1#!/bin/sh
2
3#
4# Copyright (c) 2016 EMC Corp.
5# All rights reserved.
6#
7# Redistribution and use in source and binary forms, with or without
8# modification, are permitted provided that the following conditions
9# are met:
10# 1. Redistributions of source code must retain the above copyright
11#    notice, this list of conditions and the following disclaimer.
12# 2. Redistributions in binary form must reproduce the above copyright
13#    notice, this list of conditions and the following disclaimer in the
14#    documentation and/or other materials provided with the distribution.
15#
16# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26# SUCH DAMAGE.
27#
28
29# It seems to be possible for ptrace(PT_ATTACH) to race with the delivery
30# of a signal to the same process.
31
32# "panic: Assertion TD_IS_SLEEPING(td) failed at subr_sleepqueue.c:958".
33# https://people.freebsd.org/~pho/stress/log/ptrace5.txt
34# https://people.freebsd.org/~pho/stress/log/ptrace5-2.txt
35# Fixed by r303426.
36
37. ../default.cfg
38
39dir=/tmp
40odir=`pwd`
41cd $dir
42sed '1,/^EOF/d' < $odir/$0 > $dir/ptrace5.c
43mycc -o ptrace5 -Wall -Wextra -O0 -g ptrace5.c -pthread || exit 1
44rm -f ptrace5.c
45cd $odir
46
47/tmp/ptrace5
48s=$?
49
50rm -rf /tmp/ptrace5
51exit $s
52
53EOF
54#include <sys/param.h>
55#include <sys/ptrace.h>
56#include <sys/stat.h>
57#include <sys/wait.h>
58
59#include <err.h>
60#include <errno.h>
61#include <fcntl.h>
62#include <pthread.h>
63#include <signal.h>
64#include <stdio.h>
65#include <stdlib.h>
66#include <time.h>
67#include <unistd.h>
68
69static pid_t pid;
70static pthread_barrier_t barr;
71static int cont;
72
73#define PARALLEL 4
74#define RUNTIME (5 * 60)
75
76static void
77ahandler(int i __unused)
78{
79	system("ps -Hl");
80	fprintf(stderr, "SIGALRM pid %d\n", pid);
81	exit(1);
82}
83
84static void
85handler(int i __unused)
86{
87}
88
89static void *
90t1(void *data __unused)
91{
92	int status;
93
94	while (cont == 1) {
95		if (ptrace(PT_ATTACH, pid, 0, 0) == -1)
96			err(1, "ptrace(%d)", pid);
97
98		if (waitpid(pid, &status, 0) == -1)
99			err(1, "waitpid");
100		else if (!WIFSTOPPED(status))
101			errx(1, "failed to stop child");
102		if (ptrace(PT_DETACH, pid, 0, 0) == -1)
103			err(1, "ptrace");
104		usleep(arc4random() % 200);
105	}
106
107	return (NULL);
108}
109
110static void *
111t2(void *data __unused)
112{
113	while (cont == 1) {
114		if (kill(pid, SIGHUP) == -1)
115			err(1, "kill");
116		usleep(arc4random() % 200);
117	}
118
119	return (NULL);
120}
121
122static void
123test(void)
124{
125	pthread_t tid[2];
126	struct sigaction sa;
127	int r, status;
128
129	r = pthread_barrier_wait(&barr);
130	if (r != 0 && r != PTHREAD_BARRIER_SERIAL_THREAD)
131	    errc(1, r, "pthread_barrier_wait");
132
133	sa.sa_handler = ahandler;
134	sigemptyset(&sa.sa_mask);
135	sa.sa_flags = 0;
136	if (sigaction(SIGALRM, &sa, NULL) == -1)
137		err(1, "sigaction");
138	alarm(2 * RUNTIME);
139	sa.sa_handler = handler;
140	sigemptyset(&sa.sa_mask);
141	sa.sa_flags = 0;
142	if (sigaction(SIGHUP, &sa, NULL) == -1)
143		err(1, "sigaction");
144
145	if ((pid = fork()) == 0) {
146		for(;;)
147			usleep(20);
148
149		_exit(0);
150	}
151
152	cont = 1;
153	if ((r = pthread_create(&tid[0], NULL, t1, NULL)) == -1)
154		errc(1, r, "pthread_create");
155	if ((r = pthread_create(&tid[1], NULL, t2, NULL)) == -1)
156		errc(1, r, "pthread_create");
157
158	sleep(RUNTIME);
159
160	cont = 0;
161	if ((r = pthread_join(tid[0], NULL)) == -1)
162			errc(1, r, "pthread_join");
163	if ((r = pthread_join(tid[1], NULL)) == -1)
164			errc(1, r, "pthread_join");
165	if (kill(pid, SIGKILL) != 0)
166		err(1, "kill(%d)", pid);
167	waitpid(pid, &status, 0);
168
169	exit(0);
170}
171
172int
173main(void)
174{
175	pthread_barrierattr_t attr;
176	int e, i, pids[PARALLEL], r, status;
177
178	if ((r = pthread_barrierattr_init(&attr)) != 0)
179		errc(1, r, "pthread_barrierattr_init");
180	if ((r = pthread_barrierattr_setpshared(&attr,
181	    PTHREAD_PROCESS_SHARED)) != 0)
182		errc(1, r, "pthread_barrierattr_setpshared");
183	if ((r = pthread_barrier_init(&barr, &attr, PARALLEL)) != 0)
184		errc(1, r, "pthread_barrier_init");
185
186	e = 0;
187	for (i = 0; i < PARALLEL; i++) {
188		if ((pids[i] = fork()) == 0)
189			test();
190	}
191	for (i = 0; i < PARALLEL; i++) {
192		waitpid(pids[i], &status, 0);
193		e += status == 0 ? 0 : 1;
194	}
195
196	if ((r = pthread_barrier_destroy(&barr)) > 0)
197		errc(1, r, "pthread_barrier_destroy");
198
199	return (e);
200}
201