kern_thr.c revision 289780 
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 289780 2015-10-23 01:27:44Z jhb $");
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	newtd->td_dbg_sc_code = td->td_dbg_sc_code;
244	newtd->td_dbg_sc_narg = td->td_dbg_sc_narg;
245
246	error = initialize_thread(newtd, thunk);
247	if (error != 0) {
248		thread_free(newtd);
249		crfree(td->td_ucred);
250		goto fail;
251	}
252
253	PROC_LOCK(td->td_proc);
254	td->td_proc->p_flag |= P_HADTHREADS;
255	thread_link(newtd, p);
256	bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
257	thread_lock(td);
258	/* let the scheduler know about these things. */
259	sched_fork_thread(td, newtd);
260	thread_unlock(td);
261	if (P_SHOULDSTOP(p))
262		newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
263	PROC_UNLOCK(p);
264
265	tidhash_add(newtd);
266
267	thread_lock(newtd);
268	if (rtp != NULL) {
269		if (!(td->td_pri_class == PRI_TIMESHARE &&
270		      rtp->type == RTP_PRIO_NORMAL)) {
271			rtp_to_pri(rtp, newtd);
272			sched_prio(newtd, newtd->td_user_pri);
273		} /* ignore timesharing class */
274	}
275	TD_SET_CAN_RUN(newtd);
276	sched_add(newtd, SRQ_BORING);
277	thread_unlock(newtd);
278
279	return (0);
280
281fail:
282#ifdef RACCT
283	if (racct_enable) {
284		PROC_LOCK(p);
285		racct_sub(p, RACCT_NTHR, 1);
286		PROC_UNLOCK(p);
287	}
288#endif
289	return (error);
290}
291
292int
293sys_thr_self(struct thread *td, struct thr_self_args *uap)
294    /* long *id */
295{
296	int error;
297
298	error = suword_lwpid(uap->id, (unsigned)td->td_tid);
299	if (error == -1)
300		return (EFAULT);
301	return (0);
302}
303
304int
305sys_thr_exit(struct thread *td, struct thr_exit_args *uap)
306    /* long *state */
307{
308	struct proc *p;
309
310	p = td->td_proc;
311
312	/* Signal userland that it can free the stack. */
313	if ((void *)uap->state != NULL) {
314		suword_lwpid(uap->state, 1);
315		kern_umtx_wake(td, uap->state, INT_MAX, 0);
316	}
317
318	rw_wlock(&tidhash_lock);
319
320	PROC_LOCK(p);
321
322	if (p->p_numthreads != 1) {
323		racct_sub(p, RACCT_NTHR, 1);
324		LIST_REMOVE(td, td_hash);
325		rw_wunlock(&tidhash_lock);
326		tdsigcleanup(td);
327		umtx_thread_exit(td);
328		PROC_SLOCK(p);
329		thread_stopped(p);
330		thread_exit();
331		/* NOTREACHED */
332	}
333
334	/*
335	 * Ignore attempts to shut down last thread in the proc.  This
336	 * will actually call _exit(2) in the usermode trampoline when
337	 * it returns.
338	 */
339	PROC_UNLOCK(p);
340	rw_wunlock(&tidhash_lock);
341	return (0);
342}
343
344int
345sys_thr_kill(struct thread *td, struct thr_kill_args *uap)
346    /* long id, int sig */
347{
348	ksiginfo_t ksi;
349	struct thread *ttd;
350	struct proc *p;
351	int error;
352
353	p = td->td_proc;
354	ksiginfo_init(&ksi);
355	ksi.ksi_signo = uap->sig;
356	ksi.ksi_code = SI_LWP;
357	ksi.ksi_pid = p->p_pid;
358	ksi.ksi_uid = td->td_ucred->cr_ruid;
359	if (uap->id == -1) {
360		if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
361			error = EINVAL;
362		} else {
363			error = ESRCH;
364			PROC_LOCK(p);
365			FOREACH_THREAD_IN_PROC(p, ttd) {
366				if (ttd != td) {
367					error = 0;
368					if (uap->sig == 0)
369						break;
370					tdksignal(ttd, uap->sig, &ksi);
371				}
372			}
373			PROC_UNLOCK(p);
374		}
375	} else {
376		error = 0;
377		ttd = tdfind((lwpid_t)uap->id, p->p_pid);
378		if (ttd == NULL)
379			return (ESRCH);
380		if (uap->sig == 0)
381			;
382		else if (!_SIG_VALID(uap->sig))
383			error = EINVAL;
384		else
385			tdksignal(ttd, uap->sig, &ksi);
386		PROC_UNLOCK(ttd->td_proc);
387	}
388	return (error);
389}
390
391int
392sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap)
393    /* pid_t pid, long id, int sig */
394{
395	ksiginfo_t ksi;
396	struct thread *ttd;
397	struct proc *p;
398	int error;
399
400	AUDIT_ARG_SIGNUM(uap->sig);
401
402	ksiginfo_init(&ksi);
403	ksi.ksi_signo = uap->sig;
404	ksi.ksi_code = SI_LWP;
405	ksi.ksi_pid = td->td_proc->p_pid;
406	ksi.ksi_uid = td->td_ucred->cr_ruid;
407	if (uap->id == -1) {
408		if ((p = pfind(uap->pid)) == NULL)
409			return (ESRCH);
410		AUDIT_ARG_PROCESS(p);
411		error = p_cansignal(td, p, uap->sig);
412		if (error) {
413			PROC_UNLOCK(p);
414			return (error);
415		}
416		if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
417			error = EINVAL;
418		} else {
419			error = ESRCH;
420			FOREACH_THREAD_IN_PROC(p, ttd) {
421				if (ttd != td) {
422					error = 0;
423					if (uap->sig == 0)
424						break;
425					tdksignal(ttd, uap->sig, &ksi);
426				}
427			}
428		}
429		PROC_UNLOCK(p);
430	} else {
431		ttd = tdfind((lwpid_t)uap->id, uap->pid);
432		if (ttd == NULL)
433			return (ESRCH);
434		p = ttd->td_proc;
435		AUDIT_ARG_PROCESS(p);
436		error = p_cansignal(td, p, uap->sig);
437		if (uap->sig == 0)
438			;
439		else if (!_SIG_VALID(uap->sig))
440			error = EINVAL;
441		else
442			tdksignal(ttd, uap->sig, &ksi);
443		PROC_UNLOCK(p);
444	}
445	return (error);
446}
447
448int
449sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap)
450	/* const struct timespec *timeout */
451{
452	struct timespec ts, *tsp;
453	int error;
454
455	tsp = NULL;
456	if (uap->timeout != NULL) {
457		error = umtx_copyin_timeout(uap->timeout, &ts);
458		if (error != 0)
459			return (error);
460		tsp = &ts;
461	}
462
463	return (kern_thr_suspend(td, tsp));
464}
465
466int
467kern_thr_suspend(struct thread *td, struct timespec *tsp)
468{
469	struct proc *p = td->td_proc;
470	struct timeval tv;
471	int error = 0;
472	int timo = 0;
473
474	if (td->td_pflags & TDP_WAKEUP) {
475		td->td_pflags &= ~TDP_WAKEUP;
476		return (0);
477	}
478
479	if (tsp != NULL) {
480		if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
481			error = EWOULDBLOCK;
482		else {
483			TIMESPEC_TO_TIMEVAL(&tv, tsp);
484			timo = tvtohz(&tv);
485		}
486	}
487
488	PROC_LOCK(p);
489	if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0)
490		error = msleep((void *)td, &p->p_mtx,
491			 PCATCH, "lthr", timo);
492
493	if (td->td_flags & TDF_THRWAKEUP) {
494		thread_lock(td);
495		td->td_flags &= ~TDF_THRWAKEUP;
496		thread_unlock(td);
497		PROC_UNLOCK(p);
498		return (0);
499	}
500	PROC_UNLOCK(p);
501	if (error == EWOULDBLOCK)
502		error = ETIMEDOUT;
503	else if (error == ERESTART) {
504		if (timo != 0)
505			error = EINTR;
506	}
507	return (error);
508}
509
510int
511sys_thr_wake(struct thread *td, struct thr_wake_args *uap)
512	/* long id */
513{
514	struct proc *p;
515	struct thread *ttd;
516
517	if (uap->id == td->td_tid) {
518		td->td_pflags |= TDP_WAKEUP;
519		return (0);
520	}
521
522	p = td->td_proc;
523	ttd = tdfind((lwpid_t)uap->id, p->p_pid);
524	if (ttd == NULL)
525		return (ESRCH);
526	thread_lock(ttd);
527	ttd->td_flags |= TDF_THRWAKEUP;
528	thread_unlock(ttd);
529	wakeup((void *)ttd);
530	PROC_UNLOCK(p);
531	return (0);
532}
533
534int
535sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap)
536{
537	struct proc *p;
538	char name[MAXCOMLEN + 1];
539	struct thread *ttd;
540	int error;
541
542	error = 0;
543	name[0] = '\0';
544	if (uap->name != NULL) {
545		error = copyinstr(uap->name, name, sizeof(name),
546			NULL);
547		if (error)
548			return (error);
549	}
550	p = td->td_proc;
551	ttd = tdfind((lwpid_t)uap->id, p->p_pid);
552	if (ttd == NULL)
553		return (ESRCH);
554	strcpy(ttd->td_name, name);
555#ifdef KTR
556	sched_clear_tdname(ttd);
557#endif
558	PROC_UNLOCK(p);
559	return (error);
560}
561