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 80F0B3857809 for ; Thu, 27 May 2021 16:48:23 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 80F0B3857809 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-219-s02iBocPPgy7fWpaOyQSCQ-1; Thu, 27 May 2021 12:48:21 -0400 X-MC-Unique: s02iBocPPgy7fWpaOyQSCQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6FBD2107ACCA; Thu, 27 May 2021 16:48:19 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-113-228.ams2.redhat.com [10.36.113.228]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 77C8270584; Thu, 27 May 2021 16:48:18 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: Adhemerval Zanella via Libc-alpha Subject: Re: [PATCH 08/11] nptl: Move cancel state out of cancelhandling References: <20210526165728.1772546-1-adhemerval.zanella@linaro.org> <20210526165728.1772546-9-adhemerval.zanella@linaro.org> <87y2c1pda2.fsf@oldenburg.str.redhat.com> <9ca99c3f-f65a-cd4e-4ee9-a6746093f871@linaro.org> Date: Thu, 27 May 2021 18:48:16 +0200 In-Reply-To: <9ca99c3f-f65a-cd4e-4ee9-a6746093f871@linaro.org> (Adhemerval Zanella's message of "Thu, 27 May 2021 13:40:21 -0300") Message-ID: <871r9sm8bz.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 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-12.7 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_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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, 27 May 2021 16:48:25 -0000 * Adhemerval Zanella: > On 26/05/2021 15:20, Florian Weimer wrote: >> * Adhemerval Zanella via Libc-alpha: >> >>> diff --git a/nptl/descr.h b/nptl/descr.h >>> index a120365f88..a3084fdf60 100644 >>> --- a/nptl/descr.h >>> +++ b/nptl/descr.h >> >>> @@ -407,6 +401,10 @@ struct pthread >>> /* Used on strsignal. */ >>> struct tls_internal_t tls_state; >>> >>> + /* Thread cancel state (PTHREAD_CANCEL_ENABLE or >>> + PTHREAD_CANCEL_DISABLE). */ >>> + unsigned char cancelstate; >> >> You could move this into the padding after the c11 flag, I think. > > Right, I moved to below c11. What kind of constraint we have for the > 'struct pthread' regarding its internal member layout? We have a couple > of unused fields and might be good to clean them up. The sanitizers depend on the size to derive the TLS memory area from the thread pointer. >> I think there is an implied dependency on PTHREAD_CANCEL_ENABLE == 0 in >> __tls_init_tp and somewhere in pthread_create. Maybe add a static >> assert for PTHREAD_CANCEL_ENABLE == 0? > > I think it would be better to add an initialization on __tls_init_tp, > similar to get_cached_stack. It would be better if we consolidate > the 'struct pthread' initialization in a common place. We depend a lot on zero initialization, though. Maybe it would be better to use memset in get_cached_stack. Unrelated change, of course. Thanks, Florian