From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-patches-return-84133-listarch-gdb-patches=sources.redhat.com@sourceware.org>
Received: (qmail 18582 invoked by alias); 5 Oct 2011 14:07:18 -0000
Received: (qmail 18569 invoked by uid 22791); 5 Oct 2011 14:07:16 -0000
X-SWARE-Spam-Status: No, hits=-2.6 required=5.0	tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,T_TO_NO_BRKTS_FREEMAIL
X-Spam-Check-By: sourceware.org
Received: from mail-ww0-f43.google.com (HELO mail-ww0-f43.google.com) (74.125.82.43)    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 05 Oct 2011 14:06:42 +0000
Received: by wwf27 with SMTP id 27so2044749wwf.12        for <gdb-patches@sourceware.org>; Wed, 05 Oct 2011 07:06:41 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.227.10.136 with SMTP id p8mr3263285wbp.41.1317823600939; Wed, 05 Oct 2011 07:06:40 -0700 (PDT)
Received: by 10.180.84.162 with HTTP; Wed, 5 Oct 2011 07:06:40 -0700 (PDT)
Date: Wed, 05 Oct 2011 14:07:00 -0000
Message-ID: <CAF4KFGogYaeRzr6_i8fcGhO-SPr3eSdyppxVha57R_sqo2s1ng@mail.gmail.com>
Subject: A fix for bug 13259 - gdb sometimes crashes with SIGSEGV when printing variables
From: Martin Runge <martin.runge@web.de>
To: gdb-patches@sourceware.org
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
X-IsSubscribed: yes
Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb-patches.sourceware.org>
List-Subscribe: <mailto:gdb-patches-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb-patches/>
List-Post: <mailto:gdb-patches@sourceware.org>
List-Help: <mailto:gdb-patches-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-patches-owner@sourceware.org
X-SW-Source: 2011-10/txt/msg00136.txt.bz2

Hello together,
here is a possible fix for a gdb crash I just filed as bug 13259:


--- a/gdb/varobj.c =C2=A0 =C2=A0 =C2=A0Wed Sep 28 12:36:27 2011 +0200
+++ b/gdb/varobj.c =C2=A0 =C2=A0 =C2=A0Wed Oct 05 15:53:04 2011 +0200
@@ -2640,7 +2640,7 @@
=C2=A0 =C2=A0opts.raw =3D 1;
=C2=A0 =C2=A0if (thevalue)
=C2=A0 =C2=A0 =C2=A0LA_PRINT_STRING (stb, type, thevalue, len, encoding, 0,=
 &opts);
- =C2=A0else if (string_print)
+ =C2=A0else if (string_print && type !=3D NULL)
=C2=A0 =C2=A0 =C2=A0val_print_string (type, encoding, str_addr, len, stb, &=
opts);
=C2=A0 =C2=A0else
=C2=A0 =C2=A0 =C2=A0common_val_print (value, stb, 0, &opts, current_languag=
e);


I observed the "type" parameter beeing NULL _and_ "string_print" !=3D0
several times, which leads to a SIGSEGV inside val_print_string.

Maybe the cause is a few lines earlier in the same function
(value_get_print_value), where string_print is set to 1 without having
resolved "type".

best regards
Martin