FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_thr.c
1 /*-
2 * Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org>
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 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. 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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.2/sys/kern/kern_thr.c 284665 2015-06-21 06:28:26Z trasz $");
29
30 #include "opt_compat.h"
31 #include "opt_posix.h"
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/priv.h>
37 #include <sys/proc.h>
38 #include <sys/posix4.h>
39 #include <sys/racct.h>
40 #include <sys/resourcevar.h>
41 #include <sys/rwlock.h>
42 #include <sys/sched.h>
43 #include <sys/sysctl.h>
44 #include <sys/smp.h>
45 #include <sys/syscallsubr.h>
46 #include <sys/sysent.h>
47 #include <sys/systm.h>
48 #include <sys/sysproto.h>
49 #include <sys/signalvar.h>
50 #include <sys/sysctl.h>
51 #include <sys/ucontext.h>
52 #include <sys/thr.h>
53 #include <sys/rtprio.h>
54 #include <sys/umtx.h>
55 #include <sys/limits.h>
56
57 #include <machine/frame.h>
58
59 #include <security/audit/audit.h>
60
61 static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0,
62 "thread allocation");
63
64 static int max_threads_per_proc = 1500;
65 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW,
66 &max_threads_per_proc, 0, "Limit on threads per proc");
67
68 static int max_threads_hits;
69 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD,
70 &max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count");
71
72 #ifdef COMPAT_FREEBSD32
73
74 static inline int
75 suword_lwpid(void *addr, lwpid_t lwpid)
76 {
77 int error;
78
79 if (SV_CURPROC_FLAG(SV_LP64))
80 error = suword(addr, lwpid);
81 else
82 error = suword32(addr, lwpid);
83 return (error);
84 }
85
86 #else
87 #define suword_lwpid suword
88 #endif
89
90 static int create_thread(struct thread *td, mcontext_t *ctx,
91 void (*start_func)(void *), void *arg,
92 char *stack_base, size_t stack_size,
93 char *tls_base,
94 long *child_tid, long *parent_tid,
95 int flags, struct rtprio *rtp);
96
97 /*
98 * System call interface.
99 */
100 int
101 sys_thr_create(struct thread *td, struct thr_create_args *uap)
102 /* ucontext_t *ctx, long *id, int flags */
103 {
104 ucontext_t ctx;
105 int error;
106
107 if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
108 return (error);
109
110 error = create_thread(td, &ctx.uc_mcontext, NULL, NULL,
111 NULL, 0, NULL, uap->id, NULL, uap->flags, NULL);
112 return (error);
113 }
114
115 int
116 sys_thr_new(struct thread *td, struct thr_new_args *uap)
117 /* struct thr_param * */
118 {
119 struct thr_param param;
120 int error;
121
122 if (uap->param_size < 0 || uap->param_size > sizeof(param))
123 return (EINVAL);
124 bzero(¶m, sizeof(param));
125 if ((error = copyin(uap->param, ¶m, uap->param_size)))
126 return (error);
127 return (kern_thr_new(td, ¶m));
128 }
129
130 int
131 kern_thr_new(struct thread *td, struct thr_param *param)
132 {
133 struct rtprio rtp, *rtpp;
134 int error;
135
136 rtpp = NULL;
137 if (param->rtp != 0) {
138 error = copyin(param->rtp, &rtp, sizeof(struct rtprio));
139 if (error)
140 return (error);
141 rtpp = &rtp;
142 }
143 error = create_thread(td, NULL, param->start_func, param->arg,
144 param->stack_base, param->stack_size, param->tls_base,
145 param->child_tid, param->parent_tid, param->flags,
146 rtpp);
147 return (error);
148 }
149
150 static int
151 create_thread(struct thread *td, mcontext_t *ctx,
152 void (*start_func)(void *), void *arg,
153 char *stack_base, size_t stack_size,
154 char *tls_base,
155 long *child_tid, long *parent_tid,
156 int flags, struct rtprio *rtp)
157 {
158 stack_t stack;
159 struct thread *newtd;
160 struct proc *p;
161 int error;
162
163 p = td->td_proc;
164
165 /* Have race condition but it is cheap. */
166 if (p->p_numthreads >= max_threads_per_proc) {
167 ++max_threads_hits;
168 return (EPROCLIM);
169 }
170
171 if (rtp != NULL) {
172 switch(rtp->type) {
173 case RTP_PRIO_REALTIME:
174 case RTP_PRIO_FIFO:
175 /* Only root can set scheduler policy */
176 if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0)
177 return (EPERM);
178 if (rtp->prio > RTP_PRIO_MAX)
179 return (EINVAL);
180 break;
181 case RTP_PRIO_NORMAL:
182 rtp->prio = 0;
183 break;
184 default:
185 return (EINVAL);
186 }
187 }
188
189 #ifdef RACCT
190 PROC_LOCK(td->td_proc);
191 error = racct_add(p, RACCT_NTHR, 1);
192 PROC_UNLOCK(td->td_proc);
193 if (error != 0)
194 return (EPROCLIM);
195 #endif
196
197 /* Initialize our td */
198 newtd = thread_alloc(0);
199 if (newtd == NULL) {
200 error = ENOMEM;
201 goto fail;
202 }
203
204 cpu_set_upcall(newtd, td);
205
206 /*
207 * Try the copyout as soon as we allocate the td so we don't
208 * have to tear things down in a failure case below.
209 * Here we copy out tid to two places, one for child and one
210 * for parent, because pthread can create a detached thread,
211 * if parent wants to safely access child tid, it has to provide
212 * its storage, because child thread may exit quickly and
213 * memory is freed before parent thread can access it.
214 */
215 if ((child_tid != NULL &&
216 suword_lwpid(child_tid, newtd->td_tid)) ||
217 (parent_tid != NULL &&
218 suword_lwpid(parent_tid, newtd->td_tid))) {
219 thread_free(newtd);
220 error = EFAULT;
221 goto fail;
222 }
223
224 bzero(&newtd->td_startzero,
225 __rangeof(struct thread, td_startzero, td_endzero));
226 newtd->td_su = NULL;
227 bcopy(&td->td_startcopy, &newtd->td_startcopy,
228 __rangeof(struct thread, td_startcopy, td_endcopy));
229 newtd->td_proc = td->td_proc;
230 newtd->td_ucred = crhold(td->td_ucred);
231
232 if (ctx != NULL) { /* old way to set user context */
233 error = set_mcontext(newtd, ctx);
234 if (error != 0) {
235 thread_free(newtd);
236 crfree(td->td_ucred);
237 goto fail;
238 }
239 } else {
240 /* Set up our machine context. */
241 stack.ss_sp = stack_base;
242 stack.ss_size = stack_size;
243 /* Set upcall address to user thread entry function. */
244 cpu_set_upcall_kse(newtd, start_func, arg, &stack);
245 /* Setup user TLS address and TLS pointer register. */
246 error = cpu_set_user_tls(newtd, tls_base);
247 if (error != 0) {
248 thread_free(newtd);
249 crfree(td->td_ucred);
250 goto fail;
251 }
252 }
253
254 PROC_LOCK(td->td_proc);
255 td->td_proc->p_flag |= P_HADTHREADS;
256 thread_link(newtd, p);
257 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
258 thread_lock(td);
259 /* let the scheduler know about these things. */
260 sched_fork_thread(td, newtd);
261 thread_unlock(td);
262 if (P_SHOULDSTOP(p))
263 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
264 PROC_UNLOCK(p);
265
266 tidhash_add(newtd);
267
268 thread_lock(newtd);
269 if (rtp != NULL) {
270 if (!(td->td_pri_class == PRI_TIMESHARE &&
271 rtp->type == RTP_PRIO_NORMAL)) {
272 rtp_to_pri(rtp, newtd);
273 sched_prio(newtd, newtd->td_user_pri);
274 } /* ignore timesharing class */
275 }
276 TD_SET_CAN_RUN(newtd);
277 sched_add(newtd, SRQ_BORING);
278 thread_unlock(newtd);
279
280 return (0);
281
282 fail:
283 #ifdef RACCT
284 if (racct_enable) {
285 PROC_LOCK(p);
286 racct_sub(p, RACCT_NTHR, 1);
287 PROC_UNLOCK(p);
288 }
289 #endif
290 return (error);
291 }
292
293 int
294 sys_thr_self(struct thread *td, struct thr_self_args *uap)
295 /* long *id */
296 {
297 int error;
298
299 error = suword_lwpid(uap->id, (unsigned)td->td_tid);
300 if (error == -1)
301 return (EFAULT);
302 return (0);
303 }
304
305 int
306 sys_thr_exit(struct thread *td, struct thr_exit_args *uap)
307 /* long *state */
308 {
309 struct proc *p;
310
311 p = td->td_proc;
312
313 /* Signal userland that it can free the stack. */
314 if ((void *)uap->state != NULL) {
315 suword_lwpid(uap->state, 1);
316 kern_umtx_wake(td, uap->state, INT_MAX, 0);
317 }
318
319 rw_wlock(&tidhash_lock);
320
321 PROC_LOCK(p);
322
323 if (p->p_numthreads != 1) {
324 racct_sub(p, RACCT_NTHR, 1);
325 LIST_REMOVE(td, td_hash);
326 rw_wunlock(&tidhash_lock);
327 tdsigcleanup(td);
328 umtx_thread_exit(td);
329 PROC_SLOCK(p);
330 thread_stopped(p);
331 thread_exit();
332 /* NOTREACHED */
333 }
334
335 /*
336 * Ignore attempts to shut down last thread in the proc. This
337 * will actually call _exit(2) in the usermode trampoline when
338 * it returns.
339 */
340 PROC_UNLOCK(p);
341 rw_wunlock(&tidhash_lock);
342 return (0);
343 }
344
345 int
346 sys_thr_kill(struct thread *td, struct thr_kill_args *uap)
347 /* long id, int sig */
348 {
349 ksiginfo_t ksi;
350 struct thread *ttd;
351 struct proc *p;
352 int error;
353
354 p = td->td_proc;
355 ksiginfo_init(&ksi);
356 ksi.ksi_signo = uap->sig;
357 ksi.ksi_code = SI_LWP;
358 ksi.ksi_pid = p->p_pid;
359 ksi.ksi_uid = td->td_ucred->cr_ruid;
360 if (uap->id == -1) {
361 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
362 error = EINVAL;
363 } else {
364 error = ESRCH;
365 PROC_LOCK(p);
366 FOREACH_THREAD_IN_PROC(p, ttd) {
367 if (ttd != td) {
368 error = 0;
369 if (uap->sig == 0)
370 break;
371 tdksignal(ttd, uap->sig, &ksi);
372 }
373 }
374 PROC_UNLOCK(p);
375 }
376 } else {
377 error = 0;
378 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
379 if (ttd == NULL)
380 return (ESRCH);
381 if (uap->sig == 0)
382 ;
383 else if (!_SIG_VALID(uap->sig))
384 error = EINVAL;
385 else
386 tdksignal(ttd, uap->sig, &ksi);
387 PROC_UNLOCK(ttd->td_proc);
388 }
389 return (error);
390 }
391
392 int
393 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap)
394 /* pid_t pid, long id, int sig */
395 {
396 ksiginfo_t ksi;
397 struct thread *ttd;
398 struct proc *p;
399 int error;
400
401 AUDIT_ARG_SIGNUM(uap->sig);
402
403 ksiginfo_init(&ksi);
404 ksi.ksi_signo = uap->sig;
405 ksi.ksi_code = SI_LWP;
406 ksi.ksi_pid = td->td_proc->p_pid;
407 ksi.ksi_uid = td->td_ucred->cr_ruid;
408 if (uap->id == -1) {
409 if ((p = pfind(uap->pid)) == NULL)
410 return (ESRCH);
411 AUDIT_ARG_PROCESS(p);
412 error = p_cansignal(td, p, uap->sig);
413 if (error) {
414 PROC_UNLOCK(p);
415 return (error);
416 }
417 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
418 error = EINVAL;
419 } else {
420 error = ESRCH;
421 FOREACH_THREAD_IN_PROC(p, ttd) {
422 if (ttd != td) {
423 error = 0;
424 if (uap->sig == 0)
425 break;
426 tdksignal(ttd, uap->sig, &ksi);
427 }
428 }
429 }
430 PROC_UNLOCK(p);
431 } else {
432 ttd = tdfind((lwpid_t)uap->id, uap->pid);
433 if (ttd == NULL)
434 return (ESRCH);
435 p = ttd->td_proc;
436 AUDIT_ARG_PROCESS(p);
437 error = p_cansignal(td, p, uap->sig);
438 if (uap->sig == 0)
439 ;
440 else if (!_SIG_VALID(uap->sig))
441 error = EINVAL;
442 else
443 tdksignal(ttd, uap->sig, &ksi);
444 PROC_UNLOCK(p);
445 }
446 return (error);
447 }
448
449 int
450 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap)
451 /* const struct timespec *timeout */
452 {
453 struct timespec ts, *tsp;
454 int error;
455
456 tsp = NULL;
457 if (uap->timeout != NULL) {
458 error = umtx_copyin_timeout(uap->timeout, &ts);
459 if (error != 0)
460 return (error);
461 tsp = &ts;
462 }
463
464 return (kern_thr_suspend(td, tsp));
465 }
466
467 int
468 kern_thr_suspend(struct thread *td, struct timespec *tsp)
469 {
470 struct proc *p = td->td_proc;
471 struct timeval tv;
472 int error = 0;
473 int timo = 0;
474
475 if (td->td_pflags & TDP_WAKEUP) {
476 td->td_pflags &= ~TDP_WAKEUP;
477 return (0);
478 }
479
480 if (tsp != NULL) {
481 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
482 error = EWOULDBLOCK;
483 else {
484 TIMESPEC_TO_TIMEVAL(&tv, tsp);
485 timo = tvtohz(&tv);
486 }
487 }
488
489 PROC_LOCK(p);
490 if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0)
491 error = msleep((void *)td, &p->p_mtx,
492 PCATCH, "lthr", timo);
493
494 if (td->td_flags & TDF_THRWAKEUP) {
495 thread_lock(td);
496 td->td_flags &= ~TDF_THRWAKEUP;
497 thread_unlock(td);
498 PROC_UNLOCK(p);
499 return (0);
500 }
501 PROC_UNLOCK(p);
502 if (error == EWOULDBLOCK)
503 error = ETIMEDOUT;
504 else if (error == ERESTART) {
505 if (timo != 0)
506 error = EINTR;
507 }
508 return (error);
509 }
510
511 int
512 sys_thr_wake(struct thread *td, struct thr_wake_args *uap)
513 /* long id */
514 {
515 struct proc *p;
516 struct thread *ttd;
517
518 if (uap->id == td->td_tid) {
519 td->td_pflags |= TDP_WAKEUP;
520 return (0);
521 }
522
523 p = td->td_proc;
524 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
525 if (ttd == NULL)
526 return (ESRCH);
527 thread_lock(ttd);
528 ttd->td_flags |= TDF_THRWAKEUP;
529 thread_unlock(ttd);
530 wakeup((void *)ttd);
531 PROC_UNLOCK(p);
532 return (0);
533 }
534
535 int
536 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap)
537 {
538 struct proc *p;
539 char name[MAXCOMLEN + 1];
540 struct thread *ttd;
541 int error;
542
543 error = 0;
544 name[0] = '\0';
545 if (uap->name != NULL) {
546 error = copyinstr(uap->name, name, sizeof(name),
547 NULL);
548 if (error)
549 return (error);
550 }
551 p = td->td_proc;
552 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
553 if (ttd == NULL)
554 return (ESRCH);
555 strcpy(ttd->td_name, name);
556 #ifdef KTR
557 sched_clear_tdname(ttd);
558 #endif
559 PROC_UNLOCK(p);
560 return (error);
561 }
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