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author | Daniel Borkmann <daniel@iogearbox.net> | 2021-05-28 16:03:30 +0300 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-15 00:06:00 +0300 |
commit | d203b0fd863a2261e5d00b97f3d060c4c2a6db71 (patch) | |
tree | 79a6b6d2c2871044f0966d39cc875c76441f3b37 | |
parent | 11fc79fc9f2e395aa39fa5baccae62767c5d8280 (diff) | |
download | linux-d203b0fd863a2261e5d00b97f3d060c4c2a6db71.tar.xz |
bpf: Inherit expanded/patched seen count from old aux data
Instead of relying on current env->pass_cnt, use the seen count from the
old aux data in adjust_insn_aux_data(), and expand it to the new range of
patched instructions. This change is valid given we always expand 1:n
with n>=1, so what applies to the old/original instruction needs to apply
for the replacement as well.
Not relying on env->pass_cnt is a prerequisite for a later change where we
want to avoid marking an instruction seen when verified under speculative
execution path.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r-- | kernel/bpf/verifier.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 94ba5163d4c5..f93c7befb5dc 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11366,6 +11366,7 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; struct bpf_insn *insn = new_prog->insnsi; + u32 old_seen = old_data[off].seen; u32 prog_len; int i; @@ -11386,7 +11387,8 @@ static int adjust_insn_aux_data(struct bpf_verifier_env *env, memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); for (i = off; i < off + cnt - 1; i++) { - new_data[i].seen = env->pass_cnt; + /* Expand insni[off]'s seen count to the patched range. */ + new_data[i].seen = old_seen; new_data[i].zext_dst = insn_has_def32(env, insn + i); } env->insn_aux_data = new_data; |