GDBserver: Fix ignored Ctrl-C after reconnection
Commit Message
This fixes the issue reported by Dmitry Antipov <dantipov@nvidia.com>
here:
https://sourceware.org/ml/gdb/2017-10/msg00048.html
The problem is that GDBserver stops listening to Ctrl-C/interrupt
requests if you disconnect and reconnect back.
Dmitry wrote:
~~~
Currently gdbserver installs SIGIO handler just once, in
initialize_async_io() called from captured_main(), and this handler is
removed when remote_desc is closed in remote_close(). Next, when a
new instance of remote_desc is fetched from accept() and has '\003'
arrived, input_interrupt() is never called because it is not
registered as SIGIO handler.
~~~
The fix here is not remove the SIGIO handler in the first place, thus
going back to the original before-first-connection state.
(I haven't gone back to try it, but I think this was a regression
caused by commit 8b2073398477 ("[GDBserver] Block and unblock SIGIO"),
which was what made remote_close remove the signal handler.)
New test included.
gdb/gdbserver/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>
* remote-utils.c (remote_close): Block SIGIO signals instead of
uninstalling the SIGIO handler.
gdb/testsuite/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>
* gdb.server/reconnect-ctrl-c.c: New file.
* gdb.server/reconnect-ctrl-c.exp: New file.
---
gdb/gdbserver/remote-utils.c | 5 +-
gdb/testsuite/gdb.server/reconnect-ctrl-c.c | 28 +++++++++++
gdb/testsuite/gdb.server/reconnect-ctrl-c.exp | 72 +++++++++++++++++++++++++++
3 files changed, 101 insertions(+), 4 deletions(-)
create mode 100644 gdb/testsuite/gdb.server/reconnect-ctrl-c.c
create mode 100644 gdb/testsuite/gdb.server/reconnect-ctrl-c.exp
Comments
On 10/19/2017 02:19 PM, Pedro Alves wrote:
> This fixes the issue reported by Dmitry Antipov <dantipov@nvidia.com>
> here:
> https://sourceware.org/ml/gdb/2017-10/msg00048.html
>
> The problem is that GDBserver stops listening to Ctrl-C/interrupt
> requests if you disconnect and reconnect back.
I've pushed this in now.
(PR22435 reminded me about this, though that one looks unrelated.)
Thanks,
Pedro Alves
@@ -403,10 +403,7 @@ remote_close (void)
{
delete_file_handler (remote_desc);
-#ifndef USE_WIN32API
- /* Remove SIGIO handler. */
- signal (SIGIO, SIG_IGN);
-#endif
+ disable_async_io ();
#ifdef USE_WIN32API
closesocket (remote_desc);
new file mode 100644
@@ -0,0 +1,28 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ 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 <http://www.gnu.org/licenses/>. */
+
+#include <unistd.h>
+
+int
+main ()
+{
+ int secs = 30;
+
+ while (secs--)
+ sleep (1);
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,72 @@
+# This testcase is part of GDB, the GNU debugger.
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+# Test that Ctrl-C works after reconnecting.
+
+load_lib gdbserver-support.exp
+
+if { [skip_gdbserver_tests] } {
+ verbose "skipping gdbserver tests"
+ return -1
+}
+
+standard_testfile
+if [prepare_for_testing "failed to prepare" $testfile $srcfile] {
+ return -1
+}
+
+# Make sure we're disconnected, in case we're testing with an
+# extended-remote board, therefore already connected.
+with_test_prefix "preparation" {
+ gdb_test "disconnect" ".*"
+}
+
+# Connect, continue, send Ctrl-C and expect a SIGINT stop.
+
+proc connect_continue_ctrl_c {} {
+ global gdbserver_protocol gdbserver_gdbport
+
+ set res [gdb_target_cmd $gdbserver_protocol $gdbserver_gdbport]
+ if ![gdb_assert {$res == 0} "connect"] {
+ return
+ }
+
+ set test "continue for ctrl-c"
+ gdb_test_multiple "continue" $test {
+ -re "Continuing" {
+ pass $test
+ }
+ }
+
+ after 1000 {send_gdb "\003"}
+ gdb_test "" "Program received signal SIGINT.*" "stop with control-c"
+}
+
+with_test_prefix "first" {
+ # Start GDBserver.
+ set gdbserver_reconnect_p 1
+ set res [gdbserver_start "" $binfile]
+ set gdbserver_protocol [lindex $res 0]
+ set gdbserver_gdbport [lindex $res 1]
+
+ connect_continue_ctrl_c
+}
+
+with_test_prefix "second" {
+ gdb_test "disconnect" "Ending remote debugging."
+ connect_continue_ctrl_c
+}