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