From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760067AbcB1VOi (ORCPT ); Sun, 28 Feb 2016 16:14:38 -0500 Received: from smtp34.i.mail.ru ([94.100.177.94]:40936 "EHLO smtp34.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755117AbcB1VOf (ORCPT ); Sun, 28 Feb 2016 16:14:35 -0500 From: Stas Sergeev To: stsp@list.ru Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH v3 0/2] make sigaltstack() compatible with swapcontext() Date: Mon, 29 Feb 2016 00:13:18 +0300 Message-Id: <1456694000-16395-1-git-send-email-stsp@list.ru> X-Mailer: git-send-email 2.7.2 X-Mras: Ok Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following patches make it possible to use swapcontext() in a sighandler that works on sigaltstack. The approach is inspired by Andy Lutomirski's suggestion that sigaltstack should disarm itself after saving into uc_stack: https://lkml.org/lkml/2016/2/1/594 I add the SS_AUTODISARM flag that does exactly that. On sighandler exit, the sigaltstack is restored from uc_stack. Another possible name could be SS_ONESHOT, but, since it gets always re-enabled, I choose SS_AUTODISARM. [PATCH 1/2] sigaltstack: implement SS_AUTODISARM flag This patch implements SS_AUTODISARM flag [PATCH 2/2] selftests: Add test for sigaltstack(SS_AUTODISARM) This patch adds the selftest code for new functionality CC: linux-kernel@vger.kernel.org CC: linux-api@vger.kernel.org Diffstat: include/linux/sched.h | 1 include/linux/signal.h | 4 include/uapi/linux/signal.h | 3 kernel/fork.c | 4 kernel/signal.c | 23 ++-- tools/testing/selftests/Makefile | 1 tools/testing/selftests/sigaltstack/Makefile | 8 + tools/testing/selftests/sigaltstack/sas.c | 151 +++++++++++++++++++++++++++ 8 files changed, 182 insertions(+), 13 deletions(-)