On 11/22/22 5:06 PM, Yonghong Song wrote:
We should be okay here. flag is a local variable. It is used in
below function when reg_type is not SCALAR_VALUE.
static void mark_btf_ld_reg(struct bpf_verifier_env *env,
struct bpf_reg_state *regs, u32 regno,
enum bpf_reg_type reg_type,
struct btf *btf, u32 btf_id,
enum bpf_type_flag flag)
{
if (reg_type == SCALAR_VALUE) {
mark_reg_unknown(env, regs, regno);
Ah, got it.
@@ -11754,6 +11840,11 @@ static int check_ld_abs(struct bpf_verifier_env
*env, struct bpf_insn *insn)
return -EINVAL;
}
+ if (env->prog->aux->sleepable && env->cur_state->active_rcu_lock) {
I don't know the details about ld_abs :). Why sleepable check is needed here?
Do we still care about ld_abs??
Actually I added this since spin_lock excludes this. But taking a deep
From looking at check_ld_abs() again, I just noticed this comment:
/* Disallow usage of BPF_LD_[ABS|IND] with reference tracking, as
* gen_ld_abs() may terminate the program at runtime, leading to
* reference leak.
*/
I think active_rcu_lock should be tested. My question was more on why the
env->prog->aux->sleepable test is also needed.
