[PATCH] PM: hibernate: add sanity check on power_kobj

From: Abel Wu <abel.w@icloud.com>
To: rjw@rjwysocki.net, pavel@ucw.cz
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
	hewenliang4@huawei.com, wuyun.wu@huawei.com,
	Abel Wu <abel.w@icloud.com>
Subject: [PATCH] PM: hibernate: add sanity check on power_kobj
Date: Mon,  1 Feb 2021 02:50:41 -0500	[thread overview]
Message-ID: <20210201075041.1201-1-abel.w@icloud.com> (raw)

The @power_kobj is initialized in pm_init() which is the same
initcall level as pm_disk_init(). Although this dependency is
guaranteed based on the current initcall serial execution model,
it would still be better do a cost-less sanity check to avoid
oops once the dependency is broken.

Signed-off-by: Abel Wu <abel.w@icloud.com>
---
 kernel/power/hibernate.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index da0b41914177..060089cc261d 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1262,6 +1262,9 @@ static const struct attribute_group attr_group = {
 
 static int __init pm_disk_init(void)
 {
+	if (!power_kobj)
+		return -EINVAL;
+
 	return sysfs_create_group(power_kobj, &attr_group);
 }
 
-- 
2.27.0

