@@ -8500,49 +8500,30 @@ verifier_linearize_list_insn(struct bpf_verifier_env *env,
return ret_env;
}
-static int opt_remove_dead_code(struct bpf_verifier_env *env)
+static int opt_remove_useless_code(struct bpf_verifier_env *env)
{
- struct bpf_insn_aux_data *aux_data = env->insn_aux_data;
- int insn_cnt = env->prog->len;
- int i, err;
-
- for (i = 0; i < insn_cnt; i++) {
- int j;
-
- j = 0;
- while (i + j < insn_cnt && !aux_data[i + j].seen)
- j++;
- if (!j)
- continue;
-
- err = verifier_remove_insns(env, i, j);
- if (err)
- return err;
- insn_cnt = env->prog->len;
- }
-
- return 0;
-}
-
-static int opt_remove_nops(struct bpf_verifier_env *env)
-{
- const struct bpf_insn ja = BPF_JMP_IMM(BPF_JA, 0, 0, 0);
- struct bpf_insn *insn = env->prog->insnsi;
- int insn_cnt = env->prog->len;
- int i, err;
+ struct bpf_insn_aux_data *auxs = env->insn_aux_data;
+ const struct bpf_insn nop =
+ BPF_JMP_IMM(BPF_JA, 0, 0, 0);
+ struct bpf_list_insn *list, *elem;
+ int ret = 0;
- for (i = 0; i < insn_cnt; i++) {
- if (memcmp(&insn[i], &ja, sizeof(ja)))
+ list = bpf_create_list_insn(env->prog);
+ if (IS_ERR(list))
+ return PTR_ERR(list);
+ for (elem = list; elem; elem = elem->next) {
+ if (auxs[elem->orig_idx - 1].seen &&
+ memcmp(&elem->insn, &nop, sizeof(nop)))
continue;
- err = verifier_remove_insns(env, i, 1);
- if (err)
- return err;
- insn_cnt--;
- i--;
+ elem->flag |= LIST_INSN_FLAG_REMOVED;
}
- return 0;
+ env = verifier_linearize_list_insn(env, list);
+ if (IS_ERR(env))
+ ret = PTR_ERR(env);
+ bpf_destroy_list_insn(list);
+ return ret;
}
static int opt_subreg_zext_lo32_rnd_hi32(struct bpf_verifier_env *env,
@@ -9488,9 +9469,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (ret == 0)
opt_hard_wire_dead_code_branches(env);
if (ret == 0)
- ret = opt_remove_dead_code(env);
- if (ret == 0)
- ret = opt_remove_nops(env);
+ ret = opt_remove_useless_code(env);
} else {
if (ret == 0)
sanitize_dead_code(env);
This patch migrate dead code remove pass to new list patching infrastructure. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> --- kernel/bpf/verifier.c | 59 +++++++++++++++++---------------------------------- 1 file changed, 19 insertions(+), 40 deletions(-)