From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757285Ab3KYOPx (ORCPT ); Mon, 25 Nov 2013 09:15:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:58902 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754047Ab3KYNxm (ORCPT ); Mon, 25 Nov 2013 08:53:42 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Chris Zankel" , "Baruch Siach" , "Max Filippov" Date: Mon, 25 Nov 2013 13:44:29 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 68/87] xtensa: don't use alternate signal stack on threads In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.212 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.53-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Baruch Siach commit cba9a90053e3b7973eff4f1946f33032e98eeed5 upstream. According to create_thread(3): "The new thread does not inherit the creating thread's alternate signal stack". Since commit f9a3879a (Fix sigaltstack corruption among cloned threads), current->sas_ss_size is set to 0 for cloned processes sharing VM with their parent. Don't use the (nonexistent) alternate signal stack in this case. This has been broken since commit 29c4dfd9 ([XTENSA] Remove non-rt signal handling). Fixes the SA_ONSTACK part of the nptl/tst-cancel20 test from uClibc. Signed-off-by: Baruch Siach Signed-off-by: Max Filippov Signed-off-by: Chris Zankel Signed-off-by: Ben Hutchings --- arch/xtensa/kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -346,7 +346,7 @@ static void setup_frame(int sig, struct sp = regs->areg[1]; - if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) { + if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && sas_ss_flags(sp) == 0) { sp = current->sas_ss_sp + current->sas_ss_size; }