workqueue: make workqueue->name[] fixed len
Currently workqueue->name[] is of flexible length. We want to use the
flexible field for something more useful and there isn't much benefit
in allowing arbitrary name length anyway. Make it fixed len capping
at 24 bytes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 32b4744..c8c5838 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -101,6 +101,8 @@
*/
RESCUER_NICE_LEVEL = -20,
HIGHPRI_NICE_LEVEL = -20,
+
+ WQ_NAME_LEN = 24,
};
/*
@@ -252,7 +254,7 @@
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
- char name[]; /* I: workqueue name */
+ char name[WQ_NAME_LEN]; /* I: workqueue name */
};
static struct kmem_cache *pwq_cache;
@@ -3757,17 +3759,12 @@
struct lock_class_key *key,
const char *lock_name, ...)
{
- va_list args, args1;
+ va_list args;
struct workqueue_struct *wq;
struct pool_workqueue *pwq;
- size_t namelen;
- /* determine namelen, allocate wq and format name */
- va_start(args, lock_name);
- va_copy(args1, args);
- namelen = vsnprintf(NULL, 0, fmt, args) + 1;
-
- wq = kzalloc(sizeof(*wq) + namelen, GFP_KERNEL);
+ /* allocate wq and format name */
+ wq = kzalloc(sizeof(*wq), GFP_KERNEL);
if (!wq)
return NULL;
@@ -3777,9 +3774,9 @@
goto err_free_wq;
}
- vsnprintf(wq->name, namelen, fmt, args1);
+ va_start(args, lock_name);
+ vsnprintf(wq->name, sizeof(wq->name), fmt, args);
va_end(args);
- va_end(args1);
max_active = max_active ?: WQ_DFL_ACTIVE;
max_active = wq_clamp_max_active(max_active, flags, wq->name);