From FEDORA_PATCHES Mon Sep 17 00:00:00 2001 From: Fedora GDB patches Date: Fri, 27 Oct 2017 21:07:50 +0200 Subject: gdb-bz1219747-attach-kills.patch ;; Never kill PID on: gdb exec PID (Jan Kratochvil, RH BZ 1219747). ;;=push+jan http://sourceware.org/ml/gdb-patches/2015-10/msg00301.html Hi, in some cases with deleted main executable GDB will want to kill the inferior. $ cp /bin/sleep /tmp/sleep;/tmp/sleep 1h&p=$! $ rm /tmp/sleep $ gdb /tmp/sleep $p GNU gdb (GDB) 7.10.50.20151016-cvs /tmp/sleep: No such file or directory. Attaching to process 9694 /tmp/sleep (deleted): No such file or directory. A program is being debugged already. Kill it? (y or n) _ The first attachment of "/tmp/sleep" commandline argument errors at: 267 if (scratch_chan < 0) 268 perror_with_name (filename); 1051 if (catch_command_errors_const (exec_file_attach, execarg, 1052 !batch_flag)) Then GDB tries to attach to the process $p: 1082 if (catch_command_errors (attach_command, pid_or_core_arg, 1083 !batch_flag) == 0) This succeeds and since this moment GDB has a valid inferior. But despite that the lines 1082 if (catch_command_errors (attach_command, pid_or_core_arg, 1083 !batch_flag) == 0) still fail because consequently attach_command() fails to find the associated executable file: 267 if (scratch_chan < 0) 268 perror_with_name (filename); 1082 if (catch_command_errors (attach_command, pid_or_core_arg, 1083 !batch_flag) == 0) and therefore GDB executes the following: (gdb) bt 2179 if (have_inferiors ()) 2180 { 2181 if (!from_tty 2182 || !have_live_inferiors () 2183 || query (_("A program is being debugged already. Kill it? "))) 2184 iterate_over_inferiors (dispose_inferior, NULL); 2185 else 2186 error (_("Program not killed.")); 2187 } 1084 catch_command_errors (core_file_command, pid_or_core_arg, 1085 !batch_flag); No regressions on {x86_64,x86_64-m32,i686}-fedora24pre-linux-gnu. Thanks, Jan gdb/ChangeLog 2015-10-16 Jan Kratochvil * main.c (captured_main): Run core_file_command for pid_or_core_arg only if not have_inferiors (). gdb/testsuite/ChangeLog 2015-10-16 Jan Kratochvil * gdb.base/attach-kills.c: New. * gdb.base/attach-kills.exp: New. diff --git a/gdb/main.c b/gdb/main.c --- a/gdb/main.c +++ b/gdb/main.c @@ -1199,7 +1199,10 @@ captured_main_1 (struct captured_main_args *context) { ret = catch_command_errors (attach_command, pid_or_core_arg, !batch_flag); - if (ret == 0) + if (ret == 0 + /* attach_command could succeed partially and core_file_command + would try to kill it. */ + && !have_inferiors ()) ret = catch_command_errors (core_file_command, pid_or_core_arg, !batch_flag); diff --git a/gdb/testsuite/gdb.base/attach-kills.c b/gdb/testsuite/gdb.base/attach-kills.c new file mode 100644 --- /dev/null +++ b/gdb/testsuite/gdb.base/attach-kills.c @@ -0,0 +1,25 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2015 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 . */ + +#include + +int +main (void) +{ + sleep (600); + return 0; +} diff --git a/gdb/testsuite/gdb.base/attach-kills.exp b/gdb/testsuite/gdb.base/attach-kills.exp new file mode 100644 --- /dev/null +++ b/gdb/testsuite/gdb.base/attach-kills.exp @@ -0,0 +1,49 @@ +# Copyright (C) 2015 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 . + +if { ![can_spawn_for_attach] } { + return 0 +} + +standard_testfile + +if { [build_executable ${testfile}.exp $testfile] == -1 } { + return -1 +} + +# Start the program running and then wait for a bit, to be sure +# that it can be attached to. + +set test_spawn_id [spawn_wait_for_attach $binfile] +set testpid [spawn_id_get_pid $test_spawn_id] + +remote_exec target "cp -pf -- $binfile $binfile-copy" +remote_exec target "rm -f -- $binfile" + +set test "start gdb" +set res [gdb_spawn_with_cmdline_opts \ + "-iex \"set height 0\" -iex \"set width 0\" /DoEsNoTeXySt $testpid"] +if { $res != 0} { + fail "$test (spawn)" + kill_wait_spawned_process $test_spawn_id + return -1 +} +gdb_test_multiple "" $test { + -re "\r\nAttaching to .*\r\n$gdb_prompt $" { + pass $test + } +} + +kill_wait_spawned_process $test_spawn_id