xref: /freebsd/tests/sys/kern/pdeathsig.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * Copyright (c) 2018 Thomas Munro
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <assert.h>
31 #include <atf-c.h>
32 #include <errno.h>
33 #include <signal.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <time.h>
37 #include <unistd.h>
38 #include <sys/procctl.h>
39 #include <sys/ptrace.h>
40 #include <sys/signal.h>
41 #include <sys/types.h>
42 
43 static void
44 dummy_signal_handler(int signum)
45 {
46 }
47 
48 ATF_TC_WITHOUT_HEAD(arg_validation);
49 ATF_TC_BODY(arg_validation, tc)
50 {
51 	int signum;
52 	int rc;
53 
54 	/* bad signal */
55 	signum = 8888;
56 	rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
57 	ATF_CHECK_EQ(-1, rc);
58 	ATF_CHECK_EQ(EINVAL, errno);
59 
60 	/* bad id type */
61 	signum = SIGINFO;
62 	rc = procctl(8888, 0, PROC_PDEATHSIG_CTL, &signum);
63 	ATF_CHECK_EQ(-1, rc);
64 	ATF_CHECK_EQ(EINVAL, errno);
65 
66 	/* bad id (pid that doesn't match mine or zero) */
67 	signum = SIGINFO;
68 	rc = procctl(P_PID, (((getpid() + 1) % 10) + 100),
69 	    PROC_PDEATHSIG_CTL, &signum);
70 	ATF_CHECK_EQ(-1, rc);
71 	ATF_CHECK_EQ(EINVAL, errno);
72 
73 	/* null pointer */
74 	signum = SIGINFO;
75 	rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, NULL);
76 	ATF_CHECK_EQ(-1, rc);
77 	ATF_CHECK_EQ(EFAULT, errno);
78 
79 	/* good (pid == 0) */
80 	signum = SIGINFO;
81 	rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
82 	ATF_CHECK_EQ(0, rc);
83 
84 	/* good (pid == my pid) */
85 	signum = SIGINFO;
86 	rc = procctl(P_PID, getpid(), PROC_PDEATHSIG_CTL, &signum);
87 	ATF_CHECK_EQ(0, rc);
88 
89 	/* check that we can read the signal number back */
90 	signum = 0xdeadbeef;
91 	rc = procctl(P_PID, 0, PROC_PDEATHSIG_STATUS, &signum);
92 	ATF_CHECK_EQ(0, rc);
93 	ATF_CHECK_EQ(SIGINFO, signum);
94 }
95 
96 ATF_TC_WITHOUT_HEAD(fork_no_inherit);
97 ATF_TC_BODY(fork_no_inherit, tc)
98 {
99 	int status;
100 	int signum;
101 	int rc;
102 
103 	/* request a signal on parent death in the parent */
104 	signum = SIGINFO;
105 	rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
106 
107 	rc = fork();
108 	ATF_REQUIRE(rc != -1);
109 	if (rc == 0) {
110 		/* check that we didn't inherit the setting */
111 		signum = 0xdeadbeef;
112 		rc = procctl(P_PID, 0, PROC_PDEATHSIG_STATUS, &signum);
113 		assert(rc == 0);
114 		assert(signum == 0);
115 		_exit(0);
116 	}
117 
118 	/* wait for the child to exit successfully */
119 	waitpid(rc, &status, 0);
120 	ATF_CHECK_EQ(0, status);
121 }
122 
123 ATF_TC_WITHOUT_HEAD(exec_inherit);
124 ATF_TC_BODY(exec_inherit, tc)
125 {
126 	int status;
127 	int rc;
128 
129 	rc = fork();
130 	ATF_REQUIRE(rc != -1);
131 	if (rc == 0) {
132 		char exec_path[1024];
133 		int signum;
134 
135 		/* compute the path of the helper executable */
136 		snprintf(exec_path, sizeof(exec_path), "%s/pdeathsig_helper",
137 			 atf_tc_get_config_var(tc, "srcdir"));
138 
139 		/* request a signal on parent death and register a handler */
140 		signum = SIGINFO;
141 		rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
142 		assert(rc == 0);
143 
144 		/* execute helper program: it asserts that it has the setting */
145 		rc = execl(exec_path, exec_path, NULL);
146 		assert(rc == 0);
147 		_exit(0);
148 	}
149 
150 	/* wait for the child to exit successfully */
151 	waitpid(rc, &status, 0);
152 	ATF_CHECK_EQ(0, status);
153 }
154 
155 ATF_TC_WITHOUT_HEAD(signal_delivered);
156 ATF_TC_BODY(signal_delivered, tc)
157 {
158 	sigset_t sigset;
159 	int signum;
160 	int rc;
161 	int pipe_ca[2];
162 	int pipe_cb[2];
163 	char buffer;
164 
165 	rc = pipe(pipe_ca);
166 	ATF_REQUIRE(rc == 0);
167 	rc = pipe(pipe_cb);
168 	ATF_REQUIRE(rc == 0);
169 
170 	rc = fork();
171 	ATF_REQUIRE(rc != -1);
172 	if (rc == 0) {
173 		rc = fork();
174 		assert(rc >= 0);
175 		if (rc == 0) {
176 			/* process C */
177 			signum = SIGINFO;
178 
179 			/* block signals so we can handle them synchronously */
180 			rc = sigfillset(&sigset);
181 			assert(rc == 0);
182 			rc = sigprocmask(SIG_SETMASK, &sigset, NULL);
183 			assert(rc == 0);
184 
185 			/* register a dummy handler or the kernel will not queue it */
186 			signal(signum, dummy_signal_handler);
187 
188 			/* request a signal on death of our parent B */
189 			rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
190 			assert(rc == 0);
191 
192 			/* tell B that we're ready for it to exit now */
193 			rc = write(pipe_cb[1], ".", 1);
194 			assert(rc == 1);
195 
196 			/* wait for B to die and signal us... */
197 			signum = 0xdeadbeef;
198 			rc = sigwait(&sigset, &signum);
199 			assert(rc == 0);
200 			assert(signum == SIGINFO);
201 
202 			/* tell A the test passed */
203 			rc = write(pipe_ca[1], ".", 1);
204 			assert(rc == 1);
205 			_exit(0);
206 		}
207 
208 		/* process B */
209 
210 		/* wait for C to tell us it is ready for us to exit */
211 		rc = read(pipe_cb[0], &buffer, 1);
212 		assert(rc == 1);
213 
214 		/* now we exit so that C gets a signal */
215 		_exit(0);
216 	}
217 	/* process A */
218 
219 	/* wait for C to tell us the test passed */
220 	rc = read(pipe_ca[0], &buffer, 1);
221 	ATF_CHECK_EQ(1, rc);
222 }
223 
224 ATF_TC_WITHOUT_HEAD(signal_delivered_ptrace);
225 ATF_TC_BODY(signal_delivered_ptrace, tc)
226 {
227 	sigset_t sigset;
228 	int signum;
229 	int rc;
230 	int pipe_ca[2];
231 	int pipe_db[2];
232 	int pipe_cd[2];
233 	char buffer;
234 	int status;
235 
236 	rc = pipe(pipe_ca);
237 	ATF_REQUIRE(rc == 0);
238 	rc = pipe(pipe_db);
239 	ATF_REQUIRE(rc == 0);
240 	rc = pipe(pipe_cd);
241 	assert(rc == 0);
242 
243 	rc = fork();
244 	ATF_REQUIRE(rc != -1);
245 	if (rc == 0) {
246 		pid_t c_pid;
247 
248 		/* process B */
249 
250 		rc = fork();
251 		assert(rc >= 0);
252 		if (rc == 0) {
253 			/* process C */
254 			signum = SIGINFO;
255 
256 			/* block signals so we can handle them synchronously */
257 			rc = sigfillset(&sigset);
258 			assert(rc == 0);
259 			rc = sigprocmask(SIG_SETMASK, &sigset, NULL);
260 			assert(rc == 0);
261 
262 			/* register a dummy handler or the kernel will not queue it */
263 			signal(signum, dummy_signal_handler);
264 
265 			/* request a signal on parent death and register a handler */
266 			rc = procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &signum);
267 			assert(rc == 0);
268 
269 			rc = write(pipe_cd[1], "x", 1);
270 			assert(rc == 1);
271 
272 			/* wait for B to die and signal us... */
273 			signum = 0xdeadbeef;
274 			rc = sigwait(&sigset, &signum);
275 			assert(rc == 0);
276 			assert(signum == SIGINFO);
277 
278 			/* tell A the test passed */
279 			rc = write(pipe_ca[1], ".", 1);
280 			assert(rc == 1);
281 			_exit(0);
282 		}
283 		c_pid = rc;
284 
285 
286 		/* fork another process to ptrace C */
287 		rc = fork();
288 		assert(rc >= 0);
289 		if (rc == 0) {
290 
291 			/* process D */
292 			rc = ptrace(PT_ATTACH, c_pid, 0, 0);
293 			assert(rc == 0);
294 
295 			waitpid(c_pid, &status, 0);
296 			assert(WIFSTOPPED(status));
297 			assert(WSTOPSIG(status) == SIGSTOP);
298 
299 			rc = ptrace(PT_CONTINUE, c_pid, (caddr_t) 1, 0);
300 			assert(rc == 0);
301 
302 			rc = read(pipe_cd[0], &buffer, 1);
303 			assert(rc == 1);
304 
305 			/* tell B that we're ready for it to exit now */
306 			rc = write(pipe_db[1], ".", 1);
307 			assert(rc == 1);
308 
309 			waitpid(c_pid, &status, 0);
310 			assert(WIFSTOPPED(status));
311 			assert(WSTOPSIG(status) == SIGINFO);
312 
313 			rc = ptrace(PT_CONTINUE, c_pid, (caddr_t) 1,
314 				    WSTOPSIG(status));
315 			assert(rc == 0);
316 
317 			waitpid(c_pid, &status, 0);
318 			if (!WIFEXITED(status))
319 				ptrace(PT_DETACH, c_pid, 0, 0);
320 
321 			_exit(0);
322 		}
323 
324 		/* wait for D to tell us it is ready for us to exit */
325 		rc = read(pipe_db[0], &buffer, 1);
326 		assert(rc == 1);
327 
328 		/* now we exit so that C gets a signal */
329 		_exit(0);
330 	}
331 
332 	/* process A */
333 
334 	/* wait for C to tell us the test passed */
335 	rc = read(pipe_ca[0], &buffer, 1);
336 	ATF_CHECK_EQ(1, rc);
337 }
338 
339 ATF_TP_ADD_TCS(tp)
340 {
341 	ATF_TP_ADD_TC(tp, arg_validation);
342 	ATF_TP_ADD_TC(tp, fork_no_inherit);
343 	ATF_TP_ADD_TC(tp, exec_inherit);
344 	ATF_TP_ADD_TC(tp, signal_delivered);
345 	ATF_TP_ADD_TC(tp, signal_delivered_ptrace);
346 	return (atf_no_error());
347 }
348