From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
dev_pm_get_subsys_data() has below 2 issues under condition
(@dev->power.subsys_data != NULL):
- it will do unnecessary kzalloc() and kfree().
- it will return -ENOMEM if the kzalloc() fails, that is wrong
since the kzalloc() is not needed.
Fixed by not doing kzalloc() and returning 0 for the condition.
Fixes: ef27bed1870d ("PM: Reference counting of power.subsys_data")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
drivers/base/power/common.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index 8c34ae1cd8d5..13cb1f2a06e7 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -26,6 +26,14 @@ int dev_pm_get_subsys_data(struct device *dev)
{
struct pm_subsys_data *psd;
+ spin_lock_irq(&dev->power.lock);
+ if (dev->power.subsys_data) {
+ dev->power.subsys_data->refcount++;
+ spin_unlock_irq(&dev->power.lock);
+ return 0;
+ }
+ spin_unlock_irq(&dev->power.lock);
+
psd = kzalloc(sizeof(*psd), GFP_KERNEL);
if (!psd)
return -ENOMEM;
---
base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
change-id: 20241010-fix_dev_pm_get_subsys_data-2478bb200fde
Best regards,
--
Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
