From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 86928 invoked by alias); 4 Mar 2020 09:36:14 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 70378 invoked by uid 89); 4 Mar 2020 09:34:22 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-6.5 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=H*i:OQUN, H*i:sk:fZgRj3m, H*i:hVBKidLXDc7A4o X-HELO: us-smtp-1.mimecast.com Received: from us-smtp-delivery-1.mimecast.com (HELO us-smtp-1.mimecast.com) (205.139.110.120) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 04 Mar 2020 09:34:21 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583314459; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lo4zGQ6rY3Q8nYJNdNfNLIPr6vZK94/lxMEDM36omVI=; b=SpIVolcm07q4SF2ridlHnAgc+55REIeWFK6Oy02XJPkR7myEDL05j3AxXfpNGu4QcK19w3 HpzvNhhHrSC2uuNi3BVw0xkzMpmkfQoWKwvqeqyQeD7f/OADclteP4YEH5isawoDditx5/ jYeaOxkQBI+QS/MQzYzqcI/AGbvqHRI= 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-186-yEWgavqdNOWLtLpzqVPBYw-1; Wed, 04 Mar 2020 04:34:17 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 02890107ACCD; Wed, 4 Mar 2020 09:34:17 +0000 (UTC) Received: from oldenburg2.str.redhat.com (ovpn-117-44.ams2.redhat.com [10.36.117.44]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 23F2E5DA7E; Wed, 4 Mar 2020 09:34:15 +0000 (UTC) From: Florian Weimer To: Maxim Blinov Cc: gdb@sourceware.org Subject: Re: use of %fs segment register in x86_64 with -fstack-check References: Date: Wed, 04 Mar 2020 09:36:00 -0000 In-Reply-To: (Maxim Blinov's message of "Tue, 3 Mar 2020 14:52:45 +0000") Message-ID: <87zhcw8nvt.fsf@oldenburg2.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes X-SW-Source: 2020-03/txt/msg00006.txt * Maxim Blinov: > I'm looking at some -fstack-check'ed code, and would appreciate it if > some gdb x86_64 gurus could double check my understanding of a trivial > example What's your motivation for this? -fstack-check is mostly there to support certain Ada uses, yet you post a C snippet. The more generally useful stack overflow detection switch is called -fstack-clash-protection. Thanks, Florian