From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Baruch Siach , Max Filippov , Chris Zankel , Kamal Mostafa Subject: [PATCH 3.8 68/91] xtensa: don't use alternate signal stack on threads Date: Thu, 7 Nov 2013 18:15:23 -0800 Message-Id: <1383876946-2396-69-git-send-email-kamal@canonical.com> In-Reply-To: <1383876946-2396-1-git-send-email-kamal@canonical.com> References: <1383876946-2396-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8.13.13 -stable 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: Kamal Mostafa --- 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 de34d6b..3f4b160 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; } -- 1.8.1.2