2017-06-09 23:18:42

by Alexey Khoroshilov

Subject: [PATCH] goldfish_pipe: allocate memory with GFP_ATOMIC in spinlock context

get_free_pipe_id_locked() is called with spinlock held, so
the patch replaces GFP_KERNEL with GFP_ATOMIC to avoid
sleeping in atomic spinlock context.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
drivers/platform/goldfish/goldfish_pipe.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 2de1e603bd2b..5f3672153b12 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -704,7 +704,7 @@ static int get_free_pipe_id_locked(struct goldfish_pipe_dev *dev)
/* Reallocate the array */
u32 new_capacity = 2 * dev->pipes_capacity;
struct goldfish_pipe **pipes =
- kcalloc(new_capacity, sizeof(*pipes), GFP_KERNEL);
+ kcalloc(new_capacity, sizeof(*pipes), GFP_ATOMIC);
if (!pipes)
return -ENOMEM;
memcpy(pipes, dev->pipes, sizeof(*pipes) * dev->pipes_capacity);
--
2.7.4

2017-06-13 14:02:23

by Greg Kroah-Hartman

Subject: Re: [PATCH] goldfish_pipe: allocate memory with GFP_ATOMIC in spinlock context

On Sat, Jun 10, 2017 at 02:18:26AM +0300, Alexey Khoroshilov wrote:
> get_free_pipe_id_locked() is called with spinlock held, so
> the patch replaces GFP_KERNEL with GFP_ATOMIC to avoid
> sleeping in atomic spinlock context.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> ---
> drivers/platform/goldfish/goldfish_pipe.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

This is already in my tree, why resend it?

thanks,

greg k-h