From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 73510 invoked by alias); 11 Apr 2018 02:46:28 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 73496 invoked by uid 89); 11 Apr 2018 02:46:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy=acknowledgement X-HELO: smtp.polymtl.ca Received: from smtp.polymtl.ca (HELO smtp.polymtl.ca) (132.207.4.11) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 11 Apr 2018 02:46:26 +0000 Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id w3B2kKDK032229 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 10 Apr 2018 22:46:24 -0400 Received: by simark.ca (Postfix, from userid 112) id 382391EF62; Tue, 10 Apr 2018 22:46:20 -0400 (EDT) Received: from simark.ca (localhost [127.0.0.1]) by simark.ca (Postfix) with ESMTP id C04271E47D; Tue, 10 Apr 2018 22:46:17 -0400 (EDT) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 11 Apr 2018 02:46:00 -0000 From: Simon Marchi To: Omair Javaid Cc: Yao Qi , GDB Patches , Pedro Alves Subject: Re: [PATCH 0/3 v3] [AArch64] Support tagged pointer In-Reply-To: References: <1512727471-30745-1-git-send-email-yao.qi@linaro.org> Message-ID: <949e7a0c9b7fa2bdffa7cc0b9ee6132c@polymtl.ca> X-Sender: simon.marchi@polymtl.ca User-Agent: Roundcube Webmail/1.3.4 X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Wed, 11 Apr 2018 02:46:20 +0000 X-IsSubscribed: yes X-SW-Source: 2018-04/txt/msg00207.txt.bz2 On 2018-04-10 20:36, Omair Javaid wrote: >> This patch has broken kernel debugging using kgdb and openOCD. >> >> Tagged address should only be considered while debugging only >> user-space >> programs on linux. >> >> I still need to understand the full background behind this patch but >> can >> we pull it out of 8.1 release to make sure kernel debugging works? >> >> > Just found out that patch series posted here > https://sourceware.org/ml/gdb-patches/2017-12/msg00160.html does change > aarch64-linux-tdep only. > But the committed version here > https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=a738ea1d41daeec0cccb4ab6671f4f6d53bd9e18 > is > applying it to aarch64-tdep I think it was because of Pedro's suggestion in this reply: https://sourceware.org/ml/gdb-patches/2017-12/msg00179.html although there was now acknowledgement from Yao, so I can only guess. As Pedro said, it's the hardware that ignores these top bits. But it first has to be configured to do so, so we can't assume that all aarch64 code behaves like this. So far we only know that the Linux userspace threads work like that, so I think it would make sense to move it to aarch64-linux-tdep.c. Did you confirm that it indeed fixes your problem? I could see a fix for this getting into the 8.1 branch (not reverting the patch though). Simon