diff options
| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-24 18:57:06 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-24 18:04:45 +0000 |
| commit | ec373f1f0788a498a56ea73884bfe6ce23969d7e (patch) | |
| tree | f2d9e2bd26ca2c41f0c672034ac7dfd5414bd074 /include/linux | |
| parent | 765e7328d64dec47a33fd7ac8c070b411297c275 (diff) | |
bpf: Track scratched stack slots with a bitmap
The set of stack slots touched since the verifier state was last
printed lives in a u64, so the log could only ever mark the first 64
slots of a frame as scratched. Make it a bitmap sized by
MAX_BPF_STACK_SLOTS and go through the bitmap helpers for setting,
testing, clearing and filling it.
No functional change.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260924165740.2146806-6-memxor@gmail.com
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bpf_verifier.h | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 781dc5ca1fe2..e64cfb3fe675 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -1092,7 +1092,7 @@ struct bpf_verifier_env { */ u32 scratched_regs; /* Same as scratched_regs but for stack slots */ - u64 scratched_stack_slots; + DECLARE_BITMAP(scratched_stack_slots, MAX_BPF_STACK_SLOTS); u64 prev_log_pos, prev_insn_print_pos; /* buffer used to temporary hold constants as scalar registers */ struct bpf_reg_state fake_reg[1]; @@ -1520,7 +1520,7 @@ static inline void mark_reg_scratched(struct bpf_verifier_env *env, u32 regno) static inline void mark_stack_slot_scratched(struct bpf_verifier_env *env, u32 spi) { - env->scratched_stack_slots |= 1ULL << spi; + __set_bit(spi, env->scratched_stack_slots); } static inline bool reg_scratched(const struct bpf_verifier_env *env, u32 regno) @@ -1528,27 +1528,28 @@ static inline bool reg_scratched(const struct bpf_verifier_env *env, u32 regno) return (env->scratched_regs >> regno) & 1; } -static inline bool stack_slot_scratched(const struct bpf_verifier_env *env, u64 regno) +static inline bool stack_slot_scratched(const struct bpf_verifier_env *env, u32 spi) { - return (env->scratched_stack_slots >> regno) & 1; + return test_bit(spi, env->scratched_stack_slots); } static inline bool verifier_state_scratched(const struct bpf_verifier_env *env) { - return env->scratched_regs || env->scratched_stack_slots; + return env->scratched_regs || + !bitmap_empty(env->scratched_stack_slots, MAX_BPF_STACK_SLOTS); } static inline void mark_verifier_state_clean(struct bpf_verifier_env *env) { env->scratched_regs = 0U; - env->scratched_stack_slots = 0ULL; + bitmap_zero(env->scratched_stack_slots, MAX_BPF_STACK_SLOTS); } /* Used for printing the entire verifier state. */ static inline void mark_verifier_state_scratched(struct bpf_verifier_env *env) { env->scratched_regs = ~0U; - env->scratched_stack_slots = ~0ULL; + bitmap_fill(env->scratched_stack_slots, MAX_BPF_STACK_SLOTS); } static inline bool bpf_stack_narrow_access_ok(int off, int fill_size, int spill_size) |