From 72f86bffbc59de76458cb8c3981df12e059b71fc Mon Sep 17 00:00:00 2001 From: Tomasz Stanislawski Date: Thu, 14 Jun 2012 10:37:40 -0300 Subject: [PATCH] [media] v4l: vb2-dma-contig: remove reference of alloc_ctx from a buffer 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 Signed-off-by: Kyungmin Park Acked-by: Laurent Pinchart Acked-by: Hans Verkuil Tested-by: Mauro Carvalho Chehab Signed-off-by: Mauro Carvalho Chehab --- 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); } -- 2.7.4