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1 jermar 1
/*
2
 * Copyright (C) 2001-2004 Jakub Jermar
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
 
1702 cejka 29
 /** @addtogroup genericproc
30
 * @{
31
 */
32
 
1248 jermar 33
/**
1702 cejka 34
 * @file
1248 jermar 35
 * @brief   Task management.
36
 */
37
 
973 palkovsky 38
#include <main/uinit.h>
1 jermar 39
#include <proc/thread.h>
40
#include <proc/task.h>
1078 jermar 41
#include <proc/uarg.h>
703 jermar 42
#include <mm/as.h>
814 palkovsky 43
#include <mm/slab.h>
1 jermar 44
#include <synch/spinlock.h>
45
#include <arch.h>
46
#include <panic.h>
1159 jermar 47
#include <adt/btree.h>
788 jermar 48
#include <adt/list.h>
955 palkovsky 49
#include <ipc/ipc.h>
1174 jermar 50
#include <security/cap.h>
955 palkovsky 51
#include <memstr.h>
1060 palkovsky 52
#include <print.h>
973 palkovsky 53
#include <elf.h>
1579 jermar 54
#include <errno.h>
1288 jermar 55
#include <syscall/copy.h>
1597 palkovsky 56
#include <console/klog.h>
973 palkovsky 57
 
1170 vana 58
#ifndef LOADED_PROG_STACK_PAGES_NO
59
#define LOADED_PROG_STACK_PAGES_NO 1
60
#endif
1168 vana 61
 
1636 jermar 62
/** Spinlock protecting the tasks_btree B+tree. */
623 jermar 63
SPINLOCK_INITIALIZE(tasks_lock);
1636 jermar 64
 
65
/** B+tree of active tasks.
66
 *
67
 * The task is guaranteed to exist after it was found in the tasks_btree as long as:
68
 * @li the tasks_lock is held,
69
 * @li the task's lock is held when task's lock is acquired before releasing tasks_lock or
70
 * @li the task's refcount is grater than 0
71
 *
72
 */
1159 jermar 73
btree_t tasks_btree;
1636 jermar 74
 
1005 palkovsky 75
static task_id_t task_counter = 0;
1 jermar 76
 
1585 jermar 77
static void ktaskclnp(void *arg);
1661 jermar 78
static void ktaskgc(void *arg);
1579 jermar 79
 
107 decky 80
/** Initialize tasks
81
 *
82
 * Initialize kernel tasks support.
83
 *
84
 */
1 jermar 85
void task_init(void)
86
{
15 jermar 87
    TASK = NULL;
1159 jermar 88
    btree_create(&tasks_btree);
1 jermar 89
}
90
 
107 decky 91
 
92
/** Create new task
93
 *
94
 * Create new task with no threads.
95
 *
703 jermar 96
 * @param as Task's address space.
1062 jermar 97
 * @param name Symbolic name.
107 decky 98
 *
973 palkovsky 99
 * @return New task's structure
107 decky 100
 *
101
 */
1062 jermar 102
task_t *task_create(as_t *as, char *name)
1 jermar 103
{
413 jermar 104
    ipl_t ipl;
1 jermar 105
    task_t *ta;
1040 palkovsky 106
    int i;
1 jermar 107
 
822 palkovsky 108
    ta = (task_t *) malloc(sizeof(task_t), 0);
109
 
1185 jermar 110
    task_create_arch(ta);
111
 
822 palkovsky 112
    spinlock_initialize(&ta->lock, "task_ta_lock");
113
    list_initialize(&ta->th_head);
114
    ta->as = as;
1062 jermar 115
    ta->name = name;
1585 jermar 116
    ta->main_thread = NULL;
1579 jermar 117
    ta->refcount = 0;
118
 
1174 jermar 119
    ta->capabilities = 0;
1579 jermar 120
    ta->accept_new_threads = true;
1040 palkovsky 121
 
955 palkovsky 122
    ipc_answerbox_init(&ta->answerbox);
1040 palkovsky 123
    for (i=0; i < IPC_MAX_PHONES;i++)
124
        ipc_phone_init(&ta->phones[i]);
965 palkovsky 125
    if (ipc_phone_0)
1040 palkovsky 126
        ipc_phone_connect(&ta->phones[0], ipc_phone_0);
998 palkovsky 127
    atomic_set(&ta->active_calls, 0);
1460 jermar 128
 
129
    mutex_initialize(&ta->futexes_lock);
130
    btree_create(&ta->futexes);
822 palkovsky 131
 
132
    ipl = interrupts_disable();
1468 jermar 133
 
134
    /*
135
     * Increment address space reference count.
136
     * TODO: Reconsider the locking scheme.
137
     */
138
    mutex_lock(&as->lock);
139
    as->refcount++;
140
    mutex_unlock(&as->lock);
141
 
822 palkovsky 142
    spinlock_lock(&tasks_lock);
1005 palkovsky 143
 
144
    ta->taskid = ++task_counter;
1177 jermar 145
    btree_insert(&tasks_btree, (btree_key_t) ta->taskid, (void *) ta, NULL);
1005 palkovsky 146
 
822 palkovsky 147
    spinlock_unlock(&tasks_lock);
148
    interrupts_restore(ipl);
149
 
1 jermar 150
    return ta;
151
}
152
 
1579 jermar 153
/** Destroy task.
154
 *
155
 * @param t Task to be destroyed.
156
 */
157
void task_destroy(task_t *t)
158
{
1587 jermar 159
    task_destroy_arch(t);
160
    btree_destroy(&t->futexes);
161
 
162
    mutex_lock_active(&t->as->lock);
163
    if (--t->as->refcount == 0) {
164
        mutex_unlock(&t->as->lock);
165
        as_destroy(t->as);
166
        /*
167
         * t->as is destroyed.
168
         */
169
    } else {
170
        mutex_unlock(&t->as->lock);
171
    }
172
 
173
    free(t);
174
    TASK = NULL;
1579 jermar 175
}
176
 
973 palkovsky 177
/** Create new task with 1 thread and run it
178
 *
1248 jermar 179
 * @param program_addr Address of program executable image.
1062 jermar 180
 * @param name Program name.
181
 *
1229 jermar 182
 * @return Task of the running program or NULL on error.
973 palkovsky 183
 */
1062 jermar 184
task_t * task_run_program(void *program_addr, char *name)
973 palkovsky 185
{
186
    as_t *as;
187
    as_area_t *a;
188
    int rc;
1585 jermar 189
    thread_t *t1, *t2;
973 palkovsky 190
    task_t *task;
1078 jermar 191
    uspace_arg_t *kernel_uarg;
973 palkovsky 192
 
193
    as = as_create(0);
1115 jermar 194
    ASSERT(as);
973 palkovsky 195
 
1025 palkovsky 196
    rc = elf_load((elf_header_t *) program_addr, as);
973 palkovsky 197
    if (rc != EE_OK) {
1468 jermar 198
        as_destroy(as);
973 palkovsky 199
        return NULL;
200
    }
201
 
1078 jermar 202
    kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
203
    kernel_uarg->uspace_entry = (void *) ((elf_header_t *) program_addr)->e_entry;
204
    kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
205
    kernel_uarg->uspace_thread_function = NULL;
206
    kernel_uarg->uspace_thread_arg = NULL;
207
    kernel_uarg->uspace_uarg = NULL;
1066 jermar 208
 
1062 jermar 209
    task = task_create(as, name);
1115 jermar 210
    ASSERT(task);
211
 
973 palkovsky 212
    /*
213
     * Create the data as_area.
214
     */
1424 jermar 215
    a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
216
        LOADED_PROG_STACK_PAGES_NO*PAGE_SIZE,
1409 jermar 217
        USTACK_ADDRESS, AS_AREA_ATTR_NONE, &anon_backend, NULL);
1115 jermar 218
 
1585 jermar 219
    /*
220
     * Create the main thread.
221
     */
222
    t1 = thread_create(uinit, kernel_uarg, task, 0, "uinit");
223
    ASSERT(t1);
973 palkovsky 224
 
1585 jermar 225
    /*
226
     * Create killer thread for the new task.
227
     */
1661 jermar 228
    t2 = thread_create(ktaskgc, t1, task, 0, "ktaskgc");
1585 jermar 229
    ASSERT(t2);
230
    thread_ready(t2);
231
 
232
    thread_ready(t1);
233
 
973 palkovsky 234
    return task;
235
}
1060 palkovsky 236
 
1176 jermar 237
/** Syscall for reading task ID from userspace.
238
 *
1248 jermar 239
 * @param uspace_task_id Userspace address of 8-byte buffer where to store current task ID.
1176 jermar 240
 *
1288 jermar 241
 * @return 0 on success or an error code from @ref errno.h.
1176 jermar 242
 */
1227 jermar 243
__native sys_task_get_id(task_id_t *uspace_task_id)
1176 jermar 244
{
245
    /*
246
     * No need to acquire lock on TASK because taskid
247
     * remains constant for the lifespan of the task.
248
     */
1288 jermar 249
    return (__native) copy_to_uspace(uspace_task_id, &TASK->taskid, sizeof(TASK->taskid));
1176 jermar 250
}
251
 
1178 jermar 252
/** Find task structure corresponding to task ID.
253
 *
254
 * The tasks_lock must be already held by the caller of this function
255
 * and interrupts must be disabled.
256
 *
257
 * @param id Task ID.
258
 *
259
 * @return Task structure address or NULL if there is no such task ID.
260
 */
261
task_t *task_find_by_id(task_id_t id)
262
{
263
    btree_node_t *leaf;
264
 
265
    return (task_t *) btree_search(&tasks_btree, (btree_key_t) id, &leaf);
266
}
267
 
1579 jermar 268
/** Kill task.
269
 *
270
 * @param id ID of the task to be killed.
271
 *
272
 * @return 0 on success or an error code from errno.h
273
 */
274
int task_kill(task_id_t id)
275
{
276
    ipl_t ipl;
277
    task_t *ta;
278
    thread_t *t;
279
    link_t *cur;
1600 jermar 280
 
281
    if (id == 1)
282
        return EPERM;
1579 jermar 283
 
284
    ipl = interrupts_disable();
285
    spinlock_lock(&tasks_lock);
286
 
287
    if (!(ta = task_find_by_id(id))) {
288
        spinlock_unlock(&tasks_lock);
289
        interrupts_restore(ipl);
290
        return ENOENT;
291
    }
1588 jermar 292
 
1579 jermar 293
    spinlock_lock(&ta->lock);
294
    ta->refcount++;
295
    spinlock_unlock(&ta->lock);
1587 jermar 296
 
1588 jermar 297
    btree_remove(&tasks_btree, ta->taskid, NULL);
1587 jermar 298
    spinlock_unlock(&tasks_lock);
1579 jermar 299
 
1580 jermar 300
    t = thread_create(ktaskclnp, NULL, ta, 0, "ktaskclnp");
1579 jermar 301
 
302
    spinlock_lock(&ta->lock);
1580 jermar 303
    ta->accept_new_threads = false;
1579 jermar 304
    ta->refcount--;
1585 jermar 305
 
306
    /*
1687 jermar 307
     * Interrupt all threads except ktaskclnp.
1585 jermar 308
     */
1579 jermar 309
    for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
310
        thread_t *thr;
311
        bool  sleeping = false;
312
 
313
        thr = list_get_instance(cur, thread_t, th_link);
314
        if (thr == t)
315
            continue;
316
 
317
        spinlock_lock(&thr->lock);
318
        thr->interrupted = true;
319
        if (thr->state == Sleeping)
320
            sleeping = true;
321
        spinlock_unlock(&thr->lock);
322
 
323
        if (sleeping)
324
            waitq_interrupt_sleep(thr);
325
    }
326
 
1580 jermar 327
    spinlock_unlock(&ta->lock);
328
    interrupts_restore(ipl);
1579 jermar 329
 
1580 jermar 330
    if (t)
331
        thread_ready(t);
332
 
1579 jermar 333
    return 0;
334
}
335
 
1060 palkovsky 336
/** Print task list */
337
void task_print_list(void)
338
{
339
    link_t *cur;
340
    ipl_t ipl;
341
 
342
    /* Messing with thread structures, avoid deadlock */
343
    ipl = interrupts_disable();
344
    spinlock_lock(&tasks_lock);
345
 
1159 jermar 346
    for (cur = tasks_btree.leaf_head.next; cur != &tasks_btree.leaf_head; cur = cur->next) {
347
        btree_node_t *node;
348
        int i;
349
 
350
        node = list_get_instance(cur, btree_node_t, leaf_link);
351
        for (i = 0; i < node->keys; i++) {
352
            task_t *t;
353
            int j;
354
 
355
            t = (task_t *) node->value[i];
356
 
357
            spinlock_lock(&t->lock);
1573 palkovsky 358
            printf("%s(%lld): address=%#zX, as=%#zX, ActiveCalls: %zd",
359
                t->name, t->taskid, t, t->as, atomic_get(&t->active_calls));
1159 jermar 360
            for (j=0; j < IPC_MAX_PHONES; j++) {
361
                if (t->phones[j].callee)
1196 cejka 362
                    printf(" Ph(%zd): %#zX ", j, t->phones[j].callee);
1159 jermar 363
            }
364
            printf("\n");
365
            spinlock_unlock(&t->lock);
1060 palkovsky 366
        }
367
    }
368
 
369
    spinlock_unlock(&tasks_lock);
370
    interrupts_restore(ipl);
371
}
1579 jermar 372
 
1585 jermar 373
/** Kernel thread used to cleanup the task after it is killed. */
1580 jermar 374
void ktaskclnp(void *arg)
1579 jermar 375
{
1580 jermar 376
    ipl_t ipl;
1585 jermar 377
    thread_t *t = NULL, *main_thread;
1580 jermar 378
    link_t *cur;
1661 jermar 379
    bool again;
1580 jermar 380
 
381
    thread_detach(THREAD);
382
 
383
loop:
384
    ipl = interrupts_disable();
385
    spinlock_lock(&TASK->lock);
386
 
1585 jermar 387
    main_thread = TASK->main_thread;
388
 
1579 jermar 389
    /*
1580 jermar 390
     * Find a thread to join.
391
     */
1661 jermar 392
    again = false;
1580 jermar 393
    for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
394
        t = list_get_instance(cur, thread_t, th_link);
1661 jermar 395
 
396
        spinlock_lock(&t->lock);
397
        if (t == THREAD) {
398
            spinlock_unlock(&t->lock);
1580 jermar 399
            continue;
1661 jermar 400
        } else if (t == main_thread) {
401
            spinlock_unlock(&t->lock);
1585 jermar 402
            continue;
1661 jermar 403
        } else if (t->join_type != None) {
404
            spinlock_unlock(&t->lock);
405
            again = true;
406
            continue;
407
        } else {
408
            t->join_type = TaskClnp;
409
            spinlock_unlock(&t->lock);
410
            again = false;
1580 jermar 411
            break;
1661 jermar 412
        }
1580 jermar 413
    }
414
 
415
    spinlock_unlock(&TASK->lock);
416
    interrupts_restore(ipl);
417
 
1661 jermar 418
    if (again) {
419
        /*
420
         * Other cleanup (e.g. ktaskgc) is in progress.
421
         */
422
        scheduler();
423
        goto loop;
424
    }
425
 
1580 jermar 426
    if (t != THREAD) {
1661 jermar 427
        ASSERT(t != main_thread);   /* uninit is joined and detached in ktaskgc */
1580 jermar 428
        thread_join(t);
429
        thread_detach(t);
1585 jermar 430
        goto loop;  /* go for another thread */
1580 jermar 431
    }
432
 
433
    /*
434
     * Now there are no other threads in this task
435
     * and no new threads can be created.
436
     */
437
 
1583 jermar 438
    ipc_cleanup();
439
    futex_cleanup();
1597 palkovsky 440
    klog_printf("Cleanup of task %lld completed.", TASK->taskid);
1579 jermar 441
}
1585 jermar 442
 
1684 jermar 443
/** Kernel thread used to kill the userspace task when its main thread exits.
1585 jermar 444
 *
445
 * This thread waits until the main userspace thread (i.e. uninit) exits.
1661 jermar 446
 * When this happens, the task is killed. In the meantime, exited threads
447
 * are garbage collected.
1585 jermar 448
 *
449
 * @param arg Pointer to the thread structure of the task's main thread.
450
 */
1661 jermar 451
void ktaskgc(void *arg)
1585 jermar 452
{
453
    thread_t *t = (thread_t *) arg;
1661 jermar 454
loop:  
1585 jermar 455
    /*
456
     * Userspace threads cannot detach themselves,
457
     * therefore the thread pointer is guaranteed to be valid.
458
     */
1661 jermar 459
    if (thread_join_timeout(t, 1000000, SYNCH_FLAGS_NONE) == ESYNCH_TIMEOUT) {  /* sleep uninterruptibly here! */
460
        ipl_t ipl;
461
        link_t *cur;
462
        thread_t *thr = NULL;
463
 
464
        /*
465
         * The join timed out. Try to do some garbage collection of Undead threads.
466
         */
467
more_gc:       
468
        ipl = interrupts_disable();
469
        spinlock_lock(&TASK->lock);
470
 
471
        for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
472
            thr = list_get_instance(cur, thread_t, th_link);
473
            spinlock_lock(&thr->lock);
1687 jermar 474
            if (thr != t && thr->state == Undead && thr->join_type == None) {
1661 jermar 475
                thr->join_type = TaskGC;
476
                spinlock_unlock(&thr->lock);
477
                break;
478
            }
479
            spinlock_unlock(&thr->lock);
480
            thr = NULL;
481
        }
482
        spinlock_unlock(&TASK->lock);
1676 jermar 483
        interrupts_restore(ipl);
1661 jermar 484
 
485
        if (thr) {
486
            thread_join(thr);
487
            thread_detach(thr);
488
            scheduler();
489
            goto more_gc;
490
        }
491
 
492
        goto loop;
493
    }
1585 jermar 494
    thread_detach(t);
495
    task_kill(TASK->taskid);
496
}
1702 cejka 497
 
498
 /** @}
499
 */
500