From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30255 invoked by alias); 21 Nov 2004 05:19:41 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 30216 invoked from network); 21 Nov 2004 05:19:32 -0000 Received: from unknown (HELO legolas.inter.net.il) (192.114.186.24) by sourceware.org with SMTP; 21 Nov 2004 05:19:32 -0000 Received: from zaretski ([80.230.143.196]) by legolas.inter.net.il (MOS 3.5.5-GR) with ESMTP id DDU54405 (AUTH halo1); Sun, 21 Nov 2004 07:18:52 +0200 (IST) Date: Sun, 21 Nov 2004 05:19:00 -0000 From: "Eli Zaretskii" To: David Lecomber Message-ID: <01c4cf89$Blat.v2.2.2$616cb580@zahav.net.il> Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=ISO-8859-1 CC: drow@false.org, gdb-patches@sources.redhat.com In-reply-to: <1100996751.22991.39.camel@cpc2-oxfd5-5-0-cust91.oxfd.cable.ntl.com> (message from David Lecomber on Sun, 21 Nov 2004 00:25:51 +0000) Subject: Re: [PATCH] Seg fault whilst stepping when watch set [ping!] [in breakpoint.c] Reply-to: Eli Zaretskii References: <01c4cef8$Blat.v2.2.2$3fd12960@zahav.net.il> <1100996751.22991.39.camel@cpc2-oxfd5-5-0-cust91.oxfd.cable.ntl.com> X-SW-Source: 2004-11/txt/msg00424.txt.bz2 > From: David Lecomber > Cc: Daniel Jacobowitz , patches > Date: Sun, 21 Nov 2004 00:25:51 +0000 > > > Also, last time we talked, I asked whether this could be due to the > > Fedora exec-shield feature, but didn't see any response to that. > > Could you please check that? > > I'm not sure how to verify that one There should be a way to switch exec-shield off, but I don't know how. I meant to ask you to see if switching it off makes the problem go away. > Thanks for looking at this bug, here's the latest stack trace and > session log for current CVS: Thanks, there seems to be a different problem (or maybe several problems): > (gdb) b f90demo.f90 : 41 > During symbol reading, unsupported tag: 'DW_TAG_module'. > During symbol reading, Attribute value is not a constant > (DW_FORM_block1). > [...] > (gdb) watch i > During symbol reading, incomplete CFI data; unspecified registers (e.g., > eax) at 0x804bc35. Can someone please explain what do these messages mean, in the context of the problem at hand, and why didn't David report them in a previous GDB version? Did the same problems happen in the older GDB as well, but were just silently ignored, or are we looking at a completely different cause for a segfault? Also, David, I asked you to check why doesn't GDB segfault when it evaluates the same expression on line 1142, before calling insert_bp_location. > I know the patch I originally suggested could be a cure of the symptom, > rather than the cause - but as it's harmless, if we can't figure out why > it happens, it could be worth just committing anyway: all the patch does > is check a value is non-null, and if so takes action - without the patch > such a scenario will always segfault! Sorry, I'm reluctant to approve a patch that fixes a problem that we are unable to understand. It's not clean.