1 /* This testcase is part of GDB, the GNU debugger.
3 Copyright 2010-2014 Free Software Foundation, Inc.
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.
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.
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/>. */
26 #include <sys/types.h>
29 #include <asm/unistd.h>
31 #define gettid() syscall (__NR_gettid)
33 /* Terminate always in the main task, it can lock up with SIGSTOPped GDB
35 #define TIMEOUT (gettid () == getpid() ? 10 : 15)
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
;
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
;
45 static pthread_mutex_t terminate_mutex
= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
;
47 /* Do not use alarm as it would create a ptrace event which would hang up us if
48 we are being traced by GDB which we stopped ourselves. */
50 static void timed_mutex_lock (pthread_mutex_t
*mutex
)
53 struct timespec start
, now
;
55 i
= clock_gettime (CLOCK_MONOTONIC
, &start
);
60 i
= pthread_mutex_trylock (mutex
);
65 i
= clock_gettime (CLOCK_MONOTONIC
, &now
);
67 assert (now
.tv_sec
>= start
.tv_sec
);
69 while (now
.tv_sec
- start
.tv_sec
< TIMEOUT
);
71 fprintf (stderr
, "Timed out waiting for internal lock!\n");
76 thread_func (void *threadno_voidp
)
78 int threadno
= (intptr_t) threadno_voidp
;
84 timed_mutex_lock (&thread1_tid_mutex
);
86 /* THREAD1_TID_MUTEX must be already locked to avoid race. */
87 thread1_tid
= gettid ();
89 i
= pthread_cond_signal (&thread1_tid_cond
);
91 i
= pthread_mutex_unlock (&thread1_tid_mutex
);
97 timed_mutex_lock (&thread2_tid_mutex
);
99 /* THREAD2_TID_MUTEX must be already locked to avoid race. */
100 thread2_tid
= gettid ();
102 i
= pthread_cond_signal (&thread2_tid_cond
);
104 i
= pthread_mutex_unlock (&thread2_tid_mutex
);
114 asm volatile ("label:\n"
121 /* Be sure the "t (tracing stop)" test can proceed for both threads. */
122 timed_mutex_lock (&terminate_mutex
);
123 i
= pthread_mutex_unlock (&terminate_mutex
);
130 proc_string (const char *filename
, const char *line
)
133 static char buf
[LINE_MAX
];
134 size_t line_len
= strlen (line
);
136 f
= fopen (filename
, "r");
139 fprintf (stderr
, "fopen (\"%s\") for \"%s\": %s\n", filename
, line
,
143 while (errno
= 0, fgets (buf
, sizeof (buf
), f
))
147 s
= strchr (buf
, '\n');
151 if (strncmp (buf
, line
, line_len
) != 0)
156 fprintf (stderr
, "fclose (\"%s\") for \"%s\": %s\n", filename
, line
,
161 return &buf
[line_len
];
165 fprintf (stderr
, "fgets (\"%s\": %s\n", filename
, strerror (errno
));
168 fprintf (stderr
, "\"%s\": No line \"%s\" found.\n", filename
, line
);
173 proc_ulong (const char *filename
, const char *line
)
175 const char *s
= proc_string (filename
, line
);
180 retval
= strtol (s
, &end
, 10);
181 if (retval
< 0 || retval
>= LONG_MAX
|| (end
&& *end
))
183 fprintf (stderr
, "\"%s\":\"%s\": %ld, %s\n", filename
, line
, retval
,
191 state_wait (pid_t process
, const char *wanted
)
195 struct timespec start
, now
;
198 i
= asprintf (&filename
, "/proc/%lu/status", (unsigned long) process
);
201 i
= clock_gettime (CLOCK_MONOTONIC
, &start
);
206 state
= proc_string (filename
, "State:\t");
208 /* torvalds/linux-2.6.git 464763cf1c6df632dccc8f2f4c7e50163154a2c0
209 has changed "T (tracing stop)" to "t (tracing stop)". Make the GDB
210 testcase backward compatible with older Linux kernels. */
211 if (strcmp (state
, "T (tracing stop)") == 0)
212 state
= "t (tracing stop)";
214 if (strcmp (state
, wanted
) == 0)
222 perror ("sched_yield()");
226 i
= clock_gettime (CLOCK_MONOTONIC
, &now
);
228 assert (now
.tv_sec
>= start
.tv_sec
);
230 while (now
.tv_sec
- start
.tv_sec
< TIMEOUT
);
232 fprintf (stderr
, "Timed out waiting for PID %lu \"%s\" (now it is \"%s\")!\n",
233 (unsigned long) process
, wanted
, state
);
237 static volatile pid_t tracer
= 0;
238 static pthread_t thread1
, thread2
;
243 printf ("Resuming GDB PID %lu.\n", (unsigned long) tracer
);
248 int tracer_save
= tracer
;
252 i
= kill (tracer_save
, SIGCONT
);
258 main (int argc
, char **argv
)
263 if (argc
== 2 && strcmp (argv
[1], "-s") == 0)
268 setbuf (stdout
, NULL
);
270 timed_mutex_lock (&thread1_tid_mutex
);
271 timed_mutex_lock (&thread2_tid_mutex
);
273 timed_mutex_lock (&terminate_mutex
);
275 i
= pthread_create (&thread1
, NULL
, thread_func
, (void *) (intptr_t) 1);
278 i
= pthread_create (&thread2
, NULL
, thread_func
, (void *) (intptr_t) 2);
283 tracer
= proc_ulong ("/proc/self/status", "TracerPid:\t");
286 fprintf (stderr
, "The testcase must be run by GDB!\n");
289 if (tracer
!= getppid ())
291 fprintf (stderr
, "The testcase parent must be our GDB tracer!\n");
296 /* SIGCONT our debugger in the case of our crash as we would deadlock
301 printf ("Stopping GDB PID %lu.\n", (unsigned long) tracer
);
305 i
= kill (tracer
, SIGSTOP
);
307 state_wait (tracer
, "T (stopped)");
310 /* Threads are now waiting at timed_mutex_lock (thread1_tid_mutex) and so
311 they could not trigger the breakpoint before GDB gets unstopped later.
312 Threads get resumed at pthread_cond_wait below. Use `while' loops for
313 protection against spurious pthread_cond_wait wakeups. */
315 printf ("Waiting till the threads initialize their TIDs.\n");
317 while (thread1_tid
== 0)
319 i
= pthread_cond_wait (&thread1_tid_cond
, &thread1_tid_mutex
);
323 while (thread2_tid
== 0)
325 i
= pthread_cond_wait (&thread2_tid_cond
, &thread2_tid_mutex
);
329 printf ("Thread 1 TID = %lu, thread 2 TID = %lu, PID = %lu.\n",
330 (unsigned long) thread1_tid
, (unsigned long) thread2_tid
,
331 (unsigned long) getpid ());
333 printf ("Waiting till the threads get trapped by the breakpoint.\n");
337 /* s390x-unknown-linux-gnu will fail with "R (running)". */
339 state_wait (thread1_tid
, "t (tracing stop)");
341 state_wait (thread2_tid
, "t (tracing stop)");
346 printf ("Joining the threads.\n");
348 i
= pthread_mutex_unlock (&terminate_mutex
);
351 i
= pthread_join (thread1
, NULL
);
354 i
= pthread_join (thread2
, NULL
);
357 printf ("Exiting.\n"); /* break-at-exit */