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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
 
1757 jermar 29
/** @addtogroup genericproc
1702 cejka 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
1880 jermar 70
 * @li the task's refcount is greater than 0
1636 jermar 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;
1839 decky 118
    ta->context = CONTEXT;
1579 jermar 119
 
1174 jermar 120
    ta->capabilities = 0;
1579 jermar 121
    ta->accept_new_threads = true;
1040 palkovsky 122
 
955 palkovsky 123
    ipc_answerbox_init(&ta->answerbox);
1839 decky 124
    for (i = 0; i < IPC_MAX_PHONES; i++)
1040 palkovsky 125
        ipc_phone_init(&ta->phones[i]);
1839 decky 126
    if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context, ta->context)))
1040 palkovsky 127
        ipc_phone_connect(&ta->phones[0], ipc_phone_0);
998 palkovsky 128
    atomic_set(&ta->active_calls, 0);
1460 jermar 129
 
130
    mutex_initialize(&ta->futexes_lock);
131
    btree_create(&ta->futexes);
822 palkovsky 132
 
133
    ipl = interrupts_disable();
1468 jermar 134
 
135
    /*
136
     * Increment address space reference count.
137
     * TODO: Reconsider the locking scheme.
138
     */
139
    mutex_lock(&as->lock);
140
    as->refcount++;
141
    mutex_unlock(&as->lock);
142
 
822 palkovsky 143
    spinlock_lock(&tasks_lock);
1005 palkovsky 144
 
145
    ta->taskid = ++task_counter;
1177 jermar 146
    btree_insert(&tasks_btree, (btree_key_t) ta->taskid, (void *) ta, NULL);
1005 palkovsky 147
 
822 palkovsky 148
    spinlock_unlock(&tasks_lock);
149
    interrupts_restore(ipl);
150
 
1 jermar 151
    return ta;
152
}
153
 
1579 jermar 154
/** Destroy task.
155
 *
156
 * @param t Task to be destroyed.
157
 */
158
void task_destroy(task_t *t)
159
{
1587 jermar 160
    task_destroy_arch(t);
161
    btree_destroy(&t->futexes);
162
 
163
    mutex_lock_active(&t->as->lock);
164
    if (--t->as->refcount == 0) {
165
        mutex_unlock(&t->as->lock);
166
        as_destroy(t->as);
167
        /*
168
         * t->as is destroyed.
169
         */
170
    } else {
171
        mutex_unlock(&t->as->lock);
172
    }
173
 
174
    free(t);
175
    TASK = NULL;
1579 jermar 176
}
177
 
973 palkovsky 178
/** Create new task with 1 thread and run it
179
 *
1248 jermar 180
 * @param program_addr Address of program executable image.
1062 jermar 181
 * @param name Program name.
182
 *
1229 jermar 183
 * @return Task of the running program or NULL on error.
973 palkovsky 184
 */
1062 jermar 185
task_t * task_run_program(void *program_addr, char *name)
973 palkovsky 186
{
187
    as_t *as;
188
    as_area_t *a;
189
    int rc;
1585 jermar 190
    thread_t *t1, *t2;
973 palkovsky 191
    task_t *task;
1078 jermar 192
    uspace_arg_t *kernel_uarg;
973 palkovsky 193
 
194
    as = as_create(0);
1115 jermar 195
    ASSERT(as);
973 palkovsky 196
 
1025 palkovsky 197
    rc = elf_load((elf_header_t *) program_addr, as);
973 palkovsky 198
    if (rc != EE_OK) {
1468 jermar 199
        as_destroy(as);
973 palkovsky 200
        return NULL;
201
    }
202
 
1078 jermar 203
    kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
204
    kernel_uarg->uspace_entry = (void *) ((elf_header_t *) program_addr)->e_entry;
205
    kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
206
    kernel_uarg->uspace_thread_function = NULL;
207
    kernel_uarg->uspace_thread_arg = NULL;
208
    kernel_uarg->uspace_uarg = NULL;
1066 jermar 209
 
1062 jermar 210
    task = task_create(as, name);
1115 jermar 211
    ASSERT(task);
212
 
973 palkovsky 213
    /*
214
     * Create the data as_area.
215
     */
1424 jermar 216
    a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
217
        LOADED_PROG_STACK_PAGES_NO*PAGE_SIZE,
1409 jermar 218
        USTACK_ADDRESS, AS_AREA_ATTR_NONE, &anon_backend, NULL);
1115 jermar 219
 
1585 jermar 220
    /*
221
     * Create the main thread.
222
     */
1864 jermar 223
    t1 = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE, "uinit");
1585 jermar 224
    ASSERT(t1);
973 palkovsky 225
 
1585 jermar 226
    /*
227
     * Create killer thread for the new task.
228
     */
1661 jermar 229
    t2 = thread_create(ktaskgc, t1, task, 0, "ktaskgc");
1585 jermar 230
    ASSERT(t2);
231
    thread_ready(t2);
232
 
233
    thread_ready(t1);
234
 
973 palkovsky 235
    return task;
236
}
1060 palkovsky 237
 
1176 jermar 238
/** Syscall for reading task ID from userspace.
239
 *
1248 jermar 240
 * @param uspace_task_id Userspace address of 8-byte buffer where to store current task ID.
1176 jermar 241
 *
1288 jermar 242
 * @return 0 on success or an error code from @ref errno.h.
1176 jermar 243
 */
1780 jermar 244
unative_t sys_task_get_id(task_id_t *uspace_task_id)
1176 jermar 245
{
246
    /*
247
     * No need to acquire lock on TASK because taskid
248
     * remains constant for the lifespan of the task.
249
     */
1780 jermar 250
    return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid, sizeof(TASK->taskid));
1176 jermar 251
}
252
 
1178 jermar 253
/** Find task structure corresponding to task ID.
254
 *
255
 * The tasks_lock must be already held by the caller of this function
256
 * and interrupts must be disabled.
257
 *
258
 * @param id Task ID.
259
 *
260
 * @return Task structure address or NULL if there is no such task ID.
261
 */
262
task_t *task_find_by_id(task_id_t id)
263
{
264
    btree_node_t *leaf;
265
 
266
    return (task_t *) btree_search(&tasks_btree, (btree_key_t) id, &leaf);
267
}
268
 
1579 jermar 269
/** Kill task.
270
 *
271
 * @param id ID of the task to be killed.
272
 *
273
 * @return 0 on success or an error code from errno.h
274
 */
275
int task_kill(task_id_t id)
276
{
277
    ipl_t ipl;
278
    task_t *ta;
279
    thread_t *t;
280
    link_t *cur;
1600 jermar 281
 
282
    if (id == 1)
283
        return EPERM;
1579 jermar 284
 
285
    ipl = interrupts_disable();
286
    spinlock_lock(&tasks_lock);
287
 
288
    if (!(ta = task_find_by_id(id))) {
289
        spinlock_unlock(&tasks_lock);
290
        interrupts_restore(ipl);
291
        return ENOENT;
292
    }
1588 jermar 293
 
1579 jermar 294
    spinlock_lock(&ta->lock);
295
    ta->refcount++;
296
    spinlock_unlock(&ta->lock);
1587 jermar 297
 
1588 jermar 298
    btree_remove(&tasks_btree, ta->taskid, NULL);
1587 jermar 299
    spinlock_unlock(&tasks_lock);
1579 jermar 300
 
1580 jermar 301
    t = thread_create(ktaskclnp, NULL, ta, 0, "ktaskclnp");
1579 jermar 302
 
303
    spinlock_lock(&ta->lock);
1580 jermar 304
    ta->accept_new_threads = false;
1579 jermar 305
    ta->refcount--;
1585 jermar 306
 
307
    /*
1687 jermar 308
     * Interrupt all threads except ktaskclnp.
1585 jermar 309
     */
1579 jermar 310
    for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
311
        thread_t *thr;
312
        bool  sleeping = false;
313
 
314
        thr = list_get_instance(cur, thread_t, th_link);
315
        if (thr == t)
316
            continue;
317
 
318
        spinlock_lock(&thr->lock);
319
        thr->interrupted = true;
320
        if (thr->state == Sleeping)
321
            sleeping = true;
322
        spinlock_unlock(&thr->lock);
323
 
324
        if (sleeping)
325
            waitq_interrupt_sleep(thr);
326
    }
327
 
1580 jermar 328
    spinlock_unlock(&ta->lock);
329
    interrupts_restore(ipl);
1579 jermar 330
 
1580 jermar 331
    if (t)
332
        thread_ready(t);
333
 
1579 jermar 334
    return 0;
335
}
336
 
1060 palkovsky 337
/** Print task list */
338
void task_print_list(void)
339
{
340
    link_t *cur;
341
    ipl_t ipl;
342
 
343
    /* Messing with thread structures, avoid deadlock */
344
    ipl = interrupts_disable();
345
    spinlock_lock(&tasks_lock);
346
 
1159 jermar 347
    for (cur = tasks_btree.leaf_head.next; cur != &tasks_btree.leaf_head; cur = cur->next) {
348
        btree_node_t *node;
349
        int i;
350
 
351
        node = list_get_instance(cur, btree_node_t, leaf_link);
352
        for (i = 0; i < node->keys; i++) {
353
            task_t *t;
354
            int j;
355
 
356
            t = (task_t *) node->value[i];
357
 
358
            spinlock_lock(&t->lock);
1820 decky 359
            printf("%s(%lld): context=%ld, address=%#zx, as=%#zx, ActiveCalls: %zd",
360
                t->name, t->taskid, t->context, t, t->as, atomic_get(&t->active_calls));
1159 jermar 361
            for (j=0; j < IPC_MAX_PHONES; j++) {
362
                if (t->phones[j].callee)
1735 decky 363
                    printf(" Ph(%zd): %#zx ", j, t->phones[j].callee);
1159 jermar 364
            }
365
            printf("\n");
366
            spinlock_unlock(&t->lock);
1060 palkovsky 367
        }
368
    }
369
 
370
    spinlock_unlock(&tasks_lock);
371
    interrupts_restore(ipl);
372
}
1579 jermar 373
 
1585 jermar 374
/** Kernel thread used to cleanup the task after it is killed. */
1580 jermar 375
void ktaskclnp(void *arg)
1579 jermar 376
{
1580 jermar 377
    ipl_t ipl;
1585 jermar 378
    thread_t *t = NULL, *main_thread;
1580 jermar 379
    link_t *cur;
1661 jermar 380
    bool again;
1580 jermar 381
 
382
    thread_detach(THREAD);
383
 
384
loop:
385
    ipl = interrupts_disable();
386
    spinlock_lock(&TASK->lock);
387
 
1585 jermar 388
    main_thread = TASK->main_thread;
389
 
1579 jermar 390
    /*
1580 jermar 391
     * Find a thread to join.
392
     */
1661 jermar 393
    again = false;
1580 jermar 394
    for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
395
        t = list_get_instance(cur, thread_t, th_link);
1661 jermar 396
 
397
        spinlock_lock(&t->lock);
398
        if (t == THREAD) {
399
            spinlock_unlock(&t->lock);
1580 jermar 400
            continue;
1661 jermar 401
        } else if (t == main_thread) {
402
            spinlock_unlock(&t->lock);
1585 jermar 403
            continue;
1661 jermar 404
        } else if (t->join_type != None) {
405
            spinlock_unlock(&t->lock);
406
            again = true;
407
            continue;
408
        } else {
409
            t->join_type = TaskClnp;
410
            spinlock_unlock(&t->lock);
411
            again = false;
1580 jermar 412
            break;
1661 jermar 413
        }
1580 jermar 414
    }
415
 
416
    spinlock_unlock(&TASK->lock);
417
    interrupts_restore(ipl);
418
 
1661 jermar 419
    if (again) {
420
        /*
421
         * Other cleanup (e.g. ktaskgc) is in progress.
422
         */
423
        scheduler();
424
        goto loop;
425
    }
426
 
1580 jermar 427
    if (t != THREAD) {
1661 jermar 428
        ASSERT(t != main_thread);   /* uninit is joined and detached in ktaskgc */
1580 jermar 429
        thread_join(t);
430
        thread_detach(t);
1585 jermar 431
        goto loop;  /* go for another thread */
1580 jermar 432
    }
433
 
434
    /*
435
     * Now there are no other threads in this task
436
     * and no new threads can be created.
437
     */
1880 jermar 438
 
1583 jermar 439
    ipc_cleanup();
440
    futex_cleanup();
1597 palkovsky 441
    klog_printf("Cleanup of task %lld completed.", TASK->taskid);
1579 jermar 442
}
1585 jermar 443
 
1684 jermar 444
/** Kernel thread used to kill the userspace task when its main thread exits.
1585 jermar 445
 *
446
 * This thread waits until the main userspace thread (i.e. uninit) exits.
1661 jermar 447
 * When this happens, the task is killed. In the meantime, exited threads
448
 * are garbage collected.
1585 jermar 449
 *
450
 * @param arg Pointer to the thread structure of the task's main thread.
451
 */
1661 jermar 452
void ktaskgc(void *arg)
1585 jermar 453
{
454
    thread_t *t = (thread_t *) arg;
1661 jermar 455
loop:  
1585 jermar 456
    /*
457
     * Userspace threads cannot detach themselves,
458
     * therefore the thread pointer is guaranteed to be valid.
459
     */
1661 jermar 460
    if (thread_join_timeout(t, 1000000, SYNCH_FLAGS_NONE) == ESYNCH_TIMEOUT) {  /* sleep uninterruptibly here! */
461
        ipl_t ipl;
462
        link_t *cur;
463
        thread_t *thr = NULL;
464
 
465
        /*
466
         * The join timed out. Try to do some garbage collection of Undead threads.
467
         */
468
more_gc:       
469
        ipl = interrupts_disable();
470
        spinlock_lock(&TASK->lock);
471
 
472
        for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
473
            thr = list_get_instance(cur, thread_t, th_link);
474
            spinlock_lock(&thr->lock);
1687 jermar 475
            if (thr != t && thr->state == Undead && thr->join_type == None) {
1661 jermar 476
                thr->join_type = TaskGC;
477
                spinlock_unlock(&thr->lock);
478
                break;
479
            }
480
            spinlock_unlock(&thr->lock);
481
            thr = NULL;
482
        }
483
        spinlock_unlock(&TASK->lock);
1676 jermar 484
        interrupts_restore(ipl);
1661 jermar 485
 
486
        if (thr) {
487
            thread_join(thr);
488
            thread_detach(thr);
489
            scheduler();
490
            goto more_gc;
491
        }
492
 
493
        goto loop;
494
    }
1585 jermar 495
    thread_detach(t);
496
    task_kill(TASK->taskid);
497
}
1702 cejka 498
 
1757 jermar 499
/** @}
1702 cejka 500
 */