From c6479f8b2ab32c8a1659054104f2d0176a466cb3 Mon Sep 17 00:00:00 2001 From: Lancelot SIX Date: Fri, 18 Feb 2022 10:05:51 -0500 Subject: [PATCH] Process exit status is leader exit status testcase 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 Change-Id: I30cba2ff4576fb01b5169cc72667f3268d919557 --- ...rocess-exit-status-is-leader-exit-status.c | 64 +++++++++++++++++++ ...cess-exit-status-is-leader-exit-status.exp | 46 +++++++++++++ 2 files changed, 110 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 . */ + +#include +#include +#include + +#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..655e3134c08 --- /dev/null +++ b/gdb/testsuite/gdb.threads/process-exit-status-is-leader-exit-status.exp @@ -0,0 +1,46 @@ +# 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 . + +# 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 that 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\\\]" + } +} -- 2.30.2