From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20739 invoked by alias); 15 Mar 2013 19:55:15 -0000 Received: (qmail 20730 invoked by uid 22791); 15 Mar 2013 19:55:14 -0000 X-SWARE-Spam-Status: No, hits=-7.4 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_SPAMHAUS_DROP,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 15 Mar 2013 19:54:59 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r2FJsvjx004091 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 15 Mar 2013 15:54:57 -0400 Received: from host2.jankratochvil.net (ovpn-116-42.ams2.redhat.com [10.36.116.42]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r2FJspxA006922 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Fri, 15 Mar 2013 15:54:54 -0400 Date: Fri, 15 Mar 2013 22:29:00 -0000 From: Jan Kratochvil To: Yao Qi Cc: gdb-patches@sourceware.org, "Metzger, Markus T" Subject: Re: [patch] Fix remote.c incorrectly using pop_target (wrt btrace) Message-ID: <20130315195451.GB19841@host2.jankratochvil.net> References: <20130311172836.GA22575@host2.jankratochvil.net> <513EFD81.6050401@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <513EFD81.6050401@codesourcery.com> User-Agent: Mutt/1.5.21 (2010-09-15) 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: 2013-03/txt/msg00693.txt.bz2 On Tue, 12 Mar 2013 11:03:45 +0100, Yao Qi wrote: > On 03/12/2013 01:28 AM, Jan Kratochvil wrote: > >@@ -4348,7 +4344,7 @@ remote_open_1 (char *name, int from_tty, > > /* Pop the partially set up target - unless something else did > > already before throwing the exception. */ > > if (remote_desc != NULL) > >- pop_target (); > >+ remote_unpush_target (); > > Since it is in remote_open_1, the remote target or exteneded-remote > target is just pushed and top most, so pop_target should be fine > here. It is not necessary to change it to remote_unpush_target. OK; but one should remove pop_target later, there remain only few uses of it. When its use is not incorrect it is at least fragile/dangerous. > Is it what we want? When GDB is in record-btrace target, and get > some errors in communication, both record-btrace and remote target > should be popped from the stack. It causes on killed gdbserver: (gdb) stepi You can't do that when your target is `record-btrace' (gdb) _ As btrace target then no longer has methods it expects underneath. So I have changed remote_unpush_target below. Testing of this patch generally requires: [patch+7.6] Fix 7.5 regression crashing GDB if gdbserver dies http://sourceware.org/ml/gdb-patches/2013-03/msg00691.html Message-ID: <20130315195359.GA19841@host2.jankratochvil.net> No regressions on {x86_64,x86_64-m32,i686}-fedora19pre-linux-gnu and with gdbserver. Thanks, Jan gdb/ 2013-03-15 Jan Kratochvil * remote.c (remote_unpush_target): New function. (remote_open_1): Remove two pop_target calls, update one comment, add comment to target_preopen call. Replace pop_target call by remote_unpush_target call. (interrupt_query, readchar, getpkt_or_notif_sane_1): Replace pop_target calls by remote_unpush_target calls. diff --git a/gdb/remote.c b/gdb/remote.c index 21d86f7..207180d 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -4188,6 +4188,14 @@ remote_query_supported (void) } } +/* Remove any of the remote.c targets from target stack. Upper targets depend + on it so remove them first. */ + +static void +remote_unpush_target (void) +{ + pop_all_targets_above (process_stratum - 1, 0); +} static void remote_open_1 (char *name, int from_tty, @@ -4205,30 +4213,18 @@ remote_open_1 (char *name, int from_tty, wait_forever_enabled_p = 1; /* If we're connected to a running target, target_preopen will kill it. - But if we're connected to a target system with no running process, - then we will still be connected when it returns. Ask this question - first, before target_preopen has a chance to kill anything. */ + Ask this question first, before target_preopen has a chance to kill + anything. */ if (remote_desc != NULL && !have_inferiors ()) { - if (!from_tty - || query (_("Already connected to a remote target. Disconnect? "))) - pop_target (); - else + if (from_tty + && !query (_("Already connected to a remote target. Disconnect? "))) error (_("Still connected.")); } + /* Here the possibly existing remote target gets unpushed. */ target_preopen (from_tty); - unpush_target (target); - - /* This time without a query. If we were connected to an - extended-remote target and target_preopen killed the running - process, we may still be connected. If we are starting "target - remote" now, the extended-remote target will not have been - removed by unpush_target. */ - if (remote_desc != NULL && !have_inferiors ()) - pop_target (); - /* Make sure we send the passed signals list the next time we resume. */ xfree (last_pass_packet); last_pass_packet = NULL; @@ -4348,7 +4344,7 @@ remote_open_1 (char *name, int from_tty, /* Pop the partially set up target - unless something else did already before throwing the exception. */ if (remote_desc != NULL) - pop_target (); + remote_unpush_target (); if (target_async_permitted) wait_forever_enabled_p = 1; throw_exception (ex); @@ -5096,7 +5092,7 @@ interrupt_query (void) if (query (_("Interrupted while waiting for the program.\n\ Give up (and stop debugging it)? "))) { - pop_target (); + remote_unpush_target (); deprecated_throw_reason (RETURN_QUIT); } } @@ -7051,11 +7047,11 @@ readchar (int timeout) switch ((enum serial_rc) ch) { case SERIAL_EOF: - pop_target (); + remote_unpush_target (); error (_("Remote connection closed")); /* no return */ case SERIAL_ERROR: - pop_target (); + remote_unpush_target (); perror_with_name (_("Remote communication error. " "Target disconnected.")); /* no return */ @@ -7579,7 +7575,7 @@ getpkt_or_notif_sane_1 (char **buf, long *sizeof_buf, int forever, if (forever) /* Watchdog went off? Kill the target. */ { QUIT; - pop_target (); + remote_unpush_target (); error (_("Watchdog timeout has expired. Target detached.")); } if (remote_debug)