1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/sysproto.h>
40 #include <sys/file.h>
41 #include <sys/kernel.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/mutex.h>
45 #include <sys/priv.h>
46 #include <sys/proc.h>
47 #include <sys/refcount.h>
48 #include <sys/racct.h>
49 #include <sys/resourcevar.h>
50 #include <sys/rwlock.h>
51 #include <sys/sched.h>
52 #include <sys/sx.h>
53 #include <sys/syscallsubr.h>
54 #include <sys/sysctl.h>
55 #include <sys/sysent.h>
56 #include <sys/time.h>
57 #include <sys/umtxvar.h>
58
59 #include <vm/vm.h>
60 #include <vm/vm_param.h>
61 #include <vm/pmap.h>
62 #include <vm/vm_map.h>
63
64 static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
65 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
66 #define UIHASH(uid) (&uihashtbl[(uid) & uihash])
67 static struct rwlock uihashtbl_lock;
68 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
69 static u_long uihash; /* size of hash table - 1 */
70
71 static void calcru1(struct proc *p, struct rusage_ext *ruxp,
72 struct timeval *up, struct timeval *sp);
73 static int donice(struct thread *td, struct proc *chgp, int n);
74 static struct uidinfo *uilookup(uid_t uid);
75 static void ruxagg_ext_locked(struct rusage_ext *rux, struct thread *td);
76
77 /*
78 * Resource controls and accounting.
79 */
80 #ifndef _SYS_SYSPROTO_H_
81 struct getpriority_args {
82 int which;
83 int who;
84 };
85 #endif
86 int
sys_getpriority(struct thread * td,struct getpriority_args * uap)87 sys_getpriority(struct thread *td, struct getpriority_args *uap)
88 {
89
90 return (kern_getpriority(td, uap->which, uap->who));
91 }
92
93 int
kern_getpriority(struct thread * td,int which,int who)94 kern_getpriority(struct thread *td, int which, int who)
95 {
96 struct proc *p;
97 struct pgrp *pg;
98 int error, low;
99
100 error = 0;
101 low = PRIO_MAX + 1;
102 switch (which) {
103 case PRIO_PROCESS:
104 if (who == 0)
105 low = td->td_proc->p_nice;
106 else {
107 p = pfind(who);
108 if (p == NULL)
109 break;
110 if (p_cansee(td, p) == 0)
111 low = p->p_nice;
112 PROC_UNLOCK(p);
113 }
114 break;
115
116 case PRIO_PGRP:
117 sx_slock(&proctree_lock);
118 if (who == 0) {
119 pg = td->td_proc->p_pgrp;
120 PGRP_LOCK(pg);
121 } else {
122 pg = pgfind(who);
123 if (pg == NULL) {
124 sx_sunlock(&proctree_lock);
125 break;
126 }
127 }
128 sx_sunlock(&proctree_lock);
129 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
130 PROC_LOCK(p);
131 if (p->p_state == PRS_NORMAL &&
132 p_cansee(td, p) == 0) {
133 if (p->p_nice < low)
134 low = p->p_nice;
135 }
136 PROC_UNLOCK(p);
137 }
138 PGRP_UNLOCK(pg);
139 break;
140
141 case PRIO_USER:
142 if (who == 0)
143 who = td->td_ucred->cr_uid;
144 sx_slock(&allproc_lock);
145 FOREACH_PROC_IN_SYSTEM(p) {
146 PROC_LOCK(p);
147 if (p->p_state == PRS_NORMAL &&
148 p_cansee(td, p) == 0 &&
149 p->p_ucred->cr_uid == who) {
150 if (p->p_nice < low)
151 low = p->p_nice;
152 }
153 PROC_UNLOCK(p);
154 }
155 sx_sunlock(&allproc_lock);
156 break;
157
158 default:
159 error = EINVAL;
160 break;
161 }
162 if (low == PRIO_MAX + 1 && error == 0)
163 error = ESRCH;
164 td->td_retval[0] = low;
165 return (error);
166 }
167
168 #ifndef _SYS_SYSPROTO_H_
169 struct setpriority_args {
170 int which;
171 int who;
172 int prio;
173 };
174 #endif
175 int
sys_setpriority(struct thread * td,struct setpriority_args * uap)176 sys_setpriority(struct thread *td, struct setpriority_args *uap)
177 {
178
179 return (kern_setpriority(td, uap->which, uap->who, uap->prio));
180 }
181
182 int
kern_setpriority(struct thread * td,int which,int who,int prio)183 kern_setpriority(struct thread *td, int which, int who, int prio)
184 {
185 struct proc *curp, *p;
186 struct pgrp *pg;
187 int found = 0, error = 0;
188
189 curp = td->td_proc;
190 switch (which) {
191 case PRIO_PROCESS:
192 if (who == 0) {
193 PROC_LOCK(curp);
194 error = donice(td, curp, prio);
195 PROC_UNLOCK(curp);
196 } else {
197 p = pfind(who);
198 if (p == NULL)
199 break;
200 error = p_cansee(td, p);
201 if (error == 0)
202 error = donice(td, p, prio);
203 PROC_UNLOCK(p);
204 }
205 found++;
206 break;
207
208 case PRIO_PGRP:
209 sx_slock(&proctree_lock);
210 if (who == 0) {
211 pg = curp->p_pgrp;
212 PGRP_LOCK(pg);
213 } else {
214 pg = pgfind(who);
215 if (pg == NULL) {
216 sx_sunlock(&proctree_lock);
217 break;
218 }
219 }
220 sx_sunlock(&proctree_lock);
221 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
222 PROC_LOCK(p);
223 if (p->p_state == PRS_NORMAL &&
224 p_cansee(td, p) == 0) {
225 error = donice(td, p, prio);
226 found++;
227 }
228 PROC_UNLOCK(p);
229 }
230 PGRP_UNLOCK(pg);
231 break;
232
233 case PRIO_USER:
234 if (who == 0)
235 who = td->td_ucred->cr_uid;
236 sx_slock(&allproc_lock);
237 FOREACH_PROC_IN_SYSTEM(p) {
238 PROC_LOCK(p);
239 if (p->p_state == PRS_NORMAL &&
240 p->p_ucred->cr_uid == who &&
241 p_cansee(td, p) == 0) {
242 error = donice(td, p, prio);
243 found++;
244 }
245 PROC_UNLOCK(p);
246 }
247 sx_sunlock(&allproc_lock);
248 break;
249
250 default:
251 error = EINVAL;
252 break;
253 }
254 if (found == 0 && error == 0)
255 error = ESRCH;
256 return (error);
257 }
258
259 /*
260 * Set "nice" for a (whole) process.
261 */
262 static int
donice(struct thread * td,struct proc * p,int n)263 donice(struct thread *td, struct proc *p, int n)
264 {
265 int error;
266
267 PROC_LOCK_ASSERT(p, MA_OWNED);
268 if ((error = p_cansched(td, p)))
269 return (error);
270 if (n > PRIO_MAX)
271 n = PRIO_MAX;
272 if (n < PRIO_MIN)
273 n = PRIO_MIN;
274 if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
275 return (EACCES);
276 sched_nice(p, n);
277 return (0);
278 }
279
280 static int unprivileged_idprio;
281 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
282 &unprivileged_idprio, 0,
283 "Allow non-root users to set an idle priority (deprecated)");
284
285 /*
286 * Set realtime priority for LWP.
287 */
288 #ifndef _SYS_SYSPROTO_H_
289 struct rtprio_thread_args {
290 int function;
291 lwpid_t lwpid;
292 struct rtprio *rtp;
293 };
294 #endif
295 int
sys_rtprio_thread(struct thread * td,struct rtprio_thread_args * uap)296 sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
297 {
298 struct proc *p;
299 struct rtprio rtp;
300 struct thread *td1;
301 int cierror, error;
302
303 /* Perform copyin before acquiring locks if needed. */
304 if (uap->function == RTP_SET)
305 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
306 else
307 cierror = 0;
308
309 if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
310 p = td->td_proc;
311 td1 = td;
312 PROC_LOCK(p);
313 } else {
314 td1 = tdfind(uap->lwpid, -1);
315 if (td1 == NULL)
316 return (ESRCH);
317 p = td1->td_proc;
318 }
319
320 switch (uap->function) {
321 case RTP_LOOKUP:
322 if ((error = p_cansee(td, p)))
323 break;
324 pri_to_rtp(td1, &rtp);
325 PROC_UNLOCK(p);
326 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
327 case RTP_SET:
328 if ((error = p_cansched(td, p)) || (error = cierror))
329 break;
330
331 /* Disallow setting rtprio in most cases if not superuser. */
332
333 /*
334 * Realtime priority has to be restricted for reasons which
335 * should be obvious. However, for idleprio processes, there is
336 * a potential for system deadlock if an idleprio process gains
337 * a lock on a resource that other processes need (and the
338 * idleprio process can't run due to a CPU-bound normal
339 * process). Fix me! XXX
340 *
341 * This problem is not only related to idleprio process.
342 * A user level program can obtain a file lock and hold it
343 * indefinitely. Additionally, without idleprio processes it is
344 * still conceivable that a program with low priority will never
345 * get to run. In short, allowing this feature might make it
346 * easier to lock a resource indefinitely, but it is not the
347 * only thing that makes it possible.
348 */
349 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME &&
350 (error = priv_check(td, PRIV_SCHED_RTPRIO)) != 0)
351 break;
352 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
353 unprivileged_idprio == 0 &&
354 (error = priv_check(td, PRIV_SCHED_IDPRIO)) != 0)
355 break;
356 error = rtp_to_pri(&rtp, td1);
357 break;
358 default:
359 error = EINVAL;
360 break;
361 }
362 PROC_UNLOCK(p);
363 return (error);
364 }
365
366 /*
367 * Set realtime priority.
368 */
369 #ifndef _SYS_SYSPROTO_H_
370 struct rtprio_args {
371 int function;
372 pid_t pid;
373 struct rtprio *rtp;
374 };
375 #endif
376 int
sys_rtprio(struct thread * td,struct rtprio_args * uap)377 sys_rtprio(struct thread *td, struct rtprio_args *uap)
378 {
379 struct proc *p;
380 struct thread *tdp;
381 struct rtprio rtp;
382 int cierror, error;
383
384 /* Perform copyin before acquiring locks if needed. */
385 if (uap->function == RTP_SET)
386 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
387 else
388 cierror = 0;
389
390 if (uap->pid == 0) {
391 p = td->td_proc;
392 PROC_LOCK(p);
393 } else {
394 p = pfind(uap->pid);
395 if (p == NULL)
396 return (ESRCH);
397 }
398
399 switch (uap->function) {
400 case RTP_LOOKUP:
401 if ((error = p_cansee(td, p)))
402 break;
403 /*
404 * Return OUR priority if no pid specified,
405 * or if one is, report the highest priority
406 * in the process. There isn't much more you can do as
407 * there is only room to return a single priority.
408 * Note: specifying our own pid is not the same
409 * as leaving it zero.
410 */
411 if (uap->pid == 0) {
412 pri_to_rtp(td, &rtp);
413 } else {
414 struct rtprio rtp2;
415
416 rtp.type = RTP_PRIO_IDLE;
417 rtp.prio = RTP_PRIO_MAX;
418 FOREACH_THREAD_IN_PROC(p, tdp) {
419 pri_to_rtp(tdp, &rtp2);
420 if (rtp2.type < rtp.type ||
421 (rtp2.type == rtp.type &&
422 rtp2.prio < rtp.prio)) {
423 rtp.type = rtp2.type;
424 rtp.prio = rtp2.prio;
425 }
426 }
427 }
428 PROC_UNLOCK(p);
429 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
430 case RTP_SET:
431 if ((error = p_cansched(td, p)) || (error = cierror))
432 break;
433
434 /*
435 * Disallow setting rtprio in most cases if not superuser.
436 * See the comment in sys_rtprio_thread about idprio
437 * threads holding a lock.
438 */
439 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME &&
440 (error = priv_check(td, PRIV_SCHED_RTPRIO)) != 0)
441 break;
442 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
443 unprivileged_idprio == 0 &&
444 (error = priv_check(td, PRIV_SCHED_IDPRIO)) != 0)
445 break;
446
447 /*
448 * If we are setting our own priority, set just our
449 * thread but if we are doing another process,
450 * do all the threads on that process. If we
451 * specify our own pid we do the latter.
452 */
453 if (uap->pid == 0) {
454 error = rtp_to_pri(&rtp, td);
455 } else {
456 FOREACH_THREAD_IN_PROC(p, td) {
457 if ((error = rtp_to_pri(&rtp, td)) != 0)
458 break;
459 }
460 }
461 break;
462 default:
463 error = EINVAL;
464 break;
465 }
466 PROC_UNLOCK(p);
467 return (error);
468 }
469
470 int
rtp_to_pri(struct rtprio * rtp,struct thread * td)471 rtp_to_pri(struct rtprio *rtp, struct thread *td)
472 {
473 u_char newpri, oldclass, oldpri;
474
475 switch (RTP_PRIO_BASE(rtp->type)) {
476 case RTP_PRIO_REALTIME:
477 if (rtp->prio > RTP_PRIO_MAX)
478 return (EINVAL);
479 newpri = PRI_MIN_REALTIME + rtp->prio;
480 break;
481 case RTP_PRIO_NORMAL:
482 if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
483 return (EINVAL);
484 newpri = PRI_MIN_TIMESHARE + rtp->prio;
485 break;
486 case RTP_PRIO_IDLE:
487 if (rtp->prio > RTP_PRIO_MAX)
488 return (EINVAL);
489 newpri = PRI_MIN_IDLE + rtp->prio;
490 break;
491 default:
492 return (EINVAL);
493 }
494
495 thread_lock(td);
496 oldclass = td->td_pri_class;
497 sched_class(td, rtp->type); /* XXX fix */
498 oldpri = td->td_user_pri;
499 sched_user_prio(td, newpri);
500 if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL ||
501 td->td_pri_class != RTP_PRIO_NORMAL))
502 sched_prio(td, td->td_user_pri);
503 if (TD_ON_UPILOCK(td) && oldpri != newpri) {
504 critical_enter();
505 thread_unlock(td);
506 umtx_pi_adjust(td, oldpri);
507 critical_exit();
508 } else
509 thread_unlock(td);
510 return (0);
511 }
512
513 void
pri_to_rtp(struct thread * td,struct rtprio * rtp)514 pri_to_rtp(struct thread *td, struct rtprio *rtp)
515 {
516
517 thread_lock(td);
518 switch (PRI_BASE(td->td_pri_class)) {
519 case PRI_REALTIME:
520 rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
521 break;
522 case PRI_TIMESHARE:
523 rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
524 break;
525 case PRI_IDLE:
526 rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
527 break;
528 default:
529 break;
530 }
531 rtp->type = td->td_pri_class;
532 thread_unlock(td);
533 }
534
535 #if defined(COMPAT_43)
536 #ifndef _SYS_SYSPROTO_H_
537 struct osetrlimit_args {
538 u_int which;
539 struct orlimit *rlp;
540 };
541 #endif
542 int
osetrlimit(struct thread * td,struct osetrlimit_args * uap)543 osetrlimit(struct thread *td, struct osetrlimit_args *uap)
544 {
545 struct orlimit olim;
546 struct rlimit lim;
547 int error;
548
549 if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
550 return (error);
551 lim.rlim_cur = olim.rlim_cur;
552 lim.rlim_max = olim.rlim_max;
553 error = kern_setrlimit(td, uap->which, &lim);
554 return (error);
555 }
556
557 #ifndef _SYS_SYSPROTO_H_
558 struct ogetrlimit_args {
559 u_int which;
560 struct orlimit *rlp;
561 };
562 #endif
563 int
ogetrlimit(struct thread * td,struct ogetrlimit_args * uap)564 ogetrlimit(struct thread *td, struct ogetrlimit_args *uap)
565 {
566 struct orlimit olim;
567 struct rlimit rl;
568 int error;
569
570 if (uap->which >= RLIM_NLIMITS)
571 return (EINVAL);
572 lim_rlimit(td, uap->which, &rl);
573
574 /*
575 * XXX would be more correct to convert only RLIM_INFINITY to the
576 * old RLIM_INFINITY and fail with EOVERFLOW for other larger
577 * values. Most 64->32 and 32->16 conversions, including not
578 * unimportant ones of uids are even more broken than what we
579 * do here (they blindly truncate). We don't do this correctly
580 * here since we have little experience with EOVERFLOW yet.
581 * Elsewhere, getuid() can't fail...
582 */
583 olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
584 olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
585 error = copyout(&olim, uap->rlp, sizeof(olim));
586 return (error);
587 }
588 #endif /* COMPAT_43 */
589
590 #ifndef _SYS_SYSPROTO_H_
591 struct setrlimit_args {
592 u_int which;
593 struct rlimit *rlp;
594 };
595 #endif
596 int
sys_setrlimit(struct thread * td,struct setrlimit_args * uap)597 sys_setrlimit(struct thread *td, struct setrlimit_args *uap)
598 {
599 struct rlimit alim;
600 int error;
601
602 if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
603 return (error);
604 error = kern_setrlimit(td, uap->which, &alim);
605 return (error);
606 }
607
608 static void
lim_cb(void * arg)609 lim_cb(void *arg)
610 {
611 struct rlimit rlim;
612 struct thread *td;
613 struct proc *p;
614
615 p = arg;
616 PROC_LOCK_ASSERT(p, MA_OWNED);
617 /*
618 * Check if the process exceeds its cpu resource allocation. If
619 * it reaches the max, arrange to kill the process in ast().
620 */
621 if (p->p_cpulimit == RLIM_INFINITY)
622 return;
623 PROC_STATLOCK(p);
624 FOREACH_THREAD_IN_PROC(p, td) {
625 ruxagg(p, td);
626 }
627 PROC_STATUNLOCK(p);
628 if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
629 lim_rlimit_proc(p, RLIMIT_CPU, &rlim);
630 if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
631 killproc(p, "exceeded maximum CPU limit");
632 } else {
633 if (p->p_cpulimit < rlim.rlim_max)
634 p->p_cpulimit += 5;
635 kern_psignal(p, SIGXCPU);
636 }
637 }
638 if ((p->p_flag & P_WEXIT) == 0)
639 callout_reset_sbt(&p->p_limco, SBT_1S, 0,
640 lim_cb, p, C_PREL(1));
641 }
642
643 int
kern_setrlimit(struct thread * td,u_int which,struct rlimit * limp)644 kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
645 {
646
647 return (kern_proc_setrlimit(td, td->td_proc, which, limp));
648 }
649
650 int
kern_proc_setrlimit(struct thread * td,struct proc * p,u_int which,struct rlimit * limp)651 kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
652 struct rlimit *limp)
653 {
654 struct plimit *newlim, *oldlim, *oldlim_td;
655 struct rlimit *alimp;
656 struct rlimit oldssiz;
657 int error;
658
659 if (which >= RLIM_NLIMITS)
660 return (EINVAL);
661
662 /*
663 * Preserve historical bugs by treating negative limits as unsigned.
664 */
665 if (limp->rlim_cur < 0)
666 limp->rlim_cur = RLIM_INFINITY;
667 if (limp->rlim_max < 0)
668 limp->rlim_max = RLIM_INFINITY;
669
670 oldssiz.rlim_cur = 0;
671 newlim = lim_alloc();
672 PROC_LOCK(p);
673 oldlim = p->p_limit;
674 alimp = &oldlim->pl_rlimit[which];
675 if (limp->rlim_cur > alimp->rlim_max ||
676 limp->rlim_max > alimp->rlim_max)
677 if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
678 PROC_UNLOCK(p);
679 lim_free(newlim);
680 return (error);
681 }
682 if (limp->rlim_cur > limp->rlim_max)
683 limp->rlim_cur = limp->rlim_max;
684 lim_copy(newlim, oldlim);
685 alimp = &newlim->pl_rlimit[which];
686
687 switch (which) {
688 case RLIMIT_CPU:
689 if (limp->rlim_cur != RLIM_INFINITY &&
690 p->p_cpulimit == RLIM_INFINITY)
691 callout_reset_sbt(&p->p_limco, SBT_1S, 0,
692 lim_cb, p, C_PREL(1));
693 p->p_cpulimit = limp->rlim_cur;
694 break;
695 case RLIMIT_DATA:
696 if (limp->rlim_cur > maxdsiz)
697 limp->rlim_cur = maxdsiz;
698 if (limp->rlim_max > maxdsiz)
699 limp->rlim_max = maxdsiz;
700 break;
701
702 case RLIMIT_STACK:
703 if (limp->rlim_cur > maxssiz)
704 limp->rlim_cur = maxssiz;
705 if (limp->rlim_max > maxssiz)
706 limp->rlim_max = maxssiz;
707 oldssiz = *alimp;
708 if (p->p_sysent->sv_fixlimit != NULL)
709 p->p_sysent->sv_fixlimit(&oldssiz,
710 RLIMIT_STACK);
711 break;
712
713 case RLIMIT_NOFILE:
714 if (limp->rlim_cur > maxfilesperproc)
715 limp->rlim_cur = maxfilesperproc;
716 if (limp->rlim_max > maxfilesperproc)
717 limp->rlim_max = maxfilesperproc;
718 break;
719
720 case RLIMIT_NPROC:
721 if (limp->rlim_cur > maxprocperuid)
722 limp->rlim_cur = maxprocperuid;
723 if (limp->rlim_max > maxprocperuid)
724 limp->rlim_max = maxprocperuid;
725 if (limp->rlim_cur < 1)
726 limp->rlim_cur = 1;
727 if (limp->rlim_max < 1)
728 limp->rlim_max = 1;
729 break;
730 }
731 if (p->p_sysent->sv_fixlimit != NULL)
732 p->p_sysent->sv_fixlimit(limp, which);
733 *alimp = *limp;
734 p->p_limit = newlim;
735 PROC_UPDATE_COW(p);
736 oldlim_td = NULL;
737 if (td == curthread && PROC_COW_CHANGECOUNT(td, p) == 1) {
738 oldlim_td = lim_cowsync();
739 thread_cow_synced(td);
740 }
741 PROC_UNLOCK(p);
742 if (oldlim_td != NULL) {
743 MPASS(oldlim_td == oldlim);
744 lim_freen(oldlim, 2);
745 } else {
746 lim_free(oldlim);
747 }
748
749 if (which == RLIMIT_STACK &&
750 /*
751 * Skip calls from exec_new_vmspace(), done when stack is
752 * not mapped yet.
753 */
754 (td != curthread || (p->p_flag & P_INEXEC) == 0)) {
755 /*
756 * Stack is allocated to the max at exec time with only
757 * "rlim_cur" bytes accessible. If stack limit is going
758 * up make more accessible, if going down make inaccessible.
759 */
760 if (limp->rlim_cur != oldssiz.rlim_cur) {
761 vm_offset_t addr;
762 vm_size_t size;
763 vm_prot_t prot;
764
765 if (limp->rlim_cur > oldssiz.rlim_cur) {
766 prot = p->p_sysent->sv_stackprot;
767 size = limp->rlim_cur - oldssiz.rlim_cur;
768 addr = round_page(p->p_vmspace->vm_stacktop) -
769 limp->rlim_cur;
770 } else {
771 prot = VM_PROT_NONE;
772 size = oldssiz.rlim_cur - limp->rlim_cur;
773 addr = round_page(p->p_vmspace->vm_stacktop) -
774 oldssiz.rlim_cur;
775 }
776 addr = trunc_page(addr);
777 size = round_page(size);
778 (void)vm_map_protect(&p->p_vmspace->vm_map,
779 addr, addr + size, prot, 0,
780 VM_MAP_PROTECT_SET_PROT);
781 }
782 }
783
784 return (0);
785 }
786
787 #ifndef _SYS_SYSPROTO_H_
788 struct getrlimit_args {
789 u_int which;
790 struct rlimit *rlp;
791 };
792 #endif
793 /* ARGSUSED */
794 int
sys_getrlimit(struct thread * td,struct getrlimit_args * uap)795 sys_getrlimit(struct thread *td, struct getrlimit_args *uap)
796 {
797 struct rlimit rlim;
798 int error;
799
800 if (uap->which >= RLIM_NLIMITS)
801 return (EINVAL);
802 lim_rlimit(td, uap->which, &rlim);
803 error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
804 return (error);
805 }
806
807 /*
808 * Transform the running time and tick information for children of proc p
809 * into user and system time usage.
810 */
811 void
calccru(struct proc * p,struct timeval * up,struct timeval * sp)812 calccru(struct proc *p, struct timeval *up, struct timeval *sp)
813 {
814
815 PROC_LOCK_ASSERT(p, MA_OWNED);
816 calcru1(p, &p->p_crux, up, sp);
817 }
818
819 /*
820 * Transform the running time and tick information in proc p into user
821 * and system time usage. If appropriate, include the current time slice
822 * on this CPU.
823 */
824 void
calcru(struct proc * p,struct timeval * up,struct timeval * sp)825 calcru(struct proc *p, struct timeval *up, struct timeval *sp)
826 {
827 struct thread *td;
828 uint64_t runtime, u;
829
830 PROC_LOCK_ASSERT(p, MA_OWNED);
831 PROC_STATLOCK_ASSERT(p, MA_OWNED);
832 /*
833 * If we are getting stats for the current process, then add in the
834 * stats that this thread has accumulated in its current time slice.
835 * We reset the thread and CPU state as if we had performed a context
836 * switch right here.
837 */
838 td = curthread;
839 if (td->td_proc == p) {
840 u = cpu_ticks();
841 runtime = u - PCPU_GET(switchtime);
842 td->td_runtime += runtime;
843 td->td_incruntime += runtime;
844 PCPU_SET(switchtime, u);
845 }
846 /* Make sure the per-thread stats are current. */
847 FOREACH_THREAD_IN_PROC(p, td) {
848 if (td->td_incruntime == 0)
849 continue;
850 ruxagg(p, td);
851 }
852 calcru1(p, &p->p_rux, up, sp);
853 }
854
855 /* Collect resource usage for a single thread. */
856 void
rufetchtd(struct thread * td,struct rusage * ru)857 rufetchtd(struct thread *td, struct rusage *ru)
858 {
859 struct proc *p;
860 uint64_t runtime, u;
861
862 p = td->td_proc;
863 PROC_STATLOCK_ASSERT(p, MA_OWNED);
864 THREAD_LOCK_ASSERT(td, MA_OWNED);
865 /*
866 * If we are getting stats for the current thread, then add in the
867 * stats that this thread has accumulated in its current time slice.
868 * We reset the thread and CPU state as if we had performed a context
869 * switch right here.
870 */
871 if (td == curthread) {
872 u = cpu_ticks();
873 runtime = u - PCPU_GET(switchtime);
874 td->td_runtime += runtime;
875 td->td_incruntime += runtime;
876 PCPU_SET(switchtime, u);
877 }
878 ruxagg_locked(p, td);
879 *ru = td->td_ru;
880 calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
881 }
882
883 static uint64_t
mul64_by_fraction(uint64_t a,uint64_t b,uint64_t c)884 mul64_by_fraction(uint64_t a, uint64_t b, uint64_t c)
885 {
886 uint64_t acc, bh, bl;
887 int i, s, sa, sb;
888
889 /*
890 * Calculate (a * b) / c accurately enough without overflowing. c
891 * must be nonzero, and its top bit must be 0. a or b must be
892 * <= c, and the implementation is tuned for b <= c.
893 *
894 * The comments about times are for use in calcru1() with units of
895 * microseconds for 'a' and stathz ticks at 128 Hz for b and c.
896 *
897 * Let n be the number of top zero bits in c. Each iteration
898 * either returns, or reduces b by right shifting it by at least n.
899 * The number of iterations is at most 1 + 64 / n, and the error is
900 * at most the number of iterations.
901 *
902 * It is very unusual to need even 2 iterations. Previous
903 * implementations overflowed essentially by returning early in the
904 * first iteration, with n = 38 giving overflow at 105+ hours and
905 * n = 32 giving overlow at at 388+ days despite a more careful
906 * calculation. 388 days is a reasonable uptime, and the calculation
907 * needs to work for the uptime times the number of CPUs since 'a'
908 * is per-process.
909 */
910 if (a >= (uint64_t)1 << 63)
911 return (0); /* Unsupported arg -- can't happen. */
912 acc = 0;
913 for (i = 0; i < 128; i++) {
914 sa = flsll(a);
915 sb = flsll(b);
916 if (sa + sb <= 64)
917 /* Up to 105 hours on first iteration. */
918 return (acc + (a * b) / c);
919 if (a >= c) {
920 /*
921 * This reduction is based on a = q * c + r, with the
922 * remainder r < c. 'a' may be large to start, and
923 * moving bits from b into 'a' at the end of the loop
924 * sets the top bit of 'a', so the reduction makes
925 * significant progress.
926 */
927 acc += (a / c) * b;
928 a %= c;
929 sa = flsll(a);
930 if (sa + sb <= 64)
931 /* Up to 388 days on first iteration. */
932 return (acc + (a * b) / c);
933 }
934
935 /*
936 * This step writes a * b as a * ((bh << s) + bl) =
937 * a * (bh << s) + a * bl = (a << s) * bh + a * bl. The 2
938 * additive terms are handled separately. Splitting in
939 * this way is linear except for rounding errors.
940 *
941 * s = 64 - sa is the maximum such that a << s fits in 64
942 * bits. Since a < c and c has at least 1 zero top bit,
943 * sa < 64 and s > 0. Thus this step makes progress by
944 * reducing b (it increases 'a', but taking remainders on
945 * the next iteration completes the reduction).
946 *
947 * Finally, the choice for s is just what is needed to keep
948 * a * bl from overflowing, so we don't need complications
949 * like a recursive call mul64_by_fraction(a, bl, c) to
950 * handle the second additive term.
951 */
952 s = 64 - sa;
953 bh = b >> s;
954 bl = b - (bh << s);
955 acc += (a * bl) / c;
956 a <<= s;
957 b = bh;
958 }
959 return (0); /* Algorithm failure -- can't happen. */
960 }
961
962 static void
calcru1(struct proc * p,struct rusage_ext * ruxp,struct timeval * up,struct timeval * sp)963 calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
964 struct timeval *sp)
965 {
966 /* {user, system, interrupt, total} {ticks, usec}: */
967 uint64_t ut, uu, st, su, it, tt, tu;
968
969 ut = ruxp->rux_uticks;
970 st = ruxp->rux_sticks;
971 it = ruxp->rux_iticks;
972 tt = ut + st + it;
973 if (tt == 0) {
974 /* Avoid divide by zero */
975 st = 1;
976 tt = 1;
977 }
978 tu = cputick2usec(ruxp->rux_runtime);
979 if ((int64_t)tu < 0) {
980 /* XXX: this should be an assert /phk */
981 printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
982 (intmax_t)tu, p->p_pid, p->p_comm);
983 tu = ruxp->rux_tu;
984 }
985
986 /* Subdivide tu. Avoid overflow in the multiplications. */
987 if (__predict_true(tu <= ((uint64_t)1 << 38) && tt <= (1 << 26))) {
988 /* Up to 76 hours when stathz is 128. */
989 uu = (tu * ut) / tt;
990 su = (tu * st) / tt;
991 } else {
992 uu = mul64_by_fraction(tu, ut, tt);
993 su = mul64_by_fraction(tu, st, tt);
994 }
995
996 if (tu >= ruxp->rux_tu) {
997 /*
998 * The normal case, time increased.
999 * Enforce monotonicity of bucketed numbers.
1000 */
1001 if (uu < ruxp->rux_uu)
1002 uu = ruxp->rux_uu;
1003 if (su < ruxp->rux_su)
1004 su = ruxp->rux_su;
1005 } else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
1006 /*
1007 * When we calibrate the cputicker, it is not uncommon to
1008 * see the presumably fixed frequency increase slightly over
1009 * time as a result of thermal stabilization and NTP
1010 * discipline (of the reference clock). We therefore ignore
1011 * a bit of backwards slop because we expect to catch up
1012 * shortly. We use a 3 microsecond limit to catch low
1013 * counts and a 1% limit for high counts.
1014 */
1015 uu = ruxp->rux_uu;
1016 su = ruxp->rux_su;
1017 tu = ruxp->rux_tu;
1018 } else if (vm_guest == VM_GUEST_NO) { /* tu < ruxp->rux_tu */
1019 /*
1020 * What happened here was likely that a laptop, which ran at
1021 * a reduced clock frequency at boot, kicked into high gear.
1022 * The wisdom of spamming this message in that case is
1023 * dubious, but it might also be indicative of something
1024 * serious, so lets keep it and hope laptops can be made
1025 * more truthful about their CPU speed via ACPI.
1026 */
1027 printf("calcru: runtime went backwards from %ju usec "
1028 "to %ju usec for pid %d (%s)\n",
1029 (uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
1030 p->p_pid, p->p_comm);
1031 }
1032
1033 ruxp->rux_uu = uu;
1034 ruxp->rux_su = su;
1035 ruxp->rux_tu = tu;
1036
1037 up->tv_sec = uu / 1000000;
1038 up->tv_usec = uu % 1000000;
1039 sp->tv_sec = su / 1000000;
1040 sp->tv_usec = su % 1000000;
1041 }
1042
1043 #ifndef _SYS_SYSPROTO_H_
1044 struct getrusage_args {
1045 int who;
1046 struct rusage *rusage;
1047 };
1048 #endif
1049 int
sys_getrusage(struct thread * td,struct getrusage_args * uap)1050 sys_getrusage(struct thread *td, struct getrusage_args *uap)
1051 {
1052 struct rusage ru;
1053 int error;
1054
1055 error = kern_getrusage(td, uap->who, &ru);
1056 if (error == 0)
1057 error = copyout(&ru, uap->rusage, sizeof(struct rusage));
1058 return (error);
1059 }
1060
1061 int
kern_getrusage(struct thread * td,int who,struct rusage * rup)1062 kern_getrusage(struct thread *td, int who, struct rusage *rup)
1063 {
1064 struct proc *p;
1065 int error;
1066
1067 error = 0;
1068 p = td->td_proc;
1069 PROC_LOCK(p);
1070 switch (who) {
1071 case RUSAGE_SELF:
1072 rufetchcalc(p, rup, &rup->ru_utime,
1073 &rup->ru_stime);
1074 break;
1075
1076 case RUSAGE_CHILDREN:
1077 *rup = p->p_stats->p_cru;
1078 calccru(p, &rup->ru_utime, &rup->ru_stime);
1079 break;
1080
1081 case RUSAGE_THREAD:
1082 PROC_STATLOCK(p);
1083 thread_lock(td);
1084 rufetchtd(td, rup);
1085 thread_unlock(td);
1086 PROC_STATUNLOCK(p);
1087 break;
1088
1089 default:
1090 error = EINVAL;
1091 }
1092 PROC_UNLOCK(p);
1093 return (error);
1094 }
1095
1096 void
rucollect(struct rusage * ru,struct rusage * ru2)1097 rucollect(struct rusage *ru, struct rusage *ru2)
1098 {
1099 long *ip, *ip2;
1100 int i;
1101
1102 if (ru->ru_maxrss < ru2->ru_maxrss)
1103 ru->ru_maxrss = ru2->ru_maxrss;
1104 ip = &ru->ru_first;
1105 ip2 = &ru2->ru_first;
1106 for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
1107 *ip++ += *ip2++;
1108 }
1109
1110 void
ruadd(struct rusage * ru,struct rusage_ext * rux,struct rusage * ru2,struct rusage_ext * rux2)1111 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
1112 struct rusage_ext *rux2)
1113 {
1114
1115 rux->rux_runtime += rux2->rux_runtime;
1116 rux->rux_uticks += rux2->rux_uticks;
1117 rux->rux_sticks += rux2->rux_sticks;
1118 rux->rux_iticks += rux2->rux_iticks;
1119 rux->rux_uu += rux2->rux_uu;
1120 rux->rux_su += rux2->rux_su;
1121 rux->rux_tu += rux2->rux_tu;
1122 rucollect(ru, ru2);
1123 }
1124
1125 /*
1126 * Aggregate tick counts into the proc's rusage_ext.
1127 */
1128 static void
ruxagg_ext_locked(struct rusage_ext * rux,struct thread * td)1129 ruxagg_ext_locked(struct rusage_ext *rux, struct thread *td)
1130 {
1131
1132 rux->rux_runtime += td->td_incruntime;
1133 rux->rux_uticks += td->td_uticks;
1134 rux->rux_sticks += td->td_sticks;
1135 rux->rux_iticks += td->td_iticks;
1136 }
1137
1138 void
ruxagg_locked(struct proc * p,struct thread * td)1139 ruxagg_locked(struct proc *p, struct thread *td)
1140 {
1141 THREAD_LOCK_ASSERT(td, MA_OWNED);
1142 PROC_STATLOCK_ASSERT(td->td_proc, MA_OWNED);
1143
1144 ruxagg_ext_locked(&p->p_rux, td);
1145 ruxagg_ext_locked(&td->td_rux, td);
1146 td->td_incruntime = 0;
1147 td->td_uticks = 0;
1148 td->td_iticks = 0;
1149 td->td_sticks = 0;
1150 }
1151
1152 void
ruxagg(struct proc * p,struct thread * td)1153 ruxagg(struct proc *p, struct thread *td)
1154 {
1155
1156 thread_lock(td);
1157 ruxagg_locked(p, td);
1158 thread_unlock(td);
1159 }
1160
1161 /*
1162 * Update the rusage_ext structure and fetch a valid aggregate rusage
1163 * for proc p if storage for one is supplied.
1164 */
1165 void
rufetch(struct proc * p,struct rusage * ru)1166 rufetch(struct proc *p, struct rusage *ru)
1167 {
1168 struct thread *td;
1169
1170 PROC_STATLOCK_ASSERT(p, MA_OWNED);
1171
1172 *ru = p->p_ru;
1173 if (p->p_numthreads > 0) {
1174 FOREACH_THREAD_IN_PROC(p, td) {
1175 ruxagg(p, td);
1176 rucollect(ru, &td->td_ru);
1177 }
1178 }
1179 }
1180
1181 /*
1182 * Atomically perform a rufetch and a calcru together.
1183 * Consumers, can safely assume the calcru is executed only once
1184 * rufetch is completed.
1185 */
1186 void
rufetchcalc(struct proc * p,struct rusage * ru,struct timeval * up,struct timeval * sp)1187 rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
1188 struct timeval *sp)
1189 {
1190
1191 PROC_STATLOCK(p);
1192 rufetch(p, ru);
1193 calcru(p, up, sp);
1194 PROC_STATUNLOCK(p);
1195 }
1196
1197 /*
1198 * Allocate a new resource limits structure and initialize its
1199 * reference count and mutex pointer.
1200 */
1201 struct plimit *
lim_alloc(void)1202 lim_alloc(void)
1203 {
1204 struct plimit *limp;
1205
1206 limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
1207 refcount_init(&limp->pl_refcnt, 1);
1208 return (limp);
1209 }
1210
1211 struct plimit *
lim_hold(struct plimit * limp)1212 lim_hold(struct plimit *limp)
1213 {
1214
1215 refcount_acquire(&limp->pl_refcnt);
1216 return (limp);
1217 }
1218
1219 struct plimit *
lim_cowsync(void)1220 lim_cowsync(void)
1221 {
1222 struct thread *td;
1223 struct proc *p;
1224 struct plimit *oldlimit;
1225
1226 td = curthread;
1227 p = td->td_proc;
1228 PROC_LOCK_ASSERT(p, MA_OWNED);
1229
1230 if (td->td_limit == p->p_limit)
1231 return (NULL);
1232
1233 oldlimit = td->td_limit;
1234 td->td_limit = lim_hold(p->p_limit);
1235
1236 return (oldlimit);
1237 }
1238
1239 void
lim_fork(struct proc * p1,struct proc * p2)1240 lim_fork(struct proc *p1, struct proc *p2)
1241 {
1242
1243 PROC_LOCK_ASSERT(p1, MA_OWNED);
1244 PROC_LOCK_ASSERT(p2, MA_OWNED);
1245
1246 p2->p_limit = lim_hold(p1->p_limit);
1247 callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
1248 if (p1->p_cpulimit != RLIM_INFINITY)
1249 callout_reset_sbt(&p2->p_limco, SBT_1S, 0,
1250 lim_cb, p2, C_PREL(1));
1251 }
1252
1253 void
lim_free(struct plimit * limp)1254 lim_free(struct plimit *limp)
1255 {
1256
1257 if (refcount_release(&limp->pl_refcnt))
1258 free((void *)limp, M_PLIMIT);
1259 }
1260
1261 void
lim_freen(struct plimit * limp,int n)1262 lim_freen(struct plimit *limp, int n)
1263 {
1264
1265 if (refcount_releasen(&limp->pl_refcnt, n))
1266 free((void *)limp, M_PLIMIT);
1267 }
1268
1269 void
limbatch_add(struct limbatch * lb,struct thread * td)1270 limbatch_add(struct limbatch *lb, struct thread *td)
1271 {
1272 struct plimit *limp;
1273
1274 MPASS(td->td_limit != NULL);
1275 limp = td->td_limit;
1276
1277 if (lb->limp != limp) {
1278 if (lb->count != 0) {
1279 lim_freen(lb->limp, lb->count);
1280 lb->count = 0;
1281 }
1282 lb->limp = limp;
1283 }
1284
1285 lb->count++;
1286 }
1287
1288 void
limbatch_final(struct limbatch * lb)1289 limbatch_final(struct limbatch *lb)
1290 {
1291
1292 MPASS(lb->count != 0);
1293 lim_freen(lb->limp, lb->count);
1294 }
1295
1296 /*
1297 * Make a copy of the plimit structure.
1298 * We share these structures copy-on-write after fork.
1299 */
1300 void
lim_copy(struct plimit * dst,struct plimit * src)1301 lim_copy(struct plimit *dst, struct plimit *src)
1302 {
1303
1304 KASSERT(dst->pl_refcnt <= 1, ("lim_copy to shared limit"));
1305 bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
1306 }
1307
1308 /*
1309 * Return the hard limit for a particular system resource. The
1310 * which parameter specifies the index into the rlimit array.
1311 */
1312 rlim_t
lim_max(struct thread * td,int which)1313 lim_max(struct thread *td, int which)
1314 {
1315 struct rlimit rl;
1316
1317 lim_rlimit(td, which, &rl);
1318 return (rl.rlim_max);
1319 }
1320
1321 rlim_t
lim_max_proc(struct proc * p,int which)1322 lim_max_proc(struct proc *p, int which)
1323 {
1324 struct rlimit rl;
1325
1326 lim_rlimit_proc(p, which, &rl);
1327 return (rl.rlim_max);
1328 }
1329
1330 /*
1331 * Return the current (soft) limit for a particular system resource.
1332 * The which parameter which specifies the index into the rlimit array
1333 */
rlim_t(lim_cur)1334 rlim_t
1335 (lim_cur)(struct thread *td, int which)
1336 {
1337 struct rlimit rl;
1338
1339 lim_rlimit(td, which, &rl);
1340 return (rl.rlim_cur);
1341 }
1342
1343 rlim_t
lim_cur_proc(struct proc * p,int which)1344 lim_cur_proc(struct proc *p, int which)
1345 {
1346 struct rlimit rl;
1347
1348 lim_rlimit_proc(p, which, &rl);
1349 return (rl.rlim_cur);
1350 }
1351
1352 /*
1353 * Return a copy of the entire rlimit structure for the system limit
1354 * specified by 'which' in the rlimit structure pointed to by 'rlp'.
1355 */
1356 void
lim_rlimit(struct thread * td,int which,struct rlimit * rlp)1357 lim_rlimit(struct thread *td, int which, struct rlimit *rlp)
1358 {
1359 struct proc *p = td->td_proc;
1360
1361 MPASS(td == curthread);
1362 KASSERT(which >= 0 && which < RLIM_NLIMITS,
1363 ("request for invalid resource limit"));
1364 *rlp = td->td_limit->pl_rlimit[which];
1365 if (p->p_sysent->sv_fixlimit != NULL)
1366 p->p_sysent->sv_fixlimit(rlp, which);
1367 }
1368
1369 void
lim_rlimit_proc(struct proc * p,int which,struct rlimit * rlp)1370 lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp)
1371 {
1372
1373 PROC_LOCK_ASSERT(p, MA_OWNED);
1374 KASSERT(which >= 0 && which < RLIM_NLIMITS,
1375 ("request for invalid resource limit"));
1376 *rlp = p->p_limit->pl_rlimit[which];
1377 if (p->p_sysent->sv_fixlimit != NULL)
1378 p->p_sysent->sv_fixlimit(rlp, which);
1379 }
1380
1381 void
uihashinit(void)1382 uihashinit(void)
1383 {
1384
1385 uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
1386 rw_init(&uihashtbl_lock, "uidinfo hash");
1387 }
1388
1389 /*
1390 * Look up a uidinfo struct for the parameter uid.
1391 * uihashtbl_lock must be locked.
1392 * Increase refcount on uidinfo struct returned.
1393 */
1394 static struct uidinfo *
uilookup(uid_t uid)1395 uilookup(uid_t uid)
1396 {
1397 struct uihashhead *uipp;
1398 struct uidinfo *uip;
1399
1400 rw_assert(&uihashtbl_lock, RA_LOCKED);
1401 uipp = UIHASH(uid);
1402 LIST_FOREACH(uip, uipp, ui_hash)
1403 if (uip->ui_uid == uid) {
1404 uihold(uip);
1405 break;
1406 }
1407
1408 return (uip);
1409 }
1410
1411 /*
1412 * Find or allocate a struct uidinfo for a particular uid.
1413 * Returns with uidinfo struct referenced.
1414 * uifree() should be called on a struct uidinfo when released.
1415 */
1416 struct uidinfo *
uifind(uid_t uid)1417 uifind(uid_t uid)
1418 {
1419 struct uidinfo *new_uip, *uip;
1420 struct ucred *cred;
1421
1422 cred = curthread->td_ucred;
1423 if (cred->cr_uidinfo->ui_uid == uid) {
1424 uip = cred->cr_uidinfo;
1425 uihold(uip);
1426 return (uip);
1427 } else if (cred->cr_ruidinfo->ui_uid == uid) {
1428 uip = cred->cr_ruidinfo;
1429 uihold(uip);
1430 return (uip);
1431 }
1432
1433 rw_rlock(&uihashtbl_lock);
1434 uip = uilookup(uid);
1435 rw_runlock(&uihashtbl_lock);
1436 if (uip != NULL)
1437 return (uip);
1438
1439 new_uip = malloc(sizeof(*new_uip), M_UIDINFO, M_WAITOK | M_ZERO);
1440 racct_create(&new_uip->ui_racct);
1441 refcount_init(&new_uip->ui_ref, 1);
1442 new_uip->ui_uid = uid;
1443
1444 rw_wlock(&uihashtbl_lock);
1445 /*
1446 * There's a chance someone created our uidinfo while we
1447 * were in malloc and not holding the lock, so we have to
1448 * make sure we don't insert a duplicate uidinfo.
1449 */
1450 if ((uip = uilookup(uid)) == NULL) {
1451 LIST_INSERT_HEAD(UIHASH(uid), new_uip, ui_hash);
1452 rw_wunlock(&uihashtbl_lock);
1453 uip = new_uip;
1454 } else {
1455 rw_wunlock(&uihashtbl_lock);
1456 racct_destroy(&new_uip->ui_racct);
1457 free(new_uip, M_UIDINFO);
1458 }
1459 return (uip);
1460 }
1461
1462 /*
1463 * Place another refcount on a uidinfo struct.
1464 */
1465 void
uihold(struct uidinfo * uip)1466 uihold(struct uidinfo *uip)
1467 {
1468
1469 refcount_acquire(&uip->ui_ref);
1470 }
1471
1472 /*-
1473 * Since uidinfo structs have a long lifetime, we use an
1474 * opportunistic refcounting scheme to avoid locking the lookup hash
1475 * for each release.
1476 *
1477 * If the refcount hits 0, we need to free the structure,
1478 * which means we need to lock the hash.
1479 * Optimal case:
1480 * After locking the struct and lowering the refcount, if we find
1481 * that we don't need to free, simply unlock and return.
1482 * Suboptimal case:
1483 * If refcount lowering results in need to free, bump the count
1484 * back up, lose the lock and acquire the locks in the proper
1485 * order to try again.
1486 */
1487 void
uifree(struct uidinfo * uip)1488 uifree(struct uidinfo *uip)
1489 {
1490
1491 if (refcount_release_if_not_last(&uip->ui_ref))
1492 return;
1493
1494 rw_wlock(&uihashtbl_lock);
1495 if (refcount_release(&uip->ui_ref) == 0) {
1496 rw_wunlock(&uihashtbl_lock);
1497 return;
1498 }
1499
1500 racct_destroy(&uip->ui_racct);
1501 LIST_REMOVE(uip, ui_hash);
1502 rw_wunlock(&uihashtbl_lock);
1503
1504 if (uip->ui_sbsize != 0)
1505 printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
1506 uip->ui_uid, uip->ui_sbsize);
1507 if (uip->ui_proccnt != 0)
1508 printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
1509 uip->ui_uid, uip->ui_proccnt);
1510 if (uip->ui_vmsize != 0)
1511 printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
1512 uip->ui_uid, (unsigned long long)uip->ui_vmsize);
1513 if (uip->ui_ptscnt != 0)
1514 printf("freeing uidinfo: uid = %d, ptscnt = %ld\n",
1515 uip->ui_uid, uip->ui_ptscnt);
1516 if (uip->ui_kqcnt != 0)
1517 printf("freeing uidinfo: uid = %d, kqcnt = %ld\n",
1518 uip->ui_uid, uip->ui_kqcnt);
1519 if (uip->ui_umtxcnt != 0)
1520 printf("freeing uidinfo: uid = %d, umtxcnt = %ld\n",
1521 uip->ui_uid, uip->ui_umtxcnt);
1522 if (uip->ui_pipecnt != 0)
1523 printf("freeing uidinfo: uid = %d, pipecnt = %ld\n",
1524 uip->ui_uid, uip->ui_pipecnt);
1525 free(uip, M_UIDINFO);
1526 }
1527
1528 #ifdef RACCT
1529 void
ui_racct_foreach(void (* callback)(struct racct * racct,void * arg2,void * arg3),void (* pre)(void),void (* post)(void),void * arg2,void * arg3)1530 ui_racct_foreach(void (*callback)(struct racct *racct,
1531 void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
1532 void *arg2, void *arg3)
1533 {
1534 struct uidinfo *uip;
1535 struct uihashhead *uih;
1536
1537 rw_rlock(&uihashtbl_lock);
1538 if (pre != NULL)
1539 (pre)();
1540 for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
1541 LIST_FOREACH(uip, uih, ui_hash) {
1542 (callback)(uip->ui_racct, arg2, arg3);
1543 }
1544 }
1545 if (post != NULL)
1546 (post)();
1547 rw_runlock(&uihashtbl_lock);
1548 }
1549 #endif
1550
1551 static inline int
chglimit(struct uidinfo * uip,long * limit,int diff,rlim_t max,const char * name)1552 chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char *name)
1553 {
1554 long new;
1555
1556 /* Don't allow them to exceed max, but allow subtraction. */
1557 new = atomic_fetchadd_long(limit, (long)diff) + diff;
1558 if (diff > 0 && max != 0) {
1559 if (new < 0 || new > max) {
1560 atomic_subtract_long(limit, (long)diff);
1561 return (0);
1562 }
1563 } else if (new < 0)
1564 printf("negative %s for uid = %d\n", name, uip->ui_uid);
1565 return (1);
1566 }
1567
1568 /*
1569 * Change the count associated with number of processes
1570 * a given user is using. When 'max' is 0, don't enforce a limit
1571 */
1572 int
chgproccnt(struct uidinfo * uip,int diff,rlim_t max)1573 chgproccnt(struct uidinfo *uip, int diff, rlim_t max)
1574 {
1575
1576 return (chglimit(uip, &uip->ui_proccnt, diff, max, "proccnt"));
1577 }
1578
1579 /*
1580 * Change the total socket buffer size a user has used.
1581 */
1582 int
chgsbsize(struct uidinfo * uip,u_int * hiwat,u_int to,rlim_t max)1583 chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t max)
1584 {
1585 int diff, rv;
1586
1587 diff = to - *hiwat;
1588 if (diff > 0 && max == 0) {
1589 rv = 0;
1590 } else {
1591 rv = chglimit(uip, &uip->ui_sbsize, diff, max, "sbsize");
1592 if (rv != 0)
1593 *hiwat = to;
1594 }
1595 return (rv);
1596 }
1597
1598 /*
1599 * Change the count associated with number of pseudo-terminals
1600 * a given user is using. When 'max' is 0, don't enforce a limit
1601 */
1602 int
chgptscnt(struct uidinfo * uip,int diff,rlim_t max)1603 chgptscnt(struct uidinfo *uip, int diff, rlim_t max)
1604 {
1605
1606 return (chglimit(uip, &uip->ui_ptscnt, diff, max, "ptscnt"));
1607 }
1608
1609 int
chgkqcnt(struct uidinfo * uip,int diff,rlim_t max)1610 chgkqcnt(struct uidinfo *uip, int diff, rlim_t max)
1611 {
1612
1613 return (chglimit(uip, &uip->ui_kqcnt, diff, max, "kqcnt"));
1614 }
1615
1616 int
chgumtxcnt(struct uidinfo * uip,int diff,rlim_t max)1617 chgumtxcnt(struct uidinfo *uip, int diff, rlim_t max)
1618 {
1619
1620 return (chglimit(uip, &uip->ui_umtxcnt, diff, max, "umtxcnt"));
1621 }
1622
1623 int
chgpipecnt(struct uidinfo * uip,int diff,rlim_t max)1624 chgpipecnt(struct uidinfo *uip, int diff, rlim_t max)
1625 {
1626
1627 return (chglimit(uip, &uip->ui_pipecnt, diff, max, "pipecnt"));
1628 }
1629