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e5ef252a PA |
1 | /* This testcase is part of GDB, the GNU debugger. |
2 | ||
32d0add0 | 3 | Copyright 2010-2015 Free Software Foundation, Inc. |
e5ef252a PA |
4 | |
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | #define _GNU_SOURCE | |
19 | #include <pthread.h> | |
20 | #include <stdio.h> | |
21 | #include <limits.h> | |
22 | #include <errno.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <assert.h> | |
26 | #include <sys/types.h> | |
27 | #include <signal.h> | |
28 | #include <unistd.h> | |
29 | #include <asm/unistd.h> | |
30 | ||
31 | #define gettid() syscall (__NR_gettid) | |
32 | #define tgkill(tgid, tid, sig) syscall (__NR_tgkill, tgid, tid, sig) | |
33 | ||
34 | /* Terminate always in the main task. It can lock up with SIGSTOPped | |
35 | GDB otherwise. */ | |
36 | #define TIMEOUT (gettid () == getpid() ? 10 : 15) | |
37 | ||
38 | static pid_t thread1_tid; | |
39 | static pthread_cond_t thread1_tid_cond | |
40 | = PTHREAD_COND_INITIALIZER; | |
41 | static pthread_mutex_t thread1_tid_mutex | |
42 | = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; | |
43 | static int thread1_sigusr1_hit; | |
44 | static int thread1_sigusr2_hit; | |
45 | ||
46 | static pid_t thread2_tid; | |
47 | static pthread_cond_t thread2_tid_cond | |
48 | = PTHREAD_COND_INITIALIZER; | |
49 | static pthread_mutex_t thread2_tid_mutex | |
50 | = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; | |
51 | static int thread2_sigusr1_hit; | |
52 | static int thread2_sigusr2_hit; | |
53 | ||
54 | static pthread_mutex_t terminate_mutex | |
55 | = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; | |
56 | ||
9665ffdd PA |
57 | static pthread_barrier_t threads_started_barrier; |
58 | ||
e5ef252a PA |
59 | /* Do not use alarm as it would create a ptrace event which would hang |
60 | us up if we are being traced by GDB, which we stopped | |
61 | ourselves. */ | |
62 | ||
63 | static void | |
64 | timed_mutex_lock (pthread_mutex_t *mutex) | |
65 | { | |
66 | int i; | |
67 | struct timespec start, now; | |
68 | ||
69 | i = clock_gettime (CLOCK_MONOTONIC, &start); | |
70 | assert (i == 0); | |
71 | ||
72 | do | |
73 | { | |
74 | i = pthread_mutex_trylock (mutex); | |
75 | if (i == 0) | |
76 | return; | |
77 | assert (i == EBUSY); | |
78 | ||
79 | i = clock_gettime (CLOCK_MONOTONIC, &now); | |
80 | assert (i == 0); | |
81 | assert (now.tv_sec >= start.tv_sec); | |
82 | } | |
83 | while (now.tv_sec - start.tv_sec < TIMEOUT); | |
84 | ||
85 | fprintf (stderr, "Timed out waiting for internal lock!\n"); | |
86 | exit (EXIT_FAILURE); | |
87 | } | |
88 | ||
89 | static void | |
90 | handler (int signo, siginfo_t *siginfo, void *exception) | |
91 | { | |
92 | int *varp; | |
93 | ||
94 | assert (siginfo->si_signo == signo); | |
95 | assert (siginfo->si_code == SI_TKILL); | |
96 | assert (siginfo->si_pid == getpid ()); | |
97 | ||
98 | if (gettid () == thread1_tid) | |
99 | { | |
100 | if (signo == SIGUSR1) | |
101 | varp = &thread1_sigusr1_hit; | |
102 | else if (signo == SIGUSR2) | |
103 | varp = &thread1_sigusr2_hit; | |
104 | else | |
105 | assert (0); | |
106 | } | |
107 | else if (gettid () == thread2_tid) | |
108 | { | |
109 | if (signo == SIGUSR1) | |
110 | varp = &thread2_sigusr1_hit; | |
111 | else if (signo == SIGUSR2) | |
112 | varp = &thread2_sigusr2_hit; | |
113 | else | |
114 | assert (0); | |
115 | } | |
116 | else | |
117 | assert (0); | |
118 | ||
119 | if (*varp) | |
120 | { | |
121 | fprintf (stderr, "Signal %d for TID %lu has been already hit!\n", signo, | |
122 | (unsigned long) gettid ()); | |
123 | exit (EXIT_FAILURE); | |
124 | } | |
125 | *varp = 1; | |
126 | } | |
127 | ||
128 | static void * | |
129 | thread1_func (void *unused) | |
130 | { | |
131 | int i; | |
132 | ||
9665ffdd PA |
133 | pthread_barrier_wait (&threads_started_barrier); |
134 | ||
e5ef252a PA |
135 | timed_mutex_lock (&thread1_tid_mutex); |
136 | ||
137 | /* THREAD1_TID_MUTEX must be already locked to avoid a race. */ | |
138 | thread1_tid = gettid (); | |
139 | ||
140 | i = pthread_cond_signal (&thread1_tid_cond); | |
141 | assert (i == 0); | |
142 | i = pthread_mutex_unlock (&thread1_tid_mutex); | |
143 | assert (i == 0); | |
144 | ||
145 | /* Be sure the "t (tracing stop)" test can proceed for both | |
146 | threads. */ | |
147 | timed_mutex_lock (&terminate_mutex); | |
148 | i = pthread_mutex_unlock (&terminate_mutex); | |
149 | assert (i == 0); | |
150 | ||
151 | if (!thread1_sigusr1_hit) | |
152 | { | |
153 | fprintf (stderr, "Thread 1 signal SIGUSR1 not hit!\n"); | |
154 | exit (EXIT_FAILURE); | |
155 | } | |
156 | if (!thread1_sigusr2_hit) | |
157 | { | |
158 | fprintf (stderr, "Thread 1 signal SIGUSR2 not hit!\n"); | |
159 | exit (EXIT_FAILURE); | |
160 | } | |
161 | ||
162 | return NULL; | |
163 | } | |
164 | ||
165 | static void * | |
166 | thread2_func (void *unused) | |
167 | { | |
168 | int i; | |
169 | ||
9665ffdd PA |
170 | pthread_barrier_wait (&threads_started_barrier); |
171 | ||
e5ef252a PA |
172 | timed_mutex_lock (&thread2_tid_mutex); |
173 | ||
174 | /* THREAD2_TID_MUTEX must be already locked to avoid a race. */ | |
175 | thread2_tid = gettid (); | |
176 | ||
177 | i = pthread_cond_signal (&thread2_tid_cond); | |
178 | assert (i == 0); | |
179 | i = pthread_mutex_unlock (&thread2_tid_mutex); | |
180 | assert (i == 0); | |
181 | ||
182 | /* Be sure the "t (tracing stop)" test can proceed for both | |
183 | threads. */ | |
184 | timed_mutex_lock (&terminate_mutex); | |
185 | i = pthread_mutex_unlock (&terminate_mutex); | |
186 | assert (i == 0); | |
187 | ||
188 | if (!thread2_sigusr1_hit) | |
189 | { | |
190 | fprintf (stderr, "Thread 2 signal SIGUSR1 not hit!\n"); | |
191 | exit (EXIT_FAILURE); | |
192 | } | |
193 | if (!thread2_sigusr2_hit) | |
194 | { | |
195 | fprintf (stderr, "Thread 2 signal SIGUSR2 not hit!\n"); | |
196 | exit (EXIT_FAILURE); | |
197 | } | |
198 | ||
199 | return NULL; | |
200 | } | |
201 | ||
202 | static const char * | |
203 | proc_string (const char *filename, const char *line) | |
204 | { | |
205 | FILE *f; | |
206 | static char buf[LINE_MAX]; | |
207 | size_t line_len = strlen (line); | |
208 | ||
209 | f = fopen (filename, "r"); | |
210 | if (f == NULL) | |
211 | { | |
212 | fprintf (stderr, "fopen (\"%s\") for \"%s\": %s\n", filename, line, | |
213 | strerror (errno)); | |
214 | exit (EXIT_FAILURE); | |
215 | } | |
216 | while (errno = 0, fgets (buf, sizeof (buf), f)) | |
217 | { | |
218 | char *s; | |
219 | ||
220 | s = strchr (buf, '\n'); | |
221 | assert (s != NULL); | |
222 | *s = 0; | |
223 | ||
224 | if (strncmp (buf, line, line_len) != 0) | |
225 | continue; | |
226 | ||
227 | if (fclose (f)) | |
228 | { | |
229 | fprintf (stderr, "fclose (\"%s\") for \"%s\": %s\n", filename, line, | |
230 | strerror (errno)); | |
231 | exit (EXIT_FAILURE); | |
232 | } | |
233 | ||
234 | return &buf[line_len]; | |
235 | } | |
236 | if (errno != 0) | |
237 | { | |
238 | fprintf (stderr, "fgets (\"%s\": %s\n", filename, strerror (errno)); | |
239 | exit (EXIT_FAILURE); | |
240 | } | |
241 | fprintf (stderr, "\"%s\": No line \"%s\" found.\n", filename, line); | |
242 | exit (EXIT_FAILURE); | |
243 | } | |
244 | ||
245 | static unsigned long | |
246 | proc_ulong (const char *filename, const char *line) | |
247 | { | |
248 | const char *s = proc_string (filename, line); | |
249 | long retval; | |
250 | char *end; | |
251 | ||
252 | errno = 0; | |
253 | retval = strtol (s, &end, 10); | |
254 | if (retval < 0 || retval >= LONG_MAX || (end && *end)) | |
255 | { | |
256 | fprintf (stderr, "\"%s\":\"%s\": %ld, %s\n", filename, line, retval, | |
257 | strerror (errno)); | |
258 | exit (EXIT_FAILURE); | |
259 | } | |
260 | return retval; | |
261 | } | |
262 | ||
263 | static void | |
264 | state_wait (pid_t process, const char *wanted) | |
265 | { | |
266 | char *filename; | |
267 | int i; | |
268 | struct timespec start, now; | |
269 | const char *state; | |
270 | ||
271 | i = asprintf (&filename, "/proc/%lu/status", (unsigned long) process); | |
272 | assert (i > 0); | |
273 | ||
274 | i = clock_gettime (CLOCK_MONOTONIC, &start); | |
275 | assert (i == 0); | |
276 | ||
277 | do | |
278 | { | |
279 | state = proc_string (filename, "State:\t"); | |
280 | ||
281 | /* torvalds/linux-2.6.git 464763cf1c6df632dccc8f2f4c7e50163154a2c0 | |
282 | has changed "T (tracing stop)" to "t (tracing stop)". Make the GDB | |
283 | testcase backward compatible with older Linux kernels. */ | |
284 | if (strcmp (state, "T (tracing stop)") == 0) | |
285 | state = "t (tracing stop)"; | |
286 | ||
287 | if (strcmp (state, wanted) == 0) | |
288 | { | |
289 | free (filename); | |
290 | return; | |
291 | } | |
292 | ||
293 | if (sched_yield ()) | |
294 | { | |
295 | perror ("sched_yield()"); | |
296 | exit (EXIT_FAILURE); | |
297 | } | |
298 | ||
299 | i = clock_gettime (CLOCK_MONOTONIC, &now); | |
300 | assert (i == 0); | |
301 | assert (now.tv_sec >= start.tv_sec); | |
302 | } | |
303 | while (now.tv_sec - start.tv_sec < TIMEOUT); | |
304 | ||
305 | fprintf (stderr, "Timed out waiting for PID %lu \"%s\" (now it is \"%s\")!\n", | |
306 | (unsigned long) process, wanted, state); | |
307 | exit (EXIT_FAILURE); | |
308 | } | |
309 | ||
310 | static volatile pid_t tracer = 0; | |
311 | static pthread_t thread1, thread2; | |
312 | ||
313 | static void | |
314 | cleanup (void) | |
315 | { | |
316 | printf ("Resuming GDB PID %lu.\n", (unsigned long) tracer); | |
317 | ||
318 | if (tracer) | |
319 | { | |
320 | int i; | |
321 | int tracer_save = tracer; | |
322 | ||
323 | tracer = 0; | |
324 | ||
325 | i = kill (tracer_save, SIGCONT); | |
326 | assert (i == 0); | |
327 | } | |
328 | } | |
329 | ||
330 | int | |
331 | main (int argc, char **argv) | |
332 | { | |
333 | int i; | |
334 | int standalone = 0; | |
335 | struct sigaction act; | |
336 | ||
337 | if (argc == 2 && strcmp (argv[1], "-s") == 0) | |
338 | standalone = 1; | |
339 | else | |
340 | assert (argc == 1); | |
341 | ||
342 | setbuf (stdout, NULL); | |
343 | ||
344 | timed_mutex_lock (&thread1_tid_mutex); | |
345 | timed_mutex_lock (&thread2_tid_mutex); | |
346 | ||
347 | timed_mutex_lock (&terminate_mutex); | |
348 | ||
349 | errno = 0; | |
350 | memset (&act, 0, sizeof (act)); | |
351 | act.sa_sigaction = handler; | |
352 | act.sa_flags = SA_RESTART | SA_SIGINFO; | |
353 | i = sigemptyset (&act.sa_mask); | |
354 | assert_perror (errno); | |
355 | assert (i == 0); | |
356 | i = sigaction (SIGUSR1, &act, NULL); | |
357 | assert_perror (errno); | |
358 | assert (i == 0); | |
359 | i = sigaction (SIGUSR2, &act, NULL); | |
360 | assert_perror (errno); | |
361 | assert (i == 0); | |
362 | ||
9665ffdd PA |
363 | pthread_barrier_init (&threads_started_barrier, NULL, 3); |
364 | ||
e5ef252a PA |
365 | i = pthread_create (&thread1, NULL, thread1_func, NULL); |
366 | assert (i == 0); | |
367 | ||
368 | i = pthread_create (&thread2, NULL, thread2_func, NULL); | |
369 | assert (i == 0); | |
370 | ||
371 | if (!standalone) | |
372 | { | |
373 | tracer = proc_ulong ("/proc/self/status", "TracerPid:\t"); | |
374 | if (tracer == 0) | |
375 | { | |
376 | fprintf (stderr, "The testcase must be run by GDB!\n"); | |
377 | exit (EXIT_FAILURE); | |
378 | } | |
379 | if (tracer != getppid ()) | |
380 | { | |
381 | fprintf (stderr, "The testcase parent must be our GDB tracer!\n"); | |
382 | exit (EXIT_FAILURE); | |
383 | } | |
384 | } | |
385 | ||
386 | /* SIGCONT our debugger in the case of our crash as we would deadlock | |
387 | otherwise. */ | |
388 | ||
389 | atexit (cleanup); | |
390 | ||
9665ffdd PA |
391 | /* Wait until all threads are seen running. On Linux (at least), |
392 | new threads start stopped, and the debugger must resume them. | |
393 | Need to wait for that before stopping GDB. */ | |
394 | pthread_barrier_wait (&threads_started_barrier); | |
395 | ||
e5ef252a PA |
396 | printf ("Stopping GDB PID %lu.\n", (unsigned long) tracer); |
397 | ||
398 | if (tracer) | |
399 | { | |
400 | i = kill (tracer, SIGSTOP); | |
401 | assert (i == 0); | |
402 | state_wait (tracer, "T (stopped)"); | |
403 | } | |
404 | ||
405 | /* Threads are now waiting at timed_mutex_lock (thread1_tid_mutex) | |
406 | and so they could not trigger the signals before GDB is unstopped | |
407 | later. Threads get resumed by the pthread_cond_wait below. Use | |
408 | `while' loops for protection against spurious pthread_cond_wait | |
409 | wakeups. */ | |
410 | ||
411 | printf ("Waiting till the threads initialize their TIDs.\n"); | |
412 | ||
413 | while (thread1_tid == 0) | |
414 | { | |
415 | i = pthread_cond_wait (&thread1_tid_cond, &thread1_tid_mutex); | |
416 | assert (i == 0); | |
417 | } | |
418 | ||
419 | while (thread2_tid == 0) | |
420 | { | |
421 | i = pthread_cond_wait (&thread2_tid_cond, &thread2_tid_mutex); | |
422 | assert (i == 0); | |
423 | } | |
424 | ||
425 | printf ("Thread 1 TID = %lu, thread 2 TID = %lu, PID = %lu.\n", | |
426 | (unsigned long) thread1_tid, (unsigned long) thread2_tid, | |
427 | (unsigned long) getpid ()); | |
428 | ||
429 | errno = 0; | |
430 | i = tgkill (getpid (), thread1_tid, SIGUSR1); | |
431 | assert_perror (errno); | |
432 | assert (i == 0); | |
433 | i = tgkill (getpid (), thread1_tid, SIGUSR2); | |
434 | assert_perror (errno); | |
435 | assert (i == 0); | |
436 | i = tgkill (getpid (), thread2_tid, SIGUSR1); | |
437 | assert_perror (errno); | |
438 | assert (i == 0); | |
439 | i = tgkill (getpid (), thread2_tid, SIGUSR2); | |
440 | assert_perror (errno); | |
441 | assert (i == 0); | |
442 | ||
443 | printf ("Waiting till the threads are trapped by the signals.\n"); | |
444 | ||
445 | if (tracer) | |
446 | { | |
447 | /* s390x-unknown-linux-gnu will fail with "R (running)". */ | |
448 | ||
449 | state_wait (thread1_tid, "t (tracing stop)"); | |
450 | ||
451 | state_wait (thread2_tid, "t (tracing stop)"); | |
452 | } | |
453 | ||
454 | cleanup (); | |
455 | ||
456 | printf ("Joining the threads.\n"); | |
457 | ||
458 | i = pthread_mutex_unlock (&terminate_mutex); | |
459 | assert (i == 0); | |
460 | ||
461 | i = pthread_join (thread1, NULL); | |
462 | assert (i == 0); | |
463 | ||
464 | i = pthread_join (thread2, NULL); | |
465 | assert (i == 0); | |
466 | ||
467 | printf ("Exiting.\n"); /* break-at-exit */ | |
468 | ||
469 | return EXIT_SUCCESS; | |
470 | } |