; |
| array = btf_type_array(t); |
| if (array_suffix > array_suffixes) |
| array_suffix -= 2; |
| id = array->type; |
| break; |
| case BTF_KIND_PTR: |
| kinds |= BTF_KIND_BIT(BTF_KIND_PTR); |
| if (ptr_suffix > ptr_suffixes) |
| ptr_suffix -= 1; |
| id = t->type; |
| break; |
| default: |
| id = 0; |
| break; |
| } |
| if (!id) |
| break; |
| t = btf_type_skip_qualifiers(show->btf, id); |
| } |
| /* We may not be able to represent this type; bail to be safe */ |
| if (i == BTF_SHOW_MAX_ITER) |
| return ""; |
| |
| if (!name) |
| name = btf_name_by_offset(show->btf, t->name_off); |
| |
| switch (BTF_INFO_KIND(t->info)) { |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ? |
| "struct" : "union"; |
| /* if it's an array of struct/union, parens is already set */ |
| if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY)))) |
| parens = "{"; |
| break; |
| case BTF_KIND_ENUM: |
| case BTF_KIND_ENUM64: |
| prefix = "enum"; |
| break; |
| default: |
| break; |
| } |
| |
| /* pointer does not require parens */ |
| if (kinds & BTF_KIND_BIT(BTF_KIND_PTR)) |
| parens = ""; |
| /* typedef does not require struct/union/enum prefix */ |
| if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF)) |
| prefix = ""; |
| |
| if (!name) |
| name = ""; |
| |
| /* Even if we don't want type name info, we want parentheses etc */ |
| if (show->flags & BTF_SHOW_NONAME) |
| snprintf(show->state.name, sizeof(show->state.name), "%s", |
| parens); |
| else |
| snprintf(show->state.name, sizeof(show->state.name), |
| "%s%s%s(%s%s%s%s%s%s)%s", |
| /* first 3 strings comprise ".member = " */ |
| show_member ? "." : "", |
| show_member ? member : "", |
| show_member ? " = " : "", |
| /* ...next is our prefix (struct, enum, etc) */ |
| prefix, |
| strlen(prefix) > 0 && strlen(name) > 0 ? " " : "", |
| /* ...this is the type name itself */ |
| name, |
| /* ...suffixed by the appropriate '*', '[]' suffixes */ |
| strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix, |
| array_suffix, parens); |
| |
| return show->state.name; |
| } |
| |
| static const char *__btf_show_indent(struct btf_show *show) |
| { |
| const char *indents = " "; |
| const char *indent = &indents[strlen(indents)]; |
| |
| if ((indent - show->state.depth) >= indents) |
| return indent - show->state.depth; |
| return indents; |
| } |
| |
| static const char *btf_show_indent(struct btf_show *show) |
| { |
| return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show); |
| } |
| |
| static const char *btf_show_newline(struct btf_show *show) |
| { |
| return show->flags & BTF_SHOW_COMPACT ? "" : "\n"; |
| } |
| |
| static const char *btf_show_delim(struct btf_show *show) |
| { |
| if (show->state.depth == 0) |
| return ""; |
| |
| if ((show->flags & BTF_SHOW_COMPACT) && show->state.type && |
| BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION) |
| return "|"; |
| |
| return ","; |
| } |
| |
| __printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...) |
| { |
| va_list args; |
| |
| if (!show->state.depth_check) { |
| va_start(args, fmt); |
| show->showfn(show, fmt, args); |
| va_end(args); |
| } |
| } |
| |
| /* Macros are used here as btf_show_type_value[s]() prepends and appends |
| * format specifiers to the format specifier passed in; these do the work of |
| * adding indentation, delimiters etc while the caller simply has to specify |
| * the type value(s) in the format specifier + value(s). |
| */ |
| #define btf_show_type_value(show, fmt, value) \ |
| do { \ |
| if ((value) != (__typeof__(value))0 || \ |
| (show->flags & BTF_SHOW_ZERO) || \ |
| show->state.depth == 0) { \ |
| btf_show(show, "%s%s" fmt "%s%s", \ |
| btf_show_indent(show), \ |
| btf_show_name(show), \ |
| value, btf_show_delim(show), \ |
| btf_show_newline(show)); \ |
| if (show->state.depth > show->state.depth_to_show) \ |
| show->state.depth_to_show = show->state.depth; \ |
| } \ |
| } while (0) |
| |
| #define btf_show_type_values(show, fmt, ...) \ |
| do { \ |
| btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \ |
| btf_show_name(show), \ |
| __VA_ARGS__, btf_show_delim(show), \ |
| btf_show_newline(show)); \ |
| if (show->state.depth > show->state.depth_to_show) \ |
| show->state.depth_to_show = show->state.depth; \ |
| } while (0) |
| |
| /* How much is left to copy to safe buffer after @data? */ |
| static int btf_show_obj_size_left(struct btf_show *show, void *data) |
| { |
| return show->obj.head + show->obj.size - data; |
| } |
| |
| /* Is object pointed to by @data of @size already copied to our safe buffer? */ |
| static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size) |
| { |
| return data >= show->obj.data && |
| (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE); |
| } |
| |
| /* |
| * If object pointed to by @data of @size falls within our safe buffer, return |
| * the equivalent pointer to the same safe data. Assumes |
| * copy_from_kernel_nofault() has already happened and our safe buffer is |
| * populated. |
| */ |
| static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size) |
| { |
| if (btf_show_obj_is_safe(show, data, size)) |
| return show->obj.safe + (data - show->obj.data); |
| return NULL; |
| } |
| |
| /* |
| * Return a safe-to-access version of data pointed to by @data. |
| * We do this by copying the relevant amount of information |
| * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault(). |
| * |
| * If BTF_SHOW_UNSAFE is specified, just return data as-is; no |
| * safe copy is needed. |
| * |
| * Otherwise we need to determine if we have the required amount |
| * of data (determined by the @data pointer and the size of the |
| * largest base type we can encounter (represented by |
| * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures |
| * that we will be able to print some of the current object, |
| * and if more is needed a copy will be triggered. |
| * Some objects such as structs will not fit into the buffer; |
| * in such cases additional copies when we iterate over their |
| * members may be needed. |
| * |
| * btf_show_obj_safe() is used to return a safe buffer for |
| * btf_show_start_type(); this ensures that as we recurse into |
| * nested types we always have safe data for the given type. |
| * This approach is somewhat wasteful; it's possible for example |
| * that when iterating over a large union we'll end up copying the |
| * same data repeatedly, but the goal is safety not performance. |
| * We use stack data as opposed to per-CPU buffers because the |
| * iteration over a type can take some time, and preemption handling |
| * would greatly complicate use of the safe buffer. |
| */ |
| static void *btf_show_obj_safe(struct btf_show *show, |
| const struct btf_type *t, |
| void *data) |
| { |
| const struct btf_type *rt; |
| int size_left, size; |
| void *safe = NULL; |
| |
| if (show->flags & BTF_SHOW_UNSAFE) |
| return data; |
| |
| rt = btf_resolve_size(show->btf, t, &size); |
| if (IS_ERR(rt)) { |
| show->state.status = PTR_ERR(rt); |
| return NULL; |
| } |
| |
| /* |
| * Is this toplevel object? If so, set total object size and |
| * initialize pointers. Otherwise check if we still fall within |
| * our safe object data. |
| */ |
| if (show->state.depth == 0) { |
| show->obj.size = size; |
| show->obj.head = data; |
| } else { |
| /* |
| * If the size of the current object is > our remaining |
| * safe buffer we _may_ need to do a new copy. However |
| * consider the case of a nested struct; it's size pushes |
| * us over the safe buffer limit, but showing any individual |
| * struct members does not. In such cases, we don't need |
| * to initiate a fresh copy yet; however we definitely need |
| * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left |
| * in our buffer, regardless of the current object size. |
| * The logic here is that as we resolve types we will |
| * hit a base type at some point, and we need to be sure |
| * the next chunk of data is safely available to display |
| * that type info safely. We cannot rely on the size of |
| * the current object here because it may be much larger |
| * than our current buffer (e.g. task_struct is 8k). |
| * All we want to do here is ensure that we can print the |
| * next basic type, which we can if either |
| * - the current type size is within the safe buffer; or |
| * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in |
| * the safe buffer. |
| */ |
| safe = __btf_show_obj_safe(show, data, |
| min(size, |
| BTF_SHOW_OBJ_BASE_TYPE_SIZE)); |
| } |
| |
| /* |
| * We need a new copy to our safe object, either because we haven't |
| * yet copied and are initializing safe data, or because the data |
| * we want falls outside the boundaries of the safe object. |
| */ |
| if (!safe) { |
| size_left = btf_show_obj_size_left(show, data); |
| if (size_left > BTF_SHOW_OBJ_SAFE_SIZE) |
| size_left = BTF_SHOW_OBJ_SAFE_SIZE; |
| show->state.status = copy_from_kernel_nofault(show->obj.safe, |
| data, size_left); |
| if (!show->state.status) { |
| show->obj.data = data; |
| safe = show->obj.safe; |
| } |
| } |
| |
| return safe; |
| } |
| |
| /* |
| * Set the type we are starting to show and return a safe data pointer |
| * to be used for showing the associated data. |
| */ |
| static void *btf_show_start_type(struct btf_show *show, |
| const struct btf_type *t, |
| u32 type_id, void *data) |
| { |
| show->state.type = t; |
| show->state.type_id = type_id; |
| show->state.name[0] = '\0'; |
| |
| return btf_show_obj_safe(show, t, data); |
| } |
| |
| static void btf_show_end_type(struct btf_show *show) |
| { |
| show->state.type = NULL; |
| show->state.type_id = 0; |
| show->state.name[0] = '\0'; |
| } |
| |
| static void *btf_show_start_aggr_type(struct btf_show *show, |
| const struct btf_type *t, |
| u32 type_id, void *data) |
| { |
| void *safe_data = btf_show_start_type(show, t, type_id, data); |
| |
| if (!safe_data) |
| return safe_data; |
| |
| btf_show(show, "%s%s%s", btf_show_indent(show), |
| btf_show_name(show), |
| btf_show_newline(show)); |
| show->state.depth++; |
| return safe_data; |
| } |
| |
| static void btf_show_end_aggr_type(struct btf_show *show, |
| const char *suffix) |
| { |
| show->state.depth--; |
| btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix, |
| btf_show_delim(show), btf_show_newline(show)); |
| btf_show_end_type(show); |
| } |
| |
| static void btf_show_start_member(struct btf_show *show, |
| const struct btf_member *m) |
| { |
| show->state.member = m; |
| } |
| |
| static void btf_show_start_array_member(struct btf_show *show) |
| { |
| show->state.array_member = 1; |
| btf_show_start_member(show, NULL); |
| } |
| |
| static void btf_show_end_member(struct btf_show *show) |
| { |
| show->state.member = NULL; |
| } |
| |
| static void btf_show_end_array_member(struct btf_show *show) |
| { |
| show->state.array_member = 0; |
| btf_show_end_member(show); |
| } |
| |
| static void *btf_show_start_array_type(struct btf_show *show, |
| const struct btf_type *t, |
| u32 type_id, |
| u16 array_encoding, |
| void *data) |
| { |
| show->state.array_encoding = array_encoding; |
| show->state.array_terminated = 0; |
| return btf_show_start_aggr_type(show, t, type_id, data); |
| } |
| |
| static void btf_show_end_array_type(struct btf_show *show) |
| { |
| show->state.array_encoding = 0; |
| show->state.array_terminated = 0; |
| btf_show_end_aggr_type(show, "]"); |
| } |
| |
| static void *btf_show_start_struct_type(struct btf_show *show, |
| const struct btf_type *t, |
| u32 type_id, |
| void *data) |
| { |
| return btf_show_start_aggr_type(show, t, type_id, data); |
| } |
| |
| static void btf_show_end_struct_type(struct btf_show *show) |
| { |
| btf_show_end_aggr_type(show, "}"); |
| } |
| |
| __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, |
| const char *fmt, ...) |
| { |
| va_list args; |
| |
| va_start(args, fmt); |
| bpf_verifier_vlog(log, fmt, args); |
| va_end(args); |
| } |
| |
| __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, |
| const char *fmt, ...) |
| { |
| struct bpf_verifier_log *log = &env->log; |
| va_list args; |
| |
| if (!bpf_verifier_log_needed(log)) |
| return; |
| |
| va_start(args, fmt); |
| bpf_verifier_vlog(log, fmt, args); |
| va_end(args); |
| } |
| |
| __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| bool log_details, |
| const char *fmt, ...) |
| { |
| struct bpf_verifier_log *log = &env->log; |
| struct btf *btf = env->btf; |
| va_list args; |
| |
| if (!bpf_verifier_log_needed(log)) |
| return; |
| |
| if (log->level == BPF_LOG_KERNEL) { |
| /* btf verifier prints all types it is processing via |
| * btf_verifier_log_type(..., fmt = NULL). |
| * Skip those prints for in-kernel BTF verification. |
| */ |
| if (!fmt) |
| return; |
| |
| /* Skip logging when loading module BTF with mismatches permitted */ |
| if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
| return; |
| } |
| |
| __btf_verifier_log(log, "[%u] %s %s%s", |
| env->log_type_id, |
| btf_type_str(t), |
| __btf_name_by_offset(btf, t->name_off), |
| log_details ? " " : ""); |
| |
| if (log_details) |
| btf_type_ops(t)->log_details(env, t); |
| |
| if (fmt && *fmt) { |
| __btf_verifier_log(log, " "); |
| va_start(args, fmt); |
| bpf_verifier_vlog(log, fmt, args); |
| va_end(args); |
| } |
| |
| __btf_verifier_log(log, "\n"); |
| } |
| |
| #define btf_verifier_log_type(env, t, ...) \ |
| __btf_verifier_log_type((env), (t), true, __VA_ARGS__) |
| #define btf_verifier_log_basic(env, t, ...) \ |
| __btf_verifier_log_type((env), (t), false, __VA_ARGS__) |
| |
| __printf(4, 5) |
| static void btf_verifier_log_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const char *fmt, ...) |
| { |
| struct bpf_verifier_log *log = &env->log; |
| struct btf *btf = env->btf; |
| va_list args; |
| |
| if (!bpf_verifier_log_needed(log)) |
| return; |
| |
| if (log->level == BPF_LOG_KERNEL) { |
| if (!fmt) |
| return; |
| |
| /* Skip logging when loading module BTF with mismatches permitted */ |
| if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) |
| return; |
| } |
| |
| /* The CHECK_META phase already did a btf dump. |
| * |
| * If member is logged again, it must hit an error in |
| * parsing this member. It is useful to print out which |
| * struct this member belongs to. |
| */ |
| if (env->phase != CHECK_META) |
| btf_verifier_log_type(env, struct_type, NULL); |
| |
| if (btf_type_kflag(struct_type)) |
| __btf_verifier_log(log, |
| "\t%s type_id=%u bitfield_size=%u bits_offset=%u", |
| __btf_name_by_offset(btf, member->name_off), |
| member->type, |
| BTF_MEMBER_BITFIELD_SIZE(member->offset), |
| BTF_MEMBER_BIT_OFFSET(member->offset)); |
| else |
| __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", |
| __btf_name_by_offset(btf, member->name_off), |
| member->type, member->offset); |
| |
| if (fmt && *fmt) { |
| __btf_verifier_log(log, " "); |
| va_start(args, fmt); |
| bpf_verifier_vlog(log, fmt, args); |
| va_end(args); |
| } |
| |
| __btf_verifier_log(log, "\n"); |
| } |
| |
| __printf(4, 5) |
| static void btf_verifier_log_vsi(struct btf_verifier_env *env, |
| const struct btf_type *datasec_type, |
| const struct btf_var_secinfo *vsi, |
| const char *fmt, ...) |
| { |
| struct bpf_verifier_log *log = &env->log; |
| va_list args; |
| |
| if (!bpf_verifier_log_needed(log)) |
| return; |
| if (log->level == BPF_LOG_KERNEL && !fmt) |
| return; |
| if (env->phase != CHECK_META) |
| btf_verifier_log_type(env, datasec_type, NULL); |
| |
| __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", |
| vsi->type, vsi->offset, vsi->size); |
| if (fmt && *fmt) { |
| __btf_verifier_log(log, " "); |
| va_start(args, fmt); |
| bpf_verifier_vlog(log, fmt, args); |
| va_end(args); |
| } |
| |
| __btf_verifier_log(log, "\n"); |
| } |
| |
| static void btf_verifier_log_hdr(struct btf_verifier_env *env, |
| u32 btf_data_size) |
| { |
| struct bpf_verifier_log *log = &env->log; |
| const struct btf *btf = env->btf; |
| const struct btf_header *hdr; |
| |
| if (!bpf_verifier_log_needed(log)) |
| return; |
| |
| if (log->level == BPF_LOG_KERNEL) |
| return; |
| hdr = &btf->hdr; |
| __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); |
| __btf_verifier_log(log, "version: %u\n", hdr->version); |
| __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); |
| __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); |
| __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); |
| __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); |
| __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); |
| __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); |
| __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); |
| } |
| |
| static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) |
| { |
| struct btf *btf = env->btf; |
| |
| if (btf->types_size == btf->nr_types) { |
| /* Expand 'types' array */ |
| |
| struct btf_type **new_types; |
| u32 expand_by, new_size; |
| |
| if (btf->start_id + btf->types_size == BTF_MAX_TYPE) { |
| btf_verifier_log(env, "Exceeded max num of types"); |
| return -E2BIG; |
| } |
| |
| expand_by = max_t(u32, btf->types_size >> 2, 16); |
| new_size = min_t(u32, BTF_MAX_TYPE, |
| btf->types_size + expand_by); |
| |
| new_types = kvcalloc(new_size, sizeof(*new_types), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!new_types) |
| return -ENOMEM; |
| |
| if (btf->nr_types == 0) { |
| if (!btf->base_btf) { |
| /* lazily init VOID type */ |
| new_types[0] = &btf_void; |
| btf->nr_types++; |
| } |
| } else { |
| memcpy(new_types, btf->types, |
| sizeof(*btf->types) * btf->nr_types); |
| } |
| |
| kvfree(btf->types); |
| btf->types = new_types; |
| btf->types_size = new_size; |
| } |
| |
| btf->types[btf->nr_types++] = t; |
| |
| return 0; |
| } |
| |
| static int btf_alloc_id(struct btf *btf) |
| { |
| int id; |
| |
| idr_preload(GFP_KERNEL); |
| spin_lock_bh(&btf_idr_lock); |
| id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); |
| if (id > 0) |
| btf->id = id; |
| spin_unlock_bh(&btf_idr_lock); |
| idr_preload_end(); |
| |
| if (WARN_ON_ONCE(!id)) |
| return -ENOSPC; |
| |
| return id > 0 ? 0 : id; |
| } |
| |
| static void btf_free_id(struct btf *btf) |
| { |
| unsigned long flags; |
| |
| /* |
| * In map-in-map, calling map_delete_elem() on outer |
| * map will call bpf_map_put on the inner map. |
| * It will then eventually call btf_free_id() |
| * on the inner map. Some of the map_delete_elem() |
| * implementation may have irq disabled, so |
| * we need to use the _irqsave() version instead |
| * of the _bh() version. |
| */ |
| spin_lock_irqsave(&btf_idr_lock, flags); |
| idr_remove(&btf_idr, btf->id); |
| spin_unlock_irqrestore(&btf_idr_lock, flags); |
| } |
| |
| static void btf_free_kfunc_set_tab(struct btf *btf) |
| { |
| struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab; |
| int hook; |
| |
| if (!tab) |
| return; |
| for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++) |
| kfree(tab->sets[hook]); |
| kfree(tab); |
| btf->kfunc_set_tab = NULL; |
| } |
| |
| static void btf_free_dtor_kfunc_tab(struct btf *btf) |
| { |
| struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; |
| |
| if (!tab) |
| return; |
| kfree(tab); |
| btf->dtor_kfunc_tab = NULL; |
| } |
| |
| static void btf_struct_metas_free(struct btf_struct_metas *tab) |
| { |
| int i; |
| |
| if (!tab) |
| return; |
| for (i = 0; i < tab->cnt; i++) |
| btf_record_free(tab->types[i].record); |
| kfree(tab); |
| } |
| |
| static void btf_free_struct_meta_tab(struct btf *btf) |
| { |
| struct btf_struct_metas *tab = btf->struct_meta_tab; |
| |
| btf_struct_metas_free(tab); |
| btf->struct_meta_tab = NULL; |
| } |
| |
| static void btf_free_struct_ops_tab(struct btf *btf) |
| { |
| struct btf_struct_ops_tab *tab = btf->struct_ops_tab; |
| u32 i; |
| |
| if (!tab) |
| return; |
| |
| for (i = 0; i < tab->cnt; i++) |
| bpf_struct_ops_desc_release(&tab->ops[i]); |
| |
| kfree(tab); |
| btf->struct_ops_tab = NULL; |
| } |
| |
| static void btf_free(struct btf *btf) |
| { |
| btf_free_struct_meta_tab(btf); |
| btf_free_dtor_kfunc_tab(btf); |
| btf_free_kfunc_set_tab(btf); |
| btf_free_struct_ops_tab(btf); |
| kvfree(btf->types); |
| kvfree(btf->resolved_sizes); |
| kvfree(btf->resolved_ids); |
| /* vmlinux does not allocate btf->data, it simply points it at |
| * __start_BTF. |
| */ |
| if (!btf_is_vmlinux(btf)) |
| kvfree(btf->data); |
| kvfree(btf->base_id_map); |
| kfree(btf); |
| } |
| |
| static void btf_free_rcu(struct rcu_head *rcu) |
| { |
| struct btf *btf = container_of(rcu, struct btf, rcu); |
| |
| btf_free(btf); |
| } |
| |
| const char *btf_get_name(const struct btf *btf) |
| { |
| return btf->name; |
| } |
| |
| void btf_get(struct btf *btf) |
| { |
| refcount_inc(&btf->refcnt); |
| } |
| |
| void btf_put(struct btf *btf) |
| { |
| if (btf && refcount_dec_and_test(&btf->refcnt)) { |
| btf_free_id(btf); |
| call_rcu(&btf->rcu, btf_free_rcu); |
| } |
| } |
| |
| struct btf *btf_base_btf(const struct btf *btf) |
| { |
| return btf->base_btf; |
| } |
| |
| const struct btf_header *btf_header(const struct btf *btf) |
| { |
| return &btf->hdr; |
| } |
| |
| void btf_set_base_btf(struct btf *btf, const struct btf *base_btf) |
| { |
| btf->base_btf = (struct btf *)base_btf; |
| btf->start_id = btf_nr_types(base_btf); |
| btf->start_str_off = base_btf->hdr.str_len; |
| } |
| |
| static int env_resolve_init(struct btf_verifier_env *env) |
| { |
| struct btf *btf = env->btf; |
| u32 nr_types = btf->nr_types; |
| u32 *resolved_sizes = NULL; |
| u32 *resolved_ids = NULL; |
| u8 *visit_states = NULL; |
| |
| resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!resolved_sizes) |
| goto nomem; |
| |
| resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!resolved_ids) |
| goto nomem; |
| |
| visit_states = kvcalloc(nr_types, sizeof(*visit_states), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!visit_states) |
| goto nomem; |
| |
| btf->resolved_sizes = resolved_sizes; |
| btf->resolved_ids = resolved_ids; |
| env->visit_states = visit_states; |
| |
| return 0; |
| |
| nomem: |
| kvfree(resolved_sizes); |
| kvfree(resolved_ids); |
| kvfree(visit_states); |
| return -ENOMEM; |
| } |
| |
| static void btf_verifier_env_free(struct btf_verifier_env *env) |
| { |
| kvfree(env->visit_states); |
| kfree(env); |
| } |
| |
| static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, |
| const struct btf_type *next_type) |
| { |
| switch (env->resolve_mode) { |
| case RESOLVE_TBD: |
| /* int, enum or void is a sink */ |
| return !btf_type_needs_resolve(next_type); |
| case RESOLVE_PTR: |
| /* int, enum, void, struct, array, func or func_proto is a sink |
| * for ptr |
| */ |
| return !btf_type_is_modifier(next_type) && |
| !btf_type_is_ptr(next_type); |
| case RESOLVE_STRUCT_OR_ARRAY: |
| /* int, enum, void, ptr, func or func_proto is a sink |
| * for struct and array |
| */ |
| return !btf_type_is_modifier(next_type) && |
| !btf_type_is_array(next_type) && |
| !btf_type_is_struct(next_type); |
| default: |
| BUG(); |
| } |
| } |
| |
| static bool env_type_is_resolved(const struct btf_verifier_env *env, |
| u32 type_id) |
| { |
| /* base BTF types should be resolved by now */ |
| if (type_id < env->btf->start_id) |
| return true; |
| |
| return env->visit_states[type_id - env->btf->start_id] == RESOLVED; |
| } |
| |
| static int env_stack_push(struct btf_verifier_env *env, |
| const struct btf_type *t, u32 type_id) |
| { |
| const struct btf *btf = env->btf; |
| struct resolve_vertex *v; |
| |
| if (env->top_stack == MAX_RESOLVE_DEPTH) |
| return -E2BIG; |
| |
| if (type_id < btf->start_id |
| || env->visit_states[type_id - btf->start_id] != NOT_VISITED) |
| return -EEXIST; |
| |
| env->visit_states[type_id - btf->start_id] = VISITED; |
| |
| v = &env->stack[env->top_stack++]; |
| v->t = t; |
| v->type_id = type_id; |
| v->next_member = 0; |
| |
| if (env->resolve_mode == RESOLVE_TBD) { |
| if (btf_type_is_ptr(t)) |
| env->resolve_mode = RESOLVE_PTR; |
| else if (btf_type_is_struct(t) || btf_type_is_array(t)) |
| env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; |
| } |
| |
| return 0; |
| } |
| |
| static void env_stack_set_next_member(struct btf_verifier_env *env, |
| u16 next_member) |
| { |
| env->stack[env->top_stack - 1].next_member = next_member; |
| } |
| |
| static void env_stack_pop_resolved(struct btf_verifier_env *env, |
| u32 resolved_type_id, |
| u32 resolved_size) |
| { |
| u32 type_id = env->stack[--(env->top_stack)].type_id; |
| struct btf *btf = env->btf; |
| |
| type_id -= btf->start_id; /* adjust to local type id */ |
| btf->resolved_sizes[type_id] = resolved_size; |
| btf->resolved_ids[type_id] = resolved_type_id; |
| env->visit_states[type_id] = RESOLVED; |
| } |
| |
| static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) |
| { |
| return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; |
| } |
| |
| /* Resolve the size of a passed-in "type" |
| * |
| * type: is an array (e.g. u32 array[x][y]) |
| * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY, |
| * *type_size: (x * y * sizeof(u32)). Hence, *type_size always |
| * corresponds to the return type. |
| * *elem_type: u32 |
| * *elem_id: id of u32 |
| * *total_nelems: (x * y). Hence, individual elem size is |
| * (*type_size / *total_nelems) |
| * *type_id: id of type if it's changed within the function, 0 if not |
| * |
| * type: is not an array (e.g. const struct X) |
| * return type: type "struct X" |
| * *type_size: sizeof(struct X) |
| * *elem_type: same as return type ("struct X") |
| * *elem_id: 0 |
| * *total_nelems: 1 |
| * *type_id: id of type if it's changed within the function, 0 if not |
| */ |
| static const struct btf_type * |
| __btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
| u32 *type_size, const struct btf_type **elem_type, |
| u32 *elem_id, u32 *total_nelems, u32 *type_id) |
| { |
| const struct btf_type *array_type = NULL; |
| const struct btf_array *array = NULL; |
| u32 i, size, nelems = 1, id = 0; |
| |
| for (i = 0; i < MAX_RESOLVE_DEPTH; i++) { |
| switch (BTF_INFO_KIND(type->info)) { |
| /* type->size can be used */ |
| case BTF_KIND_INT: |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| case BTF_KIND_ENUM: |
| case BTF_KIND_FLOAT: |
| case BTF_KIND_ENUM64: |
| size = type->size; |
| goto resolved; |
| |
| case BTF_KIND_PTR: |
| size = sizeof(void *); |
| goto resolved; |
| |
| /* Modifiers */ |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_CONST: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_TYPE_TAG: |
| id = type->type; |
| type = btf_type_by_id(btf, type->type); |
| break; |
| |
| case BTF_KIND_ARRAY: |
| if (!array_type) |
| array_type = type; |
| array = btf_type_array(type); |
| if (nelems && array->nelems > U32_MAX / nelems) |
| return ERR_PTR(-EINVAL); |
| nelems *= array->nelems; |
| type = btf_type_by_id(btf, array->type); |
| break; |
| |
| /* type without size */ |
| default: |
| return ERR_PTR(-EINVAL); |
| } |
| } |
| |
| return ERR_PTR(-EINVAL); |
| |
| resolved: |
| if (nelems && size > U32_MAX / nelems) |
| return ERR_PTR(-EINVAL); |
| |
| *type_size = nelems * size; |
| if (total_nelems) |
| *total_nelems = nelems; |
| if (elem_type) |
| *elem_type = type; |
| if (elem_id) |
| *elem_id = array ? array->type : 0; |
| if (type_id && id) |
| *type_id = id; |
| |
| return array_type ? : type; |
| } |
| |
| const struct btf_type * |
| btf_resolve_size(const struct btf *btf, const struct btf_type *type, |
| u32 *type_size) |
| { |
| return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL); |
| } |
| |
| static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id) |
| { |
| while (type_id < btf->start_id) |
| btf = btf->base_btf; |
| |
| return btf->resolved_ids[type_id - btf->start_id]; |
| } |
| |
| /* The input param "type_id" must point to a needs_resolve type */ |
| static const struct btf_type *btf_type_id_resolve(const struct btf *btf, |
| u32 *type_id) |
| { |
| *type_id = btf_resolved_type_id(btf, *type_id); |
| return btf_type_by_id(btf, *type_id); |
| } |
| |
| static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id) |
| { |
| while (type_id < btf->start_id) |
| btf = btf->base_btf; |
| |
| return btf->resolved_sizes[type_id - btf->start_id]; |
| } |
| |
| const struct btf_type *btf_type_id_size(const struct btf *btf, |
| u32 *type_id, u32 *ret_size) |
| { |
| const struct btf_type *size_type; |
| u32 size_type_id = *type_id; |
| u32 size = 0; |
| |
| size_type = btf_type_by_id(btf, size_type_id); |
| if (btf_type_nosize_or_null(size_type)) |
| return NULL; |
| |
| if (btf_type_has_size(size_type)) { |
| size = size_type->size; |
| } else if (btf_type_is_array(size_type)) { |
| size = btf_resolved_type_size(btf, size_type_id); |
| } else if (btf_type_is_ptr(size_type)) { |
| size = sizeof(void *); |
| } else { |
| if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && |
| !btf_type_is_var(size_type))) |
| return NULL; |
| |
| size_type_id = btf_resolved_type_id(btf, size_type_id); |
| size_type = btf_type_by_id(btf, size_type_id); |
| if (btf_type_nosize_or_null(size_type)) |
| return NULL; |
| else if (btf_type_has_size(size_type)) |
| size = size_type->size; |
| else if (btf_type_is_array(size_type)) |
| size = btf_resolved_type_size(btf, size_type_id); |
| else if (btf_type_is_ptr(size_type)) |
| size = sizeof(void *); |
| else |
| return NULL; |
| } |
| |
| *type_id = size_type_id; |
| if (ret_size) |
| *ret_size = size; |
| |
| return size_type; |
| } |
| |
| static int btf_df_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| btf_verifier_log_basic(env, struct_type, |
| "Unsupported check_member"); |
| return -EINVAL; |
| } |
| |
| static int btf_df_check_kflag_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| btf_verifier_log_basic(env, struct_type, |
| "Unsupported check_kflag_member"); |
| return -EINVAL; |
| } |
| |
| /* Used for ptr, array struct/union and float type members. |
| * int, enum and modifier types have their specific callback functions. |
| */ |
| static int btf_generic_check_kflag_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member bitfield_size"); |
| return -EINVAL; |
| } |
| |
| /* bitfield size is 0, so member->offset represents bit offset only. |
| * It is safe to call non kflag check_member variants. |
| */ |
| return btf_type_ops(member_type)->check_member(env, struct_type, |
| member, |
| member_type); |
| } |
| |
| static int btf_df_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| btf_verifier_log_basic(env, v->t, "Unsupported resolve"); |
| return -EINVAL; |
| } |
| |
| static void btf_df_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offsets, |
| struct btf_show *show) |
| { |
| btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); |
| } |
| |
| static int btf_int_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 int_data = btf_type_int(member_type); |
| u32 struct_bits_off = member->offset; |
| u32 struct_size = struct_type->size; |
| u32 nr_copy_bits; |
| u32 bytes_offset; |
| |
| if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "bits_offset exceeds U32_MAX"); |
| return -EINVAL; |
| } |
| |
| struct_bits_off += BTF_INT_OFFSET(int_data); |
| bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| nr_copy_bits = BTF_INT_BITS(int_data) + |
| BITS_PER_BYTE_MASKED(struct_bits_off); |
| |
| if (nr_copy_bits > BITS_PER_U128) { |
| btf_verifier_log_member(env, struct_type, member, |
| "nr_copy_bits exceeds 128"); |
| return -EINVAL; |
| } |
| |
| if (struct_size < bytes_offset || |
| struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_int_check_kflag_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; |
| u32 int_data = btf_type_int(member_type); |
| u32 struct_size = struct_type->size; |
| u32 nr_copy_bits; |
| |
| /* a regular int type is required for the kflag int member */ |
| if (!btf_type_int_is_regular(member_type)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member base type"); |
| return -EINVAL; |
| } |
| |
| /* check sanity of bitfield size */ |
| nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); |
| struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); |
| nr_int_data_bits = BTF_INT_BITS(int_data); |
| if (!nr_bits) { |
| /* Not a bitfield member, member offset must be at byte |
| * boundary. |
| */ |
| if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member offset"); |
| return -EINVAL; |
| } |
| |
| nr_bits = nr_int_data_bits; |
| } else if (nr_bits > nr_int_data_bits) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member bitfield_size"); |
| return -EINVAL; |
| } |
| |
| bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); |
| if (nr_copy_bits > BITS_PER_U128) { |
| btf_verifier_log_member(env, struct_type, member, |
| "nr_copy_bits exceeds 128"); |
| return -EINVAL; |
| } |
| |
| if (struct_size < bytes_offset || |
| struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static s32 btf_int_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| u32 int_data, nr_bits, meta_needed = sizeof(int_data); |
| u16 encoding; |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| int_data = btf_type_int(t); |
| if (int_data & ~BTF_INT_MASK) { |
| btf_verifier_log_basic(env, t, "Invalid int_data:%x", |
| int_data); |
| return -EINVAL; |
| } |
| |
| nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); |
| |
| if (nr_bits > BITS_PER_U128) { |
| btf_verifier_log_type(env, t, "nr_bits exceeds %zu", |
| BITS_PER_U128); |
| return -EINVAL; |
| } |
| |
| if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { |
| btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); |
| return -EINVAL; |
| } |
| |
| /* |
| * Only one of the encoding bits is allowed and it |
| * should be sufficient for the pretty print purpose (i.e. decoding). |
| * Multiple bits can be allowed later if it is found |
| * to be insufficient. |
| */ |
| encoding = BTF_INT_ENCODING(int_data); |
| if (encoding && |
| encoding != BTF_INT_SIGNED && |
| encoding != BTF_INT_CHAR && |
| encoding != BTF_INT_BOOL) { |
| btf_verifier_log_type(env, t, "Unsupported encoding"); |
| return -ENOTSUPP; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return meta_needed; |
| } |
| |
| static void btf_int_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| int int_data = btf_type_int(t); |
| |
| btf_verifier_log(env, |
| "size=%u bits_offset=%u nr_bits=%u encoding=%s", |
| t->size, BTF_INT_OFFSET(int_data), |
| BTF_INT_BITS(int_data), |
| btf_int_encoding_str(BTF_INT_ENCODING(int_data))); |
| } |
| |
| static void btf_int128_print(struct btf_show *show, void *data) |
| { |
| /* data points to a __int128 number. |
| * Suppose |
| * int128_num = *(__int128 *)data; |
| * The below formulas shows what upper_num and lower_num represents: |
| * upper_num = int128_num >> 64; |
| * lower_num = int128_num & 0xffffffffFFFFFFFFULL; |
| */ |
| u64 upper_num, lower_num; |
| |
| #ifdef __BIG_ENDIAN_BITFIELD |
| upper_num = *(u64 *)data; |
| lower_num = *(u64 *)(data + 8); |
| #else |
| upper_num = *(u64 *)(data + 8); |
| lower_num = *(u64 *)data; |
| #endif |
| if (upper_num == 0) |
| btf_show_type_value(show, "0x%llx", lower_num); |
| else |
| btf_show_type_values(show, "0x%llx%016llx", upper_num, |
| lower_num); |
| } |
| |
| static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, |
| u16 right_shift_bits) |
| { |
| u64 upper_num, lower_num; |
| |
| #ifdef __BIG_ENDIAN_BITFIELD |
| upper_num = print_num[0]; |
| lower_num = print_num[1]; |
| #else |
| upper_num = print_num[1]; |
| lower_num = print_num[0]; |
| #endif |
| |
| /* shake out un-needed bits by shift/or operations */ |
| if (left_shift_bits >= 64) { |
| upper_num = lower_num << (left_shift_bits - 64); |
| lower_num = 0; |
| } else { |
| upper_num = (upper_num << left_shift_bits) | |
| (lower_num >> (64 - left_shift_bits)); |
| lower_num = lower_num << left_shift_bits; |
| } |
| |
| if (right_shift_bits >= 64) { |
| lower_num = upper_num >> (right_shift_bits - 64); |
| upper_num = 0; |
| } else { |
| lower_num = (lower_num >> right_shift_bits) | |
| (upper_num << (64 - right_shift_bits)); |
| upper_num = upper_num >> right_shift_bits; |
| } |
| |
| #ifdef __BIG_ENDIAN_BITFIELD |
| print_num[0] = upper_num; |
| print_num[1] = lower_num; |
| #else |
| print_num[0] = lower_num; |
| print_num[1] = upper_num; |
| #endif |
| } |
| |
| static void btf_bitfield_show(void *data, u8 bits_offset, |
| u8 nr_bits, struct btf_show *show) |
| { |
| u16 left_shift_bits, right_shift_bits; |
| u8 nr_copy_bytes; |
| u8 nr_copy_bits; |
| u64 print_num[2] = {}; |
| |
| nr_copy_bits = nr_bits + bits_offset; |
| nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); |
| |
| memcpy(print_num, data, nr_copy_bytes); |
| |
| #ifdef __BIG_ENDIAN_BITFIELD |
| left_shift_bits = bits_offset; |
| #else |
| left_shift_bits = BITS_PER_U128 - nr_copy_bits; |
| #endif |
| right_shift_bits = BITS_PER_U128 - nr_bits; |
| |
| btf_int128_shift(print_num, left_shift_bits, right_shift_bits); |
| btf_int128_print(show, print_num); |
| } |
| |
| |
| static void btf_int_bits_show(const struct btf *btf, |
| const struct btf_type *t, |
| void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| u32 int_data = btf_type_int(t); |
| u8 nr_bits = BTF_INT_BITS(int_data); |
| u8 total_bits_offset; |
| |
| /* |
| * bits_offset is at most 7. |
| * BTF_INT_OFFSET() cannot exceed 128 bits. |
| */ |
| total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); |
| data += BITS_ROUNDDOWN_BYTES(total_bits_offset); |
| bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); |
| btf_bitfield_show(data, bits_offset, nr_bits, show); |
| } |
| |
| static void btf_int_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| u32 int_data = btf_type_int(t); |
| u8 encoding = BTF_INT_ENCODING(int_data); |
| bool sign = encoding & BTF_INT_SIGNED; |
| u8 nr_bits = BTF_INT_BITS(int_data); |
| void *safe_data; |
| |
| safe_data = btf_show_start_type(show, t, type_id, data); |
| if (!safe_data) |
| return; |
| |
| if (bits_offset || BTF_INT_OFFSET(int_data) || |
| BITS_PER_BYTE_MASKED(nr_bits)) { |
| btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
| goto out; |
| } |
| |
| switch (nr_bits) { |
| case 128: |
| btf_int128_print(show, safe_data); |
| break; |
| case 64: |
| if (sign) |
| btf_show_type_value(show, "%lld", *(s64 *)safe_data); |
| else |
| btf_show_type_value(show, "%llu", *(u64 *)safe_data); |
| break; |
| case 32: |
| if (sign) |
| btf_show_type_value(show, "%d", *(s32 *)safe_data); |
| else |
| btf_show_type_value(show, "%u", *(u32 *)safe_data); |
| break; |
| case 16: |
| if (sign) |
| btf_show_type_value(show, "%d", *(s16 *)safe_data); |
| else |
| btf_show_type_value(show, "%u", *(u16 *)safe_data); |
| break; |
| case 8: |
| if (show->state.array_encoding == BTF_INT_CHAR) { |
| /* check for null terminator */ |
| if (show->state.array_terminated) |
| break; |
| if (*(char *)data == '\0') { |
| show->state.array_terminated = 1; |
| break; |
| } |
| if (isprint(*(char *)data)) { |
| btf_show_type_value(show, "'%c'", |
| *(char *)safe_data); |
| break; |
| } |
| } |
| if (sign) |
| btf_show_type_value(show, "%d", *(s8 *)safe_data); |
| else |
| btf_show_type_value(show, "%u", *(u8 *)safe_data); |
| break; |
| default: |
| btf_int_bits_show(btf, t, safe_data, bits_offset, show); |
| break; |
| } |
| out: |
| btf_show_end_type(show); |
| } |
| |
| static const struct btf_kind_operations int_ops = { |
| .check_meta = btf_int_check_meta, |
| .resolve = btf_df_resolve, |
| .check_member = btf_int_check_member, |
| .check_kflag_member = btf_int_check_kflag_member, |
| .log_details = btf_int_log, |
| .show = btf_int_show, |
| }; |
| |
| static int btf_modifier_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| const struct btf_type *resolved_type; |
| u32 resolved_type_id = member->type; |
| struct btf_member resolved_member; |
| struct btf *btf = env->btf; |
| |
| resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); |
| if (!resolved_type) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member"); |
| return -EINVAL; |
| } |
| |
| resolved_member = *member; |
| resolved_member.type = resolved_type_id; |
| |
| return btf_type_ops(resolved_type)->check_member(env, struct_type, |
| &resolved_member, |
| resolved_type); |
| } |
| |
| static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| const struct btf_type *resolved_type; |
| u32 resolved_type_id = member->type; |
| struct btf_member resolved_member; |
| struct btf *btf = env->btf; |
| |
| resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); |
| if (!resolved_type) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member"); |
| return -EINVAL; |
| } |
| |
| resolved_member = *member; |
| resolved_member.type = resolved_type_id; |
| |
| return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, |
| &resolved_member, |
| resolved_type); |
| } |
| |
| static int btf_ptr_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 struct_size, struct_bits_off, bytes_offset; |
| |
| struct_size = struct_type->size; |
| struct_bits_off = member->offset; |
| bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| |
| if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member is not byte aligned"); |
| return -EINVAL; |
| } |
| |
| if (struct_size - bytes_offset < sizeof(void *)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_ref_type_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const char *value; |
| |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| if (!BTF_TYPE_ID_VALID(t->type)) { |
| btf_verifier_log_type(env, t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| /* typedef/type_tag type must have a valid name, and other ref types, |
| * volatile, const, restrict, should have a null name. |
| */ |
| if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { |
| if (!t->name_off || |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) { |
| value = btf_name_by_offset(env->btf, t->name_off); |
| if (!value || !value[0]) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| } else { |
| if (t->name_off) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return 0; |
| } |
| |
| static int btf_modifier_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_type *t = v->t; |
| const struct btf_type *next_type; |
| u32 next_type_id = t->type; |
| struct btf *btf = env->btf; |
| |
| next_type = btf_type_by_id(btf, next_type_id); |
| if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, next_type) && |
| !env_type_is_resolved(env, next_type_id)) |
| return env_stack_push(env, next_type, next_type_id); |
| |
| /* Figure out the resolved next_type_id with size. |
| * They will be stored in the current modifier's |
| * resolved_ids and resolved_sizes such that it can |
| * save us a few type-following when we use it later (e.g. in |
| * pretty print). |
| */ |
| if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
| if (env_type_is_resolved(env, next_type_id)) |
| next_type = btf_type_id_resolve(btf, &next_type_id); |
| |
| /* "typedef void new_void", "const void"...etc */ |
| if (!btf_type_is_void(next_type) && |
| !btf_type_is_fwd(next_type) && |
| !btf_type_is_func_proto(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| } |
| |
| env_stack_pop_resolved(env, next_type_id, 0); |
| |
| return 0; |
| } |
| |
| static int btf_var_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_type *next_type; |
| const struct btf_type *t = v->t; |
| u32 next_type_id = t->type; |
| struct btf *btf = env->btf; |
| |
| next_type = btf_type_by_id(btf, next_type_id); |
| if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, next_type) && |
| !env_type_is_resolved(env, next_type_id)) |
| return env_stack_push(env, next_type, next_type_id); |
| |
| if (btf_type_is_modifier(next_type)) { |
| const struct btf_type *resolved_type; |
| u32 resolved_type_id; |
| |
| resolved_type_id = next_type_id; |
| resolved_type = btf_type_id_resolve(btf, &resolved_type_id); |
| |
| if (btf_type_is_ptr(resolved_type) && |
| !env_type_is_resolve_sink(env, resolved_type) && |
| !env_type_is_resolved(env, resolved_type_id)) |
| return env_stack_push(env, resolved_type, |
| resolved_type_id); |
| } |
| |
| /* We must resolve to something concrete at this point, no |
| * forward types or similar that would resolve to size of |
| * zero is allowed. |
| */ |
| if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| env_stack_pop_resolved(env, next_type_id, 0); |
| |
| return 0; |
| } |
| |
| static int btf_ptr_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_type *next_type; |
| const struct btf_type *t = v->t; |
| u32 next_type_id = t->type; |
| struct btf *btf = env->btf; |
| |
| next_type = btf_type_by_id(btf, next_type_id); |
| if (!next_type || btf_type_is_resolve_source_only(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, next_type) && |
| !env_type_is_resolved(env, next_type_id)) |
| return env_stack_push(env, next_type, next_type_id); |
| |
| /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, |
| * the modifier may have stopped resolving when it was resolved |
| * to a ptr (last-resolved-ptr). |
| * |
| * We now need to continue from the last-resolved-ptr to |
| * ensure the last-resolved-ptr will not referring back to |
| * the current ptr (t). |
| */ |
| if (btf_type_is_modifier(next_type)) { |
| const struct btf_type *resolved_type; |
| u32 resolved_type_id; |
| |
| resolved_type_id = next_type_id; |
| resolved_type = btf_type_id_resolve(btf, &resolved_type_id); |
| |
| if (btf_type_is_ptr(resolved_type) && |
| !env_type_is_resolve_sink(env, resolved_type) && |
| !env_type_is_resolved(env, resolved_type_id)) |
| return env_stack_push(env, resolved_type, |
| resolved_type_id); |
| } |
| |
| if (!btf_type_id_size(btf, &next_type_id, NULL)) { |
| if (env_type_is_resolved(env, next_type_id)) |
| next_type = btf_type_id_resolve(btf, &next_type_id); |
| |
| if (!btf_type_is_void(next_type) && |
| !btf_type_is_fwd(next_type) && |
| !btf_type_is_func_proto(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| } |
| |
| env_stack_pop_resolved(env, next_type_id, 0); |
| |
| return 0; |
| } |
| |
| static void btf_modifier_show(const struct btf *btf, |
| const struct btf_type *t, |
| u32 type_id, void *data, |
| u8 bits_offset, struct btf_show *show) |
| { |
| if (btf->resolved_ids) |
| t = btf_type_id_resolve(btf, &type_id); |
| else |
| t = btf_type_skip_modifiers(btf, type_id, NULL); |
| |
| btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
| } |
| |
| static void btf_var_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| t = btf_type_id_resolve(btf, &type_id); |
| |
| btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show); |
| } |
| |
| static void btf_ptr_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| void *safe_data; |
| |
| safe_data = btf_show_start_type(show, t, type_id, data); |
| if (!safe_data) |
| return; |
| |
| /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */ |
| if (show->flags & BTF_SHOW_PTR_RAW) |
| btf_show_type_value(show, "0x%px", *(void **)safe_data); |
| else |
| btf_show_type_value(show, "0x%p", *(void **)safe_data); |
| btf_show_end_type(show); |
| } |
| |
| static void btf_ref_type_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| btf_verifier_log(env, "type_id=%u", t->type); |
| } |
| |
| static struct btf_kind_operations modifier_ops = { |
| .check_meta = btf_ref_type_check_meta, |
| .resolve = btf_modifier_resolve, |
| .check_member = btf_modifier_check_member, |
| .check_kflag_member = btf_modifier_check_kflag_member, |
| .log_details = btf_ref_type_log, |
| .show = btf_modifier_show, |
| }; |
| |
| static struct btf_kind_operations ptr_ops = { |
| .check_meta = btf_ref_type_check_meta, |
| .resolve = btf_ptr_resolve, |
| .check_member = btf_ptr_check_member, |
| .check_kflag_member = btf_generic_check_kflag_member, |
| .log_details = btf_ref_type_log, |
| .show = btf_ptr_show, |
| }; |
| |
| static s32 btf_fwd_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (t->type) { |
| btf_verifier_log_type(env, t, "type != 0"); |
| return -EINVAL; |
| } |
| |
| /* fwd type must have a valid name */ |
| if (!t->name_off || |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return 0; |
| } |
| |
| static void btf_fwd_type_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); |
| } |
| |
| static struct btf_kind_operations fwd_ops = { |
| .check_meta = btf_fwd_check_meta, |
| .resolve = btf_df_resolve, |
| .check_member = btf_df_check_member, |
| .check_kflag_member = btf_df_check_kflag_member, |
| .log_details = btf_fwd_type_log, |
| .show = btf_df_show, |
| }; |
| |
| static int btf_array_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 struct_bits_off = member->offset; |
| u32 struct_size, bytes_offset; |
| u32 array_type_id, array_size; |
| struct btf *btf = env->btf; |
| |
| if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member is not byte aligned"); |
| return -EINVAL; |
| } |
| |
| array_type_id = member->type; |
| btf_type_id_size(btf, &array_type_id, &array_size); |
| struct_size = struct_type->size; |
| bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| if (struct_size - bytes_offset < array_size) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static s32 btf_array_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const struct btf_array *array = btf_type_array(t); |
| u32 meta_needed = sizeof(*array); |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| /* array type should not have a name */ |
| if (t->name_off) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| if (t->size) { |
| btf_verifier_log_type(env, t, "size != 0"); |
| return -EINVAL; |
| } |
| |
| /* Array elem type and index type cannot be in type void, |
| * so !array->type and !array->index_type are not allowed. |
| */ |
| if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { |
| btf_verifier_log_type(env, t, "Invalid elem"); |
| return -EINVAL; |
| } |
| |
| if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { |
| btf_verifier_log_type(env, t, "Invalid index"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return meta_needed; |
| } |
| |
| static int btf_array_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_array *array = btf_type_array(v->t); |
| const struct btf_type *elem_type, *index_type; |
| u32 elem_type_id, index_type_id; |
| struct btf *btf = env->btf; |
| u32 elem_size; |
| |
| /* Check array->index_type */ |
| index_type_id = array->index_type; |
| index_type = btf_type_by_id(btf, index_type_id); |
| if (btf_type_nosize_or_null(index_type) || |
| btf_type_is_resolve_source_only(index_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid index"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, index_type) && |
| !env_type_is_resolved(env, index_type_id)) |
| return env_stack_push(env, index_type, index_type_id); |
| |
| index_type = btf_type_id_size(btf, &index_type_id, NULL); |
| if (!index_type || !btf_type_is_int(index_type) || |
| !btf_type_int_is_regular(index_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid index"); |
| return -EINVAL; |
| } |
| |
| /* Check array->type */ |
| elem_type_id = array->type; |
| elem_type = btf_type_by_id(btf, elem_type_id); |
| if (btf_type_nosize_or_null(elem_type) || |
| btf_type_is_resolve_source_only(elem_type)) { |
| btf_verifier_log_type(env, v->t, |
| "Invalid elem"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, elem_type) && |
| !env_type_is_resolved(env, elem_type_id)) |
| return env_stack_push(env, elem_type, elem_type_id); |
| |
| elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); |
| if (!elem_type) { |
| btf_verifier_log_type(env, v->t, "Invalid elem"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid array of int"); |
| return -EINVAL; |
| } |
| |
| if (array->nelems && elem_size > U32_MAX / array->nelems) { |
| btf_verifier_log_type(env, v->t, |
| "Array size overflows U32_MAX"); |
| return -EINVAL; |
| } |
| |
| env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); |
| |
| return 0; |
| } |
| |
| static void btf_array_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| const struct btf_array *array = btf_type_array(t); |
| |
| btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", |
| array->type, array->index_type, array->nelems); |
| } |
| |
| static void __btf_array_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_array *array = btf_type_array(t); |
| const struct btf_kind_operations *elem_ops; |
| const struct btf_type *elem_type; |
| u32 i, elem_size = 0, elem_type_id; |
| u16 encoding = 0; |
| |
| elem_type_id = array->type; |
| elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL); |
| if (elem_type && btf_type_has_size(elem_type)) |
| elem_size = elem_type->size; |
| |
| if (elem_type && btf_type_is_int(elem_type)) { |
| u32 int_type = btf_type_int(elem_type); |
| |
| encoding = BTF_INT_ENCODING(int_type); |
| |
| /* |
| * BTF_INT_CHAR encoding never seems to be set for |
| * char arrays, so if size is 1 and element is |
| * printable as a char, we'll do that. |
| */ |
| if (elem_size == 1) |
| encoding = BTF_INT_CHAR; |
| } |
| |
| if (!btf_show_start_array_type(show, t, type_id, encoding, data)) |
| return; |
| |
| if (!elem_type) |
| goto out; |
| elem_ops = btf_type_ops(elem_type); |
| |
| for (i = 0; i < array->nelems; i++) { |
| |
| btf_show_start_array_member(show); |
| |
| elem_ops->show(btf, elem_type, elem_type_id, data, |
| bits_offset, show); |
| data += elem_size; |
| |
| btf_show_end_array_member(show); |
| |
| if (show->state.array_terminated) |
| break; |
| } |
| out: |
| btf_show_end_array_type(show); |
| } |
| |
| static void btf_array_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_member *m = show->state.member; |
| |
| /* |
| * First check if any members would be shown (are non-zero). |
| * See comments above "struct btf_show" definition for more |
| * details on how this works at a high-level. |
| */ |
| if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { |
| if (!show->state.depth_check) { |
| show->state.depth_check = show->state.depth + 1; |
| show->state.depth_to_show = 0; |
| } |
| __btf_array_show(btf, t, type_id, data, bits_offset, show); |
| show->state.member = m; |
| |
| if (show->state.depth_check != show->state.depth + 1) |
| return; |
| show->state.depth_check = 0; |
| |
| if (show->state.depth_to_show <= show->state.depth) |
| return; |
| /* |
| * Reaching here indicates we have recursed and found |
| * non-zero array member(s). |
| */ |
| } |
| __btf_array_show(btf, t, type_id, data, bits_offset, show); |
| } |
| |
| static struct btf_kind_operations array_ops = { |
| .check_meta = btf_array_check_meta, |
| .resolve = btf_array_resolve, |
| .check_member = btf_array_check_member, |
| .check_kflag_member = btf_generic_check_kflag_member, |
| .log_details = btf_array_log, |
| .show = btf_array_show, |
| }; |
| |
| static int btf_struct_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 struct_bits_off = member->offset; |
| u32 struct_size, bytes_offset; |
| |
| if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member is not byte aligned"); |
| return -EINVAL; |
| } |
| |
| struct_size = struct_type->size; |
| bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| if (struct_size - bytes_offset < member_type->size) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static s32 btf_struct_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; |
| const struct btf_member *member; |
| u32 meta_needed, last_offset; |
| struct btf *btf = env->btf; |
| u32 struct_size = t->size; |
| u32 offset; |
| u16 i; |
| |
| meta_needed = btf_type_vlen(t) * sizeof(*member); |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| /* struct type either no name or a valid one */ |
| if (t->name_off && |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| last_offset = 0; |
| for_each_member(i, t, member) { |
| if (!btf_name_offset_valid(btf, member->name_off)) { |
| btf_verifier_log_member(env, t, member, |
| "Invalid member name_offset:%u", |
| member->name_off); |
| return -EINVAL; |
| } |
| |
| /* struct member either no name or a valid one */ |
| if (member->name_off && |
| !btf_name_valid_identifier(btf, member->name_off)) { |
| btf_verifier_log_member(env, t, member, "Invalid name"); |
| return -EINVAL; |
| } |
| /* A member cannot be in type void */ |
| if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { |
| btf_verifier_log_member(env, t, member, |
| "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| offset = __btf_member_bit_offset(t, member); |
| if (is_union && offset) { |
| btf_verifier_log_member(env, t, member, |
| "Invalid member bits_offset"); |
| return -EINVAL; |
| } |
| |
| /* |
| * ">" instead of ">=" because the last member could be |
| * "char a[0];" |
| */ |
| if (last_offset > offset) { |
| btf_verifier_log_member(env, t, member, |
| "Invalid member bits_offset"); |
| return -EINVAL; |
| } |
| |
| if (BITS_ROUNDUP_BYTES(offset) > struct_size) { |
| btf_verifier_log_member(env, t, member, |
| "Member bits_offset exceeds its struct size"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_member(env, t, member, NULL); |
| last_offset = offset; |
| } |
| |
| return meta_needed; |
| } |
| |
| static int btf_struct_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_member *member; |
| int err; |
| u16 i; |
| |
| /* Before continue resolving the next_member, |
| * ensure the last member is indeed resolved to a |
| * type with size info. |
| */ |
| if (v->next_member) { |
| const struct btf_type *last_member_type; |
| const struct btf_member *last_member; |
| u32 last_member_type_id; |
| |
| last_member = btf_type_member(v->t) + v->next_member - 1; |
| last_member_type_id = last_member->type; |
| if (WARN_ON_ONCE(!env_type_is_resolved(env, |
| last_member_type_id))) |
| return -EINVAL; |
| |
| last_member_type = btf_type_by_id(env->btf, |
| last_member_type_id); |
| if (btf_type_kflag(v->t)) |
| err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, |
| last_member, |
| last_member_type); |
| else |
| err = btf_type_ops(last_member_type)->check_member(env, v->t, |
| last_member, |
| last_member_type); |
| if (err) |
| return err; |
| } |
| |
| for_each_member_from(i, v->next_member, v->t, member) { |
| u32 member_type_id = member->type; |
| const struct btf_type *member_type = btf_type_by_id(env->btf, |
| member_type_id); |
| |
| if (btf_type_nosize_or_null(member_type) || |
| btf_type_is_resolve_source_only(member_type)) { |
| btf_verifier_log_member(env, v->t, member, |
| "Invalid member"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, member_type) && |
| !env_type_is_resolved(env, member_type_id)) { |
| env_stack_set_next_member(env, i + 1); |
| return env_stack_push(env, member_type, member_type_id); |
| } |
| |
| if (btf_type_kflag(v->t)) |
| err = btf_type_ops(member_type)->check_kflag_member(env, v->t, |
| member, |
| member_type); |
| else |
| err = btf_type_ops(member_type)->check_member(env, v->t, |
| member, |
| member_type); |
| if (err) |
| return err; |
| } |
| |
| env_stack_pop_resolved(env, 0, 0); |
| |
| return 0; |
| } |
| |
| static void btf_struct_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
| } |
| |
| enum { |
| BTF_FIELD_IGNORE = 0, |
| BTF_FIELD_FOUND = 1, |
| }; |
| |
| struct btf_field_info { |
| enum btf_field_type type; |
| u32 off; |
| union { |
| struct { |
| u32 type_id; |
| } kptr; |
| struct { |
| const char *node_name; |
| u32 value_btf_id; |
| } graph_root; |
| }; |
| }; |
| |
| static int btf_find_struct(const struct btf *btf, const struct btf_type *t, |
| u32 off, int sz, enum btf_field_type field_type, |
| struct btf_field_info *info) |
| { |
| if (!__btf_type_is_struct(t)) |
| return BTF_FIELD_IGNORE; |
| if (t->size != sz) |
| return BTF_FIELD_IGNORE; |
| info->type = field_type; |
| info->off = off; |
| return BTF_FIELD_FOUND; |
| } |
| |
| static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, |
| u32 off, int sz, struct btf_field_info *info) |
| { |
| enum btf_field_type type; |
| u32 res_id; |
| |
| /* Permit modifiers on the pointer itself */ |
| if (btf_type_is_volatile(t)) |
| t = btf_type_by_id(btf, t->type); |
| /* For PTR, sz is always == 8 */ |
| if (!btf_type_is_ptr(t)) |
| return BTF_FIELD_IGNORE; |
| t = btf_type_by_id(btf, t->type); |
| |
| if (!btf_type_is_type_tag(t)) |
| return BTF_FIELD_IGNORE; |
| /* Reject extra tags */ |
| if (btf_type_is_type_tag(btf_type_by_id(btf, t->type))) |
| return -EINVAL; |
| if (!strcmp("kptr_untrusted", __btf_name_by_offset(btf, t->name_off))) |
| type = BPF_KPTR_UNREF; |
| else if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) |
| type = BPF_KPTR_REF; |
| else if (!strcmp("percpu_kptr", __btf_name_by_offset(btf, t->name_off))) |
| type = BPF_KPTR_PERCPU; |
| else |
| return -EINVAL; |
| |
| /* Get the base type */ |
| t = btf_type_skip_modifiers(btf, t->type, &res_id); |
| /* Only pointer to struct is allowed */ |
| if (!__btf_type_is_struct(t)) |
| return -EINVAL; |
| |
| info->type = type; |
| info->off = off; |
| info->kptr.type_id = res_id; |
| return BTF_FIELD_FOUND; |
| } |
| |
| int btf_find_next_decl_tag(const struct btf *btf, const struct btf_type *pt, |
| int comp_idx, const char *tag_key, int last_id) |
| { |
| int len = strlen(tag_key); |
| int i, n; |
| |
| for (i = last_id + 1, n = btf_nr_types(btf); i < n; i++) { |
| const struct btf_type *t = btf_type_by_id(btf, i); |
| |
| if (!btf_type_is_decl_tag(t)) |
| continue; |
| if (pt != btf_type_by_id(btf, t->type)) |
| continue; |
| if (btf_type_decl_tag(t)->component_idx != comp_idx) |
| continue; |
| if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len)) |
| continue; |
| return i; |
| } |
| return -ENOENT; |
| } |
| |
| const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt, |
| int comp_idx, const char *tag_key) |
| { |
| const char *value = NULL; |
| const struct btf_type *t; |
| int len, id; |
| |
| id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, 0); |
| if (id < 0) |
| return ERR_PTR(id); |
| |
| t = btf_type_by_id(btf, id); |
| len = strlen(tag_key); |
| value = __btf_name_by_offset(btf, t->name_off) + len; |
| |
| /* Prevent duplicate entries for same type */ |
| id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, id); |
| if (id >= 0) |
| return ERR_PTR(-EEXIST); |
| |
| return value; |
| } |
| |
| static int |
| btf_find_graph_root(const struct btf *btf, const struct btf_type *pt, |
| const struct btf_type *t, int comp_idx, u32 off, |
| int sz, struct btf_field_info *info, |
| enum btf_field_type head_type) |
| { |
| const char *node_field_name; |
| const char *value_type; |
| s32 id; |
| |
| if (!__btf_type_is_struct(t)) |
| return BTF_FIELD_IGNORE; |
| if (t->size != sz) |
| return BTF_FIELD_IGNORE; |
| value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:"); |
| if (IS_ERR(value_type)) |
| return -EINVAL; |
| node_field_name = strstr(value_type, ":"); |
| if (!node_field_name) |
| return -EINVAL; |
| value_type = kstrndup(value_type, node_field_name - value_type, GFP_KERNEL | __GFP_NOWARN); |
| if (!value_type) |
| return -ENOMEM; |
| id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT); |
| kfree(value_type); |
| if (id < 0) |
| return id; |
| node_field_name++; |
| if (str_is_empty(node_field_name)) |
| return -EINVAL; |
| info->type = head_type; |
| info->off = off; |
| info->graph_root.value_btf_id = id; |
| info->graph_root.node_name = node_field_name; |
| return BTF_FIELD_FOUND; |
| } |
| |
| #define field_mask_test_name(field_type, field_type_str) \ |
| if (field_mask & field_type && !strcmp(name, field_type_str)) { \ |
| type = field_type; \ |
| goto end; \ |
| } |
| |
| static int btf_get_field_type(const struct btf *btf, const struct btf_type *var_type, |
| u32 field_mask, u32 *seen_mask, |
| int *align, int *sz) |
| { |
| int type = 0; |
| const char *name = __btf_name_by_offset(btf, var_type->name_off); |
| |
| if (field_mask & BPF_SPIN_LOCK) { |
| if (!strcmp(name, "bpf_spin_lock")) { |
| if (*seen_mask & BPF_SPIN_LOCK) |
| return -E2BIG; |
| *seen_mask |= BPF_SPIN_LOCK; |
| type = BPF_SPIN_LOCK; |
| goto end; |
| } |
| } |
| if (field_mask & BPF_TIMER) { |
| if (!strcmp(name, "bpf_timer")) { |
| if (*seen_mask & BPF_TIMER) |
| return -E2BIG; |
| *seen_mask |= BPF_TIMER; |
| type = BPF_TIMER; |
| goto end; |
| } |
| } |
| if (field_mask & BPF_WORKQUEUE) { |
| if (!strcmp(name, "bpf_wq")) { |
| if (*seen_mask & BPF_WORKQUEUE) |
| return -E2BIG; |
| *seen_mask |= BPF_WORKQUEUE; |
| type = BPF_WORKQUEUE; |
| goto end; |
| } |
| } |
| field_mask_test_name(BPF_LIST_HEAD, "bpf_list_head"); |
| field_mask_test_name(BPF_LIST_NODE, "bpf_list_node"); |
| field_mask_test_name(BPF_RB_ROOT, "bpf_rb_root"); |
| field_mask_test_name(BPF_RB_NODE, "bpf_rb_node"); |
| field_mask_test_name(BPF_REFCOUNT, "bpf_refcount"); |
| |
| /* Only return BPF_KPTR when all other types with matchable names fail */ |
| if (field_mask & BPF_KPTR && !__btf_type_is_struct(var_type)) { |
| type = BPF_KPTR_REF; |
| goto end; |
| } |
| return 0; |
| end: |
| *sz = btf_field_type_size(type); |
| *align = btf_field_type_align(type); |
| return type; |
| } |
| |
| #undef field_mask_test_name |
| |
| /* Repeat a number of fields for a specified number of times. |
| * |
| * Copy the fields starting from the first field and repeat them for |
| * repeat_cnt times. The fields are repeated by adding the offset of each |
| * field with |
| * (i + 1) * elem_size |
| * where i is the repeat index and elem_size is the size of an element. |
| */ |
| static int btf_repeat_fields(struct btf_field_info *info, |
| u32 field_cnt, u32 repeat_cnt, u32 elem_size) |
| { |
| u32 i, j; |
| u32 cur; |
| |
| /* Ensure not repeating fields that should not be repeated. */ |
| for (i = 0; i < field_cnt; i++) { |
| switch (info[i].type) { |
| case BPF_KPTR_UNREF: |
| case BPF_KPTR_REF: |
| case BPF_KPTR_PERCPU: |
| case BPF_LIST_HEAD: |
| case BPF_RB_ROOT: |
| break; |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| cur = field_cnt; |
| for (i = 0; i < repeat_cnt; i++) { |
| memcpy(&info[cur], &info[0], field_cnt * sizeof(info[0])); |
| for (j = 0; j < field_cnt; j++) |
| info[cur++].off += (i + 1) * elem_size; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_find_struct_field(const struct btf *btf, |
| const struct btf_type *t, u32 field_mask, |
| struct btf_field_info *info, int info_cnt, |
| u32 level); |
| |
| /* Find special fields in the struct type of a field. |
| * |
| * This function is used to find fields of special types that is not a |
| * global variable or a direct field of a struct type. It also handles the |
| * repetition if it is the element type of an array. |
| */ |
| static int btf_find_nested_struct(const struct btf *btf, const struct btf_type *t, |
| u32 off, u32 nelems, |
| u32 field_mask, struct btf_field_info *info, |
| int info_cnt, u32 level) |
| { |
| int ret, err, i; |
| |
| level++; |
| if (level >= MAX_RESOLVE_DEPTH) |
| return -E2BIG; |
| |
| ret = btf_find_struct_field(btf, t, field_mask, info, info_cnt, level); |
| |
| if (ret <= 0) |
| return ret; |
| |
| /* Shift the offsets of the nested struct fields to the offsets |
| * related to the container. |
| */ |
| for (i = 0; i < ret; i++) |
| info[i].off += off; |
| |
| if (nelems > 1) { |
| err = btf_repeat_fields(info, ret, nelems - 1, t->size); |
| if (err == 0) |
| ret *= nelems; |
| else |
| ret = err; |
| } |
| |
| return ret; |
| } |
| |
| static int btf_find_field_one(const struct btf *btf, |
| const struct btf_type *var, |
| const struct btf_type *var_type, |
| int var_idx, |
| u32 off, u32 expected_size, |
| u32 field_mask, u32 *seen_mask, |
| struct btf_field_info *info, int info_cnt, |
| u32 level) |
| { |
| int ret, align, sz, field_type; |
| struct btf_field_info tmp; |
| const struct btf_array *array; |
| u32 i, nelems = 1; |
| |
| /* Walk into array types to find the element type and the number of |
| * elements in the (flattened) array. |
| */ |
| for (i = 0; i < MAX_RESOLVE_DEPTH && btf_type_is_array(var_type); i++) { |
| array = btf_array(var_type); |
| nelems *= array->nelems; |
| var_type = btf_type_by_id(btf, array->type); |
| } |
| if (i == MAX_RESOLVE_DEPTH) |
| return -E2BIG; |
| if (nelems == 0) |
| return 0; |
| |
| field_type = btf_get_field_type(btf, var_type, |
| field_mask, seen_mask, &align, &sz); |
| /* Look into variables of struct types */ |
| if (!field_type && __btf_type_is_struct(var_type)) { |
| sz = var_type->size; |
| if (expected_size && expected_size != sz * nelems) |
| return 0; |
| ret = btf_find_nested_struct(btf, var_type, off, nelems, field_mask, |
| &info[0], info_cnt, level); |
| return ret; |
| } |
| |
| if (field_type == 0) |
| return 0; |
| if (field_type < 0) |
| return field_type; |
| |
| if (expected_size && expected_size != sz * nelems) |
| return 0; |
| if (off % align) |
| return 0; |
| |
| switch (field_type) { |
| case BPF_SPIN_LOCK: |
| case BPF_TIMER: |
| case BPF_WORKQUEUE: |
| case BPF_LIST_NODE: |
| case BPF_RB_NODE: |
| case BPF_REFCOUNT: |
| ret = btf_find_struct(btf, var_type, off, sz, field_type, |
| info_cnt ? &info[0] : &tmp); |
| if (ret < 0) |
| return ret; |
| break; |
| case BPF_KPTR_UNREF: |
| case BPF_KPTR_REF: |
| case BPF_KPTR_PERCPU: |
| ret = btf_find_kptr(btf, var_type, off, sz, |
| info_cnt ? &info[0] : &tmp); |
| if (ret < 0) |
| return ret; |
| break; |
| case BPF_LIST_HEAD: |
| case BPF_RB_ROOT: |
| ret = btf_find_graph_root(btf, var, var_type, |
| var_idx, off, sz, |
| info_cnt ? &info[0] : &tmp, |
| field_type); |
| if (ret < 0) |
| return ret; |
| break; |
| default: |
| return -EFAULT; |
| } |
| |
| if (ret == BTF_FIELD_IGNORE) |
| return 0; |
| if (nelems > info_cnt) |
| return -E2BIG; |
| if (nelems > 1) { |
| ret = btf_repeat_fields(info, 1, nelems - 1, sz); |
| if (ret < 0) |
| return ret; |
| } |
| return nelems; |
| } |
| |
| static int btf_find_struct_field(const struct btf *btf, |
| const struct btf_type *t, u32 field_mask, |
| struct btf_field_info *info, int info_cnt, |
| u32 level) |
| { |
| int ret, idx = 0; |
| const struct btf_member *member; |
| u32 i, off, seen_mask = 0; |
| |
| for_each_member(i, t, member) { |
| const struct btf_type *member_type = btf_type_by_id(btf, |
| member->type); |
| |
| off = __btf_member_bit_offset(t, member); |
| if (off % 8) |
| /* valid C code cannot generate such BTF */ |
| return -EINVAL; |
| off /= 8; |
| |
| ret = btf_find_field_one(btf, t, member_type, i, |
| off, 0, |
| field_mask, &seen_mask, |
| &info[idx], info_cnt - idx, level); |
| if (ret < 0) |
| return ret; |
| idx += ret; |
| } |
| return idx; |
| } |
| |
| static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, |
| u32 field_mask, struct btf_field_info *info, |
| int info_cnt, u32 level) |
| { |
| int ret, idx = 0; |
| const struct btf_var_secinfo *vsi; |
| u32 i, off, seen_mask = 0; |
| |
| for_each_vsi(i, t, vsi) { |
| const struct btf_type *var = btf_type_by_id(btf, vsi->type); |
| const struct btf_type *var_type = btf_type_by_id(btf, var->type); |
| |
| off = vsi->offset; |
| ret = btf_find_field_one(btf, var, var_type, -1, off, vsi->size, |
| field_mask, &seen_mask, |
| &info[idx], info_cnt - idx, |
| level); |
| if (ret < 0) |
| return ret; |
| idx += ret; |
| } |
| return idx; |
| } |
| |
| static int btf_find_field(const struct btf *btf, const struct btf_type *t, |
| u32 field_mask, struct btf_field_info *info, |
| int info_cnt) |
| { |
| if (__btf_type_is_struct(t)) |
| return btf_find_struct_field(btf, t, field_mask, info, info_cnt, 0); |
| else if (btf_type_is_datasec(t)) |
| return btf_find_datasec_var(btf, t, field_mask, info, info_cnt, 0); |
| return -EINVAL; |
| } |
| |
| /* Callers have to ensure the life cycle of btf if it is program BTF */ |
| static int btf_parse_kptr(const struct btf *btf, struct btf_field *field, |
| struct btf_field_info *info) |
| { |
| struct module *mod = NULL; |
| const struct btf_type *t; |
| /* If a matching btf type is found in kernel or module BTFs, kptr_ref |
| * is that BTF, otherwise it's program BTF |
| */ |
| struct btf *kptr_btf; |
| int ret; |
| s32 id; |
| |
| /* Find type in map BTF, and use it to look up the matching type |
| * in vmlinux or module BTFs, by name and kind. |
| */ |
| t = btf_type_by_id(btf, info->kptr.type_id); |
| id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info), |
| &kptr_btf); |
| if (id == -ENOENT) { |
| /* btf_parse_kptr should only be called w/ btf = program BTF */ |
| WARN_ON_ONCE(btf_is_kernel(btf)); |
| |
| /* Type exists only in program BTF. Assume that it's a MEM_ALLOC |
| * kptr allocated via bpf_obj_new |
| */ |
| field->kptr.dtor = NULL; |
| id = info->kptr.type_id; |
| kptr_btf = (struct btf *)btf; |
| goto found_dtor; |
| } |
| if (id < 0) |
| return id; |
| |
| /* Find and stash the function pointer for the destruction function that |
| * needs to be eventually invoked from the map free path. |
| */ |
| if (info->type == BPF_KPTR_REF) { |
| const struct btf_type *dtor_func; |
| const char *dtor_func_name; |
| unsigned long addr; |
| s32 dtor_btf_id; |
| |
| /* This call also serves as a whitelist of allowed objects that |
| * can be used as a referenced pointer and be stored in a map at |
| * the same time. |
| */ |
| dtor_btf_id = btf_find_dtor_kfunc(kptr_btf, id); |
| if (dtor_btf_id < 0) { |
| ret = dtor_btf_id; |
| goto end_btf; |
| } |
| |
| dtor_func = btf_type_by_id(kptr_btf, dtor_btf_id); |
| if (!dtor_func) { |
| ret = -ENOENT; |
| goto end_btf; |
| } |
| |
| if (btf_is_module(kptr_btf)) { |
| mod = btf_try_get_module(kptr_btf); |
| if (!mod) { |
| ret = -ENXIO; |
| goto end_btf; |
| } |
| } |
| |
| /* We already verified dtor_func to be btf_type_is_func |
| * in register_btf_id_dtor_kfuncs. |
| */ |
| dtor_func_name = __btf_name_by_offset(kptr_btf, dtor_func->name_off); |
| addr = kallsyms_lookup_name(dtor_func_name); |
| if (!addr) { |
| ret = -EINVAL; |
| goto end_mod; |
| } |
| field->kptr.dtor = (void *)addr; |
| } |
| |
| found_dtor: |
| field->kptr.btf_id = id; |
| field->kptr.btf = kptr_btf; |
| field->kptr.module = mod; |
| return 0; |
| end_mod: |
| module_put(mod); |
| end_btf: |
| btf_put(kptr_btf); |
| return ret; |
| } |
| |
| static int btf_parse_graph_root(const struct btf *btf, |
| struct btf_field *field, |
| struct btf_field_info *info, |
| const char *node_type_name, |
| size_t node_type_align) |
| { |
| const struct btf_type *t, *n = NULL; |
| const struct btf_member *member; |
| u32 offset; |
| int i; |
| |
| t = btf_type_by_id(btf, info->graph_root.value_btf_id); |
| /* We've already checked that value_btf_id is a struct type. We |
| * just need to figure out the offset of the list_node, and |
| * verify its type. |
| */ |
| for_each_member(i, t, member) { |
| if (strcmp(info->graph_root.node_name, |
| __btf_name_by_offset(btf, member->name_off))) |
| continue; |
| /* Invalid BTF, two members with same name */ |
| if (n) |
| return -EINVAL; |
| n = btf_type_by_id(btf, member->type); |
| if (!__btf_type_is_struct(n)) |
| return -EINVAL; |
| if (strcmp(node_type_name, __btf_name_by_offset(btf, n->name_off))) |
| return -EINVAL; |
| offset = __btf_member_bit_offset(n, member); |
| if (offset % 8) |
| return -EINVAL; |
| offset /= 8; |
| if (offset % node_type_align) |
| return -EINVAL; |
| |
| field->graph_root.btf = (struct btf *)btf; |
| field->graph_root.value_btf_id = info->graph_root.value_btf_id; |
| field->graph_root.node_offset = offset; |
| } |
| if (!n) |
| return -ENOENT; |
| return 0; |
| } |
| |
| static int btf_parse_list_head(const struct btf *btf, struct btf_field *field, |
| struct btf_field_info *info) |
| { |
| return btf_parse_graph_root(btf, field, info, "bpf_list_node", |
| __alignof__(struct bpf_list_node)); |
| } |
| |
| static int btf_parse_rb_root(const struct btf *btf, struct btf_field *field, |
| struct btf_field_info *info) |
| { |
| return btf_parse_graph_root(btf, field, info, "bpf_rb_node", |
| __alignof__(struct bpf_rb_node)); |
| } |
| |
| static int btf_field_cmp(const void *_a, const void *_b, const void *priv) |
| { |
| const struct btf_field *a = (const struct btf_field *)_a; |
| const struct btf_field *b = (const struct btf_field *)_b; |
| |
| if (a->offset < b->offset) |
| return -1; |
| else if (a->offset > b->offset) |
| return 1; |
| return 0; |
| } |
| |
| struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t, |
| u32 field_mask, u32 value_size) |
| { |
| struct btf_field_info info_arr[BTF_FIELDS_MAX]; |
| u32 next_off = 0, field_type_size; |
| struct btf_record *rec; |
| int ret, i, cnt; |
| |
| ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr)); |
| if (ret < 0) |
| return ERR_PTR(ret); |
| if (!ret) |
| return NULL; |
| |
| cnt = ret; |
| /* This needs to be kzalloc to zero out padding and unused fields, see |
| * comment in btf_record_equal. |
| */ |
| rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN); |
| if (!rec) |
| return ERR_PTR(-ENOMEM); |
| |
| rec->spin_lock_off = -EINVAL; |
| rec->timer_off = -EINVAL; |
| rec->wq_off = -EINVAL; |
| rec->refcount_off = -EINVAL; |
| for (i = 0; i < cnt; i++) { |
| field_type_size = btf_field_type_size(info_arr[i].type); |
| if (info_arr[i].off + field_type_size > value_size) { |
| WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size); |
| ret = -EFAULT; |
| goto end; |
| } |
| if (info_arr[i].off < next_off) { |
| ret = -EEXIST; |
| goto end; |
| } |
| next_off = info_arr[i].off + field_type_size; |
| |
| rec->field_mask |= info_arr[i].type; |
| rec->fields[i].offset = info_arr[i].off; |
| rec->fields[i].type = info_arr[i].type; |
| rec->fields[i].size = field_type_size; |
| |
| switch (info_arr[i].type) { |
| case BPF_SPIN_LOCK: |
| WARN_ON_ONCE(rec->spin_lock_off >= 0); |
| /* Cache offset for faster lookup at runtime */ |
| rec->spin_lock_off = rec->fields[i].offset; |
| break; |
| case BPF_TIMER: |
| WARN_ON_ONCE(rec->timer_off >= 0); |
| /* Cache offset for faster lookup at runtime */ |
| rec->timer_off = rec->fields[i].offset; |
| break; |
| case BPF_WORKQUEUE: |
| WARN_ON_ONCE(rec->wq_off >= 0); |
| /* Cache offset for faster lookup at runtime */ |
| rec->wq_off = rec->fields[i].offset; |
| break; |
| case BPF_REFCOUNT: |
| WARN_ON_ONCE(rec->refcount_off >= 0); |
| /* Cache offset for faster lookup at runtime */ |
| rec->refcount_off = rec->fields[i].offset; |
| break; |
| case BPF_KPTR_UNREF: |
| case BPF_KPTR_REF: |
| case BPF_KPTR_PERCPU: |
| ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); |
| if (ret < 0) |
| goto end; |
| break; |
| case BPF_LIST_HEAD: |
| ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]); |
| if (ret < 0) |
| goto end; |
| break; |
| case BPF_RB_ROOT: |
| ret = btf_parse_rb_root(btf, &rec->fields[i], &info_arr[i]); |
| if (ret < 0) |
| goto end; |
| break; |
| case BPF_LIST_NODE: |
| case BPF_RB_NODE: |
| break; |
| default: |
| ret = -EFAULT; |
| goto end; |
| } |
| rec->cnt++; |
| } |
| |
| /* bpf_{list_head, rb_node} require bpf_spin_lock */ |
| if ((btf_record_has_field(rec, BPF_LIST_HEAD) || |
| btf_record_has_field(rec, BPF_RB_ROOT)) && rec->spin_lock_off < 0) { |
| ret = -EINVAL; |
| goto end; |
| } |
| |
| if (rec->refcount_off < 0 && |
| btf_record_has_field(rec, BPF_LIST_NODE) && |
| btf_record_has_field(rec, BPF_RB_NODE)) { |
| ret = -EINVAL; |
| goto end; |
| } |
| |
| sort_r(rec->fields, rec->cnt, sizeof(struct btf_field), btf_field_cmp, |
| NULL, rec); |
| |
| return rec; |
| end: |
| btf_record_free(rec); |
| return ERR_PTR(ret); |
| } |
| |
| int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec) |
| { |
| int i; |
| |
| /* There are three types that signify ownership of some other type: |
| * kptr_ref, bpf_list_head, bpf_rb_root. |
| * kptr_ref only supports storing kernel types, which can't store |
| * references to program allocated local types. |
| * |
| * Hence we only need to ensure that bpf_{list_head,rb_root} ownership |
| * does not form cycles. |
| */ |
| if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & BPF_GRAPH_ROOT)) |
| return 0; |
| for (i = 0; i < rec->cnt; i++) { |
| struct btf_struct_meta *meta; |
| u32 btf_id; |
| |
| if (!(rec->fields[i].type & BPF_GRAPH_ROOT)) |
| continue; |
| btf_id = rec->fields[i].graph_root.value_btf_id; |
| meta = btf_find_struct_meta(btf, btf_id); |
| if (!meta) |
| return -EFAULT; |
| rec->fields[i].graph_root.value_rec = meta->record; |
| |
| /* We need to set value_rec for all root types, but no need |
| * to check ownership cycle for a type unless it's also a |
| * node type. |
| */ |
| if (!(rec->field_mask & BPF_GRAPH_NODE)) |
| continue; |
| |
| /* We need to ensure ownership acyclicity among all types. The |
| * proper way to do it would be to topologically sort all BTF |
| * IDs based on the ownership edges, since there can be multiple |
| * bpf_{list_head,rb_node} in a type. Instead, we use the |
| * following resaoning: |
| * |
| * - A type can only be owned by another type in user BTF if it |
| * has a bpf_{list,rb}_node. Let's call these node types. |
| * - A type can only _own_ another type in user BTF if it has a |
| * bpf_{list_head,rb_root}. Let's call these root types. |
| * |
| * We ensure that if a type is both a root and node, its |
| * element types cannot be root types. |
| * |
| * To ensure acyclicity: |
| * |
| * When A is an root type but not a node, its ownership |
| * chain can be: |
| * A -> B -> C |
| * Where: |
| * - A is an root, e.g. has bpf_rb_root. |
| * - B is both a root and node, e.g. has bpf_rb_node and |
| * bpf_list_head. |
| * - C is only an root, e.g. has bpf_list_node |
| * |
| * When A is both a root and node, some other type already |
| * owns it in the BTF domain, hence it can not own |
| * another root type through any of the ownership edges. |
| * A -> B |
| * Where: |
| * - A is both an root and node. |
| * - B is only an node. |
| */ |
| if (meta->record->field_mask & BPF_GRAPH_ROOT) |
| return -ELOOP; |
| } |
| return 0; |
| } |
| |
| static void __btf_struct_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_member *member; |
| void *safe_data; |
| u32 i; |
| |
| safe_data = btf_show_start_struct_type(show, t, type_id, data); |
| if (!safe_data) |
| return; |
| |
| for_each_member(i, t, member) { |
| const struct btf_type *member_type = btf_type_by_id(btf, |
| member->type); |
| const struct btf_kind_operations *ops; |
| u32 member_offset, bitfield_size; |
| u32 bytes_offset; |
| u8 bits8_offset; |
| |
| btf_show_start_member(show, member); |
| |
| member_offset = __btf_member_bit_offset(t, member); |
| bitfield_size = __btf_member_bitfield_size(t, member); |
| bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); |
| bits8_offset = BITS_PER_BYTE_MASKED(member_offset); |
| if (bitfield_size) { |
| safe_data = btf_show_start_type(show, member_type, |
| member->type, |
| data + bytes_offset); |
| if (safe_data) |
| btf_bitfield_show(safe_data, |
| bits8_offset, |
| bitfield_size, show); |
| btf_show_end_type(show); |
| } else { |
| ops = btf_type_ops(member_type); |
| ops->show(btf, member_type, member->type, |
| data + bytes_offset, bits8_offset, show); |
| } |
| |
| btf_show_end_member(show); |
| } |
| |
| btf_show_end_struct_type(show); |
| } |
| |
| static void btf_struct_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_member *m = show->state.member; |
| |
| /* |
| * First check if any members would be shown (are non-zero). |
| * See comments above "struct btf_show" definition for more |
| * details on how this works at a high-level. |
| */ |
| if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) { |
| if (!show->state.depth_check) { |
| show->state.depth_check = show->state.depth + 1; |
| show->state.depth_to_show = 0; |
| } |
| __btf_struct_show(btf, t, type_id, data, bits_offset, show); |
| /* Restore saved member data here */ |
| show->state.member = m; |
| if (show->state.depth_check != show->state.depth + 1) |
| return; |
| show->state.depth_check = 0; |
| |
| if (show->state.depth_to_show <= show->state.depth) |
| return; |
| /* |
| * Reaching here indicates we have recursed and found |
| * non-zero child values. |
| */ |
| } |
| |
| __btf_struct_show(btf, t, type_id, data, bits_offset, show); |
| } |
| |
| static struct btf_kind_operations struct_ops = { |
| .check_meta = btf_struct_check_meta, |
| .resolve = btf_struct_resolve, |
| .check_member = btf_struct_check_member, |
| .check_kflag_member = btf_generic_check_kflag_member, |
| .log_details = btf_struct_log, |
| .show = btf_struct_show, |
| }; |
| |
| static int btf_enum_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 struct_bits_off = member->offset; |
| u32 struct_size, bytes_offset; |
| |
| if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member is not byte aligned"); |
| return -EINVAL; |
| } |
| |
| struct_size = struct_type->size; |
| bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); |
| if (struct_size - bytes_offset < member_type->size) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_enum_check_kflag_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u32 struct_bits_off, nr_bits, bytes_end, struct_size; |
| u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; |
| |
| struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); |
| nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); |
| if (!nr_bits) { |
| if (BITS_PER_BYTE_MASKED(struct_bits_off)) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member is not byte aligned"); |
| return -EINVAL; |
| } |
| |
| nr_bits = int_bitsize; |
| } else if (nr_bits > int_bitsize) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Invalid member bitfield_size"); |
| return -EINVAL; |
| } |
| |
| struct_size = struct_type->size; |
| bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); |
| if (struct_size < bytes_end) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static s32 btf_enum_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const struct btf_enum *enums = btf_type_enum(t); |
| struct btf *btf = env->btf; |
| const char *fmt_str; |
| u16 i, nr_enums; |
| u32 meta_needed; |
| |
| nr_enums = btf_type_vlen(t); |
| meta_needed = nr_enums * sizeof(*enums); |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| if (t->size > 8 || !is_power_of_2(t->size)) { |
| btf_verifier_log_type(env, t, "Unexpected size"); |
| return -EINVAL; |
| } |
| |
| /* enum type either no name or a valid one */ |
| if (t->name_off && |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| for (i = 0; i < nr_enums; i++) { |
| if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
| btf_verifier_log(env, "\tInvalid name_offset:%u", |
| enums[i].name_off); |
| return -EINVAL; |
| } |
| |
| /* enum member must have a valid name */ |
| if (!enums[i].name_off || |
| !btf_name_valid_identifier(btf, enums[i].name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| if (env->log.level == BPF_LOG_KERNEL) |
| continue; |
| fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n"; |
| btf_verifier_log(env, fmt_str, |
| __btf_name_by_offset(btf, enums[i].name_off), |
| enums[i].val); |
| } |
| |
| return meta_needed; |
| } |
| |
| static void btf_enum_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
| } |
| |
| static void btf_enum_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_enum *enums = btf_type_enum(t); |
| u32 i, nr_enums = btf_type_vlen(t); |
| void *safe_data; |
| int v; |
| |
| safe_data = btf_show_start_type(show, t, type_id, data); |
| if (!safe_data) |
| return; |
| |
| v = *(int *)safe_data; |
| |
| for (i = 0; i < nr_enums; i++) { |
| if (v != enums[i].val) |
| continue; |
| |
| btf_show_type_value(show, "%s", |
| __btf_name_by_offset(btf, |
| enums[i].name_off)); |
| |
| btf_show_end_type(show); |
| return; |
| } |
| |
| if (btf_type_kflag(t)) |
| btf_show_type_value(show, "%d", v); |
| else |
| btf_show_type_value(show, "%u", v); |
| btf_show_end_type(show); |
| } |
| |
| static struct btf_kind_operations enum_ops = { |
| .check_meta = btf_enum_check_meta, |
| .resolve = btf_df_resolve, |
| .check_member = btf_enum_check_member, |
| .check_kflag_member = btf_enum_check_kflag_member, |
| .log_details = btf_enum_log, |
| .show = btf_enum_show, |
| }; |
| |
| static s32 btf_enum64_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const struct btf_enum64 *enums = btf_type_enum64(t); |
| struct btf *btf = env->btf; |
| const char *fmt_str; |
| u16 i, nr_enums; |
| u32 meta_needed; |
| |
| nr_enums = btf_type_vlen(t); |
| meta_needed = nr_enums * sizeof(*enums); |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| if (t->size > 8 || !is_power_of_2(t->size)) { |
| btf_verifier_log_type(env, t, "Unexpected size"); |
| return -EINVAL; |
| } |
| |
| /* enum type either no name or a valid one */ |
| if (t->name_off && |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| for (i = 0; i < nr_enums; i++) { |
| if (!btf_name_offset_valid(btf, enums[i].name_off)) { |
| btf_verifier_log(env, "\tInvalid name_offset:%u", |
| enums[i].name_off); |
| return -EINVAL; |
| } |
| |
| /* enum member must have a valid name */ |
| if (!enums[i].name_off || |
| !btf_name_valid_identifier(btf, enums[i].name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| if (env->log.level == BPF_LOG_KERNEL) |
| continue; |
| |
| fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n"; |
| btf_verifier_log(env, fmt_str, |
| __btf_name_by_offset(btf, enums[i].name_off), |
| btf_enum64_value(enums + i)); |
| } |
| |
| return meta_needed; |
| } |
| |
| static void btf_enum64_show(const struct btf *btf, const struct btf_type *t, |
| u32 type_id, void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_enum64 *enums = btf_type_enum64(t); |
| u32 i, nr_enums = btf_type_vlen(t); |
| void *safe_data; |
| s64 v; |
| |
| safe_data = btf_show_start_type(show, t, type_id, data); |
| if (!safe_data) |
| return; |
| |
| v = *(u64 *)safe_data; |
| |
| for (i = 0; i < nr_enums; i++) { |
| if (v != btf_enum64_value(enums + i)) |
| continue; |
| |
| btf_show_type_value(show, "%s", |
| __btf_name_by_offset(btf, |
| enums[i].name_off)); |
| |
| btf_show_end_type(show); |
| return; |
| } |
| |
| if (btf_type_kflag(t)) |
| btf_show_type_value(show, "%lld", v); |
| else |
| btf_show_type_value(show, "%llu", v); |
| btf_show_end_type(show); |
| } |
| |
| static struct btf_kind_operations enum64_ops = { |
| .check_meta = btf_enum64_check_meta, |
| .resolve = btf_df_resolve, |
| .check_member = btf_enum_check_member, |
| .check_kflag_member = btf_enum_check_kflag_member, |
| .log_details = btf_enum_log, |
| .show = btf_enum64_show, |
| }; |
| |
| static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| if (t->name_off) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return meta_needed; |
| } |
| |
| static void btf_func_proto_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| const struct btf_param *args = (const struct btf_param *)(t + 1); |
| u16 nr_args = btf_type_vlen(t), i; |
| |
| btf_verifier_log(env, "return=%u args=(", t->type); |
| if (!nr_args) { |
| btf_verifier_log(env, "void"); |
| goto done; |
| } |
| |
| if (nr_args == 1 && !args[0].type) { |
| /* Only one vararg */ |
| btf_verifier_log(env, "vararg"); |
| goto done; |
| } |
| |
| btf_verifier_log(env, "%u %s", args[0].type, |
| __btf_name_by_offset(env->btf, |
| args[0].name_off)); |
| for (i = 1; i < nr_args - 1; i++) |
| btf_verifier_log(env, ", %u %s", args[i].type, |
| __btf_name_by_offset(env->btf, |
| args[i].name_off)); |
| |
| if (nr_args > 1) { |
| const struct btf_param *last_arg = &args[nr_args - 1]; |
| |
| if (last_arg->type) |
| btf_verifier_log(env, ", %u %s", last_arg->type, |
| __btf_name_by_offset(env->btf, |
| last_arg->name_off)); |
| else |
| btf_verifier_log(env, ", vararg"); |
| } |
| |
| done: |
| btf_verifier_log(env, ")"); |
| } |
| |
| static struct btf_kind_operations func_proto_ops = { |
| .check_meta = btf_func_proto_check_meta, |
| .resolve = btf_df_resolve, |
| /* |
| * BTF_KIND_FUNC_PROTO cannot be directly referred by |
| * a struct's member. |
| * |
| * It should be a function pointer instead. |
| * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) |
| * |
| * Hence, there is no btf_func_check_member(). |
| */ |
| .check_member = btf_df_check_member, |
| .check_kflag_member = btf_df_check_kflag_member, |
| .log_details = btf_func_proto_log, |
| .show = btf_df_show, |
| }; |
| |
| static s32 btf_func_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| if (!t->name_off || |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) { |
| btf_verifier_log_type(env, t, "Invalid func linkage"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return 0; |
| } |
| |
| static int btf_func_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_type *t = v->t; |
| u32 next_type_id = t->type; |
| int err; |
| |
| err = btf_func_check(env, t); |
| if (err) |
| return err; |
| |
| env_stack_pop_resolved(env, next_type_id, 0); |
| return 0; |
| } |
| |
| static struct btf_kind_operations func_ops = { |
| .check_meta = btf_func_check_meta, |
| .resolve = btf_func_resolve, |
| .check_member = btf_df_check_member, |
| .check_kflag_member = btf_df_check_kflag_member, |
| .log_details = btf_ref_type_log, |
| .show = btf_df_show, |
| }; |
| |
| static s32 btf_var_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const struct btf_var *var; |
| u32 meta_needed = sizeof(*var); |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| if (!t->name_off || |
| !btf_name_valid_identifier(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| /* A var cannot be in type void */ |
| if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { |
| btf_verifier_log_type(env, t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| var = btf_type_var(t); |
| if (var->linkage != BTF_VAR_STATIC && |
| var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { |
| btf_verifier_log_type(env, t, "Linkage not supported"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return meta_needed; |
| } |
| |
| static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) |
| { |
| const struct btf_var *var = btf_type_var(t); |
| |
| btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); |
| } |
| |
| static const struct btf_kind_operations var_ops = { |
| .check_meta = btf_var_check_meta, |
| .resolve = btf_var_resolve, |
| .check_member = btf_df_check_member, |
| .check_kflag_member = btf_df_check_kflag_member, |
| .log_details = btf_var_log, |
| .show = btf_var_show, |
| }; |
| |
| static s32 btf_datasec_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const struct btf_var_secinfo *vsi; |
| u64 last_vsi_end_off = 0, sum = 0; |
| u32 i, meta_needed; |
| |
| meta_needed = btf_type_vlen(t) * sizeof(*vsi); |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| if (!t->size) { |
| btf_verifier_log_type(env, t, "size == 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| if (!t->name_off || |
| !btf_name_valid_section(env->btf, t->name_off)) { |
| btf_verifier_log_type(env, t, "Invalid name"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| for_each_vsi(i, t, vsi) { |
| /* A var cannot be in type void */ |
| if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { |
| btf_verifier_log_vsi(env, t, vsi, |
| "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { |
| btf_verifier_log_vsi(env, t, vsi, |
| "Invalid offset"); |
| return -EINVAL; |
| } |
| |
| if (!vsi->size || vsi->size > t->size) { |
| btf_verifier_log_vsi(env, t, vsi, |
| "Invalid size"); |
| return -EINVAL; |
| } |
| |
| last_vsi_end_off = vsi->offset + vsi->size; |
| if (last_vsi_end_off > t->size) { |
| btf_verifier_log_vsi(env, t, vsi, |
| "Invalid offset+size"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_vsi(env, t, vsi, NULL); |
| sum += vsi->size; |
| } |
| |
| if (t->size < sum) { |
| btf_verifier_log_type(env, t, "Invalid btf_info size"); |
| return -EINVAL; |
| } |
| |
| return meta_needed; |
| } |
| |
| static int btf_datasec_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_var_secinfo *vsi; |
| struct btf *btf = env->btf; |
| u16 i; |
| |
| env->resolve_mode = RESOLVE_TBD; |
| for_each_vsi_from(i, v->next_member, v->t, vsi) { |
| u32 var_type_id = vsi->type, type_id, type_size = 0; |
| const struct btf_type *var_type = btf_type_by_id(env->btf, |
| var_type_id); |
| if (!var_type || !btf_type_is_var(var_type)) { |
| btf_verifier_log_vsi(env, v->t, vsi, |
| "Not a VAR kind member"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, var_type) && |
| !env_type_is_resolved(env, var_type_id)) { |
| env_stack_set_next_member(env, i + 1); |
| return env_stack_push(env, var_type, var_type_id); |
| } |
| |
| type_id = var_type->type; |
| if (!btf_type_id_size(btf, &type_id, &type_size)) { |
| btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); |
| return -EINVAL; |
| } |
| |
| if (vsi->size < type_size) { |
| btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); |
| return -EINVAL; |
| } |
| } |
| |
| env_stack_pop_resolved(env, 0, 0); |
| return 0; |
| } |
| |
| static void btf_datasec_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); |
| } |
| |
| static void btf_datasec_show(const struct btf *btf, |
| const struct btf_type *t, u32 type_id, |
| void *data, u8 bits_offset, |
| struct btf_show *show) |
| { |
| const struct btf_var_secinfo *vsi; |
| const struct btf_type *var; |
| u32 i; |
| |
| if (!btf_show_start_type(show, t, type_id, data)) |
| return; |
| |
| btf_show_type_value(show, "section (\"%s\") = {", |
| __btf_name_by_offset(btf, t->name_off)); |
| for_each_vsi(i, t, vsi) { |
| var = btf_type_by_id(btf, vsi->type); |
| if (i) |
| btf_show(show, ","); |
| btf_type_ops(var)->show(btf, var, vsi->type, |
| data + vsi->offset, bits_offset, show); |
| } |
| btf_show_end_type(show); |
| } |
| |
| static const struct btf_kind_operations datasec_ops = { |
| .check_meta = btf_datasec_check_meta, |
| .resolve = btf_datasec_resolve, |
| .check_member = btf_df_check_member, |
| .check_kflag_member = btf_df_check_kflag_member, |
| .log_details = btf_datasec_log, |
| .show = btf_datasec_show, |
| }; |
| |
| static s32 btf_float_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && |
| t->size != 16) { |
| btf_verifier_log_type(env, t, "Invalid type_size"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return 0; |
| } |
| |
| static int btf_float_check_member(struct btf_verifier_env *env, |
| const struct btf_type *struct_type, |
| const struct btf_member *member, |
| const struct btf_type *member_type) |
| { |
| u64 start_offset_bytes; |
| u64 end_offset_bytes; |
| u64 misalign_bits; |
| u64 align_bytes; |
| u64 align_bits; |
| |
| /* Different architectures have different alignment requirements, so |
| * here we check only for the reasonable minimum. This way we ensure |
| * that types after CO-RE can pass the kernel BTF verifier. |
| */ |
| align_bytes = min_t(u64, sizeof(void *), member_type->size); |
| align_bits = align_bytes * BITS_PER_BYTE; |
| div64_u64_rem(member->offset, align_bits, &misalign_bits); |
| if (misalign_bits) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member is not properly aligned"); |
| return -EINVAL; |
| } |
| |
| start_offset_bytes = member->offset / BITS_PER_BYTE; |
| end_offset_bytes = start_offset_bytes + member_type->size; |
| if (end_offset_bytes > struct_type->size) { |
| btf_verifier_log_member(env, struct_type, member, |
| "Member exceeds struct_size"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static void btf_float_log(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| btf_verifier_log(env, "size=%u", t->size); |
| } |
| |
| static const struct btf_kind_operations float_ops = { |
| .check_meta = btf_float_check_meta, |
| .resolve = btf_df_resolve, |
| .check_member = btf_float_check_member, |
| .check_kflag_member = btf_generic_check_kflag_member, |
| .log_details = btf_float_log, |
| .show = btf_df_show, |
| }; |
| |
| static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| const struct btf_decl_tag *tag; |
| u32 meta_needed = sizeof(*tag); |
| s32 component_idx; |
| const char *value; |
| |
| if (meta_left < meta_needed) { |
| btf_verifier_log_basic(env, t, |
| "meta_left:%u meta_needed:%u", |
| meta_left, meta_needed); |
| return -EINVAL; |
| } |
| |
| value = btf_name_by_offset(env->btf, t->name_off); |
| if (!value || !value[0]) { |
| btf_verifier_log_type(env, t, "Invalid value"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_vlen(t)) { |
| btf_verifier_log_type(env, t, "vlen != 0"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_kflag(t)) { |
| btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); |
| return -EINVAL; |
| } |
| |
| component_idx = btf_type_decl_tag(t)->component_idx; |
| if (component_idx < -1) { |
| btf_verifier_log_type(env, t, "Invalid component_idx"); |
| return -EINVAL; |
| } |
| |
| btf_verifier_log_type(env, t, NULL); |
| |
| return meta_needed; |
| } |
| |
| static int btf_decl_tag_resolve(struct btf_verifier_env *env, |
| const struct resolve_vertex *v) |
| { |
| const struct btf_type *next_type; |
| const struct btf_type *t = v->t; |
| u32 next_type_id = t->type; |
| struct btf *btf = env->btf; |
| s32 component_idx; |
| u32 vlen; |
| |
| next_type = btf_type_by_id(btf, next_type_id); |
| if (!next_type || !btf_type_is_decl_tag_target(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| if (!env_type_is_resolve_sink(env, next_type) && |
| !env_type_is_resolved(env, next_type_id)) |
| return env_stack_push(env, next_type, next_type_id); |
| |
| component_idx = btf_type_decl_tag(t)->component_idx; |
| if (component_idx != -1) { |
| if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) { |
| btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_is_struct(next_type)) { |
| vlen = btf_type_vlen(next_type); |
| } else { |
| /* next_type should be a function */ |
| next_type = btf_type_by_id(btf, next_type->type); |
| vlen = btf_type_vlen(next_type); |
| } |
| |
| if ((u32)component_idx >= vlen) { |
| btf_verifier_log_type(env, v->t, "Invalid component_idx"); |
| return -EINVAL; |
| } |
| } |
| |
| env_stack_pop_resolved(env, next_type_id, 0); |
| |
| return 0; |
| } |
| |
| static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t) |
| { |
| btf_verifier_log(env, "type=%u component_idx=%d", t->type, |
| btf_type_decl_tag(t)->component_idx); |
| } |
| |
| static const struct btf_kind_operations decl_tag_ops = { |
| .check_meta = btf_decl_tag_check_meta, |
| .resolve = btf_decl_tag_resolve, |
| .check_member = btf_df_check_member, |
| .check_kflag_member = btf_df_check_kflag_member, |
| .log_details = btf_decl_tag_log, |
| .show = btf_df_show, |
| }; |
| |
| static int btf_func_proto_check(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| const struct btf_type *ret_type; |
| const struct btf_param *args; |
| const struct btf *btf; |
| u16 nr_args, i; |
| int err; |
| |
| btf = env->btf; |
| args = (const struct btf_param *)(t + 1); |
| nr_args = btf_type_vlen(t); |
| |
| /* Check func return type which could be "void" (t->type == 0) */ |
| if (t->type) { |
| u32 ret_type_id = t->type; |
| |
| ret_type = btf_type_by_id(btf, ret_type_id); |
| if (!ret_type) { |
| btf_verifier_log_type(env, t, "Invalid return type"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_is_resolve_source_only(ret_type)) { |
| btf_verifier_log_type(env, t, "Invalid return type"); |
| return -EINVAL; |
| } |
| |
| if (btf_type_needs_resolve(ret_type) && |
| !env_type_is_resolved(env, ret_type_id)) { |
| err = btf_resolve(env, ret_type, ret_type_id); |
| if (err) |
| return err; |
| } |
| |
| /* Ensure the return type is a type that has a size */ |
| if (!btf_type_id_size(btf, &ret_type_id, NULL)) { |
| btf_verifier_log_type(env, t, "Invalid return type"); |
| return -EINVAL; |
| } |
| } |
| |
| if (!nr_args) |
| return 0; |
| |
| /* Last func arg type_id could be 0 if it is a vararg */ |
| if (!args[nr_args - 1].type) { |
| if (args[nr_args - 1].name_off) { |
| btf_verifier_log_type(env, t, "Invalid arg#%u", |
| nr_args); |
| return -EINVAL; |
| } |
| nr_args--; |
| } |
| |
| for (i = 0; i < nr_args; i++) { |
| const struct btf_type *arg_type; |
| u32 arg_type_id; |
| |
| arg_type_id = args[i].type; |
| arg_type = btf_type_by_id(btf, arg_type_id); |
| if (!arg_type) { |
| btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| return -EINVAL; |
| } |
| |
| if (btf_type_is_resolve_source_only(arg_type)) { |
| btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| return -EINVAL; |
| } |
| |
| if (args[i].name_off && |
| (!btf_name_offset_valid(btf, args[i].name_off) || |
| !btf_name_valid_identifier(btf, args[i].name_off))) { |
| btf_verifier_log_type(env, t, |
| "Invalid arg#%u", i + 1); |
| return -EINVAL; |
| } |
| |
| if (btf_type_needs_resolve(arg_type) && |
| !env_type_is_resolved(env, arg_type_id)) { |
| err = btf_resolve(env, arg_type, arg_type_id); |
| if (err) |
| return err; |
| } |
| |
| if (!btf_type_id_size(btf, &arg_type_id, NULL)) { |
| btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| return -EINVAL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int btf_func_check(struct btf_verifier_env *env, |
| const struct btf_type *t) |
| { |
| const struct btf_type *proto_type; |
| const struct btf_param *args; |
| const struct btf *btf; |
| u16 nr_args, i; |
| |
| btf = env->btf; |
| proto_type = btf_type_by_id(btf, t->type); |
| |
| if (!proto_type || !btf_type_is_func_proto(proto_type)) { |
| btf_verifier_log_type(env, t, "Invalid type_id"); |
| return -EINVAL; |
| } |
| |
| args = (const struct btf_param *)(proto_type + 1); |
| nr_args = btf_type_vlen(proto_type); |
| for (i = 0; i < nr_args; i++) { |
| if (!args[i].name_off && args[i].type) { |
| btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); |
| return -EINVAL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { |
| [BTF_KIND_INT] = &int_ops, |
| [BTF_KIND_PTR] = &ptr_ops, |
| [BTF_KIND_ARRAY] = &array_ops, |
| [BTF_KIND_STRUCT] = &struct_ops, |
| [BTF_KIND_UNION] = &struct_ops, |
| [BTF_KIND_ENUM] = &enum_ops, |
| [BTF_KIND_FWD] = &fwd_ops, |
| [BTF_KIND_TYPEDEF] = &modifier_ops, |
| [BTF_KIND_VOLATILE] = &modifier_ops, |
| [BTF_KIND_CONST] = &modifier_ops, |
| [BTF_KIND_RESTRICT] = &modifier_ops, |
| [BTF_KIND_FUNC] = &func_ops, |
| [BTF_KIND_FUNC_PROTO] = &func_proto_ops, |
| [BTF_KIND_VAR] = &var_ops, |
| [BTF_KIND_DATASEC] = &datasec_ops, |
| [BTF_KIND_FLOAT] = &float_ops, |
| [BTF_KIND_DECL_TAG] = &decl_tag_ops, |
| [BTF_KIND_TYPE_TAG] = &modifier_ops, |
| [BTF_KIND_ENUM64] = &enum64_ops, |
| }; |
| |
| static s32 btf_check_meta(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 meta_left) |
| { |
| u32 saved_meta_left = meta_left; |
| s32 var_meta_size; |
| |
| if (meta_left < sizeof(*t)) { |
| btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", |
| env->log_type_id, meta_left, sizeof(*t)); |
| return -EINVAL; |
| } |
| meta_left -= sizeof(*t); |
| |
| if (t->info & ~BTF_INFO_MASK) { |
| btf_verifier_log(env, "[%u] Invalid btf_info:%x", |
| env->log_type_id, t->info); |
| return -EINVAL; |
| } |
| |
| if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || |
| BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { |
| btf_verifier_log(env, "[%u] Invalid kind:%u", |
| env->log_type_id, BTF_INFO_KIND(t->info)); |
| return -EINVAL; |
| } |
| |
| if (!btf_name_offset_valid(env->btf, t->name_off)) { |
| btf_verifier_log(env, "[%u] Invalid name_offset:%u", |
| env->log_type_id, t->name_off); |
| return -EINVAL; |
| } |
| |
| var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); |
| if (var_meta_size < 0) |
| return var_meta_size; |
| |
| meta_left -= var_meta_size; |
| |
| return saved_meta_left - meta_left; |
| } |
| |
| static int btf_check_all_metas(struct btf_verifier_env *env) |
| { |
| struct btf *btf = env->btf; |
| struct btf_header *hdr; |
| void *cur, *end; |
| |
| hdr = &btf->hdr; |
| cur = btf->nohdr_data + hdr->type_off; |
| end = cur + hdr->type_len; |
| |
| env->log_type_id = btf->base_btf ? btf->start_id : 1; |
| while (cur < end) { |
| struct btf_type *t = cur; |
| s32 meta_size; |
| |
| meta_size = btf_check_meta(env, t, end - cur); |
| if (meta_size < 0) |
| return meta_size; |
| |
| btf_add_type(env, t); |
| cur += meta_size; |
| env->log_type_id++; |
| } |
| |
| return 0; |
| } |
| |
| static bool btf_resolve_valid(struct btf_verifier_env *env, |
| const struct btf_type *t, |
| u32 type_id) |
| { |
| struct btf *btf = env->btf; |
| |
| if (!env_type_is_resolved(env, type_id)) |
| return false; |
| |
| if (btf_type_is_struct(t) || btf_type_is_datasec(t)) |
| return !btf_resolved_type_id(btf, type_id) && |
| !btf_resolved_type_size(btf, type_id); |
| |
| if (btf_type_is_decl_tag(t) || btf_type_is_func(t)) |
| return btf_resolved_type_id(btf, type_id) && |
| !btf_resolved_type_size(btf, type_id); |
| |
| if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || |
| btf_type_is_var(t)) { |
| t = btf_type_id_resolve(btf, &type_id); |
| return t && |
| !btf_type_is_modifier(t) && |
| !btf_type_is_var(t) && |
| !btf_type_is_datasec(t); |
| } |
| |
| if (btf_type_is_array(t)) { |
| const struct btf_array *array = btf_type_array(t); |
| const struct btf_type *elem_type; |
| u32 elem_type_id = array->type; |
| u32 elem_size; |
| |
| elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); |
| return elem_type && !btf_type_is_modifier(elem_type) && |
| (array->nelems * elem_size == |
| btf_resolved_type_size(btf, type_id)); |
| } |
| |
| return false; |
| } |
| |
| static int btf_resolve(struct btf_verifier_env *env, |
| const struct btf_type *t, u32 type_id) |
| { |
| u32 save_log_type_id = env->log_type_id; |
| const struct resolve_vertex *v; |
| int err = 0; |
| |
| env->resolve_mode = RESOLVE_TBD; |
| env_stack_push(env, t, type_id); |
| while (!err && (v = env_stack_peak(env))) { |
| env->log_type_id = v->type_id; |
| err = btf_type_ops(v->t)->resolve(env, v); |
| } |
| |
| env->log_type_id = type_id; |
| if (err == -E2BIG) { |
| btf_verifier_log_type(env, t, |
| "Exceeded max resolving depth:%u", |
| MAX_RESOLVE_DEPTH); |
| } else if (err == -EEXIST) { |
| btf_verifier_log_type(env, t, "Loop detected"); |
| } |
| |
| /* Final sanity check */ |
| if (!err && !btf_resolve_valid(env, t, type_id)) { |
| btf_verifier_log_type(env, t, "Invalid resolve state"); |
| err = -EINVAL; |
| } |
| |
| env->log_type_id = save_log_type_id; |
| return err; |
| } |
| |
| static int btf_check_all_types(struct btf_verifier_env *env) |
| { |
| struct btf *btf = env->btf; |
| const struct btf_type *t; |
| u32 type_id, i; |
| int err; |
| |
| err = env_resolve_init(env); |
| if (err) |
| return err; |
| |
| env->phase++; |
| for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) { |
| type_id = btf->start_id + i; |
| t = btf_type_by_id(btf, type_id); |
| |
| env->log_type_id = type_id; |
| if (btf_type_needs_resolve(t) && |
| !env_type_is_resolved(env, type_id)) { |
| err = btf_resolve(env, t, type_id); |
| if (err) |
| return err; |
| } |
| |
| if (btf_type_is_func_proto(t)) { |
| err = btf_func_proto_check(env, t); |
| if (err) |
| return err; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int btf_parse_type_sec(struct btf_verifier_env *env) |
| { |
| const struct btf_header *hdr = &env->btf->hdr; |
| int err; |
| |
| /* Type section must align to 4 bytes */ |
| if (hdr->type_off & (sizeof(u32) - 1)) { |
| btf_verifier_log(env, "Unaligned type_off"); |
| return -EINVAL; |
| } |
| |
| if (!env->btf->base_btf && !hdr->type_len) { |
| btf_verifier_log(env, "No type found"); |
| return -EINVAL; |
| } |
| |
| err = btf_check_all_metas(env); |
| if (err) |
| return err; |
| |
| return btf_check_all_types(env); |
| } |
| |
| static int btf_parse_str_sec(struct btf_verifier_env *env) |
| { |
| const struct btf_header *hdr; |
| struct btf *btf = env->btf; |
| const char *start, *end; |
| |
| hdr = &btf->hdr; |
| start = btf->nohdr_data + hdr->str_off; |
| end = start + hdr->str_len; |
| |
| if (end != btf->data + btf->data_size) { |
| btf_verifier_log(env, "String section is not at the end"); |
| return -EINVAL; |
| } |
| |
| btf->strings = start; |
| |
| if (btf->base_btf && !hdr->str_len) |
| return 0; |
| if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) { |
| btf_verifier_log(env, "Invalid string section"); |
| return -EINVAL; |
| } |
| if (!btf->base_btf && start[0]) { |
| btf_verifier_log(env, "Invalid string section"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static const size_t btf_sec_info_offset[] = { |
| offsetof(struct btf_header, type_off), |
| offsetof(struct btf_header, str_off), |
| }; |
| |
| static int btf_sec_info_cmp(const void *a, const void *b) |
| { |
| const struct btf_sec_info *x = a; |
| const struct btf_sec_info *y = b; |
| |
| return (int)(x->off - y->off) ? : (int)(x->len - y->len); |
| } |
| |
| static int btf_check_sec_info(struct btf_verifier_env *env, |
| u32 btf_data_size) |
| { |
| struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; |
| u32 total, expected_total, i; |
| const struct btf_header *hdr; |
| const struct btf *btf; |
| |
| btf = env->btf; |
| hdr = &btf->hdr; |
| |
| /* Populate the secs from hdr */ |
| for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) |
| secs[i] = *(struct btf_sec_info *)((void *)hdr + |
| btf_sec_info_offset[i]); |
| |
| sort(secs, ARRAY_SIZE(btf_sec_info_offset), |
| sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); |
| |
| /* Check for gaps and overlap among sections */ |
| total = 0; |
| expected_total = btf_data_size - hdr->hdr_len; |
| for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { |
| if (expected_total < secs[i].off) { |
| btf_verifier_log(env, "Invalid section offset"); |
| return -EINVAL; |
| } |
| if (total < secs[i].off) { |
| /* gap */ |
| btf_verifier_log(env, "Unsupported section found"); |
| return -EINVAL; |
| } |
| if (total > secs[i].off) { |
| btf_verifier_log(env, "Section overlap found"); |
| return -EINVAL; |
| } |
| if (expected_total - total < secs[i].len) { |
| btf_verifier_log(env, |
| "Total section length too long"); |
| return -EINVAL; |
| } |
| total += secs[i].len; |
| } |
| |
| /* There is data other than hdr and known sections */ |
| if (expected_total != total) { |
| btf_verifier_log(env, "Unsupported section found"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_parse_hdr(struct btf_verifier_env *env) |
| { |
| u32 hdr_len, hdr_copy, btf_data_size; |
| const struct btf_header *hdr; |
| struct btf *btf; |
| |
| btf = env->btf; |
| btf_data_size = btf->data_size; |
| |
| if (btf_data_size < offsetofend(struct btf_header, hdr_len)) { |
| btf_verifier_log(env, "hdr_len not found"); |
| return -EINVAL; |
| } |
| |
| hdr = btf->data; |
| hdr_len = hdr->hdr_len; |
| if (btf_data_size < hdr_len) { |
| btf_verifier_log(env, "btf_header not found"); |
| return -EINVAL; |
| } |
| |
| /* Ensure the unsupported header fields are zero */ |
| if (hdr_len > sizeof(btf->hdr)) { |
| u8 *expected_zero = btf->data + sizeof(btf->hdr); |
| u8 *end = btf->data + hdr_len; |
| |
| for (; expected_zero < end; expected_zero++) { |
| if (*expected_zero) { |
| btf_verifier_log(env, "Unsupported btf_header"); |
| return -E2BIG; |
| } |
| } |
| } |
| |
| hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); |
| memcpy(&btf->hdr, btf->data, hdr_copy); |
| |
| hdr = &btf->hdr; |
| |
| btf_verifier_log_hdr(env, btf_data_size); |
| |
| if (hdr->magic != BTF_MAGIC) { |
| btf_verifier_log(env, "Invalid magic"); |
| return -EINVAL; |
| } |
| |
| if (hdr->version != BTF_VERSION) { |
| btf_verifier_log(env, "Unsupported version"); |
| return -ENOTSUPP; |
| } |
| |
| if (hdr->flags) { |
| btf_verifier_log(env, "Unsupported flags"); |
| return -ENOTSUPP; |
| } |
| |
| if (!btf->base_btf && btf_data_size == hdr->hdr_len) { |
| btf_verifier_log(env, "No data"); |
| return -EINVAL; |
| } |
| |
| return btf_check_sec_info(env, btf_data_size); |
| } |
| |
| static const char *alloc_obj_fields[] = { |
| "bpf_spin_lock", |
| "bpf_list_head", |
| "bpf_list_node", |
| "bpf_rb_root", |
| "bpf_rb_node", |
| "bpf_refcount", |
| }; |
| |
| static struct btf_struct_metas * |
| btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf) |
| { |
| struct btf_struct_metas *tab = NULL; |
| struct btf_id_set *aof; |
| int i, n, id, ret; |
| |
| BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0); |
| BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32)); |
| |
| aof = kmalloc(sizeof(*aof), GFP_KERNEL | __GFP_NOWARN); |
| if (!aof) |
| return ERR_PTR(-ENOMEM); |
| aof->cnt = 0; |
| |
| for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) { |
| /* Try to find whether this special type exists in user BTF, and |
| * if so remember its ID so we can easily find it among members |
| * of structs that we iterate in the next loop. |
| */ |
| struct btf_id_set *new_aof; |
| |
| id = btf_find_by_name_kind(btf, alloc_obj_fields[i], BTF_KIND_STRUCT); |
| if (id < 0) |
| continue; |
| |
| new_aof = krealloc(aof, offsetof(struct btf_id_set, ids[aof->cnt + 1]), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!new_aof) { |
| ret = -ENOMEM; |
| goto free_aof; |
| } |
| aof = new_aof; |
| aof->ids[aof->cnt++] = id; |
| } |
| |
| n = btf_nr_types(btf); |
| for (i = 1; i < n; i++) { |
| /* Try to find if there are kptrs in user BTF and remember their ID */ |
| struct btf_id_set *new_aof; |
| struct btf_field_info tmp; |
| const struct btf_type *t; |
| |
| t = btf_type_by_id(btf, i); |
| if (!t) { |
| ret = -EINVAL; |
| goto free_aof; |
| } |
| |
| ret = btf_find_kptr(btf, t, 0, 0, &tmp); |
| if (ret != BTF_FIELD_FOUND) |
| continue; |
| |
| new_aof = krealloc(aof, offsetof(struct btf_id_set, ids[aof->cnt + 1]), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!new_aof) { |
| ret = -ENOMEM; |
| goto free_aof; |
| } |
| aof = new_aof; |
| aof->ids[aof->cnt++] = i; |
| } |
| |
| if (!aof->cnt) { |
| kfree(aof); |
| return NULL; |
| } |
| sort(&aof->ids, aof->cnt, sizeof(aof->ids[0]), btf_id_cmp_func, NULL); |
| |
| for (i = 1; i < n; i++) { |
| struct btf_struct_metas *new_tab; |
| const struct btf_member *member; |
| struct btf_struct_meta *type; |
| struct btf_record *record; |
| const struct btf_type *t; |
| int j, tab_cnt; |
| |
| t = btf_type_by_id(btf, i); |
| if (!__btf_type_is_struct(t)) |
| continue; |
| |
| cond_resched(); |
| |
| for_each_member(j, t, member) { |
| if (btf_id_set_contains(aof, member->type)) |
| goto parse; |
| } |
| continue; |
| parse: |
| tab_cnt = tab ? tab->cnt : 0; |
| new_tab = krealloc(tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!new_tab) { |
| ret = -ENOMEM; |
| goto free; |
| } |
| if (!tab) |
| new_tab->cnt = 0; |
| tab = new_tab; |
| |
| type = &tab->types[tab->cnt]; |
| type->btf_id = i; |
| record = btf_parse_fields(btf, t, BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE | |
| BPF_RB_ROOT | BPF_RB_NODE | BPF_REFCOUNT | |
| BPF_KPTR, t->size); |
| /* The record cannot be unset, treat it as an error if so */ |
| if (IS_ERR_OR_NULL(record)) { |
| ret = PTR_ERR_OR_ZERO(record) ?: -EFAULT; |
| goto free; |
| } |
| type->record = record; |
| tab->cnt++; |
| } |
| kfree(aof); |
| return tab; |
| free: |
| btf_struct_metas_free(tab); |
| free_aof: |
| kfree(aof); |
| return ERR_PTR(ret); |
| } |
| |
| struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id) |
| { |
| struct btf_struct_metas *tab; |
| |
| BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0); |
| tab = btf->struct_meta_tab; |
| if (!tab) |
| return NULL; |
| return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func); |
| } |
| |
| static int btf_check_type_tags(struct btf_verifier_env *env, |
| struct btf *btf, int start_id) |
| { |
| int i, n, good_id = start_id - 1; |
| bool in_tags; |
| |
| n = btf_nr_types(btf); |
| for (i = start_id; i < n; i++) { |
| const struct btf_type *t; |
| int chain_limit = 32; |
| u32 cur_id = i; |
| |
| t = btf_type_by_id(btf, i); |
| if (!t) |
| return -EINVAL; |
| if (!btf_type_is_modifier(t)) |
| continue; |
| |
| cond_resched(); |
| |
| in_tags = btf_type_is_type_tag(t); |
| while (btf_type_is_modifier(t)) { |
| if (!chain_limit--) { |
| btf_verifier_log(env, "Max chain length or cycle detected"); |
| return -ELOOP; |
| } |
| if (btf_type_is_type_tag(t)) { |
| if (!in_tags) { |
| btf_verifier_log(env, "Type tags don't precede modifiers"); |
| return -EINVAL; |
| } |
| } else if (in_tags) { |
| in_tags = false; |
| } |
| if (cur_id <= good_id) |
| break; |
| /* Move to next type */ |
| cur_id = t->type; |
| t = btf_type_by_id(btf, cur_id); |
| if (!t) |
| return -EINVAL; |
| } |
| good_id = i; |
| } |
| return 0; |
| } |
| |
| static int finalize_log(struct bpf_verifier_log *log, bpfptr_t uattr, u32 uattr_size) |
| { |
| u32 log_true_size; |
| int err; |
| |
| err = bpf_vlog_finalize(log, &log_true_size); |
| |
| if (uattr_size >= offsetofend(union bpf_attr, btf_log_true_size) && |
| copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, btf_log_true_size), |
| &log_true_size, sizeof(log_true_size))) |
| err = -EFAULT; |
| |
| return err; |
| } |
| |
| static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) |
| { |
| bpfptr_t btf_data = make_bpfptr(attr->btf, uattr.is_kernel); |
| char __user *log_ubuf = u64_to_user_ptr(attr->btf_log_buf); |
| struct btf_struct_metas *struct_meta_tab; |
| struct btf_verifier_env *env = NULL; |
| struct btf *btf = NULL; |
| u8 *data; |
| int err, ret; |
| |
| if (attr->btf_size > BTF_MAX_SIZE) |
| return ERR_PTR(-E2BIG); |
| |
| env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
| if (!env) |
| return ERR_PTR(-ENOMEM); |
| |
| /* user could have requested verbose verifier output |
| * and supplied buffer to store the verification trace |
| */ |
| err = bpf_vlog_init(&env->log, attr->btf_log_level, |
| log_ubuf, attr->btf_log_size); |
| if (err) |
| goto errout_free; |
| |
| btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
| if (!btf) { |
| err = -ENOMEM; |
| goto errout; |
| } |
| env->btf = btf; |
| |
| data = kvmalloc(attr->btf_size, GFP_KERNEL | __GFP_NOWARN); |
| if (!data) { |
| err = -ENOMEM; |
| goto errout; |
| } |
| |
| btf->data = data; |
| btf->data_size = attr->btf_size; |
| |
| if (copy_from_bpfptr(data, btf_data, attr->btf_size)) { |
| err = -EFAULT; |
| goto errout; |
| } |
| |
| err = btf_parse_hdr(env); |
| if (err) |
| goto errout; |
| |
| btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
| |
| err = btf_parse_str_sec(env); |
| if (err) |
| goto errout; |
| |
| err = btf_parse_type_sec(env); |
| if (err) |
| goto errout; |
| |
| err = btf_check_type_tags(env, btf, 1); |
| if (err) |
| goto errout; |
| |
| struct_meta_tab = btf_parse_struct_metas(&env->log, btf); |
| if (IS_ERR(struct_meta_tab)) { |
| err = PTR_ERR(struct_meta_tab); |
| goto errout; |
| } |
| btf->struct_meta_tab = struct_meta_tab; |
| |
| if (struct_meta_tab) { |
| int i; |
| |
| for (i = 0; i < struct_meta_tab->cnt; i++) { |
| err = btf_check_and_fixup_fields(btf, struct_meta_tab->types[i].record); |
| if (err < 0) |
| goto errout_meta; |
| } |
| } |
| |
| err = finalize_log(&env->log, uattr, uattr_size); |
| if (err) |
| goto errout_free; |
| |
| btf_verifier_env_free(env); |
| refcount_set(&btf->refcnt, 1); |
| return btf; |
| |
| errout_meta: |
| btf_free_struct_meta_tab(btf); |
| errout: |
| /* overwrite err with -ENOSPC or -EFAULT */ |
| ret = finalize_log(&env->log, uattr, uattr_size); |
| if (ret) |
| err = ret; |
| errout_free: |
| btf_verifier_env_free(env); |
| if (btf) |
| btf_free(btf); |
| return ERR_PTR(err); |
| } |
| |
| extern char __start_BTF[]; |
| extern char __stop_BTF[]; |
| extern struct btf *btf_vmlinux; |
| |
| #define BPF_MAP_TYPE(_id, _ops) |
| #define BPF_LINK_TYPE(_id, _name) |
| static union { |
| struct bpf_ctx_convert { |
| #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
| prog_ctx_type _id##_prog; \ |
| kern_ctx_type _id##_kern; |
| #include <linux/bpf_types.h> |
| #undef BPF_PROG_TYPE |
| } *__t; |
| /* 't' is written once under lock. Read many times. */ |
| const struct btf_type *t; |
| } bpf_ctx_convert; |
| enum { |
| #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
| __ctx_convert##_id, |
| #include <linux/bpf_types.h> |
| #undef BPF_PROG_TYPE |
| __ctx_convert_unused, /* to avoid empty enum in extreme .config */ |
| }; |
| static u8 bpf_ctx_convert_map[] = { |
| #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ |
| [_id] = __ctx_convert##_id, |
| #include <linux/bpf_types.h> |
| #undef BPF_PROG_TYPE |
| 0, /* avoid empty array */ |
| }; |
| #undef BPF_MAP_TYPE |
| #undef BPF_LINK_TYPE |
| |
| static const struct btf_type *find_canonical_prog_ctx_type(enum bpf_prog_type prog_type) |
| { |
| const struct btf_type *conv_struct; |
| const struct btf_member *ctx_type; |
| |
| conv_struct = bpf_ctx_convert.t; |
| if (!conv_struct) |
| return NULL; |
| /* prog_type is valid bpf program type. No need for bounds check. */ |
| ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2; |
| /* ctx_type is a pointer to prog_ctx_type in vmlinux. |
| * Like 'struct __sk_buff' |
| */ |
| return btf_type_by_id(btf_vmlinux, ctx_type->type); |
| } |
| |
| static int find_kern_ctx_type_id(enum bpf_prog_type prog_type) |
| { |
| const struct btf_type *conv_struct; |
| const struct btf_member *ctx_type; |
| |
| conv_struct = bpf_ctx_convert.t; |
| if (!conv_struct) |
| return -EFAULT; |
| /* prog_type is valid bpf program type. No need for bounds check. */ |
| ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; |
| /* ctx_type is a pointer to prog_ctx_type in vmlinux. |
| * Like 'struct sk_buff' |
| */ |
| return ctx_type->type; |
| } |
| |
| bool btf_is_projection_of(const char *pname, const char *tname) |
| { |
| if (strcmp(pname, "__sk_buff") == 0 && strcmp(tname, "sk_buff") == 0) |
| return true; |
| if (strcmp(pname, "xdp_md") == 0 && strcmp(tname, "xdp_buff") == 0) |
| return true; |
| return false; |
| } |
| |
| bool btf_is_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
| const struct btf_type *t, enum bpf_prog_type prog_type, |
| int arg) |
| { |
| const struct btf_type *ctx_type; |
| const char *tname, *ctx_tname; |
| |
| t = btf_type_by_id(btf, t->type); |
| |
| /* KPROBE programs allow bpf_user_pt_regs_t typedef, which we need to |
| * check before we skip all the typedef below. |
| */ |
| if (prog_type == BPF_PROG_TYPE_KPROBE) { |
| while (btf_type_is_modifier(t) && !btf_type_is_typedef(t)) |
| t = btf_type_by_id(btf, t->type); |
| |
| if (btf_type_is_typedef(t)) { |
| tname = btf_name_by_offset(btf, t->name_off); |
| if (tname && strcmp(tname, "bpf_user_pt_regs_t") == 0) |
| return true; |
| } |
| } |
| |
| while (btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| if (!btf_type_is_struct(t)) { |
| /* Only pointer to struct is supported for now. |
| * That means that BPF_PROG_TYPE_TRACEPOINT with BTF |
| * is not supported yet. |
| * BPF_PROG_TYPE_RAW_TRACEPOINT is fine. |
| */ |
| return false; |
| } |
| tname = btf_name_by_offset(btf, t->name_off); |
| if (!tname) { |
| bpf_log(log, "arg#%d struct doesn't have a name\n", arg); |
| return false; |
| } |
| |
| ctx_type = find_canonical_prog_ctx_type(prog_type); |
| if (!ctx_type) { |
| bpf_log(log, "btf_vmlinux is malformed\n"); |
| /* should not happen */ |
| return false; |
| } |
| again: |
| ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off); |
| if (!ctx_tname) { |
| /* should not happen */ |
| bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n"); |
| return false; |
| } |
| /* program types without named context types work only with arg:ctx tag */ |
| if (ctx_tname[0] == '\0') |
| return false; |
| /* only compare that prog's ctx type name is the same as |
| * kernel expects. No need to compare field by field. |
| * It's ok for bpf prog to do: |
| * struct __sk_buff {}; |
| * int socket_filter_bpf_prog(struct __sk_buff *skb) |
| * { // no fields of skb are ever used } |
| */ |
| if (btf_is_projection_of(ctx_tname, tname)) |
| return true; |
| if (strcmp(ctx_tname, tname)) { |
| /* bpf_user_pt_regs_t is a typedef, so resolve it to |
| * underlying struct and check name again |
| */ |
| if (!btf_type_is_modifier(ctx_type)) |
| return false; |
| while (btf_type_is_modifier(ctx_type)) |
| ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type); |
| goto again; |
| } |
| return true; |
| } |
| |
| /* forward declarations for arch-specific underlying types of |
| * bpf_user_pt_regs_t; this avoids the need for arch-specific #ifdef |
| * compilation guards below for BPF_PROG_TYPE_PERF_EVENT checks, but still |
| * works correctly with __builtin_types_compatible_p() on respective |
| * architectures |
| */ |
| struct user_regs_struct; |
| struct user_pt_regs; |
| |
| static int btf_validate_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf, |
| const struct btf_type *t, int arg, |
| enum bpf_prog_type prog_type, |
| enum bpf_attach_type attach_type) |
| { |
| const struct btf_type *ctx_type; |
| const char *tname, *ctx_tname; |
| |
| if (!btf_is_ptr(t)) { |
| bpf_log(log, "arg#%d type isn't a pointer\n", arg); |
| return -EINVAL; |
| } |
| t = btf_type_by_id(btf, t->type); |
| |
| /* KPROBE and PERF_EVENT programs allow bpf_user_pt_regs_t typedef */ |
| if (prog_type == BPF_PROG_TYPE_KPROBE || prog_type == BPF_PROG_TYPE_PERF_EVENT) { |
| while (btf_type_is_modifier(t) && !btf_type_is_typedef(t)) |
| t = btf_type_by_id(btf, t->type); |
| |
| if (btf_type_is_typedef(t)) { |
| tname = btf_name_by_offset(btf, t->name_off); |
| if (tname && strcmp(tname, "bpf_user_pt_regs_t") == 0) |
| return 0; |
| } |
| } |
| |
| /* all other program types don't use typedefs for context type */ |
| while (btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| |
| /* `void *ctx __arg_ctx` is always valid */ |
| if (btf_type_is_void(t)) |
| return 0; |
| |
| tname = btf_name_by_offset(btf, t->name_off); |
| if (str_is_empty(tname)) { |
| bpf_log(log, "arg#%d type doesn't have a name\n", arg); |
| return -EINVAL; |
| } |
| |
| /* special cases */ |
| switch (prog_type) { |
| case BPF_PROG_TYPE_KPROBE: |
| if (__btf_type_is_struct(t) && strcmp(tname, "pt_regs") == 0) |
| return 0; |
| break; |
| case BPF_PROG_TYPE_PERF_EVENT: |
| if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct pt_regs) && |
| __btf_type_is_struct(t) && strcmp(tname, "pt_regs") == 0) |
| return 0; |
| if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_pt_regs) && |
| __btf_type_is_struct(t) && strcmp(tname, "user_pt_regs") == 0) |
| return 0; |
| if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_regs_struct) && |
| __btf_type_is_struct(t) && strcmp(tname, "user_regs_struct") == 0) |
| return 0; |
| break; |
| case BPF_PROG_TYPE_RAW_TRACEPOINT: |
| case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: |
| /* allow u64* as ctx */ |
| if (btf_is_int(t) && t->size == 8) |
| return 0; |
| break; |
| case BPF_PROG_TYPE_TRACING: |
| switch (attach_type) { |
| case BPF_TRACE_RAW_TP: |
| /* tp_btf program is TRACING, so need special case here */ |
| if (__btf_type_is_struct(t) && |
| strcmp(tname, "bpf_raw_tracepoint_args") == 0) |
| return 0; |
| /* allow u64* as ctx */ |
| if (btf_is_int(t) && t->size == 8) |
| return 0; |
| break; |
| case BPF_TRACE_ITER: |
| /* allow struct bpf_iter__xxx types only */ |
| if (__btf_type_is_struct(t) && |
| strncmp(tname, "bpf_iter__", sizeof("bpf_iter__") - 1) == 0) |
| return 0; |
| break; |
| case BPF_TRACE_FENTRY: |
| case BPF_TRACE_FEXIT: |
| case BPF_MODIFY_RETURN: |
| /* allow u64* as ctx */ |
| if (btf_is_int(t) && t->size == 8) |
| return 0; |
| break; |
| default: |
| break; |
| } |
| break; |
| case BPF_PROG_TYPE_LSM: |
| case BPF_PROG_TYPE_STRUCT_OPS: |
| /* allow u64* as ctx */ |
| if (btf_is_int(t) && t->size == 8) |
| return 0; |
| break; |
| case BPF_PROG_TYPE_TRACEPOINT: |
| case BPF_PROG_TYPE_SYSCALL: |
| case BPF_PROG_TYPE_EXT: |
| return 0; /* anything goes */ |
| default: |
| break; |
| } |
| |
| ctx_type = find_canonical_prog_ctx_type(prog_type); |
| if (!ctx_type) { |
| /* should not happen */ |
| bpf_log(log, "btf_vmlinux is malformed\n"); |
| return -EINVAL; |
| } |
| |
| /* resolve typedefs and check that underlying structs are matching as well */ |
| while (btf_type_is_modifier(ctx_type)) |
| ctx_type = btf_type_by_id(btf_vmlinux, ctx_type->type); |
| |
| /* if program type doesn't have distinctly named struct type for |
| * context, then __arg_ctx argument can only be `void *`, which we |
| * already checked above |
| */ |
| if (!__btf_type_is_struct(ctx_type)) { |
| bpf_log(log, "arg#%d should be void pointer\n", arg); |
| return -EINVAL; |
| } |
| |
| ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_type->name_off); |
| if (!__btf_type_is_struct(t) || strcmp(ctx_tname, tname) != 0) { |
| bpf_log(log, "arg#%d should be `struct %s *`\n", arg, ctx_tname); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_translate_to_vmlinux(struct bpf_verifier_log *log, |
| struct btf *btf, |
| const struct btf_type *t, |
| enum bpf_prog_type prog_type, |
| int arg) |
| { |
| if (!btf_is_prog_ctx_type(log, btf, t, prog_type, arg)) |
| return -ENOENT; |
| return find_kern_ctx_type_id(prog_type); |
| } |
| |
| int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type) |
| { |
| const struct btf_member *kctx_member; |
| const struct btf_type *conv_struct; |
| const struct btf_type *kctx_type; |
| u32 kctx_type_id; |
| |
| conv_struct = bpf_ctx_convert.t; |
| /* get member for kernel ctx type */ |
| kctx_member = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1; |
| kctx_type_id = kctx_member->type; |
| kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id); |
| if (!btf_type_is_struct(kctx_type)) { |
| bpf_log(log, "kern ctx type id %u is not a struct\n", kctx_type_id); |
| return -EINVAL; |
| } |
| |
| return kctx_type_id; |
| } |
| |
| BTF_ID_LIST(bpf_ctx_convert_btf_id) |
| BTF_ID(struct, bpf_ctx_convert) |
| |
| static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name, |
| void *data, unsigned int data_size) |
| { |
| struct btf *btf = NULL; |
| int err; |
| |
| if (!IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) |
| return ERR_PTR(-ENOENT); |
| |
| btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
| if (!btf) { |
| err = -ENOMEM; |
| goto errout; |
| } |
| env->btf = btf; |
| |
| btf->data = data; |
| btf->data_size = data_size; |
| btf->kernel_btf = true; |
| snprintf(btf->name, sizeof(btf->name), "%s", name); |
| |
| err = btf_parse_hdr(env); |
| if (err) |
| goto errout; |
| |
| btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
| |
| err = btf_parse_str_sec(env); |
| if (err) |
| goto errout; |
| |
| err = btf_check_all_metas(env); |
| if (err) |
| goto errout; |
| |
| err = btf_check_type_tags(env, btf, 1); |
| if (err) |
| goto errout; |
| |
| refcount_set(&btf->refcnt, 1); |
| |
| return btf; |
| |
| errout: |
| if (btf) { |
| kvfree(btf->types); |
| kfree(btf); |
| } |
| return ERR_PTR(err); |
| } |
| |
| struct btf *btf_parse_vmlinux(void) |
| { |
| struct btf_verifier_env *env = NULL; |
| struct bpf_verifier_log *log; |
| struct btf *btf; |
| int err; |
| |
| env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
| if (!env) |
| return ERR_PTR(-ENOMEM); |
| |
| log = &env->log; |
| log->level = BPF_LOG_KERNEL; |
| btf = btf_parse_base(env, "vmlinux", __start_BTF, __stop_BTF - __start_BTF); |
| if (IS_ERR(btf)) |
| goto err_out; |
| |
| /* btf_parse_vmlinux() runs under bpf_verifier_lock */ |
| bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]); |
| err = btf_alloc_id(btf); |
| if (err) { |
| btf_free(btf); |
| btf = ERR_PTR(err); |
| } |
| err_out: |
| btf_verifier_env_free(env); |
| return btf; |
| } |
| |
| /* If .BTF_ids section was created with distilled base BTF, both base and |
| * split BTF ids will need to be mapped to actual base/split ids for |
| * BTF now that it has been relocated. |
| */ |
| static __u32 btf_relocate_id(const struct btf *btf, __u32 id) |
| { |
| if (!btf->base_btf || !btf->base_id_map) |
| return id; |
| return btf->base_id_map[id]; |
| } |
| |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| |
| static struct btf *btf_parse_module(const char *module_name, const void *data, |
| unsigned int data_size, void *base_data, |
| unsigned int base_data_size) |
| { |
| struct btf *btf = NULL, *vmlinux_btf, *base_btf = NULL; |
| struct btf_verifier_env *env = NULL; |
| struct bpf_verifier_log *log; |
| int err = 0; |
| |
| vmlinux_btf = bpf_get_btf_vmlinux(); |
| if (IS_ERR(vmlinux_btf)) |
| return vmlinux_btf; |
| if (!vmlinux_btf) |
| return ERR_PTR(-EINVAL); |
| |
| env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); |
| if (!env) |
| return ERR_PTR(-ENOMEM); |
| |
| log = &env->log; |
| log->level = BPF_LOG_KERNEL; |
| |
| if (base_data) { |
| base_btf = btf_parse_base(env, ".BTF.base", base_data, base_data_size); |
| if (IS_ERR(base_btf)) { |
| err = PTR_ERR(base_btf); |
| goto errout; |
| } |
| } else { |
| base_btf = vmlinux_btf; |
| } |
| |
| btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); |
| if (!btf) { |
| err = -ENOMEM; |
| goto errout; |
| } |
| env->btf = btf; |
| |
| btf->base_btf = base_btf; |
| btf->start_id = base_btf->nr_types; |
| btf->start_str_off = base_btf->hdr.str_len; |
| btf->kernel_btf = true; |
| snprintf(btf->name, sizeof(btf->name), "%s", module_name); |
| |
| btf->data = kvmemdup(data, data_size, GFP_KERNEL | __GFP_NOWARN); |
| if (!btf->data) { |
| err = -ENOMEM; |
| goto errout; |
| } |
| btf->data_size = data_size; |
| |
| err = btf_parse_hdr(env); |
| if (err) |
| goto errout; |
| |
| btf->nohdr_data = btf->data + btf->hdr.hdr_len; |
| |
| err = btf_parse_str_sec(env); |
| if (err) |
| goto errout; |
| |
| err = btf_check_all_metas(env); |
| if (err) |
| goto errout; |
| |
| err = btf_check_type_tags(env, btf, btf_nr_types(base_btf)); |
| if (err) |
| goto errout; |
| |
| if (base_btf != vmlinux_btf) { |
| err = btf_relocate(btf, vmlinux_btf, &btf->base_id_map); |
| if (err) |
| goto errout; |
| btf_free(base_btf); |
| base_btf = vmlinux_btf; |
| } |
| |
| btf_verifier_env_free(env); |
| refcount_set(&btf->refcnt, 1); |
| return btf; |
| |
| errout: |
| btf_verifier_env_free(env); |
| if (!IS_ERR(base_btf) && base_btf != vmlinux_btf) |
| btf_free(base_btf); |
| if (btf) { |
| kvfree(btf->data); |
| kvfree(btf->types); |
| kfree(btf); |
| } |
| return ERR_PTR(err); |
| } |
| |
| #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
| |
| struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog) |
| { |
| struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
| |
| if (tgt_prog) |
| return tgt_prog->aux->btf; |
| else |
| return prog->aux->attach_btf; |
| } |
| |
| static bool is_int_ptr(struct btf *btf, const struct btf_type *t) |
| { |
| /* skip modifiers */ |
| t = btf_type_skip_modifiers(btf, t->type, NULL); |
| |
| return btf_type_is_int(t); |
| } |
| |
| static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, |
| int off) |
| { |
| const struct btf_param *args; |
| const struct btf_type *t; |
| u32 offset = 0, nr_args; |
| int i; |
| |
| if (!func_proto) |
| return off / 8; |
| |
| nr_args = btf_type_vlen(func_proto); |
| args = (const struct btf_param *)(func_proto + 1); |
| for (i = 0; i < nr_args; i++) { |
| t = btf_type_skip_modifiers(btf, args[i].type, NULL); |
| offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); |
| if (off < offset) |
| return i; |
| } |
| |
| t = btf_type_skip_modifiers(btf, func_proto->type, NULL); |
| offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8); |
| if (off < offset) |
| return nr_args; |
| |
| return nr_args + 1; |
| } |
| |
| static bool prog_args_trusted(const struct bpf_prog *prog) |
| { |
| enum bpf_attach_type atype = prog->expected_attach_type; |
| |
| switch (prog->type) { |
| case BPF_PROG_TYPE_TRACING: |
| return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER; |
| case BPF_PROG_TYPE_LSM: |
| return bpf_lsm_is_trusted(prog); |
| case BPF_PROG_TYPE_STRUCT_OPS: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto, |
| u32 arg_no) |
| { |
| const struct btf_param *args; |
| const struct btf_type *t; |
| int off = 0, i; |
| u32 sz; |
| |
| args = btf_params(func_proto); |
| for (i = 0; i < arg_no; i++) { |
| t = btf_type_by_id(btf, args[i].type); |
| t = btf_resolve_size(btf, t, &sz); |
| if (IS_ERR(t)) |
| return PTR_ERR(t); |
| off += roundup(sz, 8); |
| } |
| |
| return off; |
| } |
| |
| bool btf_ctx_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| const struct btf_type *t = prog->aux->attach_func_proto; |
| struct bpf_prog *tgt_prog = prog->aux->dst_prog; |
| struct btf *btf = bpf_prog_get_target_btf(prog); |
| const char *tname = prog->aux->attach_func_name; |
| struct bpf_verifier_log *log = info->log; |
| const struct btf_param *args; |
| const char *tag_value; |
| u32 nr_args, arg; |
| int i, ret; |
| |
| if (off % 8) { |
| bpf_log(log, "func '%s' offset %d is not multiple of 8\n", |
| tname, off); |
| return false; |
| } |
| arg = get_ctx_arg_idx(btf, t, off); |
| args = (const struct btf_param *)(t + 1); |
| /* if (t == NULL) Fall back to default BPF prog with |
| * MAX_BPF_FUNC_REG_ARGS u64 arguments. |
| */ |
| nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS; |
| if (prog->aux->attach_btf_trace) { |
| /* skip first 'void *__data' argument in btf_trace_##name typedef */ |
| args++; |
| nr_args--; |
| } |
| |
| if (arg > nr_args) { |
| bpf_log(log, "func '%s' doesn't have %d-th argument\n", |
| tname, arg + 1); |
| return false; |
| } |
| |
| if (arg == nr_args) { |
| switch (prog->expected_attach_type) { |
| case BPF_LSM_MAC: |
| /* mark we are accessing the return value */ |
| info->is_retval = true; |
| fallthrough; |
| case BPF_LSM_CGROUP: |
| case BPF_TRACE_FEXIT: |
| /* When LSM programs are attached to void LSM hooks |
| * they use FEXIT trampolines and when attached to |
| * int LSM hooks, they use MODIFY_RETURN trampolines. |
| * |
| * While the LSM programs are BPF_MODIFY_RETURN-like |
| * the check: |
| * |
| * if (ret_type != 'int') |
| * return -EINVAL; |
| * |
| * is _not_ done here. This is still safe as LSM hooks |
| * have only void and int return types. |
| */ |
| if (!t) |
| return true; |
| t = btf_type_by_id(btf, t->type); |
| break; |
| case BPF_MODIFY_RETURN: |
| /* For now the BPF_MODIFY_RETURN can only be attached to |
| * functions that return an int. |
| */ |
| if (!t) |
| return false; |
| |
| t = btf_type_skip_modifiers(btf, t->type, NULL); |
| if (!btf_type_is_small_int(t)) { |
| bpf_log(log, |
| "ret type %s not allowed for fmod_ret\n", |
| btf_type_str(t)); |
| return false; |
| } |
| break; |
| default: |
| bpf_log(log, "func '%s' doesn't have %d-th argument\n", |
| tname, arg + 1); |
| return false; |
| } |
| } else { |
| if (!t) |
| /* Default prog with MAX_BPF_FUNC_REG_ARGS args */ |
| return true; |
| t = btf_type_by_id(btf, args[arg].type); |
| } |
| |
| /* skip modifiers */ |
| while (btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
| /* accessing a scalar */ |
| return true; |
| if (!btf_type_is_ptr(t)) { |
| bpf_log(log, |
| "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", |
| tname, arg, |
| __btf_name_by_offset(btf, t->name_off), |
| btf_type_str(t)); |
| return false; |
| } |
| |
| /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ |
| for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
| const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; |
| u32 type, flag; |
| |
| type = base_type(ctx_arg_info->reg_type); |
| flag = type_flag(ctx_arg_info->reg_type); |
| if (ctx_arg_info->offset == off && type == PTR_TO_BUF && |
| (flag & PTR_MAYBE_NULL)) { |
| info->reg_type = ctx_arg_info->reg_type; |
| return true; |
| } |
| } |
| |
| if (t->type == 0) |
| /* This is a pointer to void. |
| * It is the same as scalar from the verifier safety pov. |
| * No further pointer walking is allowed. |
| */ |
| return true; |
| |
| if (is_int_ptr(btf, t)) |
| return true; |
| |
| /* this is a pointer to another type */ |
| for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { |
| const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; |
| |
| if (ctx_arg_info->offset == off) { |
| if (!ctx_arg_info->btf_id) { |
| bpf_log(log,"invalid btf_id for context argument offset %u\n", off); |
| return false; |
| } |
| |
| info->reg_type = ctx_arg_info->reg_type; |
| info->btf = ctx_arg_info->btf ? : btf_vmlinux; |
| info->btf_id = ctx_arg_info->btf_id; |
| return true; |
| } |
| } |
| |
| info->reg_type = PTR_TO_BTF_ID; |
| if (prog_args_trusted(prog)) |
| info->reg_type |= PTR_TRUSTED; |
| |
| if (btf_param_match_suffix(btf, &args[arg], "__nullable")) |
| info->reg_type |= PTR_MAYBE_NULL; |
| |
| if (tgt_prog) { |
| enum bpf_prog_type tgt_type; |
| |
| if (tgt_prog->type == BPF_PROG_TYPE_EXT) |
| tgt_type = tgt_prog->aux->saved_dst_prog_type; |
| else |
| tgt_type = tgt_prog->type; |
| |
| ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); |
| if (ret > 0) { |
| info->btf = btf_vmlinux; |
| info->btf_id = ret; |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| info->btf = btf; |
| info->btf_id = t->type; |
| t = btf_type_by_id(btf, t->type); |
| |
| if (btf_type_is_type_tag(t)) { |
| tag_value = __btf_name_by_offset(btf, t->name_off); |
| if (strcmp(tag_value, "user") == 0) |
| info->reg_type |= MEM_USER; |
| if (strcmp(tag_value, "percpu") == 0) |
| info->reg_type |= MEM_PERCPU; |
| } |
| |
| /* skip modifiers */ |
| while (btf_type_is_modifier(t)) { |
| info->btf_id = t->type; |
| t = btf_type_by_id(btf, t->type); |
| } |
| if (!btf_type_is_struct(t)) { |
| bpf_log(log, |
| "func '%s' arg%d type %s is not a struct\n", |
| tname, arg, btf_type_str(t)); |
| return false; |
| } |
| bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", |
| tname, arg, info->btf_id, btf_type_str(t), |
| __btf_name_by_offset(btf, t->name_off)); |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(btf_ctx_access); |
| |
| enum bpf_struct_walk_result { |
| /* < 0 error */ |
| WALK_SCALAR = 0, |
| WALK_PTR, |
| WALK_STRUCT, |
| }; |
| |
| static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, |
| const struct btf_type *t, int off, int size, |
| u32 *next_btf_id, enum bpf_type_flag *flag, |
| const char **field_name) |
| { |
| u32 i, moff, mtrue_end, msize = 0, total_nelems = 0; |
| const struct btf_type *mtype, *elem_type = NULL; |
| const struct btf_member *member; |
| const char *tname, *mname, *tag_value; |
| u32 vlen, elem_id, mid; |
| |
| again: |
| if (btf_type_is_modifier(t)) |
| t = btf_type_skip_modifiers(btf, t->type, NULL); |
| tname = __btf_name_by_offset(btf, t->name_off); |
| if (!btf_type_is_struct(t)) { |
| bpf_log(log, "Type '%s' is not a struct\n", tname); |
| return -EINVAL; |
| } |
| |
| vlen = btf_type_vlen(t); |
| if (BTF_INFO_KIND(t->info) == BTF_KIND_UNION && vlen != 1 && !(*flag & PTR_UNTRUSTED)) |
| /* |
| * walking unions yields untrusted pointers |
| * with exception of __bpf_md_ptr and other |
| * unions with a single member |
| */ |
| *flag |= PTR_UNTRUSTED; |
| |
| if (off + size > t->size) { |
| /* If the last element is a variable size array, we may |
| * need to relax the rule. |
| */ |
| struct btf_array *array_elem; |
| |
| if (vlen == 0) |
| goto error; |
| |
| member = btf_type_member(t) + vlen - 1; |
| mtype = btf_type_skip_modifiers(btf, member->type, |
| NULL); |
| if (!btf_type_is_array(mtype)) |
| goto error; |
| |
| array_elem = (struct btf_array *)(mtype + 1); |
| if (array_elem->nelems != 0) |
| goto error; |
| |
| moff = __btf_member_bit_offset(t, member) / 8; |
| if (off < moff) |
| goto error; |
| |
| /* allow structure and integer */ |
| t = btf_type_skip_modifiers(btf, array_elem->type, |
| NULL); |
| |
| if (btf_type_is_int(t)) |
| return WALK_SCALAR; |
| |
| if (!btf_type_is_struct(t)) |
| goto error; |
| |
| off = (off - moff) % t->size; |
| goto again; |
| |
| error: |
| bpf_log(log, "access beyond struct %s at off %u size %u\n", |
| tname, off, size); |
| return -EACCES; |
| } |
| |
| for_each_member(i, t, member) { |
| /* offset of the field in bytes */ |
| moff = __btf_member_bit_offset(t, member) / 8; |
| if (off + size <= moff) |
| /* won't find anything, field is already too far */ |
| break; |
| |
| if (__btf_member_bitfield_size(t, member)) { |
| u32 end_bit = __btf_member_bit_offset(t, member) + |
| __btf_member_bitfield_size(t, member); |
| |
| /* off <= moff instead of off == moff because clang |
| * does not generate a BTF member for anonymous |
| * bitfield like the ":16" here: |
| * struct { |
| * int :16; |
| * int x:8; |
| * }; |
| */ |
| if (off <= moff && |
| BITS_ROUNDUP_BYTES(end_bit) <= off + size) |
| return WALK_SCALAR; |
| |
| /* off may be accessing a following member |
| * |
| * or |
| * |
| * Doing partial access at either end of this |
| * bitfield. Continue on this case also to |
| * treat it as not accessing this bitfield |
| * and eventually error out as field not |
| * found to keep it simple. |
| * It could be relaxed if there was a legit |
| * partial access case later. |
| */ |
| continue; |
| } |
| |
| /* In case of "off" is pointing to holes of a struct */ |
| if (off < moff) |
| break; |
| |
| /* type of the field */ |
| mid = member->type; |
| mtype = btf_type_by_id(btf, member->type); |
| mname = __btf_name_by_offset(btf, member->name_off); |
| |
| mtype = __btf_resolve_size(btf, mtype, &msize, |
| &elem_type, &elem_id, &total_nelems, |
| &mid); |
| if (IS_ERR(mtype)) { |
| bpf_log(log, "field %s doesn't have size\n", mname); |
| return -EFAULT; |
| } |
| |
| mtrue_end = moff + msize; |
| if (off >= mtrue_end) |
| /* no overlap with member, keep iterating */ |
| continue; |
| |
| if (btf_type_is_array(mtype)) { |
| u32 elem_idx; |
| |
| /* __btf_resolve_size() above helps to |
| * linearize a multi-dimensional array. |
| * |
| * The logic here is treating an array |
| * in a struct as the following way: |
| * |
| * struct outer { |
| * struct inner array[2][2]; |
| * }; |
| * |
| * looks like: |
| * |
| * struct outer { |
| * struct inner array_elem0; |
| * struct inner array_elem1; |
| * struct inner array_elem2; |
| * struct inner array_elem3; |
| * }; |
| * |
| * When accessing outer->array[1][0], it moves |
| * moff to "array_elem2", set mtype to |
| * "struct inner", and msize also becomes |
| * sizeof(struct inner). Then most of the |
| * remaining logic will fall through without |
| * caring the current member is an array or |
| * not. |
| * |
| * Unlike mtype/msize/moff, mtrue_end does not |
| * change. The naming difference ("_true") tells |
| * that it is not always corresponding to |
| * the current mtype/msize/moff. |
| * It is the true end of the current |
| * member (i.e. array in this case). That |
| * will allow an int array to be accessed like |
| * a scratch space, |
| * i.e. allow access beyond the size of |
| * the array's element as long as it is |
| * within the mtrue_end boundary. |
| */ |
| |
| /* skip empty array */ |
| if (moff == mtrue_end) |
| continue; |
| |
| msize /= total_nelems; |
| elem_idx = (off - moff) / msize; |
| moff += elem_idx * msize; |
| mtype = elem_type; |
| mid = elem_id; |
| } |
| |
| /* the 'off' we're looking for is either equal to start |
| * of this field or inside of this struct |
| */ |
| if (btf_type_is_struct(mtype)) { |
| /* our field must be inside that union or struct */ |
| t = mtype; |
| |
| /* return if the offset matches the member offset */ |
| if (off == moff) { |
| *next_btf_id = mid; |
| return WALK_STRUCT; |
| } |
| |
| /* adjust offset we're looking for */ |
| off -= moff; |
| goto again; |
| } |
| |
| if (btf_type_is_ptr(mtype)) { |
| const struct btf_type *stype, *t; |
| enum bpf_type_flag tmp_flag = 0; |
| u32 id; |
| |
| if (msize != size || off != moff) { |
| bpf_log(log, |
| "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n", |
| mname, moff, tname, off, size); |
| return -EACCES; |
| } |
| |
| /* check type tag */ |
| t = btf_type_by_id(btf, mtype->type); |
| if (btf_type_is_type_tag(t)) { |
| tag_value = __btf_name_by_offset(btf, t->name_off); |
| /* check __user tag */ |
| if (strcmp(tag_value, "user") == 0) |
| tmp_flag = MEM_USER; |
| /* check __percpu tag */ |
| if (strcmp(tag_value, "percpu") == 0) |
| tmp_flag = MEM_PERCPU; |
| /* check __rcu tag */ |
| if (strcmp(tag_value, "rcu") == 0) |
| tmp_flag = MEM_RCU; |
| } |
| |
| stype = btf_type_skip_modifiers(btf, mtype->type, &id); |
| if (btf_type_is_struct(stype)) { |
| *next_btf_id = id; |
| *flag |= tmp_flag; |
| if (field_name) |
| *field_name = mname; |
| return WALK_PTR; |
| } |
| } |
| |
| /* Allow more flexible access within an int as long as |
| * it is within mtrue_end. |
| * Since mtrue_end could be the end of an array, |
| * that also allows using an array of int as a scratch |
| * space. e.g. skb->cb[]. |
| */ |
| if (off + size > mtrue_end && !(*flag & PTR_UNTRUSTED)) { |
| bpf_log(log, |
| "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n", |
| mname, mtrue_end, tname, off, size); |
| return -EACCES; |
| } |
| |
| return WALK_SCALAR; |
| } |
| bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off); |
| return -EINVAL; |
| } |
| |
| int btf_struct_access(struct bpf_verifier_log *log, |
| const struct bpf_reg_state *reg, |
| int off, int size, enum bpf_access_type atype __maybe_unused, |
| u32 *next_btf_id, enum bpf_type_flag *flag, |
| const char **field_name) |
| { |
| const struct btf *btf = reg->btf; |
| enum bpf_type_flag tmp_flag = 0; |
| const struct btf_type *t; |
| u32 id = reg->btf_id; |
| int err; |
| |
| while (type_is_alloc(reg->type)) { |
| struct btf_struct_meta *meta; |
| struct btf_record *rec; |
| int i; |
| |
| meta = btf_find_struct_meta(btf, id); |
| if (!meta) |
| break; |
| rec = meta->record; |
| for (i = 0; i < rec->cnt; i++) { |
| struct btf_field *field = &rec->fields[i]; |
| u32 offset = field->offset; |
| if (off < offset + field->size && offset < off + size) { |
| bpf_log(log, |
| "direct access to %s is disallowed\n", |
| btf_field_type_name(field->type)); |
| return -EACCES; |
| } |
| } |
| break; |
| } |
| |
| t = btf_type_by_id(btf, id); |
| do { |
| err = btf_struct_walk(log, btf, t, off, size, &id, &tmp_flag, field_name); |
| |
| switch (err) { |
| case WALK_PTR: |
| /* For local types, the destination register cannot |
| * become a pointer again. |
| */ |
| if (type_is_alloc(reg->type)) |
| return SCALAR_VALUE; |
| /* If we found the pointer or scalar on t+off, |
| * we're done. |
| */ |
| *next_btf_id = id; |
| *flag = tmp_flag; |
| return PTR_TO_BTF_ID; |
| case WALK_SCALAR: |
| return SCALAR_VALUE; |
| case WALK_STRUCT: |
| /* We found nested struct, so continue the search |
| * by diving in it. At this point the offset is |
| * aligned with the new type, so set it to 0. |
| */ |
| t = btf_type_by_id(btf, id); |
| off = 0; |
| break; |
| default: |
| /* It's either error or unknown return value.. |
| * scream and leave. |
| */ |
| if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value")) |
| return -EINVAL; |
| return err; |
| } |
| } while (t); |
| |
| return -EINVAL; |
| } |
| |
| /* Check that two BTF types, each specified as an BTF object + id, are exactly |
| * the same. Trivial ID check is not enough due to module BTFs, because we can |
| * end up with two different module BTFs, but IDs point to the common type in |
| * vmlinux BTF. |
| */ |
| bool btf_types_are_same(const struct btf *btf1, u32 id1, |
| const struct btf *btf2, u32 id2) |
| { |
| if (id1 != id2) |
| return false; |
| if (btf1 == btf2) |
| return true; |
| return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2); |
| } |
| |
| bool btf_struct_ids_match(struct bpf_verifier_log *log, |
| const struct btf *btf, u32 id, int off, |
| const struct btf *need_btf, u32 need_type_id, |
| bool strict) |
| { |
| const struct btf_type *type; |
| enum bpf_type_flag flag = 0; |
| int err; |
| |
| /* Are we already done? */ |
| if (off == 0 && btf_types_are_same(btf, id, need_btf, need_type_id)) |
| return true; |
| /* In case of strict type match, we do not walk struct, the top level |
| * type match must succeed. When strict is true, off should have already |
| * been 0. |
| */ |
| if (strict) |
| return false; |
| again: |
| type = btf_type_by_id(btf, id); |
| if (!type) |
| return false; |
| err = btf_struct_walk(log, btf, type, off, 1, &id, &flag, NULL); |
| if (err != WALK_STRUCT) |
| return false; |
| |
| /* We found nested struct object. If it matches |
| * the requested ID, we're done. Otherwise let's |
| * continue the search with offset 0 in the new |
| * type. |
| */ |
| if (!btf_types_are_same(btf, id, need_btf, need_type_id)) { |
| off = 0; |
| goto again; |
| } |
| |
| return true; |
| } |
| |
| static int __get_type_size(struct btf *btf, u32 btf_id, |
| const struct btf_type **ret_type) |
| { |
| const struct btf_type *t; |
| |
| *ret_type = btf_type_by_id(btf, 0); |
| if (!btf_id) |
| /* void */ |
| return 0; |
| t = btf_type_by_id(btf, btf_id); |
| while (t && btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| if (!t) |
| return -EINVAL; |
| *ret_type = t; |
| if (btf_type_is_ptr(t)) |
| /* kernel size of pointer. Not BPF's size of pointer*/ |
| return sizeof(void *); |
| if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) |
| return t->size; |
| return -EINVAL; |
| } |
| |
| static u8 __get_type_fmodel_flags(const struct btf_type *t) |
| { |
| u8 flags = 0; |
| |
| if (__btf_type_is_struct(t)) |
| flags |= BTF_FMODEL_STRUCT_ARG; |
| if (btf_type_is_signed_int(t)) |
| flags |= BTF_FMODEL_SIGNED_ARG; |
| |
| return flags; |
| } |
| |
| int btf_distill_func_proto(struct bpf_verifier_log *log, |
| struct btf *btf, |
| const struct btf_type *func, |
| const char *tname, |
| struct btf_func_model *m) |
| { |
| const struct btf_param *args; |
| const struct btf_type *t; |
| u32 i, nargs; |
| int ret; |
| |
| if (!func) { |
| /* BTF function prototype doesn't match the verifier types. |
| * Fall back to MAX_BPF_FUNC_REG_ARGS u64 args. |
| */ |
| for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { |
| m->arg_size[i] = 8; |
| m->arg_flags[i] = 0; |
| } |
| m->ret_size = 8; |
| m->ret_flags = 0; |
| m->nr_args = MAX_BPF_FUNC_REG_ARGS; |
| return 0; |
| } |
| args = (const struct btf_param *)(func + 1); |
| nargs = btf_type_vlen(func); |
| if (nargs > MAX_BPF_FUNC_ARGS) { |
| bpf_log(log, |
| "The function %s has %d arguments. Too many.\n", |
| tname, nargs); |
| return -EINVAL; |
| } |
| ret = __get_type_size(btf, func->type, &t); |
| if (ret < 0 || __btf_type_is_struct(t)) { |
| bpf_log(log, |
| "The function %s return type %s is unsupported.\n", |
| tname, btf_type_str(t)); |
| return -EINVAL; |
| } |
| m->ret_size = ret; |
| m->ret_flags = __get_type_fmodel_flags(t); |
| |
| for (i = 0; i < nargs; i++) { |
| if (i == nargs - 1 && args[i].type == 0) { |
| bpf_log(log, |
| "The function %s with variable args is unsupported.\n", |
| tname); |
| return -EINVAL; |
| } |
| ret = __get_type_size(btf, args[i].type, &t); |
| |
| /* No support of struct argument size greater than 16 bytes */ |
| if (ret < 0 || ret > 16) { |
| bpf_log(log, |
| "The function %s arg%d type %s is unsupported.\n", |
| tname, i, btf_type_str(t)); |
| return -EINVAL; |
| } |
| if (ret == 0) { |
| bpf_log(log, |
| "The function %s has malformed void argument.\n", |
| tname); |
| return -EINVAL; |
| } |
| m->arg_size[i] = ret; |
| m->arg_flags[i] = __get_type_fmodel_flags(t); |
| } |
| m->nr_args = nargs; |
| return 0; |
| } |
| |
| /* Compare BTFs of two functions assuming only scalars and pointers to context. |
| * t1 points to BTF_KIND_FUNC in btf1 |
| * t2 points to BTF_KIND_FUNC in btf2 |
| * Returns: |
| * EINVAL - function prototype mismatch |
| * EFAULT - verifier bug |
| * 0 - 99% match. The last 1% is validated by the verifier. |
| */ |
| static int btf_check_func_type_match(struct bpf_verifier_log *log, |
| struct btf *btf1, const struct btf_type *t1, |
| struct btf *btf2, const struct btf_type *t2) |
| { |
| const struct btf_param *args1, *args2; |
| const char *fn1, *fn2, *s1, *s2; |
| u32 nargs1, nargs2, i; |
| |
| fn1 = btf_name_by_offset(btf1, t1->name_off); |
| fn2 = btf_name_by_offset(btf2, t2->name_off); |
| |
| if (btf_func_linkage(t1) != BTF_FUNC_GLOBAL) { |
| bpf_log(log, "%s() is not a global function\n", fn1); |
| return -EINVAL; |
| } |
| if (btf_func_linkage(t2) != BTF_FUNC_GLOBAL) { |
| bpf_log(log, "%s() is not a global function\n", fn2); |
| return -EINVAL; |
| } |
| |
| t1 = btf_type_by_id(btf1, t1->type); |
| if (!t1 || !btf_type_is_func_proto(t1)) |
| return -EFAULT; |
| t2 = btf_type_by_id(btf2, t2->type); |
| if (!t2 || !btf_type_is_func_proto(t2)) |
| return -EFAULT; |
| |
| args1 = (const struct btf_param *)(t1 + 1); |
| nargs1 = btf_type_vlen(t1); |
| args2 = (const struct btf_param *)(t2 + 1); |
| nargs2 = btf_type_vlen(t2); |
| |
| if (nargs1 != nargs2) { |
| bpf_log(log, "%s() has %d args while %s() has %d args\n", |
| fn1, nargs1, fn2, nargs2); |
| return -EINVAL; |
| } |
| |
| t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); |
| t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); |
| if (t1->info != t2->info) { |
| bpf_log(log, |
| "Return type %s of %s() doesn't match type %s of %s()\n", |
| btf_type_str(t1), fn1, |
| btf_type_str(t2), fn2); |
| return -EINVAL; |
| } |
| |
| for (i = 0; i < nargs1; i++) { |
| t1 = btf_type_skip_modifiers(btf1, args1[i].type, NULL); |
| t2 = btf_type_skip_modifiers(btf2, args2[i].type, NULL); |
| |
| if (t1->info != t2->info) { |
| bpf_log(log, "arg%d in %s() is %s while %s() has %s\n", |
| i, fn1, btf_type_str(t1), |
| fn2, btf_type_str(t2)); |
| return -EINVAL; |
| } |
| if (btf_type_has_size(t1) && t1->size != t2->size) { |
| bpf_log(log, |
| "arg%d in %s() has size %d while %s() has %d\n", |
| i, fn1, t1->size, |
| fn2, t2->size); |
| return -EINVAL; |
| } |
| |
| /* global functions are validated with scalars and pointers |
| * to context only. And only global functions can be replaced. |
| * Hence type check only those types. |
| */ |
| if (btf_type_is_int(t1) || btf_is_any_enum(t1)) |
| continue; |
| if (!btf_type_is_ptr(t1)) { |
| bpf_log(log, |
| "arg%d in %s() has unrecognized type\n", |
| i, fn1); |
| return -EINVAL; |
| } |
| t1 = btf_type_skip_modifiers(btf1, t1->type, NULL); |
| t2 = btf_type_skip_modifiers(btf2, t2->type, NULL); |
| if (!btf_type_is_struct(t1)) { |
| bpf_log(log, |
| "arg%d in %s() is not a pointer to context\n", |
| i, fn1); |
| return -EINVAL; |
| } |
| if (!btf_type_is_struct(t2)) { |
| bpf_log(log, |
| "arg%d in %s() is not a pointer to context\n", |
| i, fn2); |
| return -EINVAL; |
| } |
| /* This is an optional check to make program writing easier. |
| * Compare names of structs and report an error to the user. |
| * btf_prepare_func_args() already checked that t2 struct |
| * is a context type. btf_prepare_func_args() will check |
| * later that t1 struct is a context type as well. |
| */ |
| s1 = btf_name_by_offset(btf1, t1->name_off); |
| s2 = btf_name_by_offset(btf2, t2->name_off); |
| if (strcmp(s1, s2)) { |
| bpf_log(log, |
| "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n", |
| i, fn1, s1, fn2, s2); |
| return -EINVAL; |
| } |
| } |
| return 0; |
| } |
| |
| /* Compare BTFs of given program with BTF of target program */ |
| int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog, |
| struct btf *btf2, const struct btf_type *t2) |
| { |
| struct btf *btf1 = prog->aux->btf; |
| const struct btf_type *t1; |
| u32 btf_id = 0; |
| |
| if (!prog->aux->func_info) { |
| bpf_log(log, "Program extension requires BTF\n"); |
| return -EINVAL; |
| } |
| |
| btf_id = prog->aux->func_info[0].type_id; |
| if (!btf_id) |
| return -EFAULT; |
| |
| t1 = btf_type_by_id(btf1, btf_id); |
| if (!t1 || !btf_type_is_func(t1)) |
| return -EFAULT; |
| |
| return btf_check_func_type_match(log, btf1, t1, btf2, t2); |
| } |
| |
| static bool btf_is_dynptr_ptr(const struct btf *btf, const struct btf_type *t) |
| { |
| const char *name; |
| |
| t = btf_type_by_id(btf, t->type); /* skip PTR */ |
| |
| while (btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| |
| /* allow either struct or struct forward declaration */ |
| if (btf_type_is_struct(t) || |
| (btf_type_is_fwd(t) && btf_type_kflag(t) == 0)) { |
| name = btf_str_by_offset(btf, t->name_off); |
| return name && strcmp(name, "bpf_dynptr") == 0; |
| } |
| |
| return false; |
| } |
| |
| struct bpf_cand_cache { |
| const char *name; |
| u32 name_len; |
| u16 kind; |
| u16 cnt; |
| struct { |
| const struct btf *btf; |
| u32 id; |
| } cands[]; |
| }; |
| |
| static DEFINE_MUTEX(cand_cache_mutex); |
| |
| static struct bpf_cand_cache * |
| bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id); |
| |
| static int btf_get_ptr_to_btf_id(struct bpf_verifier_log *log, int arg_idx, |
| const struct btf *btf, const struct btf_type *t) |
| { |
| struct bpf_cand_cache *cc; |
| struct bpf_core_ctx ctx = { |
| .btf = btf, |
| .log = log, |
| }; |
| u32 kern_type_id, type_id; |
| int err = 0; |
| |
| /* skip PTR and modifiers */ |
| type_id = t->type; |
| t = btf_type_by_id(btf, t->type); |
| while (btf_type_is_modifier(t)) { |
| type_id = t->type; |
| t = btf_type_by_id(btf, t->type); |
| } |
| |
| mutex_lock(&cand_cache_mutex); |
| cc = bpf_core_find_cands(&ctx, type_id); |
| if (IS_ERR(cc)) { |
| err = PTR_ERR(cc); |
| bpf_log(log, "arg#%d reference type('%s %s') candidate matching error: %d\n", |
| arg_idx, btf_type_str(t), __btf_name_by_offset(btf, t->name_off), |
| err); |
| goto cand_cache_unlock; |
| } |
| if (cc->cnt != 1) { |
| bpf_log(log, "arg#%d reference type('%s %s') %s\n", |
| arg_idx, btf_type_str(t), __btf_name_by_offset(btf, t->name_off), |
| cc->cnt == 0 ? "has no matches" : "is ambiguous"); |
| err = cc->cnt == 0 ? -ENOENT : -ESRCH; |
| goto cand_cache_unlock; |
| } |
| if (btf_is_module(cc->cands[0].btf)) { |
| bpf_log(log, "arg#%d reference type('%s %s') points to kernel module type (unsupported)\n", |
| arg_idx, btf_type_str(t), __btf_name_by_offset(btf, t->name_off)); |
| err = -EOPNOTSUPP; |
| goto cand_cache_unlock; |
| } |
| kern_type_id = cc->cands[0].id; |
| |
| cand_cache_unlock: |
| mutex_unlock(&cand_cache_mutex); |
| if (err) |
| return err; |
| |
| return kern_type_id; |
| } |
| |
| enum btf_arg_tag { |
| ARG_TAG_CTX = BIT_ULL(0), |
| ARG_TAG_NONNULL = BIT_ULL(1), |
| ARG_TAG_TRUSTED = BIT_ULL(2), |
| ARG_TAG_NULLABLE = BIT_ULL(3), |
| ARG_TAG_ARENA = BIT_ULL(4), |
| }; |
| |
| /* Process BTF of a function to produce high-level expectation of function |
| * arguments (like ARG_PTR_TO_CTX, or ARG_PTR_TO_MEM, etc). This information |
| * is cached in subprog info for reuse. |
| * Returns: |
| * EFAULT - there is a verifier bug. Abort verification. |
| * EINVAL - cannot convert BTF. |
| * 0 - Successfully processed BTF and constructed argument expectations. |
| */ |
| int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) |
| { |
| bool is_global = subprog_aux(env, subprog)->linkage == BTF_FUNC_GLOBAL; |
| struct bpf_subprog_info *sub = subprog_info(env, subprog); |
| struct bpf_verifier_log *log = &env->log; |
| struct bpf_prog *prog = env->prog; |
| enum bpf_prog_type prog_type = prog->type; |
| struct btf *btf = prog->aux->btf; |
| const struct btf_param *args; |
| const struct btf_type *t, *ref_t, *fn_t; |
| u32 i, nargs, btf_id; |
| const char *tname; |
| |
| if (sub->args_cached) |
| return 0; |
| |
| if (!prog->aux->func_info) { |
| bpf_log(log, "Verifier bug\n"); |
| return -EFAULT; |
| } |
| |
| btf_id = prog->aux->func_info[subprog].type_id; |
| if (!btf_id) { |
| if (!is_global) /* not fatal for static funcs */ |
| return -EINVAL; |
| bpf_log(log, "Global functions need valid BTF\n"); |
| return -EFAULT; |
| } |
| |
| fn_t = btf_type_by_id(btf, btf_id); |
| if (!fn_t || !btf_type_is_func(fn_t)) { |
| /* These checks were already done by the verifier while loading |
| * struct bpf_func_info |
| */ |
| bpf_log(log, "BTF of func#%d doesn't point to KIND_FUNC\n", |
| subprog); |
| return -EFAULT; |
| } |
| tname = btf_name_by_offset(btf, fn_t->name_off); |
| |
| if (prog->aux->func_info_aux[subprog].unreliable) { |
| bpf_log(log, "Verifier bug in function %s()\n", tname); |
| return -EFAULT; |
| } |
| if (prog_type == BPF_PROG_TYPE_EXT) |
| prog_type = prog->aux->dst_prog->type; |
| |
| t = btf_type_by_id(btf, fn_t->type); |
| if (!t || !btf_type_is_func_proto(t)) { |
| bpf_log(log, "Invalid type of function %s()\n", tname); |
| return -EFAULT; |
| } |
| args = (const struct btf_param *)(t + 1); |
| nargs = btf_type_vlen(t); |
| if (nargs > MAX_BPF_FUNC_REG_ARGS) { |
| if (!is_global) |
| return -EINVAL; |
| bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", |
| tname, nargs, MAX_BPF_FUNC_REG_ARGS); |
| return -EINVAL; |
| } |
| /* check that function returns int, exception cb also requires this */ |
| t = btf_type_by_id(btf, t->type); |
| while (btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { |
| if (!is_global) |
| return -EINVAL; |
| bpf_log(log, |
| "Global function %s() doesn't return scalar. Only those are supported.\n", |
| tname); |
| return -EINVAL; |
| } |
| /* Convert BTF function arguments into verifier types. |
| * Only PTR_TO_CTX and SCALAR are supported atm. |
| */ |
| for (i = 0; i < nargs; i++) { |
| u32 tags = 0; |
| int id = 0; |
| |
| /* 'arg:<tag>' decl_tag takes precedence over derivation of |
| * register type from BTF type itself |
| */ |
| while ((id = btf_find_next_decl_tag(btf, fn_t, i, "arg:", id)) > 0) { |
| const struct btf_type *tag_t = btf_type_by_id(btf, id); |
| const char *tag = __btf_name_by_offset(btf, tag_t->name_off) + 4; |
| |
| /* disallow arg tags in static subprogs */ |
| if (!is_global) { |
| bpf_log(log, "arg#%d type tag is not supported in static functions\n", i); |
| return -EOPNOTSUPP; |
| } |
| |
| if (strcmp(tag, "ctx") == 0) { |
| tags |= ARG_TAG_CTX; |
| } else if (strcmp(tag, "trusted") == 0) { |
| tags |= ARG_TAG_TRUSTED; |
| } else if (strcmp(tag, "nonnull") == 0) { |
| tags |= ARG_TAG_NONNULL; |
| } else if (strcmp(tag, "nullable") == 0) { |
| tags |= ARG_TAG_NULLABLE; |
| } else if (strcmp(tag, "arena") == 0) { |
| tags |= ARG_TAG_ARENA; |
| } else { |
| bpf_log(log, "arg#%d has unsupported set of tags\n", i); |
| return -EOPNOTSUPP; |
| } |
| } |
| if (id != -ENOENT) { |
| bpf_log(log, "arg#%d type tag fetching failure: %d\n", i, id); |
| return id; |
| } |
| |
| t = btf_type_by_id(btf, args[i].type); |
| while (btf_type_is_modifier(t)) |
| t = btf_type_by_id(btf, t->type); |
| if (!btf_type_is_ptr(t)) |
| goto skip_pointer; |
| |
| if ((tags & ARG_TAG_CTX) || btf_is_prog_ctx_type(log, btf, t, prog_type, i)) { |
| if (tags & ~ARG_TAG_CTX) { |
| bpf_log(log, "arg#%d has invalid combination of tags\n", i); |
| return -EINVAL; |
| } |
| if ((tags & ARG_TAG_CTX) && |
| btf_validate_prog_ctx_type(log, btf, t, i, prog_type, |
| prog->expected_attach_type)) |
| return -EINVAL; |
| sub->args[i].arg_type = ARG_PTR_TO_CTX; |
| continue; |
| } |
| if (btf_is_dynptr_ptr(btf, t)) { |
| if (tags) { |
| bpf_log(log, "arg#%d has invalid combination of tags\n", i); |
| return -EINVAL; |
| } |
| sub->args[i].arg_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY; |
| continue; |
| } |
| if (tags & ARG_TAG_TRUSTED) { |
| int kern_type_id; |
| |
| if (tags & ARG_TAG_NONNULL) { |
| bpf_log(log, "arg#%d has invalid combination of tags\n", i); |
| return -EINVAL; |
| } |
| |
| kern_type_id = btf_get_ptr_to_btf_id(log, i, btf, t); |
| if (kern_type_id < 0) |
| return kern_type_id; |
| |
| sub->args[i].arg_type = ARG_PTR_TO_BTF_ID | PTR_TRUSTED; |
| if (tags & ARG_TAG_NULLABLE) |
| sub->args[i].arg_type |= PTR_MAYBE_NULL; |
| sub->args[i].btf_id = kern_type_id; |
| continue; |
| } |
| if (tags & ARG_TAG_ARENA) { |
| if (tags & ~ARG_TAG_ARENA) { |
| bpf_log(log, "arg#%d arena cannot be combined with any other tags\n", i); |
| return -EINVAL; |
| } |
| sub->args[i].arg_type = ARG_PTR_TO_ARENA; |
| continue; |
| } |
| if (is_global) { /* generic user data pointer */ |
| u32 mem_size; |
| |
| if (tags & ARG_TAG_NULLABLE) { |
| bpf_log(log, "arg#%d has invalid combination of tags\n", i); |
| return -EINVAL; |
| } |
| |
| t = btf_type_skip_modifiers(btf, t->type, NULL); |
| ref_t = btf_resolve_size(btf, t, &mem_size); |
| if (IS_ERR(ref_t)) { |
| bpf_log(log, "arg#%d reference type('%s %s') size cannot be determined: %ld\n", |
| i, btf_type_str(t), btf_name_by_offset(btf, t->name_off), |
| PTR_ERR(ref_t)); |
| return -EINVAL; |
| } |
| |
| sub->args[i].arg_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL; |
| if (tags & ARG_TAG_NONNULL) |
| sub->args[i].arg_type &= ~PTR_MAYBE_NULL; |
| sub->args[i].mem_size = mem_size; |
| continue; |
| } |
| |
| skip_pointer: |
| if (tags) { |
| bpf_log(log, "arg#%d has pointer tag, but is not a pointer type\n", i); |
| return -EINVAL; |
| } |
| if (btf_type_is_int(t) || btf_is_any_enum(t)) { |
| sub->args[i].arg_type = ARG_ANYTHING; |
| continue; |
| } |
| if (!is_global) |
| return -EINVAL; |
| bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", |
| i, btf_type_str(t), tname); |
| return -EINVAL; |
| } |
| |
| sub->arg_cnt = nargs; |
| sub->args_cached = true; |
| |
| return 0; |
| } |
| |
| static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, |
| struct btf_show *show) |
| { |
| const struct btf_type *t = btf_type_by_id(btf, type_id); |
| |
| show->btf = btf; |
| memset(&show->state, 0, sizeof(show->state)); |
| memset(&show->obj, 0, sizeof(show->obj)); |
| |
| btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); |
| } |
| |
| __printf(2, 0) static void btf_seq_show(struct btf_show *show, const char *fmt, |
| va_list args) |
| { |
| seq_vprintf((struct seq_file *)show->target, fmt, args); |
| } |
| |
| int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, |
| void *obj, struct seq_file *m, u64 flags) |
| { |
| struct btf_show sseq; |
| |
| sseq.target = m; |
| sseq.showfn = btf_seq_show; |
| sseq.flags = flags; |
| |
| btf_type_show(btf, type_id, obj, &sseq); |
| |
| return sseq.state.status; |
| } |
| |
| void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, |
| struct seq_file *m) |
| { |
| (void) btf_type_seq_show_flags(btf, type_id, obj, m, |
| BTF_SHOW_NONAME | BTF_SHOW_COMPACT | |
| BTF_SHOW_ZERO | BTF_SHOW_UNSAFE); |
| } |
| |
| struct btf_show_snprintf { |
| struct btf_show show; |
| int len_left; /* space left in string */ |
| int len; /* length we would have written */ |
| }; |
| |
| __printf(2, 0) static void btf_snprintf_show(struct btf_show *show, const char *fmt, |
| va_list args) |
| { |
| struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; |
| int len; |
| |
| len = vsnprintf(show->target, ssnprintf->len_left, fmt, args); |
| |
| if (len < 0) { |
| ssnprintf->len_left = 0; |
| ssnprintf->len = len; |
| } else if (len >= ssnprintf->len_left) { |
| /* no space, drive on to get length we would have written */ |
| ssnprintf->len_left = 0; |
| ssnprintf->len += len; |
| } else { |
| ssnprintf->len_left -= len; |
| ssnprintf->len += len; |
| show->target += len; |
| } |
| } |
| |
| int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj, |
| char *buf, int len, u64 flags) |
| { |
| struct btf_show_snprintf ssnprintf; |
| |
| ssnprintf.show.target = buf; |
| ssnprintf.show.flags = flags; |
| ssnprintf.show.showfn = btf_snprintf_show; |
| ssnprintf.len_left = len; |
| ssnprintf.len = 0; |
| |
| btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf); |
| |
| /* If we encountered an error, return it. */ |
| if (ssnprintf.show.state.status) |
| return ssnprintf.show.state.status; |
| |
| /* Otherwise return length we would have written */ |
| return ssnprintf.len; |
| } |
| |
| #ifdef CONFIG_PROC_FS |
| static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) |
| { |
| const struct btf *btf = filp->private_data; |
| |
| seq_printf(m, "btf_id:\t%u\n", btf->id); |
| } |
| #endif |
| |
| static int btf_release(struct inode *inode, struct file *filp) |
| { |
| btf_put(filp->private_data); |
| return 0; |
| } |
| |
| const struct file_operations btf_fops = { |
| #ifdef CONFIG_PROC_FS |
| .show_fdinfo = bpf_btf_show_fdinfo, |
| #endif |
| .release = btf_release, |
| }; |
| |
| static int __btf_new_fd(struct btf *btf) |
| { |
| return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); |
| } |
| |
| int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) |
| { |
| struct btf *btf; |
| int ret; |
| |
| btf = btf_parse(attr, uattr, uattr_size); |
| if (IS_ERR(btf)) |
| return PTR_ERR(btf); |
| |
| ret = btf_alloc_id(btf); |
| if (ret) { |
| btf_free(btf); |
| return ret; |
| } |
| |
| /* |
| * The BTF ID is published to the userspace. |
| * All BTF free must go through call_rcu() from |
| * now on (i.e. free by calling btf_put()). |
| */ |
| |
| ret = __btf_new_fd(btf); |
| if (ret < 0) |
| btf_put(btf); |
| |
| return ret; |
| } |
| |
| struct btf *btf_get_by_fd(int fd) |
| { |
| struct btf *btf; |
| CLASS(fd, f)(fd); |
| |
| if (fd_empty(f)) |
| return ERR_PTR(-EBADF); |
| |
| if (fd_file(f)->f_op != &btf_fops) |
| return ERR_PTR(-EINVAL); |
| |
| btf = fd_file(f)->private_data; |
| refcount_inc(&btf->refcnt); |
| |
| return btf; |
| } |
| |
| int btf_get_info_by_fd(const struct btf *btf, |
| const union bpf_attr *attr, |
| union bpf_attr __user *uattr) |
| { |
| struct bpf_btf_info __user *uinfo; |
| struct bpf_btf_info info; |
| u32 info_copy, btf_copy; |
| void __user *ubtf; |
| char __user *uname; |
| u32 uinfo_len, uname_len, name_len; |
| int ret = 0; |
| |
| uinfo = u64_to_user_ptr(attr->info.info); |
| uinfo_len = attr->info.info_len; |
| |
| info_copy = min_t(u32, uinfo_len, sizeof(info)); |
| memset(&info, 0, sizeof(info)); |
| if (copy_from_user(&info, uinfo, info_copy)) |
| return -EFAULT; |
| |
| info.id = btf->id; |
| ubtf = u64_to_user_ptr(info.btf); |
| btf_copy = min_t(u32, btf->data_size, info.btf_size); |
| if (copy_to_user(ubtf, btf->data, btf_copy)) |
| return -EFAULT; |
| info.btf_size = btf->data_size; |
| |
| info.kernel_btf = btf->kernel_btf; |
| |
| uname = u64_to_user_ptr(info.name); |
| uname_len = info.name_len; |
| if (!uname ^ !uname_len) |
| return -EINVAL; |
| |
| name_len = strlen(btf->name); |
| info.name_len = name_len; |
| |
| if (uname) { |
| if (uname_len >= name_len + 1) { |
| if (copy_to_user(uname, btf->name, name_len + 1)) |
| return -EFAULT; |
| } else { |
| char zero = '\0'; |
| |
| if (copy_to_user(uname, btf->name, uname_len - 1)) |
| return -EFAULT; |
| if (put_user(zero, uname + uname_len - 1)) |
| return -EFAULT; |
| /* let user-space know about too short buffer */ |
| ret = -ENOSPC; |
| } |
| } |
| |
| if (copy_to_user(uinfo, &info, info_copy) || |
| put_user(info_copy, &uattr->info.info_len)) |
| return -EFAULT; |
| |
| return ret; |
| } |
| |
| int btf_get_fd_by_id(u32 id) |
| { |
| struct btf *btf; |
| int fd; |
| |
| rcu_read_lock(); |
| btf = idr_find(&btf_idr, id); |
| if (!btf || !refcount_inc_not_zero(&btf->refcnt)) |
| btf = ERR_PTR(-ENOENT); |
| rcu_read_unlock(); |
| |
| if (IS_ERR(btf)) |
| return PTR_ERR(btf); |
| |
| fd = __btf_new_fd(btf); |
| if (fd < 0) |
| btf_put(btf); |
| |
| return fd; |
| } |
| |
| u32 btf_obj_id(const struct btf *btf) |
| { |
| return btf->id; |
| } |
| |
| bool btf_is_kernel(const struct btf *btf) |
| { |
| return btf->kernel_btf; |
| } |
| |
| bool btf_is_module(const struct btf *btf) |
| { |
| return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0; |
| } |
| |
| enum { |
| BTF_MODULE_F_LIVE = (1 << 0), |
| }; |
| |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| struct btf_module { |
| struct list_head list; |
| struct module *module; |
| struct btf *btf; |
| struct bin_attribute *sysfs_attr; |
| int flags; |
| }; |
| |
| static LIST_HEAD(btf_modules); |
| static DEFINE_MUTEX(btf_module_mutex); |
| |
| static ssize_t |
| btf_module_read(struct file *file, struct kobject *kobj, |
| struct bin_attribute *bin_attr, |
| char *buf, loff_t off, size_t len) |
| { |
| const struct btf *btf = bin_attr->private; |
| |
| memcpy(buf, btf->data + off, len); |
| return len; |
| } |
| |
| static void purge_cand_cache(struct btf *btf); |
| |
| static int btf_module_notify(struct notifier_block *nb, unsigned long op, |
| void *module) |
| { |
| struct btf_module *btf_mod, *tmp; |
| struct module *mod = module; |
| struct btf *btf; |
| int err = 0; |
| |
| if (mod->btf_data_size == 0 || |
| (op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE && |
| op != MODULE_STATE_GOING)) |
| goto out; |
| |
| switch (op) { |
| case MODULE_STATE_COMING: |
| btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL); |
| if (!btf_mod) { |
| err = -ENOMEM; |
| goto out; |
| } |
| btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size, |
| mod->btf_base_data, mod->btf_base_data_size); |
| if (IS_ERR(btf)) { |
| kfree(btf_mod); |
| if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) { |
| pr_warn("failed to validate module [%s] BTF: %ld\n", |
| mod->name, PTR_ERR(btf)); |
| err = PTR_ERR(btf); |
| } else { |
| pr_warn_once("Kernel module BTF mismatch detected, BTF debug info may be unavailable for some modules\n"); |
| } |
| goto out; |
| } |
| err = btf_alloc_id(btf); |
| if (err) { |
| btf_free(btf); |
| kfree(btf_mod); |
| goto out; |
| } |
| |
| purge_cand_cache(NULL); |
| mutex_lock(&btf_module_mutex); |
| btf_mod->module = module; |
| btf_mod->btf = btf; |
| list_add(&btf_mod->list, &btf_modules); |
| mutex_unlock(&btf_module_mutex); |
| |
| if (IS_ENABLED(CONFIG_SYSFS)) { |
| struct bin_attribute *attr; |
| |
| attr = kzalloc(sizeof(*attr), GFP_KERNEL); |
| if (!attr) |
| goto out; |
| |
| sysfs_bin_attr_init(attr); |
| attr->attr.name = btf->name; |
| attr->attr.mode = 0444; |
| attr->size = btf->data_size; |
| attr->private = btf; |
| attr->read = btf_module_read; |
| |
| err = sysfs_create_bin_file(btf_kobj, attr); |
| if (err) { |
| pr_warn("failed to register module [%s] BTF in sysfs: %d\n", |
| mod->name, err); |
| kfree(attr); |
| err = 0; |
| goto out; |
| } |
| |
| btf_mod->sysfs_attr = attr; |
| } |
| |
| break; |
| case MODULE_STATE_LIVE: |
| mutex_lock(&btf_module_mutex); |
| list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| if (btf_mod->module != module) |
| continue; |
| |
| btf_mod->flags |= BTF_MODULE_F_LIVE; |
| break; |
| } |
| mutex_unlock(&btf_module_mutex); |
| break; |
| case MODULE_STATE_GOING: |
| mutex_lock(&btf_module_mutex); |
| list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| if (btf_mod->module != module) |
| continue; |
| |
| list_del(&btf_mod->list); |
| if (btf_mod->sysfs_attr) |
| sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr); |
| purge_cand_cache(btf_mod->btf); |
| btf_put(btf_mod->btf); |
| kfree(btf_mod->sysfs_attr); |
| kfree(btf_mod); |
| break; |
| } |
| mutex_unlock(&btf_module_mutex); |
| break; |
| } |
| out: |
| return notifier_from_errno(err); |
| } |
| |
| static struct notifier_block btf_module_nb = { |
| .notifier_call = btf_module_notify, |
| }; |
| |
| static int __init btf_module_init(void) |
| { |
| register_module_notifier(&btf_module_nb); |
| return 0; |
| } |
| |
| fs_initcall(btf_module_init); |
| #endif /* CONFIG_DEBUG_INFO_BTF_MODULES */ |
| |
| struct module *btf_try_get_module(const struct btf *btf) |
| { |
| struct module *res = NULL; |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| struct btf_module *btf_mod, *tmp; |
| |
| mutex_lock(&btf_module_mutex); |
| list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| if (btf_mod->btf != btf) |
| continue; |
| |
| /* We must only consider module whose __init routine has |
| * finished, hence we must check for BTF_MODULE_F_LIVE flag, |
| * which is set from the notifier callback for |
| * MODULE_STATE_LIVE. |
| */ |
| if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module)) |
| res = btf_mod->module; |
| |
| break; |
| } |
| mutex_unlock(&btf_module_mutex); |
| #endif |
| |
| return res; |
| } |
| |
| /* Returns struct btf corresponding to the struct module. |
| * This function can return NULL or ERR_PTR. |
| */ |
| static struct btf *btf_get_module_btf(const struct module *module) |
| { |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| struct btf_module *btf_mod, *tmp; |
| #endif |
| struct btf *btf = NULL; |
| |
| if (!module) { |
| btf = bpf_get_btf_vmlinux(); |
| if (!IS_ERR_OR_NULL(btf)) |
| btf_get(btf); |
| return btf; |
| } |
| |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| mutex_lock(&btf_module_mutex); |
| list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) { |
| if (btf_mod->module != module) |
| continue; |
| |
| btf_get(btf_mod->btf); |
| btf = btf_mod->btf; |
| break; |
| } |
| mutex_unlock(&btf_module_mutex); |
| #endif |
| |
| return btf; |
| } |
| |
| static int check_btf_kconfigs(const struct module *module, const char *feature) |
| { |
| if (!module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { |
| pr_err("missing vmlinux BTF, cannot register %s\n", feature); |
| return -ENOENT; |
| } |
| if (module && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) |
| pr_warn("missing module BTF, cannot register %s\n", feature); |
| return 0; |
| } |
| |
| BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) |
| { |
| struct btf *btf = NULL; |
| int btf_obj_fd = 0; |
| long ret; |
| |
| if (flags) |
| return -EINVAL; |
| |
| if (name_sz <= 1 || name[name_sz - 1]) |
| return -EINVAL; |
| |
| ret = bpf_find_btf_id(name, kind, &btf); |
| if (ret > 0 && btf_is_module(btf)) { |
| btf_obj_fd = __btf_new_fd(btf); |
| if (btf_obj_fd < 0) { |
| btf_put(btf); |
| return btf_obj_fd; |
| } |
| return ret | (((u64)btf_obj_fd) << 32); |
| } |
| if (ret > 0) |
| btf_put(btf); |
| return ret; |
| } |
| |
| const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { |
| .func = bpf_btf_find_by_name_kind, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg2_type = ARG_CONST_SIZE, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE) |
| #define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type) |
| BTF_TRACING_TYPE_xxx |
| #undef BTF_TRACING_TYPE |
| |
| /* Validate well-formedness of iter argument type. |
| * On success, return positive BTF ID of iter state's STRUCT type. |
| * On error, negative error is returned. |
| */ |
| int btf_check_iter_arg(struct btf *btf, const struct btf_type *func, int arg_idx) |
| { |
| const struct btf_param *arg; |
| const struct btf_type *t; |
| const char *name; |
| int btf_id; |
| |
| if (btf_type_vlen(func) <= arg_idx) |
| return -EINVAL; |
| |
| arg = &btf_params(func)[arg_idx]; |
| t = btf_type_skip_modifiers(btf, arg->type, NULL); |
| if (!t || !btf_type_is_ptr(t)) |
| return -EINVAL; |
| t = btf_type_skip_modifiers(btf, t->type, &btf_id); |
| if (!t || !__btf_type_is_struct(t)) |
| return -EINVAL; |
| |
| name = btf_name_by_offset(btf, t->name_off); |
| if (!name || strncmp(name, ITER_PREFIX, sizeof(ITER_PREFIX) - 1)) |
| return -EINVAL; |
| |
| return btf_id; |
| } |
| |
| static int btf_check_iter_kfuncs(struct btf *btf, const char *func_name, |
| const struct btf_type *func, u32 func_flags) |
| { |
| u32 flags = func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY); |
| const char *sfx, *iter_name; |
| const struct btf_type *t; |
| char exp_name[128]; |
| u32 nr_args; |
| int btf_id; |
| |
| /* exactly one of KF_ITER_{NEW,NEXT,DESTROY} can be set */ |
| if (!flags || (flags & (flags - 1))) |
| return -EINVAL; |
| |
| /* any BPF iter kfunc should have `struct bpf_iter_<type> *` first arg */ |
| nr_args = btf_type_vlen(func); |
| if (nr_args < 1) |
| return -EINVAL; |
| |
| btf_id = btf_check_iter_arg(btf, func, 0); |
| if (btf_id < 0) |
| return btf_id; |
| |
| /* sizeof(struct bpf_iter_<type>) should be a multiple of 8 to |
| * fit nicely in stack slots |
| */ |
| t = btf_type_by_id(btf, btf_id); |
| if (t->size == 0 || (t->size % 8)) |
| return -EINVAL; |
| |
| /* validate bpf_iter_<type>_{new,next,destroy}(struct bpf_iter_<type> *) |
| * naming pattern |
| */ |
| iter_name = btf_name_by_offset(btf, t->name_off) + sizeof(ITER_PREFIX) - 1; |
| if (flags & KF_ITER_NEW) |
| sfx = "new"; |
| else if (flags & KF_ITER_NEXT) |
| sfx = "next"; |
| else /* (flags & KF_ITER_DESTROY) */ |
| sfx = "destroy"; |
| |
| snprintf(exp_name, sizeof(exp_name), "bpf_iter_%s_%s", iter_name, sfx); |
| if (strcmp(func_name, exp_name)) |
| return -EINVAL; |
| |
| /* only iter constructor should have extra arguments */ |
| if (!(flags & KF_ITER_NEW) && nr_args != 1) |
| return -EINVAL; |
| |
| if (flags & KF_ITER_NEXT) { |
| /* bpf_iter_<type>_next() should return pointer */ |
| t = btf_type_skip_modifiers(btf, func->type, NULL); |
| if (!t || !btf_type_is_ptr(t)) |
| return -EINVAL; |
| } |
| |
| if (flags & KF_ITER_DESTROY) { |
| /* bpf_iter_<type>_destroy() should return void */ |
| t = btf_type_by_id(btf, func->type); |
| if (!t || !btf_type_is_void(t)) |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_check_kfunc_protos(struct btf *btf, u32 func_id, u32 func_flags) |
| { |
| const struct btf_type *func; |
| const char *func_name; |
| int err; |
| |
| /* any kfunc should be FUNC -> FUNC_PROTO */ |
| func = btf_type_by_id(btf, func_id); |
| if (!func || !btf_type_is_func(func)) |
| return -EINVAL; |
| |
| /* sanity check kfunc name */ |
| func_name = btf_name_by_offset(btf, func->name_off); |
| if (!func_name || !func_name[0]) |
| return -EINVAL; |
| |
| func = btf_type_by_id(btf, func->type); |
| if (!func || !btf_type_is_func_proto(func)) |
| return -EINVAL; |
| |
| if (func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY)) { |
| err = btf_check_iter_kfuncs(btf, func_name, func, func_flags); |
| if (err) |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| /* Kernel Function (kfunc) BTF ID set registration API */ |
| |
| static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook, |
| const struct btf_kfunc_id_set *kset) |
| { |
| struct btf_kfunc_hook_filter *hook_filter; |
| struct btf_id_set8 *add_set = kset->set; |
| bool vmlinux_set = !btf_is_module(btf); |
| bool add_filter = !!kset->filter; |
| struct btf_kfunc_set_tab *tab; |
| struct btf_id_set8 *set; |
| u32 set_cnt, i; |
| int ret; |
| |
| if (hook >= BTF_KFUNC_HOOK_MAX) { |
| ret = -EINVAL; |
| goto end; |
| } |
| |
| if (!add_set->cnt) |
| return 0; |
| |
| tab = btf->kfunc_set_tab; |
| |
| if (tab && add_filter) { |
| u32 i; |
| |
| hook_filter = &tab->hook_filters[hook]; |
| for (i = 0; i < hook_filter->nr_filters; i++) { |
| if (hook_filter->filters[i] == kset->filter) { |
| add_filter = false; |
| break; |
| } |
| } |
| |
| if (add_filter && hook_filter->nr_filters == BTF_KFUNC_FILTER_MAX_CNT) { |
| ret = -E2BIG; |
| goto end; |
| } |
| } |
| |
| if (!tab) { |
| tab = kzalloc(sizeof(*tab), GFP_KERNEL | __GFP_NOWARN); |
| if (!tab) |
| return -ENOMEM; |
| btf->kfunc_set_tab = tab; |
| } |
| |
| set = tab->sets[hook]; |
| /* Warn when register_btf_kfunc_id_set is called twice for the same hook |
| * for module sets. |
| */ |
| if (WARN_ON_ONCE(set && !vmlinux_set)) { |
| ret = -EINVAL; |
| goto end; |
| } |
| |
| /* In case of vmlinux sets, there may be more than one set being |
| * registered per hook. To create a unified set, we allocate a new set |
| * and concatenate all individual sets being registered. While each set |
| * is individually sorted, they may become unsorted when concatenated, |
| * hence re-sorting the final set again is required to make binary |
| * searching the set using btf_id_set8_contains function work. |
| * |
| * For module sets, we need to allocate as we may need to relocate |
| * BTF ids. |
| */ |
| set_cnt = set ? set->cnt : 0; |
| |
| if (set_cnt > U32_MAX - add_set->cnt) { |
| ret = -EOVERFLOW; |
| goto end; |
| } |
| |
| if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) { |
| ret = -E2BIG; |
| goto end; |
| } |
| |
| /* Grow set */ |
| set = krealloc(tab->sets[hook], |
| offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!set) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| |
| /* For newly allocated set, initialize set->cnt to 0 */ |
| if (!tab->sets[hook]) |
| set->cnt = 0; |
| tab->sets[hook] = set; |
| |
| /* Concatenate the two sets */ |
| memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0])); |
| /* Now that the set is copied, update with relocated BTF ids */ |
| for (i = set->cnt; i < set->cnt + add_set->cnt; i++) |
| set->pairs[i].id = btf_relocate_id(btf, set->pairs[i].id); |
| |
| set->cnt += add_set->cnt; |
| |
| sort(set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func, NULL); |
| |
| if (add_filter) { |
| hook_filter = &tab->hook_filters[hook]; |
| hook_filter->filters[hook_filter->nr_filters++] = kset->filter; |
| } |
| return 0; |
| end: |
| btf_free_kfunc_set_tab(btf); |
| return ret; |
| } |
| |
| static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, |
| enum btf_kfunc_hook hook, |
| u32 kfunc_btf_id, |
| const struct bpf_prog *prog) |
| { |
| struct btf_kfunc_hook_filter *hook_filter; |
| struct btf_id_set8 *set; |
| u32 *id, i; |
| |
| if (hook >= BTF_KFUNC_HOOK_MAX) |
| return NULL; |
| if (!btf->kfunc_set_tab) |
| return NULL; |
| hook_filter = &btf->kfunc_set_tab->hook_filters[hook]; |
| for (i = 0; i < hook_filter->nr_filters; i++) { |
| if (hook_filter->filters[i](prog, kfunc_btf_id)) |
| return NULL; |
| } |
| set = btf->kfunc_set_tab->sets[hook]; |
| if (!set) |
| return NULL; |
| id = btf_id_set8_contains(set, kfunc_btf_id); |
| if (!id) |
| return NULL; |
| /* The flags for BTF ID are located next to it */ |
| return id + 1; |
| } |
| |
| static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) |
| { |
| switch (prog_type) { |
| case BPF_PROG_TYPE_UNSPEC: |
| return BTF_KFUNC_HOOK_COMMON; |
| case BPF_PROG_TYPE_XDP: |
| return BTF_KFUNC_HOOK_XDP; |
| case BPF_PROG_TYPE_SCHED_CLS: |
| return BTF_KFUNC_HOOK_TC; |
| case BPF_PROG_TYPE_STRUCT_OPS: |
| return BTF_KFUNC_HOOK_STRUCT_OPS; |
| case BPF_PROG_TYPE_TRACING: |
| case BPF_PROG_TYPE_TRACEPOINT: |
| case BPF_PROG_TYPE_PERF_EVENT: |
| case BPF_PROG_TYPE_LSM: |
| return BTF_KFUNC_HOOK_TRACING; |
| case BPF_PROG_TYPE_SYSCALL: |
| return BTF_KFUNC_HOOK_SYSCALL; |
| case BPF_PROG_TYPE_CGROUP_SKB: |
| case BPF_PROG_TYPE_CGROUP_SOCK: |
| case BPF_PROG_TYPE_CGROUP_DEVICE: |
| case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: |
| case BPF_PROG_TYPE_CGROUP_SOCKOPT: |
| case BPF_PROG_TYPE_CGROUP_SYSCTL: |
| return BTF_KFUNC_HOOK_CGROUP; |
| case BPF_PROG_TYPE_SCHED_ACT: |
| return BTF_KFUNC_HOOK_SCHED_ACT; |
| case BPF_PROG_TYPE_SK_SKB: |
| return BTF_KFUNC_HOOK_SK_SKB; |
| case BPF_PROG_TYPE_SOCKET_FILTER: |
| return BTF_KFUNC_HOOK_SOCKET_FILTER; |
| case BPF_PROG_TYPE_LWT_OUT: |
| case BPF_PROG_TYPE_LWT_IN: |
| case BPF_PROG_TYPE_LWT_XMIT: |
| case BPF_PROG_TYPE_LWT_SEG6LOCAL: |
| return BTF_KFUNC_HOOK_LWT; |
| case BPF_PROG_TYPE_NETFILTER: |
| return BTF_KFUNC_HOOK_NETFILTER; |
| case BPF_PROG_TYPE_KPROBE: |
| return BTF_KFUNC_HOOK_KPROBE; |
| default: |
| return BTF_KFUNC_HOOK_MAX; |
| } |
| } |
| |
| /* Caution: |
| * Reference to the module (obtained using btf_try_get_module) corresponding to |
| * the struct btf *MUST* be held when calling this function from verifier |
| * context. This is usually true as we stash references in prog's kfunc_btf_tab; |
| * keeping the reference for the duration of the call provides the necessary |
| * protection for looking up a well-formed btf->kfunc_set_tab. |
| */ |
| u32 *btf_kfunc_id_set_contains(const struct btf *btf, |
| u32 kfunc_btf_id, |
| const struct bpf_prog *prog) |
| { |
| enum bpf_prog_type prog_type = resolve_prog_type(prog); |
| enum btf_kfunc_hook hook; |
| u32 *kfunc_flags; |
| |
| kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id, prog); |
| if (kfunc_flags) |
| return kfunc_flags; |
| |
| hook = bpf_prog_type_to_kfunc_hook(prog_type); |
| return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id, prog); |
| } |
| |
| u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id, |
| const struct bpf_prog *prog) |
| { |
| return __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id, prog); |
| } |
| |
| static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, |
| const struct btf_kfunc_id_set *kset) |
| { |
| struct btf *btf; |
| int ret, i; |
| |
| btf = btf_get_module_btf(kset->owner); |
| if (!btf) |
| return check_btf_kconfigs(kset->owner, "kfunc"); |
| if (IS_ERR(btf)) |
| return PTR_ERR(btf); |
| |
| for (i = 0; i < kset->set->cnt; i++) { |
| ret = btf_check_kfunc_protos(btf, btf_relocate_id(btf, kset->set->pairs[i].id), |
| kset->set->pairs[i].flags); |
| if (ret) |
| goto err_out; |
| } |
| |
| ret = btf_populate_kfunc_set(btf, hook, kset); |
| |
| err_out: |
| btf_put(btf); |
| return ret; |
| } |
| |
| /* This function must be invoked only from initcalls/module init functions */ |
| int register_btf_kfunc_id_set(enum bpf_prog_type prog_type, |
| const struct btf_kfunc_id_set *kset) |
| { |
| enum btf_kfunc_hook hook; |
| |
| /* All kfuncs need to be tagged as such in BTF. |
| * WARN() for initcall registrations that do not check errors. |
| */ |
| if (!(kset->set->flags & BTF_SET8_KFUNCS)) { |
| WARN_ON(!kset->owner); |
| return -EINVAL; |
| } |
| |
| hook = bpf_prog_type_to_kfunc_hook(prog_type); |
| return __register_btf_kfunc_id_set(hook, kset); |
| } |
| EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set); |
| |
| /* This function must be invoked only from initcalls/module init functions */ |
| int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset) |
| { |
| return __register_btf_kfunc_id_set(BTF_KFUNC_HOOK_FMODRET, kset); |
| } |
| EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set); |
| |
| s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id) |
| { |
| struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab; |
| struct btf_id_dtor_kfunc *dtor; |
| |
| if (!tab) |
| return -ENOENT; |
| /* Even though the size of tab->dtors[0] is > sizeof(u32), we only need |
| * to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func. |
| */ |
| BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0); |
| dtor = bsearch(&btf_id, tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func); |
| if (!dtor) |
| return -ENOENT; |
| return dtor->kfunc_btf_id; |
| } |
| |
| static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt) |
| { |
| const struct btf_type *dtor_func, *dtor_func_proto, *t; |
| const struct btf_param *args; |
| s32 dtor_btf_id; |
| u32 nr_args, i; |
| |
| for (i = 0; i < cnt; i++) { |
| dtor_btf_id = btf_relocate_id(btf, dtors[i].kfunc_btf_id); |
| |
| dtor_func = btf_type_by_id(btf, dtor_btf_id); |
| if (!dtor_func || !btf_type_is_func(dtor_func)) |
| return -EINVAL; |
| |
| dtor_func_proto = btf_type_by_id(btf, dtor_func->type); |
| if (!dtor_func_proto || !btf_type_is_func_proto(dtor_func_proto)) |
| return -EINVAL; |
| |
| /* Make sure the prototype of the destructor kfunc is 'void func(type *)' */ |
| t = btf_type_by_id(btf, dtor_func_proto->type); |
| if (!t || !btf_type_is_void(t)) |
| return -EINVAL; |
| |
| nr_args = btf_type_vlen(dtor_func_proto); |
| if (nr_args != 1) |
| return -EINVAL; |
| args = btf_params(dtor_func_proto); |
| t = btf_type_by_id(btf, args[0].type); |
| /* Allow any pointer type, as width on targets Linux supports |
| * will be same for all pointer types (i.e. sizeof(void *)) |
| */ |
| if (!t || !btf_type_is_ptr(t)) |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| /* This function must be invoked only from initcalls/module init functions */ |
| int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt, |
| struct module *owner) |
| { |
| struct btf_id_dtor_kfunc_tab *tab; |
| struct btf *btf; |
| u32 tab_cnt, i; |
| int ret; |
| |
| btf = btf_get_module_btf(owner); |
| if (!btf) |
| return check_btf_kconfigs(owner, "dtor kfuncs"); |
| if (IS_ERR(btf)) |
| return PTR_ERR(btf); |
| |
| if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { |
| pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); |
| ret = -E2BIG; |
| goto end; |
| } |
| |
| /* Ensure that the prototype of dtor kfuncs being registered is sane */ |
| ret = btf_check_dtor_kfuncs(btf, dtors, add_cnt); |
| if (ret < 0) |
| goto end; |
| |
| tab = btf->dtor_kfunc_tab; |
| /* Only one call allowed for modules */ |
| if (WARN_ON_ONCE(tab && btf_is_module(btf))) { |
| ret = -EINVAL; |
| goto end; |
| } |
| |
| tab_cnt = tab ? tab->cnt : 0; |
| if (tab_cnt > U32_MAX - add_cnt) { |
| ret = -EOVERFLOW; |
| goto end; |
| } |
| if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) { |
| pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT); |
| ret = -E2BIG; |
| goto end; |
| } |
| |
| tab = krealloc(btf->dtor_kfunc_tab, |
| offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!tab) { |
| ret = -ENOMEM; |
| goto end; |
| } |
| |
| if (!btf->dtor_kfunc_tab) |
| tab->cnt = 0; |
| btf->dtor_kfunc_tab = tab; |
| |
| memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0])); |
| |
| /* remap BTF ids based on BTF relocation (if any) */ |
| for (i = tab_cnt; i < tab_cnt + add_cnt; i++) { |
| tab->dtors[i].btf_id = btf_relocate_id(btf, tab->dtors[i].btf_id); |
| tab->dtors[i].kfunc_btf_id = btf_relocate_id(btf, tab->dtors[i].kfunc_btf_id); |
| } |
| |
| tab->cnt += add_cnt; |
| |
| sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL); |
| |
| end: |
| if (ret) |
| btf_free_dtor_kfunc_tab(btf); |
| btf_put(btf); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs); |
| |
| #define MAX_TYPES_ARE_COMPAT_DEPTH 2 |
| |
| /* Check local and target types for compatibility. This check is used for |
| * type-based CO-RE relocations and follow slightly different rules than |
| * field-based relocations. This function assumes that root types were already |
| * checked for name match. Beyond that initial root-level name check, names |
| * are completely ignored. Compatibility rules are as follows: |
| * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but |
| * kind should match for local and target types (i.e., STRUCT is not |
| * compatible with UNION); |
| * - for ENUMs/ENUM64s, the size is ignored; |
| * - for INT, size and signedness are ignored; |
| * - for ARRAY, dimensionality is ignored, element types are checked for |
| * compatibility recursively; |
| * - CONST/VOLATILE/RESTRICT modifiers are ignored; |
| * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible; |
| * - FUNC_PROTOs are compatible if they have compatible signature: same |
| * number of input args and compatible return and argument types. |
| * These rules are not set in stone and probably will be adjusted as we get |
| * more experience with using BPF CO-RE relocations. |
| */ |
| int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, |
| const struct btf *targ_btf, __u32 targ_id) |
| { |
| return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, |
| MAX_TYPES_ARE_COMPAT_DEPTH); |
| } |
| |
| #define MAX_TYPES_MATCH_DEPTH 2 |
| |
| int bpf_core_types_match(const struct btf *local_btf, u32 local_id, |
| const struct btf *targ_btf, u32 targ_id) |
| { |
| return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, |
| MAX_TYPES_MATCH_DEPTH); |
| } |
| |
| static bool bpf_core_is_flavor_sep(const char *s) |
| { |
| /* check X___Y name pattern, where X and Y are not underscores */ |
| return s[0] != '_' && /* X */ |
| s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */ |
| s[4] != '_'; /* Y */ |
| } |
| |
| size_t bpf_core_essential_name_len(const char *name) |
| { |
| size_t n = strlen(name); |
| int i; |
| |
| for (i = n - 5; i >= 0; i--) { |
| if (bpf_core_is_flavor_sep(name + i)) |
| return i + 1; |
| } |
| return n; |
| } |
| |
| static void bpf_free_cands(struct bpf_cand_cache *cands) |
| { |
| if (!cands->cnt) |
| /* empty candidate array was allocated on stack */ |
| return; |
| kfree(cands); |
| } |
| |
| static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands) |
| { |
| kfree(cands->name); |
| kfree(cands); |
| } |
| |
| #define VMLINUX_CAND_CACHE_SIZE 31 |
| static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE]; |
| |
| #define MODULE_CAND_CACHE_SIZE 31 |
| static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE]; |
| |
| static void __print_cand_cache(struct bpf_verifier_log *log, |
| struct bpf_cand_cache **cache, |
| int cache_size) |
| { |
| struct bpf_cand_cache *cc; |
| int i, j; |
| |
| for (i = 0; i < cache_size; i++) { |
| cc = cache[i]; |
| if (!cc) |
| continue; |
| bpf_log(log, "[%d]%s(", i, cc->name); |
| for (j = 0; j < cc->cnt; j++) { |
| bpf_log(log, "%d", cc->cands[j].id); |
| if (j < cc->cnt - 1) |
| bpf_log(log, " "); |
| } |
| bpf_log(log, "), "); |
| } |
| } |
| |
| static void print_cand_cache(struct bpf_verifier_log *log) |
| { |
| mutex_lock(&cand_cache_mutex); |
| bpf_log(log, "vmlinux_cand_cache:"); |
| __print_cand_cache(log, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
| bpf_log(log, "\nmodule_cand_cache:"); |
| __print_cand_cache(log, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| bpf_log(log, "\n"); |
| mutex_unlock(&cand_cache_mutex); |
| } |
| |
| static u32 hash_cands(struct bpf_cand_cache *cands) |
| { |
| return jhash(cands->name, cands->name_len, 0); |
| } |
| |
| static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands, |
| struct bpf_cand_cache **cache, |
| int cache_size) |
| { |
| struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size]; |
| |
| if (cc && cc->name_len == cands->name_len && |
| !strncmp(cc->name, cands->name, cands->name_len)) |
| return cc; |
| return NULL; |
| } |
| |
| static size_t sizeof_cands(int cnt) |
| { |
| return offsetof(struct bpf_cand_cache, cands[cnt]); |
| } |
| |
| static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands, |
| struct bpf_cand_cache **cache, |
| int cache_size) |
| { |
| struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands; |
| |
| if (*cc) { |
| bpf_free_cands_from_cache(*cc); |
| *cc = NULL; |
| } |
| new_cands = kmemdup(cands, sizeof_cands(cands->cnt), GFP_KERNEL); |
| if (!new_cands) { |
| bpf_free_cands(cands); |
| return ERR_PTR(-ENOMEM); |
| } |
| /* strdup the name, since it will stay in cache. |
| * the cands->name points to strings in prog's BTF and the prog can be unloaded. |
| */ |
| new_cands->name = kmemdup_nul(cands->name, cands->name_len, GFP_KERNEL); |
| bpf_free_cands(cands); |
| if (!new_cands->name) { |
| kfree(new_cands); |
| return ERR_PTR(-ENOMEM); |
| } |
| *cc = new_cands; |
| return new_cands; |
| } |
| |
| #ifdef CONFIG_DEBUG_INFO_BTF_MODULES |
| static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache, |
| int cache_size) |
| { |
| struct bpf_cand_cache *cc; |
| int i, j; |
| |
| for (i = 0; i < cache_size; i++) { |
| cc = cache[i]; |
| if (!cc) |
| continue; |
| if (!btf) { |
| /* when new module is loaded purge all of module_cand_cache, |
| * since new module might have candidates with the name |
| * that matches cached cands. |
| */ |
| bpf_free_cands_from_cache(cc); |
| cache[i] = NULL; |
| continue; |
| } |
| /* when module is unloaded purge cache entries |
| * that match module's btf |
| */ |
| for (j = 0; j < cc->cnt; j++) |
| if (cc->cands[j].btf == btf) { |
| bpf_free_cands_from_cache(cc); |
| cache[i] = NULL; |
| break; |
| } |
| } |
| |
| } |
| |
| static void purge_cand_cache(struct btf *btf) |
| { |
| mutex_lock(&cand_cache_mutex); |
| __purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| mutex_unlock(&cand_cache_mutex); |
| } |
| #endif |
| |
| static struct bpf_cand_cache * |
| bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf, |
| int targ_start_id) |
| { |
| struct bpf_cand_cache *new_cands; |
| const struct btf_type *t; |
| const char *targ_name; |
| size_t targ_essent_len; |
| int n, i; |
| |
| n = btf_nr_types(targ_btf); |
| for (i = targ_start_id; i < n; i++) { |
| t = btf_type_by_id(targ_btf, i); |
| if (btf_kind(t) != cands->kind) |
| continue; |
| |
| targ_name = btf_name_by_offset(targ_btf, t->name_off); |
| if (!targ_name) |
| continue; |
| |
| /* the resched point is before strncmp to make sure that search |
| * for non-existing name will have a chance to schedule(). |
| */ |
| cond_resched(); |
| |
| if (strncmp(cands->name, targ_name, cands->name_len) != 0) |
| continue; |
| |
| targ_essent_len = bpf_core_essential_name_len(targ_name); |
| if (targ_essent_len != cands->name_len) |
| continue; |
| |
| /* most of the time there is only one candidate for a given kind+name pair */ |
| new_cands = kmalloc(sizeof_cands(cands->cnt + 1), GFP_KERNEL); |
| if (!new_cands) { |
| bpf_free_cands(cands); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| memcpy(new_cands, cands, sizeof_cands(cands->cnt)); |
| bpf_free_cands(cands); |
| cands = new_cands; |
| cands->cands[cands->cnt].btf = targ_btf; |
| cands->cands[cands->cnt].id = i; |
| cands->cnt++; |
| } |
| return cands; |
| } |
| |
| static struct bpf_cand_cache * |
| bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id) |
| { |
| struct bpf_cand_cache *cands, *cc, local_cand = {}; |
| const struct btf *local_btf = ctx->btf; |
| const struct btf_type *local_type; |
| const struct btf *main_btf; |
| size_t local_essent_len; |
| struct btf *mod_btf; |
| const char *name; |
| int id; |
| |
| main_btf = bpf_get_btf_vmlinux(); |
| if (IS_ERR(main_btf)) |
| return ERR_CAST(main_btf); |
| if (!main_btf) |
| return ERR_PTR(-EINVAL); |
| |
| local_type = btf_type_by_id(local_btf, local_type_id); |
| if (!local_type) |
| return ERR_PTR(-EINVAL); |
| |
| name = btf_name_by_offset(local_btf, local_type->name_off); |
| if (str_is_empty(name)) |
| return ERR_PTR(-EINVAL); |
| local_essent_len = bpf_core_essential_name_len(name); |
| |
| cands = &local_cand; |
| cands->name = name; |
| cands->kind = btf_kind(local_type); |
| cands->name_len = local_essent_len; |
| |
| cc = check_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
| /* cands is a pointer to stack here */ |
| if (cc) { |
| if (cc->cnt) |
| return cc; |
| goto check_modules; |
| } |
| |
| /* Attempt to find target candidates in vmlinux BTF first */ |
| cands = bpf_core_add_cands(cands, main_btf, 1); |
| if (IS_ERR(cands)) |
| return ERR_CAST(cands); |
| |
| /* cands is a pointer to kmalloced memory here if cands->cnt > 0 */ |
| |
| /* populate cache even when cands->cnt == 0 */ |
| cc = populate_cand_cache(cands, vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE); |
| if (IS_ERR(cc)) |
| return ERR_CAST(cc); |
| |
| /* if vmlinux BTF has any candidate, don't go for module BTFs */ |
| if (cc->cnt) |
| return cc; |
| |
| check_modules: |
| /* cands is a pointer to stack here and cands->cnt == 0 */ |
| cc = check_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| if (cc) |
| /* if cache has it return it even if cc->cnt == 0 */ |
| return cc; |
| |
| /* If candidate is not found in vmlinux's BTF then search in module's BTFs */ |
| spin_lock_bh(&btf_idr_lock); |
| idr_for_each_entry(&btf_idr, mod_btf, id) { |
| if (!btf_is_module(mod_btf)) |
| continue; |
| /* linear search could be slow hence unlock/lock |
| * the IDR to avoiding holding it for too long |
| */ |
| btf_get(mod_btf); |
| spin_unlock_bh(&btf_idr_lock); |
| cands = bpf_core_add_cands(cands, mod_btf, btf_nr_types(main_btf)); |
| btf_put(mod_btf); |
| if (IS_ERR(cands)) |
| return ERR_CAST(cands); |
| spin_lock_bh(&btf_idr_lock); |
| } |
| spin_unlock_bh(&btf_idr_lock); |
| /* cands is a pointer to kmalloced memory here if cands->cnt > 0 |
| * or pointer to stack if cands->cnd == 0. |
| * Copy it into the cache even when cands->cnt == 0 and |
| * return the result. |
| */ |
| return populate_cand_cache(cands, module_cand_cache, MODULE_CAND_CACHE_SIZE); |
| } |
| |
| int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo, |
| int relo_idx, void *insn) |
| { |
| bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL; |
| struct bpf_core_cand_list cands = {}; |
| struct bpf_core_relo_res targ_res; |
| struct bpf_core_spec *specs; |
| const struct btf_type *type; |
| int err; |
| |
| /* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5" |
| * into arrays of btf_ids of struct fields and array indices. |
| */ |
| specs = kcalloc(3, sizeof(*specs), GFP_KERNEL); |
| if (!specs) |
| return -ENOMEM; |
| |
| type = btf_type_by_id(ctx->btf, relo->type_id); |
| if (!type) { |
| bpf_log(ctx->log, "relo #%u: bad type id %u\n", |
| relo_idx, relo->type_id); |
| return -EINVAL; |
| } |
| |
| if (need_cands) { |
| struct bpf_cand_cache *cc; |
| int i; |
| |
| mutex_lock(&cand_cache_mutex); |
| cc = bpf_core_find_cands(ctx, relo->type_id); |
| if (IS_ERR(cc)) { |
| bpf_log(ctx->log, "target candidate search failed for %d\n", |
| relo->type_id); |
| err = PTR_ERR(cc); |
| goto out; |
| } |
| if (cc->cnt) { |
| cands.cands = kcalloc(cc->cnt, sizeof(*cands.cands), GFP_KERNEL); |
| if (!cands.cands) { |
| err = -ENOMEM; |
| goto out; |
| } |
| } |
| for (i = 0; i < cc->cnt; i++) { |
| bpf_log(ctx->log, |
| "CO-RE relocating %s %s: found target candidate [%d]\n", |
| btf_kind_str[cc->kind], cc->name, cc->cands[i].id); |
| cands.cands[i].btf = cc->cands[i].btf; |
| cands.cands[i].id = cc->cands[i].id; |
| } |
| cands.len = cc->cnt; |
| /* cand_cache_mutex needs to span the cache lookup and |
| * copy of btf pointer into bpf_core_cand_list, |
| * since module can be unloaded while bpf_core_calc_relo_insn |
| * is working with module's btf. |
| */ |
| } |
| |
| err = bpf_core_calc_relo_insn((void *)ctx->log, relo, relo_idx, ctx->btf, &cands, specs, |
| &targ_res); |
| if (err) |
| goto out; |
| |
| err = bpf_core_patch_insn((void *)ctx->log, insn, relo->insn_off / 8, relo, relo_idx, |
| &targ_res); |
| |
| out: |
| kfree(specs); |
| if (need_cands) { |
| kfree(cands.cands); |
| mutex_unlock(&cand_cache_mutex); |
| if (ctx->log->level & BPF_LOG_LEVEL2) |
| print_cand_cache(ctx->log); |
| } |
| return err; |
| } |
| |
| bool btf_nested_type_is_trusted(struct bpf_verifier_log *log, |
| const struct bpf_reg_state *reg, |
| const char *field_name, u32 btf_id, const char *suffix) |
| { |
| struct btf *btf = reg->btf; |
| const struct btf_type *walk_type, *safe_type; |
| const char *tname; |
| char safe_tname[64]; |
| long ret, safe_id; |
| const struct btf_member *member; |
| u32 i; |
| |
| walk_type = btf_type_by_id(btf, reg->btf_id); |
| if (!walk_type) |
| return false; |
| |
| tname = btf_name_by_offset(btf, walk_type->name_off); |
| |
| ret = snprintf(safe_tname, sizeof(safe_tname), "%s%s", tname, suffix); |
| if (ret >= sizeof(safe_tname)) |
| return false; |
| |
| safe_id = btf_find_by_name_kind(btf, safe_tname, BTF_INFO_KIND(walk_type->info)); |
| if (safe_id < 0) |
| return false; |
| |
| safe_type = btf_type_by_id(btf, safe_id); |
| if (!safe_type) |
| return false; |
| |
| for_each_member(i, safe_type, member) { |
| const char *m_name = __btf_name_by_offset(btf, member->name_off); |
| const struct btf_type *mtype = btf_type_by_id(btf, member->type); |
| u32 id; |
| |
| if (!btf_type_is_ptr(mtype)) |
| continue; |
| |
| btf_type_skip_modifiers(btf, mtype->type, &id); |
| /* If we match on both type and name, the field is considered trusted. */ |
| if (btf_id == id && !strcmp(field_name, m_name)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log, |
| const struct btf *reg_btf, u32 reg_id, |
| const struct btf *arg_btf, u32 arg_id) |
| { |
| const char *reg_name, *arg_name, *search_needle; |
| const struct btf_type *reg_type, *arg_type; |
| int reg_len, arg_len, cmp_len; |
| size_t pattern_len = sizeof(NOCAST_ALIAS_SUFFIX) - sizeof(char); |
| |
| reg_type = btf_type_by_id(reg_btf, reg_id); |
| if (!reg_type) |
| return false; |
| |
| arg_type = btf_type_by_id(arg_btf, arg_id); |
| if (!arg_type) |
| return false; |
| |
| reg_name = btf_name_by_offset(reg_btf, reg_type->name_off); |
| arg_name = btf_name_by_offset(arg_btf, arg_type->name_off); |
| |
| reg_len = strlen(reg_name); |
| arg_len = strlen(arg_name); |
| |
| /* Exactly one of the two type names may be suffixed with ___init, so |
| * if the strings are the same size, they can't possibly be no-cast |
| * aliases of one another. If you have two of the same type names, e.g. |
| * they're both nf_conn___init, it would be improper to return true |
| * because they are _not_ no-cast aliases, they are the same type. |
| */ |
| if (reg_len == arg_len) |
| return false; |
| |
| /* Either of the two names must be the other name, suffixed with ___init. */ |
| if ((reg_len != arg_len + pattern_len) && |
| (arg_len != reg_len + pattern_len)) |
| return false; |
| |
| if (reg_len < arg_len) { |
| search_needle = strstr(arg_name, NOCAST_ALIAS_SUFFIX); |
| cmp_len = reg_len; |
| } else { |
| search_needle = strstr(reg_name, NOCAST_ALIAS_SUFFIX); |
| cmp_len = arg_len; |
| } |
| |
| if (!search_needle) |
| return false; |
| |
| /* ___init suffix must come at the end of the name */ |
| if (*(search_needle + pattern_len) != '\0') |
| return false; |
| |
| return !strncmp(reg_name, arg_name, cmp_len); |
| } |
| |
| #ifdef CONFIG_BPF_JIT |
| static int |
| btf_add_struct_ops(struct btf *btf, struct bpf_struct_ops *st_ops, |
| struct bpf_verifier_log *log) |
| { |
| struct btf_struct_ops_tab *tab, *new_tab; |
| int i, err; |
| |
| tab = btf->struct_ops_tab; |
| if (!tab) { |
| tab = kzalloc(offsetof(struct btf_struct_ops_tab, ops[4]), |
| GFP_KERNEL); |
| if (!tab) |
| return -ENOMEM; |
| tab->capacity = 4; |
| btf->struct_ops_tab = tab; |
| } |
| |
| for (i = 0; i < tab->cnt; i++) |
| if (tab->ops[i].st_ops == st_ops) |
| return -EEXIST; |
| |
| if (tab->cnt == tab->capacity) { |
| new_tab = krealloc(tab, |
| offsetof(struct btf_struct_ops_tab, |
| ops[tab->capacity * 2]), |
| GFP_KERNEL); |
| if (!new_tab) |
| return -ENOMEM; |
| tab = new_tab; |
| tab->capacity *= 2; |
| btf->struct_ops_tab = tab; |
| } |
| |
| tab->ops[btf->struct_ops_tab->cnt].st_ops = st_ops; |
| |
| err = bpf_struct_ops_desc_init(&tab->ops[btf->struct_ops_tab->cnt], btf, log); |
| if (err) |
| return err; |
| |
| btf->struct_ops_tab->cnt++; |
| |
| return 0; |
| } |
| |
| const struct bpf_struct_ops_desc * |
| bpf_struct_ops_find_value(struct btf *btf, u32 value_id) |
| { |
| const struct bpf_struct_ops_desc *st_ops_list; |
| unsigned int i; |
| u32 cnt; |
| |
| if (!value_id) |
| return NULL; |
| if (!btf->struct_ops_tab) |
| return NULL; |
| |
| cnt = btf->struct_ops_tab->cnt; |
| st_ops_list = btf->struct_ops_tab->ops; |
| for (i = 0; i < cnt; i++) { |
| if (st_ops_list[i].value_id == value_id) |
| return &st_ops_list[i]; |
| } |
| |
| return NULL; |
| } |
| |
| const struct bpf_struct_ops_desc * |
| bpf_struct_ops_find(struct btf *btf, u32 type_id) |
| { |
| const struct bpf_struct_ops_desc *st_ops_list; |
| unsigned int i; |
| u32 cnt; |
| |
| if (!type_id) |
| return NULL; |
| if (!btf->struct_ops_tab) |
| return NULL; |
| |
| cnt = btf->struct_ops_tab->cnt; |
| st_ops_list = btf->struct_ops_tab->ops; |
| for (i = 0; i < cnt; i++) { |
| if (st_ops_list[i].type_id == type_id) |
| return &st_ops_list[i]; |
| } |
| |
| return NULL; |
| } |
| |
| int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops) |
| { |
| struct bpf_verifier_log *log; |
| struct btf *btf; |
| int err = 0; |
| |
| btf = btf_get_module_btf(st_ops->owner); |
| if (!btf) |
| return check_btf_kconfigs(st_ops->owner, "struct_ops"); |
| if (IS_ERR(btf)) |
| return PTR_ERR(btf); |
| |
| log = kzalloc(sizeof(*log), GFP_KERNEL | __GFP_NOWARN); |
| if (!log) { |
| err = -ENOMEM; |
| goto errout; |
| } |
| |
| log->level = BPF_LOG_KERNEL; |
| |
| err = btf_add_struct_ops(btf, st_ops, log); |
| |
| errout: |
| kfree(log); |
| btf_put(btf); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(__register_bpf_struct_ops); |
| #endif |
| |
| bool btf_param_match_suffix(const struct btf *btf, |
| const struct btf_param *arg, |
| const char *suffix) |
| { |
| int suffix_len = strlen(suffix), len; |
| const char *param_name; |
| |
| /* In the future, this can be ported to use BTF tagging */ |
| param_name = btf_name_by_offset(btf, arg->name_off); |
| if (str_is_empty(param_name)) |
| return false; |
| len = strlen(param_name); |
| if (len <= suffix_len) |
| return false; |
| param_name += len - suffix_len; |
| return !strncmp(param_name, suffix, suffix_len); |
| } |