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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 63EF6385782D for ; Fri, 16 Feb 2024 21:17:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 63EF6385782D Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 63EF6385782D Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1708118248; cv=none; b=PnCJLfd0V4Piv1/jgTVGGauW4Se5OJBKt1vROETQ2c/wUaa5hDEXdSrKPhboY5DP7jjV/4IgvSJ9iGphCFQmZC1PL186sKNXUy2BqeiR+cDUPVNbGqCnC2weBGKUwPnzLGJJfkbzolmSLgwfRf6+TOr3ahgFo/ZYG4zQnpK+0NE= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1708118248; c=relaxed/simple; bh=ZlzonBU5rceX90n8HPlmyYufQq6Kb66ixBO7rVfo2W8=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=Rq2KMfc0ZN/DjpQOPMW3xRY0d+H3qEJUN3sD6zp/JVdVxKu8S94PPkDroyW67h2ce9ZZSr3qprfrtIuplNPeuuVJs8zxNyrv10M+tPXB8lSzkUAS0aNiKBlE9U89ODpuiCk87gyL9H1Z/OPbDTbIshdBhibrYVzGQSJl+E5EhGc= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708118247; 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; bh=XWrlIa7Px4l+BeTPYkOpH30rxPsX//RqPUfydkt1VH8=; b=T4tBshGwhKrdxnd7PnPIwc1G/VUyTSfdNlBcfI8ZlNl99fJzyu3DYqLkOq9PULW7LRn1Pt ldJ6V6604Y9w+/S75HgMIl5ZJFPxUlpkbTxe07Ot5KdAzAq3416G+zd4WBV6Q4jhHlwff3 znl72Bc8Duf1fWemFjuekXoEjvSCDNU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-258-5J1Hv5W6PvG-uVys7Du68A-1; Fri, 16 Feb 2024 16:17:23 -0500 X-MC-Unique: 5J1Hv5W6PvG-uVys7Du68A-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 40A9283B86C; Fri, 16 Feb 2024 21:17:23 +0000 (UTC) Received: from greed.delorie.com (unknown [10.22.8.101]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2C4351C066AA; Fri, 16 Feb 2024 21:17:23 +0000 (UTC) Received: from greed.delorie.com.redhat.com (localhost [127.0.0.1]) by greed.delorie.com (8.15.2/8.15.2) with ESMTP id 41GLHMDp315339; Fri, 16 Feb 2024 16:17:22 -0500 From: DJ Delorie To: Michael Jeanson Cc: libc-alpha@sourceware.org, mathieu.desnoyers@efficios.com Subject: Re: [PATCH v8 2/8] Add rseq extensible ABI support In-Reply-To: Date: Fri, 16 Feb 2024 16:17:22 -0500 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Michael Jeanson writes: > When rseq registration is disabled by tunable we still need to allocate > an rseq block because application code is allowed to check for the > registration status by reading 'rseq->cpu_id'. So in this case we > allocate the minimum ABI size of 32. Ok, I admit that was confusing ;-) > Internally this is recorded in 'dl_tls_rseq_size' but the application > visible '_rseq_size' is left at 0 (this happens in > sysdeps/nptl/dl-tls_init_tp.c). A comment in sysdeps/nptl/dl-tls_init_tp.c after the if{} noting what the variables would be otherwise might be useful. At least that was one of the places I looked at when trying to figure this out. > I'll try making this more clear with additional comments and finding a > name for 'rseq_size' that is not so close to '__rseq_size'. Perhaps "rseq_alloc_size" ?