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2894 svoboda 1
/*
2
 * Copyright (c) 2008 Jiri Svoboda
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
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
2801 svoboda 29
/** @addtogroup generic
30
 * @{
31
 */
32
 
33
/**
34
 * @file
3471 svoboda 35
 * @brief   Udebug hooks and data structure management.
3031 svoboda 36
 *
3471 svoboda 37
 * Udebug is an interface that makes userspace debuggers possible.
2801 svoboda 38
 */
39
 
40
#include <synch/waitq.h>
3471 svoboda 41
#include <debug.h>
2813 svoboda 42
#include <udebug/udebug.h>
2870 svoboda 43
#include <errno.h>
2801 svoboda 44
#include <arch.h>
45
 
3026 svoboda 46
 
3471 svoboda 47
/** Initialize udebug part of task structure.
48
 *
49
 * Called as part of task structure initialization.
50
 * @param ut    Pointer to the structure to initialize.
51
 */
3014 svoboda 52
void udebug_task_init(udebug_task_t *ut)
53
{
3426 svoboda 54
    mutex_initialize(&ut->lock, MUTEX_PASSIVE);
3014 svoboda 55
    ut->dt_state = UDEBUG_TS_INACTIVE;
56
    ut->begin_call = NULL;
57
    ut->not_stoppable_count = 0;
58
    ut->evmask = 0;
59
}
60
 
3471 svoboda 61
/** Initialize udebug part of thread structure.
62
 *
63
 * Called as part of thread structure initialization.
64
 * @param ut    Pointer to the structure to initialize.
65
 */
3018 svoboda 66
void udebug_thread_initialize(udebug_thread_t *ut)
67
{
3426 svoboda 68
    mutex_initialize(&ut->lock, MUTEX_PASSIVE);
3018 svoboda 69
    waitq_initialize(&ut->go_wq);
3026 svoboda 70
 
3018 svoboda 71
    ut->go_call = NULL;
72
    ut->uspace_state = NULL;
3606 svoboda 73
    ut->go = false;
3018 svoboda 74
    ut->stoppable = true;
3684 svoboda 75
    ut->active = false;
3018 svoboda 76
    ut->cur_event = 0; /* none */
77
}
78
 
3471 svoboda 79
/** Wait for a GO message.
80
 *
81
 * When a debugging event occurs in a thread or the thread is stopped,
82
 * this function is called to block the thread until a GO message
83
 * is received.
84
 *
85
 * @param wq    The wait queue used by the thread to wait for GO messages.
86
 */
2917 svoboda 87
static void udebug_wait_for_go(waitq_t *wq)
88
{
89
    int rc;
90
    ipl_t ipl;
91
 
92
    ipl = waitq_sleep_prepare(wq);
93
 
94
    wq->missed_wakeups = 0; /* Enforce blocking. */
95
    rc = waitq_sleep_timeout_unsafe(wq, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
96
 
97
    waitq_sleep_finish(wq, rc, ipl);
98
}
99
 
3030 svoboda 100
/** Do a preliminary check that a debugging session is in progress.
101
 *
3471 svoboda 102
 * This only requires the THREAD->udebug.lock mutex (and not TASK->udebug.lock
103
 * mutex). For an undebugged task, this will never block (while there could be
104
 * collisions by different threads on the TASK mutex), thus improving SMP
105
 * perormance for undebugged tasks.
106
 *
107
 * @return  True if the thread was in a debugging session when the function
108
 *      checked, false otherwise.
3030 svoboda 109
 */
110
static bool udebug_thread_precheck(void)
111
{
112
    bool res;
113
 
114
    mutex_lock(&THREAD->udebug.lock);
3684 svoboda 115
    res = THREAD->udebug.active;
3030 svoboda 116
    mutex_unlock(&THREAD->udebug.lock);
117
 
118
    return res;
119
}
120
 
3471 svoboda 121
/** Start of stoppable section.
122
 *
123
 * A stoppable section is a section of code where if the thread can be stoped. In other words,
124
 * if a STOP operation is issued, the thread is guaranteed not to execute
125
 * any userspace instructions until the thread is resumed.
126
 *
127
 * Having stoppable sections is better than having stopping points, since
128
 * a thread can be stopped even when it is blocked indefinitely in a system
129
 * call (whereas it would not reach any stopping point).
130
 */
2804 svoboda 131
void udebug_stoppable_begin(void)
2801 svoboda 132
{
2804 svoboda 133
    int nsc;
2898 svoboda 134
    call_t *db_call, *go_call;
2804 svoboda 135
 
2902 svoboda 136
    ASSERT(THREAD);
137
    ASSERT(TASK);
138
 
3030 svoboda 139
    /* Early check for undebugged tasks */
140
    if (!udebug_thread_precheck()) {
141
        return;
142
    }
143
 
3016 svoboda 144
    mutex_lock(&TASK->udebug.lock);
2804 svoboda 145
 
3014 svoboda 146
    nsc = --TASK->udebug.not_stoppable_count;
2804 svoboda 147
 
3032 svoboda 148
    /* Lock order OK, THREAD->udebug.lock is after TASK->udebug.lock */
149
    mutex_lock(&THREAD->udebug.lock);
150
    ASSERT(THREAD->udebug.stoppable == false);
151
    THREAD->udebug.stoppable = true;
2804 svoboda 152
 
3014 svoboda 153
    if (TASK->udebug.dt_state == UDEBUG_TS_BEGINNING && nsc == 0) {
2898 svoboda 154
        /*
155
         * This was the last non-stoppable thread. Reply to
156
         * DEBUG_BEGIN call.
157
         */
158
 
3014 svoboda 159
        db_call = TASK->udebug.begin_call;
2902 svoboda 160
        ASSERT(db_call);
161
 
3014 svoboda 162
        TASK->udebug.dt_state = UDEBUG_TS_ACTIVE;
163
        TASK->udebug.begin_call = NULL;
2804 svoboda 164
 
165
        IPC_SET_RETVAL(db_call->data, 0);
166
        ipc_answer(&TASK->answerbox, db_call);     
2898 svoboda 167
 
3014 svoboda 168
    } else if (TASK->udebug.dt_state == UDEBUG_TS_ACTIVE) {
2898 svoboda 169
        /*
170
         * Active debugging session
171
         */
172
 
3684 svoboda 173
        if (THREAD->udebug.active == true &&
3606 svoboda 174
            THREAD->udebug.go == false) {
2898 svoboda 175
            /*
176
             * Thread was requested to stop - answer go call
177
             */
178
 
179
            /* Make sure nobody takes this call away from us */
3018 svoboda 180
            go_call = THREAD->udebug.go_call;
181
            THREAD->udebug.go_call = NULL;
2902 svoboda 182
            ASSERT(go_call);
2898 svoboda 183
 
184
            IPC_SET_RETVAL(go_call->data, 0);
185
            IPC_SET_ARG1(go_call->data, UDEBUG_EVENT_STOP);
186
 
3018 svoboda 187
            THREAD->udebug.cur_event = UDEBUG_EVENT_STOP;
2898 svoboda 188
 
189
                ipc_answer(&TASK->answerbox, go_call);
190
        }
3032 svoboda 191
    }
2898 svoboda 192
 
3032 svoboda 193
    mutex_unlock(&THREAD->udebug.lock);
194
        mutex_unlock(&TASK->udebug.lock);
2804 svoboda 195
}
196
 
3471 svoboda 197
/** End of a stoppable section.
198
 *
199
 * This is the point where the thread will block if it is stopped.
200
 * (As, by definition, a stopped thread must not leave its stoppable section).
201
 */
2804 svoboda 202
void udebug_stoppable_end(void)
203
{
3030 svoboda 204
    /* Early check for undebugged tasks */
205
    if (!udebug_thread_precheck()) {
206
        return;
207
    }
208
 
2804 svoboda 209
restart:
3016 svoboda 210
    mutex_lock(&TASK->udebug.lock);
3026 svoboda 211
    mutex_lock(&THREAD->udebug.lock);
2898 svoboda 212
 
3684 svoboda 213
    if (THREAD->udebug.active && THREAD->udebug.go == false) {
3014 svoboda 214
        TASK->udebug.begin_call = NULL;
3026 svoboda 215
        mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 216
        mutex_unlock(&TASK->udebug.lock);
2823 svoboda 217
 
3018 svoboda 218
        udebug_wait_for_go(&THREAD->udebug.go_wq);
2917 svoboda 219
 
2804 svoboda 220
        goto restart;
3606 svoboda 221
        /* Must try again - have to lose stoppability atomically. */
2804 svoboda 222
    } else {
3014 svoboda 223
        ++TASK->udebug.not_stoppable_count;
3026 svoboda 224
        ASSERT(THREAD->udebug.stoppable == true);
3018 svoboda 225
        THREAD->udebug.stoppable = false;
2898 svoboda 226
 
3026 svoboda 227
        mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 228
        mutex_unlock(&TASK->udebug.lock);
2801 svoboda 229
    }
230
}
231
 
3015 svoboda 232
/** Upon being scheduled to run, check if the current thread should stop.
233
 *
3611 svoboda 234
 * This function is called from clock().
3015 svoboda 235
 */
236
void udebug_before_thread_runs(void)
237
{
3611 svoboda 238
    /* Check if we are supposed to stop. */
3015 svoboda 239
    udebug_stoppable_begin();
240
    udebug_stoppable_end();
241
}
242
 
3471 svoboda 243
/** Syscall event hook.
244
 *
245
 * Must be called before and after servicing a system call. This generates
246
 * a SYSCALL_B or SYSCALL_E event, depending on the value of @a end_variant.
247
 */
2805 svoboda 248
void udebug_syscall_event(unative_t a1, unative_t a2, unative_t a3,
2901 svoboda 249
    unative_t a4, unative_t a5, unative_t a6, unative_t id, unative_t rc,
250
    bool end_variant)
2801 svoboda 251
{
2805 svoboda 252
    call_t *call;
2901 svoboda 253
    udebug_event_t etype;
2805 svoboda 254
 
2901 svoboda 255
    etype = end_variant ? UDEBUG_EVENT_SYSCALL_E : UDEBUG_EVENT_SYSCALL_B;
256
 
3030 svoboda 257
    /* Early check for undebugged tasks */
258
    if (!udebug_thread_precheck()) {
259
        return;
260
    }
261
 
3016 svoboda 262
    mutex_lock(&TASK->udebug.lock);
3026 svoboda 263
    mutex_lock(&THREAD->udebug.lock);
3016 svoboda 264
 
3606 svoboda 265
    /* Must only generate events when in debugging session and is go. */
3684 svoboda 266
    if (THREAD->udebug.active != true || THREAD->udebug.go == false ||
3014 svoboda 267
        (TASK->udebug.evmask & UDEBUG_EVMASK(etype)) == 0) {
3026 svoboda 268
        mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 269
        mutex_unlock(&TASK->udebug.lock);
2867 svoboda 270
        return;
271
    }
2804 svoboda 272
 
3424 svoboda 273
    //printf("udebug_syscall_event\n");
3018 svoboda 274
    call = THREAD->udebug.go_call;
275
    THREAD->udebug.go_call = NULL;
3016 svoboda 276
 
2867 svoboda 277
    IPC_SET_RETVAL(call->data, 0);
2901 svoboda 278
    IPC_SET_ARG1(call->data, etype);
2867 svoboda 279
    IPC_SET_ARG2(call->data, id);
280
    IPC_SET_ARG3(call->data, rc);
3424 svoboda 281
    //printf("udebug_syscall_event/ipc_answer\n");
2805 svoboda 282
 
3018 svoboda 283
    THREAD->udebug.syscall_args[0] = a1;
284
    THREAD->udebug.syscall_args[1] = a2;
285
    THREAD->udebug.syscall_args[2] = a3;
286
    THREAD->udebug.syscall_args[3] = a4;
287
    THREAD->udebug.syscall_args[4] = a5;
288
    THREAD->udebug.syscall_args[5] = a6;
2866 svoboda 289
 
2867 svoboda 290
    /*
3606 svoboda 291
     * Make sure udebug.go is false when going to sleep
2867 svoboda 292
     * in case we get woken up by DEBUG_END. (At which
293
     * point it must be back to the initial true value).
294
     */
3606 svoboda 295
    THREAD->udebug.go = false;
3018 svoboda 296
    THREAD->udebug.cur_event = etype;
2867 svoboda 297
 
3016 svoboda 298
    ipc_answer(&TASK->answerbox, call);
299
 
3032 svoboda 300
    mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 301
    mutex_unlock(&TASK->udebug.lock);
302
 
3018 svoboda 303
    udebug_wait_for_go(&THREAD->udebug.go_wq);
2867 svoboda 304
}
305
 
3623 svoboda 306
/** Thread-creation event hook combined with attaching the thread.
3471 svoboda 307
 *
308
 * Must be called when a new userspace thread is created in the debugged
3623 svoboda 309
 * task. Generates a THREAD_B event. Also attaches the thread @a t
310
 * to the task @a ta.
3471 svoboda 311
 *
3623 svoboda 312
 * This is necessary to avoid a race condition where the BEGIN and THREAD_READ
313
 * requests would be handled inbetween attaching the thread and checking it
314
 * for being in a debugging session to send the THREAD_B event. We could then
315
 * either miss threads or get some threads both in the thread list
316
 * and get a THREAD_B event for them.
317
 *
3471 svoboda 318
 * @param t Structure of the thread being created. Not locked, as the
319
 *      thread is not executing yet.
3623 svoboda 320
 * @param ta    Task to which the thread should be attached.
3471 svoboda 321
 */
3623 svoboda 322
void udebug_thread_b_event_attach(struct thread *t, struct task *ta)
2867 svoboda 323
{
324
    call_t *call;
325
 
3016 svoboda 326
    mutex_lock(&TASK->udebug.lock);
3026 svoboda 327
    mutex_lock(&THREAD->udebug.lock);
3016 svoboda 328
 
3623 svoboda 329
    thread_attach(t, ta);
330
 
3471 svoboda 331
    LOG("udebug_thread_b_event\n");
332
    LOG("- check state\n");
2867 svoboda 333
 
334
    /* Must only generate events when in debugging session */
3684 svoboda 335
    if (THREAD->udebug.active != true) {
336
        LOG("- udebug.active: %s, udebug.go: %s\n",
337
            THREAD->udebug.active ? "yes(+)" : "no(-)",
3606 svoboda 338
            THREAD->udebug.go ? "yes(-)" : "no(+)");
3026 svoboda 339
        mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 340
        mutex_unlock(&TASK->udebug.lock);
2867 svoboda 341
        return;
2801 svoboda 342
    }
2867 svoboda 343
 
3471 svoboda 344
    LOG("- trigger event\n");
2867 svoboda 345
 
3018 svoboda 346
    call = THREAD->udebug.go_call;
347
    THREAD->udebug.go_call = NULL;
2867 svoboda 348
    IPC_SET_RETVAL(call->data, 0);
2903 svoboda 349
    IPC_SET_ARG1(call->data, UDEBUG_EVENT_THREAD_B);
2867 svoboda 350
    IPC_SET_ARG2(call->data, (unative_t)t);
351
 
352
    /*
3606 svoboda 353
     * Make sure udebug.go is false when going to sleep
2867 svoboda 354
     * in case we get woken up by DEBUG_END. (At which
355
     * point it must be back to the initial true value).
356
     */
3606 svoboda 357
    THREAD->udebug.go = false;
3018 svoboda 358
    THREAD->udebug.cur_event = UDEBUG_EVENT_THREAD_B;
2867 svoboda 359
 
3016 svoboda 360
    ipc_answer(&TASK->answerbox, call);
2867 svoboda 361
 
3032 svoboda 362
    mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 363
    mutex_unlock(&TASK->udebug.lock);
364
 
3471 svoboda 365
    LOG("- sleep\n");
3018 svoboda 366
    udebug_wait_for_go(&THREAD->udebug.go_wq);
2801 svoboda 367
}
368
 
3471 svoboda 369
/** Thread-termination event hook.
370
 *
371
 * Must be called when the current thread is terminating.
372
 * Generates a THREAD_E event.
373
 */
2903 svoboda 374
void udebug_thread_e_event(void)
375
{
376
    call_t *call;
377
 
3016 svoboda 378
    mutex_lock(&TASK->udebug.lock);
3026 svoboda 379
    mutex_lock(&THREAD->udebug.lock);
3016 svoboda 380
 
3471 svoboda 381
    LOG("udebug_thread_e_event\n");
382
    LOG("- check state\n");
2903 svoboda 383
 
3606 svoboda 384
    /* Must only generate events when in debugging session. */
3684 svoboda 385
    if (THREAD->udebug.active != true) {
386
/*      printf("- udebug.active: %s, udebug.go: %s\n",
387
            THREAD->udebug.active ? "yes(+)" : "no(-)",
3606 svoboda 388
            THREAD->udebug.go ? "yes(-)" : "no(+)");*/
3026 svoboda 389
        mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 390
        mutex_unlock(&TASK->udebug.lock);
2903 svoboda 391
        return;
392
    }
393
 
3471 svoboda 394
    LOG("- trigger event\n");
2903 svoboda 395
 
3018 svoboda 396
    call = THREAD->udebug.go_call;
397
    THREAD->udebug.go_call = NULL;
2903 svoboda 398
    IPC_SET_RETVAL(call->data, 0);
399
    IPC_SET_ARG1(call->data, UDEBUG_EVENT_THREAD_E);
400
 
3606 svoboda 401
    /* Prevent any further debug activity in thread. */
3684 svoboda 402
    THREAD->udebug.active = false;
3018 svoboda 403
    THREAD->udebug.cur_event = 0;       /* none */
3606 svoboda 404
    THREAD->udebug.go = false;  /* set to initial value */
3016 svoboda 405
 
406
    ipc_answer(&TASK->answerbox, call);
2903 svoboda 407
 
3032 svoboda 408
    mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 409
    mutex_unlock(&TASK->udebug.lock);
2903 svoboda 410
 
3606 svoboda 411
    /*
412
     * This event does not sleep - debugging has finished
413
     * in this thread.
414
     */
2903 svoboda 415
}
416
 
2921 svoboda 417
static void breakpoint_trap_event(uintptr_t addr, udebug_event_t etype)
2918 svoboda 418
{
419
    call_t *call;
2903 svoboda 420
 
3016 svoboda 421
    mutex_lock(&TASK->udebug.lock);
3026 svoboda 422
    mutex_lock(&THREAD->udebug.lock);
3016 svoboda 423
 
3606 svoboda 424
    /* Must only generate events when in debugging session and have go. */
3684 svoboda 425
    if (THREAD->udebug.active != true || THREAD->udebug.go == false) {
3026 svoboda 426
        mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 427
        mutex_unlock(&TASK->udebug.lock);
2918 svoboda 428
        return;
429
    }
430
 
3030 svoboda 431
    /* Verify that the event is enabled */
432
    if ((TASK->udebug.evmask & UDEBUG_EVMASK(etype)) == 0) {
433
        mutex_unlock(&THREAD->udebug.lock);
434
        mutex_unlock(&TASK->udebug.lock);
435
        return;
436
    }
437
 
3611 svoboda 438
    LOG("udebug_breakpoint/trap_event\n");
3018 svoboda 439
    call = THREAD->udebug.go_call;
440
    THREAD->udebug.go_call = NULL;
3016 svoboda 441
 
2918 svoboda 442
    IPC_SET_RETVAL(call->data, 0);
443
    IPC_SET_ARG1(call->data, etype);
444
    IPC_SET_ARG2(call->data, addr);
445
 
446
    /*
3606 svoboda 447
     * Make sure udebug.go is false when going to sleep
2918 svoboda 448
     * in case we get woken up by DEBUG_END. (At which
449
     * point it must be back to the initial true value).
450
     */
3606 svoboda 451
    THREAD->udebug.go = false;
3018 svoboda 452
    THREAD->udebug.cur_event = etype;
3026 svoboda 453
 
3611 svoboda 454
    LOG("- send answer\n");
3032 svoboda 455
    ipc_answer(&TASK->answerbox, call);
2918 svoboda 456
 
3032 svoboda 457
    mutex_unlock(&THREAD->udebug.lock);
3016 svoboda 458
    mutex_unlock(&TASK->udebug.lock);
2918 svoboda 459
 
3018 svoboda 460
    udebug_wait_for_go(&THREAD->udebug.go_wq);
2918 svoboda 461
}
462
 
2921 svoboda 463
void udebug_breakpoint_event(uintptr_t addr)
464
{
465
    breakpoint_trap_event(addr, UDEBUG_EVENT_BREAKPOINT);
466
}
2918 svoboda 467
 
2921 svoboda 468
void udebug_trap_event(uintptr_t addr)
469
{
470
    breakpoint_trap_event(addr, UDEBUG_EVENT_TRAP);
471
}
472
 
2870 svoboda 473
/**
474
 * Terminate task debugging session.
475
 *
3471 svoboda 476
 * Gracefully terminates the debugging session for a task. If the debugger
477
 * is still waiting for events on some threads, it will receive a
478
 * FINISHED event for each of them.
479
 *
480
 * @param ta    Task structure. ta->udebug.lock must be already locked.
481
 * @return  Zero on success or negative error code.
2870 svoboda 482
 */
483
int udebug_task_cleanup(struct task *ta)
484
{
485
    thread_t *t;
486
    link_t *cur;
487
    int flags;
3016 svoboda 488
    ipl_t ipl;
2867 svoboda 489
 
3471 svoboda 490
    LOG("udebug_task_cleanup()\n");
491
    LOG("task %" PRIu64 "\n", ta->taskid);
2870 svoboda 492
 
3032 svoboda 493
    if (ta->udebug.dt_state != UDEBUG_TS_BEGINNING &&
3014 svoboda 494
        ta->udebug.dt_state != UDEBUG_TS_ACTIVE) {
3471 svoboda 495
        LOG("udebug_task_cleanup(): task not being debugged\n");
2870 svoboda 496
        return EINVAL;
497
    }
498
 
499
    /* Finish debugging of all userspace threads */
500
    for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
501
        t = list_get_instance(cur, thread_t, th_link);
502
 
3026 svoboda 503
        mutex_lock(&t->udebug.lock);
504
 
3016 svoboda 505
        ipl = interrupts_disable();
2870 svoboda 506
        spinlock_lock(&t->lock);
507
 
508
        flags = t->flags;
509
 
510
        spinlock_unlock(&t->lock);
3026 svoboda 511
        interrupts_restore(ipl);
2870 svoboda 512
 
3606 svoboda 513
        /* Only process userspace threads. */
2870 svoboda 514
        if ((flags & THREAD_FLAG_USPACE) != 0) {
3606 svoboda 515
            /* Prevent any further debug activity in thread. */
3684 svoboda 516
            t->udebug.active = false;
3018 svoboda 517
            t->udebug.cur_event = 0;    /* none */
2870 svoboda 518
 
3606 svoboda 519
            /* Is the thread still go? */
520
            if (t->udebug.go == true) {
2870 svoboda 521
                /*
3684 svoboda 522
                * Yes, so clear go. As active == false,
2870 svoboda 523
                 * this doesn't affect anything.
524
                 */
3606 svoboda 525
                t->udebug.go = false;  
2870 svoboda 526
 
527
                /* Answer GO call */
3471 svoboda 528
                LOG("answer GO call with EVENT_FINISHED\n");
3018 svoboda 529
                IPC_SET_RETVAL(t->udebug.go_call->data, 0);
3471 svoboda 530
                IPC_SET_ARG1(t->udebug.go_call->data,
531
                    UDEBUG_EVENT_FINISHED);
3026 svoboda 532
 
3018 svoboda 533
                ipc_answer(&ta->answerbox, t->udebug.go_call);
534
                t->udebug.go_call = NULL;
2870 svoboda 535
            } else {
536
                /*
537
                 * Debug_stop is already at initial value.
538
                 * Yet this means the thread needs waking up.
539
                 */
540
 
541
                /*
542
                 * t's lock must not be held when calling
543
                 * waitq_wakeup.
544
                 */
3018 svoboda 545
                waitq_wakeup(&t->udebug.go_wq, WAKEUP_FIRST);
2870 svoboda 546
            }
547
        }
3026 svoboda 548
        mutex_unlock(&t->udebug.lock);
2870 svoboda 549
    }
550
 
3014 svoboda 551
    ta->udebug.dt_state = UDEBUG_TS_INACTIVE;
552
    ta->udebug.debugger = NULL;
2870 svoboda 553
 
554
    return 0;
555
}
556
 
557
 
2801 svoboda 558
/** @}
559
 */