From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21805 invoked by alias); 13 Jan 2015 14:43:58 -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 21795 invoked by uid 89); 13 Jan 2015 14:43:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.2 X-HELO: goliath.siemens.de Received: from goliath.siemens.de (HELO goliath.siemens.de) (192.35.17.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Tue, 13 Jan 2015 14:43:51 +0000 Received: from mail2.siemens.de (localhost [127.0.0.1]) by goliath.siemens.de (8.14.3/8.14.3) with ESMTP id t0DEheQs009026; Tue, 13 Jan 2015 15:43:40 +0100 Received: from md1f2u6c.ww002.siemens.net (md1f2u6c.mch.sbs.de [139.25.40.156] (may be forged)) by mail2.siemens.de (8.14.3/8.14.3) with ESMTP id t0DEhd6Q017974; Tue, 13 Jan 2015 15:43:40 +0100 Message-ID: <54B52F1A.5040509@siemens.com> Date: Tue, 13 Jan 2015 14:43:00 -0000 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Joel Brobecker CC: gdb@sourceware.org, Pedro Alves Subject: Re: python-injected silent breakpoints broken since 1a853c52 References: <54B52A1B.1090409@siemens.com> <20150113143935.GI8139@adacore.com> In-Reply-To: <20150113143935.GI8139@adacore.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-01/txt/msg00020.txt.bz2 On 2015-01-13 15:39, Joel Brobecker wrote: > Jan, > >> I've stumbled over a regression of gdb since commit 1a853c52 (make >> "permanent breakpoints" per location and disableable). My gdb python >> scripts [1] that load Linux kernel module symbols as the target loads >> the modules now fail. >> >> The involved command is lx-symbols [2]. It installs a silent breakpoint >> on a kernel function that is called when a module is loaded. Before >> 1a853c52, the python callback was normally invoked and the target >> continued to run. Since af48d08f (1a853c52 is not testable), the int3 >> instruction (I'm testing with x86) is left in the target, and garbage >> instructions are executed, causing a kernel oops. The breakpoint is >> apparently not properly skipped (remove, single-step, re-insert) when >> resuming the target on return from LoadModuleBreakpoint.stop(). >> >> I can provide more details on how to set up a reproduction case but I >> would only gather them when desired as that is not straightforward. >> >> Jan >> >> [1] https://lkml.org/lkml/2014/11/20/531 >> [2] >> http://git.kiszka.org/?p=linux.git;a=blob;f=scripts/gdb/linux/symbols.py;h=bf05e451c58666add299061046bf1ceb9e82f4ef;hb=d92098e7cf60d31ccd025e56d20c23917ccd0819 > > Thanks for the report! > > Can you please open a PR at the following URL? > https://sourceware.org/bugzilla/ > > There is a chance that we might consider this regression as > release blocking for GDB 7.9 (planned for the near future), > and having PR makes things a lot easier to track. Done: https://sourceware.org/bugzilla/show_bug.cgi?id=17837 Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux