Can't interrupt process without controlling terminal on Solaris (PR gdb/8527)

If gdb attaches to a process that either has no controlling terminal,
or the controlling terminal differs from the one gdb is running under,
break/^C doesn't interrupt the debugged process on Solaris.

Fixed as follows, analogous to what all all other targets do.  Patch from
the PR, recently re-submitted by Brian Vandenberg.

Tested on amd64-pc-solaris2.11, sparcv9-sun-solaris2.11, and
x86_64-pc-linux-gnu.

2019-02-28  Brian Vandenberg  <phantall@gmail.com>
	    Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	gdb:
	PR gdb/8527
	* procfs.c (proc_wait_for_stop): Wrap write of PCWSTOP in
	set_sigint_trap, clear_sigint_trap.

	gdb/testsuite:
	PR gdb/8527
	* gdb.base/interrupt-daemon-attach.c,
	gdb.base/interrupt-daemon-attach.exp: New test.

gdb/ChangeLog

@@ -1,3 +1,10 @@
+2019-02-28  Brian Vandenberg  <phantall@gmail.com>
+	    Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	PR gdb/8527
+	* procfs.c (proc_wait_for_stop): Wrap write of PCWSTOP in
+	set_sigint_trap, clear_sigint_trap.
+
 2019-02-27  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
 
 	* target.c (target_detach): Clear the regcache and the

gdb/procfs.c

@@ -909,7 +909,12 @@ proc_wait_for_stop (procinfo *pi)
 
   procfs_ctl_t cmd = PCWSTOP;
 
+  set_sigint_trap ();
+
   win = (write (pi->ctl_fd, (char *) &cmd, sizeof (cmd)) == sizeof (cmd));
+
+  clear_sigint_trap ();
+
   /* We been runnin' and we stopped -- need to update status.  */
   pi->status_valid = 0;
 

gdb/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2019-02-28  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	PR gdb/8527
+	* gdb.base/interrupt-daemon-attach.c,
+	gdb.base/interrupt-daemon-attach.exp: New test.
+
 2019-02-27  Pedro Alves  <palves@redhat.com>
 
 	* gdb.base/page.exp: Add tests for "set width/height -1".

gdb/testsuite/gdb.base/interrupt-daemon-attach.c

@@ -0,0 +1,61 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2017-2019 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 <stdlib.h>
+#include <unistd.h>
+
+/* GDB reads this to figure out the child's PID.  */
+pid_t child_pid;
+
+void
+marker (void)
+{
+}
+
+int
+main ()
+{
+  /* Don't let the test case run forever.  */
+  alarm (60);
+
+  child_pid = fork ();
+
+  switch (child_pid)
+    {
+    case -1:
+      return 1;
+
+    case 0:
+      break;
+
+    default:
+      while (1)
+	{
+	  marker ();
+	  usleep (1000);
+	}
+    }
+
+  /* Detach from controlling terminal.  */
+  if (setsid () == (pid_t) -1)
+    return 1;
+
+  for (;;)
+    ;
+
+  return 0;
+}

gdb/testsuite/gdb.base/interrupt-daemon-attach.exp

@@ -0,0 +1,91 @@
+# Copyright 2019 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 [target_info exists gdb,nosignals] {
+    verbose "Skipping interrupt-daemon-attach.exp because of nosignals."
+    continue
+}
+
+# This test requires sending ^C to interrupt the running target.
+if [target_info exists gdb,nointerrupts] {
+    verbose "Skipping interrupt-daemon-attach.exp because of nointerrupts."
+    return
+}
+
+if { ![can_spawn_for_attach] } {
+    return 0
+}
+
+standard_testfile
+
+if { [build_executable ${testfile}.exp ${testfile} $srcfile {debug}] == -1 } {
+    return -1
+}
+
+proc do_test {} {
+    global binfile
+    global decimal
+
+    set test_spawn_id [spawn_wait_for_attach $binfile]
+    set parent_pid [spawn_id_get_pid $test_spawn_id]
+
+    # Attach to the parent, run it to a known point, extract the
+    # child's PID, and detach.
+    with_test_prefix "parent" {
+	clean_restart ${binfile}
+
+	gdb_test "attach $parent_pid" \
+	    "Attaching to program.*, process $parent_pid.*" \
+	    "attach"
+
+	gdb_breakpoint "marker"
+	gdb_continue_to_breakpoint "marker"
+
+	set child_pid [get_integer_valueof "child_pid" -1]
+	if {$child_pid == -1} {
+	    return
+	}
+
+	gdb_test "detach" \
+	    "Detaching from program: .*process $parent_pid\r\n\\\[Inferior $decimal \\(.*\\) detached\\\]"
+
+	remote_exec host "kill -9 $parent_pid"
+    }
+
+    # Start over, and attach to the child this time.
+    with_test_prefix "child" {
+	global gdb_prompt
+
+	clean_restart $binfile
+
+	gdb_test "attach $child_pid" \
+	    "Attaching to program.*, process $child_pid.*" \
+	    "attach"
+
+	gdb_test_multiple "continue" "continue" {
+	    -re "Continuing" {
+		pass "continue"
+	    }
+	}
+
+	after 500 {send_gdb "\003"}
+	gdb_test "" "(Program|Thread .*) received signal SIGINT.*" \
+	    "stop with control-c"
+
+	remote_exec host "kill -9 $child_pid"
+    }
+}
+
+do_test