From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5524 invoked by alias); 9 May 2014 10:10:04 -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 5508 invoked by uid 89); 9 May 2014 10:10:03 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 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; Fri, 09 May 2014 10:10:01 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s49AA0DH022628 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 9 May 2014 06:10:00 -0400 Received: from blade.nx (ovpn-116-96.ams2.redhat.com [10.36.116.96]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s49A9xZu029457 for ; Fri, 9 May 2014 06:10:00 -0400 Received: by blade.nx (Postfix, from userid 1000) id 3DCF626234A; Fri, 9 May 2014 11:09:59 +0100 (BST) Date: Fri, 09 May 2014 10:10:00 -0000 From: Gary Benson To: gdb-patches@sourceware.org Subject: [PATCH 2/2] Demangler crash handler Message-ID: <20140509100959.GC4760@blade.nx> References: <20140509100656.GA4760@blade.nx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140509100656.GA4760@blade.nx> X-IsSubscribed: yes X-SW-Source: 2014-05/txt/msg00110.txt.bz2 This patch wraps calls to the demangler with a segmentation fault handler. A warning is printed the first time a segmentation fault is caught. gdb/ 2014-05-09 Gary Benson PR backtrace/16817 * cp-support.c (signal.h): New include. (gdb_demangle_signal_handler): New function. (gdb_demangle): Install the above signal handler before calling bfd_demangle, and restore the original signal handler afterwards. gdb/testsuite/ 2014-05-09 Gary Benson PR backtrace/16817 * gdb.base/pr16817.exp: New file. diff --git a/gdb/cp-support.c b/gdb/cp-support.c index 91533e8..f1a0d49 100644 --- a/gdb/cp-support.c +++ b/gdb/cp-support.c @@ -36,6 +36,7 @@ #include "value.h" #include "cp-abi.h" #include "language.h" +#include #include "safe-ctype.h" @@ -1505,12 +1506,71 @@ cp_lookup_rtti_type (const char *name, struct block *block) return rtti_type; } +/* Signal handler for gdb_demangle. */ + +static void +gdb_demangle_signal_handler (int signo) +{ + throw_error (GENERIC_ERROR, _("demangler failed with signal %d"), + signo); +} + /* A wrapper for bfd_demangle. */ char * gdb_demangle (const char *name, int options) { - return bfd_demangle (NULL, name, options); + char *result = NULL; + +#ifdef SIGSEGV + volatile struct gdb_exception except; + +#if defined (HAVE_SIGACTION) && defined (SA_RESTART) + struct sigaction sa, old_sa; + + sa.sa_handler = gdb_demangle_signal_handler; + sigemptyset (&sa.sa_mask); + sa.sa_flags = 0; + sigaction (SIGSEGV, &sa, &old_sa); +#else + void (*ofunc) (); + + ofunc = (void (*)()) signal (SIGSEGV, gdb_demangle_signal_handler); +#endif +#endif + + TRY_CATCH (except, RETURN_MASK_ALL) + { + result = bfd_demangle (NULL, name, options); + } + +#ifdef SIGSEGV +#if defined (HAVE_SIGACTION) && defined (SA_RESTART) + sigaction (SIGSEGV, &old_sa, NULL); +#else + signal (SIGSEGV, ofunc); +#endif +#endif + + if (except.reason < 0) + { + static int warning_printed = 0; + + if (!warning_printed) + { + warning ("internal error: %s\n" + "Unable to demangle '%s'\n" + "This is a bug, " + "please report it to the GDB maintainers.", + except.message, name); + + warning_printed = 1; + } + + result = NULL; + } + + return result; } /* Don't allow just "maintenance cplus". */ diff --git a/gdb/testsuite/gdb.base/pr16817.exp b/gdb/testsuite/gdb.base/pr16817.exp new file mode 100644 index 0000000..fff022c --- /dev/null +++ b/gdb/testsuite/gdb.base/pr16817.exp @@ -0,0 +1,25 @@ +# Copyright 2014 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# Test that a segmentation fault in the demangler does not cause GDB +# to crash. If the demangler becomes able to demangle the below +# symbol then another symbol will need to be found for this test. + +set symbol "_QueueNotification_QueueController__\$4PPPPPPPM_A_INotice___Z" + +gdb_exit +gdb_start +gdb_test_no_output "set lang c++" +gdb_test "maint demangle $symbol" ".*demangler failed.*"