kern_thr.c revision 286843 
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: stable/10/sys/kern/kern_thr.c 286843 2015-08-17 12:51:46Z ed $");
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
61static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0,
62    "thread allocation");
63
64static int max_threads_per_proc = 1500;
65SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW,
66    &max_threads_per_proc, 0, "Limit on threads per proc");
67
68static int max_threads_hits;
69SYSCTL_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
74static inline int
75suword_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/*
91 * System call interface.
92 */
93
94struct thr_create_initthr_args {
95	ucontext_t ctx;
96	long *tid;
97};
98
99static int
100thr_create_initthr(struct thread *td, void *thunk)
101{
102	struct thr_create_initthr_args *args;
103
104	/* Copy out the child tid. */
105	args = thunk;
106	if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid))
107		return (EFAULT);
108
109	return (set_mcontext(td, &args->ctx.uc_mcontext));
110}
111
112int
113sys_thr_create(struct thread *td, struct thr_create_args *uap)
114    /* ucontext_t *ctx, long *id, int flags */
115{
116	struct thr_create_initthr_args args;
117	int error;
118
119	if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx))))
120		return (error);
121	args.tid = uap->id;
122	return (thread_create(td, NULL, thr_create_initthr, &args));
123}
124
125int
126sys_thr_new(struct thread *td, struct thr_new_args *uap)
127    /* struct thr_param * */
128{
129	struct thr_param param;
130	int error;
131
132	if (uap->param_size < 0 || uap->param_size > sizeof(param))
133		return (EINVAL);
134	bzero(&param, sizeof(param));
135	if ((error = copyin(uap->param, &param, uap->param_size)))
136		return (error);
137	return (kern_thr_new(td, &param));
138}
139
140static int
141thr_new_initthr(struct thread *td, void *thunk)
142{
143	stack_t stack;
144	struct thr_param *param;
145
146	/*
147	 * Here we copy out tid to two places, one for child and one
148	 * for parent, because pthread can create a detached thread,
149	 * if parent wants to safely access child tid, it has to provide
150	 * its storage, because child thread may exit quickly and
151	 * memory is freed before parent thread can access it.
152	 */
153	param = thunk;
154	if ((param->child_tid != NULL &&
155	    suword_lwpid(param->child_tid, td->td_tid)) ||
156	    (param->parent_tid != NULL &&
157	    suword_lwpid(param->parent_tid, td->td_tid)))
158		return (EFAULT);
159
160	/* Set up our machine context. */
161	stack.ss_sp = param->stack_base;
162	stack.ss_size = param->stack_size;
163	/* Set upcall address to user thread entry function. */
164	cpu_set_upcall_kse(td, param->start_func, param->arg, &stack);
165	/* Setup user TLS address and TLS pointer register. */
166	return (cpu_set_user_tls(td, param->tls_base));
167}
168
169int
170kern_thr_new(struct thread *td, struct thr_param *param)
171{
172	struct rtprio rtp, *rtpp;
173	int error;
174
175	rtpp = NULL;
176	if (param->rtp != 0) {
177		error = copyin(param->rtp, &rtp, sizeof(struct rtprio));
178		if (error)
179			return (error);
180		rtpp = &rtp;
181	}
182	return (thread_create(td, rtpp, thr_new_initthr, param));
183}
184
185int
186thread_create(struct thread *td, struct rtprio *rtp,
187    int (*initialize_thread)(struct thread *, void *), void *thunk)
188{
189	struct thread *newtd;
190	struct proc *p;
191	int error;
192
193	p = td->td_proc;
194
195	/* Have race condition but it is cheap. */
196	if (p->p_numthreads >= max_threads_per_proc) {
197		++max_threads_hits;
198		return (EPROCLIM);
199	}
200
201	if (rtp != NULL) {
202		switch(rtp->type) {
203		case RTP_PRIO_REALTIME:
204		case RTP_PRIO_FIFO:
205			/* Only root can set scheduler policy */
206			if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0)
207				return (EPERM);
208			if (rtp->prio > RTP_PRIO_MAX)
209				return (EINVAL);
210			break;
211		case RTP_PRIO_NORMAL:
212			rtp->prio = 0;
213			break;
214		default:
215			return (EINVAL);
216		}
217	}
218
219#ifdef RACCT
220	PROC_LOCK(td->td_proc);
221	error = racct_add(p, RACCT_NTHR, 1);
222	PROC_UNLOCK(td->td_proc);
223	if (error != 0)
224		return (EPROCLIM);
225#endif
226
227	/* Initialize our td */
228	newtd = thread_alloc(0);
229	if (newtd == NULL) {
230		error = ENOMEM;
231		goto fail;
232	}
233
234	cpu_set_upcall(newtd, td);
235
236	bzero(&newtd->td_startzero,
237	    __rangeof(struct thread, td_startzero, td_endzero));
238	newtd->td_su = NULL;
239	bcopy(&td->td_startcopy, &newtd->td_startcopy,
240	    __rangeof(struct thread, td_startcopy, td_endcopy));
241	newtd->td_proc = td->td_proc;
242	newtd->td_ucred = crhold(td->td_ucred);
243
244	error = initialize_thread(newtd, thunk);
245	if (error != 0) {
246		thread_free(newtd);
247		crfree(td->td_ucred);
248		goto fail;
249	}
250
251	PROC_LOCK(td->td_proc);
252	td->td_proc->p_flag |= P_HADTHREADS;
253	thread_link(newtd, p);
254	bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
255	thread_lock(td);
256	/* let the scheduler know about these things. */
257	sched_fork_thread(td, newtd);
258	thread_unlock(td);
259	if (P_SHOULDSTOP(p))
260		newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
261	PROC_UNLOCK(p);
262
263	tidhash_add(newtd);
264
265	thread_lock(newtd);
266	if (rtp != NULL) {
267		if (!(td->td_pri_class == PRI_TIMESHARE &&
268		      rtp->type == RTP_PRIO_NORMAL)) {
269			rtp_to_pri(rtp, newtd);
270			sched_prio(newtd, newtd->td_user_pri);
271		} /* ignore timesharing class */
272	}
273	TD_SET_CAN_RUN(newtd);
274	sched_add(newtd, SRQ_BORING);
275	thread_unlock(newtd);
276
277	return (0);
278
279fail:
280#ifdef RACCT
281	if (racct_enable) {
282		PROC_LOCK(p);
283		racct_sub(p, RACCT_NTHR, 1);
284		PROC_UNLOCK(p);
285	}
286#endif
287	return (error);
288}
289
290int
291sys_thr_self(struct thread *td, struct thr_self_args *uap)
292    /* long *id */
293{
294	int error;
295
296	error = suword_lwpid(uap->id, (unsigned)td->td_tid);
297	if (error == -1)
298		return (EFAULT);
299	return (0);
300}
301
302int
303sys_thr_exit(struct thread *td, struct thr_exit_args *uap)
304    /* long *state */
305{
306	struct proc *p;
307
308	p = td->td_proc;
309
310	/* Signal userland that it can free the stack. */
311	if ((void *)uap->state != NULL) {
312		suword_lwpid(uap->state, 1);
313		kern_umtx_wake(td, uap->state, INT_MAX, 0);
314	}
315
316	rw_wlock(&tidhash_lock);
317
318	PROC_LOCK(p);
319
320	if (p->p_numthreads != 1) {
321		racct_sub(p, RACCT_NTHR, 1);
322		LIST_REMOVE(td, td_hash);
323		rw_wunlock(&tidhash_lock);
324		tdsigcleanup(td);
325		umtx_thread_exit(td);
326		PROC_SLOCK(p);
327		thread_stopped(p);
328		thread_exit();
329		/* NOTREACHED */
330	}
331
332	/*
333	 * Ignore attempts to shut down last thread in the proc.  This
334	 * will actually call _exit(2) in the usermode trampoline when
335	 * it returns.
336	 */
337	PROC_UNLOCK(p);
338	rw_wunlock(&tidhash_lock);
339	return (0);
340}
341
342int
343sys_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
389int
390sys_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
446int
447sys_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
464int
465kern_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
508int
509sys_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
532int
533sys_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}
559