On 2025/6/23 23:06, Dan Carpenter wrote:
On Mon, Jun 23, 2025 at 06:47:05PM +0800, Su Hui wrote:
There are three cleanups for vmcore_add_device_dump(). Adjust data_size's
type from 'size_t' to 'unsigned int' for the consistency of data->size.
Return -ENOMEM directly rather than goto the label to simplify the code.
Using scoped_guard() to simplify the lock/unlock code.
Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
---
fs/proc/vmcore.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 10d01eb09c43..9ac2863c68d8 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -1477,7 +1477,7 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
{
struct vmcoredd_node *dump;
void *buf = NULL;
- size_t data_size;
+ unsigned int data_size;
int ret;
This was in reverse Christmas tree order before. Move the data_size
declaration up a line.
long long_variable_name;
medium variable_name;
short name;
Got it, and this 'usgined int' will be removed because of 'size_t' can
avoid overflow in some case.
if (vmcoredd_disabled) {
@@ -1490,10 +1490,8 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
return -EINVAL;
dump = vzalloc(sizeof(*dump));
- if (!dump) {
- ret = -ENOMEM;
- goto out_err;
- }
+ if (!dump)
+ return -ENOMEM;
/* Keep size of the buffer page aligned so that it can be mmaped */
data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
@@ -1519,21 +1517,18 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
dump->size = data_size;
/* Add the dump to driver sysfs list and update the elfcore hdr */
- mutex_lock(&vmcore_mutex);
- if (vmcore_opened)
- pr_warn_once("Unexpected adding of device dump\n");
- if (vmcore_open) {
- ret = -EBUSY;
- goto unlock;
- }
-
- list_add_tail(&dump->list, &vmcoredd_list);
- vmcoredd_update_size(data_size);
- mutex_unlock(&vmcore_mutex);
- return 0;
+ scoped_guard(mutex, &vmcore_mutex) {
+ if (vmcore_opened)
+ pr_warn_once("Unexpected adding of device dump\n");
+ if (vmcore_open) {
+ ret = -EBUSY;
+ goto out_err;
+ }
-unlock:
- mutex_unlock(&vmcore_mutex);
+ list_add_tail(&dump->list, &vmcoredd_list);
+ vmcoredd_update_size(data_size);
+ return 0;
Please, move this "return 0;" out of the scoped_guard(). Otherwise
it's not obvious that we return zero on the success path.
Yes, it's better. Will update in v2 patch.
Thanks again!
Regards,
Su Hui
