From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id 801AD3858406 for ; Thu, 26 Aug 2021 14:24:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 801AD3858406 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-365-nxRwTsquNsa2ekr931ZBiw-1; Thu, 26 Aug 2021 10:24:37 -0400 X-MC-Unique: nxRwTsquNsa2ekr931ZBiw-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id CE4C05F9CF; Thu, 26 Aug 2021 14:24:36 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.194.140]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 018061ACC7; Thu, 26 Aug 2021 14:24:35 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: libc-alpha@sourceware.org Subject: Re: [PATCH v2 10/19] nptl: Use tidlock when accessing TID on pthread_getaffinity_np References: <20210823195047.543237-1-adhemerval.zanella@linaro.org> <20210823195047.543237-11-adhemerval.zanella@linaro.org> Date: Thu, 26 Aug 2021 16:24:34 +0200 In-Reply-To: <20210823195047.543237-11-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Mon, 23 Aug 2021 16:50:38 -0300") Message-ID: <874kbc707x.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-12.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Aug 2021 14:24:41 -0000 * Adhemerval Zanella: > Checked on x86_64-linux-gnu. > --- > nptl/pthread_getaffinity.c | 22 +++++++++++++++++----- > 1 file changed, 17 insertions(+), 5 deletions(-) > > diff --git a/nptl/pthread_getaffinity.c b/nptl/pthread_getaffinity.c > index 18261ddae0..5268d86e6e 100644 > --- a/nptl/pthread_getaffinity.c > +++ b/nptl/pthread_getaffinity.c > @@ -29,12 +29,24 @@ > int > __pthread_getaffinity_np (pthread_t th, size_t cpusetsize, cpu_set_t *cpuset) > { > - const struct pthread *pd = (const struct pthread *) th; > + struct pthread *pd = (struct pthread *) th; > > - int res = INTERNAL_SYSCALL_CALL (sched_getaffinity, pd->tid, > - MIN (INT_MAX, cpusetsize), cpuset); > - if (INTERNAL_SYSCALL_ERROR_P (res)) > - return INTERNAL_SYSCALL_ERRNO (res); > + /* Block all signal, since the lock is recursive and used on pthread_cancel > + (which should be async-signal-safe). */ The pthread_cancel reference looks like a cut-and-paste-bug. > + sigset_t oldmask; > + __libc_signal_block_all (&oldmask); > + lll_lock (pd->tidlock, LLL_PRIVATE); > + > + int res = pd->tid == 0 > + ? -ESRCH > + : INTERNAL_SYSCALL_CALL (sched_getaffinity, pd->tid, > + MIN (INT_MAX, cpusetsize), cpuset); > + > + lll_unlock (pd->tidlock, LLL_PRIVATE); > + __libc_signal_restore_set (&oldmask); > + > + if (res < 0) > + return -res; ESRCH doesn't look like the right error code here. Should we return an affinity mask without any bits set? Thanks, Florian