Commit dfe6625d authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Alexei Starovoitov
Browse files

bpf: introduce in_sleepable() helper 



No code change, but it'll allow to have only one place to change
everything when we add in_sleepable in cur_state.

Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240221-hid-bpf-sleepable-v3-2-1fb378ca6301@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 55bad79e

kernel/bpf/verifier.c

+11 −6
Original line number Diff line number Diff line
@@ -5255,6 +5255,11 @@ static int map_kptr_match_type(struct bpf_verifier_env *env, 
	return -EINVAL;

}









static bool in_sleepable(struct bpf_verifier_env *env)









{









	return env->prog->aux->sleepable;









}

















/* The non-sleepable programs and sleepable programs with explicit bpf_rcu_read_lock()









 * can dereference RCU protected pointers and result is PTR_TRUSTED.









 */








@@ -5262,7 +5267,7 @@ static bool in_rcu_cs(struct bpf_verifier_env *env)







{









	return env->cur_state->active_rcu_lock ||









	       env->cur_state->active_lock.ptr ||









	       !env->prog->aux->sleepable;









	       !in_sleepable(env);









}

















/* Once GCC supports btf_type_tag the following mechanism will be replaced with tag check */








@@ -10164,7 +10169,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn







		return -EINVAL;









	}

















	if (!env->prog->aux->sleepable && fn->might_sleep) {









	if (!in_sleepable(env) && fn->might_sleep) {









		verbose(env, "helper call might sleep in a non-sleepable prog\n");









		return -EINVAL;









	}








@@ -10194,7 +10199,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn







			return -EINVAL;









		}

















		if (env->prog->aux->sleepable && is_storage_get_function(func_id))









		if (in_sleepable(env) && is_storage_get_function(func_id))









			env->insn_aux_data[insn_idx].storage_get_func_atomic = true;









	}
















@@ -11535,7 +11540,7 @@ static bool check_css_task_iter_allowlist(struct bpf_verifier_env *env)







			return true;









		fallthrough;









	default:









		return env->prog->aux->sleepable;









		return in_sleepable(env);









	}









}
















@@ -12056,7 +12061,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,







	}

















	sleepable = is_kfunc_sleepable(&meta);









	if (sleepable && !env->prog->aux->sleepable) {









	if (sleepable && !in_sleepable(env)) {









		verbose(env, "program must be sleepable to call sleepable kfunc %s\n", func_name);









		return -EACCES;









	}








@@ -19669,7 +19674,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)







		}

















		if (is_storage_get_function(insn->imm)) {









			if (!env->prog->aux->sleepable ||









			if (!in_sleepable(env) ||









			    env->insn_aux_data[i + delta].storage_get_func_atomic)









				insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_ATOMIC);









			else