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("$FreeBSD$");
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, "");
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 bcopy(&td->td_startcopy, &newtd->td_startcopy,
227 __rangeof(struct thread, td_startcopy, td_endcopy));
228 newtd->td_proc = td->td_proc;
229 newtd->td_ucred = crhold(td->td_ucred);
230 newtd->td_dbg_sc_code = td->td_dbg_sc_code;
231 newtd->td_dbg_sc_narg = td->td_dbg_sc_narg;
232
233 if (ctx != NULL) { /* old way to set user context */
234 error = set_mcontext(newtd, ctx);
235 if (error != 0) {
236 thread_free(newtd);
237 crfree(td->td_ucred);
238 goto fail;
239 }
240 } else {
241 /* Set up our machine context. */
242 stack.ss_sp = stack_base;
243 stack.ss_size = stack_size;
244 /* Set upcall address to user thread entry function. */
245 cpu_set_upcall_kse(newtd, start_func, arg, &stack);
246 /* Setup user TLS address and TLS pointer register. */
247 error = cpu_set_user_tls(newtd, tls_base);
248 if (error != 0) {
249 thread_free(newtd);
250 crfree(td->td_ucred);
251 goto fail;
252 }
253 }
254
255 PROC_LOCK(td->td_proc);
256 td->td_proc->p_flag |= P_HADTHREADS;
257 newtd->td_sigmask = td->td_sigmask;
258 thread_link(newtd, p);
259 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
260 thread_lock(td);
261 /* let the scheduler know about these things. */
262 sched_fork_thread(td, newtd);
263 thread_unlock(td);
264 if (P_SHOULDSTOP(p))
265 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
266 PROC_UNLOCK(p);
267
268 tidhash_add(newtd);
269
270 thread_lock(newtd);
271 if (rtp != NULL) {
272 if (!(td->td_pri_class == PRI_TIMESHARE &&
273 rtp->type == RTP_PRIO_NORMAL)) {
274 rtp_to_pri(rtp, newtd);
275 sched_prio(newtd, newtd->td_user_pri);
276 } /* ignore timesharing class */
277 }
278 TD_SET_CAN_RUN(newtd);
279 sched_add(newtd, SRQ_BORING);
280 thread_unlock(newtd);
281
282 return (0);
283
284 fail:
285 #ifdef RACCT
286 PROC_LOCK(p);
287 racct_sub(p, RACCT_NTHR, 1);
288 PROC_UNLOCK(p);
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 /*
324 * Shutting down last thread in the proc. This will actually
325 * call exit() in the trampoline when it returns.
326 */
327 if (p->p_numthreads != 1) {
328 racct_sub(p, RACCT_NTHR, 1);
329 LIST_REMOVE(td, td_hash);
330 rw_wunlock(&tidhash_lock);
331 tdsigcleanup(td);
332 PROC_SLOCK(p);
333 thread_stopped(p);
334 thread_exit();
335 /* NOTREACHED */
336 }
337 PROC_UNLOCK(p);
338 rw_wunlock(&tidhash_lock);
339 return (0);
340 }
341
342 int
343 sys_thr_kill(struct thread *td, struct thr_kill_args *uap)
344 /* long id, int sig */
345 {
346 ksiginfo_t ksi;
347 struct thread *ttd;
348 struct proc *p;
349 int error;
350
351 p = td->td_proc;
352 ksiginfo_init(&ksi);
353 ksi.ksi_signo = uap->sig;
354 ksi.ksi_code = SI_LWP;
355 ksi.ksi_pid = p->p_pid;
356 ksi.ksi_uid = td->td_ucred->cr_ruid;
357 if (uap->id == -1) {
358 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
359 error = EINVAL;
360 } else {
361 error = ESRCH;
362 PROC_LOCK(p);
363 FOREACH_THREAD_IN_PROC(p, ttd) {
364 if (ttd != td) {
365 error = 0;
366 if (uap->sig == 0)
367 break;
368 tdksignal(ttd, uap->sig, &ksi);
369 }
370 }
371 PROC_UNLOCK(p);
372 }
373 } else {
374 error = 0;
375 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
376 if (ttd == NULL)
377 return (ESRCH);
378 if (uap->sig == 0)
379 ;
380 else if (!_SIG_VALID(uap->sig))
381 error = EINVAL;
382 else
383 tdksignal(ttd, uap->sig, &ksi);
384 PROC_UNLOCK(ttd->td_proc);
385 }
386 return (error);
387 }
388
389 int
390 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap)
391 /* pid_t pid, long id, int sig */
392 {
393 ksiginfo_t ksi;
394 struct thread *ttd;
395 struct proc *p;
396 int error;
397
398 AUDIT_ARG_SIGNUM(uap->sig);
399
400 ksiginfo_init(&ksi);
401 ksi.ksi_signo = uap->sig;
402 ksi.ksi_code = SI_LWP;
403 ksi.ksi_pid = td->td_proc->p_pid;
404 ksi.ksi_uid = td->td_ucred->cr_ruid;
405 if (uap->id == -1) {
406 if ((p = pfind(uap->pid)) == NULL)
407 return (ESRCH);
408 AUDIT_ARG_PROCESS(p);
409 error = p_cansignal(td, p, uap->sig);
410 if (error) {
411 PROC_UNLOCK(p);
412 return (error);
413 }
414 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
415 error = EINVAL;
416 } else {
417 error = ESRCH;
418 FOREACH_THREAD_IN_PROC(p, ttd) {
419 if (ttd != td) {
420 error = 0;
421 if (uap->sig == 0)
422 break;
423 tdksignal(ttd, uap->sig, &ksi);
424 }
425 }
426 }
427 PROC_UNLOCK(p);
428 } else {
429 ttd = tdfind((lwpid_t)uap->id, uap->pid);
430 if (ttd == NULL)
431 return (ESRCH);
432 p = ttd->td_proc;
433 AUDIT_ARG_PROCESS(p);
434 error = p_cansignal(td, p, uap->sig);
435 if (uap->sig == 0)
436 ;
437 else if (!_SIG_VALID(uap->sig))
438 error = EINVAL;
439 else
440 tdksignal(ttd, uap->sig, &ksi);
441 PROC_UNLOCK(p);
442 }
443 return (error);
444 }
445
446 int
447 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap)
448 /* const struct timespec *timeout */
449 {
450 struct timespec ts, *tsp;
451 int error;
452
453 tsp = NULL;
454 if (uap->timeout != NULL) {
455 error = umtx_copyin_timeout(uap->timeout, &ts);
456 if (error != 0)
457 return (error);
458 tsp = &ts;
459 }
460
461 return (kern_thr_suspend(td, tsp));
462 }
463
464 int
465 kern_thr_suspend(struct thread *td, struct timespec *tsp)
466 {
467 struct proc *p = td->td_proc;
468 struct timeval tv;
469 int error = 0;
470 int timo = 0;
471
472 if (td->td_pflags & TDP_WAKEUP) {
473 td->td_pflags &= ~TDP_WAKEUP;
474 return (0);
475 }
476
477 if (tsp != NULL) {
478 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
479 error = EWOULDBLOCK;
480 else {
481 TIMESPEC_TO_TIMEVAL(&tv, tsp);
482 timo = tvtohz(&tv);
483 }
484 }
485
486 PROC_LOCK(p);
487 if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0)
488 error = msleep((void *)td, &p->p_mtx,
489 PCATCH, "lthr", timo);
490
491 if (td->td_flags & TDF_THRWAKEUP) {
492 thread_lock(td);
493 td->td_flags &= ~TDF_THRWAKEUP;
494 thread_unlock(td);
495 PROC_UNLOCK(p);
496 return (0);
497 }
498 PROC_UNLOCK(p);
499 if (error == EWOULDBLOCK)
500 error = ETIMEDOUT;
501 else if (error == ERESTART) {
502 if (timo != 0)
503 error = EINTR;
504 }
505 return (error);
506 }
507
508 int
509 sys_thr_wake(struct thread *td, struct thr_wake_args *uap)
510 /* long id */
511 {
512 struct proc *p;
513 struct thread *ttd;
514
515 if (uap->id == td->td_tid) {
516 td->td_pflags |= TDP_WAKEUP;
517 return (0);
518 }
519
520 p = td->td_proc;
521 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
522 if (ttd == NULL)
523 return (ESRCH);
524 thread_lock(ttd);
525 ttd->td_flags |= TDF_THRWAKEUP;
526 thread_unlock(ttd);
527 wakeup((void *)ttd);
528 PROC_UNLOCK(p);
529 return (0);
530 }
531
532 int
533 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap)
534 {
535 struct proc *p;
536 char name[MAXCOMLEN + 1];
537 struct thread *ttd;
538 int error;
539
540 error = 0;
541 name[0] = '\0';
542 if (uap->name != NULL) {
543 error = copyinstr(uap->name, name, sizeof(name),
544 NULL);
545 if (error)
546 return (error);
547 }
548 p = td->td_proc;
549 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
550 if (ttd == NULL)
551 return (ESRCH);
552 strcpy(ttd->td_name, name);
553 #ifdef KTR
554 sched_clear_tdname(ttd);
555 #endif
556 PROC_UNLOCK(p);
557 return (error);
558 }
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