From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonas Bonn Subject: Re: pt_regs leak into userspace (was Re: [PATCH v3 20/71] ARC: Signal handling) Date: Fri, 15 Feb 2013 08:23:44 +0100 Message-ID: References: <1359024639-21915-1-git-send-email-vgupta@synopsys.com> <1359024639-21915-9-git-send-email-vgupta@synopsys.com> <51189D2F.4030000@synopsys.com> <5118C458.2070205@synopsys.com> <20130211140704.GI4503@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-la0-f41.google.com ([209.85.215.41]:33800 "EHLO mail-la0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935388Ab3BOHZM (ORCPT ); Fri, 15 Feb 2013 02:25:12 -0500 In-Reply-To: <20130211140704.GI4503@ZenIV.linux.org.uk> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Al Viro Cc: Vineet Gupta , Arnd Bergmann , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" On 11 February 2013 15:07, Al Viro wrote: > I'd suggest asking itanic folks; they do *not* put callee-saved stuff into > sigcontext. AFAICS, they don't have setcontext() implemented as a syscall > at all - it's done as sigprocmask() + doing to callee-saved registers what > longjmp() does. Just to round off this discussion, after giving it some more thought I agree that the case where you would need callee-saved registers restored is probably rather pathological. Any sane use of get/set/swapcontext is manageable without this. So, Vineet, I'm now convinced your approach is sound. I will probably amend the OpenRISC arch to behave similarly. Consider your entire patch Acked now. /Jonas