1/*
2 * Check decoding of threads when a non-leader thread invokes execve.
3 *
4 * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
5 * Copyright (c) 2016-2017 The strace developers.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "tests.h"
32#include <asm/unistd.h>
33#include <errno.h>
34#include <pthread.h>
35#include <signal.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <time.h>
39#include <unistd.h>
40
41static pid_t leader;
42static pid_t tid;
43
44static void
45handler(int signo)
46{
47}
48
49static unsigned int sigsetsize;
50static long
51k_sigsuspend(const sigset_t *const set)
52{
53	return syscall(__NR_rt_sigsuspend, set, sigsetsize);
54}
55
56static pid_t
57k_gettid(void)
58{
59	return syscall(__NR_gettid);
60}
61
62static void
63get_sigsetsize(void)
64{
65	static const struct sigaction sa = { .sa_handler = handler };
66	if (sigaction(SIGUSR1, &sa, NULL))
67		perror_msg_and_fail("sigaction");
68
69	sigset_t mask;
70	sigemptyset(&mask);
71	sigaddset(&mask, SIGUSR1);
72	if (sigprocmask(SIG_BLOCK, &mask, NULL))
73		perror_msg_and_fail("sigprocmask");
74
75	raise(SIGUSR1);
76
77	sigemptyset(&mask);
78	for (sigsetsize = sizeof(mask) / sizeof(long);
79	     sigsetsize; sigsetsize >>= 1) {
80		long rc = k_sigsuspend(&mask);
81		if (!rc)
82			error_msg_and_fail("rt_sigsuspend");
83		if (EINTR == errno)
84			break;
85		printf("%-5d rt_sigsuspend(%p, %u) = %s\n",
86		       leader, &mask, sigsetsize, sprintrc(rc));
87	}
88	if (!sigsetsize)
89		perror_msg_and_fail("rt_sigsuspend");
90	printf("%-5d rt_sigsuspend([], %u) = ? ERESTARTNOHAND"
91	       " (To be restarted if no handler)\n", leader, sigsetsize);
92}
93
94enum {
95	ACTION_exit = 0,
96	ACTION_rt_sigsuspend,
97	ACTION_nanosleep,
98	NUMBER_OF_ACTIONS
99};
100
101static const unsigned int NUMBER_OF_ITERATIONS = 1;
102static unsigned int action;
103static int fds[2];
104
105static unsigned int
106arglen(char **args)
107{
108	char **p;
109
110	for (p = args; *p; ++p)
111		;
112
113	return p - args;
114}
115
116static void *
117thread(void *arg)
118{
119	tid = k_gettid();
120
121	static char buf[sizeof(action) * 3];
122	sprintf(buf, "%u", action + 1);
123
124	char **argv = arg;
125	argv[2] = buf;
126
127	if (read(fds[0], fds, sizeof(fds[0])))
128		perror_msg_and_fail("execve");
129
130	struct timespec ts = { .tv_nsec = 100000000 };
131	(void) clock_nanosleep(CLOCK_REALTIME, 0, &ts, NULL);
132
133	ts.tv_nsec = 12345;
134	printf("%-5d nanosleep({tv_sec=0, tv_nsec=%u}, NULL) = 0\n",
135	       tid, (unsigned int) ts.tv_nsec);
136
137	switch (action % NUMBER_OF_ACTIONS) {
138		case ACTION_exit:
139			printf("%-5d execve(\"%s\", [\"%s\", \"%s\", \"%s\"]"
140			       ", %p /* %u vars */ <pid changed to %u ...>\n",
141			       tid, argv[0], argv[0], argv[1], argv[2],
142			       environ, arglen(environ), leader);
143			break;
144		case ACTION_rt_sigsuspend:
145			printf("%-5d execve(\"%s\", [\"%s\", \"%s\", \"%s\"]"
146			       ", %p /* %u vars */ <unfinished ...>\n"
147			       "%-5d <... rt_sigsuspend resumed>) = ?\n",
148			       tid, argv[0], argv[0], argv[1], argv[2],
149			       environ, arglen(environ),
150			       leader);
151			break;
152		case ACTION_nanosleep:
153			printf("%-5d execve(\"%s\", [\"%s\", \"%s\", \"%s\"]"
154			       ", %p /* %u vars */ <unfinished ...>\n"
155			       "%-5d <... nanosleep resumed> <unfinished ...>)"
156			       " = ?\n",
157			       tid, argv[0], argv[0], argv[1], argv[2],
158			       environ, arglen(environ),
159			       leader);
160			break;
161	}
162
163	printf("%-5d +++ superseded by execve in pid %u +++\n"
164	       "%-5d <... execve resumed> ) = 0\n",
165	       leader, tid,
166	       leader);
167
168	(void) nanosleep(&ts, NULL);
169	execve(argv[0], argv, environ);
170	perror_msg_and_fail("execve");
171}
172
173int
174main(int ac, char **av)
175{
176	setvbuf(stdout, NULL, _IONBF, 0);
177	leader = getpid();
178
179	if (ac < 3) {
180		struct timespec ts = { .tv_nsec = 1 };
181		if (clock_nanosleep(CLOCK_REALTIME, 0, &ts, NULL))
182			perror_msg_and_skip("clock_nanosleep CLOCK_REALTIME");
183
184		get_sigsetsize();
185		static char buf[sizeof(sigsetsize) * 3];
186		sprintf(buf, "%u", sigsetsize);
187
188		char *argv[] = { av[0], buf, (char *) "0", NULL };
189		printf("%-5d execve(\"%s\", [\"%s\", \"%s\", \"%s\"]"
190		       ", %p /* %u vars */) = 0\n",
191		       leader, argv[0], argv[0], argv[1], argv[2],
192		       environ, arglen(environ));
193		execve(argv[0], argv, environ);
194		perror_msg_and_fail("execve");
195	}
196
197	sigsetsize = atoi(av[1]);
198	action = atoi(av[2]);
199
200	if (action >= NUMBER_OF_ACTIONS * NUMBER_OF_ITERATIONS) {
201		printf("%-5d +++ exited with 0 +++\n", leader);
202		return 0;
203	}
204
205	if (pipe(fds))
206		perror_msg_and_fail("pipe");
207
208	pthread_t t;
209	errno = pthread_create(&t, NULL, thread, av);
210	if (errno)
211		perror_msg_and_fail("pthread_create");
212
213	struct timespec ts = { .tv_sec = 123 };
214	sigset_t mask;
215	sigemptyset(&mask);
216
217	static char leader_str[sizeof(leader) * 3];
218	int leader_str_len =
219		snprintf(leader_str, sizeof(leader_str), "%-5d", leader);
220
221	switch (action % NUMBER_OF_ACTIONS) {
222		case ACTION_exit:
223			printf("%s exit(42)%*s= ?\n", leader_str,
224			       (int) sizeof(leader_str) - leader_str_len, " ");
225			close(fds[1]);
226			(void) syscall(__NR_exit, 42);
227			break;
228		case ACTION_rt_sigsuspend:
229			printf("%s rt_sigsuspend([], %u <unfinished ...>\n",
230			       leader_str, sigsetsize);
231			close(fds[1]);
232			(void) k_sigsuspend(&mask);
233			break;
234		case ACTION_nanosleep:
235			printf("%s nanosleep({tv_sec=%u, tv_nsec=0}"
236			       ",  <unfinished ...>\n",
237			       leader_str, (unsigned int) ts.tv_sec);
238			close(fds[1]);
239			(void) nanosleep(&ts, 0);
240			break;
241	}
242
243	return 1;
244}
245