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 <iws@ovro.caltech.edu>
Signed-off-by: Li Yang <leoli@freescale.com>
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 @@
{
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 @@
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 @@
/* 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;
}
/**