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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 EC31CC28CC0 for ; Thu, 30 May 2019 17:21:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB2C325E4A for ; Thu, 30 May 2019 17:21:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbfE3RVw (ORCPT ); Thu, 30 May 2019 13:21:52 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:53606 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725961AbfE3RVw (ORCPT ); Thu, 30 May 2019 13:21:52 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1hWOkN-0000K1-Ck; Thu, 30 May 2019 11:21:47 -0600 Received: from ip72-206-97-68.om.om.cox.net ([72.206.97.68] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1hWOkM-0005Yj-Id; Thu, 30 May 2019 11:21:47 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Oleg Nesterov Cc: Deepa Dinamani , Al Viro , Linus Torvalds , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, arnd@arndb.de, dbueso@suse.de, axboe@kernel.dk, dave@stgolabs.net, e@80x24.org, jbaron@akamai.com, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, omar.kilani@gmail.com, tglx@linutronix.de, stable@vger.kernel.org References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <87woi8rt96.fsf@xmission.com> <871s0grlzo.fsf@xmission.com> <20190530160823.GI22536@redhat.com> Date: Thu, 30 May 2019 12:20:52 -0500 In-Reply-To: <20190530160823.GI22536@redhat.com> (Oleg Nesterov's message of "Thu, 30 May 2019 18:08:24 +0200") Message-ID: <87lfynrh8r.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1hWOkM-0005Yj-Id;;;mid=<87lfynrh8r.fsf@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=72.206.97.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1895Z1ierl2kaF3bw8R919nMbS+HF5Tt3c= X-SA-Exim-Connect-IP: 72.206.97.68 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: pselect/etc semantics X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Oleg Nesterov writes: > On 05/30, Eric W. Biederman wrote: >> >> ebiederm@xmission.com (Eric W. Biederman) writes: >> >> > Which means I believe we have a semantically valid change in behavior >> > that is causing a regression. >> >> I haven't made a survey of all of the functions yet but >> fucntions return -ENORESTARTNOHAND will never return -EINTR and are >> immune from this problem. > > Hmm. handle_signal: > > case -ERESTARTNOHAND: > regs->ax = -EINTR; > break; > > but I am not sure I understand which problem do you mean.. Yes. My mistake. I looked at the transparent restart case for when a signal is not pending and failed to look at what happens when a signal is delivered. So yes. Everything changed does appear to have a behavioral difference where they can now succeed and not return -EINTR. Eric