[PATCH bpf-next v4 2/7] bpf: consolidate sleepable checks in check_helper_call()

[Puranjay Mohan <puranjay@kernel.org>]

check_helper_call() prints the error message for every
env->cur_state->active* element when calling a sleepable helper.
Consolidate all of them into a single print statement.

The check for env->cur_state->active_locks was not part of the removed
print statements and will not be triggered with the consolidated print
as well because it is checked in do_check() before check_helper_call()
is even reached.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 kernel/bpf/verifier.c | 40 ++++++++++++++++++----------------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index af18cda06dc1..ddfb88b8ddd2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11581,6 +11581,19 @@ static inline bool in_sleepable_context(struct bpf_verifier_env *env)
 	       in_sleepable(env);
 }
 
+static const char *non_sleepable_context_description(struct bpf_verifier_env *env)
+{
+	if (env->cur_state->active_rcu_locks)
+		return "rcu_read_lock region";
+	if (env->cur_state->active_preempt_locks)
+		return "non-preemptible region";
+	if (env->cur_state->active_irq_id)
+		return "IRQ-disabled region";
+	if (env->cur_state->active_locks)
+		return "lock region";
+	return "non-sleepable context";
+}
+
 static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
 			     int *insn_idx_p)
 {
@@ -11641,28 +11654,11 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 		return err;
 	}
 
-	if (env->cur_state->active_rcu_locks) {
-		if (fn->might_sleep) {
-			verbose(env, "sleepable helper %s#%d in rcu_read_lock region\n",
-				func_id_name(func_id), func_id);
-			return -EINVAL;
-		}
-	}
-
-	if (env->cur_state->active_preempt_locks) {
-		if (fn->might_sleep) {
-			verbose(env, "sleepable helper %s#%d in non-preemptible region\n",
-				func_id_name(func_id), func_id);
-			return -EINVAL;
-		}
-	}
-
-	if (env->cur_state->active_irq_id) {
-		if (fn->might_sleep) {
-			verbose(env, "sleepable helper %s#%d in IRQ-disabled region\n",
-				func_id_name(func_id), func_id);
-			return -EINVAL;
-		}
+	if (fn->might_sleep && !in_sleepable_context(env)) {
+		verbose(env, "sleepable helper %s#%d in %s\n",
+			func_id_name(func_id), func_id,
+			non_sleepable_context_description(env));
+		return -EINVAL;
 	}
 
 	/* Track non-sleepable context for helpers. */
-- 
2.47.3