[PATCH 1/1] platform/x86: surface3-wmi: Balance locking on error path

From: Andy Shevchenko
Date: Wed Dec 14 2016 - 20:30:41 EST


There is a possibility that lock will be left acquired.
Consolidate error path under out_free_unlock label.

Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/surface3-wmi.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/platform/x86/surface3-wmi.c b/drivers/platform/x86/surface3-wmi.c
index 5553b2b85e0a..ed7a3b77a0cc 100644
--- a/drivers/platform/x86/surface3-wmi.c
+++ b/drivers/platform/x86/surface3-wmi.c
@@ -60,10 +60,10 @@ static DEFINE_MUTEX(s3_wmi_lock);

static int s3_wmi_query_block(const char *guid, int instance, int *ret)
{
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_status status;
union acpi_object *obj;
-
- struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ int error = 0;

mutex_lock(&s3_wmi_lock);
status = wmi_query_block(guid, instance, &output);
@@ -77,13 +77,14 @@ static int s3_wmi_query_block(const char *guid, int instance, int *ret)
obj->type == ACPI_TYPE_BUFFER ?
obj->buffer.length : 0);
}
- kfree(obj);
- return -EINVAL;
+ error = -EINVAL;
+ goto out_free_unlock;
}
*ret = obj->integer.value;
+out_free_unlock:
kfree(obj);
mutex_unlock(&s3_wmi_lock);
- return 0;
+ return error;
}

static inline int s3_wmi_query_lid(int *ret)
--
2.11.0