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| author | Alexei Starovoitov <ast@kernel.org> | 2026-03-10 11:51:18 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-03-10 11:51:27 -0700 |
| commit | 437350df8640bf0535b74a3d8bade6f707940027 (patch) | |
| tree | 977d0899d15ac4412007b7c2df54b734e8d5763b /kernel | |
| parent | bd2e02e3c9215305dfa344c050d5822f19929cf7 (diff) | |
| parent | 6a1c9a442f634e7b95c5ad0927870335b1ce299e (diff) | |
Merge branch 'bpf-support-for-non_null-ptr-detection-with-jeq-jne-with-register-operand'
Cupertino Miranda says:
====================
bpf: support for non_null ptr detection with JEQ/JNE with register operand
Changes from v1:
- Corrected typos in commit messages.
- Fixed indentation.
- Replaced text by simpler version suggested by Eduard.
Changes from v2:
- Small fixes after AI patch checker complaints.
Changes from v3:
- Removed log file. No idea how that got added.
====================
Link: https://patch.msgid.link/20260304195018.181396-1-cupertino.miranda@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 8e4f69918693..4fbacd2149cd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -17678,12 +17678,15 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, } /* detect if R == 0 where R is returned from bpf_map_lookup_elem(). + * Also does the same detection for a register whose the value is + * known to be 0. * NOTE: these optimizations below are related with pointer comparison * which will never be JMP32. */ - if (!is_jmp32 && BPF_SRC(insn->code) == BPF_K && - insn->imm == 0 && (opcode == BPF_JEQ || opcode == BPF_JNE) && - type_may_be_null(dst_reg->type)) { + if (!is_jmp32 && (opcode == BPF_JEQ || opcode == BPF_JNE) && + type_may_be_null(dst_reg->type) && + ((BPF_SRC(insn->code) == BPF_K && insn->imm == 0) || + (BPF_SRC(insn->code) == BPF_X && register_is_null(src_reg)))) { /* Mark all identical registers in each branch as either * safe or unknown depending R == 0 or R != 0 conditional. */ |