From 7e4b7db9d1c3b5176a436e2407b2147b3f9c8071 Mon Sep 17 00:00:00 2001 From: Adam Wallis Date: Thu, 2 Nov 2017 08:53:30 -0400 Subject: [PATCH] dmaengine: dmatest: warn user when dma test times out Commit ea99d7979275 ("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 --- drivers/dma/dmatest.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 34ff53290b037..47edc7fbf91f5 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); -- 2.39.5