From patchwork Wed Aug 23 17:36:08 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergio Durigan Junior X-Patchwork-Id: 22336 Received: (qmail 85705 invoked by alias); 23 Aug 2017 17:36:18 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 84142 invoked by uid 89); 23 Aug 2017 17:36:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-25.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_LAZY_DOMAIN_SECURITY, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=instruct 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; Wed, 23 Aug 2017 17:36:15 +0000 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E52DC1840 for ; Wed, 23 Aug 2017 17:36:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E52DC1840 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=sergiodj@redhat.com Received: from psique.yyz.redhat.com (unused-10-15-17-193.yyz.redhat.com [10.15.17.193]) by smtp.corp.redhat.com (Postfix) with ESMTP id BAC2360483; Wed, 23 Aug 2017 17:36:11 +0000 (UTC) From: Sergio Durigan Junior To: GDB Patches Cc: Pedro Alves , Sergio Durigan Junior Subject: [PATCH] Fix PR remote/21852: Remote run without specifying a local binary crashes GDB Date: Wed, 23 Aug 2017 13:36:08 -0400 Message-Id: <20170823173608.17654-1-sergiodj@redhat.com> In-Reply-To: <3ef5d58f-6d27-8f07-b45d-db7f883837a4@redhat.com> References: <3ef5d58f-6d27-8f07-b45d-db7f883837a4@redhat.com> X-IsSubscribed: yes There is an assertion that is triggering when we start GDB and instruct it to debug a remote inferior, but don't provide a local binary, like: ./gdb -nx -q --data-directory=data-directory -ex "tar ext :1234" \ -ex "set remote exec-file /bin/ls" -ex r In this case, when calling exec_file_locate_attach to locate the inferior, GDB is incorrectly resetting the breakpoints without a thread/inferior even running, which causes an assertion to be triggered: binutils-gdb/gdb/thread.c:1609: internal-error: scoped_restore_current_thread::scoped_restore_current_thread(): Assertion `tp != NULL' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) This happens because add_current_inferior_and_thread (on remote.c) is breaking an invariant: making inferior_ptid point to a non-existing thread and then calling common code, which in this case is breakpoint_re_set. The fix is to make sure that inferior_ptid points to null_ptid if there is no thread present. A testcase is provided. Regtested on buildbot. gdb/ChangeLog: 2017-08-23 Pedro Alvex PR remote/21852 * remote.c (add_current_inferior_and_thread): Set inferior_ptid to null_ptid and switch to thread without reading the registers after adding the inferior. gdb/testsuite/ChangeLog: 2017-08-23 Sergio Durigan Junior PR remote/21852 * gdb.server/normal.c: New file, copied from gdb.base. * gdb.server/run-without-local-binary.exp: New file. --- gdb/remote.c | 18 +++---- gdb/testsuite/gdb.server/normal.c | 24 +++++++++ .../gdb.server/run-without-local-binary.exp | 60 ++++++++++++++++++++++ 3 files changed, 93 insertions(+), 9 deletions(-) create mode 100644 gdb/testsuite/gdb.server/normal.c create mode 100644 gdb/testsuite/gdb.server/run-without-local-binary.exp diff --git a/gdb/remote.c b/gdb/remote.c index ff59a0f81f..2249533258 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -3831,19 +3831,16 @@ add_current_inferior_and_thread (char *wait_status) { struct remote_state *rs = get_remote_state (); int fake_pid_p = 0; - ptid_t ptid; inferior_ptid = null_ptid; /* Now, if we have thread information, update inferior_ptid. */ - ptid = get_current_thread (wait_status); + ptid_t curr_ptid = get_current_thread (wait_status); - if (!ptid_equal (ptid, null_ptid)) + if (curr_ptid != null_ptid) { if (!remote_multi_process_p (rs)) fake_pid_p = 1; - - inferior_ptid = ptid; } else { @@ -3851,14 +3848,17 @@ add_current_inferior_and_thread (char *wait_status) (such as kill) won't work. This variable serves (at least) double duty as both the pid of the target process (if it has such), and as a flag indicating that a target is active. */ - inferior_ptid = magic_null_ptid; + curr_ptid = magic_null_ptid; fake_pid_p = 1; } - remote_add_inferior (fake_pid_p, ptid_get_pid (inferior_ptid), -1, 1); + remote_add_inferior (fake_pid_p, ptid_get_pid (curr_ptid), -1, 1); - /* Add the main thread. */ - add_thread_silent (inferior_ptid); + /* Add the main thread and switch to it. Don't try reading + registers yet, since we haven't fetched the target description + yet. */ + thread_info *tp = add_thread_silent (curr_ptid); + switch_to_thread_no_regs (tp); } /* Print info about a thread that was found already stopped on diff --git a/gdb/testsuite/gdb.server/normal.c b/gdb/testsuite/gdb.server/normal.c new file mode 100644 index 0000000000..f0eb1541fd --- /dev/null +++ b/gdb/testsuite/gdb.server/normal.c @@ -0,0 +1,24 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2013-2017 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 . */ + +/* This test is just a normal return 0. */ + +int +main (int argc, char *argv[]) +{ + return 0; +} diff --git a/gdb/testsuite/gdb.server/run-without-local-binary.exp b/gdb/testsuite/gdb.server/run-without-local-binary.exp new file mode 100644 index 0000000000..ea4b043a7a --- /dev/null +++ b/gdb/testsuite/gdb.server/run-without-local-binary.exp @@ -0,0 +1,60 @@ +# Copyright 2017 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 . */ + +load_lib gdbserver-support.exp + +if {[skip_gdbserver_tests]} { + return +} + +standard_testfile normal.c + +if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} { + return -1 +} + +# Test running GDB without providing a local binary for it. In order +# to do that, we unset GDBFLAGS before running GDB. We also start +# gdbserver "by hand". For more details about this test, see PR +# remote/21852. +save_vars { GDBFLAGS } { + set GDBFLAGS "" + gdb_exit + gdb_start + + gdb_test_no_output "set remote exec-file $binfile" \ + "set remote exec-file" + + # Make sure we're disconnected, in case we're testing with an + # extended-remote board, therefore already connected. + gdb_test "disconnect" ".*" "disconnect" + + # Let's start gdbserver in extended-remote mode now. + set res [gdbserver_start "--multi" ""] + set gdbserver_protocol [lindex $res 0] + if { [string first "extended-" $gdbserver_protocol] != 0} { + set gdbserver_protocol "extended-$gdbserver_protocol" + } + set gdbserver_gdbport [lindex $res 1] + set use_gdb_stub 0 + + gdb_test "target ${gdbserver_protocol} ${gdbserver_gdbport}" \ + "Remote debugging using $gdbserver_gdbport" \ + "connect to gdbserver" + + gdb_test "run" \ + "\\\[Inferior $decimal \\\(process $decimal\\\) exited normally\\\]" \ + "run test program until the end" +}