diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 69d0a7f12a3bd516ef295c72153f7abcea56c0f3..8796ff03f4729f953d4a888163bf5b559225aa35 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -216,6 +216,7 @@ u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); bool bpf_prog_array_compatible(struct bpf_array *array, const struct bpf_prog *fp); +void bpf_prog_calc_digest(struct bpf_prog *fp); const struct bpf_func_proto *bpf_get_trace_printk_proto(void); diff --git a/include/linux/filter.h b/include/linux/filter.h index 97338134398f678bb96515df98960325fc09f85e..f078d2b1cff6a7c80f97cfb5fad7da966a64af86 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -14,6 +14,7 @@ #include #include #include +#include #include @@ -56,6 +57,9 @@ struct bpf_prog_aux; /* BPF program can access up to 512 bytes of stack space. */ #define MAX_BPF_STACK 512 +/* Maximum BPF program size in bytes. */ +#define MAX_BPF_SIZE (BPF_MAXINSNS * sizeof(struct bpf_insn)) + /* Helper macros for filter block array initializers. */ /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ @@ -404,8 +408,9 @@ struct bpf_prog { cb_access:1, /* Is control block accessed? */ dst_needed:1; /* Do we need dst entry? */ kmemcheck_bitfield_end(meta); - u32 len; /* Number of filter blocks */ enum bpf_prog_type type; /* Type of BPF program */ + u32 len; /* Number of filter blocks */ + u32 digest[SHA_DIGEST_WORDS]; /* Program digest */ struct bpf_prog_aux *aux; /* Auxiliary fields */ struct sock_fprog_kern *orig_prog; /* Original BPF program */ unsigned int (*bpf_func)(const void *ctx, diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index 86786d45ee66de3b573c2d10a685782f00d700af..1adc0b654996c1cd88cadbbfc6487c46095a1a48 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -397,6 +397,7 @@ enum { TCA_BPF_NAME, TCA_BPF_FLAGS, TCA_BPF_FLAGS_GEN, + TCA_BPF_DIGEST, __TCA_BPF_MAX, }; diff --git a/include/uapi/linux/tc_act/tc_bpf.h b/include/uapi/linux/tc_act/tc_bpf.h index 063d9d465119b2519f87aa4e31961311acf026e0..a6b88a6f7f712b271f07e809ee7a79697e6cb8cf 100644 --- a/include/uapi/linux/tc_act/tc_bpf.h +++ b/include/uapi/linux/tc_act/tc_bpf.h @@ -27,6 +27,7 @@ enum { TCA_ACT_BPF_FD, TCA_ACT_BPF_NAME, TCA_ACT_BPF_PAD, + TCA_ACT_BPF_DIGEST, __TCA_ACT_BPF_MAX, }; #define TCA_ACT_BPF_MAX (__TCA_ACT_BPF_MAX - 1) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 82a04143368ef0a29fe6c9d8a3321d098d95c758..bdcc9f4ba7678a077c554c63963935a562796d5f 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -136,6 +136,71 @@ void __bpf_prog_free(struct bpf_prog *fp) vfree(fp); } +#define SHA_BPF_RAW_SIZE \ + round_up(MAX_BPF_SIZE + sizeof(__be64) + 1, SHA_MESSAGE_BYTES) + +/* Called under verifier mutex. */ +void bpf_prog_calc_digest(struct bpf_prog *fp) +{ + const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); + static u32 ws[SHA_WORKSPACE_WORDS]; + static u8 raw[SHA_BPF_RAW_SIZE]; + struct bpf_insn *dst = (void *)raw; + u32 i, bsize, psize, blocks; + bool was_ld_map; + u8 *todo = raw; + __be32 *result; + __be64 *bits; + + sha_init(fp->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. + */ + 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 = fp->len * sizeof(struct bpf_insn); + memset(&raw[psize], 0, sizeof(raw) - psize); + raw[psize++] = 0x80; + + bsize = round_up(psize, SHA_MESSAGE_BYTES); + blocks = bsize / SHA_MESSAGE_BYTES; + 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(fp->digest, todo, ws); + todo += SHA_MESSAGE_BYTES; + } + + result = (__force __be32 *)fp->digest; + for (i = 0; i < SHA_DIGEST_WORDS; i++) + result[i] = cpu_to_be32(fp->digest[i]); +} + static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) { return BPF_CLASS(insn->code) == BPF_JMP && diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 85af86c496cdeed8bb1ce49db3295e0b199ae403..c0d2b423ce931e9a0e332fccd3c3e6bd78ba1b22 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -662,8 +662,30 @@ static int bpf_prog_release(struct inode *inode, struct file *filp) return 0; } +#ifdef CONFIG_PROC_FS +static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) +{ + const struct bpf_prog *prog = filp->private_data; + char prog_digest[sizeof(prog->digest) * 2 + 1] = { }; + + bin2hex(prog_digest, prog->digest, sizeof(prog->digest)); + seq_printf(m, + "prog_type:\t%u\n" + "prog_jited:\t%u\n" + "prog_digest:\t%s\n" + "memlock:\t%llu\n", + prog->type, + prog->jited, + prog_digest, + prog->pages * 1ULL << PAGE_SHIFT); +} +#endif + static const struct file_operations bpf_prog_fops = { - .release = bpf_prog_release, +#ifdef CONFIG_PROC_FS + .show_fdinfo = bpf_prog_show_fdinfo, +#endif + .release = bpf_prog_release, }; int bpf_prog_new_fd(struct bpf_prog *prog) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 38d05da84a49508d80bee58c71f7c77011b6a243..cb37339ca0dac5f282ab3daca0a65a299479b7b9 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3176,6 +3176,8 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) log_level = 0; } + bpf_prog_calc_digest(env->prog); + ret = replace_map_fd_with_map_ptr(env); if (ret < 0) goto skip_full_check; diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c index 84c1d2da4f8b0576fde83e66ab0664d4e9d4e557..1c60317f01214ad77c17415bb2d7bc194b124615 100644 --- a/net/sched/act_bpf.c +++ b/net/sched/act_bpf.c @@ -117,10 +117,19 @@ static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog, static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog, struct sk_buff *skb) { + struct nlattr *nla; + if (prog->bpf_name && nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) return -EMSGSIZE; + nla = nla_reserve(skb, TCA_ACT_BPF_DIGEST, + sizeof(prog->filter->digest)); + if (nla == NULL) + return -EMSGSIZE; + + memcpy(nla_data(nla), prog->filter->digest, nla_len(nla)); + return 0; } diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index f70e03d2d2c8a99fc05167adf76715fa2c3dad90..adc776048d1a899f7955d0a92dd48b374178f3bb 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -549,10 +549,18 @@ static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog, static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog, struct sk_buff *skb) { + struct nlattr *nla; + if (prog->bpf_name && nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name)) return -EMSGSIZE; + nla = nla_reserve(skb, TCA_BPF_DIGEST, sizeof(prog->filter->digest)); + if (nla == NULL) + return -EMSGSIZE; + + memcpy(nla_data(nla), prog->filter->digest, nla_len(nla)); + return 0; }