Commit 5ca9e7ce authored Mar 27, 2015 by Petr Kulhavy Committed by Vinod Koul Mar 30, 2015

dmaengine: edma: fix memory leak when terminating running transfers



If edma_terminate_all() was called while a transfer was running (i.e. after
edma_execute() but before edma_callback()) the echan->edesc was not freed.

This was due to the fact that a running transfer is on none of the
vchan lists: desc_submitted, desc_issued, desc_completed (edma_execute()
removes it from the desc_issued list), so the vchan_dma_desc_free_list()
called at the end of edma_terminate_all() didn't find it and didn't free it.

This bug was found on an AM1808 based hardware (very similar to da850evm,
however using the second MMC/SD controller), where intense operations on the SD
card wasted the device 128MB RAM within a couple of days.

Peter Ujfalusi:
The issue is even more severe since it affects cyclic (audio) transfers as
well. In this case starting/stopping audio will results memory leak.

Signed-off-by: Petr Kulhavy <petr@barix.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
CC: <stable@vger.kernel.org>
CC: <linux-omap@vger.kernel.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

parent ca766839

drivers/dma/edma.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -260,6 +260,13 @@ static int edma_terminate_all(struct dma_chan *chan)
		*/
		if (echan->edesc) {
		int cyclic = echan->edesc->cyclic;

		/*
		* free the running request descriptor
		* since it is not in any of the vdesc lists
		*/
		edma_desc_free(&echan->edesc->vdesc);

		echan->edesc = NULL;
		edma_stop(echan->ch_num);
		/* Move the cyclic channel back to default queue */