fsldma: fix memory leak on error path in fsl_dma_prep_memcpy() (2e077f8e) · Commits · 戴 / test

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 <iws@ovro.caltech.edu> Signed-off-by:

Li Yang <leoli@freescale.com>

drivers/dma/fsldma.c

+15 −3

Original line number	Diff line number	Diff line
		@@ -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;
		}

		/**

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