| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Linux Socket Filter - Kernel level socket filtering |
| * |
| * Based on the design of the Berkeley Packet Filter. The new |
| * internal format has been designed by PLUMgrid: |
| * |
| * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com |
| * |
| * Authors: |
| * |
| * Jay Schulist <jschlst@samba.org> |
| * Alexei Starovoitov <ast@plumgrid.com> |
| * Daniel Borkmann <dborkman@redhat.com> |
| * |
| * Andi Kleen - Fix a few bad bugs and races. |
| * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
| */ |
| |
| #include <uapi/linux/btf.h> |
| #include <linux/filter.h> |
| #include <linux/skbuff.h> |
| #include <linux/vmalloc.h> |
| #include <linux/random.h> |
| #include <linux/moduleloader.h> |
| #include <linux/bpf.h> |
| #include <linux/btf.h> |
| #include <linux/frame.h> |
| #include <linux/rbtree_latch.h> |
| #include <linux/kallsyms.h> |
| #include <linux/rcupdate.h> |
| #include <linux/perf_event.h> |
| |
| #include <asm/unaligned.h> |
| |
| /* Registers */ |
| #define BPF_R0 regs[BPF_REG_0] |
| #define BPF_R1 regs[BPF_REG_1] |
| #define BPF_R2 regs[BPF_REG_2] |
| #define BPF_R3 regs[BPF_REG_3] |
| #define BPF_R4 regs[BPF_REG_4] |
| #define BPF_R5 regs[BPF_REG_5] |
| #define BPF_R6 regs[BPF_REG_6] |
| #define BPF_R7 regs[BPF_REG_7] |
| #define BPF_R8 regs[BPF_REG_8] |
| #define BPF_R9 regs[BPF_REG_9] |
| #define BPF_R10 regs[BPF_REG_10] |
| |
| /* Named registers */ |
| #define DST regs[insn->dst_reg] |
| #define SRC regs[insn->src_reg] |
| #define FP regs[BPF_REG_FP] |
| #define AX regs[BPF_REG_AX] |
| #define ARG1 regs[BPF_REG_ARG1] |
| #define CTX regs[BPF_REG_CTX] |
| #define IMM insn->imm |
| |
| /* No hurry in this branch |
| * |
| * Exported for the bpf jit load helper. |
| */ |
| void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) |
| { |
| u8 *ptr = NULL; |
| |
| if (k >= SKF_NET_OFF) |
| ptr = skb_network_header(skb) + k - SKF_NET_OFF; |
| else if (k >= SKF_LL_OFF) |
| ptr = skb_mac_header(skb) + k - SKF_LL_OFF; |
| |
| if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
| return ptr; |
| |
| return NULL; |
| } |
| |
| struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags) |
| { |
| gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
| struct bpf_prog_aux *aux; |
| struct bpf_prog *fp; |
| |
| size = round_up(size, PAGE_SIZE); |
| fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
| if (fp == NULL) |
| return NULL; |
| |
| aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
| if (aux == NULL) { |
| vfree(fp); |
| return NULL; |
| } |
| |
| fp->pages = size / PAGE_SIZE; |
| fp->aux = aux; |
| fp->aux->prog = fp; |
| fp->jit_requested = ebpf_jit_enabled(); |
| |
| INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
| |
| return fp; |
| } |
| |
| struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
| { |
| gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
| struct bpf_prog *prog; |
| int cpu; |
| |
| prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags); |
| if (!prog) |
| return NULL; |
| |
| prog->aux->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags); |
| if (!prog->aux->stats) { |
| kfree(prog->aux); |
| vfree(prog); |
| return NULL; |
| } |
| |
| for_each_possible_cpu(cpu) { |
| struct bpf_prog_stats *pstats; |
| |
| pstats = per_cpu_ptr(prog->aux->stats, cpu); |
| u64_stats_init(&pstats->syncp); |
| } |
| return prog; |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_alloc); |
| |
| int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) |
| { |
| if (!prog->aux->nr_linfo || !prog->jit_requested) |
| return 0; |
| |
| prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo, |
| sizeof(*prog->aux->jited_linfo), |
| GFP_KERNEL | __GFP_NOWARN); |
| if (!prog->aux->jited_linfo) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| void bpf_prog_free_jited_linfo(struct bpf_prog *prog) |
| { |
| kfree(prog->aux->jited_linfo); |
| prog->aux->jited_linfo = NULL; |
| } |
| |
| void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog) |
| { |
| if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0]) |
| bpf_prog_free_jited_linfo(prog); |
| } |
| |
| /* The jit engine is responsible to provide an array |
| * for insn_off to the jited_off mapping (insn_to_jit_off). |
| * |
| * The idx to this array is the insn_off. Hence, the insn_off |
| * here is relative to the prog itself instead of the main prog. |
| * This array has one entry for each xlated bpf insn. |
| * |
| * jited_off is the byte off to the last byte of the jited insn. |
| * |
| * Hence, with |
| * insn_start: |
| * The first bpf insn off of the prog. The insn off |
| * here is relative to the main prog. |
| * e.g. if prog is a subprog, insn_start > 0 |
| * linfo_idx: |
| * The prog's idx to prog->aux->linfo and jited_linfo |
| * |
| * jited_linfo[linfo_idx] = prog->bpf_func |
| * |
| * For i > linfo_idx, |
| * |
| * jited_linfo[i] = prog->bpf_func + |
| * insn_to_jit_off[linfo[i].insn_off - insn_start - 1] |
| */ |
| void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, |
| const u32 *insn_to_jit_off) |
| { |
| u32 linfo_idx, insn_start, insn_end, nr_linfo, i; |
| const struct bpf_line_info *linfo; |
| void **jited_linfo; |
| |
| if (!prog->aux->jited_linfo) |
| /* Userspace did not provide linfo */ |
| return; |
| |
| linfo_idx = prog->aux->linfo_idx; |
| linfo = &prog->aux->linfo[linfo_idx]; |
| insn_start = linfo[0].insn_off; |
| insn_end = insn_start + prog->len; |
| |
| jited_linfo = &prog->aux->jited_linfo[linfo_idx]; |
| jited_linfo[0] = prog->bpf_func; |
| |
| nr_linfo = prog->aux->nr_linfo - linfo_idx; |
| |
| for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++) |
| /* The verifier ensures that linfo[i].insn_off is |
| * strictly increasing |
| */ |
| jited_linfo[i] = prog->bpf_func + |
| insn_to_jit_off[linfo[i].insn_off - insn_start - 1]; |
| } |
| |
| void bpf_prog_free_linfo(struct bpf_prog *prog) |
| { |
| bpf_prog_free_jited_linfo(prog); |
| kvfree(prog->aux->linfo); |
| } |
| |
| struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, |
| gfp_t gfp_extra_flags) |
| { |
| gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
| struct bpf_prog *fp; |
| u32 pages, delta; |
| int ret; |
| |
| BUG_ON(fp_old == NULL); |
| |
| size = round_up(size, PAGE_SIZE); |
| pages = size / PAGE_SIZE; |
| if (pages <= fp_old->pages) |
| return fp_old; |
| |
| delta = pages - fp_old->pages; |
| ret = __bpf_prog_charge(fp_old->aux->user, delta); |
| if (ret) |
| return NULL; |
| |
| fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
| if (fp == NULL) { |
| __bpf_prog_uncharge(fp_old->aux->user, delta); |
| } else { |
| memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
| fp->pages = pages; |
| fp->aux->prog = fp; |
| |
| /* We keep fp->aux from fp_old around in the new |
| * reallocated structure. |
| */ |
| fp_old->aux = NULL; |
| __bpf_prog_free(fp_old); |
| } |
| |
| return fp; |
| } |
| |
| void __bpf_prog_free(struct bpf_prog *fp) |
| { |
| if (fp->aux) { |
| free_percpu(fp->aux->stats); |
| kfree(fp->aux); |
| } |
| vfree(fp); |
| } |
| |
| int bpf_prog_calc_tag(struct bpf_prog *fp) |
| { |
| const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); |
| u32 raw_size = bpf_prog_tag_scratch_size(fp); |
| u32 digest[SHA_DIGEST_WORDS]; |
| u32 ws[SHA_WORKSPACE_WORDS]; |
| u32 i, bsize, psize, blocks; |
| struct bpf_insn *dst; |
| bool was_ld_map; |
| u8 *raw, *todo; |
| __be32 *result; |
| __be64 *bits; |
| |
| raw = vmalloc(raw_size); |
| if (!raw) |
| return -ENOMEM; |
| |
| sha_init(digest); |
| memset(ws, 0, sizeof(ws)); |
| |
| /* We need to take out the map fd for the digest calculation |
| * since they are unstable from user space side. |
| */ |
| dst = (void *)raw; |
| for (i = 0, was_ld_map = false; i < fp->len; i++) { |
| dst[i] = fp->insnsi[i]; |
| if (!was_ld_map && |
| dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && |
| (dst[i].src_reg == BPF_PSEUDO_MAP_FD || |
| dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) { |
| was_ld_map = true; |
| dst[i].imm = 0; |
| } else if (was_ld_map && |
| dst[i].code == 0 && |
| dst[i].dst_reg == 0 && |
| dst[i].src_reg == 0 && |
| dst[i].off == 0) { |
| was_ld_map = false; |
| dst[i].imm = 0; |
| } else { |
| was_ld_map = false; |
| } |
| } |
| |
| psize = bpf_prog_insn_size(fp); |
| memset(&raw[psize], 0, raw_size - psize); |
| raw[psize++] = 0x80; |
| |
| bsize = round_up(psize, SHA_MESSAGE_BYTES); |
| blocks = bsize / SHA_MESSAGE_BYTES; |
| todo = raw; |
| if (bsize - psize >= sizeof(__be64)) { |
| bits = (__be64 *)(todo + bsize - sizeof(__be64)); |
| } else { |
| bits = (__be64 *)(todo + bsize + bits_offset); |
| blocks++; |
| } |
| *bits = cpu_to_be64((psize - 1) << 3); |
| |
| while (blocks--) { |
| sha_transform(digest, todo, ws); |
| todo += SHA_MESSAGE_BYTES; |
| } |
| |
| result = (__force __be32 *)digest; |
| for (i = 0; i < SHA_DIGEST_WORDS; i++) |
| result[i] = cpu_to_be32(digest[i]); |
| memcpy(fp->tag, result, sizeof(fp->tag)); |
| |
| vfree(raw); |
| return 0; |
| } |
| |
| static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old, |
| s32 end_new, s32 curr, const bool probe_pass) |
| { |
| const s64 imm_min = S32_MIN, imm_max = S32_MAX; |
| s32 delta = end_new - end_old; |
| s64 imm = insn->imm; |
| |
| if (curr < pos && curr + imm + 1 >= end_old) |
| imm += delta; |
| else if (curr >= end_new && curr + imm + 1 < end_new) |
| imm -= delta; |
| if (imm < imm_min || imm > imm_max) |
| return -ERANGE; |
| if (!probe_pass) |
| insn->imm = imm; |
| return 0; |
| } |
| |
| static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old, |
| s32 end_new, s32 curr, const bool probe_pass) |
| { |
| const s32 off_min = S16_MIN, off_max = S16_MAX; |
| s32 delta = end_new - end_old; |
| s32 off = insn->off; |
| |
| if (curr < pos && curr + off + 1 >= end_old) |
| off += delta; |
| else if (curr >= end_new && curr + off + 1 < end_new) |
| off -= delta; |
| if (off < off_min || off > off_max) |
| return -ERANGE; |
| if (!probe_pass) |
| insn->off = off; |
| return 0; |
| } |
| |
| static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old, |
| s32 end_new, const bool probe_pass) |
| { |
| u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0); |
| struct bpf_insn *insn = prog->insnsi; |
| int ret = 0; |
| |
| for (i = 0; i < insn_cnt; i++, insn++) { |
| u8 code; |
| |
| /* In the probing pass we still operate on the original, |
| * unpatched image in order to check overflows before we |
| * do any other adjustments. Therefore skip the patchlet. |
| */ |
| if (probe_pass && i == pos) { |
| i = end_new; |
| insn = prog->insnsi + end_old; |
| } |
| code = insn->code; |
| if ((BPF_CLASS(code) != BPF_JMP && |
| BPF_CLASS(code) != BPF_JMP32) || |
| BPF_OP(code) == BPF_EXIT) |
| continue; |
| /* Adjust offset of jmps if we cross patch boundaries. */ |
| if (BPF_OP(code) == BPF_CALL) { |
| if (insn->src_reg != BPF_PSEUDO_CALL) |
| continue; |
| ret = bpf_adj_delta_to_imm(insn, pos, end_old, |
| end_new, i, probe_pass); |
| } else { |
| ret = bpf_adj_delta_to_off(insn, pos, end_old, |
| end_new, i, probe_pass); |
| } |
| if (ret) |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta) |
| { |
| struct bpf_line_info *linfo; |
| u32 i, nr_linfo; |
| |
| nr_linfo = prog->aux->nr_linfo; |
| if (!nr_linfo || !delta) |
| return; |
| |
| linfo = prog->aux->linfo; |
| |
| for (i = 0; i < nr_linfo; i++) |
| if (off < linfo[i].insn_off) |
| break; |
| |
| /* Push all off < linfo[i].insn_off by delta */ |
| for (; i < nr_linfo; i++) |
| linfo[i].insn_off += delta; |
| } |
| |
| struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, |
| const struct bpf_insn *patch, u32 len) |
| { |
| u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; |
| const u32 cnt_max = S16_MAX; |
| struct bpf_prog *prog_adj; |
| int err; |
| |
| /* Since our patchlet doesn't expand the image, we're done. */ |
| if (insn_delta == 0) { |
| memcpy(prog->insnsi + off, patch, sizeof(*patch)); |
| return prog; |
| } |
| |
| insn_adj_cnt = prog->len + insn_delta; |
| |
| /* Reject anything that would potentially let the insn->off |
| * target overflow when we have excessive program expansions. |
| * We need to probe here before we do any reallocation where |
| * we afterwards may not fail anymore. |
| */ |
| if (insn_adj_cnt > cnt_max && |
| (err = bpf_adj_branches(prog, off, off + 1, off + len, true))) |
| return ERR_PTR(err); |
| |
| /* Several new instructions need to be inserted. Make room |
| * for them. Likely, there's no need for a new allocation as |
| * last page could have large enough tailroom. |
| */ |
| prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), |
| GFP_USER); |
| if (!prog_adj) |
| return ERR_PTR(-ENOMEM); |
| |
| prog_adj->len = insn_adj_cnt; |
| |
| /* Patching happens in 3 steps: |
| * |
| * 1) Move over tail of insnsi from next instruction onwards, |
| * so we can patch the single target insn with one or more |
| * new ones (patching is always from 1 to n insns, n > 0). |
| * 2) Inject new instructions at the target location. |
| * 3) Adjust branch offsets if necessary. |
| */ |
| insn_rest = insn_adj_cnt - off - len; |
| |
| memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, |
| sizeof(*patch) * insn_rest); |
| memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); |
| |
| /* We are guaranteed to not fail at this point, otherwise |
| * the ship has sailed to reverse to the original state. An |
| * overflow cannot happen at this point. |
| */ |
| BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false)); |
| |
| bpf_adj_linfo(prog_adj, off, insn_delta); |
| |
| return prog_adj; |
| } |
| |
| int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) |
| { |
| /* Branch offsets can't overflow when program is shrinking, no need |
| * to call bpf_adj_branches(..., true) here |
| */ |
| memmove(prog->insnsi + off, prog->insnsi + off + cnt, |
| sizeof(struct bpf_insn) * (prog->len - off - cnt)); |
| prog->len -= cnt; |
| |
| return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); |
| } |
| |
| void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) |
| { |
| int i; |
| |
| for (i = 0; i < fp->aux->func_cnt; i++) |
| bpf_prog_kallsyms_del(fp->aux->func[i]); |
| } |
| |
| void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) |
| { |
| bpf_prog_kallsyms_del_subprogs(fp); |
| bpf_prog_kallsyms_del(fp); |
| } |
| |
| #ifdef CONFIG_BPF_JIT |
| /* All BPF JIT sysctl knobs here. */ |
| int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); |
| int bpf_jit_harden __read_mostly; |
| int bpf_jit_kallsyms __read_mostly; |
| long bpf_jit_limit __read_mostly; |
| |
| static __always_inline void |
| bpf_get_prog_addr_region(const struct bpf_prog *prog, |
| unsigned long *symbol_start, |
| unsigned long *symbol_end) |
| { |
| const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); |
| unsigned long addr = (unsigned long)hdr; |
| |
| WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); |
| |
| *symbol_start = addr; |
| *symbol_end = addr + hdr->pages * PAGE_SIZE; |
| } |
| |
| void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) |
| { |
| const char *end = sym + KSYM_NAME_LEN; |
| const struct btf_type *type; |
| const char *func_name; |
| |
| BUILD_BUG_ON(sizeof("bpf_prog_") + |
| sizeof(prog->tag) * 2 + |
| /* name has been null terminated. |
| * We should need +1 for the '_' preceding |
| * the name. However, the null character |
| * is double counted between the name and the |
| * sizeof("bpf_prog_") above, so we omit |
| * the +1 here. |
| */ |
| sizeof(prog->aux->name) > KSYM_NAME_LEN); |
| |
| sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); |
| sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); |
| |
| /* prog->aux->name will be ignored if full btf name is available */ |
| if (prog->aux->func_info_cnt) { |
| type = btf_type_by_id(prog->aux->btf, |
| prog->aux->func_info[prog->aux->func_idx].type_id); |
| func_name = btf_name_by_offset(prog->aux->btf, type->name_off); |
| snprintf(sym, (size_t)(end - sym), "_%s", func_name); |
| return; |
| } |
| |
| if (prog->aux->name[0]) |
| snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); |
| else |
| *sym = 0; |
| } |
| |
| static __always_inline unsigned long |
| bpf_get_prog_addr_start(struct latch_tree_node *n) |
| { |
| unsigned long symbol_start, symbol_end; |
| const struct bpf_prog_aux *aux; |
| |
| aux = container_of(n, struct bpf_prog_aux, ksym_tnode); |
| bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); |
| |
| return symbol_start; |
| } |
| |
| static __always_inline bool bpf_tree_less(struct latch_tree_node *a, |
| struct latch_tree_node *b) |
| { |
| return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); |
| } |
| |
| static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) |
| { |
| unsigned long val = (unsigned long)key; |
| unsigned long symbol_start, symbol_end; |
| const struct bpf_prog_aux *aux; |
| |
| aux = container_of(n, struct bpf_prog_aux, ksym_tnode); |
| bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); |
| |
| if (val < symbol_start) |
| return -1; |
| if (val >= symbol_end) |
| return 1; |
| |
| return 0; |
| } |
| |
| static const struct latch_tree_ops bpf_tree_ops = { |
| .less = bpf_tree_less, |
| .comp = bpf_tree_comp, |
| }; |
| |
| static DEFINE_SPINLOCK(bpf_lock); |
| static LIST_HEAD(bpf_kallsyms); |
| static struct latch_tree_root bpf_tree __cacheline_aligned; |
| |
| static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) |
| { |
| WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); |
| list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); |
| latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); |
| } |
| |
| static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) |
| { |
| if (list_empty(&aux->ksym_lnode)) |
| return; |
| |
| latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); |
| list_del_rcu(&aux->ksym_lnode); |
| } |
| |
| static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) |
| { |
| return fp->jited && !bpf_prog_was_classic(fp); |
| } |
| |
| static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) |
| { |
| return list_empty(&fp->aux->ksym_lnode) || |
| fp->aux->ksym_lnode.prev == LIST_POISON2; |
| } |
| |
| void bpf_prog_kallsyms_add(struct bpf_prog *fp) |
| { |
| if (!bpf_prog_kallsyms_candidate(fp) || |
| !capable(CAP_SYS_ADMIN)) |
| return; |
| |
| spin_lock_bh(&bpf_lock); |
| bpf_prog_ksym_node_add(fp->aux); |
| spin_unlock_bh(&bpf_lock); |
| } |
| |
| void bpf_prog_kallsyms_del(struct bpf_prog *fp) |
| { |
| if (!bpf_prog_kallsyms_candidate(fp)) |
| return; |
| |
| spin_lock_bh(&bpf_lock); |
| bpf_prog_ksym_node_del(fp->aux); |
| spin_unlock_bh(&bpf_lock); |
| } |
| |
| static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) |
| { |
| struct latch_tree_node *n; |
| |
| if (!bpf_jit_kallsyms_enabled()) |
| return NULL; |
| |
| n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); |
| return n ? |
| container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : |
| NULL; |
| } |
| |
| const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, |
| unsigned long *off, char *sym) |
| { |
| unsigned long symbol_start, symbol_end; |
| struct bpf_prog *prog; |
| char *ret = NULL; |
| |
| rcu_read_lock(); |
| prog = bpf_prog_kallsyms_find(addr); |
| if (prog) { |
| bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); |
| bpf_get_prog_name(prog, sym); |
| |
| ret = sym; |
| if (size) |
| *size = symbol_end - symbol_start; |
| if (off) |
| *off = addr - symbol_start; |
| } |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| bool is_bpf_text_address(unsigned long addr) |
| { |
| bool ret; |
| |
| rcu_read_lock(); |
| ret = bpf_prog_kallsyms_find(addr) != NULL; |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, |
| char *sym) |
| { |
| struct bpf_prog_aux *aux; |
| unsigned int it = 0; |
| int ret = -ERANGE; |
| |
| if (!bpf_jit_kallsyms_enabled()) |
| return ret; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { |
| if (it++ != symnum) |
| continue; |
| |
| bpf_get_prog_name(aux->prog, sym); |
| |
| *value = (unsigned long)aux->prog->bpf_func; |
| *type = BPF_SYM_ELF_TYPE; |
| |
| ret = 0; |
| break; |
| } |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| static atomic_long_t bpf_jit_current; |
| |
| /* Can be overridden by an arch's JIT compiler if it has a custom, |
| * dedicated BPF backend memory area, or if neither of the two |
| * below apply. |
| */ |
| u64 __weak bpf_jit_alloc_exec_limit(void) |
| { |
| #if defined(MODULES_VADDR) |
| return MODULES_END - MODULES_VADDR; |
| #else |
| return VMALLOC_END - VMALLOC_START; |
| #endif |
| } |
| |
| static int __init bpf_jit_charge_init(void) |
| { |
| /* Only used as heuristic here to derive limit. */ |
| bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, |
| PAGE_SIZE), LONG_MAX); |
| return 0; |
| } |
| pure_initcall(bpf_jit_charge_init); |
| |
| static int bpf_jit_charge_modmem(u32 pages) |
| { |
| if (atomic_long_add_return(pages, &bpf_jit_current) > |
| (bpf_jit_limit >> PAGE_SHIFT)) { |
| if (!capable(CAP_SYS_ADMIN)) { |
| atomic_long_sub(pages, &bpf_jit_current); |
| return -EPERM; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void bpf_jit_uncharge_modmem(u32 pages) |
| { |
| atomic_long_sub(pages, &bpf_jit_current); |
| } |
| |
| void *__weak bpf_jit_alloc_exec(unsigned long size) |
| { |
| return module_alloc(size); |
| } |
| |
| void __weak bpf_jit_free_exec(void *addr) |
| { |
| module_memfree(addr); |
| } |
| |
| struct bpf_binary_header * |
| bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, |
| unsigned int alignment, |
| bpf_jit_fill_hole_t bpf_fill_ill_insns) |
| { |
| struct bpf_binary_header *hdr; |
| u32 size, hole, start, pages; |
| |
| /* Most of BPF filters are really small, but if some of them |
| * fill a page, allow at least 128 extra bytes to insert a |
| * random section of illegal instructions. |
| */ |
| size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); |
| pages = size / PAGE_SIZE; |
| |
| if (bpf_jit_charge_modmem(pages)) |
| return NULL; |
| hdr = bpf_jit_alloc_exec(size); |
| if (!hdr) { |
| bpf_jit_uncharge_modmem(pages); |
| return NULL; |
| } |
| |
| /* Fill space with illegal/arch-dep instructions. */ |
| bpf_fill_ill_insns(hdr, size); |
| |
| hdr->pages = pages; |
| hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), |
| PAGE_SIZE - sizeof(*hdr)); |
| start = (get_random_int() % hole) & ~(alignment - 1); |
| |
| /* Leave a random number of instructions before BPF code. */ |
| *image_ptr = &hdr->image[start]; |
| |
| return hdr; |
| } |
| |
| void bpf_jit_binary_free(struct bpf_binary_header *hdr) |
| { |
| u32 pages = hdr->pages; |
| |
| bpf_jit_free_exec(hdr); |
| bpf_jit_uncharge_modmem(pages); |
| } |
| |
| /* This symbol is only overridden by archs that have different |
| * requirements than the usual eBPF JITs, f.e. when they only |
| * implement cBPF JIT, do not set images read-only, etc. |
| */ |
| void __weak bpf_jit_free(struct bpf_prog *fp) |
| { |
| if (fp->jited) { |
| struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); |
| |
| bpf_jit_binary_free(hdr); |
| |
| WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); |
| } |
| |
| bpf_prog_unlock_free(fp); |
| } |
| |
| int bpf_jit_get_func_addr(const struct bpf_prog *prog, |
| const struct bpf_insn *insn, bool extra_pass, |
| u64 *func_addr, bool *func_addr_fixed) |
| { |
| s16 off = insn->off; |
| s32 imm = insn->imm; |
| u8 *addr; |
| |
| *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL; |
| if (!*func_addr_fixed) { |
| /* Place-holder address till the last pass has collected |
| * all addresses for JITed subprograms in which case we |
| * can pick them up from prog->aux. |
| */ |
| if (!extra_pass) |
| addr = NULL; |
| else if (prog->aux->func && |
| off >= 0 && off < prog->aux->func_cnt) |
| addr = (u8 *)prog->aux->func[off]->bpf_func; |
| else |
| return -EINVAL; |
| } else { |
| /* Address of a BPF helper call. Since part of the core |
| * kernel, it's always at a fixed location. __bpf_call_base |
| * and the helper with imm relative to it are both in core |
| * kernel. |
| */ |
| addr = (u8 *)__bpf_call_base + imm; |
| } |
| |
| *func_addr = (unsigned long)addr; |
| return 0; |
| } |
| |
| static int bpf_jit_blind_insn(const struct bpf_insn *from, |
| const struct bpf_insn *aux, |
| struct bpf_insn *to_buff) |
| { |
| struct bpf_insn *to = to_buff; |
| u32 imm_rnd = get_random_int(); |
| s16 off; |
| |
| BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); |
| BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); |
| |
| /* Constraints on AX register: |
| * |
| * AX register is inaccessible from user space. It is mapped in |
| * all JITs, and used here for constant blinding rewrites. It is |
| * typically "stateless" meaning its contents are only valid within |
| * the executed instruction, but not across several instructions. |
| * There are a few exceptions however which are further detailed |
| * below. |
| * |
| * Constant blinding is only used by JITs, not in the interpreter. |
| * The interpreter uses AX in some occasions as a local temporary |
| * register e.g. in DIV or MOD instructions. |
| * |
| * In restricted circumstances, the verifier can also use the AX |
| * register for rewrites as long as they do not interfere with |
| * the above cases! |
| */ |
| if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) |
| goto out; |
| |
| if (from->imm == 0 && |
| (from->code == (BPF_ALU | BPF_MOV | BPF_K) || |
| from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { |
| *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); |
| goto out; |
| } |
| |
| switch (from->code) { |
| case BPF_ALU | BPF_ADD | BPF_K: |
| case BPF_ALU | BPF_SUB | BPF_K: |
| case BPF_ALU | BPF_AND | BPF_K: |
| case BPF_ALU | BPF_OR | BPF_K: |
| case BPF_ALU | BPF_XOR | BPF_K: |
| case BPF_ALU | BPF_MUL | BPF_K: |
| case BPF_ALU | BPF_MOV | BPF_K: |
| case BPF_ALU | BPF_DIV | BPF_K: |
| case BPF_ALU | BPF_MOD | BPF_K: |
| *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); |
| *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); |
| break; |
| |
| case BPF_ALU64 | BPF_ADD | BPF_K: |
| case BPF_ALU64 | BPF_SUB | BPF_K: |
| case BPF_ALU64 | BPF_AND | BPF_K: |
| case BPF_ALU64 | BPF_OR | BPF_K: |
| case BPF_ALU64 | BPF_XOR | BPF_K: |
| case BPF_ALU64 | BPF_MUL | BPF_K: |
| case BPF_ALU64 | BPF_MOV | BPF_K: |
| case BPF_ALU64 | BPF_DIV | BPF_K: |
| case BPF_ALU64 | BPF_MOD | BPF_K: |
| *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); |
| *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); |
| break; |
| |
| case BPF_JMP | BPF_JEQ | BPF_K: |
| case BPF_JMP | BPF_JNE | BPF_K: |
| case BPF_JMP | BPF_JGT | BPF_K: |
| case BPF_JMP | BPF_JLT | BPF_K: |
| case BPF_JMP | BPF_JGE | BPF_K: |
| case BPF_JMP | BPF_JLE | BPF_K: |
| case BPF_JMP | BPF_JSGT | BPF_K: |
| case BPF_JMP | BPF_JSLT | BPF_K: |
| case BPF_JMP | BPF_JSGE | BPF_K: |
| case BPF_JMP | BPF_JSLE | BPF_K: |
| case BPF_JMP | BPF_JSET | BPF_K: |
| /* Accommodate for extra offset in case of a backjump. */ |
| off = from->off; |
| if (off < 0) |
| off -= 2; |
| *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); |
| *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); |
| break; |
| |
| case BPF_JMP32 | BPF_JEQ | BPF_K: |
| case BPF_JMP32 | BPF_JNE | BPF_K: |
| case BPF_JMP32 | BPF_JGT | BPF_K: |
| case BPF_JMP32 | BPF_JLT | BPF_K: |
| case BPF_JMP32 | BPF_JGE | BPF_K: |
| case BPF_JMP32 | BPF_JLE | BPF_K: |
| case BPF_JMP32 | BPF_JSGT | BPF_K: |
| case BPF_JMP32 | BPF_JSLT | BPF_K: |
| case BPF_JMP32 | BPF_JSGE | BPF_K: |
| case BPF_JMP32 | BPF_JSLE | BPF_K: |
| case BPF_JMP32 | BPF_JSET | BPF_K: |
| /* Accommodate for extra offset in case of a backjump. */ |
| off = from->off; |
| if (off < 0) |
| off -= 2; |
| *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); |
| *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX, |
| off); |
| break; |
| |
| case BPF_LD | BPF_IMM | BPF_DW: |
| *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); |
| *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); |
| *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); |
| break; |
| case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ |
| *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); |
| *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); |
| break; |
| |
| case BPF_ST | BPF_MEM | BPF_DW: |
| case BPF_ST | BPF_MEM | BPF_W: |
| case BPF_ST | BPF_MEM | BPF_H: |
| case BPF_ST | BPF_MEM | BPF_B: |
| *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); |
| *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); |
| *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); |
| break; |
| } |
| out: |
| return to - to_buff; |
| } |
| |
| static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, |
| gfp_t gfp_extra_flags) |
| { |
| gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
| struct bpf_prog *fp; |
| |
| fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); |
| if (fp != NULL) { |
| /* aux->prog still points to the fp_other one, so |
| * when promoting the clone to the real program, |
| * this still needs to be adapted. |
| */ |
| memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); |
| } |
| |
| return fp; |
| } |
| |
| static void bpf_prog_clone_free(struct bpf_prog *fp) |
| { |
| /* aux was stolen by the other clone, so we cannot free |
| * it from this path! It will be freed eventually by the |
| * other program on release. |
| * |
| * At this point, we don't need a deferred release since |
| * clone is guaranteed to not be locked. |
| */ |
| fp->aux = NULL; |
| __bpf_prog_free(fp); |
| } |
| |
| void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) |
| { |
| /* We have to repoint aux->prog to self, as we don't |
| * know whether fp here is the clone or the original. |
| */ |
| fp->aux->prog = fp; |
| bpf_prog_clone_free(fp_other); |
| } |
| |
| struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) |
| { |
| struct bpf_insn insn_buff[16], aux[2]; |
| struct bpf_prog *clone, *tmp; |
| int insn_delta, insn_cnt; |
| struct bpf_insn *insn; |
| int i, rewritten; |
| |
| if (!bpf_jit_blinding_enabled(prog) || prog->blinded) |
| return prog; |
| |
| clone = bpf_prog_clone_create(prog, GFP_USER); |
| if (!clone) |
| return ERR_PTR(-ENOMEM); |
| |
| insn_cnt = clone->len; |
| insn = clone->insnsi; |
| |
| for (i = 0; i < insn_cnt; i++, insn++) { |
| /* We temporarily need to hold the original ld64 insn |
| * so that we can still access the first part in the |
| * second blinding run. |
| */ |
| if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && |
| insn[1].code == 0) |
| memcpy(aux, insn, sizeof(aux)); |
| |
| rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); |
| if (!rewritten) |
| continue; |
| |
| tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); |
| if (IS_ERR(tmp)) { |
| /* Patching may have repointed aux->prog during |
| * realloc from the original one, so we need to |
| * fix it up here on error. |
| */ |
| bpf_jit_prog_release_other(prog, clone); |
| return tmp; |
| } |
| |
| clone = tmp; |
| insn_delta = rewritten - 1; |
| |
| /* Walk new program and skip insns we just inserted. */ |
| insn = clone->insnsi + i + insn_delta; |
| insn_cnt += insn_delta; |
| i += insn_delta; |
| } |
| |
| clone->blinded = 1; |
| return clone; |
| } |
| #endif /* CONFIG_BPF_JIT */ |
| |
| /* Base function for offset calculation. Needs to go into .text section, |
| * therefore keeping it non-static as well; will also be used by JITs |
| * anyway later on, so do not let the compiler omit it. This also needs |
| * to go into kallsyms for correlation from e.g. bpftool, so naming |
| * must not change. |
| */ |
| noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(__bpf_call_base); |
| |
| /* All UAPI available opcodes. */ |
| #define BPF_INSN_MAP(INSN_2, INSN_3) \ |
| /* 32 bit ALU operations. */ \ |
| /* Register based. */ \ |
| INSN_3(ALU, ADD, X), \ |
| INSN_3(ALU, SUB, X), \ |
| INSN_3(ALU, AND, X), \ |
| INSN_3(ALU, OR, X), \ |
| INSN_3(ALU, LSH, X), \ |
| INSN_3(ALU, RSH, X), \ |
| INSN_3(ALU, XOR, X), \ |
| INSN_3(ALU, MUL, X), \ |
| INSN_3(ALU, MOV, X), \ |
| INSN_3(ALU, ARSH, X), \ |
| INSN_3(ALU, DIV, X), \ |
| INSN_3(ALU, MOD, X), \ |
| INSN_2(ALU, NEG), \ |
| INSN_3(ALU, END, TO_BE), \ |
| INSN_3(ALU, END, TO_LE), \ |
| /* Immediate based. */ \ |
| INSN_3(ALU, ADD, K), \ |
| INSN_3(ALU, SUB, K), \ |
| INSN_3(ALU, AND, K), \ |
| INSN_3(ALU, OR, K), \ |
| INSN_3(ALU, LSH, K), \ |
| INSN_3(ALU, RSH, K), \ |
| INSN_3(ALU, XOR, K), \ |
| INSN_3(ALU, MUL, K), \ |
| INSN_3(ALU, MOV, K), \ |
| INSN_3(ALU, ARSH, K), \ |
| INSN_3(ALU, DIV, K), \ |
| INSN_3(ALU, MOD, K), \ |
| /* 64 bit ALU operations. */ \ |
| /* Register based. */ \ |
| INSN_3(ALU64, ADD, X), \ |
| INSN_3(ALU64, SUB, X), \ |
| INSN_3(ALU64, AND, X), \ |
| INSN_3(ALU64, OR, X), \ |
| INSN_3(ALU64, LSH, X), \ |
| INSN_3(ALU64, RSH, X), \ |
| INSN_3(ALU64, XOR, X), \ |
| INSN_3(ALU64, MUL, X), \ |
| INSN_3(ALU64, MOV, X), \ |
| INSN_3(ALU64, ARSH, X), \ |
| INSN_3(ALU64, DIV, X), \ |
| INSN_3(ALU64, MOD, X), \ |
| INSN_2(ALU64, NEG), \ |
| /* Immediate based. */ \ |
| INSN_3(ALU64, ADD, K), \ |
| INSN_3(ALU64, SUB, K), \ |
| INSN_3(ALU64, AND, K), \ |
| INSN_3(ALU64, OR, K), \ |
| INSN_3(ALU64, LSH, K), \ |
| INSN_3(ALU64, RSH, K), \ |
| INSN_3(ALU64, XOR, K), \ |
| INSN_3(ALU64, MUL, K), \ |
| INSN_3(ALU64, MOV, K), \ |
| INSN_3(ALU64, ARSH, K), \ |
| INSN_3(ALU64, DIV, K), \ |
| INSN_3(ALU64, MOD, K), \ |
| /* Call instruction. */ \ |
| INSN_2(JMP, CALL), \ |
| /* Exit instruction. */ \ |
| INSN_2(JMP, EXIT), \ |
| /* 32-bit Jump instructions. */ \ |
| /* Register based. */ \ |
| INSN_3(JMP32, JEQ, X), \ |
| INSN_3(JMP32, JNE, X), \ |
| INSN_3(JMP32, JGT, X), \ |
| INSN_3(JMP32, JLT, X), \ |
| INSN_3(JMP32, JGE, X), \ |
| INSN_3(JMP32, JLE, X), \ |
| INSN_3(JMP32, JSGT, X), \ |
| INSN_3(JMP32, JSLT, X), \ |
| INSN_3(JMP32, JSGE, X), \ |
| INSN_3(JMP32, JSLE, X), \ |
| INSN_3(JMP32, JSET, X), \ |
| /* Immediate based. */ \ |
| INSN_3(JMP32, JEQ, K), \ |
| INSN_3(JMP32, JNE, K), \ |
| INSN_3(JMP32, JGT, K), \ |
| INSN_3(JMP32, JLT, K), \ |
| INSN_3(JMP32, JGE, K), \ |
| INSN_3(JMP32, JLE, K), \ |
| INSN_3(JMP32, JSGT, K), \ |
| INSN_3(JMP32, JSLT, K), \ |
| INSN_3(JMP32, JSGE, K), \ |
| INSN_3(JMP32, JSLE, K), \ |
| INSN_3(JMP32, JSET, K), \ |
| /* Jump instructions. */ \ |
| /* Register based. */ \ |
| INSN_3(JMP, JEQ, X), \ |
| INSN_3(JMP, JNE, X), \ |
| INSN_3(JMP, JGT, X), \ |
| INSN_3(JMP, JLT, X), \ |
| INSN_3(JMP, JGE, X), \ |
| INSN_3(JMP, JLE, X), \ |
| INSN_3(JMP, JSGT, X), \ |
| INSN_3(JMP, JSLT, X), \ |
| INSN_3(JMP, JSGE, X), \ |
| INSN_3(JMP, JSLE, X), \ |
| INSN_3(JMP, JSET, X), \ |
| /* Immediate based. */ \ |
| INSN_3(JMP, JEQ, K), \ |
| INSN_3(JMP, JNE, K), \ |
| INSN_3(JMP, JGT, K), \ |
| INSN_3(JMP, JLT, K), \ |
| INSN_3(JMP, JGE, K), \ |
| INSN_3(JMP, JLE, K), \ |
| INSN_3(JMP, JSGT, K), \ |
| INSN_3(JMP, JSLT, K), \ |
| INSN_3(JMP, JSGE, K), \ |
| INSN_3(JMP, JSLE, K), \ |
| INSN_3(JMP, JSET, K), \ |
| INSN_2(JMP, JA), \ |
| /* Store instructions. */ \ |
| /* Register based. */ \ |
| INSN_3(STX, MEM, B), \ |
| INSN_3(STX, MEM, H), \ |
| INSN_3(STX, MEM, W), \ |
| INSN_3(STX, MEM, DW), \ |
| INSN_3(STX, XADD, W), \ |
| INSN_3(STX, XADD, DW), \ |
| /* Immediate based. */ \ |
| INSN_3(ST, MEM, B), \ |
| INSN_3(ST, MEM, H), \ |
| INSN_3(ST, MEM, W), \ |
| INSN_3(ST, MEM, DW), \ |
| /* Load instructions. */ \ |
| /* Register based. */ \ |
| INSN_3(LDX, MEM, B), \ |
| INSN_3(LDX, MEM, H), \ |
| INSN_3(LDX, MEM, W), \ |
| INSN_3(LDX, MEM, DW), \ |
| /* Immediate based. */ \ |
| INSN_3(LD, IMM, DW) |
| |
| bool bpf_opcode_in_insntable(u8 code) |
| { |
| #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true |
| #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true |
| static const bool public_insntable[256] = { |
| [0 ... 255] = false, |
| /* Now overwrite non-defaults ... */ |
| BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), |
| /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */ |
| [BPF_LD | BPF_ABS | BPF_B] = true, |
| [BPF_LD | BPF_ABS | BPF_H] = true, |
| [BPF_LD | BPF_ABS | BPF_W] = true, |
| [BPF_LD | BPF_IND | BPF_B] = true, |
| [BPF_LD | BPF_IND | BPF_H] = true, |
| [BPF_LD | BPF_IND | BPF_W] = true, |
| }; |
| #undef BPF_INSN_3_TBL |
| #undef BPF_INSN_2_TBL |
| return public_insntable[code]; |
| } |
| |
| #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
| /** |
| * __bpf_prog_run - run eBPF program on a given context |
| * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers |
| * @insn: is the array of eBPF instructions |
| * @stack: is the eBPF storage stack |
| * |
| * Decode and execute eBPF instructions. |
| */ |
| static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) |
| { |
| #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y |
| #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z |
| static const void *jumptable[256] = { |
| [0 ... 255] = &&default_label, |
| /* Now overwrite non-defaults ... */ |
| BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), |
| /* Non-UAPI available opcodes. */ |
| [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, |
| [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
| }; |
| #undef BPF_INSN_3_LBL |
| #undef BPF_INSN_2_LBL |
| u32 tail_call_cnt = 0; |
| |
| #define CONT ({ insn++; goto select_insn; }) |
| #define CONT_JMP ({ insn++; goto select_insn; }) |
| |
| select_insn: |
| goto *jumptable[insn->code]; |
| |
| /* ALU */ |
| #define ALU(OPCODE, OP) \ |
| ALU64_##OPCODE##_X: \ |
| DST = DST OP SRC; \ |
| CONT; \ |
| ALU_##OPCODE##_X: \ |
| DST = (u32) DST OP (u32) SRC; \ |
| CONT; \ |
| ALU64_##OPCODE##_K: \ |
| DST = DST OP IMM; \ |
| CONT; \ |
| ALU_##OPCODE##_K: \ |
| DST = (u32) DST OP (u32) IMM; \ |
| CONT; |
| |
| ALU(ADD, +) |
| ALU(SUB, -) |
| ALU(AND, &) |
| ALU(OR, |) |
| ALU(LSH, <<) |
| ALU(RSH, >>) |
| ALU(XOR, ^) |
| ALU(MUL, *) |
| #undef ALU |
| ALU_NEG: |
| DST = (u32) -DST; |
| CONT; |
| ALU64_NEG: |
| DST = -DST; |
| CONT; |
| ALU_MOV_X: |
| DST = (u32) SRC; |
| CONT; |
| ALU_MOV_K: |
| DST = (u32) IMM; |
| CONT; |
| ALU64_MOV_X: |
| DST = SRC; |
| CONT; |
| ALU64_MOV_K: |
| DST = IMM; |
| CONT; |
| LD_IMM_DW: |
| DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; |
| insn++; |
| CONT; |
| ALU_ARSH_X: |
| DST = (u64) (u32) ((*(s32 *) &DST) >> SRC); |
| CONT; |
| ALU_ARSH_K: |
| DST = (u64) (u32) ((*(s32 *) &DST) >> IMM); |
| CONT; |
| ALU64_ARSH_X: |
| (*(s64 *) &DST) >>= SRC; |
| CONT; |
| ALU64_ARSH_K: |
| (*(s64 *) &DST) >>= IMM; |
| CONT; |
| ALU64_MOD_X: |
| div64_u64_rem(DST, SRC, &AX); |
| DST = AX; |
| CONT; |
| ALU_MOD_X: |
| AX = (u32) DST; |
| DST = do_div(AX, (u32) SRC); |
| CONT; |
| ALU64_MOD_K: |
| div64_u64_rem(DST, IMM, &AX); |
| DST = AX; |
| CONT; |
| ALU_MOD_K: |
| AX = (u32) DST; |
| DST = do_div(AX, (u32) IMM); |
| CONT; |
| ALU64_DIV_X: |
| DST = div64_u64(DST, SRC); |
| CONT; |
| ALU_DIV_X: |
| AX = (u32) DST; |
| do_div(AX, (u32) SRC); |
| DST = (u32) AX; |
| CONT; |
| ALU64_DIV_K: |
| DST = div64_u64(DST, IMM); |
| CONT; |
| ALU_DIV_K: |
| AX = (u32) DST; |
| do_div(AX, (u32) IMM); |
| DST = (u32) AX; |
| CONT; |
| ALU_END_TO_BE: |
| switch (IMM) { |
| case 16: |
| DST = (__force u16) cpu_to_be16(DST); |
| break; |
| case 32: |
| DST = (__force u32) cpu_to_be32(DST); |
| break; |
| case 64: |
| DST = (__force u64) cpu_to_be64(DST); |
| break; |
| } |
| CONT; |
| ALU_END_TO_LE: |
| switch (IMM) { |
| case 16: |
| DST = (__force u16) cpu_to_le16(DST); |
| break; |
| case 32: |
| DST = (__force u32) cpu_to_le32(DST); |
| break; |
| case 64: |
| DST = (__force u64) cpu_to_le64(DST); |
| break; |
| } |
| CONT; |
| |
| /* CALL */ |
| JMP_CALL: |
| /* Function call scratches BPF_R1-BPF_R5 registers, |
| * preserves BPF_R6-BPF_R9, and stores return value |
| * into BPF_R0. |
| */ |
| BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, |
| BPF_R4, BPF_R5); |
| CONT; |
| |
| JMP_CALL_ARGS: |
| BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, |
| BPF_R3, BPF_R4, |
| BPF_R5, |
| insn + insn->off + 1); |
| CONT; |
| |
| JMP_TAIL_CALL: { |
| struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; |
| struct bpf_array *array = container_of(map, struct bpf_array, map); |
| struct bpf_prog *prog; |
| u32 index = BPF_R3; |
| |
| if (unlikely(index >= array->map.max_entries)) |
| goto out; |
| if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
| goto out; |
| |
| tail_call_cnt++; |
| |
| prog = READ_ONCE(array->ptrs[index]); |
| if (!prog) |
| goto out; |
| |
| /* ARG1 at this point is guaranteed to point to CTX from |
| * the verifier side due to the fact that the tail call is |
| * handeled like a helper, that is, bpf_tail_call_proto, |
| * where arg1_type is ARG_PTR_TO_CTX. |
| */ |
| insn = prog->insnsi; |
| goto select_insn; |
| out: |
| CONT; |
| } |
| JMP_JA: |
| insn += insn->off; |
| CONT; |
| JMP_EXIT: |
| return BPF_R0; |
| /* JMP */ |
| #define COND_JMP(SIGN, OPCODE, CMP_OP) \ |
| JMP_##OPCODE##_X: \ |
| if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \ |
| insn += insn->off; \ |
| CONT_JMP; \ |
| } \ |
| CONT; \ |
| JMP32_##OPCODE##_X: \ |
| if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \ |
| insn += insn->off; \ |
| CONT_JMP; \ |
| } \ |
| CONT; \ |
| JMP_##OPCODE##_K: \ |
| if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \ |
| insn += insn->off; \ |
| CONT_JMP; \ |
| } \ |
| CONT; \ |
| JMP32_##OPCODE##_K: \ |
| if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \ |
| insn += insn->off; \ |
| CONT_JMP; \ |
| } \ |
| CONT; |
| COND_JMP(u, JEQ, ==) |
| COND_JMP(u, JNE, !=) |
| COND_JMP(u, JGT, >) |
| COND_JMP(u, JLT, <) |
| COND_JMP(u, JGE, >=) |
| COND_JMP(u, JLE, <=) |
| COND_JMP(u, JSET, &) |
| COND_JMP(s, JSGT, >) |
| COND_JMP(s, JSLT, <) |
| COND_JMP(s, JSGE, >=) |
| COND_JMP(s, JSLE, <=) |
| #undef COND_JMP |
| /* STX and ST and LDX*/ |
| #define LDST(SIZEOP, SIZE) \ |
| STX_MEM_##SIZEOP: \ |
| *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ |
| CONT; \ |
| ST_MEM_##SIZEOP: \ |
| *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ |
| CONT; \ |
| LDX_MEM_##SIZEOP: \ |
| DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ |
| CONT; |
| |
| LDST(B, u8) |
| LDST(H, u16) |
| LDST(W, u32) |
| LDST(DW, u64) |
| #undef LDST |
| STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ |
| atomic_add((u32) SRC, (atomic_t *)(unsigned long) |
| (DST + insn->off)); |
| CONT; |
| STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ |
| atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) |
| (DST + insn->off)); |
| CONT; |
| |
| default_label: |
| /* If we ever reach this, we have a bug somewhere. Die hard here |
| * instead of just returning 0; we could be somewhere in a subprog, |
| * so execution could continue otherwise which we do /not/ want. |
| * |
| * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). |
| */ |
| pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code); |
| BUG_ON(1); |
| return 0; |
| } |
| STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ |
| |
| #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
| #define DEFINE_BPF_PROG_RUN(stack_size) \ |
| static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ |
| { \ |
| u64 stack[stack_size / sizeof(u64)]; \ |
| u64 regs[MAX_BPF_EXT_REG]; \ |
| \ |
| FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ |
| ARG1 = (u64) (unsigned long) ctx; \ |
| return ___bpf_prog_run(regs, insn, stack); \ |
| } |
| |
| #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size |
| #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ |
| static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ |
| const struct bpf_insn *insn) \ |
| { \ |
| u64 stack[stack_size / sizeof(u64)]; \ |
| u64 regs[MAX_BPF_EXT_REG]; \ |
| \ |
| FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ |
| BPF_R1 = r1; \ |
| BPF_R2 = r2; \ |
| BPF_R3 = r3; \ |
| BPF_R4 = r4; \ |
| BPF_R5 = r5; \ |
| return ___bpf_prog_run(regs, insn, stack); \ |
| } |
| |
| #define EVAL1(FN, X) FN(X) |
| #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) |
| #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) |
| #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) |
| #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) |
| #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) |
| |
| EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); |
| EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); |
| EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); |
| |
| EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); |
| EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); |
| EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); |
| |
| #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), |
| |
| static unsigned int (*interpreters[])(const void *ctx, |
| const struct bpf_insn *insn) = { |
| EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) |
| EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) |
| EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) |
| }; |
| #undef PROG_NAME_LIST |
| #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), |
| static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, |
| const struct bpf_insn *insn) = { |
| EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) |
| EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) |
| EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) |
| }; |
| #undef PROG_NAME_LIST |
| |
| void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) |
| { |
| stack_depth = max_t(u32, stack_depth, 1); |
| insn->off = (s16) insn->imm; |
| insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - |
| __bpf_call_base_args; |
| insn->code = BPF_JMP | BPF_CALL_ARGS; |
| } |
| |
| #else |
| static unsigned int __bpf_prog_ret0_warn(const void *ctx, |
| const struct bpf_insn *insn) |
| { |
| /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON |
| * is not working properly, so warn about it! |
| */ |
| WARN_ON_ONCE(1); |
| return 0; |
| } |
| #endif |
| |
| bool bpf_prog_array_compatible(struct bpf_array *array, |
| const struct bpf_prog *fp) |
| { |
| if (fp->kprobe_override) |
| return false; |
| |
| if (!array->owner_prog_type) { |
| /* There's no owner yet where we could check for |
| * compatibility. |
| */ |
| array->owner_prog_type = fp->type; |
| array->owner_jited = fp->jited; |
| |
| return true; |
| } |
| |
| return array->owner_prog_type == fp->type && |
| array->owner_jited == fp->jited; |
| } |
| |
| static int bpf_check_tail_call(const struct bpf_prog *fp) |
| { |
| struct bpf_prog_aux *aux = fp->aux; |
| int i; |
| |
| for (i = 0; i < aux->used_map_cnt; i++) { |
| struct bpf_map *map = aux->used_maps[i]; |
| struct bpf_array *array; |
| |
| if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
| continue; |
| |
| array = container_of(map, struct bpf_array, map); |
| if (!bpf_prog_array_compatible(array, fp)) |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static void bpf_prog_select_func(struct bpf_prog *fp) |
| { |
| #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
| u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); |
| |
| fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; |
| #else |
| fp->bpf_func = __bpf_prog_ret0_warn; |
| #endif |
| } |
| |
| /** |
| * bpf_prog_select_runtime - select exec runtime for BPF program |
| * @fp: bpf_prog populated with internal BPF program |
| * @err: pointer to error variable |
| * |
| * Try to JIT eBPF program, if JIT is not available, use interpreter. |
| * The BPF program will be executed via BPF_PROG_RUN() macro. |
| */ |
| struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
| { |
| /* In case of BPF to BPF calls, verifier did all the prep |
| * work with regards to JITing, etc. |
| */ |
| if (fp->bpf_func) |
| goto finalize; |
| |
| bpf_prog_select_func(fp); |
| |
| /* eBPF JITs can rewrite the program in case constant |
| * blinding is active. However, in case of error during |
| * blinding, bpf_int_jit_compile() must always return a |
| * valid program, which in this case would simply not |
| * be JITed, but falls back to the interpreter. |
| */ |
| if (!bpf_prog_is_dev_bound(fp->aux)) { |
| *err = bpf_prog_alloc_jited_linfo(fp); |
| if (*err) |
| return fp; |
| |
| fp = bpf_int_jit_compile(fp); |
| if (!fp->jited) { |
| bpf_prog_free_jited_linfo(fp); |
| #ifdef CONFIG_BPF_JIT_ALWAYS_ON |
| *err = -ENOTSUPP; |
| return fp; |
| #endif |
| } else { |
| bpf_prog_free_unused_jited_linfo(fp); |
| } |
| } else { |
| *err = bpf_prog_offload_compile(fp); |
| if (*err) |
| return fp; |
| } |
| |
| finalize: |
| bpf_prog_lock_ro(fp); |
| |
| /* The tail call compatibility check can only be done at |
| * this late stage as we need to determine, if we deal |
| * with JITed or non JITed program concatenations and not |
| * all eBPF JITs might immediately support all features. |
| */ |
| *err = bpf_check_tail_call(fp); |
| |
| return fp; |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
| |
| static unsigned int __bpf_prog_ret1(const void *ctx, |
| const struct bpf_insn *insn) |
| { |
| return 1; |
| } |
| |
| static struct bpf_prog_dummy { |
| struct bpf_prog prog; |
| } dummy_bpf_prog = { |
| .prog = { |
| .bpf_func = __bpf_prog_ret1, |
| }, |
| }; |
| |
| /* to avoid allocating empty bpf_prog_array for cgroups that |
| * don't have bpf program attached use one global 'empty_prog_array' |
| * It will not be modified the caller of bpf_prog_array_alloc() |
| * (since caller requested prog_cnt == 0) |
| * that pointer should be 'freed' by bpf_prog_array_free() |
| */ |
| static struct { |
| struct bpf_prog_array hdr; |
| struct bpf_prog *null_prog; |
| } empty_prog_array = { |
| .null_prog = NULL, |
| }; |
| |
| struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) |
| { |
| if (prog_cnt) |
| return kzalloc(sizeof(struct bpf_prog_array) + |
| sizeof(struct bpf_prog_array_item) * |
| (prog_cnt + 1), |
| flags); |
| |
| return &empty_prog_array.hdr; |
| } |
| |
| void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) |
| { |
| if (!progs || |
| progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) |
| return; |
| kfree_rcu(progs, rcu); |
| } |
| |
| int bpf_prog_array_length(struct bpf_prog_array __rcu *array) |
| { |
| struct bpf_prog_array_item *item; |
| u32 cnt = 0; |
| |
| rcu_read_lock(); |
| item = rcu_dereference(array)->items; |
| for (; item->prog; item++) |
| if (item->prog != &dummy_bpf_prog.prog) |
| cnt++; |
| rcu_read_unlock(); |
| return cnt; |
| } |
| |
| |
| static bool bpf_prog_array_copy_core(struct bpf_prog_array __rcu *array, |
| u32 *prog_ids, |
| u32 request_cnt) |
| { |
| struct bpf_prog_array_item *item; |
| int i = 0; |
| |
| item = rcu_dereference_check(array, 1)->items; |
| for (; item->prog; item++) { |
| if (item->prog == &dummy_bpf_prog.prog) |
| continue; |
| prog_ids[i] = item->prog->aux->id; |
| if (++i == request_cnt) { |
| item++; |
| break; |
| } |
| } |
| |
| return !!(item->prog); |
| } |
| |
| int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *array, |
| __u32 __user *prog_ids, u32 cnt) |
| { |
| unsigned long err = 0; |
| bool nospc; |
| u32 *ids; |
| |
| /* users of this function are doing: |
| * cnt = bpf_prog_array_length(); |
| * if (cnt > 0) |
| * bpf_prog_array_copy_to_user(..., cnt); |
| * so below kcalloc doesn't need extra cnt > 0 check, but |
| * bpf_prog_array_length() releases rcu lock and |
| * prog array could have been swapped with empty or larger array, |
| * so always copy 'cnt' prog_ids to the user. |
| * In a rare race the user will see zero prog_ids |
| */ |
| ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); |
| if (!ids) |
| return -ENOMEM; |
| rcu_read_lock(); |
| nospc = bpf_prog_array_copy_core(array, ids, cnt); |
| rcu_read_unlock(); |
| err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); |
| kfree(ids); |
| if (err) |
| return -EFAULT; |
| if (nospc) |
| return -ENOSPC; |
| return 0; |
| } |
| |
| void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *array, |
| struct bpf_prog *old_prog) |
| { |
| struct bpf_prog_array_item *item = array->items; |
| |
| for (; item->prog; item++) |
| if (item->prog == old_prog) { |
| WRITE_ONCE(item->prog, &dummy_bpf_prog.prog); |
| break; |
| } |
| } |
| |
| int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, |
| struct bpf_prog *exclude_prog, |
| struct bpf_prog *include_prog, |
| struct bpf_prog_array **new_array) |
| { |
| int new_prog_cnt, carry_prog_cnt = 0; |
| struct bpf_prog_array_item *existing; |
| struct bpf_prog_array *array; |
| bool found_exclude = false; |
| int new_prog_idx = 0; |
| |
| /* Figure out how many existing progs we need to carry over to |
| * the new array. |
| */ |
| if (old_array) { |
| existing = old_array->items; |
| for (; existing->prog; existing++) { |
| if (existing->prog == exclude_prog) { |
| found_exclude = true; |
| continue; |
| } |
| if (existing->prog != &dummy_bpf_prog.prog) |
| carry_prog_cnt++; |
| if (existing->prog == include_prog) |
| return -EEXIST; |
| } |
| } |
| |
| if (exclude_prog && !found_exclude) |
| return -ENOENT; |
| |
| /* How many progs (not NULL) will be in the new array? */ |
| new_prog_cnt = carry_prog_cnt; |
| if (include_prog) |
| new_prog_cnt += 1; |
| |
| /* Do we have any prog (not NULL) in the new array? */ |
| if (!new_prog_cnt) { |
| *new_array = NULL; |
| return 0; |
| } |
| |
| /* +1 as the end of prog_array is marked with NULL */ |
| array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); |
| if (!array) |
| return -ENOMEM; |
| |
| /* Fill in the new prog array */ |
| if (carry_prog_cnt) { |
| existing = old_array->items; |
| for (; existing->prog; existing++) |
| if (existing->prog != exclude_prog && |
| existing->prog != &dummy_bpf_prog.prog) { |
| array->items[new_prog_idx++].prog = |
| existing->prog; |
| } |
| } |
| if (include_prog) |
| array->items[new_prog_idx++].prog = include_prog; |
| array->items[new_prog_idx].prog = NULL; |
| *new_array = array; |
| return 0; |
| } |
| |
| int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array, |
| u32 *prog_ids, u32 request_cnt, |
| u32 *prog_cnt) |
| { |
| u32 cnt = 0; |
| |
| if (array) |
| cnt = bpf_prog_array_length(array); |
| |
| *prog_cnt = cnt; |
| |
| /* return early if user requested only program count or nothing to copy */ |
| if (!request_cnt || !cnt) |
| return 0; |
| |
| /* this function is called under trace/bpf_trace.c: bpf_event_mutex */ |
| return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC |
| : 0; |
| } |
| |
| static void bpf_prog_free_deferred(struct work_struct *work) |
| { |
| struct bpf_prog_aux *aux; |
| int i; |
| |
| aux = container_of(work, struct bpf_prog_aux, work); |
| if (bpf_prog_is_dev_bound(aux)) |
| bpf_prog_offload_destroy(aux->prog); |
| #ifdef CONFIG_PERF_EVENTS |
| if (aux->prog->has_callchain_buf) |
| put_callchain_buffers(); |
| #endif |
| for (i = 0; i < aux->func_cnt; i++) |
| bpf_jit_free(aux->func[i]); |
| if (aux->func_cnt) { |
| kfree(aux->func); |
| bpf_prog_unlock_free(aux->prog); |
| } else { |
| bpf_jit_free(aux->prog); |
| } |
| } |
| |
| /* Free internal BPF program */ |
| void bpf_prog_free(struct bpf_prog *fp) |
| { |
| struct bpf_prog_aux *aux = fp->aux; |
| |
| INIT_WORK(&aux->work, bpf_prog_free_deferred); |
| schedule_work(&aux->work); |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_free); |
| |
| /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
| static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); |
| |
| void bpf_user_rnd_init_once(void) |
| { |
| prandom_init_once(&bpf_user_rnd_state); |
| } |
| |
| BPF_CALL_0(bpf_user_rnd_u32) |
| { |
| /* Should someone ever have the rather unwise idea to use some |
| * of the registers passed into this function, then note that |
| * this function is called from native eBPF and classic-to-eBPF |
| * transformations. Register assignments from both sides are |
| * different, f.e. classic always sets fn(ctx, A, X) here. |
| */ |
| struct rnd_state *state; |
| u32 res; |
| |
| state = &get_cpu_var(bpf_user_rnd_state); |
| res = prandom_u32_state(state); |
| put_cpu_var(bpf_user_rnd_state); |
| |
| return res; |
| } |
| |
| /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
| const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; |
| const struct bpf_func_proto bpf_map_update_elem_proto __weak; |
| const struct bpf_func_proto bpf_map_delete_elem_proto __weak; |
| const struct bpf_func_proto bpf_map_push_elem_proto __weak; |
| const struct bpf_func_proto bpf_map_pop_elem_proto __weak; |
| const struct bpf_func_proto bpf_map_peek_elem_proto __weak; |
| const struct bpf_func_proto bpf_spin_lock_proto __weak; |
| const struct bpf_func_proto bpf_spin_unlock_proto __weak; |
| |
| const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
| const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
| const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
| const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
| |
| const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
| const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; |
| const struct bpf_func_proto bpf_get_current_comm_proto __weak; |
| const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; |
| const struct bpf_func_proto bpf_get_local_storage_proto __weak; |
| |
| const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
| { |
| return NULL; |
| } |
| |
| u64 __weak |
| 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) |
| { |
| return -ENOTSUPP; |
| } |
| EXPORT_SYMBOL_GPL(bpf_event_output); |
| |
| /* Always built-in helper functions. */ |
| const struct bpf_func_proto bpf_tail_call_proto = { |
| .func = NULL, |
| .gpl_only = false, |
| .ret_type = RET_VOID, |
| .arg1_type = ARG_PTR_TO_CTX, |
| .arg2_type = ARG_CONST_MAP_PTR, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
| * It is encouraged to implement bpf_int_jit_compile() instead, so that |
| * eBPF and implicitly also cBPF can get JITed! |
| */ |
| struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
| { |
| return prog; |
| } |
| |
| /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
| * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). |
| */ |
| void __weak bpf_jit_compile(struct bpf_prog *prog) |
| { |
| } |
| |
| bool __weak bpf_helper_changes_pkt_data(void *func) |
| { |
| return false; |
| } |
| |
| /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
| * skb_copy_bits(), so provide a weak definition of it for NET-less config. |
| */ |
| int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, |
| int len) |
| { |
| return -EFAULT; |
| } |
| |
| DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); |
| EXPORT_SYMBOL(bpf_stats_enabled_key); |
| int sysctl_bpf_stats_enabled __read_mostly; |
| |
| /* All definitions of tracepoints related to BPF. */ |
| #define CREATE_TRACE_POINTS |
| #include <linux/bpf_trace.h> |
| |
| EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); |