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bpf: use compute_live_registers() info in clean_func_state

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Prepare for bpf_reg_state->live field removal by leveraging
insn_aux_data->live_regs_before instead of bpf_reg_state->live in
compute_live_registers(). This is similar to logic in
func_states_equal(). No changes in verification performance for
selftests or sched_ext.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-2-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Eduard Zingerman
2025-09-18 19:18:35 -07:00
committed by Alexei Starovoitov
parent daf4c2929f
commit 6cd21eb9ad
1 changed files with 9 additions and 6 deletions
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15
kernel/bpf/verifier.c
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@@ -18489,15 +18489,16 @@ static bool check_scalar_ids(u32 old_id, u32 cur_id, struct bpf_idmap *idmap)
}
static void clean_func_state(struct bpf_verifier_env *env,
struct bpf_func_state *st)
struct bpf_func_state *st,
u32 ip)
{
u16 live_regs = env->insn_aux_data[ip].live_regs_before;
enum bpf_reg_liveness live;
int i, j;
for (i = 0; i < BPF_REG_FP; i++) {
live = st->regs[i].live;
/* liveness must not touch this register anymore */
if (!(live & REG_LIVE_READ))
if (!(live_regs & BIT(i)))
/* since the register is unused, clear its state
* to make further comparison simpler
*/
@@ -18518,11 +18519,13 @@ static void clean_func_state(struct bpf_verifier_env *env,
static void clean_verifier_state(struct bpf_verifier_env *env,
struct bpf_verifier_state *st)
{
int i;
int i, ip;
st->cleaned = true;
for (i = 0; i <= st->curframe; i++)
clean_func_state(env, st->frame[i]);
for (i = 0; i <= st->curframe; i++) {
ip = frame_insn_idx(st, i);
clean_func_state(env, st->frame[i], ip);
}
}
/* the parentage chains form a tree.