From: Adam Wallis Date: Thu, 2 Nov 2017 12:53:30 +0000 (-0400) Subject: dmaengine: dmatest: warn user when dma test times out X-Git-Tag: v4.19~2206^2~13^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a9df21e34b422f79d9a9fa5c3eff8c2a53491be6;p=platform%2Fkernel%2Flinux-rpi.git dmaengine: dmatest: warn user when dma test times out Commit adfa543e7314 ("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 Signed-off-by: Vinod Koul --- diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 34ff532..47edc7f 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -702,6 +702,7 @@ static int dmatest_func(void *data) * free it this time?" dancing. For now, just * leave it dangling. */ + WARN(1, "dmatest: Kernel stack may be corrupted!!\n"); dmaengine_unmap_put(um); result("test timed out", total_tests, src_off, dst_off, len, 0);