From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5635 invoked by alias); 3 Nov 2011 17:37:03 -0000 Received: (qmail 5556 invoked by uid 22791); 3 Nov 2011 17:37:02 -0000 X-SWARE-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_NONE X-Spam-Check-By: sourceware.org Received: from caibbdcaaaaf.dreamhost.com (HELO homiemail-a80.g.dreamhost.com) (208.113.200.5) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 03 Nov 2011 17:36:47 +0000 Received: from homiemail-a80.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a80.g.dreamhost.com (Postfix) with ESMTP id 31B7237A076; Thu, 3 Nov 2011 10:36:47 -0700 (PDT) Received: from redwood.eagercon.com (c-76-102-3-160.hsd1.ca.comcast.net [76.102.3.160]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: eager@eagerm.com) by homiemail-a80.g.dreamhost.com (Postfix) with ESMTPSA id 019FF37A06E; Thu, 3 Nov 2011 10:36:46 -0700 (PDT) Message-ID: <4EB2D12E.2010900@eagerm.com> Date: Thu, 03 Nov 2011 17:37:00 -0000 From: Michael Eager User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0) Gecko/20110927 Thunderbird/7.0 MIME-Version: 1.0 To: Jan Kratochvil CC: Tom Tromey , "gdb-patches@sourceware.org" Subject: Re: SEGV in dwarf2read.c -- gdb-7.2 References: <4EB2BD58.3080003@eagerm.com> <20111103162026.GA12269@host1.jankratochvil.net> <20111103165521.GA16221@host1.jankratochvil.net> <4EB2CBA0.7030307@eagerm.com> <20111103172232.GA23268@host1.jankratochvil.net> In-Reply-To: <20111103172232.GA23268@host1.jankratochvil.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes 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 X-SW-Source: 2011-11/txt/msg00089.txt.bz2 On 11/03/2011 10:22 AM, Jan Kratochvil wrote: > On Thu, 03 Nov 2011 18:13:04 +0100, Michael Eager wrote: >> With the addition of the call to age_cached_comp_units() in >> dwarf2_fetch_die_location_block() and dw2_do_instantiate_symtab(), >> I think that the cache is aged very aggressively. > >> With dwarf2_max_cache_age == 5, it looks to me that it is likely that CU >> data will not be in the cache when needed. > > There was for example this fix: > http://sourceware.org/ml/gdb-patches/2011-07/msg00495.html > > which is not yet even in 7.3.1 as I see now, it is only in FSF GDB HEAD. Thanks. The patch looks similar to the one I came up with. I added a similar check higher in the call tree. > wrt CUs aging therefore only FSF GDB HEAD matters, older releases are known to > be buggy - at least due to this bug. > > With FSF GDB HEAD I am not aware of any problems because any call to > age_cached_comp_units is done when CUs are no longer needed anywhere. > > I do not discuss here about efficiency of the FSF GDB HEAD solution but I am > not aware of how it could crash any way. I'll see if it works with my application. -- Michael Eager eager@eagercon.com 1960 Park Blvd., Palo Alto, CA 94306 650-325-8077