| /* |
| * 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> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Andi Kleen - Fix a few bad bugs and races. |
| * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
| */ |
| |
| #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/frame.h> |
| #include <linux/rbtree_latch.h> |
| #include <linux/kallsyms.h> |
| #include <linux/rcupdate.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 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(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; |
| |
| INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
| |
| return fp; |
| } |
| EXPORT_SYMBOL_GPL(bpf_prog_alloc); |
| |
| 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) |
| { |
| 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) { |
| 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 bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) |
| { |
| return BPF_CLASS(insn->code) == BPF_JMP && |
| /* Call and Exit are both special jumps with no |
| * target inside the BPF instruction image. |
| */ |
| BPF_OP(insn->code) != BPF_CALL && |
| BPF_OP(insn->code) != BPF_EXIT; |
| } |
| |
| static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) |
| { |
| struct bpf_insn *insn = prog->insnsi; |
| u32 i, insn_cnt = prog->len; |
| |
| for (i = 0; i < insn_cnt; i++, insn++) { |
| if (!bpf_is_jmp_and_has_target(insn)) |
| continue; |
| |
| /* Adjust offset of jmps if we cross boundaries. */ |
| if (i < pos && i + insn->off + 1 > pos) |
| insn->off += delta; |
| else if (i > pos + delta && i + insn->off + 1 <= pos + delta) |
| 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; |
| struct bpf_prog *prog_adj; |
| |
| /* 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; |
| |
| /* 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 NULL; |
| |
| 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); |
| |
| bpf_adj_branches(prog_adj, off, insn_delta); |
| |
| return prog_adj; |
| } |
| |
| #ifdef CONFIG_BPF_JIT |
| 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; |
| } |
| |
| static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) |
| { |
| const char *end = sym + KSYM_NAME_LEN; |
| |
| 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)); |
| 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; |
| |
| int bpf_jit_kallsyms __read_mostly; |
| |
| 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) |
| { |
| unsigned long symbol_start, symbol_end; |
| 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_addr_region(aux->prog, &symbol_start, &symbol_end); |
| bpf_get_prog_name(aux->prog, sym); |
| |
| *value = symbol_start; |
| *type = BPF_SYM_ELF_TYPE; |
| |
| ret = 0; |
| break; |
| } |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| 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; |
| unsigned int size, hole, start; |
| |
| /* 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); |
| hdr = module_alloc(size); |
| if (hdr == NULL) |
| return NULL; |
| |
| /* Fill space with illegal/arch-dep instructions. */ |
| bpf_fill_ill_insns(hdr, size); |
| |
| hdr->pages = size / PAGE_SIZE; |
| 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) |
| { |
| module_memfree(hdr); |
| } |
| |
| /* 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_unlock_ro(hdr); |
| bpf_jit_binary_free(hdr); |
| |
| WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); |
| } |
| |
| bpf_prog_unlock_free(fp); |
| } |
| |
| int bpf_jit_harden __read_mostly; |
| |
| 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); |
| |
| 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_LD | BPF_ABS | BPF_W: |
| case BPF_LD | BPF_ABS | BPF_H: |
| case BPF_LD | BPF_ABS | 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_LD_IND(from->code, BPF_REG_AX, 0); |
| break; |
| |
| case BPF_LD | BPF_IND | BPF_W: |
| case BPF_LD | BPF_IND | BPF_H: |
| case BPF_LD | BPF_IND | 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_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); |
| *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); |
| 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()) |
| 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 (!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 ERR_PTR(-ENOMEM); |
| } |
| |
| 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; |
| } |
| |
| 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. |
| */ |
| noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) |
| { |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(__bpf_call_base); |
| |
| #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
| /** |
| * __bpf_prog_run - run eBPF program on a given context |
| * @ctx: is the data we are operating on |
| * @insn: is the array of eBPF instructions |
| * |
| * Decode and execute eBPF instructions. |
| */ |
| static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, |
| u64 *stack) |
| { |
| u64 tmp; |
| static const void *jumptable[256] = { |
| [0 ... 255] = &&default_label, |
| /* Now overwrite non-defaults ... */ |
| /* 32 bit ALU operations */ |
| [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, |
| [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, |
| [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, |
| [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, |
| [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, |
| [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, |
| [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, |
| [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, |
| [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, |
| [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, |
| [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, |
| [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, |
| [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, |
| [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, |
| [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, |
| [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, |
| [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, |
| [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, |
| [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, |
| [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, |
| [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, |
| [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, |
| [BPF_ALU | BPF_NEG] = &&ALU_NEG, |
| [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, |
| [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, |
| /* 64 bit ALU operations */ |
| [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, |
| [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, |
| [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, |
| [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, |
| [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, |
| [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, |
| [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, |
| [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, |
| [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, |
| [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, |
| [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, |
| [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, |
| [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, |
| [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, |
| [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, |
| [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, |
| [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, |
| [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, |
| [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, |
| [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, |
| [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, |
| [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, |
| [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, |
| [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, |
| [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, |
| /* Call instruction */ |
| [BPF_JMP | BPF_CALL] = &&JMP_CALL, |
| [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
| /* Jumps */ |
| [BPF_JMP | BPF_JA] = &&JMP_JA, |
| [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, |
| [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, |
| [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, |
| [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, |
| [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, |
| [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, |
| [BPF_JMP | BPF_JLT | BPF_X] = &&JMP_JLT_X, |
| [BPF_JMP | BPF_JLT | BPF_K] = &&JMP_JLT_K, |
| [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, |
| [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, |
| [BPF_JMP | BPF_JLE | BPF_X] = &&JMP_JLE_X, |
| [BPF_JMP | BPF_JLE | BPF_K] = &&JMP_JLE_K, |
| [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, |
| [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, |
| [BPF_JMP | BPF_JSLT | BPF_X] = &&JMP_JSLT_X, |
| [BPF_JMP | BPF_JSLT | BPF_K] = &&JMP_JSLT_K, |
| [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, |
| [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, |
| [BPF_JMP | BPF_JSLE | BPF_X] = &&JMP_JSLE_X, |
| [BPF_JMP | BPF_JSLE | BPF_K] = &&JMP_JSLE_K, |
| [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, |
| [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, |
| /* Program return */ |
| [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, |
| /* Store instructions */ |
| [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, |
| [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, |
| [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, |
| [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, |
| [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, |
| [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, |
| [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, |
| [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, |
| [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, |
| [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, |
| /* Load instructions */ |
| [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, |
| [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, |
| [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, |
| [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, |
| [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, |
| [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, |
| [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, |
| [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, |
| [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, |
| [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, |
| [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
| }; |
| u32 tail_call_cnt = 0; |
| void *ptr; |
| int off; |
| |
| #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; |
| ALU64_ARSH_X: |
| (*(s64 *) &DST) >>= SRC; |
| CONT; |
| ALU64_ARSH_K: |
| (*(s64 *) &DST) >>= IMM; |
| CONT; |
| ALU64_MOD_X: |
| if (unlikely(SRC == 0)) |
| return 0; |
| div64_u64_rem(DST, SRC, &tmp); |
| DST = tmp; |
| CONT; |
| ALU_MOD_X: |
| if (unlikely(SRC == 0)) |
| return 0; |
| tmp = (u32) DST; |
| DST = do_div(tmp, (u32) SRC); |
| CONT; |
| ALU64_MOD_K: |
| div64_u64_rem(DST, IMM, &tmp); |
| DST = tmp; |
| CONT; |
| ALU_MOD_K: |
| tmp = (u32) DST; |
| DST = do_div(tmp, (u32) IMM); |
| CONT; |
| ALU64_DIV_X: |
| if (unlikely(SRC == 0)) |
| return 0; |
| DST = div64_u64(DST, SRC); |
| CONT; |
| ALU_DIV_X: |
| if (unlikely(SRC == 0)) |
| return 0; |
| tmp = (u32) DST; |
| do_div(tmp, (u32) SRC); |
| DST = (u32) tmp; |
| CONT; |
| ALU64_DIV_K: |
| DST = div64_u64(DST, IMM); |
| CONT; |
| ALU_DIV_K: |
| tmp = (u32) DST; |
| do_div(tmp, (u32) IMM); |
| DST = (u32) tmp; |
| 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_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 */ |
| JMP_JA: |
| insn += insn->off; |
| CONT; |
| JMP_JEQ_X: |
| if (DST == SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JEQ_K: |
| if (DST == IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JNE_X: |
| if (DST != SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JNE_K: |
| if (DST != IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JGT_X: |
| if (DST > SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JGT_K: |
| if (DST > IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JLT_X: |
| if (DST < SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JLT_K: |
| if (DST < IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JGE_X: |
| if (DST >= SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JGE_K: |
| if (DST >= IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JLE_X: |
| if (DST <= SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JLE_K: |
| if (DST <= IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSGT_X: |
| if (((s64) DST) > ((s64) SRC)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSGT_K: |
| if (((s64) DST) > ((s64) IMM)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSLT_X: |
| if (((s64) DST) < ((s64) SRC)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSLT_K: |
| if (((s64) DST) < ((s64) IMM)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSGE_X: |
| if (((s64) DST) >= ((s64) SRC)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSGE_K: |
| if (((s64) DST) >= ((s64) IMM)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSLE_X: |
| if (((s64) DST) <= ((s64) SRC)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSLE_K: |
| if (((s64) DST) <= ((s64) IMM)) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSET_X: |
| if (DST & SRC) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_JSET_K: |
| if (DST & IMM) { |
| insn += insn->off; |
| CONT_JMP; |
| } |
| CONT; |
| JMP_EXIT: |
| return BPF_R0; |
| |
| /* 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; |
| LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ |
| off = IMM; |
| load_word: |
| /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
| * appearing in the programs where ctx == skb |
| * (see may_access_skb() in the verifier). All programs |
| * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, |
| * bpf_convert_filter() saves it in BPF_R6, internal BPF |
| * verifier will check that BPF_R6 == ctx. |
| * |
| * BPF_ABS and BPF_IND are wrappers of function calls, |
| * so they scratch BPF_R1-BPF_R5 registers, preserve |
| * BPF_R6-BPF_R9, and store return value into BPF_R0. |
| * |
| * Implicit input: |
| * ctx == skb == BPF_R6 == CTX |
| * |
| * Explicit input: |
| * SRC == any register |
| * IMM == 32-bit immediate |
| * |
| * Output: |
| * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness |
| */ |
| |
| ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); |
| if (likely(ptr != NULL)) { |
| BPF_R0 = get_unaligned_be32(ptr); |
| CONT; |
| } |
| |
| return 0; |
| LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ |
| off = IMM; |
| load_half: |
| ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); |
| if (likely(ptr != NULL)) { |
| BPF_R0 = get_unaligned_be16(ptr); |
| CONT; |
| } |
| |
| return 0; |
| LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ |
| off = IMM; |
| load_byte: |
| ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); |
| if (likely(ptr != NULL)) { |
| BPF_R0 = *(u8 *)ptr; |
| CONT; |
| } |
| |
| return 0; |
| LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ |
| off = IMM + SRC; |
| goto load_word; |
| LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ |
| off = IMM + SRC; |
| goto load_half; |
| LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ |
| off = IMM + SRC; |
| goto load_byte; |
| |
| default_label: |
| /* If we ever reach this, we have a bug somewhere. */ |
| WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); |
| 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_REG]; \ |
| \ |
| FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ |
| ARG1 = (u64) (unsigned long) ctx; \ |
| 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); |
| |
| #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) |
| }; |
| |
| #else |
| static unsigned int __bpf_prog_ret0(const void *ctx, |
| const struct bpf_insn *insn) |
| { |
| return 0; |
| } |
| #endif |
| |
| bool bpf_prog_array_compatible(struct bpf_array *array, |
| const struct bpf_prog *fp) |
| { |
| 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; |
| } |
| |
| /** |
| * 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) |
| { |
| #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; |
| #endif |
| |
| /* 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)) { |
| fp = bpf_int_jit_compile(fp); |
| #ifdef CONFIG_BPF_JIT_ALWAYS_ON |
| if (!fp->jited) { |
| *err = -ENOTSUPP; |
| return fp; |
| } |
| #endif |
| } else { |
| *err = bpf_prog_offload_compile(fp); |
| if (*err) |
| return fp; |
| } |
| 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 __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) |
| { |
| if (prog_cnt) |
| return kzalloc(sizeof(struct bpf_prog_array) + |
| sizeof(struct bpf_prog *) * (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 *progs) |
| { |
| struct bpf_prog **prog; |
| u32 cnt = 0; |
| |
| rcu_read_lock(); |
| prog = rcu_dereference(progs)->progs; |
| for (; *prog; prog++) |
| if (*prog != &dummy_bpf_prog.prog) |
| cnt++; |
| rcu_read_unlock(); |
| return cnt; |
| } |
| |
| int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, |
| __u32 __user *prog_ids, u32 cnt) |
| { |
| struct bpf_prog **prog; |
| u32 i = 0, id; |
| |
| rcu_read_lock(); |
| prog = rcu_dereference(progs)->progs; |
| for (; *prog; prog++) { |
| id = (*prog)->aux->id; |
| if (copy_to_user(prog_ids + i, &id, sizeof(id))) { |
| rcu_read_unlock(); |
| return -EFAULT; |
| } |
| if (++i == cnt) { |
| prog++; |
| break; |
| } |
| } |
| rcu_read_unlock(); |
| if (*prog) |
| return -ENOSPC; |
| return 0; |
| } |
| |
| void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, |
| struct bpf_prog *old_prog) |
| { |
| struct bpf_prog **prog = progs->progs; |
| |
| for (; *prog; prog++) |
| if (*prog == old_prog) { |
| WRITE_ONCE(*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 **existing_prog; |
| struct bpf_prog_array *array; |
| int new_prog_idx = 0; |
| |
| /* Figure out how many existing progs we need to carry over to |
| * the new array. |
| */ |
| if (old_array) { |
| existing_prog = old_array->progs; |
| for (; *existing_prog; existing_prog++) { |
| if (*existing_prog != exclude_prog && |
| *existing_prog != &dummy_bpf_prog.prog) |
| carry_prog_cnt++; |
| if (*existing_prog == include_prog) |
| return -EEXIST; |
| } |
| } |
| |
| /* 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_prog = old_array->progs; |
| for (; *existing_prog; existing_prog++) |
| if (*existing_prog != exclude_prog && |
| *existing_prog != &dummy_bpf_prog.prog) |
| array->progs[new_prog_idx++] = *existing_prog; |
| } |
| if (include_prog) |
| array->progs[new_prog_idx++] = include_prog; |
| array->progs[new_prog_idx] = NULL; |
| *new_array = array; |
| return 0; |
| } |
| |
| static void bpf_prog_free_deferred(struct work_struct *work) |
| { |
| struct bpf_prog_aux *aux; |
| |
| aux = container_of(work, struct bpf_prog_aux, work); |
| if (bpf_prog_is_dev_bound(aux)) |
| bpf_prog_offload_destroy(aux->prog); |
| 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_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_sock_map_update_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; |
| } |
| |
| /* 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; |
| } |
| |
| /* All definitions of tracepoints related to BPF. */ |
| #define CREATE_TRACE_POINTS |
| #include <linux/bpf_trace.h> |
| |
| EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); |
| |
| /* These are only used within the BPF_SYSCALL code */ |
| #ifdef CONFIG_BPF_SYSCALL |
| EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); |
| EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); |
| #endif |