media: videobuf2: Fix IS_ERR checking in vb2_dc_put_userptr()

In order to avoid error pointers from frame_vector_pages(), we could
use IS_ERR() to check the return value to fix this. This checking
operation could make sure that vector contains pages.

Signed-off-by: Ma Ke <make_ruc2021@163.com>
Acked-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index 2fa455d4a0480e95fd8c42b3e00db321370d396b..3d4fd4ef53107c6519442d24d11e7c449b0fa8ba 100644 (file)
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -542,13 +542,14 @@ static void vb2_dc_put_userptr(void *buf_priv)
                 */
                dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
                                  DMA_ATTR_SKIP_CPU_SYNC);
-               pages = frame_vector_pages(buf->vec);
-               /* sgt should exist only if vector contains pages... */
-               BUG_ON(IS_ERR(pages));
                if (buf->dma_dir == DMA_FROM_DEVICE ||
-                   buf->dma_dir == DMA_BIDIRECTIONAL)
-                       for (i = 0; i < frame_vector_count(buf->vec); i++)
-                               set_page_dirty_lock(pages[i]);
+                               buf->dma_dir == DMA_BIDIRECTIONAL) {
+                       pages = frame_vector_pages(buf->vec);
+                       /* sgt should exist only if vector contains pages... */
+                       if (!WARN_ON_ONCE(IS_ERR(pages)))
+                               for (i = 0; i < frame_vector_count(buf->vec); i++)
+                                       set_page_dirty_lock(pages[i]);
+               }
                sg_free_table(sgt);
                kfree(sgt);
        } else {