[PATCH 16/26] bpf: Use sha1() instead of sha1_transform() in bpf_prog_calc_tag()
From: Eric Biggers <ebiggers@kernel.org>
Date: 2025-07-12 23:26:27
Also in:
linux-arm-kernel, linux-crypto, linux-mips, linux-s390, lkml, sparclinux
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Now that there's a proper SHA-1 library API, just use that instead of the low-level SHA-1 compression function. This eliminates the need for bpf_prog_calc_tag() to implement the SHA-1 padding itself. No functional change. Signed-off-by: Eric Biggers <ebiggers@kernel.org> --- include/linux/filter.h | 6 ------ kernel/bpf/core.c | 49 +++++++----------------------------------- 2 files changed, 8 insertions(+), 47 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index f5cf4d35d83e9..3aa33e904a4ed 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h@@ -995,16 +995,10 @@ void bpf_prog_change_xdp(struct bpf_prog *prev_prog, struct bpf_prog *prog); static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) { return prog->len * sizeof(struct bpf_insn); } -static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) -{ - return round_up(bpf_prog_insn_size(prog) + - sizeof(__be64) + 1, SHA1_BLOCK_SIZE); -} - static inline unsigned int bpf_prog_size(unsigned int proglen) { return max(sizeof(struct bpf_prog), offsetof(struct bpf_prog, insns[proglen])); }
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index dae281a1286d5..a1b727ffa4548 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c@@ -287,32 +287,23 @@ void __bpf_prog_free(struct bpf_prog *fp) vfree(fp); } int bpf_prog_calc_tag(struct bpf_prog *fp) { - const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64); - u32 raw_size = bpf_prog_tag_scratch_size(fp); - u32 digest[SHA1_DIGEST_WORDS]; - u32 ws[SHA1_WORKSPACE_WORDS]; - u32 i, bsize, psize, blocks; + size_t size = bpf_prog_insn_size(fp); + u8 digest[SHA1_DIGEST_SIZE]; struct bpf_insn *dst; bool was_ld_map; - u8 *raw, *todo; - __be32 *result; - __be64 *bits; + u32 i; - raw = vmalloc(raw_size); - if (!raw) + dst = vmalloc(size); + if (!dst) return -ENOMEM; - sha1_init_raw(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 ||
@@ -328,37 +319,13 @@ int bpf_prog_calc_tag(struct bpf_prog *fp) 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, SHA1_BLOCK_SIZE); - blocks = bsize / SHA1_BLOCK_SIZE; - 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--) { - sha1_transform(digest, todo, ws); - todo += SHA1_BLOCK_SIZE; - } - - result = (__force __be32 *)digest; - for (i = 0; i < SHA1_DIGEST_WORDS; i++) - result[i] = cpu_to_be32(digest[i]); - memcpy(fp->tag, result, sizeof(fp->tag)); - - vfree(raw); + sha1((const u8 *)dst, size, digest); + memcpy(fp->tag, digest, sizeof(fp->tag)); + vfree(dst); 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)
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2.50.1