[PATCH 3.13.y-ckt 52/90] dmaengine: edma: fix memory leak when terminating running transfers
Kamal Mostafa
kamal at canonical.com
Tue May 5 20:54:24 UTC 2015
3.13.11-ckt20 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Petr Kulhavy <petr at barix.com>
commit 5ca9e7ce6eebec53362ff779264143860ccf68cd upstream.
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 at barix.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
CC: <linux-omap at vger.kernel.org>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/dma/edma.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 037443c..52a3884 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -219,6 +219,12 @@ static int edma_terminate_all(struct edma_chan *echan)
* echan->edesc is NULL and exit.)
*/
if (echan->edesc) {
+ /*
+ * 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);
}
--
1.9.1
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