From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA76BC433F5 for ; Wed, 2 Feb 2022 15:01:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345314AbiBBPB0 (ORCPT ); Wed, 2 Feb 2022 10:01:26 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:26200 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345293AbiBBPBW (ORCPT ); Wed, 2 Feb 2022 10:01:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643814081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5LdYe0/2yXLTD/OVAh9OHIYB9qOHTi1p5PIuVGDR2rI=; b=h7Jgz2QeRs8PY0XLBuohBp1W/iLVtgXdX1cNOjLx8z67sLT5y0eHXkiCoolCN+9Twu9Yx0 YaTAefYaw5EwqOdMqYQFVa2BXdDbTERhqozAKS7U3coWL1THUsK6YYByFaptWKDZbSXMQJ LGZwZIqSnQ6lVsz/52vFGr/ABp+Iviw= 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-508-Ewx3BCiyOa6z_39Tp6R5sQ-1; Wed, 02 Feb 2022 10:01:20 -0500 X-MC-Unique: Ewx3BCiyOa6z_39Tp6R5sQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D03ED84BA44; Wed, 2 Feb 2022 15:01:18 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.205]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F24A36E1ED; Wed, 2 Feb 2022 15:01:16 +0000 (UTC) From: Florian Weimer To: Mathieu Desnoyers Cc: Chris Kennelly , Paul Turner , Peter Oskolkov , libc-alpha , linux-kernel , Peter Zijlstra Subject: Re: Aligning tcmalloc with glibc 2.35 rseq ABI References: <432231420.24682.1643727496135.JavaMail.zimbra@efficios.com> <87mtja1fuz.fsf@oldenburg.str.redhat.com> <875ypx1x0d.fsf@oldenburg.str.redhat.com> <1375227765.27051.1643801804042.JavaMail.zimbra@efficios.com> <770517862.27112.1643807335312.JavaMail.zimbra@efficios.com> Date: Wed, 02 Feb 2022 16:01:15 +0100 In-Reply-To: <770517862.27112.1643807335312.JavaMail.zimbra@efficios.com> (Mathieu Desnoyers's message of "Wed, 2 Feb 2022 08:08:55 -0500 (EST)") Message-ID: <87o83pxqh0.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mathieu Desnoyers: > More to the point: is ptrdiff_t the correct type here ? I think so. > Do we want to revert the ABI and wait another 6 months before we > bring back rseq into glibc just for this ? I'm not sure this limitation > justifies it. > > So if there is a quick way to fix that before the official 2.35 release, > I'm all for it, otherwise I cannot say that __rseq_offset being an "int" > rather than a "ptrdiff_t" will make much real-life difference (unless > I'm proven wrong). But we will be stuck with this quirk forever. I'm going to post a patch. It's fairly small. Thanks, Florian