From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 96327 invoked by alias); 4 Sep 2019 21:36:50 -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 96319 invoked by uid 89); 4 Sep 2019 21:36:49 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-3.6 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 04 Sep 2019 21:36:48 +0000 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B9B75877A6D; Wed, 4 Sep 2019 21:36:46 +0000 (UTC) Received: from localhost (unused-10-15-17-196.yyz.redhat.com [10.15.17.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8CF2960852; Wed, 4 Sep 2019 21:36:46 +0000 (UTC) From: Sergio Durigan Junior To: Pedro Alves Cc: GDB Patches , Eli Zaretskii , Ruslan Kabatsayev Subject: Re: [PATCH v2] Improve ptrace-error detection on Linux targets References: <20190819032918.3536-1-sergiodj@redhat.com> <20190826183205.19008-1-sergiodj@redhat.com> <28c4f743-91f1-59c3-83ff-3f791811f996@redhat.com> <87mufrai1z.fsf@redhat.com> <87zhjjrh7n.fsf@redhat.com> <87d0gfrewj.fsf@redhat.com> <587b2e6b-15ec-0ba1-f425-82ec45eb4ca7@redhat.com> <875zm7rd9v.fsf@redhat.com> <8b3979cd-8c24-42e0-334b-de02cda2b799@redhat.com> Date: Wed, 04 Sep 2019 21:36:00 -0000 In-Reply-To: <8b3979cd-8c24-42e0-334b-de02cda2b799@redhat.com> (Pedro Alves's message of "Wed, 4 Sep 2019 22:23:30 +0100") Message-ID: <871rwvrbf5.fsf@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-IsSubscribed: yes X-SW-Source: 2019-09/txt/msg00046.txt.bz2 On Wednesday, September 04 2019, Pedro Alves wrote: > On 9/4/19 9:56 PM, Sergio Durigan Junior wrote: >>> You could start gdbserver with the restrictions off (like a long >>> lived daemon), and then while gdbserver is running enable >>> restrictions, I suppose. >> Ah, right, I think that would also work. > > I'm interested in knowing whether the error percolates to > the gdb side in a reasonable form. The attach error is displayed by GDB, but the information about ptrace restrictions is not. This is what I see on GDB: (gdb) attach 32378 Attaching to process 32378 Attaching to process 32378 failed And this is what I see on gdbserver: gdbserver: Cannot attach to process 32378: Permission denied (13), the SELinux boolean 'deny_ptrace' is enabled, you can disable this process attach protection by: (gdb) shell sudo setsebool deny_ptrace=0 I think there's something wrong with the terminal settings because newlines aren't being respected here. But the message is still there, and the user can still understand it, I think. Ideally we'd have GDB also display the ptrace restriction warning, but I think that if the user can see that the attach failed, she will likely look at what happened with gdbserver, and will see the error there. If we were to show the message on GDB, we'd also have to rewrite it in a way that explains that the command needs to be run at the target, which may confuse things. Thanks, -- Sergio GPG key ID: 237A 54B1 0287 28BF 00EF 31F4 D0EB 7628 65FC 5E36 Please send encrypted e-mail if possible http://sergiodj.net/