From mboxrd@z Thu Jan 1 00:00:00 1970 From: Max Filippov Subject: [PATCHv2 2/2] xtensa: don't use alternate signal stack on threads Date: Sat, 26 Oct 2013 05:03:05 +0400 Message-ID: <1382749385-29062-3-git-send-email-jcmvbkbc@gmail.com> References: <1382749385-29062-1-git-send-email-jcmvbkbc@gmail.com> Return-path: Received: from mail-wi0-f181.google.com ([209.85.212.181]:43680 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752117Ab3JZBD1 (ORCPT ); Fri, 25 Oct 2013 21:03:27 -0400 In-Reply-To: <1382749385-29062-1-git-send-email-jcmvbkbc@gmail.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Chris Zankel Cc: Marc Gauthier , linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org, Baruch Siach , stable@vger.kernel.org, Max Filippov From: Baruch Siach 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. Cc: Signed-off-by: Baruch Siach Signed-off-by: Max Filippov --- arch/xtensa/kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 718eca1..98b67d5 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -341,7 +341,7 @@ static int setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 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; } -- 1.8.1.4