[PATCH v0 25/42] arch/um: Check notifier registration return value

[Borislav Petkov]

From: Borislav Petkov <bp@xxxxxxx>

Avoid homegrown notifier registration checks.

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: linux-um@xxxxxxxxxxxxxxxxxxx
---
 arch/um/drivers/mconsole_kern.c | 6 ++++--
 arch/um/kernel/um_arch.c        | 5 +++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 6ead1e240457..ceea940c0aa0 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -856,8 +856,10 @@ static struct notifier_block panic_exit_notifier = {
 
 static int add_notifier(void)
 {
-	atomic_notifier_chain_register(&panic_notifier_list,
-			&panic_exit_notifier);
+	if (atomic_notifier_chain_register(&panic_notifier_list,
+					   &panic_exit_notifier))
+		pr_warn("UM console panic notifier already registered\n");
+
 	return 0;
 }
 
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 54447690de11..6c0e562ff0b7 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -255,8 +255,9 @@ static struct notifier_block panic_exit_notifier = {
 
 void uml_finishsetup(void)
 {
-	atomic_notifier_chain_register(&panic_notifier_list,
-				       &panic_exit_notifier);
+	if (atomic_notifier_chain_register(&panic_notifier_list,
+					   &panic_exit_notifier))
+		pr_warn("UM panic notifier already registered\n");
 
 	uml_postsetup();
 
-- 
2.29.2