| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com |
| * Copyright (c) 2016 Facebook |
| */ |
| #include <linux/kernel.h> |
| #include <linux/types.h> |
| #include <linux/slab.h> |
| #include <linux/bpf.h> |
| #include <linux/bpf_verifier.h> |
| #include <linux/bpf_perf_event.h> |
| #include <linux/btf.h> |
| #include <linux/filter.h> |
| #include <linux/uaccess.h> |
| #include <linux/ctype.h> |
| #include <linux/kprobes.h> |
| #include <linux/spinlock.h> |
| #include <linux/syscalls.h> |
| #include <linux/error-injection.h> |
| #include <linux/btf_ids.h> |
| #include <linux/bpf_lsm.h> |
| #include <linux/fprobe.h> |
| #include <linux/bsearch.h> |
| #include <linux/sort.h> |
| #include <linux/key.h> |
| #include <linux/verification.h> |
| #include <linux/namei.h> |
| #include <linux/fileattr.h> |
| |
| #include <net/bpf_sk_storage.h> |
| |
| #include <uapi/linux/bpf.h> |
| #include <uapi/linux/btf.h> |
| |
| #include <asm/tlb.h> |
| |
| #include "trace_probe.h" |
| #include "trace.h" |
| |
| #define CREATE_TRACE_POINTS |
| #include "bpf_trace.h" |
| |
| #define bpf_event_rcu_dereference(p) \ |
| rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex)) |
| |
| #define MAX_UPROBE_MULTI_CNT (1U << 20) |
| #define MAX_KPROBE_MULTI_CNT (1U << 20) |
| |
| #ifdef CONFIG_MODULES |
| struct bpf_trace_module { |
| struct module *module; |
| struct list_head list; |
| }; |
| |
| static LIST_HEAD(bpf_trace_modules); |
| static DEFINE_MUTEX(bpf_module_mutex); |
| |
| static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) |
| { |
| struct bpf_raw_event_map *btp, *ret = NULL; |
| struct bpf_trace_module *btm; |
| unsigned int i; |
| |
| mutex_lock(&bpf_module_mutex); |
| list_for_each_entry(btm, &bpf_trace_modules, list) { |
| for (i = 0; i < btm->module->num_bpf_raw_events; ++i) { |
| btp = &btm->module->bpf_raw_events[i]; |
| if (!strcmp(btp->tp->name, name)) { |
| if (try_module_get(btm->module)) |
| ret = btp; |
| goto out; |
| } |
| } |
| } |
| out: |
| mutex_unlock(&bpf_module_mutex); |
| return ret; |
| } |
| #else |
| static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) |
| { |
| return NULL; |
| } |
| #endif /* CONFIG_MODULES */ |
| |
| u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
| u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); |
| |
| static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, |
| u64 flags, const struct btf **btf, |
| s32 *btf_id); |
| static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); |
| static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); |
| |
| static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx); |
| static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx); |
| |
| /** |
| * trace_call_bpf - invoke BPF program |
| * @call: tracepoint event |
| * @ctx: opaque context pointer |
| * |
| * kprobe handlers execute BPF programs via this helper. |
| * Can be used from static tracepoints in the future. |
| * |
| * Return: BPF programs always return an integer which is interpreted by |
| * kprobe handler as: |
| * 0 - return from kprobe (event is filtered out) |
| * 1 - store kprobe event into ring buffer |
| * Other values are reserved and currently alias to 1 |
| */ |
| unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) |
| { |
| unsigned int ret; |
| |
| cant_sleep(); |
| |
| if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { |
| /* |
| * since some bpf program is already running on this cpu, |
| * don't call into another bpf program (same or different) |
| * and don't send kprobe event into ring-buffer, |
| * so return zero here |
| */ |
| rcu_read_lock(); |
| bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); |
| rcu_read_unlock(); |
| ret = 0; |
| goto out; |
| } |
| |
| /* |
| * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock |
| * to all call sites, we did a bpf_prog_array_valid() there to check |
| * whether call->prog_array is empty or not, which is |
| * a heuristic to speed up execution. |
| * |
| * If bpf_prog_array_valid() fetched prog_array was |
| * non-NULL, we go into trace_call_bpf() and do the actual |
| * proper rcu_dereference() under RCU lock. |
| * If it turns out that prog_array is NULL then, we bail out. |
| * For the opposite, if the bpf_prog_array_valid() fetched pointer |
| * was NULL, you'll skip the prog_array with the risk of missing |
| * out of events when it was updated in between this and the |
| * rcu_dereference() which is accepted risk. |
| */ |
| rcu_read_lock(); |
| ret = bpf_prog_run_array(rcu_dereference(call->prog_array), |
| ctx, bpf_prog_run); |
| rcu_read_unlock(); |
| |
| out: |
| __this_cpu_dec(bpf_prog_active); |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc) |
| { |
| regs_set_return_value(regs, rc); |
| override_function_with_return(regs); |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_override_return_proto = { |
| .func = bpf_override_return, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| #endif |
| |
| static __always_inline int |
| bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr) |
| { |
| int ret; |
| |
| ret = copy_from_user_nofault(dst, unsafe_ptr, size); |
| if (unlikely(ret < 0)) |
| memset(dst, 0, size); |
| return ret; |
| } |
| |
| BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size, |
| const void __user *, unsafe_ptr) |
| { |
| return bpf_probe_read_user_common(dst, size, unsafe_ptr); |
| } |
| |
| const struct bpf_func_proto bpf_probe_read_user_proto = { |
| .func = bpf_probe_read_user, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| static __always_inline int |
| bpf_probe_read_user_str_common(void *dst, u32 size, |
| const void __user *unsafe_ptr) |
| { |
| int ret; |
| |
| /* |
| * NB: We rely on strncpy_from_user() not copying junk past the NUL |
| * terminator into `dst`. |
| * |
| * strncpy_from_user() does long-sized strides in the fast path. If the |
| * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`, |
| * then there could be junk after the NUL in `dst`. If user takes `dst` |
| * and keys a hash map with it, then semantically identical strings can |
| * occupy multiple entries in the map. |
| */ |
| ret = strncpy_from_user_nofault(dst, unsafe_ptr, size); |
| if (unlikely(ret < 0)) |
| memset(dst, 0, size); |
| return ret; |
| } |
| |
| BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size, |
| const void __user *, unsafe_ptr) |
| { |
| return bpf_probe_read_user_str_common(dst, size, unsafe_ptr); |
| } |
| |
| const struct bpf_func_proto bpf_probe_read_user_str_proto = { |
| .func = bpf_probe_read_user_str, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size, |
| const void *, unsafe_ptr) |
| { |
| return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); |
| } |
| |
| const struct bpf_func_proto bpf_probe_read_kernel_proto = { |
| .func = bpf_probe_read_kernel, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| static __always_inline int |
| bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr) |
| { |
| int ret; |
| |
| /* |
| * The strncpy_from_kernel_nofault() call will likely not fill the |
| * entire buffer, but that's okay in this circumstance as we're probing |
| * arbitrary memory anyway similar to bpf_probe_read_*() and might |
| * as well probe the stack. Thus, memory is explicitly cleared |
| * only in error case, so that improper users ignoring return |
| * code altogether don't copy garbage; otherwise length of string |
| * is returned that can be used for bpf_perf_event_output() et al. |
| */ |
| ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size); |
| if (unlikely(ret < 0)) |
| memset(dst, 0, size); |
| return ret; |
| } |
| |
| BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size, |
| const void *, unsafe_ptr) |
| { |
| return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); |
| } |
| |
| const struct bpf_func_proto bpf_probe_read_kernel_str_proto = { |
| .func = bpf_probe_read_kernel_str, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
| BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size, |
| const void *, unsafe_ptr) |
| { |
| if ((unsigned long)unsafe_ptr < TASK_SIZE) { |
| return bpf_probe_read_user_common(dst, size, |
| (__force void __user *)unsafe_ptr); |
| } |
| return bpf_probe_read_kernel_common(dst, size, unsafe_ptr); |
| } |
| |
| static const struct bpf_func_proto bpf_probe_read_compat_proto = { |
| .func = bpf_probe_read_compat, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size, |
| const void *, unsafe_ptr) |
| { |
| if ((unsigned long)unsafe_ptr < TASK_SIZE) { |
| return bpf_probe_read_user_str_common(dst, size, |
| (__force void __user *)unsafe_ptr); |
| } |
| return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr); |
| } |
| |
| static const struct bpf_func_proto bpf_probe_read_compat_str_proto = { |
| .func = bpf_probe_read_compat_str, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| #endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ |
| |
| BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src, |
| u32, size) |
| { |
| /* |
| * Ensure we're in user context which is safe for the helper to |
| * run. This helper has no business in a kthread. |
| * |
| * access_ok() should prevent writing to non-user memory, but in |
| * some situations (nommu, temporary switch, etc) access_ok() does |
| * not provide enough validation, hence the check on KERNEL_DS. |
| * |
| * nmi_uaccess_okay() ensures the probe is not run in an interim |
| * state, when the task or mm are switched. This is specifically |
| * required to prevent the use of temporary mm. |
| */ |
| |
| if (unlikely(in_interrupt() || |
| current->flags & (PF_KTHREAD | PF_EXITING))) |
| return -EPERM; |
| if (unlikely(!nmi_uaccess_okay())) |
| return -EPERM; |
| |
| return copy_to_user_nofault(unsafe_ptr, src, size); |
| } |
| |
| static const struct bpf_func_proto bpf_probe_write_user_proto = { |
| .func = bpf_probe_write_user, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_ANYTHING, |
| .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg3_type = ARG_CONST_SIZE, |
| }; |
| |
| static const struct bpf_func_proto *bpf_get_probe_write_proto(void) |
| { |
| if (!capable(CAP_SYS_ADMIN)) |
| return NULL; |
| |
| pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!", |
| current->comm, task_pid_nr(current)); |
| |
| return &bpf_probe_write_user_proto; |
| } |
| |
| #define MAX_TRACE_PRINTK_VARARGS 3 |
| #define BPF_TRACE_PRINTK_SIZE 1024 |
| |
| BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, |
| u64, arg2, u64, arg3) |
| { |
| u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; |
| struct bpf_bprintf_data data = { |
| .get_bin_args = true, |
| .get_buf = true, |
| }; |
| int ret; |
| |
| ret = bpf_bprintf_prepare(fmt, fmt_size, args, |
| MAX_TRACE_PRINTK_VARARGS, &data); |
| if (ret < 0) |
| return ret; |
| |
| ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); |
| |
| trace_bpf_trace_printk(data.buf); |
| |
| bpf_bprintf_cleanup(&data); |
| |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_trace_printk_proto = { |
| .func = bpf_trace_printk, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg2_type = ARG_CONST_SIZE, |
| }; |
| |
| static void __set_printk_clr_event(void) |
| { |
| /* |
| * This program might be calling bpf_trace_printk, |
| * so enable the associated bpf_trace/bpf_trace_printk event. |
| * Repeat this each time as it is possible a user has |
| * disabled bpf_trace_printk events. By loading a program |
| * calling bpf_trace_printk() however the user has expressed |
| * the intent to see such events. |
| */ |
| if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) |
| pr_warn_ratelimited("could not enable bpf_trace_printk events"); |
| } |
| |
| const struct bpf_func_proto *bpf_get_trace_printk_proto(void) |
| { |
| __set_printk_clr_event(); |
| return &bpf_trace_printk_proto; |
| } |
| |
| BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, |
| u32, data_len) |
| { |
| struct bpf_bprintf_data data = { |
| .get_bin_args = true, |
| .get_buf = true, |
| }; |
| int ret, num_args; |
| |
| if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || |
| (data_len && !args)) |
| return -EINVAL; |
| num_args = data_len / 8; |
| |
| ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); |
| if (ret < 0) |
| return ret; |
| |
| ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); |
| |
| trace_bpf_trace_printk(data.buf); |
| |
| bpf_bprintf_cleanup(&data); |
| |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_trace_vprintk_proto = { |
| .func = bpf_trace_vprintk, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg2_type = ARG_CONST_SIZE, |
| .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, |
| .arg4_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) |
| { |
| __set_printk_clr_event(); |
| return &bpf_trace_vprintk_proto; |
| } |
| |
| BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, |
| const void *, args, u32, data_len) |
| { |
| struct bpf_bprintf_data data = { |
| .get_bin_args = true, |
| }; |
| int err, num_args; |
| |
| if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || |
| (data_len && !args)) |
| return -EINVAL; |
| num_args = data_len / 8; |
| |
| err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); |
| if (err < 0) |
| return err; |
| |
| seq_bprintf(m, fmt, data.bin_args); |
| |
| bpf_bprintf_cleanup(&data); |
| |
| return seq_has_overflowed(m) ? -EOVERFLOW : 0; |
| } |
| |
| BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file) |
| |
| static const struct bpf_func_proto bpf_seq_printf_proto = { |
| .func = bpf_seq_printf, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_BTF_ID, |
| .arg1_btf_id = &btf_seq_file_ids[0], |
| .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg3_type = ARG_CONST_SIZE, |
| .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len) |
| { |
| return seq_write(m, data, len) ? -EOVERFLOW : 0; |
| } |
| |
| static const struct bpf_func_proto bpf_seq_write_proto = { |
| .func = bpf_seq_write, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_BTF_ID, |
| .arg1_btf_id = &btf_seq_file_ids[0], |
| .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, |
| u32, btf_ptr_size, u64, flags) |
| { |
| const struct btf *btf; |
| s32 btf_id; |
| int ret; |
| |
| ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); |
| if (ret) |
| return ret; |
| |
| return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); |
| } |
| |
| static const struct bpf_func_proto bpf_seq_printf_btf_proto = { |
| .func = bpf_seq_printf_btf, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_BTF_ID, |
| .arg1_btf_id = &btf_seq_file_ids[0], |
| .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static __always_inline int |
| get_map_perf_counter(struct bpf_map *map, u64 flags, |
| u64 *value, u64 *enabled, u64 *running) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| unsigned int cpu = smp_processor_id(); |
| u64 index = flags & BPF_F_INDEX_MASK; |
| struct bpf_event_entry *ee; |
| |
| if (unlikely(flags & ~(BPF_F_INDEX_MASK))) |
| return -EINVAL; |
| if (index == BPF_F_CURRENT_CPU) |
| index = cpu; |
| if (unlikely(index >= array->map.max_entries)) |
| return -E2BIG; |
| |
| ee = READ_ONCE(array->ptrs[index]); |
| if (!ee) |
| return -ENOENT; |
| |
| return perf_event_read_local(ee->event, value, enabled, running); |
| } |
| |
| BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags) |
| { |
| u64 value = 0; |
| int err; |
| |
| err = get_map_perf_counter(map, flags, &value, NULL, NULL); |
| /* |
| * this api is ugly since we miss [-22..-2] range of valid |
| * counter values, but that's uapi |
| */ |
| if (err) |
| return err; |
| return value; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_read_proto = { |
| .func = bpf_perf_event_read, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags, |
| struct bpf_perf_event_value *, buf, u32, size) |
| { |
| int err = -EINVAL; |
| |
| if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| goto clear; |
| err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled, |
| &buf->running); |
| if (unlikely(err)) |
| goto clear; |
| return 0; |
| clear: |
| memset(buf, 0, size); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_read_value_proto = { |
| .func = bpf_perf_event_read_value, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg4_type = ARG_CONST_SIZE, |
| }; |
| |
| static __always_inline u64 |
| __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map, |
| u64 flags, struct perf_sample_data *sd) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| unsigned int cpu = smp_processor_id(); |
| u64 index = flags & BPF_F_INDEX_MASK; |
| struct bpf_event_entry *ee; |
| struct perf_event *event; |
| |
| if (index == BPF_F_CURRENT_CPU) |
| index = cpu; |
| if (unlikely(index >= array->map.max_entries)) |
| return -E2BIG; |
| |
| ee = READ_ONCE(array->ptrs[index]); |
| if (!ee) |
| return -ENOENT; |
| |
| event = ee->event; |
| if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE || |
| event->attr.config != PERF_COUNT_SW_BPF_OUTPUT)) |
| return -EINVAL; |
| |
| if (unlikely(event->oncpu != cpu)) |
| return -EOPNOTSUPP; |
| |
| return perf_event_output(event, sd, regs); |
| } |
| |
| /* |
| * Support executing tracepoints in normal, irq, and nmi context that each call |
| * bpf_perf_event_output |
| */ |
| struct bpf_trace_sample_data { |
| struct perf_sample_data sds[3]; |
| }; |
| |
| static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds); |
| static DEFINE_PER_CPU(int, bpf_trace_nest_level); |
| BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, |
| u64, flags, void *, data, u64, size) |
| { |
| struct bpf_trace_sample_data *sds; |
| struct perf_raw_record raw = { |
| .frag = { |
| .size = size, |
| .data = data, |
| }, |
| }; |
| struct perf_sample_data *sd; |
| int nest_level, err; |
| |
| preempt_disable(); |
| sds = this_cpu_ptr(&bpf_trace_sds); |
| nest_level = this_cpu_inc_return(bpf_trace_nest_level); |
| |
| if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) { |
| err = -EBUSY; |
| goto out; |
| } |
| |
| sd = &sds->sds[nest_level - 1]; |
| |
| if (unlikely(flags & ~(BPF_F_INDEX_MASK))) { |
| err = -EINVAL; |
| goto out; |
| } |
| |
| perf_sample_data_init(sd, 0, 0); |
| perf_sample_save_raw_data(sd, &raw); |
| |
| err = __bpf_perf_event_output(regs, map, flags, sd); |
| out: |
| this_cpu_dec(bpf_trace_nest_level); |
| preempt_enable(); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_output_proto = { |
| .func = bpf_perf_event_output, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| static DEFINE_PER_CPU(int, bpf_event_output_nest_level); |
| struct bpf_nested_pt_regs { |
| struct pt_regs regs[3]; |
| }; |
| static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs); |
| static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds); |
| |
| u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, |
| void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) |
| { |
| struct perf_raw_frag frag = { |
| .copy = ctx_copy, |
| .size = ctx_size, |
| .data = ctx, |
| }; |
| struct perf_raw_record raw = { |
| .frag = { |
| { |
| .next = ctx_size ? &frag : NULL, |
| }, |
| .size = meta_size, |
| .data = meta, |
| }, |
| }; |
| struct perf_sample_data *sd; |
| struct pt_regs *regs; |
| int nest_level; |
| u64 ret; |
| |
| preempt_disable(); |
| nest_level = this_cpu_inc_return(bpf_event_output_nest_level); |
| |
| if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) { |
| ret = -EBUSY; |
| goto out; |
| } |
| sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]); |
| regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]); |
| |
| perf_fetch_caller_regs(regs); |
| perf_sample_data_init(sd, 0, 0); |
| perf_sample_save_raw_data(sd, &raw); |
| |
| ret = __bpf_perf_event_output(regs, map, flags, sd); |
| out: |
| this_cpu_dec(bpf_event_output_nest_level); |
| preempt_enable(); |
| return ret; |
| } |
| |
| BPF_CALL_0(bpf_get_current_task) |
| { |
| return (long) current; |
| } |
| |
| const struct bpf_func_proto bpf_get_current_task_proto = { |
| .func = bpf_get_current_task, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_0(bpf_get_current_task_btf) |
| { |
| return (unsigned long) current; |
| } |
| |
| const struct bpf_func_proto bpf_get_current_task_btf_proto = { |
| .func = bpf_get_current_task_btf, |
| .gpl_only = true, |
| .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, |
| .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], |
| }; |
| |
| BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task) |
| { |
| return (unsigned long) task_pt_regs(task); |
| } |
| |
| BTF_ID_LIST(bpf_task_pt_regs_ids) |
| BTF_ID(struct, pt_regs) |
| |
| const struct bpf_func_proto bpf_task_pt_regs_proto = { |
| .func = bpf_task_pt_regs, |
| .gpl_only = true, |
| .arg1_type = ARG_PTR_TO_BTF_ID, |
| .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], |
| .ret_type = RET_PTR_TO_BTF_ID, |
| .ret_btf_id = &bpf_task_pt_regs_ids[0], |
| }; |
| |
| BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) |
| { |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| struct cgroup *cgrp; |
| |
| if (unlikely(idx >= array->map.max_entries)) |
| return -E2BIG; |
| |
| cgrp = READ_ONCE(array->ptrs[idx]); |
| if (unlikely(!cgrp)) |
| return -EAGAIN; |
| |
| return task_under_cgroup_hierarchy(current, cgrp); |
| } |
| |
| static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { |
| .func = bpf_current_task_under_cgroup, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| |
| struct send_signal_irq_work { |
| struct irq_work irq_work; |
| struct task_struct *task; |
| u32 sig; |
| enum pid_type type; |
| }; |
| |
| static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work); |
| |
| static void do_bpf_send_signal(struct irq_work *entry) |
| { |
| struct send_signal_irq_work *work; |
| |
| work = container_of(entry, struct send_signal_irq_work, irq_work); |
| group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); |
| put_task_struct(work->task); |
| } |
| |
| static int bpf_send_signal_common(u32 sig, enum pid_type type) |
| { |
| struct send_signal_irq_work *work = NULL; |
| |
| /* Similar to bpf_probe_write_user, task needs to be |
| * in a sound condition and kernel memory access be |
| * permitted in order to send signal to the current |
| * task. |
| */ |
| if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING))) |
| return -EPERM; |
| if (unlikely(!nmi_uaccess_okay())) |
| return -EPERM; |
| /* Task should not be pid=1 to avoid kernel panic. */ |
| if (unlikely(is_global_init(current))) |
| return -EPERM; |
| |
| if (irqs_disabled()) { |
| /* Do an early check on signal validity. Otherwise, |
| * the error is lost in deferred irq_work. |
| */ |
| if (unlikely(!valid_signal(sig))) |
| return -EINVAL; |
| |
| work = this_cpu_ptr(&send_signal_work); |
| if (irq_work_is_busy(&work->irq_work)) |
| return -EBUSY; |
| |
| /* Add the current task, which is the target of sending signal, |
| * to the irq_work. The current task may change when queued |
| * irq works get executed. |
| */ |
| work->task = get_task_struct(current); |
| work->sig = sig; |
| work->type = type; |
| irq_work_queue(&work->irq_work); |
| return 0; |
| } |
| |
| return group_send_sig_info(sig, SEND_SIG_PRIV, current, type); |
| } |
| |
| BPF_CALL_1(bpf_send_signal, u32, sig) |
| { |
| return bpf_send_signal_common(sig, PIDTYPE_TGID); |
| } |
| |
| static const struct bpf_func_proto bpf_send_signal_proto = { |
| .func = bpf_send_signal, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_1(bpf_send_signal_thread, u32, sig) |
| { |
| return bpf_send_signal_common(sig, PIDTYPE_PID); |
| } |
| |
| static const struct bpf_func_proto bpf_send_signal_thread_proto = { |
| .func = bpf_send_signal_thread, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz) |
| { |
| struct path copy; |
| long len; |
| char *p; |
| |
| if (!sz) |
| return 0; |
| |
| /* |
| * The path pointer is verified as trusted and safe to use, |
| * but let's double check it's valid anyway to workaround |
| * potentially broken verifier. |
| */ |
| len = copy_from_kernel_nofault(©, path, sizeof(*path)); |
| if (len < 0) |
| return len; |
| |
| p = d_path(©, buf, sz); |
| if (IS_ERR(p)) { |
| len = PTR_ERR(p); |
| } else { |
| len = buf + sz - p; |
| memmove(buf, p, len); |
| } |
| |
| return len; |
| } |
| |
| BTF_SET_START(btf_allowlist_d_path) |
| #ifdef CONFIG_SECURITY |
| BTF_ID(func, security_file_permission) |
| BTF_ID(func, security_inode_getattr) |
| BTF_ID(func, security_file_open) |
| #endif |
| #ifdef CONFIG_SECURITY_PATH |
| BTF_ID(func, security_path_truncate) |
| #endif |
| BTF_ID(func, vfs_truncate) |
| BTF_ID(func, vfs_fallocate) |
| BTF_ID(func, dentry_open) |
| BTF_ID(func, vfs_getattr) |
| BTF_ID(func, filp_close) |
| BTF_SET_END(btf_allowlist_d_path) |
| |
| static bool bpf_d_path_allowed(const struct bpf_prog *prog) |
| { |
| if (prog->type == BPF_PROG_TYPE_TRACING && |
| prog->expected_attach_type == BPF_TRACE_ITER) |
| return true; |
| |
| if (prog->type == BPF_PROG_TYPE_LSM) |
| return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id); |
| |
| return btf_id_set_contains(&btf_allowlist_d_path, |
| prog->aux->attach_btf_id); |
| } |
| |
| BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path) |
| |
| static const struct bpf_func_proto bpf_d_path_proto = { |
| .func = bpf_d_path, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_BTF_ID, |
| .arg1_btf_id = &bpf_d_path_btf_ids[0], |
| .arg2_type = ARG_PTR_TO_MEM, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .allowed = bpf_d_path_allowed, |
| }; |
| |
| #define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \ |
| BTF_F_PTR_RAW | BTF_F_ZERO) |
| |
| static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, |
| u64 flags, const struct btf **btf, |
| s32 *btf_id) |
| { |
| const struct btf_type *t; |
| |
| if (unlikely(flags & ~(BTF_F_ALL))) |
| return -EINVAL; |
| |
| if (btf_ptr_size != sizeof(struct btf_ptr)) |
| return -EINVAL; |
| |
| *btf = bpf_get_btf_vmlinux(); |
| |
| if (IS_ERR_OR_NULL(*btf)) |
| return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL; |
| |
| if (ptr->type_id > 0) |
| *btf_id = ptr->type_id; |
| else |
| return -EINVAL; |
| |
| if (*btf_id > 0) |
| t = btf_type_by_id(*btf, *btf_id); |
| if (*btf_id <= 0 || !t) |
| return -ENOENT; |
| |
| return 0; |
| } |
| |
| BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr, |
| u32, btf_ptr_size, u64, flags) |
| { |
| const struct btf *btf; |
| s32 btf_id; |
| int ret; |
| |
| ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); |
| if (ret) |
| return ret; |
| |
| return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size, |
| flags); |
| } |
| |
| const struct bpf_func_proto bpf_snprintf_btf_proto = { |
| .func = bpf_snprintf_btf, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_MEM, |
| .arg2_type = ARG_CONST_SIZE, |
| .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg4_type = ARG_CONST_SIZE, |
| .arg5_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) |
| { |
| /* This helper call is inlined by verifier. */ |
| return ((u64 *)ctx)[-2]; |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { |
| .func = bpf_get_func_ip_tracing, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| #ifdef CONFIG_X86_KERNEL_IBT |
| static unsigned long get_entry_ip(unsigned long fentry_ip) |
| { |
| u32 instr; |
| |
| /* Being extra safe in here in case entry ip is on the page-edge. */ |
| if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) |
| return fentry_ip; |
| if (is_endbr(instr)) |
| fentry_ip -= ENDBR_INSN_SIZE; |
| return fentry_ip; |
| } |
| #else |
| #define get_entry_ip(fentry_ip) fentry_ip |
| #endif |
| |
| BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) |
| { |
| struct bpf_trace_run_ctx *run_ctx __maybe_unused; |
| struct kprobe *kp; |
| |
| #ifdef CONFIG_UPROBES |
| run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); |
| if (run_ctx->is_uprobe) |
| return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr; |
| #endif |
| |
| kp = kprobe_running(); |
| |
| if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) |
| return 0; |
| |
| return get_entry_ip((uintptr_t)kp->addr); |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { |
| .func = bpf_get_func_ip_kprobe, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) |
| { |
| return bpf_kprobe_multi_entry_ip(current->bpf_ctx); |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { |
| .func = bpf_get_func_ip_kprobe_multi, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) |
| { |
| return bpf_kprobe_multi_cookie(current->bpf_ctx); |
| } |
| |
| static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { |
| .func = bpf_get_attach_cookie_kprobe_multi, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs) |
| { |
| return bpf_uprobe_multi_entry_ip(current->bpf_ctx); |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = { |
| .func = bpf_get_func_ip_uprobe_multi, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs) |
| { |
| return bpf_uprobe_multi_cookie(current->bpf_ctx); |
| } |
| |
| static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = { |
| .func = bpf_get_attach_cookie_uprobe_multi, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx) |
| { |
| struct bpf_trace_run_ctx *run_ctx; |
| |
| run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); |
| return run_ctx->bpf_cookie; |
| } |
| |
| static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = { |
| .func = bpf_get_attach_cookie_trace, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx) |
| { |
| return ctx->event->bpf_cookie; |
| } |
| |
| static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = { |
| .func = bpf_get_attach_cookie_pe, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx) |
| { |
| struct bpf_trace_run_ctx *run_ctx; |
| |
| run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx); |
| return run_ctx->bpf_cookie; |
| } |
| |
| static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = { |
| .func = bpf_get_attach_cookie_tracing, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags) |
| { |
| #ifndef CONFIG_X86 |
| return -ENOENT; |
| #else |
| static const u32 br_entry_size = sizeof(struct perf_branch_entry); |
| u32 entry_cnt = size / br_entry_size; |
| |
| entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt); |
| |
| if (unlikely(flags)) |
| return -EINVAL; |
| |
| if (!entry_cnt) |
| return -ENOENT; |
| |
| return entry_cnt * br_entry_size; |
| #endif |
| } |
| |
| static const struct bpf_func_proto bpf_get_branch_snapshot_proto = { |
| .func = bpf_get_branch_snapshot, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value) |
| { |
| /* This helper call is inlined by verifier. */ |
| u64 nr_args = ((u64 *)ctx)[-1]; |
| |
| if ((u64) n >= nr_args) |
| return -EINVAL; |
| *value = ((u64 *)ctx)[n]; |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_arg_proto = { |
| .func = get_func_arg, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_ANYTHING, |
| .arg3_type = ARG_PTR_TO_LONG, |
| }; |
| |
| BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value) |
| { |
| /* This helper call is inlined by verifier. */ |
| u64 nr_args = ((u64 *)ctx)[-1]; |
| |
| *value = ((u64 *)ctx)[nr_args]; |
| return 0; |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_ret_proto = { |
| .func = get_func_ret, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_LONG, |
| }; |
| |
| BPF_CALL_1(get_func_arg_cnt, void *, ctx) |
| { |
| /* This helper call is inlined by verifier. */ |
| return ((u64 *)ctx)[-1]; |
| } |
| |
| static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { |
| .func = get_func_arg_cnt, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| }; |
| |
| #ifdef CONFIG_KEYS |
| __bpf_kfunc_start_defs(); |
| |
| /** |
| * bpf_lookup_user_key - lookup a key by its serial |
| * @serial: key handle serial number |
| * @flags: lookup-specific flags |
| * |
| * Search a key with a given *serial* and the provided *flags*. |
| * If found, increment the reference count of the key by one, and |
| * return it in the bpf_key structure. |
| * |
| * The bpf_key structure must be passed to bpf_key_put() when done |
| * with it, so that the key reference count is decremented and the |
| * bpf_key structure is freed. |
| * |
| * Permission checks are deferred to the time the key is used by |
| * one of the available key-specific kfuncs. |
| * |
| * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested |
| * special keyring (e.g. session keyring), if it doesn't yet exist. |
| * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting |
| * for the key construction, and to retrieve uninstantiated keys (keys |
| * without data attached to them). |
| * |
| * Return: a bpf_key pointer with a valid key pointer if the key is found, a |
| * NULL pointer otherwise. |
| */ |
| __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) |
| { |
| key_ref_t key_ref; |
| struct bpf_key *bkey; |
| |
| if (flags & ~KEY_LOOKUP_ALL) |
| return NULL; |
| |
| /* |
| * Permission check is deferred until the key is used, as the |
| * intent of the caller is unknown here. |
| */ |
| key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); |
| if (IS_ERR(key_ref)) |
| return NULL; |
| |
| bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); |
| if (!bkey) { |
| key_put(key_ref_to_ptr(key_ref)); |
| return NULL; |
| } |
| |
| bkey->key = key_ref_to_ptr(key_ref); |
| bkey->has_ref = true; |
| |
| return bkey; |
| } |
| |
| /** |
| * bpf_lookup_system_key - lookup a key by a system-defined ID |
| * @id: key ID |
| * |
| * Obtain a bpf_key structure with a key pointer set to the passed key ID. |
| * The key pointer is marked as invalid, to prevent bpf_key_put() from |
| * attempting to decrement the key reference count on that pointer. The key |
| * pointer set in such way is currently understood only by |
| * verify_pkcs7_signature(). |
| * |
| * Set *id* to one of the values defined in include/linux/verification.h: |
| * 0 for the primary keyring (immutable keyring of system keys); |
| * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring |
| * (where keys can be added only if they are vouched for by existing keys |
| * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform |
| * keyring (primarily used by the integrity subsystem to verify a kexec'ed |
| * kerned image and, possibly, the initramfs signature). |
| * |
| * Return: a bpf_key pointer with an invalid key pointer set from the |
| * pre-determined ID on success, a NULL pointer otherwise |
| */ |
| __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) |
| { |
| struct bpf_key *bkey; |
| |
| if (system_keyring_id_check(id) < 0) |
| return NULL; |
| |
| bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); |
| if (!bkey) |
| return NULL; |
| |
| bkey->key = (struct key *)(unsigned long)id; |
| bkey->has_ref = false; |
| |
| return bkey; |
| } |
| |
| /** |
| * bpf_key_put - decrement key reference count if key is valid and free bpf_key |
| * @bkey: bpf_key structure |
| * |
| * Decrement the reference count of the key inside *bkey*, if the pointer |
| * is valid, and free *bkey*. |
| */ |
| __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) |
| { |
| if (bkey->has_ref) |
| key_put(bkey->key); |
| |
| kfree(bkey); |
| } |
| |
| #ifdef CONFIG_SYSTEM_DATA_VERIFICATION |
| /** |
| * bpf_verify_pkcs7_signature - verify a PKCS#7 signature |
| * @data_ptr: data to verify |
| * @sig_ptr: signature of the data |
| * @trusted_keyring: keyring with keys trusted for signature verification |
| * |
| * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* |
| * with keys in a keyring referenced by *trusted_keyring*. |
| * |
| * Return: 0 on success, a negative value on error. |
| */ |
| __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, |
| struct bpf_dynptr_kern *sig_ptr, |
| struct bpf_key *trusted_keyring) |
| { |
| const void *data, *sig; |
| u32 data_len, sig_len; |
| int ret; |
| |
| if (trusted_keyring->has_ref) { |
| /* |
| * Do the permission check deferred in bpf_lookup_user_key(). |
| * See bpf_lookup_user_key() for more details. |
| * |
| * A call to key_task_permission() here would be redundant, as |
| * it is already done by keyring_search() called by |
| * find_asymmetric_key(). |
| */ |
| ret = key_validate(trusted_keyring->key); |
| if (ret < 0) |
| return ret; |
| } |
| |
| data_len = __bpf_dynptr_size(data_ptr); |
| data = __bpf_dynptr_data(data_ptr, data_len); |
| sig_len = __bpf_dynptr_size(sig_ptr); |
| sig = __bpf_dynptr_data(sig_ptr, sig_len); |
| |
| return verify_pkcs7_signature(data, data_len, sig, sig_len, |
| trusted_keyring->key, |
| VERIFYING_UNSPECIFIED_SIGNATURE, NULL, |
| NULL); |
| } |
| #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ |
| |
| __bpf_kfunc_end_defs(); |
| |
| BTF_KFUNCS_START(key_sig_kfunc_set) |
| BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) |
| BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) |
| BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) |
| #ifdef CONFIG_SYSTEM_DATA_VERIFICATION |
| BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) |
| #endif |
| BTF_KFUNCS_END(key_sig_kfunc_set) |
| |
| static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { |
| .owner = THIS_MODULE, |
| .set = &key_sig_kfunc_set, |
| }; |
| |
| static int __init bpf_key_sig_kfuncs_init(void) |
| { |
| return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, |
| &bpf_key_sig_kfunc_set); |
| } |
| |
| late_initcall(bpf_key_sig_kfuncs_init); |
| #endif /* CONFIG_KEYS */ |
| |
| /* filesystem kfuncs */ |
| __bpf_kfunc_start_defs(); |
| |
| /** |
| * bpf_get_file_xattr - get xattr of a file |
| * @file: file to get xattr from |
| * @name__str: name of the xattr |
| * @value_ptr: output buffer of the xattr value |
| * |
| * Get xattr *name__str* of *file* and store the output in *value_ptr*. |
| * |
| * For security reasons, only *name__str* with prefix "user." is allowed. |
| * |
| * Return: 0 on success, a negative value on error. |
| */ |
| __bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str, |
| struct bpf_dynptr_kern *value_ptr) |
| { |
| struct dentry *dentry; |
| u32 value_len; |
| void *value; |
| int ret; |
| |
| if (strncmp(name__str, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) |
| return -EPERM; |
| |
| value_len = __bpf_dynptr_size(value_ptr); |
| value = __bpf_dynptr_data_rw(value_ptr, value_len); |
| if (!value) |
| return -EINVAL; |
| |
| dentry = file_dentry(file); |
| ret = inode_permission(&nop_mnt_idmap, dentry->d_inode, MAY_READ); |
| if (ret) |
| return ret; |
| return __vfs_getxattr(dentry, dentry->d_inode, name__str, value, value_len); |
| } |
| |
| __bpf_kfunc_end_defs(); |
| |
| BTF_KFUNCS_START(fs_kfunc_set_ids) |
| BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS) |
| BTF_KFUNCS_END(fs_kfunc_set_ids) |
| |
| static int bpf_get_file_xattr_filter(const struct bpf_prog *prog, u32 kfunc_id) |
| { |
| if (!btf_id_set8_contains(&fs_kfunc_set_ids, kfunc_id)) |
| return 0; |
| |
| /* Only allow to attach from LSM hooks, to avoid recursion */ |
| return prog->type != BPF_PROG_TYPE_LSM ? -EACCES : 0; |
| } |
| |
| static const struct btf_kfunc_id_set bpf_fs_kfunc_set = { |
| .owner = THIS_MODULE, |
| .set = &fs_kfunc_set_ids, |
| .filter = bpf_get_file_xattr_filter, |
| }; |
| |
| static int __init bpf_fs_kfuncs_init(void) |
| { |
| return register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM, &bpf_fs_kfunc_set); |
| } |
| |
| late_initcall(bpf_fs_kfuncs_init); |
| |
| static const struct bpf_func_proto * |
| bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_map_lookup_elem: |
| return &bpf_map_lookup_elem_proto; |
| case BPF_FUNC_map_update_elem: |
| return &bpf_map_update_elem_proto; |
| case BPF_FUNC_map_delete_elem: |
| return &bpf_map_delete_elem_proto; |
| case BPF_FUNC_map_push_elem: |
| return &bpf_map_push_elem_proto; |
| case BPF_FUNC_map_pop_elem: |
| return &bpf_map_pop_elem_proto; |
| case BPF_FUNC_map_peek_elem: |
| return &bpf_map_peek_elem_proto; |
| case BPF_FUNC_map_lookup_percpu_elem: |
| return &bpf_map_lookup_percpu_elem_proto; |
| case BPF_FUNC_ktime_get_ns: |
| return &bpf_ktime_get_ns_proto; |
| case BPF_FUNC_ktime_get_boot_ns: |
| return &bpf_ktime_get_boot_ns_proto; |
| case BPF_FUNC_tail_call: |
| return &bpf_tail_call_proto; |
| case BPF_FUNC_get_current_pid_tgid: |
| return &bpf_get_current_pid_tgid_proto; |
| case BPF_FUNC_get_current_task: |
| return &bpf_get_current_task_proto; |
| case BPF_FUNC_get_current_task_btf: |
| return &bpf_get_current_task_btf_proto; |
| case BPF_FUNC_task_pt_regs: |
| return &bpf_task_pt_regs_proto; |
| case BPF_FUNC_get_current_uid_gid: |
| return &bpf_get_current_uid_gid_proto; |
| case BPF_FUNC_get_current_comm: |
| return &bpf_get_current_comm_proto; |
| case BPF_FUNC_trace_printk: |
| return bpf_get_trace_printk_proto(); |
| case BPF_FUNC_get_smp_processor_id: |
| return &bpf_get_smp_processor_id_proto; |
| case BPF_FUNC_get_numa_node_id: |
| return &bpf_get_numa_node_id_proto; |
| case BPF_FUNC_perf_event_read: |
| return &bpf_perf_event_read_proto; |
| case BPF_FUNC_current_task_under_cgroup: |
| return &bpf_current_task_under_cgroup_proto; |
| case BPF_FUNC_get_prandom_u32: |
| return &bpf_get_prandom_u32_proto; |
| case BPF_FUNC_probe_write_user: |
| return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? |
| NULL : bpf_get_probe_write_proto(); |
| case BPF_FUNC_probe_read_user: |
| return &bpf_probe_read_user_proto; |
| case BPF_FUNC_probe_read_kernel: |
| return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? |
| NULL : &bpf_probe_read_kernel_proto; |
| case BPF_FUNC_probe_read_user_str: |
| return &bpf_probe_read_user_str_proto; |
| case BPF_FUNC_probe_read_kernel_str: |
| return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? |
| NULL : &bpf_probe_read_kernel_str_proto; |
| #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
| case BPF_FUNC_probe_read: |
| return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? |
| NULL : &bpf_probe_read_compat_proto; |
| case BPF_FUNC_probe_read_str: |
| return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? |
| NULL : &bpf_probe_read_compat_str_proto; |
| #endif |
| #ifdef CONFIG_CGROUPS |
| case BPF_FUNC_cgrp_storage_get: |
| return &bpf_cgrp_storage_get_proto; |
| case BPF_FUNC_cgrp_storage_delete: |
| return &bpf_cgrp_storage_delete_proto; |
| #endif |
| case BPF_FUNC_send_signal: |
| return &bpf_send_signal_proto; |
| case BPF_FUNC_send_signal_thread: |
| return &bpf_send_signal_thread_proto; |
| case BPF_FUNC_perf_event_read_value: |
| return &bpf_perf_event_read_value_proto; |
| case BPF_FUNC_get_ns_current_pid_tgid: |
| return &bpf_get_ns_current_pid_tgid_proto; |
| case BPF_FUNC_ringbuf_output: |
| return &bpf_ringbuf_output_proto; |
| case BPF_FUNC_ringbuf_reserve: |
| return &bpf_ringbuf_reserve_proto; |
| case BPF_FUNC_ringbuf_submit: |
| return &bpf_ringbuf_submit_proto; |
| case BPF_FUNC_ringbuf_discard: |
| return &bpf_ringbuf_discard_proto; |
| case BPF_FUNC_ringbuf_query: |
| return &bpf_ringbuf_query_proto; |
| case BPF_FUNC_jiffies64: |
| return &bpf_jiffies64_proto; |
| case BPF_FUNC_get_task_stack: |
| return &bpf_get_task_stack_proto; |
| case BPF_FUNC_copy_from_user: |
| return &bpf_copy_from_user_proto; |
| case BPF_FUNC_copy_from_user_task: |
| return &bpf_copy_from_user_task_proto; |
| case BPF_FUNC_snprintf_btf: |
| return &bpf_snprintf_btf_proto; |
| case BPF_FUNC_per_cpu_ptr: |
| return &bpf_per_cpu_ptr_proto; |
| case BPF_FUNC_this_cpu_ptr: |
| return &bpf_this_cpu_ptr_proto; |
| case BPF_FUNC_task_storage_get: |
| if (bpf_prog_check_recur(prog)) |
| return &bpf_task_storage_get_recur_proto; |
| return &bpf_task_storage_get_proto; |
| case BPF_FUNC_task_storage_delete: |
| if (bpf_prog_check_recur(prog)) |
| return &bpf_task_storage_delete_recur_proto; |
| return &bpf_task_storage_delete_proto; |
| case BPF_FUNC_for_each_map_elem: |
| return &bpf_for_each_map_elem_proto; |
| case BPF_FUNC_snprintf: |
| return &bpf_snprintf_proto; |
| case BPF_FUNC_get_func_ip: |
| return &bpf_get_func_ip_proto_tracing; |
| case BPF_FUNC_get_branch_snapshot: |
| return &bpf_get_branch_snapshot_proto; |
| case BPF_FUNC_find_vma: |
| return &bpf_find_vma_proto; |
| case BPF_FUNC_trace_vprintk: |
| return bpf_get_trace_vprintk_proto(); |
| default: |
| return bpf_base_func_proto(func_id, prog); |
| } |
| } |
| |
| static const struct bpf_func_proto * |
| kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto; |
| #ifdef CONFIG_BPF_KPROBE_OVERRIDE |
| case BPF_FUNC_override_return: |
| return &bpf_override_return_proto; |
| #endif |
| case BPF_FUNC_get_func_ip: |
| if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) |
| return &bpf_get_func_ip_proto_kprobe_multi; |
| if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) |
| return &bpf_get_func_ip_proto_uprobe_multi; |
| return &bpf_get_func_ip_proto_kprobe; |
| case BPF_FUNC_get_attach_cookie: |
| if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) |
| return &bpf_get_attach_cookie_proto_kmulti; |
| if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) |
| return &bpf_get_attach_cookie_proto_umulti; |
| return &bpf_get_attach_cookie_proto_trace; |
| default: |
| return bpf_tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| /* bpf+kprobe programs can access fields of 'struct pt_regs' */ |
| static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| if (off < 0 || off >= sizeof(struct pt_regs)) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) |
| return false; |
| /* |
| * Assertion for 32 bit to make sure last 8 byte access |
| * (BPF_DW) to the last 4 byte member is disallowed. |
| */ |
| if (off + size > sizeof(struct pt_regs)) |
| return false; |
| |
| return true; |
| } |
| |
| const struct bpf_verifier_ops kprobe_verifier_ops = { |
| .get_func_proto = kprobe_prog_func_proto, |
| .is_valid_access = kprobe_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops kprobe_prog_ops = { |
| }; |
| |
| BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map, |
| u64, flags, void *, data, u64, size) |
| { |
| struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| |
| /* |
| * r1 points to perf tracepoint buffer where first 8 bytes are hidden |
| * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it |
| * from there and call the same bpf_perf_event_output() helper inline. |
| */ |
| return ____bpf_perf_event_output(regs, map, flags, data, size); |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_output_proto_tp = { |
| .func = bpf_perf_event_output_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map, |
| u64, flags) |
| { |
| struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| |
| /* |
| * Same comment as in bpf_perf_event_output_tp(), only that this time |
| * the other helper's function body cannot be inlined due to being |
| * external, thus we need to call raw helper function. |
| */ |
| return bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| flags, 0, 0); |
| } |
| |
| static const struct bpf_func_proto bpf_get_stackid_proto_tp = { |
| .func = bpf_get_stackid_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size, |
| u64, flags) |
| { |
| struct pt_regs *regs = *(struct pt_regs **)tp_buff; |
| |
| return bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| (unsigned long) size, flags, 0); |
| } |
| |
| static const struct bpf_func_proto bpf_get_stack_proto_tp = { |
| .func = bpf_get_stack_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static const struct bpf_func_proto * |
| tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto_tp; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto_tp; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto_tp; |
| case BPF_FUNC_get_attach_cookie: |
| return &bpf_get_attach_cookie_proto_trace; |
| default: |
| return bpf_tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) |
| return false; |
| |
| BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64)); |
| return true; |
| } |
| |
| const struct bpf_verifier_ops tracepoint_verifier_ops = { |
| .get_func_proto = tp_prog_func_proto, |
| .is_valid_access = tp_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops tracepoint_prog_ops = { |
| }; |
| |
| BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx, |
| struct bpf_perf_event_value *, buf, u32, size) |
| { |
| int err = -EINVAL; |
| |
| if (unlikely(size != sizeof(struct bpf_perf_event_value))) |
| goto clear; |
| err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled, |
| &buf->running); |
| if (unlikely(err)) |
| goto clear; |
| return 0; |
| clear: |
| memset(buf, 0, size); |
| return err; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_prog_read_value_proto = { |
| .func = bpf_perf_prog_read_value, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg3_type = ARG_CONST_SIZE, |
| }; |
| |
| BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, |
| void *, buf, u32, size, u64, flags) |
| { |
| static const u32 br_entry_size = sizeof(struct perf_branch_entry); |
| struct perf_branch_stack *br_stack = ctx->data->br_stack; |
| u32 to_copy; |
| |
| if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) |
| return -EINVAL; |
| |
| if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) |
| return -ENOENT; |
| |
| if (unlikely(!br_stack)) |
| return -ENOENT; |
| |
| if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE) |
| return br_stack->nr * br_entry_size; |
| |
| if (!buf || (size % br_entry_size != 0)) |
| return -EINVAL; |
| |
| to_copy = min_t(u32, br_stack->nr * br_entry_size, size); |
| memcpy(buf, br_stack->entries, to_copy); |
| |
| return to_copy; |
| } |
| |
| static const struct bpf_func_proto bpf_read_branch_records_proto = { |
| .func = bpf_read_branch_records, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_MEM_OR_NULL, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static const struct bpf_func_proto * |
| pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto_tp; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto_pe; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto_pe; |
| case BPF_FUNC_perf_prog_read_value: |
| return &bpf_perf_prog_read_value_proto; |
| case BPF_FUNC_read_branch_records: |
| return &bpf_read_branch_records_proto; |
| case BPF_FUNC_get_attach_cookie: |
| return &bpf_get_attach_cookie_proto_pe; |
| default: |
| return bpf_tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| /* |
| * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp |
| * to avoid potential recursive reuse issue when/if tracepoints are added |
| * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack. |
| * |
| * Since raw tracepoints run despite bpf_prog_active, support concurrent usage |
| * in normal, irq, and nmi context. |
| */ |
| struct bpf_raw_tp_regs { |
| struct pt_regs regs[3]; |
| }; |
| static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs); |
| static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level); |
| static struct pt_regs *get_bpf_raw_tp_regs(void) |
| { |
| struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs); |
| int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level); |
| |
| if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) { |
| this_cpu_dec(bpf_raw_tp_nest_level); |
| return ERR_PTR(-EBUSY); |
| } |
| |
| return &tp_regs->regs[nest_level - 1]; |
| } |
| |
| static void put_bpf_raw_tp_regs(void) |
| { |
| this_cpu_dec(bpf_raw_tp_nest_level); |
| } |
| |
| BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| struct bpf_map *, map, u64, flags, void *, data, u64, size) |
| { |
| struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| int ret; |
| |
| if (IS_ERR(regs)) |
| return PTR_ERR(regs); |
| |
| perf_fetch_caller_regs(regs); |
| ret = ____bpf_perf_event_output(regs, map, flags, data, size); |
| |
| put_bpf_raw_tp_regs(); |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = { |
| .func = bpf_perf_event_output_raw_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg5_type = ARG_CONST_SIZE_OR_ZERO, |
| }; |
| |
| extern const struct bpf_func_proto bpf_skb_output_proto; |
| extern const struct bpf_func_proto bpf_xdp_output_proto; |
| extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto; |
| |
| BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| struct bpf_map *, map, u64, flags) |
| { |
| struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| int ret; |
| |
| if (IS_ERR(regs)) |
| return PTR_ERR(regs); |
| |
| perf_fetch_caller_regs(regs); |
| /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */ |
| ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map, |
| flags, 0, 0); |
| put_bpf_raw_tp_regs(); |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = { |
| .func = bpf_get_stackid_raw_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args, |
| void *, buf, u32, size, u64, flags) |
| { |
| struct pt_regs *regs = get_bpf_raw_tp_regs(); |
| int ret; |
| |
| if (IS_ERR(regs)) |
| return PTR_ERR(regs); |
| |
| perf_fetch_caller_regs(regs); |
| ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, |
| (unsigned long) size, flags, 0); |
| put_bpf_raw_tp_regs(); |
| return ret; |
| } |
| |
| static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { |
| .func = bpf_get_stack_raw_tp, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, |
| .arg3_type = ARG_CONST_SIZE_OR_ZERO, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| static const struct bpf_func_proto * |
| raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| switch (func_id) { |
| case BPF_FUNC_perf_event_output: |
| return &bpf_perf_event_output_proto_raw_tp; |
| case BPF_FUNC_get_stackid: |
| return &bpf_get_stackid_proto_raw_tp; |
| case BPF_FUNC_get_stack: |
| return &bpf_get_stack_proto_raw_tp; |
| default: |
| return bpf_tracing_func_proto(func_id, prog); |
| } |
| } |
| |
| const struct bpf_func_proto * |
| tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) |
| { |
| const struct bpf_func_proto *fn; |
| |
| switch (func_id) { |
| #ifdef CONFIG_NET |
| case BPF_FUNC_skb_output: |
| return &bpf_skb_output_proto; |
| case BPF_FUNC_xdp_output: |
| return &bpf_xdp_output_proto; |
| case BPF_FUNC_skc_to_tcp6_sock: |
| return &bpf_skc_to_tcp6_sock_proto; |
| case BPF_FUNC_skc_to_tcp_sock: |
| return &bpf_skc_to_tcp_sock_proto; |
| case BPF_FUNC_skc_to_tcp_timewait_sock: |
| return &bpf_skc_to_tcp_timewait_sock_proto; |
| case BPF_FUNC_skc_to_tcp_request_sock: |
| return &bpf_skc_to_tcp_request_sock_proto; |
| case BPF_FUNC_skc_to_udp6_sock: |
| return &bpf_skc_to_udp6_sock_proto; |
| case BPF_FUNC_skc_to_unix_sock: |
| return &bpf_skc_to_unix_sock_proto; |
| case BPF_FUNC_skc_to_mptcp_sock: |
| return &bpf_skc_to_mptcp_sock_proto; |
| case BPF_FUNC_sk_storage_get: |
| return &bpf_sk_storage_get_tracing_proto; |
| case BPF_FUNC_sk_storage_delete: |
| return &bpf_sk_storage_delete_tracing_proto; |
| case BPF_FUNC_sock_from_file: |
| return &bpf_sock_from_file_proto; |
| case BPF_FUNC_get_socket_cookie: |
| return &bpf_get_socket_ptr_cookie_proto; |
| case BPF_FUNC_xdp_get_buff_len: |
| return &bpf_xdp_get_buff_len_trace_proto; |
| #endif |
| case BPF_FUNC_seq_printf: |
| return prog->expected_attach_type == BPF_TRACE_ITER ? |
| &bpf_seq_printf_proto : |
| NULL; |
| case BPF_FUNC_seq_write: |
| return prog->expected_attach_type == BPF_TRACE_ITER ? |
| &bpf_seq_write_proto : |
| NULL; |
| case BPF_FUNC_seq_printf_btf: |
| return prog->expected_attach_type == BPF_TRACE_ITER ? |
| &bpf_seq_printf_btf_proto : |
| NULL; |
| case BPF_FUNC_d_path: |
| return &bpf_d_path_proto; |
| case BPF_FUNC_get_func_arg: |
| return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; |
| case BPF_FUNC_get_func_ret: |
| return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; |
| case BPF_FUNC_get_func_arg_cnt: |
| return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; |
| case BPF_FUNC_get_attach_cookie: |
| return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL; |
| default: |
| fn = raw_tp_prog_func_proto(func_id, prog); |
| if (!fn && prog->expected_attach_type == BPF_TRACE_ITER) |
| fn = bpf_iter_get_func_proto(func_id, prog); |
| return fn; |
| } |
| } |
| |
| static bool raw_tp_prog_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| return bpf_tracing_ctx_access(off, size, type); |
| } |
| |
| static bool tracing_prog_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| return bpf_tracing_btf_ctx_access(off, size, type, prog, info); |
| } |
| |
| int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog, |
| const union bpf_attr *kattr, |
| union bpf_attr __user *uattr) |
| { |
| return -ENOTSUPP; |
| } |
| |
| const struct bpf_verifier_ops raw_tracepoint_verifier_ops = { |
| .get_func_proto = raw_tp_prog_func_proto, |
| .is_valid_access = raw_tp_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops raw_tracepoint_prog_ops = { |
| #ifdef CONFIG_NET |
| .test_run = bpf_prog_test_run_raw_tp, |
| #endif |
| }; |
| |
| const struct bpf_verifier_ops tracing_verifier_ops = { |
| .get_func_proto = tracing_prog_func_proto, |
| .is_valid_access = tracing_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops tracing_prog_ops = { |
| .test_run = bpf_prog_test_run_tracing, |
| }; |
| |
| static bool raw_tp_writable_prog_is_valid_access(int off, int size, |
| enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| if (off == 0) { |
| if (size != sizeof(u64) || type != BPF_READ) |
| return false; |
| info->reg_type = PTR_TO_TP_BUFFER; |
| } |
| return raw_tp_prog_is_valid_access(off, size, type, prog, info); |
| } |
| |
| const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = { |
| .get_func_proto = raw_tp_prog_func_proto, |
| .is_valid_access = raw_tp_writable_prog_is_valid_access, |
| }; |
| |
| const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = { |
| }; |
| |
| static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type, |
| const struct bpf_prog *prog, |
| struct bpf_insn_access_aux *info) |
| { |
| const int size_u64 = sizeof(u64); |
| |
| if (off < 0 || off >= sizeof(struct bpf_perf_event_data)) |
| return false; |
| if (type != BPF_READ) |
| return false; |
| if (off % size != 0) { |
| if (sizeof(unsigned long) != 4) |
| return false; |
| if (size != 8) |
| return false; |
| if (off % size != 4) |
| return false; |
| } |
| |
| switch (off) { |
| case bpf_ctx_range(struct bpf_perf_event_data, sample_period): |
| bpf_ctx_record_field_size(info, size_u64); |
| if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| return false; |
| break; |
| case bpf_ctx_range(struct bpf_perf_event_data, addr): |
| bpf_ctx_record_field_size(info, size_u64); |
| if (!bpf_ctx_narrow_access_ok(off, size, size_u64)) |
| return false; |
| break; |
| default: |
| if (size != sizeof(long)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, |
| const struct bpf_insn *si, |
| struct bpf_insn *insn_buf, |
| struct bpf_prog *prog, u32 *target_size) |
| { |
| struct bpf_insn *insn = insn_buf; |
| |
| switch (si->off) { |
| case offsetof(struct bpf_perf_event_data, sample_period): |
| *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| data), si->dst_reg, si->src_reg, |
| offsetof(struct bpf_perf_event_data_kern, data)); |
| *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| bpf_target_off(struct perf_sample_data, period, 8, |
| target_size)); |
| break; |
| case offsetof(struct bpf_perf_event_data, addr): |
| *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| data), si->dst_reg, si->src_reg, |
| offsetof(struct bpf_perf_event_data_kern, data)); |
| *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, |
| bpf_target_off(struct perf_sample_data, addr, 8, |
| target_size)); |
| break; |
| default: |
| *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern, |
| regs), si->dst_reg, si->src_reg, |
| offsetof(struct bpf_perf_event_data_kern, regs)); |
| *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg, |
| si->off); |
| break; |
| } |
| |
| return insn - insn_buf; |
| } |
| |
| const struct bpf_verifier_ops perf_event_verifier_ops = { |
| .get_func_proto = pe_prog_func_proto, |
| .is_valid_access = pe_prog_is_valid_access, |
| .convert_ctx_access = pe_prog_convert_ctx_access, |
| }; |
| |
| const struct bpf_prog_ops perf_event_prog_ops = { |
| }; |
| |
| static DEFINE_MUTEX(bpf_event_mutex); |
| |
| #define BPF_TRACE_MAX_PROGS 64 |
| |
| int perf_event_attach_bpf_prog(struct perf_event *event, |
| struct bpf_prog *prog, |
| u64 bpf_cookie) |
| { |
| struct bpf_prog_array *old_array; |
| struct bpf_prog_array *new_array; |
| int ret = -EEXIST; |
| |
| /* |
| * Kprobe override only works if they are on the function entry, |
| * and only if they are on the opt-in list. |
| */ |
| if (prog->kprobe_override && |
| (!trace_kprobe_on_func_entry(event->tp_event) || |
| !trace_kprobe_error_injectable(event->tp_event))) |
| return -EINVAL; |
| |
| mutex_lock(&bpf_event_mutex); |
| |
| if (event->prog) |
| goto unlock; |
| |
| old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| if (old_array && |
| bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) { |
| ret = -E2BIG; |
| goto unlock; |
| } |
| |
| ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array); |
| if (ret < 0) |
| goto unlock; |
| |
| /* set the new array to event->tp_event and set event->prog */ |
| event->prog = prog; |
| event->bpf_cookie = bpf_cookie; |
| rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| bpf_prog_array_free_sleepable(old_array); |
| |
| unlock: |
| mutex_unlock(&bpf_event_mutex); |
| return ret; |
| } |
| |
| void perf_event_detach_bpf_prog(struct perf_event *event) |
| { |
| struct bpf_prog_array *old_array; |
| struct bpf_prog_array *new_array; |
| int ret; |
| |
| mutex_lock(&bpf_event_mutex); |
| |
| if (!event->prog) |
| goto unlock; |
| |
| old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); |
| if (ret == -ENOENT) |
| goto unlock; |
| if (ret < 0) { |
| bpf_prog_array_delete_safe(old_array, event->prog); |
| } else { |
| rcu_assign_pointer(event->tp_event->prog_array, new_array); |
| bpf_prog_array_free_sleepable(old_array); |
| } |
| |
| bpf_prog_put(event->prog); |
| event->prog = NULL; |
| |
| unlock: |
| mutex_unlock(&bpf_event_mutex); |
| } |
| |
| int perf_event_query_prog_array(struct perf_event *event, void __user *info) |
| { |
| struct perf_event_query_bpf __user *uquery = info; |
| struct perf_event_query_bpf query = {}; |
| struct bpf_prog_array *progs; |
| u32 *ids, prog_cnt, ids_len; |
| int ret; |
| |
| if (!perfmon_capable()) |
| return -EPERM; |
| if (event->attr.type != PERF_TYPE_TRACEPOINT) |
| return -EINVAL; |
| if (copy_from_user(&query, uquery, sizeof(query))) |
| return -EFAULT; |
| |
| ids_len = query.ids_len; |
| if (ids_len > BPF_TRACE_MAX_PROGS) |
| return -E2BIG; |
| ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN); |
| if (!ids) |
| return -ENOMEM; |
| /* |
| * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which |
| * is required when user only wants to check for uquery->prog_cnt. |
| * There is no need to check for it since the case is handled |
| * gracefully in bpf_prog_array_copy_info. |
| */ |
| |
| mutex_lock(&bpf_event_mutex); |
| progs = bpf_event_rcu_dereference(event->tp_event->prog_array); |
| ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt); |
| mutex_unlock(&bpf_event_mutex); |
| |
| if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) || |
| copy_to_user(uquery->ids, ids, ids_len * sizeof(u32))) |
| ret = -EFAULT; |
| |
| kfree(ids); |
| return ret; |
| } |
| |
| extern struct bpf_raw_event_map __start__bpf_raw_tp[]; |
| extern struct bpf_raw_event_map __stop__bpf_raw_tp[]; |
| |
| struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name) |
| { |
| struct bpf_raw_event_map *btp = __start__bpf_raw_tp; |
| |
| for (; btp < __stop__bpf_raw_tp; btp++) { |
| if (!strcmp(btp->tp->name, name)) |
| return btp; |
| } |
| |
| return bpf_get_raw_tracepoint_module(name); |
| } |
| |
| void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) |
| { |
| struct module *mod; |
| |
| preempt_disable(); |
| mod = __module_address((unsigned long)btp); |
| module_put(mod); |
| preempt_enable(); |
| } |
| |
| static __always_inline |
| void __bpf_trace_run(struct bpf_prog *prog, u64 *args) |
| { |
| cant_sleep(); |
| if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { |
| bpf_prog_inc_misses_counter(prog); |
| goto out; |
| } |
| rcu_read_lock(); |
| (void) bpf_prog_run(prog, args); |
| rcu_read_unlock(); |
| out: |
| this_cpu_dec(*(prog->active)); |
| } |
| |
| #define UNPACK(...) __VA_ARGS__ |
| #define REPEAT_1(FN, DL, X, ...) FN(X) |
| #define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__) |
| #define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__) |
| #define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__) |
| #define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__) |
| #define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__) |
| #define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__) |
| #define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__) |
| #define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__) |
| #define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__) |
| #define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__) |
| #define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__) |
| #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) |
| |
| #define SARG(X) u64 arg##X |
| #define COPY(X) args[X] = arg##X |
| |
| #define __DL_COM (,) |
| #define __DL_SEM (;) |
| |
| #define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 |
| |
| #define BPF_TRACE_DEFN_x(x) \ |
| void bpf_trace_run##x(struct bpf_prog *prog, \ |
| REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ |
| { \ |
| u64 args[x]; \ |
| REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ |
| __bpf_trace_run(prog, args); \ |
| } \ |
| EXPORT_SYMBOL_GPL(bpf_trace_run##x) |
| BPF_TRACE_DEFN_x(1); |
| BPF_TRACE_DEFN_x(2); |
| BPF_TRACE_DEFN_x(3); |
| BPF_TRACE_DEFN_x(4); |
| BPF_TRACE_DEFN_x(5); |
| BPF_TRACE_DEFN_x(6); |
| BPF_TRACE_DEFN_x(7); |
| BPF_TRACE_DEFN_x(8); |
| BPF_TRACE_DEFN_x(9); |
| BPF_TRACE_DEFN_x(10); |
| BPF_TRACE_DEFN_x(11); |
| BPF_TRACE_DEFN_x(12); |
| |
| static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| { |
| struct tracepoint *tp = btp->tp; |
| |
| /* |
| * check that program doesn't access arguments beyond what's |
| * available in this tracepoint |
| */ |
| if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64)) |
| return -EINVAL; |
| |
| if (prog->aux->max_tp_access > btp->writable_size) |
| return -EINVAL; |
| |
| return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, |
| prog); |
| } |
| |
| int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| { |
| return __bpf_probe_register(btp, prog); |
| } |
| |
| int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) |
| { |
| return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog); |
| } |
| |
| int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, |
| u32 *fd_type, const char **buf, |
| u64 *probe_offset, u64 *probe_addr, |
| unsigned long *missed) |
| { |
| bool is_tracepoint, is_syscall_tp; |
| struct bpf_prog *prog; |
| int flags, err = 0; |
| |
| prog = event->prog; |
| if (!prog) |
| return -ENOENT; |
| |
| /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */ |
| if (prog->type == BPF_PROG_TYPE_PERF_EVENT) |
| return -EOPNOTSUPP; |
| |
| *prog_id = prog->aux->id; |
| flags = event->tp_event->flags; |
| is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT; |
| is_syscall_tp = is_syscall_trace_event(event->tp_event); |
| |
| if (is_tracepoint || is_syscall_tp) { |
| *buf = is_tracepoint ? event->tp_event->tp->name |
| : event->tp_event->name; |
| /* We allow NULL pointer for tracepoint */ |
| if (fd_type) |
| *fd_type = BPF_FD_TYPE_TRACEPOINT; |
| if (probe_offset) |
| *probe_offset = 0x0; |
| if (probe_addr) |
| *probe_addr = 0x0; |
| } else { |
| /* kprobe/uprobe */ |
| err = -EOPNOTSUPP; |
| #ifdef CONFIG_KPROBE_EVENTS |
| if (flags & TRACE_EVENT_FL_KPROBE) |
| err = bpf_get_kprobe_info(event, fd_type, buf, |
| probe_offset, probe_addr, missed, |
| event->attr.type == PERF_TYPE_TRACEPOINT); |
| #endif |
| #ifdef CONFIG_UPROBE_EVENTS |
| if (flags & TRACE_EVENT_FL_UPROBE) |
| err = bpf_get_uprobe_info(event, fd_type, buf, |
| probe_offset, probe_addr, |
| event->attr.type == PERF_TYPE_TRACEPOINT); |
| #endif |
| } |
| |
| return err; |
| } |
| |
| static int __init send_signal_irq_work_init(void) |
| { |
| int cpu; |
| struct send_signal_irq_work *work; |
| |
| for_each_possible_cpu(cpu) { |
| work = per_cpu_ptr(&send_signal_work, cpu); |
| init_irq_work(&work->irq_work, do_bpf_send_signal); |
| } |
| return 0; |
| } |
| |
| subsys_initcall(send_signal_irq_work_init); |
| |
| #ifdef CONFIG_MODULES |
| static int bpf_event_notify(struct notifier_block *nb, unsigned long op, |
| void *module) |
| { |
| struct bpf_trace_module *btm, *tmp; |
| struct module *mod = module; |
| int ret = 0; |
| |
| if (mod->num_bpf_raw_events == 0 || |
| (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) |
| goto out; |
| |
| mutex_lock(&bpf_module_mutex); |
| |
| switch (op) { |
| case MODULE_STATE_COMING: |
| btm = kzalloc(sizeof(*btm), GFP_KERNEL); |
| if (btm) { |
| btm->module = module; |
| list_add(&btm->list, &bpf_trace_modules); |
| } else { |
| ret = -ENOMEM; |
| } |
| break; |
| case MODULE_STATE_GOING: |
| list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) { |
| if (btm->module == module) { |
| list_del(&btm->list); |
| kfree(btm); |
| break; |
| } |
| } |
| break; |
| } |
| |
| mutex_unlock(&bpf_module_mutex); |
| |
| out: |
| return notifier_from_errno(ret); |
| } |
| |
| static struct notifier_block bpf_module_nb = { |
| .notifier_call = bpf_event_notify, |
| }; |
| |
| static int __init bpf_event_init(void) |
| { |
| register_module_notifier(&bpf_module_nb); |
| return 0; |
| } |
| |
| fs_initcall(bpf_event_init); |
| #endif /* CONFIG_MODULES */ |
| |
| #ifdef CONFIG_FPROBE |
| struct bpf_kprobe_multi_link { |
| struct bpf_link link; |
| struct fprobe fp; |
| unsigned long *addrs; |
| u64 *cookies; |
| u32 cnt; |
| u32 mods_cnt; |
| struct module **mods; |
| u32 flags; |
| }; |
| |
| struct bpf_kprobe_multi_run_ctx { |
| struct bpf_run_ctx run_ctx; |
| struct bpf_kprobe_multi_link *link; |
| unsigned long entry_ip; |
| }; |
| |
| struct user_syms { |
| const char **syms; |
| char *buf; |
| }; |
| |
| static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) |
| { |
| unsigned long __user usymbol; |
| const char **syms = NULL; |
| char *buf = NULL, *p; |
| int err = -ENOMEM; |
| unsigned int i; |
| |
| syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); |
| if (!syms) |
| goto error; |
| |
| buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); |
| if (!buf) |
| goto error; |
| |
| for (p = buf, i = 0; i < cnt; i++) { |
| if (__get_user(usymbol, usyms + i)) { |
| err = -EFAULT; |
| goto error; |
| } |
| err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); |
| if (err == KSYM_NAME_LEN) |
| err = -E2BIG; |
| if (err < 0) |
| goto error; |
| syms[i] = p; |
| p += err + 1; |
| } |
| |
| us->syms = syms; |
| us->buf = buf; |
| return 0; |
| |
| error: |
| if (err) { |
| kvfree(syms); |
| kvfree(buf); |
| } |
| return err; |
| } |
| |
| static void kprobe_multi_put_modules(struct module **mods, u32 cnt) |
| { |
| u32 i; |
| |
| for (i = 0; i < cnt; i++) |
| module_put(mods[i]); |
| } |
| |
| static void free_user_syms(struct user_syms *us) |
| { |
| kvfree(us->syms); |
| kvfree(us->buf); |
| } |
| |
| static void bpf_kprobe_multi_link_release(struct bpf_link *link) |
| { |
| struct bpf_kprobe_multi_link *kmulti_link; |
| |
| kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); |
| unregister_fprobe(&kmulti_link->fp); |
| kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); |
| } |
| |
| static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) |
| { |
| struct bpf_kprobe_multi_link *kmulti_link; |
| |
| kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); |
| kvfree(kmulti_link->addrs); |
| kvfree(kmulti_link->cookies); |
| kfree(kmulti_link->mods); |
| kfree(kmulti_link); |
| } |
| |
| static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, |
| struct bpf_link_info *info) |
| { |
| u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies); |
| u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); |
| struct bpf_kprobe_multi_link *kmulti_link; |
| u32 ucount = info->kprobe_multi.count; |
| int err = 0, i; |
| |
| if (!uaddrs ^ !ucount) |
| return -EINVAL; |
| if (ucookies && !ucount) |
| return -EINVAL; |
| |
| kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); |
| info->kprobe_multi.count = kmulti_link->cnt; |
| info->kprobe_multi.flags = kmulti_link->flags; |
| info->kprobe_multi.missed = kmulti_link->fp.nmissed; |
| |
| if (!uaddrs) |
| return 0; |
| if (ucount < kmulti_link->cnt) |
| err = -ENOSPC; |
| else |
| ucount = kmulti_link->cnt; |
| |
| if (ucookies) { |
| if (kmulti_link->cookies) { |
| if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) |
| return -EFAULT; |
| } else { |
| for (i = 0; i < ucount; i++) { |
| if (put_user(0, ucookies + i)) |
| return -EFAULT; |
| } |
| } |
| } |
| |
| if (kallsyms_show_value(current_cred())) { |
| if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) |
| return -EFAULT; |
| } else { |
| for (i = 0; i < ucount; i++) { |
| if (put_user(0, uaddrs + i)) |
| return -EFAULT; |
| } |
| } |
| return err; |
| } |
| |
| static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { |
| .release = bpf_kprobe_multi_link_release, |
| .dealloc_deferred = bpf_kprobe_multi_link_dealloc, |
| .fill_link_info = bpf_kprobe_multi_link_fill_link_info, |
| }; |
| |
| static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) |
| { |
| const struct bpf_kprobe_multi_link *link = priv; |
| unsigned long *addr_a = a, *addr_b = b; |
| u64 *cookie_a, *cookie_b; |
| |
| cookie_a = link->cookies + (addr_a - link->addrs); |
| cookie_b = link->cookies + (addr_b - link->addrs); |
| |
| /* swap addr_a/addr_b and cookie_a/cookie_b values */ |
| swap(*addr_a, *addr_b); |
| swap(*cookie_a, *cookie_b); |
| } |
| |
| static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) |
| { |
| const unsigned long *addr_a = a, *addr_b = b; |
| |
| if (*addr_a == *addr_b) |
| return 0; |
| return *addr_a < *addr_b ? -1 : 1; |
| } |
| |
| static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) |
| { |
| return bpf_kprobe_multi_addrs_cmp(a, b); |
| } |
| |
| static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| { |
| struct bpf_kprobe_multi_run_ctx *run_ctx; |
| struct bpf_kprobe_multi_link *link; |
| u64 *cookie, entry_ip; |
| unsigned long *addr; |
| |
| if (WARN_ON_ONCE(!ctx)) |
| return 0; |
| run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); |
| link = run_ctx->link; |
| if (!link->cookies) |
| return 0; |
| entry_ip = run_ctx->entry_ip; |
| addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), |
| bpf_kprobe_multi_addrs_cmp); |
| if (!addr) |
| return 0; |
| cookie = link->cookies + (addr - link->addrs); |
| return *cookie; |
| } |
| |
| static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| { |
| struct bpf_kprobe_multi_run_ctx *run_ctx; |
| |
| run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); |
| return run_ctx->entry_ip; |
| } |
| |
| static int |
| kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, |
| unsigned long entry_ip, struct pt_regs *regs) |
| { |
| struct bpf_kprobe_multi_run_ctx run_ctx = { |
| .link = link, |
| .entry_ip = entry_ip, |
| }; |
| struct bpf_run_ctx *old_run_ctx; |
| int err; |
| |
| if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { |
| bpf_prog_inc_misses_counter(link->link.prog); |
| err = 0; |
| goto out; |
| } |
| |
| migrate_disable(); |
| rcu_read_lock(); |
| old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); |
| err = bpf_prog_run(link->link.prog, regs); |
| bpf_reset_run_ctx(old_run_ctx); |
| rcu_read_unlock(); |
| migrate_enable(); |
| |
| out: |
| __this_cpu_dec(bpf_prog_active); |
| return err; |
| } |
| |
| static int |
| kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, |
| unsigned long ret_ip, struct pt_regs *regs, |
| void *data) |
| { |
| struct bpf_kprobe_multi_link *link; |
| |
| link = container_of(fp, struct bpf_kprobe_multi_link, fp); |
| kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); |
| return 0; |
| } |
| |
| static void |
| kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, |
| unsigned long ret_ip, struct pt_regs *regs, |
| void *data) |
| { |
| struct bpf_kprobe_multi_link *link; |
| |
| link = container_of(fp, struct bpf_kprobe_multi_link, fp); |
| kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); |
| } |
| |
| static int symbols_cmp_r(const void *a, const void *b, const void *priv) |
| { |
| const char **str_a = (const char **) a; |
| const char **str_b = (const char **) b; |
| |
| return strcmp(*str_a, *str_b); |
| } |
| |
| struct multi_symbols_sort { |
| const char **funcs; |
| u64 *cookies; |
| }; |
| |
| static void symbols_swap_r(void *a, void *b, int size, const void *priv) |
| { |
| const struct multi_symbols_sort *data = priv; |
| const char **name_a = a, **name_b = b; |
| |
| swap(*name_a, *name_b); |
| |
| /* If defined, swap also related cookies. */ |
| if (data->cookies) { |
| u64 *cookie_a, *cookie_b; |
| |
| cookie_a = data->cookies + (name_a - data->funcs); |
| cookie_b = data->cookies + (name_b - data->funcs); |
| swap(*cookie_a, *cookie_b); |
| } |
| } |
| |
| struct modules_array { |
| struct module **mods; |
| int mods_cnt; |
| int mods_cap; |
| }; |
| |
| static int add_module(struct modules_array *arr, struct module *mod) |
| { |
| struct module **mods; |
| |
| if (arr->mods_cnt == arr->mods_cap) { |
| arr->mods_cap = max(16, arr->mods_cap * 3 / 2); |
| mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); |
| if (!mods) |
| return -ENOMEM; |
| arr->mods = mods; |
| } |
| |
| arr->mods[arr->mods_cnt] = mod; |
| arr->mods_cnt++; |
| return 0; |
| } |
| |
| static bool has_module(struct modules_array *arr, struct module *mod) |
| { |
| int i; |
| |
| for (i = arr->mods_cnt - 1; i >= 0; i--) { |
| if (arr->mods[i] == mod) |
| return true; |
| } |
| return false; |
| } |
| |
| static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) |
| { |
| struct modules_array arr = {}; |
| u32 i, err = 0; |
| |
| for (i = 0; i < addrs_cnt; i++) { |
| struct module *mod; |
| |
| preempt_disable(); |
| mod = __module_address(addrs[i]); |
| /* Either no module or we it's already stored */ |
| if (!mod || has_module(&arr, mod)) { |
| preempt_enable(); |
| continue; |
| } |
| if (!try_module_get(mod)) |
| err = -EINVAL; |
| preempt_enable(); |
| if (err) |
| break; |
| err = add_module(&arr, mod); |
| if (err) { |
| module_put(mod); |
| break; |
| } |
| } |
| |
| /* We return either err < 0 in case of error, ... */ |
| if (err) { |
| kprobe_multi_put_modules(arr.mods, arr.mods_cnt); |
| kfree(arr.mods); |
| return err; |
| } |
| |
| /* or number of modules found if everything is ok. */ |
| *mods = arr.mods; |
| return arr.mods_cnt; |
| } |
| |
| static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) |
| { |
| u32 i; |
| |
| for (i = 0; i < cnt; i++) { |
| if (!within_error_injection_list(addrs[i])) |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| { |
| struct bpf_kprobe_multi_link *link = NULL; |
| struct bpf_link_primer link_primer; |
| void __user *ucookies; |
| unsigned long *addrs; |
| u32 flags, cnt, size; |
| void __user *uaddrs; |
| u64 *cookies = NULL; |
| void __user *usyms; |
| int err; |
| |
| /* no support for 32bit archs yet */ |
| if (sizeof(u64) != sizeof(void *)) |
| return -EOPNOTSUPP; |
| |
| if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) |
| return -EINVAL; |
| |
| flags = attr->link_create.kprobe_multi.flags; |
| if (flags & ~BPF_F_KPROBE_MULTI_RETURN) |
| return -EINVAL; |
| |
| uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); |
| usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); |
| if (!!uaddrs == !!usyms) |
| return -EINVAL; |
| |
| cnt = attr->link_create.kprobe_multi.cnt; |
| if (!cnt) |
| return -EINVAL; |
| if (cnt > MAX_KPROBE_MULTI_CNT) |
| return -E2BIG; |
| |
| size = cnt * sizeof(*addrs); |
| addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); |
| if (!addrs) |
| return -ENOMEM; |
| |
| ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); |
| if (ucookies) { |
| cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL); |
| if (!cookies) { |
| err = -ENOMEM; |
| goto error; |
| } |
| if (copy_from_user(cookies, ucookies, size)) { |
| err = -EFAULT; |
| goto error; |
| } |
| } |
| |
| if (uaddrs) { |
| if (copy_from_user(addrs, uaddrs, size)) { |
| err = -EFAULT; |
| goto error; |
| } |
| } else { |
| struct multi_symbols_sort data = { |
| .cookies = cookies, |
| }; |
| struct user_syms us; |
| |
| err = copy_user_syms(&us, usyms, cnt); |
| if (err) |
| goto error; |
| |
| if (cookies) |
| data.funcs = us.syms; |
| |
| sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r, |
| symbols_swap_r, &data); |
| |
| err = ftrace_lookup_symbols(us.syms, cnt, addrs); |
| free_user_syms(&us); |
| if (err) |
| goto error; |
| } |
| |
| if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) { |
| err = -EINVAL; |
| goto error; |
| } |
| |
| link = kzalloc(sizeof(*link), GFP_KERNEL); |
| if (!link) { |
| err = -ENOMEM; |
| goto error; |
| } |
| |
| bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, |
| &bpf_kprobe_multi_link_lops, prog); |
| |
| err = bpf_link_prime(&link->link, &link_primer); |
| if (err) |
| goto error; |
| |
| if (flags & BPF_F_KPROBE_MULTI_RETURN) |
| link->fp.exit_handler = kprobe_multi_link_exit_handler; |
| else |
| link->fp.entry_handler = kprobe_multi_link_handler; |
| |
| link->addrs = addrs; |
| link->cookies = cookies; |
| link->cnt = cnt; |
| link->flags = flags; |
| |
| if (cookies) { |
| /* |
| * Sorting addresses will trigger sorting cookies as well |
| * (check bpf_kprobe_multi_cookie_swap). This way we can |
| * find cookie based on the address in bpf_get_attach_cookie |
| * helper. |
| */ |
| sort_r(addrs, cnt, sizeof(*addrs), |
| bpf_kprobe_multi_cookie_cmp, |
| bpf_kprobe_multi_cookie_swap, |
| link); |
| } |
| |
| err = get_modules_for_addrs(&link->mods, addrs, cnt); |
| if (err < 0) { |
| bpf_link_cleanup(&link_primer); |
| return err; |
| } |
| link->mods_cnt = err; |
| |
| err = register_fprobe_ips(&link->fp, addrs, cnt); |
| if (err) { |
| kprobe_multi_put_modules(link->mods, link->mods_cnt); |
| bpf_link_cleanup(&link_primer); |
| return err; |
| } |
| |
| return bpf_link_settle(&link_primer); |
| |
| error: |
| kfree(link); |
| kvfree(addrs); |
| kvfree(cookies); |
| return err; |
| } |
| #else /* !CONFIG_FPROBE */ |
| int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| { |
| return -EOPNOTSUPP; |
| } |
| static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| { |
| return 0; |
| } |
| static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| { |
| return 0; |
| } |
| #endif |
| |
| #ifdef CONFIG_UPROBES |
| struct bpf_uprobe_multi_link; |
| |
| struct bpf_uprobe { |
| struct bpf_uprobe_multi_link *link; |
| loff_t offset; |
| unsigned long ref_ctr_offset; |
| u64 cookie; |
| struct uprobe_consumer consumer; |
| }; |
| |
| struct bpf_uprobe_multi_link { |
| struct path path; |
| struct bpf_link link; |
| u32 cnt; |
| u32 flags; |
| struct bpf_uprobe *uprobes; |
| struct task_struct *task; |
| }; |
| |
| struct bpf_uprobe_multi_run_ctx { |
| struct bpf_run_ctx run_ctx; |
| unsigned long entry_ip; |
| struct bpf_uprobe *uprobe; |
| }; |
| |
| static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes, |
| u32 cnt) |
| { |
| u32 i; |
| |
| for (i = 0; i < cnt; i++) { |
| uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, |
| &uprobes[i].consumer); |
| } |
| } |
| |
| static void bpf_uprobe_multi_link_release(struct bpf_link *link) |
| { |
| struct bpf_uprobe_multi_link *umulti_link; |
| |
| umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); |
| bpf_uprobe_unregister(&umulti_link->path, umulti_link->uprobes, umulti_link->cnt); |
| if (umulti_link->task) |
| put_task_struct(umulti_link->task); |
| path_put(&umulti_link->path); |
| } |
| |
| static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link) |
| { |
| struct bpf_uprobe_multi_link *umulti_link; |
| |
| umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); |
| kvfree(umulti_link->uprobes); |
| kfree(umulti_link); |
| } |
| |
| static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, |
| struct bpf_link_info *info) |
| { |
| u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets); |
| u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies); |
| u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets); |
| u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path); |
| u32 upath_size = info->uprobe_multi.path_size; |
| struct bpf_uprobe_multi_link *umulti_link; |
| u32 ucount = info->uprobe_multi.count; |
| int err = 0, i; |
| long left; |
| |
| if (!upath ^ !upath_size) |
| return -EINVAL; |
| |
| if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount) |
| return -EINVAL; |
| |
| umulti_link = container_of(link, struct bpf_uprobe_multi_link, link); |
| info->uprobe_multi.count = umulti_link->cnt; |
| info->uprobe_multi.flags = umulti_link->flags; |
| info->uprobe_multi.pid = umulti_link->task ? |
| task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0; |
| |
| if (upath) { |
| char *p, *buf; |
| |
| upath_size = min_t(u32, upath_size, PATH_MAX); |
| |
| buf = kmalloc(upath_size, GFP_KERNEL); |
| if (!buf) |
| return -ENOMEM; |
| p = d_path(&umulti_link->path, buf, upath_size); |
| if (IS_ERR(p)) { |
| kfree(buf); |
| return PTR_ERR(p); |
| } |
| upath_size = buf + upath_size - p; |
| left = copy_to_user(upath, p, upath_size); |
| kfree(buf); |
| if (left) |
| return -EFAULT; |
| info->uprobe_multi.path_size = upath_size; |
| } |
| |
| if (!uoffsets && !ucookies && !uref_ctr_offsets) |
| return 0; |
| |
| if (ucount < umulti_link->cnt) |
| err = -ENOSPC; |
| else |
| ucount = umulti_link->cnt; |
| |
| for (i = 0; i < ucount; i++) { |
| if (uoffsets && |
| put_user(umulti_link->uprobes[i].offset, uoffsets + i)) |
| return -EFAULT; |
| if (uref_ctr_offsets && |
| put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) |
| return -EFAULT; |
| if (ucookies && |
| put_user(umulti_link->uprobes[i].cookie, ucookies + i)) |
| return -EFAULT; |
| } |
| |
| return err; |
| } |
| |
| static const struct bpf_link_ops bpf_uprobe_multi_link_lops = { |
| .release = bpf_uprobe_multi_link_release, |
| .dealloc_deferred = bpf_uprobe_multi_link_dealloc, |
| .fill_link_info = bpf_uprobe_multi_link_fill_link_info, |
| }; |
| |
| static int uprobe_prog_run(struct bpf_uprobe *uprobe, |
| unsigned long entry_ip, |
| struct pt_regs *regs) |
| { |
| struct bpf_uprobe_multi_link *link = uprobe->link; |
| struct bpf_uprobe_multi_run_ctx run_ctx = { |
| .entry_ip = entry_ip, |
| .uprobe = uprobe, |
| }; |
| struct bpf_prog *prog = link->link.prog; |
| bool sleepable = prog->sleepable; |
| struct bpf_run_ctx *old_run_ctx; |
| int err = 0; |
| |
| if (link->task && current != link->task) |
| return 0; |
| |
| if (sleepable) |
| rcu_read_lock_trace(); |
| else |
| rcu_read_lock(); |
| |
| migrate_disable(); |
| |
| old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); |
| err = bpf_prog_run(link->link.prog, regs); |
| bpf_reset_run_ctx(old_run_ctx); |
| |
| migrate_enable(); |
| |
| if (sleepable) |
| rcu_read_unlock_trace(); |
| else |
| rcu_read_unlock(); |
| return err; |
| } |
| |
| static bool |
| uprobe_multi_link_filter(struct uprobe_consumer *con, enum uprobe_filter_ctx ctx, |
| struct mm_struct *mm) |
| { |
| struct bpf_uprobe *uprobe; |
| |
| uprobe = container_of(con, struct bpf_uprobe, consumer); |
| return uprobe->link->task->mm == mm; |
| } |
| |
| static int |
| uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs) |
| { |
| struct bpf_uprobe *uprobe; |
| |
| uprobe = container_of(con, struct bpf_uprobe, consumer); |
| return uprobe_prog_run(uprobe, instruction_pointer(regs), regs); |
| } |
| |
| static int |
| uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs) |
| { |
| struct bpf_uprobe *uprobe; |
| |
| uprobe = container_of(con, struct bpf_uprobe, consumer); |
| return uprobe_prog_run(uprobe, func, regs); |
| } |
| |
| static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| { |
| struct bpf_uprobe_multi_run_ctx *run_ctx; |
| |
| run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); |
| return run_ctx->entry_ip; |
| } |
| |
| static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| { |
| struct bpf_uprobe_multi_run_ctx *run_ctx; |
| |
| run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx); |
| return run_ctx->uprobe->cookie; |
| } |
| |
| int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| { |
| struct bpf_uprobe_multi_link *link = NULL; |
| unsigned long __user *uref_ctr_offsets; |
| struct bpf_link_primer link_primer; |
| struct bpf_uprobe *uprobes = NULL; |
| struct task_struct *task = NULL; |
| unsigned long __user *uoffsets; |
| u64 __user *ucookies; |
| void __user *upath; |
| u32 flags, cnt, i; |
| struct path path; |
| char *name; |
| pid_t pid; |
| int err; |
| |
| /* no support for 32bit archs yet */ |
| if (sizeof(u64) != sizeof(void *)) |
| return -EOPNOTSUPP; |
| |
| if (prog->expected_attach_type != BPF_TRACE_UPROBE_MULTI) |
| return -EINVAL; |
| |
| flags = attr->link_create.uprobe_multi.flags; |
| if (flags & ~BPF_F_UPROBE_MULTI_RETURN) |
| return -EINVAL; |
| |
| /* |
| * path, offsets and cnt are mandatory, |
| * ref_ctr_offsets and cookies are optional |
| */ |
| upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path); |
| uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets); |
| cnt = attr->link_create.uprobe_multi.cnt; |
| |
| if (!upath || !uoffsets || !cnt) |
| return -EINVAL; |
| if (cnt > MAX_UPROBE_MULTI_CNT) |
| return -E2BIG; |
| |
| uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets); |
| ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies); |
| |
| name = strndup_user(upath, PATH_MAX); |
| if (IS_ERR(name)) { |
| err = PTR_ERR(name); |
| return err; |
| } |
| |
| err = kern_path(name, LOOKUP_FOLLOW, &path); |
| kfree(name); |
| if (err) |
| return err; |
| |
| if (!d_is_reg(path.dentry)) { |
| err = -EBADF; |
| goto error_path_put; |
| } |
| |
| pid = attr->link_create.uprobe_multi.pid; |
| if (pid) { |
| rcu_read_lock(); |
| task = get_pid_task(find_vpid(pid), PIDTYPE_PID); |
| rcu_read_unlock(); |
| if (!task) { |
| err = -ESRCH; |
| goto error_path_put; |
| } |
| } |
| |
| err = -ENOMEM; |
| |
| link = kzalloc(sizeof(*link), GFP_KERNEL); |
| uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL); |
| |
| if (!uprobes || !link) |
| goto error_free; |
| |
| for (i = 0; i < cnt; i++) { |
| if (__get_user(uprobes[i].offset, uoffsets + i)) { |
| err = -EFAULT; |
| goto error_free; |
| } |
| if (uprobes[i].offset < 0) { |
| err = -EINVAL; |
| goto error_free; |
| } |
| if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) { |
| err = -EFAULT; |
| goto error_free; |
| } |
| if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) { |
| err = -EFAULT; |
| goto error_free; |
| } |
| |
| uprobes[i].link = link; |
| |
| if (flags & BPF_F_UPROBE_MULTI_RETURN) |
| uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler; |
| else |
| uprobes[i].consumer.handler = uprobe_multi_link_handler; |
| |
| if (pid) |
| uprobes[i].consumer.filter = uprobe_multi_link_filter; |
| } |
| |
| link->cnt = cnt; |
| link->uprobes = uprobes; |
| link->path = path; |
| link->task = task; |
| link->flags = flags; |
| |
| bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI, |
| &bpf_uprobe_multi_link_lops, prog); |
| |
| for (i = 0; i < cnt; i++) { |
| err = uprobe_register_refctr(d_real_inode(link->path.dentry), |
| uprobes[i].offset, |
| uprobes[i].ref_ctr_offset, |
| &uprobes[i].consumer); |
| if (err) { |
| bpf_uprobe_unregister(&path, uprobes, i); |
| goto error_free; |
| } |
| } |
| |
| err = bpf_link_prime(&link->link, &link_primer); |
| if (err) |
| goto error_free; |
| |
| return bpf_link_settle(&link_primer); |
| |
| error_free: |
| kvfree(uprobes); |
| kfree(link); |
| if (task) |
| put_task_struct(task); |
| error_path_put: |
| path_put(&path); |
| return err; |
| } |
| #else /* !CONFIG_UPROBES */ |
| int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) |
| { |
| return -EOPNOTSUPP; |
| } |
| static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx) |
| { |
| return 0; |
| } |
| static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) |
| { |
| return 0; |
| } |
| #endif /* CONFIG_UPROBES */ |