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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id C08D13858D3C for ; Wed, 8 Dec 2021 18:09:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C08D13858D3C Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-293-89b1xVYzPGaO8vfQJWRUkA-1; Wed, 08 Dec 2021 13:09:00 -0500 X-MC-Unique: 89b1xVYzPGaO8vfQJWRUkA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2B81E1926DA2; Wed, 8 Dec 2021 18:08:59 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.123]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5231A1971B; Wed, 8 Dec 2021 18:08:58 +0000 (UTC) From: Florian Weimer To: Siddhesh Poyarekar Cc: libc-alpha@sourceware.org Subject: Re: [PATCH 4/8] nptl: Add rseq registration References: <921551c8-0cd3-5fcc-30a4-e0709485e0f1@gotplt.org> Date: Wed, 08 Dec 2021 19:08:56 +0100 In-Reply-To: <921551c8-0cd3-5fcc-30a4-e0709485e0f1@gotplt.org> (Siddhesh Poyarekar's message of "Wed, 8 Dec 2021 23:33:44 +0530") Message-ID: <87ilvzj7ev.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 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.5 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, 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: Wed, 08 Dec 2021 18:09:02 -0000 * Siddhesh Poyarekar: >> +#ifdef RSEQ_SIG >> +static inline void >> +rseq_register_current_thread (struct pthread *self) >> +{ >> + int ret = INTERNAL_SYSCALL_CALL (rseq, >> + &self->rseq_area, sizeof (self->rseq_area), >> + 0, RSEQ_SIG); >> + if (INTERNAL_SYSCALL_ERROR_P (ret)) >> + THREAD_SETMEM (self, rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED); > > Why can't we just leave it as the kernel did when it failed the > syscall? The kernel definitely won't write anything if the failure is ENOSYS. I don't expect the kernel to write something for the other failures, either. Thanks, Florian