From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757310AbaGWACn (ORCPT ); Tue, 22 Jul 2014 20:02:43 -0400 Received: from mail-pd0-f178.google.com ([209.85.192.178]:42132 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757283AbaGWACl (ORCPT ); Tue, 22 Jul 2014 20:02:41 -0400 Date: Tue, 22 Jul 2014 17:01:03 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Andrew Morton cc: Sasha Levin , Vlastimil Babka , Konstantin Khlebnikov , Johannes Weiner , Michel Lespinasse , Lukas Czerner , Dave Jones , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] shmem: fix faulting into a hole, not taking i_mutex: fix Message-ID: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sasha reports various nasty trinity crashes when shmem_fault() tries to finish_wait(), we guess from rare cases when the wait_queue_head on shmem_fallocate()'s stack has already gone. Fix those by using TASK_UNINTERRUPIBLE instead of TASK_KILLABLE in prepare_to_wait(), that's much simpler and safer: TASK_KILLABLE was a nice aspiration, but not worth any more hassle. Reported-and-tested-by: Sasha Levin Signed-off-by: Hugh Dickins --- Andrew, please fold this into shmem-fix-faulting-into-a-hole-not-taking-i_mutex.patch before sending the fixes on to Linus - thanks. mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- mmotm/mm/shmem.c 2014-07-22 16:35:49.683985586 -0700 +++ linux/mm/shmem.c 2014-07-22 16:36:35.459984108 -0700 @@ -1283,7 +1283,7 @@ static int shmem_fault(struct vm_area_st shmem_falloc_waitq = shmem_falloc->waitq; prepare_to_wait(shmem_falloc_waitq, &shmem_fault_wait, - TASK_KILLABLE); + TASK_UNINTERRUPTIBLE); spin_unlock(&inode->i_lock); schedule();