From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Fedora GDB patches <invalid@email.com>

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  <jan.kratochvil@redhat.com>

	* 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  <jan.kratochvil@redhat.com>

	* 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

@@ -1115,7 +1115,10 @@ captured_main_1 (struct captured_main_args *context)

       if (isdigit (pid_or_core_arg[0]))

 	{

 	  if (catch_command_errors (attach_command, pid_or_core_arg,

-				    !batch_flag) == 0)

+				    !batch_flag) == 0

+	      /* attach_command could succeed partially and core_file_command

+		 would try to kill it.  */

+	      && !have_inferiors ())

 	    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 <http://www.gnu.org/licenses/>.  */

+

+#include <unistd.h>

+

+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 <http://www.gnu.org/licenses/>.

+

+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