From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4950C282DE for ; Wed, 5 Jun 2019 08:56:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 935CB20866 for ; Wed, 5 Jun 2019 08:56:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726762AbfFEI4U (ORCPT ); Wed, 5 Jun 2019 04:56:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60380 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726708AbfFEI4U (ORCPT ); Wed, 5 Jun 2019 04:56:20 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1C53788307; Wed, 5 Jun 2019 08:56:14 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.159]) by smtp.corp.redhat.com (Postfix) with SMTP id 76A465D705; Wed, 5 Jun 2019 08:56:06 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 5 Jun 2019 10:56:12 +0200 (CEST) Date: Wed, 5 Jun 2019 10:56:04 +0200 From: Oleg Nesterov To: Linus Torvalds Cc: Andrew Morton , Deepa Dinamani , Linux List Kernel Mailing , Arnd Bergmann , Davidlohr Bueso , Jens Axboe , Davidlohr Bueso , e@80x24.org, Jason Baron , linux-fsdevel , linux-aio@kvack.org, omar.kilani@gmail.com, Thomas Gleixner , stable , Al Viro , "Eric W. Biederman" , David Laight Subject: Re: [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask() Message-ID: <20190605085604.GA32406@redhat.com> References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <20190604134117.GA29963@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 05 Jun 2019 08:56:19 +0000 (UTC) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 06/04, Linus Torvalds wrote: > > On Tue, Jun 4, 2019 at 6:41 AM Oleg Nesterov wrote: > > > > This is the minimal fix for stable, I'll send cleanups later. > > Ugh. I htink this is correct, but I wish we had a better and more > intuitive interface. Yes, > In particular, since restore_user_sigmask() basically wants to check > for "signal_pending()" anyway No, the caller should check signal_pending() anyway and this is enough. > > - restore_user_sigmask(ksig.sigmask, &sigsaved); > > - if (signal_pending(current) && !ret) > > + > > + interrupted = signal_pending(current); > > + restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted); > > + if (interrupted && !ret) > > ret = -ERESTARTNOHAND; > > are wrong to begin with, This is fs/aio.c and I have already mentioned that this code doesn't look right anyway. > IOW, I think the above could become > > ret = restore_user_sigmask(ksig.sigmask, &sigsaved, ret, -ERESTARTHAND); > > instead if we just made the right interface decision. I think this particular code should simply do ret = do_io_getevents(...); if (ret == -ERESTARTSYS) ret = -EINTR; restore_user_sigmask(ret == -EINTR); However I agree that another helper(s) which takes/returns the error code makes sense and I was going to do this. Lets do this step by step, I think we should kill sigmask/sigsaved first. Oleg.