[PATCH] dma-buf: fix order of trace and fput

[PATCH] dma-buf: fix order of trace and fput

[Christian König]

Dropping the last reference to the DMA-buf and then accessing the name
for tracing can't work correctly.

Only compile tested!

Signed-off-by: Christian König <christian.koenig@amd.com>
Fixed: 281a22631423 ("dma-buf: add some tracepoints to debug.")
---
 drivers/dma-buf/dma-buf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 11711874a325..3a9d5113b98c 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -845,9 +845,8 @@ void dma_buf_put(struct dma_buf *dmabuf)
 	if (WARN_ON(!dmabuf || !dmabuf->file))
 		return;
 
-	fput(dmabuf->file);
-
 	DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
+	fput(dmabuf->file);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_put, "DMA_BUF");
 
-- 
2.43.0

Re: [PATCH] dma-buf: fix order of trace and fput

[Andi Shyti]

Hi Christian,

> @@ -845,9 +845,8 @@ void dma_buf_put(struct dma_buf *dmabuf)
>  	if (WARN_ON(!dmabuf || !dmabuf->file))
>  		return;
>  
> -	fput(dmabuf->file);
> -
>  	DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
> +	fput(dmabuf->file);

funny, I just found out I sent the exact same patch, just few
minutes later :-) [*]

Andi

>  }

[*] https://lore.kernel.org/all/20260408123916.2604101-2-andi.shyti@kernel.org/

Re: [PATCH] dma-buf: fix order of trace and fput

[Christian König]

On 4/9/26 14:38, Andi Shyti wrote:
> Hi Christian,
> 
>> @@ -845,9 +845,8 @@ void dma_buf_put(struct dma_buf *dmabuf)
>>  	if (WARN_ON(!dmabuf || !dmabuf->file))
>>  		return;
>>  
>> -	fput(dmabuf->file);
>> -
>>  	DMA_BUF_TRACE(trace_dma_buf_put, dmabuf);
>> +	fput(dmabuf->file);
> 
> funny, I just found out I sent the exact same patch, just few
> minutes later :-) [*]

I liked your patch better since it has more accurate tags.

Just reviewed and pushed that one to drm-misc-fixes, should land upstream by the end of the week.

Regards,
Christian.

> 
> Andi
> 
>>  }
> 
> [*] https://lore.kernel.org/all/20260408123916.2604101-2-andi.shyti@kernel.org/