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26ab7092 JK |
1 | /* This testcase is part of GDB, the GNU debugger. |
2 | ||
32d0add0 | 3 | Copyright 2010-2015 Free Software Foundation, Inc. |
26ab7092 JK |
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 | ||
33 | /* Terminate always in the main task, it can lock up with SIGSTOPped GDB | |
34 | otherwise. */ | |
35 | #define TIMEOUT (gettid () == getpid() ? 10 : 15) | |
36 | ||
37 | static pid_t thread1_tid; | |
38 | static pthread_cond_t thread1_tid_cond = PTHREAD_COND_INITIALIZER; | |
39 | static pthread_mutex_t thread1_tid_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; | |
40 | ||
41 | static pid_t thread2_tid; | |
42 | static pthread_cond_t thread2_tid_cond = PTHREAD_COND_INITIALIZER; | |
43 | static pthread_mutex_t thread2_tid_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; | |
44 | ||
45 | static pthread_mutex_t terminate_mutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; | |
46 | ||
9665ffdd PA |
47 | static pthread_barrier_t threads_started_barrier; |
48 | ||
26ab7092 JK |
49 | /* Do not use alarm as it would create a ptrace event which would hang up us if |
50 | we are being traced by GDB which we stopped ourselves. */ | |
51 | ||
52 | static void timed_mutex_lock (pthread_mutex_t *mutex) | |
53 | { | |
54 | int i; | |
55 | struct timespec start, now; | |
56 | ||
57 | i = clock_gettime (CLOCK_MONOTONIC, &start); | |
58 | assert (i == 0); | |
59 | ||
60 | do | |
61 | { | |
62 | i = pthread_mutex_trylock (mutex); | |
63 | if (i == 0) | |
64 | return; | |
65 | assert (i == EBUSY); | |
66 | ||
67 | i = clock_gettime (CLOCK_MONOTONIC, &now); | |
68 | assert (i == 0); | |
69 | assert (now.tv_sec >= start.tv_sec); | |
70 | } | |
71 | while (now.tv_sec - start.tv_sec < TIMEOUT); | |
72 | ||
73 | fprintf (stderr, "Timed out waiting for internal lock!\n"); | |
74 | exit (EXIT_FAILURE); | |
75 | } | |
76 | ||
77 | static void * | |
78 | thread_func (void *threadno_voidp) | |
79 | { | |
80 | int threadno = (intptr_t) threadno_voidp; | |
81 | int i; | |
82 | ||
9665ffdd PA |
83 | pthread_barrier_wait (&threads_started_barrier); |
84 | ||
26ab7092 JK |
85 | switch (threadno) |
86 | { | |
87 | case 1: | |
88 | timed_mutex_lock (&thread1_tid_mutex); | |
89 | ||
90 | /* THREAD1_TID_MUTEX must be already locked to avoid race. */ | |
91 | thread1_tid = gettid (); | |
92 | ||
93 | i = pthread_cond_signal (&thread1_tid_cond); | |
94 | assert (i == 0); | |
95 | i = pthread_mutex_unlock (&thread1_tid_mutex); | |
96 | assert (i == 0); | |
97 | ||
98 | break; | |
99 | ||
100 | case 2: | |
101 | timed_mutex_lock (&thread2_tid_mutex); | |
102 | ||
103 | /* THREAD2_TID_MUTEX must be already locked to avoid race. */ | |
104 | thread2_tid = gettid (); | |
105 | ||
106 | i = pthread_cond_signal (&thread2_tid_cond); | |
107 | assert (i == 0); | |
108 | i = pthread_mutex_unlock (&thread2_tid_mutex); | |
109 | assert (i == 0); | |
110 | ||
111 | break; | |
112 | ||
113 | default: | |
114 | assert (0); | |
115 | } | |
116 | ||
117 | #ifdef __ia64__ | |
118 | asm volatile ("label:\n" | |
119 | "nop.m 0\n" | |
120 | "nop.i 0\n" | |
121 | "nop.b 0\n"); | |
122 | #endif | |
123 | /* break-here */ | |
124 | ||
125 | /* Be sure the "t (tracing stop)" test can proceed for both threads. */ | |
126 | timed_mutex_lock (&terminate_mutex); | |
127 | i = pthread_mutex_unlock (&terminate_mutex); | |
128 | assert (i == 0); | |
129 | ||
130 | return NULL; | |
131 | } | |
132 | ||
133 | static const char * | |
134 | proc_string (const char *filename, const char *line) | |
135 | { | |
136 | FILE *f; | |
137 | static char buf[LINE_MAX]; | |
138 | size_t line_len = strlen (line); | |
139 | ||
140 | f = fopen (filename, "r"); | |
141 | if (f == NULL) | |
142 | { | |
143 | fprintf (stderr, "fopen (\"%s\") for \"%s\": %s\n", filename, line, | |
144 | strerror (errno)); | |
145 | exit (EXIT_FAILURE); | |
146 | } | |
147 | while (errno = 0, fgets (buf, sizeof (buf), f)) | |
148 | { | |
149 | char *s; | |
150 | ||
151 | s = strchr (buf, '\n'); | |
152 | assert (s != NULL); | |
153 | *s = 0; | |
154 | ||
155 | if (strncmp (buf, line, line_len) != 0) | |
156 | continue; | |
157 | ||
158 | if (fclose (f)) | |
159 | { | |
160 | fprintf (stderr, "fclose (\"%s\") for \"%s\": %s\n", filename, line, | |
161 | strerror (errno)); | |
162 | exit (EXIT_FAILURE); | |
163 | } | |
164 | ||
165 | return &buf[line_len]; | |
166 | } | |
167 | if (errno != 0) | |
168 | { | |
169 | fprintf (stderr, "fgets (\"%s\": %s\n", filename, strerror (errno)); | |
170 | exit (EXIT_FAILURE); | |
171 | } | |
172 | fprintf (stderr, "\"%s\": No line \"%s\" found.\n", filename, line); | |
173 | exit (EXIT_FAILURE); | |
174 | } | |
175 | ||
176 | static unsigned long | |
177 | proc_ulong (const char *filename, const char *line) | |
178 | { | |
179 | const char *s = proc_string (filename, line); | |
180 | long retval; | |
181 | char *end; | |
182 | ||
183 | errno = 0; | |
184 | retval = strtol (s, &end, 10); | |
185 | if (retval < 0 || retval >= LONG_MAX || (end && *end)) | |
186 | { | |
187 | fprintf (stderr, "\"%s\":\"%s\": %ld, %s\n", filename, line, retval, | |
188 | strerror (errno)); | |
189 | exit (EXIT_FAILURE); | |
190 | } | |
191 | return retval; | |
192 | } | |
193 | ||
194 | static void | |
195 | state_wait (pid_t process, const char *wanted) | |
196 | { | |
197 | char *filename; | |
198 | int i; | |
199 | struct timespec start, now; | |
200 | const char *state; | |
201 | ||
202 | i = asprintf (&filename, "/proc/%lu/status", (unsigned long) process); | |
203 | assert (i > 0); | |
204 | ||
205 | i = clock_gettime (CLOCK_MONOTONIC, &start); | |
206 | assert (i == 0); | |
207 | ||
208 | do | |
209 | { | |
210 | state = proc_string (filename, "State:\t"); | |
211 | ||
212 | /* torvalds/linux-2.6.git 464763cf1c6df632dccc8f2f4c7e50163154a2c0 | |
213 | has changed "T (tracing stop)" to "t (tracing stop)". Make the GDB | |
214 | testcase backward compatible with older Linux kernels. */ | |
215 | if (strcmp (state, "T (tracing stop)") == 0) | |
216 | state = "t (tracing stop)"; | |
217 | ||
218 | if (strcmp (state, wanted) == 0) | |
219 | { | |
220 | free (filename); | |
221 | return; | |
222 | } | |
223 | ||
224 | if (sched_yield ()) | |
225 | { | |
226 | perror ("sched_yield()"); | |
227 | exit (EXIT_FAILURE); | |
228 | } | |
229 | ||
230 | i = clock_gettime (CLOCK_MONOTONIC, &now); | |
231 | assert (i == 0); | |
232 | assert (now.tv_sec >= start.tv_sec); | |
233 | } | |
234 | while (now.tv_sec - start.tv_sec < TIMEOUT); | |
235 | ||
236 | fprintf (stderr, "Timed out waiting for PID %lu \"%s\" (now it is \"%s\")!\n", | |
237 | (unsigned long) process, wanted, state); | |
238 | exit (EXIT_FAILURE); | |
239 | } | |
240 | ||
241 | static volatile pid_t tracer = 0; | |
242 | static pthread_t thread1, thread2; | |
243 | ||
244 | static void | |
245 | cleanup (void) | |
246 | { | |
247 | printf ("Resuming GDB PID %lu.\n", (unsigned long) tracer); | |
248 | ||
249 | if (tracer) | |
250 | { | |
251 | int i; | |
252 | int tracer_save = tracer; | |
253 | ||
254 | tracer = 0; | |
255 | ||
256 | i = kill (tracer_save, SIGCONT); | |
257 | assert (i == 0); | |
258 | } | |
259 | } | |
260 | ||
261 | int | |
262 | main (int argc, char **argv) | |
263 | { | |
264 | int i; | |
265 | int standalone = 0; | |
266 | ||
267 | if (argc == 2 && strcmp (argv[1], "-s") == 0) | |
268 | standalone = 1; | |
269 | else | |
270 | assert (argc == 1); | |
271 | ||
272 | setbuf (stdout, NULL); | |
273 | ||
274 | timed_mutex_lock (&thread1_tid_mutex); | |
275 | timed_mutex_lock (&thread2_tid_mutex); | |
276 | ||
277 | timed_mutex_lock (&terminate_mutex); | |
278 | ||
9665ffdd PA |
279 | pthread_barrier_init (&threads_started_barrier, NULL, 3); |
280 | ||
26ab7092 JK |
281 | i = pthread_create (&thread1, NULL, thread_func, (void *) (intptr_t) 1); |
282 | assert (i == 0); | |
283 | ||
284 | i = pthread_create (&thread2, NULL, thread_func, (void *) (intptr_t) 2); | |
285 | assert (i == 0); | |
286 | ||
287 | if (!standalone) | |
288 | { | |
289 | tracer = proc_ulong ("/proc/self/status", "TracerPid:\t"); | |
290 | if (tracer == 0) | |
291 | { | |
292 | fprintf (stderr, "The testcase must be run by GDB!\n"); | |
293 | exit (EXIT_FAILURE); | |
294 | } | |
295 | if (tracer != getppid ()) | |
296 | { | |
297 | fprintf (stderr, "The testcase parent must be our GDB tracer!\n"); | |
298 | exit (EXIT_FAILURE); | |
299 | } | |
300 | } | |
301 | ||
302 | /* SIGCONT our debugger in the case of our crash as we would deadlock | |
303 | otherwise. */ | |
304 | ||
305 | atexit (cleanup); | |
306 | ||
9665ffdd PA |
307 | /* Wait until all threads are seen running. On Linux (at least), |
308 | new threads start stopped, and the debugger must resume them. | |
309 | Need to wait for that before stopping GDB. */ | |
310 | pthread_barrier_wait (&threads_started_barrier); | |
311 | ||
26ab7092 JK |
312 | printf ("Stopping GDB PID %lu.\n", (unsigned long) tracer); |
313 | ||
314 | if (tracer) | |
315 | { | |
316 | i = kill (tracer, SIGSTOP); | |
317 | assert (i == 0); | |
318 | state_wait (tracer, "T (stopped)"); | |
319 | } | |
320 | ||
321 | /* Threads are now waiting at timed_mutex_lock (thread1_tid_mutex) and so | |
322 | they could not trigger the breakpoint before GDB gets unstopped later. | |
323 | Threads get resumed at pthread_cond_wait below. Use `while' loops for | |
324 | protection against spurious pthread_cond_wait wakeups. */ | |
325 | ||
326 | printf ("Waiting till the threads initialize their TIDs.\n"); | |
327 | ||
328 | while (thread1_tid == 0) | |
329 | { | |
330 | i = pthread_cond_wait (&thread1_tid_cond, &thread1_tid_mutex); | |
331 | assert (i == 0); | |
332 | } | |
333 | ||
334 | while (thread2_tid == 0) | |
335 | { | |
336 | i = pthread_cond_wait (&thread2_tid_cond, &thread2_tid_mutex); | |
337 | assert (i == 0); | |
338 | } | |
339 | ||
340 | printf ("Thread 1 TID = %lu, thread 2 TID = %lu, PID = %lu.\n", | |
341 | (unsigned long) thread1_tid, (unsigned long) thread2_tid, | |
342 | (unsigned long) getpid ()); | |
343 | ||
344 | printf ("Waiting till the threads get trapped by the breakpoint.\n"); | |
345 | ||
346 | if (tracer) | |
347 | { | |
348 | /* s390x-unknown-linux-gnu will fail with "R (running)". */ | |
349 | ||
350 | state_wait (thread1_tid, "t (tracing stop)"); | |
351 | ||
352 | state_wait (thread2_tid, "t (tracing stop)"); | |
353 | } | |
354 | ||
355 | cleanup (); | |
356 | ||
357 | printf ("Joining the threads.\n"); | |
358 | ||
359 | i = pthread_mutex_unlock (&terminate_mutex); | |
360 | assert (i == 0); | |
361 | ||
362 | i = pthread_join (thread1, NULL); | |
363 | assert (i == 0); | |
364 | ||
365 | i = pthread_join (thread2, NULL); | |
366 | assert (i == 0); | |
367 | ||
368 | printf ("Exiting.\n"); /* break-at-exit */ | |
369 | ||
370 | return EXIT_SUCCESS; | |
371 | } |