This patch removes a reference to alloc_ctx from an instance of a DMA contiguous buffer. It helps to avoid a risk of a dangling pointer if the context is released while the buffer is still valid. Moreover it removes one dereference step while accessing a device structure.
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Acked-by: Hans Verkuil hans.verkuil@cisco.com --- drivers/media/v4l2-core/videobuf2-dma-contig.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index a05784f..20c95da 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -23,7 +23,7 @@ struct vb2_dc_conf { };
struct vb2_dc_buf { - struct vb2_dc_conf *conf; + struct device *dev; void *vaddr; dma_addr_t dma_addr; unsigned long size; @@ -37,22 +37,21 @@ static void vb2_dc_put(void *buf_priv); static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size) { struct vb2_dc_conf *conf = alloc_ctx; + struct device *dev = conf->dev; struct vb2_dc_buf *buf;
buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) return ERR_PTR(-ENOMEM);
- buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->dma_addr, - GFP_KERNEL); + buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL); if (!buf->vaddr) { - dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n", - size); + dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size); kfree(buf); return ERR_PTR(-ENOMEM); }
- buf->conf = conf; + buf->dev = dev; buf->size = size;
buf->handler.refcount = &buf->refcount; @@ -69,7 +68,7 @@ static void vb2_dc_put(void *buf_priv) struct vb2_dc_buf *buf = buf_priv;
if (atomic_dec_and_test(&buf->refcount)) { - dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr, + dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr); kfree(buf); }