Re: [PATCH] dma-buf: fix compare in WARN_ON_ONCE

[Tvrtko Ursulin]

On 05/06/2025 09:53, Christian König wrote:

Smatch pointed out this trivial typo:
        drivers/dma-buf/dma-buf.c:1123 dma_buf_map_attachment()
        warn: passing positive error code '16' to 'ERR_PTR'

drivers/dma-buf/dma-buf.c
     1113         dma_resv_assert_held(attach->dmabuf->resv);
     1114
     1115         if (dma_buf_pin_on_map(attach)) {
     1116                 ret = attach->dmabuf->ops->pin(attach);
     1117                 /*
     1118                  * Catch exporters making buffers inaccessible even 
when
     1119                  * attachments preventing that exist.
     1120                  */
     1121                 WARN_ON_ONCE(ret == EBUSY);
                                              ^^^^^
This was probably intended to be -EBUSY?

     1122                 if (ret)
--> 1123                         return ERR_PTR(ret);
                                                 ^^^
Otherwise we will eventually crash.

     1124         }
     1125
     1126         sg_table = attach->dmabuf->ops->map_dma_buf(attach, 
direction);
     1127         if (!sg_table)
     1128                 sg_table = ERR_PTR(-ENOMEM);
     1129         if (IS_ERR(sg_table))
     1130                 goto error_unpin;
     1131

Signed-off-by: Christian König <christian.koe...@amd.com>
---
  drivers/dma-buf/dma-buf.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 0c48d41dd5eb..451714008e8a 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1060,7 +1060,7 @@ struct sg_table *dma_buf_map_attachment(struct 
dma_buf_attachment *attach,
                 * Catch exporters making buffers inaccessible even when
                 * attachments preventing that exist.
                 */
-               WARN_ON_ONCE(ret == EBUSY);
+               WARN_ON_ONCE(ret == -EBUSY);
                if (ret)
                        return ERR_PTR(ret);
        }

Thread bump FTW ;)

Reviewed-by: Tvrtko Ursulin <tvrtko.ursu...@igalia.com>

Regards,

Tvrtko