Re: [PATCH bpf-next v1 08/14] bpf: Report non-sleepable kfunc programs accurately

[Eduard Zingerman <eddyz87@gmail.com>]

On Sun, 2026-08-16 at 03:57 +0200, Kumar Kartikeya Dwivedi wrote:

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

...

> diff --git a/kernel/bpf/diagnostics.c b/kernel/bpf/diagnostics.c
> index 2c475174a640..df9259fa0ea7 100644
> --- a/kernel/bpf/diagnostics.c
> +++ b/kernel/bpf/diagnostics.c
> @@ -1083,7 +1083,9 @@ void bpf_diag_ctx_forbidden(struct bpf_verifier_env *env, u32 insn_idx,
>  	const char *constraint, *context;
>  	u32 depth;
>  
> -	if (env->cur_state->active_rcu_locks)
> +	if (!env->cur_state->in_sleepable)
> +		ctx_kind = BPF_DIAG_CONTEXT_NONE;

Let's do what bot suggests and rely on the final 'else' instead of
adding this branch.

> +	else if (env->cur_state->active_rcu_locks)
>  		ctx_kind = BPF_DIAG_CONTEXT_RCU;
>  	else if (env->cur_state->active_preempt_locks)
>  		ctx_kind = BPF_DIAG_CONTEXT_PREEMPT;
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index da2ec0655b17..3de9e4f617b6 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -9912,7 +9912,7 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
>  				sub_name, non_sleepable_context_description(env));
>  			operation = bpf_diag_fmt(env, "sleepable global function %s()", sub_name);
>  			bpf_diag_ctx_forbidden(env, *insn_idx, operation,
> -				"Move the call outside the critical section, or use a non-sleepable function.");
> +				"Call the function from a sleepable program outside any critical section, or use a non-sleepable function.");
>  			return -EINVAL;
>  		}
>  
> @@ -10731,6 +10731,8 @@ static inline bool in_sleepable_context(struct bpf_verifier_env *env)
>  
>  static const char *non_sleepable_context_description(struct bpf_verifier_env *env)
>  {
> +	if (!in_sleepable(env))
> +		return "non-sleepable prog";

Let's drop this hunk and rely on the `return "non-sleepable context"`.
Not sure if we need to change 'prog' to 'context', tbh.

>  	if (env->cur_state->active_rcu_locks)
>  		return "rcu_read_lock region";
>  	if (env->cur_state->active_preempt_locks)
> @@ -10739,7 +10741,7 @@ static const char *non_sleepable_context_description(struct bpf_verifier_env *en
>  		return "IRQ-disabled region";
>  	if (env->cur_state->active_locks)
>  		return "lock region";
> -	return "non-sleepable prog";
> +	return "non-sleepable context";
>  }
>  
>  static int release_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,

...