[v6,5/5] gdb/infrun: handle already-exited threads when attempting to stop

Message ID 034167b6db428b2f6f213eeea4ad042755b37f83.1587415578.git.tankut.baris.aktemur@intel.com
State New
Headers show
Series
  • Untitled series #24687
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Commit Message

Simon Marchi via Gdb-patches April 20, 2020, 8:48 p.m.
In stop_all_threads, GDB sends signals to other threads in an attempt
to stop them.  While in a typical scenario the expected wait status is
TARGET_WAITKIND_STOPPED, it is possible that the thread GDB attempted
to stop has already terminated.  If so, a waitstatus other than
TARGET_WAITKIND_STOPPED would be received.  Handle this case
appropriately.

If a wait status that denotes thread termination is ignored, GDB goes
into an infinite loop in stop_all_threads.
E.g.:

  $ gdb ./a.out
  (gdb) start
  ...
  (gdb) add-inferior -exec ./a.out
  ...
  (gdb) inferior 2
  ...
  (gdb) start
  ...
  (gdb) set schedule-multiple on
  (gdb) set debug infrun 2
  (gdb) continue
  Continuing.
  infrun: clear_proceed_status_thread (process 10449)
  infrun: clear_proceed_status_thread (process 10453)
  infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
  infrun: proceed: resuming process 10449
  infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 10449] at 0x55555555514e
  infrun: infrun_async(1)
  infrun: prepare_to_wait
  infrun: proceed: resuming process 10453
  infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 10453] at 0x55555555514e
  infrun: prepare_to_wait
  infrun: Found 2 inferiors, starting at #0
  infrun: target_wait (-1.0.0, status) =
  infrun:   10449.10449.0 [process 10449],
  infrun:   status->kind = exited, status = 0
  infrun: handle_inferior_event status->kind = exited, status = 0
  [Inferior 1 (process 10449) exited normally]
  infrun: stop_waiting
  infrun: stop_all_threads
  infrun: stop_all_threads, pass=0, iterations=0
  infrun:   process 10453 executing, need stop
  infrun: target_wait (-1.0.0, status) =
  infrun:   10453.10453.0 [process 10453],
  infrun:   status->kind = exited, status = 0
  infrun: stop_all_threads status->kind = exited, status = 0 process 10453
  infrun:   process 10453 executing, already stopping
  infrun: target_wait (-1.0.0, status) =
  infrun:   -1.0.0 [process -1],
  infrun:   status->kind = no-resumed
  infrun: infrun_async(0)
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  infrun: stop_all_threads status->kind = no-resumed process -1
  infrun:   process 10453 executing, already stopping
  ...

And this polling goes on forever.  This patch prevents the infinite
looping behavior.  For the same scenario above, we obtain the
following behavior:

  ...
  (gdb) continue
  Continuing.
  infrun: clear_proceed_status_thread (process 31229)
  infrun: clear_proceed_status_thread (process 31233)
  infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
  infrun: proceed: resuming process 31229
  infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 31229] at 0x55555555514e
  infrun: infrun_async(1)
  infrun: prepare_to_wait
  infrun: proceed: resuming process 31233
  infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 31233] at 0x55555555514e
  infrun: prepare_to_wait
  infrun: Found 2 inferiors, starting at #0
  infrun: target_wait (-1.0.0, status) =
  infrun:   31229.31229.0 [process 31229],
  infrun:   status->kind = exited, status = 0
  infrun: handle_inferior_event status->kind = exited, status = 0
  [Inferior 1 (process 31229) exited normally]
  infrun: stop_waiting
  infrun: stop_all_threads
  infrun: stop_all_threads, pass=0, iterations=0
  infrun:   process 31233 executing, need stop
  infrun: target_wait (-1.0.0, status) =
  infrun:   31233.31233.0 [process 31233],
  infrun:   status->kind = exited, status = 0
  infrun: stop_all_threads status->kind = exited, status = 0 process 31233
  infrun: saving status status->kind = exited, status = 0 for 31233.31233.0
  infrun:   process 31233 not executing
  infrun: stop_all_threads, pass=1, iterations=1
  infrun:   process 31233 not executing
  infrun: stop_all_threads done
  (gdb)

The exit event from Inferior 1 is received and shown to the user.
The exit event from Inferior 2 is not displayed, but kept pending.

  (gdb) info inferiors
    Num  Description       Connection           Executable
  * 1    <null>                                 a.out
    2    process 31233     1 (native)           a.out
  (gdb) inferior 2
  [Switching to inferior 2 [process 31233] (a.out)]
  [Switching to thread 2.1 (process 31233)]
  Couldn't get registers: No such process.
  (gdb) continue
  Continuing.
  infrun: clear_proceed_status_thread (process 31233)
  infrun: clear_proceed_status_thread: thread process 31233 has pending wait status status->kind = exited, status = 0 (currently_stepping=0).
  infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
  infrun: proceed: resuming process 31233
  infrun: resume: thread process 31233 has pending wait status status->kind = exited, status = 0 (currently_stepping=0).
  infrun: prepare_to_wait
  infrun: Using pending wait status status->kind = exited, status = 0 for process 31233.
  infrun: target_wait (-1.0.0, status) =
  infrun:   31233.31233.0 [process 31233],
  infrun:   status->kind = exited, status = 0
  infrun: handle_inferior_event status->kind = exited, status = 0
  [Inferior 2 (process 31233) exited normally]
  infrun: stop_waiting
  (gdb) info inferiors
    Num  Description       Connection           Executable
    1    <null>                                 a.out
  * 2    <null>                                 a.out
  (gdb)

Regression-tested on X86_64 Linux.

gdb/ChangeLog:
2020-02-05  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
	    Tom de Vries  <tdevries@suse.de>

	PR threads/25478
	* infrun.c (stop_all_threads): Do NOT ignore
	TARGET_WAITKIND_NO_RESUMED, TARGET_WAITKIND_THREAD_EXITED,
	TARGET_WAITKIND_EXITED, TARGET_WAITKIND_SIGNALLED wait statuses
	received from threads we attempt to stop.

gdb/testsuite/ChangeLog:
2019-11-04  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* gdb.multi/multi-exit.c: New file.
	* gdb.multi/multi-exit.exp: New file.
	* gdb.multi/multi-kill.c: New file.
	* gdb.multi/multi-kill.exp: New file.

Change-Id: I7cec98f40283773b79255d998511da434e9cd408
---
 gdb/infrun.c                           |  62 ++++++++++++--
 gdb/testsuite/gdb.multi/multi-exit.c   |  22 +++++
 gdb/testsuite/gdb.multi/multi-exit.exp | 110 ++++++++++++++++++++++++
 gdb/testsuite/gdb.multi/multi-kill.c   |  42 ++++++++++
 gdb/testsuite/gdb.multi/multi-kill.exp | 112 +++++++++++++++++++++++++
 5 files changed, 340 insertions(+), 8 deletions(-)
 create mode 100644 gdb/testsuite/gdb.multi/multi-exit.c
 create mode 100644 gdb/testsuite/gdb.multi/multi-exit.exp
 create mode 100644 gdb/testsuite/gdb.multi/multi-kill.c
 create mode 100644 gdb/testsuite/gdb.multi/multi-kill.exp

-- 
2.17.1

Comments

Simon Marchi via Gdb-patches April 21, 2020, 7:35 p.m. | #1
Some nits in the testcase below, but otherwise,
this is OK, pending resolution of the preparatory
patch under discussion.

On 4/20/20 9:48 PM, Tankut Baris Aktemur wrote:

> +# We are testing GDB's ability to stop all threads.

> +# Hence, go with the all-stop-on-top-of-non-stop mode.

> +# This is an overridden function.

> +

> +proc default_gdb_start_post_cmd { } {

> +    gdb_test_no_output "maint set target-non-stop on"

> +}


Recall to update this.

> +

> +# We want GDB to complete the command and return the prompt

> +# instead of going into an infinite loop.

> +gdb_test_multiple "continue" "first continue" {

> +    -re "Inferior ($decimal) \[^\n\r\]+ exited normally.*$gdb_prompt $" {

> +	set exited_inferior $expect_out(1,string)

> +	pass $gdb_test_name

> +    }

> +}

> +

> +if {![info exists exited_inferior]} {


We don't usually use this pattern for a similar
reason to the one I pointed before -- variables
can leak between testcases.  So what we normally
do is clear the variable before gdb_test_multiple,
like:

 set exited_inferior ""

 # We want GDB to complete the command and return the prompt
 # instead of going into an infinite loop.
 gdb_test_multiple "continue" "first continue" {
     -re "Inferior ($decimal) \[^\n\r\]+ exited normally.*$gdb_prompt $" {
 	set exited_inferior $expect_out(1,string)
 	pass $gdb_test_name
     }
 }

 if {$exited_inferior != ""} {

> +# We are testing GDB's ability to stop all threads.

> +# Hence, go with the all-stop-on-top-of-non-stop mode.

> +# This is an overridden function.

> +

> +proc default_gdb_start_post_cmd { } {

> +    gdb_test_no_output "maint set target-non-stop on"

> +}


Ditto.

> +

> +if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug}]} {

> +    return -1

> +}

> +

> +with_test_prefix "inf 1" {

> +    gdb_load $binfile

> +

> +    gdb_breakpoint "initialized" {temporary}

> +    gdb_run_cmd

> +    gdb_test "" ".*reakpoint ., initialized .*${srcfile}.*" "run"

> +

> +    set testpid1 [get_integer_valueof "pid" -1]

> +    if { $testpid1 == -1 } {

> +	return -1

> +    }

> +}


...

> +with_test_prefix "inf 2" {

> +    gdb_load $binfile

> +

> +    gdb_breakpoint "initialized" {temporary}

> +    gdb_run_cmd

> +    gdb_test "" ".*reakpoint ., initialized .*${srcfile}.*" "run"

> +

> +    set testpid2 [get_integer_valueof "pid" -1]

> +    if { $testpid2 == -1 } {

> +	return -1

> +    }

> +}


Seems like this duplicated code to start the inferior
and get its pid could be moved to a shared procedure.

proc initialize_inferior {prefix} {
  with_test_prefix $prefix {
    gdb_load $binfile

    gdb_breakpoint "initialized" {temporary}
    gdb_run_cmd
    gdb_test "" ".*reakpoint ., initialized .*${srcfile}.*" "run"

   return [get_integer_valueof "pid" -1]
  }
}

set testpid1 [initialize_inferior "inf 1"]
if { $testpid1 == -1 } {
   return -1
}

# ... add inf 2, switch to it, then:

set testpid2 [initialize_inferior "inf 2"]
if { $testpid2 == -1 } {
   return -1
}

Thanks,
Pedro Alves

Patch

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 167d50ff3ab..86665d1f35d 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -4761,8 +4761,6 @@  stop_all_threads (void)
   if (debug_infrun)
     fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
 
-  scoped_restore_current_thread restore_thread;
-
   target_thread_events (1);
   SCOPE_EXIT { target_thread_events (0); };
 
@@ -4781,6 +4779,7 @@  stop_all_threads (void)
 	{
 	  int need_wait = 0;
 
+	  scoped_restore_current_thread restore_thread;
 	  update_thread_list ();
 
 	  /* Go through all threads looking for threads that we need
@@ -4856,13 +4855,60 @@  stop_all_threads (void)
 				  target_pid_to_str (event.ptid).c_str ());
 	    }
 
-	  if (event.ws.kind == TARGET_WAITKIND_NO_RESUMED
-	      || event.ws.kind == TARGET_WAITKIND_THREAD_EXITED
-	      || event.ws.kind == TARGET_WAITKIND_EXITED
-	      || event.ws.kind == TARGET_WAITKIND_SIGNALLED)
+	  if (event.ws.kind == TARGET_WAITKIND_NO_RESUMED)
+	    {
+	      /* All resumed threads exited.  */
+	    }
+	  else if (event.ws.kind == TARGET_WAITKIND_THREAD_EXITED
+		   || event.ws.kind == TARGET_WAITKIND_EXITED
+		   || event.ws.kind == TARGET_WAITKIND_SIGNALLED)
 	    {
-	      /* All resumed threads exited
-		 or one thread/process exited/signalled.  */
+	      /* One thread/process exited/signalled.  */
+
+	      thread_info *t = nullptr;
+
+	      /* The target may have reported just a pid.  If so, try
+		 the first non-exited thread.  */
+	      if (event.ptid.is_pid ())
+		{
+		  int pid  = event.ptid.pid ();
+		  inferior *inf = find_inferior_pid (event.target, pid);
+		  for (thread_info *tp : inf->non_exited_threads ())
+		    {
+		      t = tp;
+		      break;
+		    }
+
+		  /* FIXME: If there is no available thread, the event
+		     would have to be appended to a per-inferior event
+		     list, which, unfortunately, does not exist yet.  We
+		     assert here instead of going into an infinite loop.  */
+		  gdb_assert (t != nullptr);
+
+		  if (debug_infrun)
+		    fprintf_unfiltered (gdb_stdlog,
+					"infrun: stop_all_threads, using %s\n",
+					target_pid_to_str (t->ptid).c_str ());
+		}
+	      else
+		{
+		  t = find_thread_ptid (event.target, event.ptid);
+		  /* Check if this is the first time we see this thread.
+		     Don't bother adding if it individually exited.  */
+		  if (t == nullptr
+		      && event.ws.kind != TARGET_WAITKIND_THREAD_EXITED)
+		    t = add_thread (event.target, event.ptid);
+		}
+
+	      if (t != nullptr)
+		{
+		  /* Set the threads as non-executing to avoid
+		     another stop attempt on them.  */
+		  mark_non_executing_threads (event.target, event.ptid,
+					      event.ws);
+		  save_waitstatus (t, &event.ws);
+		  t->stop_requested = false;
+		}
 	    }
 	  else
 	    {
diff --git a/gdb/testsuite/gdb.multi/multi-exit.c b/gdb/testsuite/gdb.multi/multi-exit.c
new file mode 100644
index 00000000000..f4825c8a7c1
--- /dev/null
+++ b/gdb/testsuite/gdb.multi/multi-exit.c
@@ -0,0 +1,22 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2020 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/>.  */
+
+int
+main ()
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.multi/multi-exit.exp b/gdb/testsuite/gdb.multi/multi-exit.exp
new file mode 100644
index 00000000000..b5ef0b250dd
--- /dev/null
+++ b/gdb/testsuite/gdb.multi/multi-exit.exp
@@ -0,0 +1,110 @@ 
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2020 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 receiving TARGET_WAITKIND_EXITED events from multiple
+# inferiors.  In all stop-mode, upon receiving the exit event from one
+# of the inferiors, GDB will try to stop the other inferior, too.  So,
+# a stop request will be sent.  Receiving a TARGET_WAITKIND_EXITED
+# status kind as a response to that stop request instead of a
+# TARGET_WAITKIND_STOPPED should be handled by GDB without problems.
+
+standard_testfile
+
+if {[use_gdb_stub]} {
+    return 0
+}
+
+# We are testing GDB's ability to stop all threads.
+# Hence, go with the all-stop-on-top-of-non-stop mode.
+# This is an overridden function.
+
+proc default_gdb_start_post_cmd { } {
+    gdb_test_no_output "maint set target-non-stop on"
+}
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug}]} {
+    return -1
+}
+
+with_test_prefix "inf 1" {
+    gdb_load $binfile
+
+    if {[gdb_start_cmd] < 0} {
+	fail "could not start"
+	return -1
+    }
+    gdb_test "" ".*reakpoint ., main .*${srcfile}.*" "start"
+}
+
+# Start another inferior.
+gdb_test "add-inferior" "Added inferior 2.*" \
+    "add empty inferior 2"
+gdb_test "inferior 2" "Switching to inferior 2.*" \
+    "switch to inferior 2"
+
+with_test_prefix "inf 2" {
+    gdb_load $binfile
+
+    if {[gdb_start_cmd] < 0} {
+	fail "could not start"
+	return -1
+    }
+    gdb_test "" ".*reakpoint ., main .*${srcfile}.*" "start"
+}
+
+# We want to continue both processes.
+gdb_test_no_output "set schedule-multiple on"
+
+# We want GDB to complete the command and return the prompt
+# instead of going into an infinite loop.
+gdb_test_multiple "continue" "first continue" {
+    -re "Inferior ($decimal) \[^\n\r\]+ exited normally.*$gdb_prompt $" {
+	set exited_inferior $expect_out(1,string)
+	pass $gdb_test_name
+    }
+}
+
+if {![info exists exited_inferior]} {
+    fail "first continue"
+    return -1
+}
+
+if {$exited_inferior == 1} {
+    set other_inferior 2
+} else {
+    set other_inferior 1
+}
+
+# Switch to the other inferior and check it, too, continues to the end.
+gdb_test "inferior $other_inferior" \
+    ".*Switching to inferior $other_inferior.*" \
+    "switch to the other inferior"
+
+gdb_continue_to_end
+
+# Finally, check if we can re-run both inferiors.
+delete_breakpoints
+
+gdb_test "run" "$inferior_exited_re normally\]" \
+    "re-run the other inferior"
+
+gdb_test "inferior $exited_inferior" \
+    ".*Switching to inferior $exited_inferior.*" \
+    "switch to the first exited inferior"
+
+gdb_test "run" "$inferior_exited_re normally\]" \
+    "re-run the first exited inferior"
diff --git a/gdb/testsuite/gdb.multi/multi-kill.c b/gdb/testsuite/gdb.multi/multi-kill.c
new file mode 100644
index 00000000000..66642bbb0e6
--- /dev/null
+++ b/gdb/testsuite/gdb.multi/multi-kill.c
@@ -0,0 +1,42 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2020 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 <sys/types.h>
+#include <unistd.h>
+
+static pid_t pid;
+
+static void
+initialized ()
+{
+}
+
+int
+main ()
+{
+  pid = getpid ();
+  initialized ();
+
+  /* Don't run forever in case GDB crashes and DejaGNU fails to kill
+     this program.  */
+  alarm (10);
+
+  while (1)
+    ;
+
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.multi/multi-kill.exp b/gdb/testsuite/gdb.multi/multi-kill.exp
new file mode 100644
index 00000000000..55cd877069e
--- /dev/null
+++ b/gdb/testsuite/gdb.multi/multi-kill.exp
@@ -0,0 +1,112 @@ 
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2020 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 receiving TARGET_WAITKIND_SIGNALLED events from multiple
+# inferiors.  In all stop-mode, upon receiving the exit event from one
+# of the inferiors, GDB will try to stop the other inferior, too.  So,
+# a stop request will be sent.  Receiving a TARGET_WAITKIND_SIGNALLED
+# status kind as a response to that stop request instead of a
+# TARGET_WAITKIND_STOPPED should be handled by GDB without problems.
+
+standard_testfile
+
+if {[use_gdb_stub]} {
+    return 0
+}
+
+# We are testing GDB's ability to stop all threads.
+# Hence, go with the all-stop-on-top-of-non-stop mode.
+# This is an overridden function.
+
+proc default_gdb_start_post_cmd { } {
+    gdb_test_no_output "maint set target-non-stop on"
+}
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug}]} {
+    return -1
+}
+
+with_test_prefix "inf 1" {
+    gdb_load $binfile
+
+    gdb_breakpoint "initialized" {temporary}
+    gdb_run_cmd
+    gdb_test "" ".*reakpoint ., initialized .*${srcfile}.*" "run"
+
+    set testpid1 [get_integer_valueof "pid" -1]
+    if { $testpid1 == -1 } {
+	return -1
+    }
+}
+
+# Start another inferior.
+gdb_test "add-inferior" "Added inferior 2.*" \
+    "add empty inferior 2"
+gdb_test "inferior 2" "Switching to inferior 2.*" \
+    "switch to inferior 2"
+
+with_test_prefix "inf 2" {
+    gdb_load $binfile
+
+    gdb_breakpoint "initialized" {temporary}
+    gdb_run_cmd
+    gdb_test "" ".*reakpoint ., initialized .*${srcfile}.*" "run"
+
+    set testpid2 [get_integer_valueof "pid" -1]
+    if { $testpid2 == -1 } {
+	return -1
+    }
+}
+
+# We want to continue both processes.
+gdb_test_no_output "set schedule-multiple on"
+
+# Resume, but then kill both from outside.
+gdb_test_multiple "continue" "continue processes" {
+    -re "Continuing.\[\r\n\]+" {
+	# Kill both processes at once.
+	remote_exec target "kill -9 ${testpid1} ${testpid2}"
+	exp_continue
+    }
+    -re "Program terminated with signal.*$gdb_prompt" {
+	pass $gdb_test_name
+    }
+}
+
+# Find the current inferior's id.
+set current_inferior 1
+gdb_test_multiple "info inferiors" "find the current inf id" {
+    -re "\\* 1 .*$gdb_prompt $" {
+	set current_inferior 1
+	set other_inferior 2
+	pass $gdb_test_name
+    }
+    -re "\\* 2 .*$gdb_prompt $" {
+	set current_inferior 2
+	set other_inferior 1
+	pass $gdb_test_name
+    }
+}
+
+# Switch to the other inferior and check it, too, continues to the end.
+gdb_test "inferior $other_inferior" \
+    ".*Switching to inferior $other_inferior.*" \
+    "switch to the other inferior"
+
+gdb_test "continue" \
+    "Program terminated with signal SIGKILL, .*" \
+    "continue the other inferior"