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| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-10-09 03:47:25 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-10-09 20:29:12 +0000 |
| commit | c6477be1580445be005c8c249f00fc44eeca3190 (patch) | |
| tree | a1dde86e22a08a4fa49e87990b962fa78ba3380c /include | |
| parent | 30175f5d9b1a82e6664485bfe9e50e4dcaa6f2ac (diff) | |
| download | linux-next-c6477be1580445be005c8c249f00fc44eeca3190.tar.gz linux-next-c6477be1580445be005c8c249f00fc44eeca3190.zip | |
bpf: Summarize regs that may hold a frame pointer in insn_aux_data
SCEV needs to know which registers might be stack pointers at a
particular instruction. This information is used to avoid widening
registers if that would hinder further verification.
See the patch [1] for additional information.
liveness.c:compute_subprog_args() already tracks this information.
This commit modifies it to save the information in insn_aux_data for
further usage.
[1] "bpf: avoid widening registers that hinder exact stack-slot tracking"
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261009-scev-minimal-rebase-v3-7-bcba9bc53ac9@gmail.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf_verifier.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 5b615083ffa9..d31c1a500958 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -668,6 +668,7 @@ struct bpf_insn_aux_data { */ DECLARE_BITMAP(may_write_mask, MAX_BPF_STACK_SLOTS); DECLARE_BITMAP(live_stack_before, MAX_BPF_STACK_SLOTS); + u16 stack_ptrs; /* bitmask of regs that may hold a frame pointer here (arg_track) */ int ctx_field_size; /* the ctx field size for load insn, maybe 0 */ u32 seen; /* this insn was processed by the verifier at env->pass_cnt */ bool nospec; /* do not execute this instruction speculatively */ |