From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932493AbaE3GwE (ORCPT ); Fri, 30 May 2014 02:52:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2415 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932093AbaE3GwC (ORCPT ); Fri, 30 May 2014 02:52:02 -0400 From: Naoya Horiguchi To: Andrew Morton Cc: Tony Luck , Andi Kleen , Kamil Iskra , Borislav Petkov , Chen Gong , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 1/3] memory-failure: Send right signal code to correct thread Date: Fri, 30 May 2014 02:51:08 -0400 Message-Id: <1401432670-24664-2-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: <1401432670-24664-1-git-send-email-n-horiguchi@ah.jp.nec.com> References: <53877e9c.8b2cdc0a.1604.ffffea43SMTPIN_ADDED_BROKEN@mx.google.com> <1401432670-24664-1-git-send-email-n-horiguchi@ah.jp.nec.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tony Luck When a thread in a multi-threaded application hits a machine check because of an uncorrectable error in memory - we want to send the SIGBUS with si.si_code = BUS_MCEERR_AR to that thread. Currently we fail to do that if the active thread is not the primary thread in the process. collect_procs() just finds primary threads and this test: if ((flags & MF_ACTION_REQUIRED) && t == current) { will see that the thread we found isn't the current thread and so send a si.si_code = BUS_MCEERR_AO to the primary (and nothing to the active thread at this time). We can fix this by checking whether "current" shares the same mm with the process that collect_procs() said owned the page. If so, we send the SIGBUS to current (with code BUS_MCEERR_AR). Reported-by: Otto Bruggeman Signed-off-by: Tony Luck Cc: Andi Kleen Cc: Borislav Petkov Cc: Chen Gong Acked-by: Naoya Horiguchi --- mm/memory-failure.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git mmotm-2014-05-21-16-57.orig/mm/memory-failure.c mmotm-2014-05-21-16-57/mm/memory-failure.c index e3154d99b87f..b73098ee91e6 100644 --- mmotm-2014-05-21-16-57.orig/mm/memory-failure.c +++ mmotm-2014-05-21-16-57/mm/memory-failure.c @@ -204,9 +204,9 @@ static int kill_proc(struct task_struct *t, unsigned long addr, int trapno, #endif si.si_addr_lsb = page_size_order(page) + PAGE_SHIFT; - if ((flags & MF_ACTION_REQUIRED) && t == current) { + if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) { si.si_code = BUS_MCEERR_AR; - ret = force_sig_info(SIGBUS, &si, t); + ret = force_sig_info(SIGBUS, &si, current); } else { /* * Don't use force here, it's convenient if the signal -- 1.9.3