1
/* This testcase is part of GDB, the GNU debugger.
3
Copyright 2009, 2010 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
/* These variables must have lower in-memory addresses than thread1_rwatch and
48
thread2_rwatch so that they take their watchpoint slots. */
50
static int unused1_rwatch;
51
static int unused2_rwatch;
53
static volatile int thread1_rwatch;
54
static volatile int thread2_rwatch;
56
/* Do not use alarm as it would create a ptrace event which would hang up us if
57
we are being traced by GDB which we stopped ourselves. */
59
static void timed_mutex_lock (pthread_mutex_t *mutex)
62
struct timespec start, now;
64
i = clock_gettime (CLOCK_MONOTONIC, &start);
69
i = pthread_mutex_trylock (mutex);
74
i = clock_gettime (CLOCK_MONOTONIC, &now);
76
assert (now.tv_sec >= start.tv_sec);
78
while (now.tv_sec - start.tv_sec < TIMEOUT);
80
fprintf (stderr, "Timed out waiting for internal lock!\n");
85
thread1_func (void *unused)
88
volatile int rwatch_store;
90
timed_mutex_lock (&thread1_tid_mutex);
92
/* THREAD1_TID_MUTEX must be already locked to avoid race. */
93
thread1_tid = gettid ();
95
i = pthread_cond_signal (&thread1_tid_cond);
97
i = pthread_mutex_unlock (&thread1_tid_mutex);
100
rwatch_store = thread1_rwatch;
102
/* Be sure the "T (tracing stop)" test can proceed for both threads. */
103
timed_mutex_lock (&terminate_mutex);
104
i = pthread_mutex_unlock (&terminate_mutex);
111
thread2_func (void *unused)
114
volatile int rwatch_store;
116
timed_mutex_lock (&thread2_tid_mutex);
118
/* THREAD2_TID_MUTEX must be already locked to avoid race. */
119
thread2_tid = gettid ();
121
i = pthread_cond_signal (&thread2_tid_cond);
123
i = pthread_mutex_unlock (&thread2_tid_mutex);
126
rwatch_store = thread2_rwatch;
128
/* Be sure the "T (tracing stop)" test can proceed for both threads. */
129
timed_mutex_lock (&terminate_mutex);
130
i = pthread_mutex_unlock (&terminate_mutex);
137
proc_string (const char *filename, const char *line)
140
static char buf[LINE_MAX];
141
size_t line_len = strlen (line);
143
f = fopen (filename, "r");
146
fprintf (stderr, "fopen (\"%s\") for \"%s\": %s\n", filename, line,
150
while (errno = 0, fgets (buf, sizeof (buf), f))
154
s = strchr (buf, '\n');
158
if (strncmp (buf, line, line_len) != 0)
163
fprintf (stderr, "fclose (\"%s\") for \"%s\": %s\n", filename, line,
168
return &buf[line_len];
172
fprintf (stderr, "fgets (\"%s\": %s\n", filename, strerror (errno));
175
fprintf (stderr, "\"%s\": No line \"%s\" found.\n", filename, line);
180
proc_ulong (const char *filename, const char *line)
182
const char *s = proc_string (filename, line);
187
retval = strtol (s, &end, 10);
188
if (retval < 0 || retval >= LONG_MAX || (end && *end))
190
fprintf (stderr, "\"%s\":\"%s\": %ld, %s\n", filename, line, retval,
198
state_wait (pid_t process, const char *wanted)
202
struct timespec start, now;
205
i = asprintf (&filename, "/proc/%lu/status", (unsigned long) process);
208
i = clock_gettime (CLOCK_MONOTONIC, &start);
213
state = proc_string (filename, "State:\t");
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, thread1_func, NULL);
278
i = pthread_create (&thread2, NULL, thread2_func, NULL);
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 watchpoints 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 watchpoints.\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 */
359
/* Just prevent compiler `warning: unusedX_rwatch defined but not used'. */