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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/media/video/videobuf2-dma-contig.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
index a05784f..20c95da 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/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);
}
--
1.7.9.5
--
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