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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 29C28385829E for ; Tue, 14 Jun 2022 04:07:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 29C28385829E Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-635-dzz-B-snPs6IQoluj9VkSA-1; Tue, 14 Jun 2022 00:07:48 -0400 X-MC-Unique: dzz-B-snPs6IQoluj9VkSA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BC631101A54E; Tue, 14 Jun 2022 04:07:47 +0000 (UTC) Received: from greed.delorie.com (unknown [10.22.8.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A783E1121314; Tue, 14 Jun 2022 04:07:47 +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 25E47lwQ4058331; Tue, 14 Jun 2022 00:07:47 -0400 From: DJ Delorie To: Noah Goldstein Cc: hjl.tools@gmail.com, libc-alpha@sourceware.org Subject: Re: [patch/idea] Add register scrambling to testsuite In-Reply-To: Date: Tue, 14 Jun 2022 00:07:47 -0400 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, 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 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: , X-List-Received-Date: Tue, 14 Jun 2022 04:07:57 -0000 Noah Goldstein writes: > Once this is in we can just throw in a `vzeroall`. As long as it doesn't zero all the registers, which is what blinded the testcase that triggered this. Oh wait... Ideally we'd want to fill all registers with a large-ish constant that isn't a valid pointer, like 0x13579bdf. "obviously wrong" is the goal.