Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_resource.c
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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 * @(#)kern_resource.c 8.5 (Berkeley) 1/21/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/sysproto.h> 45 #include <sys/file.h> 46 #include <sys/kernel.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/mutex.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/refcount.h> 53 #include <sys/racct.h> 54 #include <sys/resourcevar.h> 55 #include <sys/rwlock.h> 56 #include <sys/sched.h> 57 #include <sys/sx.h> 58 #include <sys/syscallsubr.h> 59 #include <sys/sysctl.h> 60 #include <sys/sysent.h> 61 #include <sys/time.h> 62 #include <sys/umtx.h> 63 64 #include <vm/vm.h> 65 #include <vm/vm_param.h> 66 #include <vm/pmap.h> 67 #include <vm/vm_map.h> 68 69 70 static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures"); 71 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures"); 72 #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) 73 static struct rwlock uihashtbl_lock; 74 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl; 75 static u_long uihash; /* size of hash table - 1 */ 76 77 static void calcru1(struct proc *p, struct rusage_ext *ruxp, 78 struct timeval *up, struct timeval *sp); 79 static int donice(struct thread *td, struct proc *chgp, int n); 80 static struct uidinfo *uilookup(uid_t uid); 81 static void ruxagg_locked(struct rusage_ext *rux, struct thread *td); 82 83 /* 84 * Resource controls and accounting. 85 */ 86 #ifndef _SYS_SYSPROTO_H_ 87 struct getpriority_args { 88 int which; 89 int who; 90 }; 91 #endif 92 int 93 sys_getpriority(struct thread *td, struct getpriority_args *uap) 94 { 95 struct proc *p; 96 struct pgrp *pg; 97 int error, low; 98 99 error = 0; 100 low = PRIO_MAX + 1; 101 switch (uap->which) { 102 103 case PRIO_PROCESS: 104 if (uap->who == 0) 105 low = td->td_proc->p_nice; 106 else { 107 p = pfind(uap->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 (uap->who == 0) { 119 pg = td->td_proc->p_pgrp; 120 PGRP_LOCK(pg); 121 } else { 122 pg = pgfind(uap->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 (uap->who == 0) 143 uap->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 == uap->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 176 sys_setpriority(struct thread *td, struct setpriority_args *uap) 177 { 178 struct proc *curp, *p; 179 struct pgrp *pg; 180 int found = 0, error = 0; 181 182 curp = td->td_proc; 183 switch (uap->which) { 184 case PRIO_PROCESS: 185 if (uap->who == 0) { 186 PROC_LOCK(curp); 187 error = donice(td, curp, uap->prio); 188 PROC_UNLOCK(curp); 189 } else { 190 p = pfind(uap->who); 191 if (p == NULL) 192 break; 193 error = p_cansee(td, p); 194 if (error == 0) 195 error = donice(td, p, uap->prio); 196 PROC_UNLOCK(p); 197 } 198 found++; 199 break; 200 201 case PRIO_PGRP: 202 sx_slock(&proctree_lock); 203 if (uap->who == 0) { 204 pg = curp->p_pgrp; 205 PGRP_LOCK(pg); 206 } else { 207 pg = pgfind(uap->who); 208 if (pg == NULL) { 209 sx_sunlock(&proctree_lock); 210 break; 211 } 212 } 213 sx_sunlock(&proctree_lock); 214 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 215 PROC_LOCK(p); 216 if (p->p_state == PRS_NORMAL && 217 p_cansee(td, p) == 0) { 218 error = donice(td, p, uap->prio); 219 found++; 220 } 221 PROC_UNLOCK(p); 222 } 223 PGRP_UNLOCK(pg); 224 break; 225 226 case PRIO_USER: 227 if (uap->who == 0) 228 uap->who = td->td_ucred->cr_uid; 229 sx_slock(&allproc_lock); 230 FOREACH_PROC_IN_SYSTEM(p) { 231 PROC_LOCK(p); 232 if (p->p_state == PRS_NORMAL && 233 p->p_ucred->cr_uid == uap->who && 234 p_cansee(td, p) == 0) { 235 error = donice(td, p, uap->prio); 236 found++; 237 } 238 PROC_UNLOCK(p); 239 } 240 sx_sunlock(&allproc_lock); 241 break; 242 243 default: 244 error = EINVAL; 245 break; 246 } 247 if (found == 0 && error == 0) 248 error = ESRCH; 249 return (error); 250 } 251 252 /* 253 * Set "nice" for a (whole) process. 254 */ 255 static int 256 donice(struct thread *td, struct proc *p, int n) 257 { 258 int error; 259 260 PROC_LOCK_ASSERT(p, MA_OWNED); 261 if ((error = p_cansched(td, p))) 262 return (error); 263 if (n > PRIO_MAX) 264 n = PRIO_MAX; 265 if (n < PRIO_MIN) 266 n = PRIO_MIN; 267 if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0) 268 return (EACCES); 269 sched_nice(p, n); 270 return (0); 271 } 272 273 static int unprivileged_idprio; 274 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW, 275 &unprivileged_idprio, 0, "Allow non-root users to set an idle priority"); 276 277 /* 278 * Set realtime priority for LWP. 279 */ 280 #ifndef _SYS_SYSPROTO_H_ 281 struct rtprio_thread_args { 282 int function; 283 lwpid_t lwpid; 284 struct rtprio *rtp; 285 }; 286 #endif 287 int 288 sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap) 289 { 290 struct proc *p; 291 struct rtprio rtp; 292 struct thread *td1; 293 int cierror, error; 294 295 /* Perform copyin before acquiring locks if needed. */ 296 if (uap->function == RTP_SET) 297 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio)); 298 else 299 cierror = 0; 300 301 if (uap->lwpid == 0 || uap->lwpid == td->td_tid) { 302 p = td->td_proc; 303 td1 = td; 304 PROC_LOCK(p); 305 } else { 306 td1 = tdfind(uap->lwpid, -1); 307 if (td1 == NULL) 308 return (ESRCH); 309 p = td1->td_proc; 310 } 311 312 switch (uap->function) { 313 case RTP_LOOKUP: 314 if ((error = p_cansee(td, p))) 315 break; 316 pri_to_rtp(td1, &rtp); 317 PROC_UNLOCK(p); 318 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio))); 319 case RTP_SET: 320 if ((error = p_cansched(td, p)) || (error = cierror)) 321 break; 322 323 /* Disallow setting rtprio in most cases if not superuser. */ 324 325 /* 326 * Realtime priority has to be restricted for reasons which 327 * should be obvious. However, for idleprio processes, there is 328 * a potential for system deadlock if an idleprio process gains 329 * a lock on a resource that other processes need (and the 330 * idleprio process can't run due to a CPU-bound normal 331 * process). Fix me! XXX 332 * 333 * This problem is not only related to idleprio process. 334 * A user level program can obtain a file lock and hold it 335 * indefinitely. Additionally, without idleprio processes it is 336 * still conceivable that a program with low priority will never 337 * get to run. In short, allowing this feature might make it 338 * easier to lock a resource indefinitely, but it is not the 339 * only thing that makes it possible. 340 */ 341 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME || 342 (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE && 343 unprivileged_idprio == 0)) { 344 error = priv_check(td, PRIV_SCHED_RTPRIO); 345 if (error) 346 break; 347 } 348 error = rtp_to_pri(&rtp, td1); 349 break; 350 default: 351 error = EINVAL; 352 break; 353 } 354 PROC_UNLOCK(p); 355 return (error); 356 } 357 358 /* 359 * Set realtime priority. 360 */ 361 #ifndef _SYS_SYSPROTO_H_ 362 struct rtprio_args { 363 int function; 364 pid_t pid; 365 struct rtprio *rtp; 366 }; 367 #endif 368 int 369 sys_rtprio(struct thread *td, struct rtprio_args *uap) 370 { 371 struct proc *p; 372 struct thread *tdp; 373 struct rtprio rtp; 374 int cierror, error; 375 376 /* Perform copyin before acquiring locks if needed. */ 377 if (uap->function == RTP_SET) 378 cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio)); 379 else 380 cierror = 0; 381 382 if (uap->pid == 0) { 383 p = td->td_proc; 384 PROC_LOCK(p); 385 } else { 386 p = pfind(uap->pid); 387 if (p == NULL) 388 return (ESRCH); 389 } 390 391 switch (uap->function) { 392 case RTP_LOOKUP: 393 if ((error = p_cansee(td, p))) 394 break; 395 /* 396 * Return OUR priority if no pid specified, 397 * or if one is, report the highest priority 398 * in the process. There isn't much more you can do as 399 * there is only room to return a single priority. 400 * Note: specifying our own pid is not the same 401 * as leaving it zero. 402 */ 403 if (uap->pid == 0) { 404 pri_to_rtp(td, &rtp); 405 } else { 406 struct rtprio rtp2; 407 408 rtp.type = RTP_PRIO_IDLE; 409 rtp.prio = RTP_PRIO_MAX; 410 FOREACH_THREAD_IN_PROC(p, tdp) { 411 pri_to_rtp(tdp, &rtp2); 412 if (rtp2.type < rtp.type || 413 (rtp2.type == rtp.type && 414 rtp2.prio < rtp.prio)) { 415 rtp.type = rtp2.type; 416 rtp.prio = rtp2.prio; 417 } 418 } 419 } 420 PROC_UNLOCK(p); 421 return (copyout(&rtp, uap->rtp, sizeof(struct rtprio))); 422 case RTP_SET: 423 if ((error = p_cansched(td, p)) || (error = cierror)) 424 break; 425 426 /* 427 * Disallow setting rtprio in most cases if not superuser. 428 * See the comment in sys_rtprio_thread about idprio 429 * threads holding a lock. 430 */ 431 if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME || 432 (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE && 433 !unprivileged_idprio)) { 434 error = priv_check(td, PRIV_SCHED_RTPRIO); 435 if (error) 436 break; 437 } 438 439 /* 440 * If we are setting our own priority, set just our 441 * thread but if we are doing another process, 442 * do all the threads on that process. If we 443 * specify our own pid we do the latter. 444 */ 445 if (uap->pid == 0) { 446 error = rtp_to_pri(&rtp, td); 447 } else { 448 FOREACH_THREAD_IN_PROC(p, td) { 449 if ((error = rtp_to_pri(&rtp, td)) != 0) 450 break; 451 } 452 } 453 break; 454 default: 455 error = EINVAL; 456 break; 457 } 458 PROC_UNLOCK(p); 459 return (error); 460 } 461 462 int 463 rtp_to_pri(struct rtprio *rtp, struct thread *td) 464 { 465 u_char newpri, oldclass, oldpri; 466 467 switch (RTP_PRIO_BASE(rtp->type)) { 468 case RTP_PRIO_REALTIME: 469 if (rtp->prio > RTP_PRIO_MAX) 470 return (EINVAL); 471 newpri = PRI_MIN_REALTIME + rtp->prio; 472 break; 473 case RTP_PRIO_NORMAL: 474 if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) 475 return (EINVAL); 476 newpri = PRI_MIN_TIMESHARE + rtp->prio; 477 break; 478 case RTP_PRIO_IDLE: 479 if (rtp->prio > RTP_PRIO_MAX) 480 return (EINVAL); 481 newpri = PRI_MIN_IDLE + rtp->prio; 482 break; 483 default: 484 return (EINVAL); 485 } 486 487 thread_lock(td); 488 oldclass = td->td_pri_class; 489 sched_class(td, rtp->type); /* XXX fix */ 490 oldpri = td->td_user_pri; 491 sched_user_prio(td, newpri); 492 if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL || 493 td->td_pri_class != RTP_PRIO_NORMAL)) 494 sched_prio(td, td->td_user_pri); 495 if (TD_ON_UPILOCK(td) && oldpri != newpri) { 496 critical_enter(); 497 thread_unlock(td); 498 umtx_pi_adjust(td, oldpri); 499 critical_exit(); 500 } else 501 thread_unlock(td); 502 return (0); 503 } 504 505 void 506 pri_to_rtp(struct thread *td, struct rtprio *rtp) 507 { 508 509 thread_lock(td); 510 switch (PRI_BASE(td->td_pri_class)) { 511 case PRI_REALTIME: 512 rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME; 513 break; 514 case PRI_TIMESHARE: 515 rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE; 516 break; 517 case PRI_IDLE: 518 rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE; 519 break; 520 default: 521 break; 522 } 523 rtp->type = td->td_pri_class; 524 thread_unlock(td); 525 } 526 527 #if defined(COMPAT_43) 528 #ifndef _SYS_SYSPROTO_H_ 529 struct osetrlimit_args { 530 u_int which; 531 struct orlimit *rlp; 532 }; 533 #endif 534 int 535 osetrlimit(struct thread *td, struct osetrlimit_args *uap) 536 { 537 struct orlimit olim; 538 struct rlimit lim; 539 int error; 540 541 if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit)))) 542 return (error); 543 lim.rlim_cur = olim.rlim_cur; 544 lim.rlim_max = olim.rlim_max; 545 error = kern_setrlimit(td, uap->which, &lim); 546 return (error); 547 } 548 549 #ifndef _SYS_SYSPROTO_H_ 550 struct ogetrlimit_args { 551 u_int which; 552 struct orlimit *rlp; 553 }; 554 #endif 555 int 556 ogetrlimit(struct thread *td, struct ogetrlimit_args *uap) 557 { 558 struct orlimit olim; 559 struct rlimit rl; 560 int error; 561 562 if (uap->which >= RLIM_NLIMITS) 563 return (EINVAL); 564 lim_rlimit(td, uap->which, &rl); 565 566 /* 567 * XXX would be more correct to convert only RLIM_INFINITY to the 568 * old RLIM_INFINITY and fail with EOVERFLOW for other larger 569 * values. Most 64->32 and 32->16 conversions, including not 570 * unimportant ones of uids are even more broken than what we 571 * do here (they blindly truncate). We don't do this correctly 572 * here since we have little experience with EOVERFLOW yet. 573 * Elsewhere, getuid() can't fail... 574 */ 575 olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur; 576 olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max; 577 error = copyout(&olim, uap->rlp, sizeof(olim)); 578 return (error); 579 } 580 #endif /* COMPAT_43 */ 581 582 #ifndef _SYS_SYSPROTO_H_ 583 struct __setrlimit_args { 584 u_int which; 585 struct rlimit *rlp; 586 }; 587 #endif 588 int 589 sys_setrlimit(struct thread *td, struct __setrlimit_args *uap) 590 { 591 struct rlimit alim; 592 int error; 593 594 if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit)))) 595 return (error); 596 error = kern_setrlimit(td, uap->which, &alim); 597 return (error); 598 } 599 600 static void 601 lim_cb(void *arg) 602 { 603 struct rlimit rlim; 604 struct thread *td; 605 struct proc *p; 606 607 p = arg; 608 PROC_LOCK_ASSERT(p, MA_OWNED); 609 /* 610 * Check if the process exceeds its cpu resource allocation. If 611 * it reaches the max, arrange to kill the process in ast(). 612 */ 613 if (p->p_cpulimit == RLIM_INFINITY) 614 return; 615 PROC_STATLOCK(p); 616 FOREACH_THREAD_IN_PROC(p, td) { 617 ruxagg(p, td); 618 } 619 PROC_STATUNLOCK(p); 620 if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) { 621 lim_rlimit_proc(p, RLIMIT_CPU, &rlim); 622 if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) { 623 killproc(p, "exceeded maximum CPU limit"); 624 } else { 625 if (p->p_cpulimit < rlim.rlim_max) 626 p->p_cpulimit += 5; 627 kern_psignal(p, SIGXCPU); 628 } 629 } 630 if ((p->p_flag & P_WEXIT) == 0) 631 callout_reset_sbt(&p->p_limco, SBT_1S, 0, 632 lim_cb, p, C_PREL(1)); 633 } 634 635 int 636 kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp) 637 { 638 639 return (kern_proc_setrlimit(td, td->td_proc, which, limp)); 640 } 641 642 int 643 kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which, 644 struct rlimit *limp) 645 { 646 struct plimit *newlim, *oldlim; 647 struct rlimit *alimp; 648 struct rlimit oldssiz; 649 int error; 650 651 if (which >= RLIM_NLIMITS) 652 return (EINVAL); 653 654 /* 655 * Preserve historical bugs by treating negative limits as unsigned. 656 */ 657 if (limp->rlim_cur < 0) 658 limp->rlim_cur = RLIM_INFINITY; 659 if (limp->rlim_max < 0) 660 limp->rlim_max = RLIM_INFINITY; 661 662 oldssiz.rlim_cur = 0; 663 newlim = lim_alloc(); 664 PROC_LOCK(p); 665 oldlim = p->p_limit; 666 alimp = &oldlim->pl_rlimit[which]; 667 if (limp->rlim_cur > alimp->rlim_max || 668 limp->rlim_max > alimp->rlim_max) 669 if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) { 670 PROC_UNLOCK(p); 671 lim_free(newlim); 672 return (error); 673 } 674 if (limp->rlim_cur > limp->rlim_max) 675 limp->rlim_cur = limp->rlim_max; 676 lim_copy(newlim, oldlim); 677 alimp = &newlim->pl_rlimit[which]; 678 679 switch (which) { 680 681 case RLIMIT_CPU: 682 if (limp->rlim_cur != RLIM_INFINITY && 683 p->p_cpulimit == RLIM_INFINITY) 684 callout_reset_sbt(&p->p_limco, SBT_1S, 0, 685 lim_cb, p, C_PREL(1)); 686 p->p_cpulimit = limp->rlim_cur; 687 break; 688 case RLIMIT_DATA: 689 if (limp->rlim_cur > maxdsiz) 690 limp->rlim_cur = maxdsiz; 691 if (limp->rlim_max > maxdsiz) 692 limp->rlim_max = maxdsiz; 693 break; 694 695 case RLIMIT_STACK: 696 if (limp->rlim_cur > maxssiz) 697 limp->rlim_cur = maxssiz; 698 if (limp->rlim_max > maxssiz) 699 limp->rlim_max = maxssiz; 700 oldssiz = *alimp; 701 if (p->p_sysent->sv_fixlimit != NULL) 702 p->p_sysent->sv_fixlimit(&oldssiz, 703 RLIMIT_STACK); 704 break; 705 706 case RLIMIT_NOFILE: 707 if (limp->rlim_cur > maxfilesperproc) 708 limp->rlim_cur = maxfilesperproc; 709 if (limp->rlim_max > maxfilesperproc) 710 limp->rlim_max = maxfilesperproc; 711 break; 712 713 case RLIMIT_NPROC: 714 if (limp->rlim_cur > maxprocperuid) 715 limp->rlim_cur = maxprocperuid; 716 if (limp->rlim_max > maxprocperuid) 717 limp->rlim_max = maxprocperuid; 718 if (limp->rlim_cur < 1) 719 limp->rlim_cur = 1; 720 if (limp->rlim_max < 1) 721 limp->rlim_max = 1; 722 break; 723 } 724 if (p->p_sysent->sv_fixlimit != NULL) 725 p->p_sysent->sv_fixlimit(limp, which); 726 *alimp = *limp; 727 p->p_limit = newlim; 728 PROC_UPDATE_COW(p); 729 PROC_UNLOCK(p); 730 lim_free(oldlim); 731 732 if (which == RLIMIT_STACK && 733 /* 734 * Skip calls from exec_new_vmspace(), done when stack is 735 * not mapped yet. 736 */ 737 (td != curthread || (p->p_flag & P_INEXEC) == 0)) { 738 /* 739 * Stack is allocated to the max at exec time with only 740 * "rlim_cur" bytes accessible. If stack limit is going 741 * up make more accessible, if going down make inaccessible. 742 */ 743 if (limp->rlim_cur != oldssiz.rlim_cur) { 744 vm_offset_t addr; 745 vm_size_t size; 746 vm_prot_t prot; 747 748 if (limp->rlim_cur > oldssiz.rlim_cur) { 749 prot = p->p_sysent->sv_stackprot; 750 size = limp->rlim_cur - oldssiz.rlim_cur; 751 addr = p->p_sysent->sv_usrstack - 752 limp->rlim_cur; 753 } else { 754 prot = VM_PROT_NONE; 755 size = oldssiz.rlim_cur - limp->rlim_cur; 756 addr = p->p_sysent->sv_usrstack - 757 oldssiz.rlim_cur; 758 } 759 addr = trunc_page(addr); 760 size = round_page(size); 761 (void)vm_map_protect(&p->p_vmspace->vm_map, 762 addr, addr + size, prot, FALSE); 763 } 764 } 765 766 return (0); 767 } 768 769 #ifndef _SYS_SYSPROTO_H_ 770 struct __getrlimit_args { 771 u_int which; 772 struct rlimit *rlp; 773 }; 774 #endif 775 /* ARGSUSED */ 776 int 777 sys_getrlimit(struct thread *td, struct __getrlimit_args *uap) 778 { 779 struct rlimit rlim; 780 int error; 781 782 if (uap->which >= RLIM_NLIMITS) 783 return (EINVAL); 784 lim_rlimit(td, uap->which, &rlim); 785 error = copyout(&rlim, uap->rlp, sizeof(struct rlimit)); 786 return (error); 787 } 788 789 /* 790 * Transform the running time and tick information for children of proc p 791 * into user and system time usage. 792 */ 793 void 794 calccru(struct proc *p, struct timeval *up, struct timeval *sp) 795 { 796 797 PROC_LOCK_ASSERT(p, MA_OWNED); 798 calcru1(p, &p->p_crux, up, sp); 799 } 800 801 /* 802 * Transform the running time and tick information in proc p into user 803 * and system time usage. If appropriate, include the current time slice 804 * on this CPU. 805 */ 806 void 807 calcru(struct proc *p, struct timeval *up, struct timeval *sp) 808 { 809 struct thread *td; 810 uint64_t runtime, u; 811 812 PROC_LOCK_ASSERT(p, MA_OWNED); 813 PROC_STATLOCK_ASSERT(p, MA_OWNED); 814 /* 815 * If we are getting stats for the current process, then add in the 816 * stats that this thread has accumulated in its current time slice. 817 * We reset the thread and CPU state as if we had performed a context 818 * switch right here. 819 */ 820 td = curthread; 821 if (td->td_proc == p) { 822 u = cpu_ticks(); 823 runtime = u - PCPU_GET(switchtime); 824 td->td_runtime += runtime; 825 td->td_incruntime += runtime; 826 PCPU_SET(switchtime, u); 827 } 828 /* Make sure the per-thread stats are current. */ 829 FOREACH_THREAD_IN_PROC(p, td) { 830 if (td->td_incruntime == 0) 831 continue; 832 ruxagg(p, td); 833 } 834 calcru1(p, &p->p_rux, up, sp); 835 } 836 837 /* Collect resource usage for a single thread. */ 838 void 839 rufetchtd(struct thread *td, struct rusage *ru) 840 { 841 struct proc *p; 842 uint64_t runtime, u; 843 844 p = td->td_proc; 845 PROC_STATLOCK_ASSERT(p, MA_OWNED); 846 THREAD_LOCK_ASSERT(td, MA_OWNED); 847 /* 848 * If we are getting stats for the current thread, then add in the 849 * stats that this thread has accumulated in its current time slice. 850 * We reset the thread and CPU state as if we had performed a context 851 * switch right here. 852 */ 853 if (td == curthread) { 854 u = cpu_ticks(); 855 runtime = u - PCPU_GET(switchtime); 856 td->td_runtime += runtime; 857 td->td_incruntime += runtime; 858 PCPU_SET(switchtime, u); 859 } 860 ruxagg(p, td); 861 *ru = td->td_ru; 862 calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime); 863 } 864 865 /* XXX: the MI version is too slow to use: */ 866 #ifndef __HAVE_INLINE_FLSLL 867 #define flsll(x) (fls((x) >> 32) != 0 ? fls((x) >> 32) + 32 : fls(x)) 868 #endif 869 870 static uint64_t 871 mul64_by_fraction(uint64_t a, uint64_t b, uint64_t c) 872 { 873 uint64_t acc, bh, bl; 874 int i, s, sa, sb; 875 876 /* 877 * Calculate (a * b) / c accurately enough without overflowing. c 878 * must be nonzero, and its top bit must be 0. a or b must be 879 * <= c, and the implementation is tuned for b <= c. 880 * 881 * The comments about times are for use in calcru1() with units of 882 * microseconds for 'a' and stathz ticks at 128 Hz for b and c. 883 * 884 * Let n be the number of top zero bits in c. Each iteration 885 * either returns, or reduces b by right shifting it by at least n. 886 * The number of iterations is at most 1 + 64 / n, and the error is 887 * at most the number of iterations. 888 * 889 * It is very unusual to need even 2 iterations. Previous 890 * implementations overflowed essentially by returning early in the 891 * first iteration, with n = 38 giving overflow at 105+ hours and 892 * n = 32 giving overlow at at 388+ days despite a more careful 893 * calculation. 388 days is a reasonable uptime, and the calculation 894 * needs to work for the uptime times the number of CPUs since 'a' 895 * is per-process. 896 */ 897 if (a >= (uint64_t)1 << 63) 898 return (0); /* Unsupported arg -- can't happen. */ 899 acc = 0; 900 for (i = 0; i < 128; i++) { 901 sa = flsll(a); 902 sb = flsll(b); 903 if (sa + sb <= 64) 904 /* Up to 105 hours on first iteration. */ 905 return (acc + (a * b) / c); 906 if (a >= c) { 907 /* 908 * This reduction is based on a = q * c + r, with the 909 * remainder r < c. 'a' may be large to start, and 910 * moving bits from b into 'a' at the end of the loop 911 * sets the top bit of 'a', so the reduction makes 912 * significant progress. 913 */ 914 acc += (a / c) * b; 915 a %= c; 916 sa = flsll(a); 917 if (sa + sb <= 64) 918 /* Up to 388 days on first iteration. */ 919 return (acc + (a * b) / c); 920 } 921 922 /* 923 * This step writes a * b as a * ((bh << s) + bl) = 924 * a * (bh << s) + a * bl = (a << s) * bh + a * bl. The 2 925 * additive terms are handled separately. Splitting in 926 * this way is linear except for rounding errors. 927 * 928 * s = 64 - sa is the maximum such that a << s fits in 64 929 * bits. Since a < c and c has at least 1 zero top bit, 930 * sa < 64 and s > 0. Thus this step makes progress by 931 * reducing b (it increases 'a', but taking remainders on 932 * the next iteration completes the reduction). 933 * 934 * Finally, the choice for s is just what is needed to keep 935 * a * bl from overflowing, so we don't need complications 936 * like a recursive call mul64_by_fraction(a, bl, c) to 937 * handle the second additive term. 938 */ 939 s = 64 - sa; 940 bh = b >> s; 941 bl = b - (bh << s); 942 acc += (a * bl) / c; 943 a <<= s; 944 b = bh; 945 } 946 return (0); /* Algorithm failure -- can't happen. */ 947 } 948 949 static void 950 calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up, 951 struct timeval *sp) 952 { 953 /* {user, system, interrupt, total} {ticks, usec}: */ 954 uint64_t ut, uu, st, su, it, tt, tu; 955 956 ut = ruxp->rux_uticks; 957 st = ruxp->rux_sticks; 958 it = ruxp->rux_iticks; 959 tt = ut + st + it; 960 if (tt == 0) { 961 /* Avoid divide by zero */ 962 st = 1; 963 tt = 1; 964 } 965 tu = cputick2usec(ruxp->rux_runtime); 966 if ((int64_t)tu < 0) { 967 /* XXX: this should be an assert /phk */ 968 printf("calcru: negative runtime of %jd usec for pid %d (%s)\n", 969 (intmax_t)tu, p->p_pid, p->p_comm); 970 tu = ruxp->rux_tu; 971 } 972 973 /* Subdivide tu. Avoid overflow in the multiplications. */ 974 if (__predict_true(tu <= ((uint64_t)1 << 38) && tt <= (1 << 26))) { 975 /* Up to 76 hours when stathz is 128. */ 976 uu = (tu * ut) / tt; 977 su = (tu * st) / tt; 978 } else { 979 uu = mul64_by_fraction(tu, ut, tt); 980 su = mul64_by_fraction(tu, st, tt); 981 } 982 983 if (tu >= ruxp->rux_tu) { 984 /* 985 * The normal case, time increased. 986 * Enforce monotonicity of bucketed numbers. 987 */ 988 if (uu < ruxp->rux_uu) 989 uu = ruxp->rux_uu; 990 if (su < ruxp->rux_su) 991 su = ruxp->rux_su; 992 } else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) { 993 /* 994 * When we calibrate the cputicker, it is not uncommon to 995 * see the presumably fixed frequency increase slightly over 996 * time as a result of thermal stabilization and NTP 997 * discipline (of the reference clock). We therefore ignore 998 * a bit of backwards slop because we expect to catch up 999 * shortly. We use a 3 microsecond limit to catch low 1000 * counts and a 1% limit for high counts. 1001 */ 1002 uu = ruxp->rux_uu; 1003 su = ruxp->rux_su; 1004 tu = ruxp->rux_tu; 1005 } else { /* tu < ruxp->rux_tu */ 1006 /* 1007 * What happened here was likely that a laptop, which ran at 1008 * a reduced clock frequency at boot, kicked into high gear. 1009 * The wisdom of spamming this message in that case is 1010 * dubious, but it might also be indicative of something 1011 * serious, so lets keep it and hope laptops can be made 1012 * more truthful about their CPU speed via ACPI. 1013 */ 1014 printf("calcru: runtime went backwards from %ju usec " 1015 "to %ju usec for pid %d (%s)\n", 1016 (uintmax_t)ruxp->rux_tu, (uintmax_t)tu, 1017 p->p_pid, p->p_comm); 1018 } 1019 1020 ruxp->rux_uu = uu; 1021 ruxp->rux_su = su; 1022 ruxp->rux_tu = tu; 1023 1024 up->tv_sec = uu / 1000000; 1025 up->tv_usec = uu % 1000000; 1026 sp->tv_sec = su / 1000000; 1027 sp->tv_usec = su % 1000000; 1028 } 1029 1030 #ifndef _SYS_SYSPROTO_H_ 1031 struct getrusage_args { 1032 int who; 1033 struct rusage *rusage; 1034 }; 1035 #endif 1036 int 1037 sys_getrusage(struct thread *td, struct getrusage_args *uap) 1038 { 1039 struct rusage ru; 1040 int error; 1041 1042 error = kern_getrusage(td, uap->who, &ru); 1043 if (error == 0) 1044 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 1045 return (error); 1046 } 1047 1048 int 1049 kern_getrusage(struct thread *td, int who, struct rusage *rup) 1050 { 1051 struct proc *p; 1052 int error; 1053 1054 error = 0; 1055 p = td->td_proc; 1056 PROC_LOCK(p); 1057 switch (who) { 1058 case RUSAGE_SELF: 1059 rufetchcalc(p, rup, &rup->ru_utime, 1060 &rup->ru_stime); 1061 break; 1062 1063 case RUSAGE_CHILDREN: 1064 *rup = p->p_stats->p_cru; 1065 calccru(p, &rup->ru_utime, &rup->ru_stime); 1066 break; 1067 1068 case RUSAGE_THREAD: 1069 PROC_STATLOCK(p); 1070 thread_lock(td); 1071 rufetchtd(td, rup); 1072 thread_unlock(td); 1073 PROC_STATUNLOCK(p); 1074 break; 1075 1076 default: 1077 error = EINVAL; 1078 } 1079 PROC_UNLOCK(p); 1080 return (error); 1081 } 1082 1083 void 1084 rucollect(struct rusage *ru, struct rusage *ru2) 1085 { 1086 long *ip, *ip2; 1087 int i; 1088 1089 if (ru->ru_maxrss < ru2->ru_maxrss) 1090 ru->ru_maxrss = ru2->ru_maxrss; 1091 ip = &ru->ru_first; 1092 ip2 = &ru2->ru_first; 1093 for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--) 1094 *ip++ += *ip2++; 1095 } 1096 1097 void 1098 ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2, 1099 struct rusage_ext *rux2) 1100 { 1101 1102 rux->rux_runtime += rux2->rux_runtime; 1103 rux->rux_uticks += rux2->rux_uticks; 1104 rux->rux_sticks += rux2->rux_sticks; 1105 rux->rux_iticks += rux2->rux_iticks; 1106 rux->rux_uu += rux2->rux_uu; 1107 rux->rux_su += rux2->rux_su; 1108 rux->rux_tu += rux2->rux_tu; 1109 rucollect(ru, ru2); 1110 } 1111 1112 /* 1113 * Aggregate tick counts into the proc's rusage_ext. 1114 */ 1115 static void 1116 ruxagg_locked(struct rusage_ext *rux, struct thread *td) 1117 { 1118 1119 THREAD_LOCK_ASSERT(td, MA_OWNED); 1120 PROC_STATLOCK_ASSERT(td->td_proc, MA_OWNED); 1121 rux->rux_runtime += td->td_incruntime; 1122 rux->rux_uticks += td->td_uticks; 1123 rux->rux_sticks += td->td_sticks; 1124 rux->rux_iticks += td->td_iticks; 1125 } 1126 1127 void 1128 ruxagg(struct proc *p, struct thread *td) 1129 { 1130 1131 thread_lock(td); 1132 ruxagg_locked(&p->p_rux, td); 1133 ruxagg_locked(&td->td_rux, td); 1134 td->td_incruntime = 0; 1135 td->td_uticks = 0; 1136 td->td_iticks = 0; 1137 td->td_sticks = 0; 1138 thread_unlock(td); 1139 } 1140 1141 /* 1142 * Update the rusage_ext structure and fetch a valid aggregate rusage 1143 * for proc p if storage for one is supplied. 1144 */ 1145 void 1146 rufetch(struct proc *p, struct rusage *ru) 1147 { 1148 struct thread *td; 1149 1150 PROC_STATLOCK_ASSERT(p, MA_OWNED); 1151 1152 *ru = p->p_ru; 1153 if (p->p_numthreads > 0) { 1154 FOREACH_THREAD_IN_PROC(p, td) { 1155 ruxagg(p, td); 1156 rucollect(ru, &td->td_ru); 1157 } 1158 } 1159 } 1160 1161 /* 1162 * Atomically perform a rufetch and a calcru together. 1163 * Consumers, can safely assume the calcru is executed only once 1164 * rufetch is completed. 1165 */ 1166 void 1167 rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up, 1168 struct timeval *sp) 1169 { 1170 1171 PROC_STATLOCK(p); 1172 rufetch(p, ru); 1173 calcru(p, up, sp); 1174 PROC_STATUNLOCK(p); 1175 } 1176 1177 /* 1178 * Allocate a new resource limits structure and initialize its 1179 * reference count and mutex pointer. 1180 */ 1181 struct plimit * 1182 lim_alloc(void) 1183 { 1184 struct plimit *limp; 1185 1186 limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK); 1187 refcount_init(&limp->pl_refcnt, 1); 1188 return (limp); 1189 } 1190 1191 struct plimit * 1192 lim_hold(struct plimit *limp) 1193 { 1194 1195 refcount_acquire(&limp->pl_refcnt); 1196 return (limp); 1197 } 1198 1199 void 1200 lim_fork(struct proc *p1, struct proc *p2) 1201 { 1202 1203 PROC_LOCK_ASSERT(p1, MA_OWNED); 1204 PROC_LOCK_ASSERT(p2, MA_OWNED); 1205 1206 p2->p_limit = lim_hold(p1->p_limit); 1207 callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0); 1208 if (p1->p_cpulimit != RLIM_INFINITY) 1209 callout_reset_sbt(&p2->p_limco, SBT_1S, 0, 1210 lim_cb, p2, C_PREL(1)); 1211 } 1212 1213 void 1214 lim_free(struct plimit *limp) 1215 { 1216 1217 if (refcount_release(&limp->pl_refcnt)) 1218 free((void *)limp, M_PLIMIT); 1219 } 1220 1221 /* 1222 * Make a copy of the plimit structure. 1223 * We share these structures copy-on-write after fork. 1224 */ 1225 void 1226 lim_copy(struct plimit *dst, struct plimit *src) 1227 { 1228 1229 KASSERT(dst->pl_refcnt <= 1, ("lim_copy to shared limit")); 1230 bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit)); 1231 } 1232 1233 /* 1234 * Return the hard limit for a particular system resource. The 1235 * which parameter specifies the index into the rlimit array. 1236 */ 1237 rlim_t 1238 lim_max(struct thread *td, int which) 1239 { 1240 struct rlimit rl; 1241 1242 lim_rlimit(td, which, &rl); 1243 return (rl.rlim_max); 1244 } 1245 1246 rlim_t 1247 lim_max_proc(struct proc *p, int which) 1248 { 1249 struct rlimit rl; 1250 1251 lim_rlimit_proc(p, which, &rl); 1252 return (rl.rlim_max); 1253 } 1254 1255 /* 1256 * Return the current (soft) limit for a particular system resource. 1257 * The which parameter which specifies the index into the rlimit array 1258 */ 1259 rlim_t 1260 lim_cur(struct thread *td, int which) 1261 { 1262 struct rlimit rl; 1263 1264 lim_rlimit(td, which, &rl); 1265 return (rl.rlim_cur); 1266 } 1267 1268 rlim_t 1269 lim_cur_proc(struct proc *p, int which) 1270 { 1271 struct rlimit rl; 1272 1273 lim_rlimit_proc(p, which, &rl); 1274 return (rl.rlim_cur); 1275 } 1276 1277 /* 1278 * Return a copy of the entire rlimit structure for the system limit 1279 * specified by 'which' in the rlimit structure pointed to by 'rlp'. 1280 */ 1281 void 1282 lim_rlimit(struct thread *td, int which, struct rlimit *rlp) 1283 { 1284 struct proc *p = td->td_proc; 1285 1286 MPASS(td == curthread); 1287 KASSERT(which >= 0 && which < RLIM_NLIMITS, 1288 ("request for invalid resource limit")); 1289 *rlp = td->td_limit->pl_rlimit[which]; 1290 if (p->p_sysent->sv_fixlimit != NULL) 1291 p->p_sysent->sv_fixlimit(rlp, which); 1292 } 1293 1294 void 1295 lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp) 1296 { 1297 1298 PROC_LOCK_ASSERT(p, MA_OWNED); 1299 KASSERT(which >= 0 && which < RLIM_NLIMITS, 1300 ("request for invalid resource limit")); 1301 *rlp = p->p_limit->pl_rlimit[which]; 1302 if (p->p_sysent->sv_fixlimit != NULL) 1303 p->p_sysent->sv_fixlimit(rlp, which); 1304 } 1305 1306 void 1307 uihashinit(void) 1308 { 1309 1310 uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash); 1311 rw_init(&uihashtbl_lock, "uidinfo hash"); 1312 } 1313 1314 /* 1315 * Look up a uidinfo struct for the parameter uid. 1316 * uihashtbl_lock must be locked. 1317 * Increase refcount on uidinfo struct returned. 1318 */ 1319 static struct uidinfo * 1320 uilookup(uid_t uid) 1321 { 1322 struct uihashhead *uipp; 1323 struct uidinfo *uip; 1324 1325 rw_assert(&uihashtbl_lock, RA_LOCKED); 1326 uipp = UIHASH(uid); 1327 LIST_FOREACH(uip, uipp, ui_hash) 1328 if (uip->ui_uid == uid) { 1329 uihold(uip); 1330 break; 1331 } 1332 1333 return (uip); 1334 } 1335 1336 /* 1337 * Find or allocate a struct uidinfo for a particular uid. 1338 * Returns with uidinfo struct referenced. 1339 * uifree() should be called on a struct uidinfo when released. 1340 */ 1341 struct uidinfo * 1342 uifind(uid_t uid) 1343 { 1344 struct uidinfo *new_uip, *uip; 1345 struct ucred *cred; 1346 1347 cred = curthread->td_ucred; 1348 if (cred->cr_uidinfo->ui_uid == uid) { 1349 uip = cred->cr_uidinfo; 1350 uihold(uip); 1351 return (uip); 1352 } else if (cred->cr_ruidinfo->ui_uid == uid) { 1353 uip = cred->cr_ruidinfo; 1354 uihold(uip); 1355 return (uip); 1356 } 1357 1358 rw_rlock(&uihashtbl_lock); 1359 uip = uilookup(uid); 1360 rw_runlock(&uihashtbl_lock); 1361 if (uip != NULL) 1362 return (uip); 1363 1364 new_uip = malloc(sizeof(*new_uip), M_UIDINFO, M_WAITOK | M_ZERO); 1365 racct_create(&new_uip->ui_racct); 1366 refcount_init(&new_uip->ui_ref, 1); 1367 new_uip->ui_uid = uid; 1368 1369 rw_wlock(&uihashtbl_lock); 1370 /* 1371 * There's a chance someone created our uidinfo while we 1372 * were in malloc and not holding the lock, so we have to 1373 * make sure we don't insert a duplicate uidinfo. 1374 */ 1375 if ((uip = uilookup(uid)) == NULL) { 1376 LIST_INSERT_HEAD(UIHASH(uid), new_uip, ui_hash); 1377 rw_wunlock(&uihashtbl_lock); 1378 uip = new_uip; 1379 } else { 1380 rw_wunlock(&uihashtbl_lock); 1381 racct_destroy(&new_uip->ui_racct); 1382 free(new_uip, M_UIDINFO); 1383 } 1384 return (uip); 1385 } 1386 1387 /* 1388 * Place another refcount on a uidinfo struct. 1389 */ 1390 void 1391 uihold(struct uidinfo *uip) 1392 { 1393 1394 refcount_acquire(&uip->ui_ref); 1395 } 1396 1397 /*- 1398 * Since uidinfo structs have a long lifetime, we use an 1399 * opportunistic refcounting scheme to avoid locking the lookup hash 1400 * for each release. 1401 * 1402 * If the refcount hits 0, we need to free the structure, 1403 * which means we need to lock the hash. 1404 * Optimal case: 1405 * After locking the struct and lowering the refcount, if we find 1406 * that we don't need to free, simply unlock and return. 1407 * Suboptimal case: 1408 * If refcount lowering results in need to free, bump the count 1409 * back up, lose the lock and acquire the locks in the proper 1410 * order to try again. 1411 */ 1412 void 1413 uifree(struct uidinfo *uip) 1414 { 1415 int old; 1416 1417 /* Prepare for optimal case. */ 1418 old = uip->ui_ref; 1419 if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1)) 1420 return; 1421 1422 /* Prepare for suboptimal case. */ 1423 rw_wlock(&uihashtbl_lock); 1424 if (refcount_release(&uip->ui_ref) == 0) { 1425 rw_wunlock(&uihashtbl_lock); 1426 return; 1427 } 1428 1429 racct_destroy(&uip->ui_racct); 1430 LIST_REMOVE(uip, ui_hash); 1431 rw_wunlock(&uihashtbl_lock); 1432 1433 if (uip->ui_sbsize != 0) 1434 printf("freeing uidinfo: uid = %d, sbsize = %ld\n", 1435 uip->ui_uid, uip->ui_sbsize); 1436 if (uip->ui_proccnt != 0) 1437 printf("freeing uidinfo: uid = %d, proccnt = %ld\n", 1438 uip->ui_uid, uip->ui_proccnt); 1439 if (uip->ui_vmsize != 0) 1440 printf("freeing uidinfo: uid = %d, swapuse = %lld\n", 1441 uip->ui_uid, (unsigned long long)uip->ui_vmsize); 1442 free(uip, M_UIDINFO); 1443 } 1444 1445 #ifdef RACCT 1446 void 1447 ui_racct_foreach(void (*callback)(struct racct *racct, 1448 void *arg2, void *arg3), void (*pre)(void), void (*post)(void), 1449 void *arg2, void *arg3) 1450 { 1451 struct uidinfo *uip; 1452 struct uihashhead *uih; 1453 1454 rw_rlock(&uihashtbl_lock); 1455 if (pre != NULL) 1456 (pre)(); 1457 for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) { 1458 LIST_FOREACH(uip, uih, ui_hash) { 1459 (callback)(uip->ui_racct, arg2, arg3); 1460 } 1461 } 1462 if (post != NULL) 1463 (post)(); 1464 rw_runlock(&uihashtbl_lock); 1465 } 1466 #endif 1467 1468 static inline int 1469 chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char *name) 1470 { 1471 long new; 1472 1473 /* Don't allow them to exceed max, but allow subtraction. */ 1474 new = atomic_fetchadd_long(limit, (long)diff) + diff; 1475 if (diff > 0 && max != 0) { 1476 if (new < 0 || new > max) { 1477 atomic_subtract_long(limit, (long)diff); 1478 return (0); 1479 } 1480 } else if (new < 0) 1481 printf("negative %s for uid = %d\n", name, uip->ui_uid); 1482 return (1); 1483 } 1484 1485 /* 1486 * Change the count associated with number of processes 1487 * a given user is using. When 'max' is 0, don't enforce a limit 1488 */ 1489 int 1490 chgproccnt(struct uidinfo *uip, int diff, rlim_t max) 1491 { 1492 1493 return (chglimit(uip, &uip->ui_proccnt, diff, max, "proccnt")); 1494 } 1495 1496 /* 1497 * Change the total socket buffer size a user has used. 1498 */ 1499 int 1500 chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t max) 1501 { 1502 int diff, rv; 1503 1504 diff = to - *hiwat; 1505 if (diff > 0 && max == 0) { 1506 rv = 0; 1507 } else { 1508 rv = chglimit(uip, &uip->ui_sbsize, diff, max, "sbsize"); 1509 if (rv != 0) 1510 *hiwat = to; 1511 } 1512 return (rv); 1513 } 1514 1515 /* 1516 * Change the count associated with number of pseudo-terminals 1517 * a given user is using. When 'max' is 0, don't enforce a limit 1518 */ 1519 int 1520 chgptscnt(struct uidinfo *uip, int diff, rlim_t max) 1521 { 1522 1523 return (chglimit(uip, &uip->ui_ptscnt, diff, max, "ptscnt")); 1524 } 1525 1526 int 1527 chgkqcnt(struct uidinfo *uip, int diff, rlim_t max) 1528 { 1529 1530 return (chglimit(uip, &uip->ui_kqcnt, diff, max, "kqcnt")); 1531 } 1532 1533 int 1534 chgumtxcnt(struct uidinfo *uip, int diff, rlim_t max) 1535 { 1536 1537 return (chglimit(uip, &uip->ui_umtxcnt, diff, max, "umtxcnt")); 1538 }
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