kmemleak: Do no create the clean-up thread during kmemleak_disable()

The kmemleak_disable() function could be called from various contexts
including IRQ. It creates a clean-up thread but the kthread_create()
function has restrictions on which contexts it can be called from,
mainly because of the kthread_create_lock. The patch changes the
kmemleak clean-up thread to a workqueue.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Eric Paris <eparis@redhat.com>
This commit is contained in:
Catalin Marinas 2009-09-07 10:14:42 +01:00
parent 43ed5d6ee0
commit 179a8100e1

View file

@ -92,6 +92,7 @@
#include <linux/string.h>
#include <linux/nodemask.h>
#include <linux/mm.h>
#include <linux/workqueue.h>
#include <asm/sections.h>
#include <asm/processor.h>
@ -1499,7 +1500,7 @@ static const struct file_operations kmemleak_fops = {
* Perform the freeing of the kmemleak internal objects after waiting for any
* current memory scan to complete.
*/
static int kmemleak_cleanup_thread(void *arg)
static void kmemleak_do_cleanup(struct work_struct *work)
{
struct kmemleak_object *object;
@ -1511,22 +1512,9 @@ static int kmemleak_cleanup_thread(void *arg)
delete_object_full(object->pointer);
rcu_read_unlock();
mutex_unlock(&scan_mutex);
return 0;
}
/*
* Start the clean-up thread.
*/
static void kmemleak_cleanup(void)
{
struct task_struct *cleanup_thread;
cleanup_thread = kthread_run(kmemleak_cleanup_thread, NULL,
"kmemleak-clean");
if (IS_ERR(cleanup_thread))
pr_warning("Failed to create the clean-up thread\n");
}
static DECLARE_WORK(cleanup_work, kmemleak_do_cleanup);
/*
* Disable kmemleak. No memory allocation/freeing will be traced once this
@ -1544,7 +1532,7 @@ static void kmemleak_disable(void)
/* check whether it is too early for a kernel thread */
if (atomic_read(&kmemleak_initialized))
kmemleak_cleanup();
schedule_work(&cleanup_work);
pr_info("Kernel memory leak detector disabled\n");
}
@ -1640,7 +1628,7 @@ static int __init kmemleak_late_init(void)
* after setting kmemleak_initialized and we may end up with
* two clean-up threads but serialized by scan_mutex.
*/
kmemleak_cleanup();
schedule_work(&cleanup_work);
return -ENOMEM;
}