Commit a9df21e3 authored Nov 02, 2017 by Adam Wallis Committed by Vinod Koul Nov 08, 2017

dmaengine: dmatest: warn user when dma test times out

Commit adfa543e ("dmatest: don't use set_freezable_with_signal()")
introduced a bug (that is in fact documented by the patch commit text)
that leaves behind a dangling pointer. Since the done_wait structure is
allocated on the stack, future invocations to the DMATEST can produce
undesirable results (e.g., corrupted spinlocks). Ideally, this would be
cleaned up in the thread handler, but at the very least, the kernel
is left in a very precarious scenario that can lead to some long debug
sessions when the crash comes later.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=197605

Signed-off-by: Adam Wallis <awallis@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

parent 2bd6bf03

drivers/dma/dmatest.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -702,6 +702,7 @@ static int dmatest_func(void *data)
	* free it this time?" dancing. For now, just		* free it this time?" dancing. For now, just
	* leave it dangling.		* leave it dangling.
	*/		*/
			WARN(1, "dmatest: Kernel stack may be corrupted!!\n");
	dmaengine_unmap_put(um);		dmaengine_unmap_put(um);
	result("test timed out", total_tests, src_off, dst_off,		result("test timed out", total_tests, src_off, dst_off,
	len, 0);		len, 0);