From FEDORA_PATCHES Mon Sep 17 00:00:00 2001

From: Tom Tromey <tom@tromey.com>

Date: Fri, 5 Oct 2018 14:54:35 -0600

Subject: gdb-rhbz1653410-avoid-crash-when-calling-warning-too-early.patch

;; Fix for 'GDB crashes when running from a deleted directory'

;; (Tom Tromey, RHBZ#1653410)

Avoid crash when calling warning too early

I noticed that if you pass the name of an existing file (not a

directory) as the argument to --data-directory, gdb will crash:

    $ ./gdb -nx  --data-directory  ./gdb

    ../../binutils-gdb/gdb/target.c:590:56: runtime error: member call on null pointer of type 'struct target_ops'

This was later reported as PR gdb/23838.

This happens because warning ends up calling

target_supports_terminal_ours, which calls current_top_target, which

returns nullptr this early.

This fixes the problem by handling this case specially in

target_supports_terminal_ours.  I also changed

target_supports_terminal_ours to return bool.

gdb/ChangeLog

2018-11-08  Tom Tromey  <tom@tromey.com>

	PR gdb/23555:

	PR gdb/23838:

	* target.h (target_supports_terminal_ours): Return bool.

	* target.c (target_supports_terminal_ours): Handle case where

	current_top_target returns nullptr.  Return bool.

gdb/testsuite/ChangeLog

2018-11-08  Tom Tromey  <tom@tromey.com>

	PR gdb/23555:

	PR gdb/23838:

	* gdb.base/warning.exp: New file.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog

--- a/gdb/ChangeLog

+++ b/gdb/ChangeLog

@@ -1,3 +1,11 @@

+2018-11-08  Tom Tromey  <tom@tromey.com>

+

+	PR gdb/23555:

+	PR gdb/23838:

+	* target.h (target_supports_terminal_ours): Return bool.

+	* target.c (target_supports_terminal_ours): Handle case where

+	current_top_target returns nullptr.  Return bool.

+

 2018-08-16  Gary Benson <gbenson@redhat.com>

 	PR gdb/13000:

diff --git a/gdb/target.c b/gdb/target.c

--- a/gdb/target.c

+++ b/gdb/target.c

@@ -584,10 +584,16 @@ target_terminal::info (const char *arg, int from_tty)

 /* See target.h.  */

-int

+bool

 target_supports_terminal_ours (void)

 {

-  return current_top_target ()->supports_terminal_ours ();

+  /* This can be called before there is any target, so we must check

+     for nullptr here.  */

+  target_ops *top = current_top_target ();

+

+  if (top == nullptr)

+    return false;

+  return top->supports_terminal_ours ();

 }

 static void

diff --git a/gdb/target.h b/gdb/target.h

--- a/gdb/target.h

+++ b/gdb/target.h

@@ -1576,7 +1576,7 @@ extern int target_remove_breakpoint (struct gdbarch *gdbarch,

 /* Return true if the target stack has a non-default

   "terminal_ours" method.  */

-extern int target_supports_terminal_ours (void);

+extern bool target_supports_terminal_ours (void);

 /* Kill the inferior process.   Make it go away.  */

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog

--- a/gdb/testsuite/ChangeLog

+++ b/gdb/testsuite/ChangeLog

@@ -1,3 +1,9 @@

+2018-11-08  Tom Tromey  <tom@tromey.com>

+

+	PR gdb/23555:

+	PR gdb/23838:

+	* gdb.base/warning.exp: New file.

+

 2018-09-04  Gary Benson <gbenson@redhat.com>

 	* gdb.base/batch-exit-status.exp: Use gdb_test_multiple and expect

diff --git a/gdb/testsuite/gdb.base/warning.exp b/gdb/testsuite/gdb.base/warning.exp

new file mode 100644

--- /dev/null

+++ b/gdb/testsuite/gdb.base/warning.exp

@@ -0,0 +1,36 @@

+# Copyright 2018 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/>.

+

+# Test that an early warning does not cause a crash.

+

+if {[is_remote host]} {

+    unsupported "warning.exp can only run on local host"

+    return

+}

+

+set tname [standard_temp_file warning]

+set fd [open $tname w]

+puts $fd "anything"

+close $fd

+

+set save $INTERNAL_GDBFLAGS

+set INTERNAL_GDBFLAGS "-nw -nx -data-directory $tname"

+

+gdb_start

+

+# Make sure gdb started up.

+gdb_test "echo 23\\n" "23"

+

+set INTERNAL_GDBFLAGS $save