[media] videobuf2: Add support for file access mode flags for DMABUF exporting

Currently it is not possible for userspace to map a DMABUF exported buffer
with write permissions. This patch allows to also pass O_RDONLY/O_RDWR when
exporting the buffer, so that userspace may map it with write permissions.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

2 files changed, 6 insertions, 6 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index b19b306..57ba131 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1824,8 +1824,8 @@ int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
 		return -EINVAL;
 	}
 
-	if (eb->flags & ~O_CLOEXEC) {
-		dprintk(1, "Queue does support only O_CLOEXEC flag\n");
+	if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
+		dprintk(1, "Queue does support only O_CLOEXEC and access mode flags\n");
 		return -EINVAL;
 	}
 
@@ -1848,14 +1848,14 @@ int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
 
 	vb_plane = &vb->planes[eb->plane];
 
-	dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv);
+	dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
 	if (IS_ERR_OR_NULL(dbuf)) {
 		dprintk(1, "Failed to export buffer %d, plane %d\n",
 			eb->index, eb->plane);
 		return -EINVAL;
 	}
 
-	ret = dma_buf_fd(dbuf, eb->flags);
+	ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
 	if (ret < 0) {
 		dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
 			eb->index, eb->plane, ret);
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 646f08f..33d3871d 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -393,7 +393,7 @@ static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf)
 	return sgt;
 }
 
-static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv)
+static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 	struct dma_buf *dbuf;
@@ -404,7 +404,7 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv)
 	if (WARN_ON(!buf->sgt_base))
 		return NULL;
 
-	dbuf = dma_buf_export(buf, &vb2_dc_dmabuf_ops, buf->size, 0);
+	dbuf = dma_buf_export(buf, &vb2_dc_dmabuf_ops, buf->size, flags);
 	if (IS_ERR(dbuf))
 		return NULL;