From 2e077f8e8337e52eef3c39c24c31e103b11a0326 Mon Sep 17 00:00:00 2001 From: Ira Snyder Date: Fri, 15 May 2009 09:59:46 -0700 Subject: [PATCH] fsldma: fix memory leak on error path in fsl_dma_prep_memcpy() When preparing a memcpy operation, if the kernel fails to allocate memory for a link descriptor after the first link descriptor has already been allocated, then some memory will never be released. Fix the problem by walking the list of allocated descriptors backwards, and freeing the allocated descriptors back into the DMA pool. Signed-off-by: Ira W. Snyder Signed-off-by: Li Yang --- drivers/dma/fsldma.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index ff9194d..1578310 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -462,8 +462,8 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( { struct fsl_dma_chan *fsl_chan; struct fsl_desc_sw *first = NULL, *prev = NULL, *new; + struct list_head *list; size_t copy; - LIST_HEAD(link_chain); if (!chan) return NULL; @@ -480,7 +480,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( if (!new) { dev_err(fsl_chan->dev, "No free memory for link descriptor\n"); - return NULL; + goto fail; } #ifdef FSL_DMA_LD_DEBUG dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new); @@ -515,7 +515,19 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( /* Set End-of-link to the last link descriptor of new list*/ set_ld_eol(fsl_chan, new); - return first ? &first->async_tx : NULL; + return &first->async_tx; + +fail: + if (!first) + return NULL; + + list = &first->async_tx.tx_list; + list_for_each_entry_safe_reverse(new, prev, list, node) { + list_del(&new->node); + dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys); + } + + return NULL; } /** -- 2.7.4