From: Pedro Alves <pedro@palves.net>
To: gdb-patches@sourceware.org
Subject: [PATCH 11/11] Process exit status is leader exit status testcase
Date: Thu, 3 Mar 2022 14:40:20 +0000 [thread overview]
Message-ID: <20220303144020.3601082-12-pedro@palves.net> (raw)
In-Reply-To: <20220303144020.3601082-1-pedro@palves.net>
From: Lancelot SIX <lancelot.six@amd.com>
This adds a multi-threaded testcase that has all threads in the
process exit with a different exit code, and ensures that GDB reports
the thread group leader's exit status as the whole-process exit
status. Before this set of patches, this would randomly report the
exit code of some other thread, and thus fail.
Tested on Linux-x86_64, native and gdbserver.
Co-Authored-By: Pedro Alves <pedro@palves.net>
Change-Id: I30cba2ff4576fb01b5169cc72667f3268d919557
---
...rocess-exit-status-is-leader-exit-status.c | 64 +++++++++++++++++++
...cess-exit-status-is-leader-exit-status.exp | 45 +++++++++++++
2 files changed, 109 insertions(+)
create mode 100644 gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.c
create mode 100644 gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.exp
diff --git a/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.c b/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.c
new file mode 100644
index 00000000000..c27c266ef28
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.c
@@ -0,0 +1,64 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2022 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 <pthread.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+#define NUM_THREADS 32
+
+pthread_barrier_t barrier;
+
+static void
+do_exit (int exitcode)
+{
+ /* Synchronize all threads up to here so that they all exit at
+ roughly the same time. */
+ pthread_barrier_wait (&barrier);
+
+ /* All threads exit with SYS_exit, even the main thread, to avoid
+ exiting with a group-exit syscall, as that syscall changes the
+ exit status of all still-alive threads, thus potentially masking
+ a bug. */
+ syscall (SYS_exit, exitcode);
+}
+
+static void *
+start (void *arg)
+{
+ int thread_return_value = *(int *) arg;
+
+ do_exit (thread_return_value);
+}
+
+int
+main(void)
+{
+ pthread_t threads[NUM_THREADS];
+ int thread_return_val[NUM_THREADS];
+ int i;
+
+ pthread_barrier_init (&barrier, NULL, NUM_THREADS + 1);
+
+ for (i = 0; i < NUM_THREADS; ++i)
+ {
+ thread_return_val[i] = i + 2;
+ pthread_create (&threads[i], NULL, start, &thread_return_val[i]);
+ }
+
+ do_exit (1);
+}
diff --git a/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.exp b/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.exp
new file mode 100644
index 00000000000..655e4bc209b
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.exp
@@ -0,0 +1,45 @@
+# Copyright (C) 2022 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/>.
+
+# GDB must always report the process's exit status based on the exit
+# status of the thread group leader thread. Test that when multiple
+# threads exit simultaneously, GDB doesn't confuse the non-leader
+# threads' exit status for the process's exit status. GDB used to
+# have a race condition to led to randomly handling this incorrectly.
+#
+# Since the improper behavior is racy in nature, this test is not
+# expected to be able to reproduce the error reliably. Multiple
+# executions (or increasing the number of iterations) might be
+# required to reproduce the error with a misbehaving GDB.
+
+if { ![istarget "*-*-linux*"] } {
+ return 0
+}
+
+standard_testfile
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug pthreads}] == -1} {
+ return -1
+}
+
+for {set iteration 0} {$iteration < 10} {incr iteration} {
+ with_test_prefix "iteration=$iteration" {
+ if {![runto_main]} {
+ return
+ }
+
+ gdb_test "continue" "\\\[Inferior 1 \\(.*\\) exited with code 01\\\]"
+ }
+}
--
2.26.2
next prev parent reply other threads:[~2022-03-03 14:40 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-03 14:40 [PATCH 00/11] Linux: Fix issues around thread group leader exits Pedro Alves
2022-03-03 14:40 ` [PATCH 01/11] Fix gdbserver/linux target_waitstatus logging assert Pedro Alves
2022-03-03 14:40 ` [PATCH 02/11] Fix gdb.threads/clone-new-thread-event.exp race Pedro Alves
2022-03-03 14:40 ` [PATCH 03/11] Fix gdb.threads/current-lwp-dead.exp race Pedro Alves
2022-03-03 14:40 ` [PATCH 04/11] gdb: Reorganize linux_nat_filter_event Pedro Alves
2022-03-03 14:40 ` [PATCH 05/11] gdbserver: Reorganize linux_process_target::filter_event Pedro Alves
2022-03-03 14:40 ` [PATCH 06/11] gdbserver: Reindent check_zombie_leaders Pedro Alves
2022-03-03 14:40 ` [PATCH 07/11] Re-add zombie leader on exit, gdb/linux Pedro Alves
2022-03-07 20:08 ` Simon Marchi
2022-03-07 20:27 ` Pedro Alves
2022-03-07 20:31 ` Simon Marchi
2022-03-09 14:37 ` Pedro Alves
2022-03-03 14:40 ` [PATCH 08/11] Re-add zombie leader on exit, gdbserver/linux Pedro Alves
2022-03-03 14:40 ` [PATCH 09/11] Ensure EXIT is last event, gdb/linux Pedro Alves
2022-03-07 20:24 ` Simon Marchi
2022-03-09 0:21 ` Lancelot SIX
2022-03-09 14:45 ` Pedro Alves
2022-03-09 22:29 ` Lancelot SIX
2022-03-10 11:46 ` Pedro Alves
2022-03-03 14:40 ` [PATCH 10/11] Ensure EXIT is last event, gdbserver/linux Pedro Alves
2022-03-03 14:40 ` Pedro Alves [this message]
2023-06-22 11:28 ` [PATCH 11/11] Process exit status is leader exit status testcase Ilya Leoshkevich
2023-06-22 13:07 ` Tom de Vries
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