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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>
2000 decky 53
#include <lib/elf.h>
1579 jermar 54
#include <errno.h>
2050 decky 55
#include <func.h>
1288 jermar 56
#include <syscall/copy.h>
1597 palkovsky 57
#include <console/klog.h>
973 palkovsky 58
 
1170 vana 59
#ifndef LOADED_PROG_STACK_PAGES_NO
60
#define LOADED_PROG_STACK_PAGES_NO 1
61
#endif
1168 vana 62
 
1636 jermar 63
/** Spinlock protecting the tasks_btree B+tree. */
623 jermar 64
SPINLOCK_INITIALIZE(tasks_lock);
1636 jermar 65
 
66
/** B+tree of active tasks.
67
 *
68
 * The task is guaranteed to exist after it was found in the tasks_btree as long as:
69
 * @li the tasks_lock is held,
70
 * @li the task's lock is held when task's lock is acquired before releasing tasks_lock or
1880 jermar 71
 * @li the task's refcount is greater than 0
1636 jermar 72
 *
73
 */
1159 jermar 74
btree_t tasks_btree;
1636 jermar 75
 
1005 palkovsky 76
static task_id_t task_counter = 0;
1 jermar 77
 
1585 jermar 78
static void ktaskclnp(void *arg);
1661 jermar 79
static void ktaskgc(void *arg);
1579 jermar 80
 
107 decky 81
/** Initialize tasks
82
 *
83
 * Initialize kernel tasks support.
84
 *
85
 */
1 jermar 86
void task_init(void)
87
{
15 jermar 88
    TASK = NULL;
1159 jermar 89
    btree_create(&tasks_btree);
1 jermar 90
}
91
 
107 decky 92
 
93
/** Create new task
94
 *
95
 * Create new task with no threads.
96
 *
703 jermar 97
 * @param as Task's address space.
1062 jermar 98
 * @param name Symbolic name.
107 decky 99
 *
973 palkovsky 100
 * @return New task's structure
107 decky 101
 *
102
 */
1062 jermar 103
task_t *task_create(as_t *as, char *name)
1 jermar 104
{
413 jermar 105
    ipl_t ipl;
1 jermar 106
    task_t *ta;
1040 palkovsky 107
    int i;
1 jermar 108
 
822 palkovsky 109
    ta = (task_t *) malloc(sizeof(task_t), 0);
110
 
1185 jermar 111
    task_create_arch(ta);
112
 
822 palkovsky 113
    spinlock_initialize(&ta->lock, "task_ta_lock");
114
    list_initialize(&ta->th_head);
115
    ta->as = as;
1062 jermar 116
    ta->name = name;
1585 jermar 117
    ta->main_thread = NULL;
1579 jermar 118
    ta->refcount = 0;
1839 decky 119
    ta->context = CONTEXT;
1579 jermar 120
 
1174 jermar 121
    ta->capabilities = 0;
1579 jermar 122
    ta->accept_new_threads = true;
2039 decky 123
    ta->cycles = 0;
1040 palkovsky 124
 
955 palkovsky 125
    ipc_answerbox_init(&ta->answerbox);
1839 decky 126
    for (i = 0; i < IPC_MAX_PHONES; i++)
1040 palkovsky 127
        ipc_phone_init(&ta->phones[i]);
1839 decky 128
    if ((ipc_phone_0) && (context_check(ipc_phone_0->task->context, ta->context)))
1040 palkovsky 129
        ipc_phone_connect(&ta->phones[0], ipc_phone_0);
998 palkovsky 130
    atomic_set(&ta->active_calls, 0);
1460 jermar 131
 
132
    mutex_initialize(&ta->futexes_lock);
133
    btree_create(&ta->futexes);
822 palkovsky 134
 
135
    ipl = interrupts_disable();
1468 jermar 136
 
137
    /*
138
     * Increment address space reference count.
139
     * TODO: Reconsider the locking scheme.
140
     */
141
    mutex_lock(&as->lock);
142
    as->refcount++;
143
    mutex_unlock(&as->lock);
144
 
822 palkovsky 145
    spinlock_lock(&tasks_lock);
1005 palkovsky 146
 
147
    ta->taskid = ++task_counter;
1177 jermar 148
    btree_insert(&tasks_btree, (btree_key_t) ta->taskid, (void *) ta, NULL);
1005 palkovsky 149
 
822 palkovsky 150
    spinlock_unlock(&tasks_lock);
151
    interrupts_restore(ipl);
152
 
1 jermar 153
    return ta;
154
}
155
 
1579 jermar 156
/** Destroy task.
157
 *
158
 * @param t Task to be destroyed.
159
 */
160
void task_destroy(task_t *t)
161
{
1587 jermar 162
    task_destroy_arch(t);
163
    btree_destroy(&t->futexes);
164
 
165
    mutex_lock_active(&t->as->lock);
166
    if (--t->as->refcount == 0) {
167
        mutex_unlock(&t->as->lock);
168
        as_destroy(t->as);
169
        /*
170
         * t->as is destroyed.
171
         */
2040 decky 172
    } else
1587 jermar 173
        mutex_unlock(&t->as->lock);
174
 
175
    free(t);
176
    TASK = NULL;
1579 jermar 177
}
178
 
973 palkovsky 179
/** Create new task with 1 thread and run it
180
 *
1248 jermar 181
 * @param program_addr Address of program executable image.
1062 jermar 182
 * @param name Program name.
183
 *
1229 jermar 184
 * @return Task of the running program or NULL on error.
973 palkovsky 185
 */
1062 jermar 186
task_t * task_run_program(void *program_addr, char *name)
973 palkovsky 187
{
188
    as_t *as;
189
    as_area_t *a;
190
    int rc;
1585 jermar 191
    thread_t *t1, *t2;
973 palkovsky 192
    task_t *task;
1078 jermar 193
    uspace_arg_t *kernel_uarg;
973 palkovsky 194
 
195
    as = as_create(0);
1115 jermar 196
    ASSERT(as);
973 palkovsky 197
 
1025 palkovsky 198
    rc = elf_load((elf_header_t *) program_addr, as);
973 palkovsky 199
    if (rc != EE_OK) {
1468 jermar 200
        as_destroy(as);
973 palkovsky 201
        return NULL;
202
    }
203
 
1078 jermar 204
    kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
205
    kernel_uarg->uspace_entry = (void *) ((elf_header_t *) program_addr)->e_entry;
206
    kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
207
    kernel_uarg->uspace_thread_function = NULL;
208
    kernel_uarg->uspace_thread_arg = NULL;
209
    kernel_uarg->uspace_uarg = NULL;
1066 jermar 210
 
1062 jermar 211
    task = task_create(as, name);
1115 jermar 212
    ASSERT(task);
213
 
973 palkovsky 214
    /*
215
     * Create the data as_area.
216
     */
1424 jermar 217
    a = as_area_create(as, AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
218
        LOADED_PROG_STACK_PAGES_NO*PAGE_SIZE,
1409 jermar 219
        USTACK_ADDRESS, AS_AREA_ATTR_NONE, &anon_backend, NULL);
1115 jermar 220
 
1585 jermar 221
    /*
222
     * Create the main thread.
223
     */
2042 decky 224
    t1 = thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE, "uinit", false);
1585 jermar 225
    ASSERT(t1);
973 palkovsky 226
 
1585 jermar 227
    /*
228
     * Create killer thread for the new task.
229
     */
2042 decky 230
    t2 = thread_create(ktaskgc, t1, task, 0, "ktaskgc", true);
1585 jermar 231
    ASSERT(t2);
232
    thread_ready(t2);
233
 
234
    thread_ready(t1);
235
 
973 palkovsky 236
    return task;
237
}
1060 palkovsky 238
 
1176 jermar 239
/** Syscall for reading task ID from userspace.
240
 *
1248 jermar 241
 * @param uspace_task_id Userspace address of 8-byte buffer where to store current task ID.
1176 jermar 242
 *
1288 jermar 243
 * @return 0 on success or an error code from @ref errno.h.
1176 jermar 244
 */
1780 jermar 245
unative_t sys_task_get_id(task_id_t *uspace_task_id)
1176 jermar 246
{
247
    /*
248
     * No need to acquire lock on TASK because taskid
249
     * remains constant for the lifespan of the task.
250
     */
1780 jermar 251
    return (unative_t) copy_to_uspace(uspace_task_id, &TASK->taskid, sizeof(TASK->taskid));
1176 jermar 252
}
253
 
1178 jermar 254
/** Find task structure corresponding to task ID.
255
 *
256
 * The tasks_lock must be already held by the caller of this function
257
 * and interrupts must be disabled.
258
 *
259
 * @param id Task ID.
260
 *
261
 * @return Task structure address or NULL if there is no such task ID.
262
 */
263
task_t *task_find_by_id(task_id_t id)
264
{
265
    btree_node_t *leaf;
266
 
267
    return (task_t *) btree_search(&tasks_btree, (btree_key_t) id, &leaf);
268
}
269
 
2039 decky 270
/** Get accounting data of given task.
271
 *
2048 jermar 272
 * Note that task lock of 't' must be already held and
2039 decky 273
 * interrupts must be already disabled.
274
 *
275
 * @param t Pointer to thread.
276
 *
277
 */
278
uint64_t task_get_accounting(task_t *t)
279
{
280
    /* Accumulated value of task */
281
    uint64_t ret = t->cycles;
282
 
283
    /* Current values of threads */
284
    link_t *cur;
285
    for (cur = t->th_head.next; cur != &t->th_head; cur = cur->next) {
286
        thread_t *thr = list_get_instance(cur, thread_t, th_link);
287
 
288
        spinlock_lock(&thr->lock);
2042 decky 289
        /* Process only counted threads */
290
        if (!thr->uncounted) {
291
            if (thr == THREAD) /* Update accounting of current thread */
292
                thread_update_accounting();
293
            ret += thr->cycles;
294
        }
2039 decky 295
        spinlock_unlock(&thr->lock);
296
    }
297
 
298
    return ret;
299
}
300
 
1579 jermar 301
/** Kill task.
302
 *
303
 * @param id ID of the task to be killed.
304
 *
305
 * @return 0 on success or an error code from errno.h
306
 */
307
int task_kill(task_id_t id)
308
{
309
    ipl_t ipl;
310
    task_t *ta;
311
    thread_t *t;
312
    link_t *cur;
1600 jermar 313
 
314
    if (id == 1)
315
        return EPERM;
1579 jermar 316
 
317
    ipl = interrupts_disable();
318
    spinlock_lock(&tasks_lock);
319
 
320
    if (!(ta = task_find_by_id(id))) {
321
        spinlock_unlock(&tasks_lock);
322
        interrupts_restore(ipl);
323
        return ENOENT;
324
    }
1588 jermar 325
 
1579 jermar 326
    spinlock_lock(&ta->lock);
327
    ta->refcount++;
328
    spinlock_unlock(&ta->lock);
1587 jermar 329
 
1588 jermar 330
    btree_remove(&tasks_btree, ta->taskid, NULL);
1587 jermar 331
    spinlock_unlock(&tasks_lock);
1579 jermar 332
 
2042 decky 333
    t = thread_create(ktaskclnp, NULL, ta, 0, "ktaskclnp", true);
1579 jermar 334
 
335
    spinlock_lock(&ta->lock);
1580 jermar 336
    ta->accept_new_threads = false;
1579 jermar 337
    ta->refcount--;
1585 jermar 338
 
339
    /*
1687 jermar 340
     * Interrupt all threads except ktaskclnp.
1585 jermar 341
     */
1579 jermar 342
    for (cur = ta->th_head.next; cur != &ta->th_head; cur = cur->next) {
343
        thread_t *thr;
344
        bool  sleeping = false;
345
 
346
        thr = list_get_instance(cur, thread_t, th_link);
347
        if (thr == t)
348
            continue;
349
 
350
        spinlock_lock(&thr->lock);
351
        thr->interrupted = true;
352
        if (thr->state == Sleeping)
353
            sleeping = true;
354
        spinlock_unlock(&thr->lock);
355
 
356
        if (sleeping)
357
            waitq_interrupt_sleep(thr);
358
    }
359
 
1580 jermar 360
    spinlock_unlock(&ta->lock);
361
    interrupts_restore(ipl);
1579 jermar 362
 
1580 jermar 363
    if (t)
364
        thread_ready(t);
365
 
1579 jermar 366
    return 0;
367
}
368
 
1060 palkovsky 369
/** Print task list */
370
void task_print_list(void)
371
{
372
    link_t *cur;
373
    ipl_t ipl;
374
 
375
    /* Messing with thread structures, avoid deadlock */
376
    ipl = interrupts_disable();
377
    spinlock_lock(&tasks_lock);
2035 decky 378
 
2039 decky 379
    printf("taskid name       ctx address    as         cycles     threads calls  callee\n");
380
    printf("------ ---------- --- ---------- ---------- ---------- ------- ------ ------>\n");
1060 palkovsky 381
 
1159 jermar 382
    for (cur = tasks_btree.leaf_head.next; cur != &tasks_btree.leaf_head; cur = cur->next) {
383
        btree_node_t *node;
384
        int i;
385
 
386
        node = list_get_instance(cur, btree_node_t, leaf_link);
387
        for (i = 0; i < node->keys; i++) {
388
            task_t *t;
389
            int j;
390
 
391
            t = (task_t *) node->value[i];
392
 
393
            spinlock_lock(&t->lock);
2039 decky 394
 
2050 decky 395
            uint64_t cycles;
2039 decky 396
            char suffix;
2050 decky 397
            order(task_get_accounting(t), &cycles, &suffix);
2039 decky 398
 
399
            printf("%-6lld %-10s %-3ld %#10zx %#10zx %9llu%c %7zd %6zd", t->taskid, t->name, t->context, t, t->as, cycles, suffix, t->refcount, atomic_get(&t->active_calls));
2035 decky 400
            for (j = 0; j < IPC_MAX_PHONES; j++) {
1159 jermar 401
                if (t->phones[j].callee)
2035 decky 402
                    printf(" %zd:%#zx", j, t->phones[j].callee);
1159 jermar 403
            }
404
            printf("\n");
2039 decky 405
 
1159 jermar 406
            spinlock_unlock(&t->lock);
1060 palkovsky 407
        }
408
    }
409
 
410
    spinlock_unlock(&tasks_lock);
411
    interrupts_restore(ipl);
412
}
1579 jermar 413
 
1585 jermar 414
/** Kernel thread used to cleanup the task after it is killed. */
1580 jermar 415
void ktaskclnp(void *arg)
1579 jermar 416
{
1580 jermar 417
    ipl_t ipl;
1585 jermar 418
    thread_t *t = NULL, *main_thread;
1580 jermar 419
    link_t *cur;
1661 jermar 420
    bool again;
1580 jermar 421
 
422
    thread_detach(THREAD);
423
 
424
loop:
425
    ipl = interrupts_disable();
426
    spinlock_lock(&TASK->lock);
427
 
1585 jermar 428
    main_thread = TASK->main_thread;
429
 
1579 jermar 430
    /*
1580 jermar 431
     * Find a thread to join.
432
     */
1661 jermar 433
    again = false;
1580 jermar 434
    for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
435
        t = list_get_instance(cur, thread_t, th_link);
1661 jermar 436
 
437
        spinlock_lock(&t->lock);
438
        if (t == THREAD) {
439
            spinlock_unlock(&t->lock);
1580 jermar 440
            continue;
1661 jermar 441
        } else if (t == main_thread) {
442
            spinlock_unlock(&t->lock);
1585 jermar 443
            continue;
1661 jermar 444
        } else if (t->join_type != None) {
445
            spinlock_unlock(&t->lock);
446
            again = true;
447
            continue;
448
        } else {
449
            t->join_type = TaskClnp;
450
            spinlock_unlock(&t->lock);
451
            again = false;
1580 jermar 452
            break;
1661 jermar 453
        }
1580 jermar 454
    }
455
 
456
    spinlock_unlock(&TASK->lock);
457
    interrupts_restore(ipl);
458
 
1661 jermar 459
    if (again) {
460
        /*
461
         * Other cleanup (e.g. ktaskgc) is in progress.
462
         */
463
        scheduler();
464
        goto loop;
465
    }
466
 
1580 jermar 467
    if (t != THREAD) {
1661 jermar 468
        ASSERT(t != main_thread);   /* uninit is joined and detached in ktaskgc */
1580 jermar 469
        thread_join(t);
470
        thread_detach(t);
1585 jermar 471
        goto loop;  /* go for another thread */
1580 jermar 472
    }
473
 
474
    /*
475
     * Now there are no other threads in this task
476
     * and no new threads can be created.
477
     */
1880 jermar 478
 
1583 jermar 479
    ipc_cleanup();
480
    futex_cleanup();
1597 palkovsky 481
    klog_printf("Cleanup of task %lld completed.", TASK->taskid);
1579 jermar 482
}
1585 jermar 483
 
1684 jermar 484
/** Kernel thread used to kill the userspace task when its main thread exits.
1585 jermar 485
 *
486
 * This thread waits until the main userspace thread (i.e. uninit) exits.
1661 jermar 487
 * When this happens, the task is killed. In the meantime, exited threads
488
 * are garbage collected.
1585 jermar 489
 *
490
 * @param arg Pointer to the thread structure of the task's main thread.
491
 */
1661 jermar 492
void ktaskgc(void *arg)
1585 jermar 493
{
494
    thread_t *t = (thread_t *) arg;
1661 jermar 495
loop:  
1585 jermar 496
    /*
497
     * Userspace threads cannot detach themselves,
498
     * therefore the thread pointer is guaranteed to be valid.
499
     */
1661 jermar 500
    if (thread_join_timeout(t, 1000000, SYNCH_FLAGS_NONE) == ESYNCH_TIMEOUT) {  /* sleep uninterruptibly here! */
501
        ipl_t ipl;
502
        link_t *cur;
503
        thread_t *thr = NULL;
504
 
505
        /*
506
         * The join timed out. Try to do some garbage collection of Undead threads.
507
         */
508
more_gc:       
509
        ipl = interrupts_disable();
510
        spinlock_lock(&TASK->lock);
511
 
512
        for (cur = TASK->th_head.next; cur != &TASK->th_head; cur = cur->next) {
513
            thr = list_get_instance(cur, thread_t, th_link);
514
            spinlock_lock(&thr->lock);
1687 jermar 515
            if (thr != t && thr->state == Undead && thr->join_type == None) {
1661 jermar 516
                thr->join_type = TaskGC;
517
                spinlock_unlock(&thr->lock);
518
                break;
519
            }
520
            spinlock_unlock(&thr->lock);
521
            thr = NULL;
522
        }
523
        spinlock_unlock(&TASK->lock);
1676 jermar 524
        interrupts_restore(ipl);
1661 jermar 525
 
526
        if (thr) {
527
            thread_join(thr);
528
            thread_detach(thr);
529
            scheduler();
530
            goto more_gc;
531
        }
532
 
533
        goto loop;
534
    }
1585 jermar 535
    thread_detach(t);
536
    task_kill(TASK->taskid);
537
}
1702 cejka 538
 
1757 jermar 539
/** @}
1702 cejka 540
 */