Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753536AbYFAP3Y (ORCPT ); Sun, 1 Jun 2008 11:29:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752138AbYFAP3N (ORCPT ); Sun, 1 Jun 2008 11:29:13 -0400 Received: from x346.tv-sign.ru ([89.108.83.215]:58890 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752032AbYFAP3M (ORCPT ); Sun, 1 Jun 2008 11:29:12 -0400 Date: Sun, 1 Jun 2008 19:30:45 +0400 From: Oleg Nesterov To: Andrew Morton Cc: "Eric W. Biederman" , Ingo Molnar , Linus Torvalds , Roland McGrath , linux-kernel@vger.kernel.org Subject: [PATCH 3/3] coredump: zap_threads() must skip kernel threads Message-ID: <20080601153045.GA8244@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 30 The main loop in zap_threads() must skip kthreads which may use the same mm. Otherwise we "kill" this thread erroneously (for example, it can not fork or exec after that), and the coredumping task stucks in the TASK_UNINTERRUPTIBLE state forever because of the wrong ->core_waiters count. Signed-off-by: Oleg Nesterov --- 26-rc2/fs/exec.c~3_CD_FIX_RACE_USE_MM 2008-05-31 20:05:21.000000000 +0400 +++ 26-rc2/fs/exec.c 2008-06-01 19:04:39.000000000 +0400 @@ -1568,11 +1568,13 @@ static inline int zap_threads(struct tas for_each_process(g) { if (g == tsk->group_leader) continue; + if (g->flags & PF_KTHREAD) + continue; p = g; do { if (p->mm) { - if (p->mm == mm) { + if (unlikely(p->mm == mm)) { lock_task_sighand(p, &flags); zap_process(p); unlock_task_sighand(p, &flags); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/