From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS17314 8.43.84.0/22 X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 98BBD1F8C6 for ; Thu, 26 Aug 2021 11:35:04 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 82C243858007 for ; Thu, 26 Aug 2021 11:35:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 82C243858007 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1629977703; bh=ij/kdPRIGprHxPLZ9Vc7npUJdRvdrhVFRXlS70DuL14=; h=To:Subject:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=OFxcEBWBpSiOibTNyO3GuyefEa9lKUSWJt/3+vhhvSwlXbOO9kOG7xFdEqDteLZkA MGoqnlw1NqiiqHOHXQvHTZLKkTXsYfp9IglUJS1yfrR84h61e2LXL7+4iTmw9+LX71 NGeLObldnGo+E8ZuFrqWl00Q5slRALpmXMtj4W5s= 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 1AEA3385843B for ; Thu, 26 Aug 2021 11:34:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1AEA3385843B 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-585-l8-H9R8cNa-crN1C3aXkAw-1; Thu, 26 Aug 2021 07:34:31 -0400 X-MC-Unique: l8-H9R8cNa-crN1C3aXkAw-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 8BB21193F575; Thu, 26 Aug 2021 11:34:30 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.194.140]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B3E41669F3; Thu, 26 Aug 2021 11:34:29 +0000 (UTC) To: Adhemerval Zanella Subject: Re: [PATCH v2 05/19] nptl: Move setxid flag out of cancelhandling References: <20210823195047.543237-1-adhemerval.zanella@linaro.org> <20210823195047.543237-6-adhemerval.zanella@linaro.org> Date: Thu, 26 Aug 2021 13:34:27 +0200 In-Reply-To: <20210823195047.543237-6-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Mon, 23 Aug 2021 16:50:33 -0300") Message-ID: <87tujc783g.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-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: , From: Florian Weimer via Libc-alpha Reply-To: Florian Weimer Cc: libc-alpha@sourceware.org Errors-To: libc-alpha-bounces+e=80x24.org@sourceware.org Sender: "Libc-alpha" * Adhemerval Zanella: > Now that the thread state is tracked by 'joinstate' field, there is no > need to keep the setxid flag within the 'cancelhandling'. It simplifies > the atomic code to set and reset it (since there is no need to handle > the thread state concurrent update). Some of this functionality reimplements the tidlock. There is some functionality around thread creation, but I do not know if the synchronization is entirely correct. This makes it rather difficult to review changes. It's also not clear to me if we need to do anything to prevent early setxid calls: > /* Don't allow setxid until cloned. */ I suspect this should just look at the TID instead. We create the thread with all signals blocked, so once there is a TID (and the thread has not exited), it is safe to send the signal. > diff --git a/nptl/descr.h b/nptl/descr.h > index 4b2db6edab..563b152bff 100644 > --- a/nptl/descr.h > +++ b/nptl/descr.h > + /* Indicate whether thread is supposed to change XID. */ > + int setxid_flag; This should document the possible values. Thanks, Florian