From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id CEE656B01F2 for ; Thu, 19 Aug 2010 06:54:10 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o7JAs8VN007402 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 19 Aug 2010 19:54:08 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 21C5C45DE60 for ; Thu, 19 Aug 2010 19:54:08 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 01BEE45DE4D for ; Thu, 19 Aug 2010 19:54:08 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 9B5D91DB8037 for ; Thu, 19 Aug 2010 19:54:07 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 43987E38001 for ; Thu, 19 Aug 2010 19:54:07 +0900 (JST) From: KOSAKI Motohiro Subject: [PATCH 2/2] oom: fix tasklist_lock leak In-Reply-To: <20100819194707.5FC4.A69D9226@jp.fujitsu.com> References: <20100819194707.5FC4.A69D9226@jp.fujitsu.com> Message-Id: <20100819195346.5FCA.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 19 Aug 2010 19:54:06 +0900 (JST) Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , David Rientjes , Linus Torvalds , KAMEZAWA Hiroyuki List-ID: commit 0aad4b3124 (oom: fold __out_of_memory into out_of_memory) introduced tasklist_lock leak. Then it caused following obvious danger warings and panic. ================================================ [ BUG: lock held when returning to user space! ] ------------------------------------------------ rsyslogd/1422 is leaving the kernel with locks still held! 1 lock held by rsyslogd/1422: #0: (tasklist_lock){.+.+.+}, at: [] out_of_memory+0x164/0x3f0 BUG: scheduling while atomic: rsyslogd/1422/0x00000002 INFO: lockdep is turned off. This patch fixes it. Signed-off-by: KOSAKI Motohiro --- mm/oom_kill.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 17d48a6..c48c5ef 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -646,6 +646,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, unsigned long freed = 0; unsigned int points; enum oom_constraint constraint = CONSTRAINT_NONE; + int killed = 0; blocking_notifier_call_chain(&oom_notify_list, 0, &freed); if (freed > 0) @@ -683,7 +684,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, if (!oom_kill_process(current, gfp_mask, order, 0, totalpages, NULL, nodemask, "Out of memory (oom_kill_allocating_task)")) - return; + goto out; } retry: @@ -691,7 +692,7 @@ retry: constraint == CONSTRAINT_MEMORY_POLICY ? nodemask : NULL); if (PTR_ERR(p) == -1UL) - return; + goto out; /* Found nothing?!?! Either we hang forever, or we panic. */ if (!p) { @@ -703,13 +704,15 @@ retry: if (oom_kill_process(p, gfp_mask, order, points, totalpages, NULL, nodemask, "Out of memory")) goto retry; + killed = 1; +out: read_unlock(&tasklist_lock); /* * Give "p" a good chance of killing itself before we * retry to allocate memory unless "p" is current */ - if (!test_thread_flag(TIF_MEMDIE)) + if (killed && !test_thread_flag(TIF_MEMDIE)) schedule_timeout_uninterruptible(1); } -- 1.6.5.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org