From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 125553 invoked by alias); 2 Jun 2017 19:02:05 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 125543 invoked by uid 89); 2 Jun 2017 19:02:05 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=our X-HELO: mx1.redhat.com DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E967F142A62 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=fweimer@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com E967F142A62 Subject: Re: [PATCH v3 2/2] posix: Implement preadv2 and pwritev2 To: Adhemerval Zanella , Zack Weinberg Cc: "H.J. Lu" , Siddhesh Poyarekar , GNU C Library References: <1493901791-13438-1-git-send-email-adhemerval.zanella@linaro.org> <1493901791-13438-2-git-send-email-adhemerval.zanella@linaro.org> <8ceeaabf-110f-31fe-516b-18f2fe6710f8@gotplt.org> <7412360d-c776-532b-e22c-dd3f0048cfba@linaro.org> <7f07b067-a074-d670-88b1-3da917451c71@redhat.com> From: Florian Weimer Message-ID: Date: Fri, 02 Jun 2017 19:02:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2017-06/txt/msg00114.txt.bz2 On 06/02/2017 08:19 PM, Adhemerval Zanella wrote: > I am even more confident this is indeed a miscompilation from GCC7 branch. > Using a previous built x86_64-linux-gnu with GCC6 branch I saw no issue, however > using GCC7 there is indeed the test failure. And it seems to show only for kernels > with support for p{read,write}v2 syscall, which means it stress the default > SYSCALL_CANCEL path. > > However, running a GCC6 built testcase with a GCC7 build glibc (with testrun.sh) > I saw no issue. The GCC7 built test also fails with a GCC6 built glibc. I will > check with GCC master to see if this is something only on GCC7 branch or if it > is still on master. > > Also, I seems that for GCC7 only x86_64-linux-gnu is affect on x86. I see it with GCC 6.3 on Fedora 24, x86-64 as well. It could be a broken GCC 7 patch that was backported, or perhaps our constraints for the syscall instruction are off. Florian