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