From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 71084 invoked by alias); 13 Jul 2018 19:05:17 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 71068 invoked by uid 89); 13 Jul 2018 19:05:16 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 spammy=rights, reserved X-HELO: mail-qk0-f196.google.com Return-Path: Subject: Re: V2: [PATCH 01/24] x86: Rename __glibc_reserved1 to feature_1 in tcbhead_t [BZ #22563] To: Jeff Law , "H.J. Lu" , libc-alpha@sourceware.org References: <20180613153207.57232-1-hjl.tools@gmail.com> <20180613153207.57232-2-hjl.tools@gmail.com> <20180713131908.GB2606@gmail.com> <663c719e-febe-4884-f814-bf79e2e553ec@redhat.com> From: Carlos O'Donell Message-ID: <556db9d0-d50d-ddaf-3274-ae82f63806d3@redhat.com> Date: Fri, 13 Jul 2018 19:05:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2018-07/txt/msg00395.txt.bz2 On 07/13/2018 02:55 PM, Jeff Law wrote: > On 07/13/2018 12:51 PM, Carlos O'Donell wrote: >> On 07/13/2018 09:19 AM, H.J. Lu wrote: >>> On Wed, Jun 13, 2018 at 08:31:44AM -0700, H.J. Lu wrote: >>>> This will be used by CET run-time control. >>>> >>>> [BZ #22563] >>>> * nptl/pthread_create.c (__pthread_create_2_1): Use >>>> THREAD_COPY_ADDITONAL_INFO to copy additonal info if defined. >>>> * sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New. >>>> * sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): >>>> Likewise. >>>> * sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1 >>>> to feature_1. >>>> * sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise. >>>> * sysdeps/unix/sysv/linux/x86/pthreaddef.h: New file. >>> >>> Here is the updated patch to add feature_1 to tcbhead_t and >>> introduce macros for CET enabling. OK for master? >> >> Fix the typo-prone macro API and post a v3 please. >> >> Thank you. > Umm, has this been tested with the sanitizers? I thought they used that > field. The size of tcbhead_t has not changed, which is something that might impact the santiziers. But now that you mention it, why do I vaguely remember a conversation about the santizers using the reserved bytes as storage for themselves? Is that what you are talking about? HJ, could you look into this please? I think the sanitizers are not within their rights to use any bytes in the tcbhead_t structure, particularly reserved bytes. We should coordinate with them, but that should not stop the acceptance of this patch in 2.28. Cheers, Carlos.