From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752805Ab2KSD11 (ORCPT ); Sun, 18 Nov 2012 22:27:27 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:54341 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751859Ab2KSD10 (ORCPT ); Sun, 18 Nov 2012 22:27:26 -0500 Date: Sun, 18 Nov 2012 22:27:24 -0500 (EST) Message-Id: <20121118.222724.1495808364736017374.davem@davemloft.net> To: viro@ZenIV.linux.org.uk Cc: torvalds@linux-foundation.org, monstr@monstr.eu, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: sigaltstack fun From: David Miller In-Reply-To: <20121119023507.GK16916@ZenIV.linux.org.uk> References: <20121119011013.GJ16916@ZenIV.linux.org.uk> <20121118.203005.151867624663051294.davem@davemloft.net> <20121119023507.GK16916@ZenIV.linux.org.uk> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro Date: Mon, 19 Nov 2012 02:35:07 +0000 > sparc64: not any error from do_sigaltstack() should fail rt_sigreturn() > > If a signal handler is executed on altstack and another signal comes, > we will end up with rt_sigreturn() on return from the second handler > getting -EPERM from do_sigaltstack(). It's perfectly OK, since we > are not asking to change the settings; in fact, they couldn't have been > changed during the second handler execution exactly because we'd been > on altstack all along. 64bit sigreturn on sparc treats any error from > do_sigaltstack() as "SIGSEGV now"; we need to switch to the same semantics > we are using on other architectures. > > Cc: stable@vger.kernel.org > Signed-off-by: Al Viro Applied, thanks.