Re: [PATCH] dma-buf: handle testing kthreads creation failure

2024-05-22 Thread T.J. Mercier 
On Wed, May 22, 2024 at 5:24 AM Fedor Pchelkin  wrote:
>
> kthread creation may possibly fail inside race_signal_callback(). In
> such case stop the already started threads and return with error code.
>
> Found by Linux Verification Center (linuxtesting.org).
>
> Fixes: 2989f6451084 ("dma-buf: Add selftests for dma-fence")
> Cc: sta...@vger.kernel.org
> Signed-off-by: Fedor Pchelkin 
> ---
>  drivers/dma-buf/st-dma-fence.c | 6 ++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c
> index b7c6f7ea9e0c..ab1ec4631578 100644
> --- a/drivers/dma-buf/st-dma-fence.c
> +++ b/drivers/dma-buf/st-dma-fence.c
> @@ -540,6 +540,12 @@ static int race_signal_callback(void *arg)
> t[i].before = pass;
> t[i].task = kthread_run(thread_signal_callback, &t[i],
> "dma-fence:%d", i);
> +   if (IS_ERR(t[i].task)) {
> +   ret = PTR_ERR(t[i].task);
> +   while (--i >= 0)
> +   kthread_stop(t[i].task);

This looks like it needs to be kthread_stop_put since get_task_struct
was called for previous successful kthread_run calls.

> +   return ret;
> +   }
> get_task_struct(t[i].task);
> }
>
> --
> 2.39.2
>

[PATCH] dma-buf: handle testing kthreads creation failure

2024-05-22 Thread Fedor Pchelkin 
kthread creation may possibly fail inside race_signal_callback(). In
such case stop the already started threads and return with error code.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 2989f6451084 ("dma-buf: Add selftests for dma-fence")
Cc: sta...@vger.kernel.org
Signed-off-by: Fedor Pchelkin 
---
 drivers/dma-buf/st-dma-fence.c | 6 ++
 1 file changed, 6 insertions(+)

diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c
index b7c6f7ea9e0c..ab1ec4631578 100644
--- a/drivers/dma-buf/st-dma-fence.c
+++ b/drivers/dma-buf/st-dma-fence.c
@@ -540,6 +540,12 @@ static int race_signal_callback(void *arg)
t[i].before = pass;
t[i].task = kthread_run(thread_signal_callback, &t[i],
"dma-fence:%d", i);
+   if (IS_ERR(t[i].task)) {
+   ret = PTR_ERR(t[i].task);
+   while (--i >= 0)
+   kthread_stop(t[i].task);
+   return ret;
+   }
get_task_struct(t[i].task);
}
 
-- 
2.39.2