Re: [PATCH bpf-next 06/12] bpf: Force JIT for programs using the R0:R2 register pair

[Yonghong Song <yonghong.song@linux.dev>]

On 7/9/26 1:30 PM, Eduard Zingerman wrote:
> On Wed, 2026-07-08 at 13:10 -0700, Yonghong Song wrote:
>
> [...]
>
>> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
>> index 73dc3ee879de..819a97d25173 100644
>> --- a/kernel/bpf/core.c
>> +++ b/kernel/bpf/core.c
>> @@ -2676,7 +2676,7 @@ struct bpf_prog *__bpf_prog_select_runtime(struct bpf_verifier_env *env, struct
>>   		goto finalize;
>>   
>>   	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
>> -	    bpf_prog_has_kfunc_call(fp))
>> +	    bpf_prog_has_kfunc_call(fp) || fp->aux->ret_reg_pair)
> This has a conflict with one of the very recent bpf-next commits.
> While reading locally I fixed the conflict by removing this hunk
> and adjusting bpf_ret_reg_pair_mark() as below.

Indeed, once jit_required is available in fp->aux, I can remove
ret_reg_pair things.

>
>>   		jit_needed = true;
>>   
>>   	if (!bpf_prog_select_interpreter(fp))
>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
>> index fcbf532159a5..ca8b2f436c20 100644
>> --- a/kernel/bpf/verifier.c
>> +++ b/kernel/bpf/verifier.c
>> @@ -453,6 +453,15 @@ bool bpf_ret_reg_pair(struct bpf_verifier_env *env, int subprog)
>>   	return false;
>>   }
>>   
>> +static bool bpf_ret_reg_pair_mark(struct bpf_verifier_env *env, int subprog)
>> +{
>> +	if (!bpf_ret_reg_pair(env, subprog))
>> +		return false;
>> +
>> +	env->prog->aux->ret_reg_pair = true;
> Added:
> 	env->prog->jit_required = true;
>
>> +	return true;
>> +}
>> +
> You probably would want to do the same in v2.
>
> [...]