[3/9] kmemleak: correctly check for kthreads

Message ID 20190814104131.20190-4-mark.rutland@arm.com
State New
Headers show
Series
  • kthread detection cleanup
Related show

Commit Message

Mark Rutland Aug. 14, 2019, 10:41 a.m.
In general, a non-NULL current->mm doesn't imply that current is a
kthread, as kthreads can install an mm via use_mm(), and so it's
preferable to use is_kthread() to determine whether a thread is a
kthread.

For consistency, let's use is_kthread() here.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
---
 mm/kmemleak.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.11.0

Comments

Catalin Marinas Aug. 14, 2019, 4:39 p.m. | #1
On Wed, Aug 14, 2019 at 11:41:25AM +0100, Mark Rutland wrote:
> In general, a non-NULL current->mm doesn't imply that current is a

> kthread, as kthreads can install an mm via use_mm(), and so it's

> preferable to use is_kthread() to determine whether a thread is a

> kthread.

> 

> For consistency, let's use is_kthread() here.

> 

> Signed-off-by: Mark Rutland <mark.rutland@arm.com>

> Cc: Catalin Marinas <catalin.marinas@arm.com>

> Cc: Ingo Molnar <mingo@kernel.org>

> Cc: Peter Zijlstra <peterz@infradead.org>

> ---

>  mm/kmemleak.c | 6 +++---

>  1 file changed, 3 insertions(+), 3 deletions(-)


Acked-by: Catalin Marinas <catalin.marinas@arm.com>


> index 6e9e8cca663e..42ea3c14b577 100644

> --- a/mm/kmemleak.c

> +++ b/mm/kmemleak.c

> @@ -1290,10 +1290,10 @@ static int scan_should_stop(void)

>  	 * This function may be called from either process or kthread context,

>  	 * hence the need to check for both stop conditions.

>  	 */

> -	if (current->mm)

> -		return signal_pending(current);

> -	else

> +	if (is_kthread(current))

>  		return kthread_should_stop();

> +	else

> +		return signal_pending(current);


While you are at it, you can drop the 'else' as well (occasionally
checkpatch complains about 'else' after return).

Thanks.

-- 
Catalin

Patch

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 6e9e8cca663e..42ea3c14b577 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1290,10 +1290,10 @@  static int scan_should_stop(void)
 	 * This function may be called from either process or kthread context,
 	 * hence the need to check for both stop conditions.
 	 */
-	if (current->mm)
-		return signal_pending(current);
-	else
+	if (is_kthread(current))
 		return kthread_should_stop();
+	else
+		return signal_pending(current);
 
 	return 0;
 }