sys/kern/kern_resource.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * (c) UNIX System Laboratories, Inc.
   5  * All or some portions of this file are derived from material licensed
   6  * to the University of California by American Telephone and Telegraph
   7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   8  * the permission of UNIX System Laboratories, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)kern_resource.c     8.5 (Berkeley) 1/21/94
  35  * $FreeBSD: src/sys/kern/kern_resource.c,v 1.55.2.5 2001/11/03 01:41:08 ps Exp $
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/sysproto.h>
  41 #include <sys/file.h>
  42 #include <sys/kern_syscall.h>
  43 #include <sys/kernel.h>
  44 #include <sys/resourcevar.h>
  45 #include <sys/malloc.h>
  46 #include <sys/proc.h>
  47 #include <sys/priv.h>
  48 #include <sys/time.h>
  49 #include <sys/lockf.h>
  50
  51 #include <vm/vm.h>
  52 #include <vm/vm_param.h>
  53 #include <sys/lock.h>
  54 #include <vm/pmap.h>
  55 #include <vm/vm_map.h>
  56
  57 #include <sys/thread2.h>
  58 #include <sys/spinlock2.h>
  59
  60 static int donice (struct proc *chgp, int n);
  61 static int doionice (struct proc *chgp, int n);
  62
  63 static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
  64 #define UIHASH(uid)     (&uihashtbl[(uid) & uihash])
  65 static struct spinlock uihash_lock;
  66 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
  67 static u_long uihash;           /* size of hash table - 1 */
  68
  69 static struct uidinfo   *uilookup (uid_t uid);
  70
  71 /*
  72  * Resource controls and accounting.
  73  */
  74
  75 struct getpriority_info {
  76         int low;
  77         int who;
  78 };
  79
  80 static int getpriority_callback(struct proc *p, void *data);
  81
  82 /*
  83  * MPALMOSTSAFE
  84  */
  85 int
  86 sys_getpriority(struct getpriority_args *uap)
  87 {
  88         struct getpriority_info info;
  89         thread_t curtd = curthread;
  90         struct proc *curp = curproc;
  91         struct proc *p;
  92         struct pgrp *pg;
  93         int low = PRIO_MAX + 1;
  94         int error;
  95
  96         switch (uap->which) {
  97         case PRIO_PROCESS:
  98                 if (uap->who == 0) {
  99                         low = curp->p_nice;
 100                 } else {
 101                         p = pfind(uap->who);
 102                         if (p) {
 103                                 lwkt_gettoken_shared(&p->p_token);
 104                                 if (PRISON_CHECK(curtd->td_ucred, p->p_ucred))
 105                                         low = p->p_nice;
 106                                 lwkt_reltoken(&p->p_token);
 107                                 PRELE(p);
 108                         }
 109                 }
 110                 break;
 111         case PRIO_PGRP:
 112                 if (uap->who == 0) {
 113                         lwkt_gettoken_shared(&curp->p_token);
 114                         pg = curp->p_pgrp;
 115                         pgref(pg);
 116                         lwkt_reltoken(&curp->p_token);
 117                 } else if ((pg = pgfind(uap->who)) == NULL) {
 118                         break;
 119                 } /* else ref held from pgfind */
 120
 121                 lwkt_gettoken_shared(&pg->pg_token);
 122                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
 123                         if (PRISON_CHECK(curtd->td_ucred, p->p_ucred) &&
 124                             p->p_nice < low) {
 125                                 low = p->p_nice;
 126                         }
 127                 }
 128                 lwkt_reltoken(&pg->pg_token);
 129                 pgrel(pg);
 130                 break;
 131         case PRIO_USER:
 132                 if (uap->who == 0)
 133                         uap->who = curtd->td_ucred->cr_uid;
 134                 info.low = low;
 135                 info.who = uap->who;
 136                 allproc_scan(getpriority_callback, &info, 0);
 137                 low = info.low;
 138                 break;
 139
 140         default:
 141                 error = EINVAL;
 142                 goto done;
 143         }
 144         if (low == PRIO_MAX + 1) {
 145                 error = ESRCH;
 146                 goto done;
 147         }
 148         uap->sysmsg_result = low;
 149         error = 0;
 150 done:
 151         return (error);
 152 }
 153
 154 /*
 155  * Figure out the current lowest nice priority for processes owned
 156  * by the specified user.
 157  */
 158 static
 159 int
 160 getpriority_callback(struct proc *p, void *data)
 161 {
 162         struct getpriority_info *info = data;
 163
 164         lwkt_gettoken_shared(&p->p_token);
 165         if (PRISON_CHECK(curthread->td_ucred, p->p_ucred) &&
 166             p->p_ucred->cr_uid == info->who &&
 167             p->p_nice < info->low) {
 168                 info->low = p->p_nice;
 169         }
 170         lwkt_reltoken(&p->p_token);
 171         return(0);
 172 }
 173
 174 struct setpriority_info {
 175         int prio;
 176         int who;
 177         int error;
 178         int found;
 179 };
 180
 181 static int setpriority_callback(struct proc *p, void *data);
 182
 183 /*
 184  * MPALMOSTSAFE
 185  */
 186 int
 187 sys_setpriority(struct setpriority_args *uap)
 188 {
 189         struct setpriority_info info;
 190         thread_t curtd = curthread;
 191         struct proc *curp = curproc;
 192         struct proc *p;
 193         struct pgrp *pg;
 194         int found = 0, error = 0;
 195
 196         switch (uap->which) {
 197         case PRIO_PROCESS:
 198                 if (uap->who == 0) {
 199                         lwkt_gettoken(&curp->p_token);
 200                         error = donice(curp, uap->prio);
 201                         found++;
 202                         lwkt_reltoken(&curp->p_token);
 203                 } else {
 204                         p = pfind(uap->who);
 205                         if (p) {
 206                                 lwkt_gettoken(&p->p_token);
 207                                 if (PRISON_CHECK(curtd->td_ucred, p->p_ucred)) {
 208                                         error = donice(p, uap->prio);
 209                                         found++;
 210                                 }
 211                                 lwkt_reltoken(&p->p_token);
 212                                 PRELE(p);
 213                         }
 214                 }
 215                 break;
 216         case PRIO_PGRP:
 217                 if (uap->who == 0) {
 218                         lwkt_gettoken_shared(&curp->p_token);
 219                         pg = curp->p_pgrp;
 220                         pgref(pg);
 221                         lwkt_reltoken(&curp->p_token);
 222                 } else if ((pg = pgfind(uap->who)) == NULL) {
 223                         break;
 224                 } /* else ref held from pgfind */
 225
 226                 lwkt_gettoken(&pg->pg_token);
 227 restart:
 228                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
 229                         PHOLD(p);
 230                         lwkt_gettoken(&p->p_token);
 231                         if (p->p_pgrp == pg &&
 232                             PRISON_CHECK(curtd->td_ucred, p->p_ucred)) {
 233                                 error = donice(p, uap->prio);
 234                                 found++;
 235                         }
 236                         lwkt_reltoken(&p->p_token);
 237                         if (p->p_pgrp != pg) {
 238                                 PRELE(p);
 239                                 goto restart;
 240                         }
 241                         PRELE(p);
 242                 }
 243                 lwkt_reltoken(&pg->pg_token);
 244                 pgrel(pg);
 245                 break;
 246         case PRIO_USER:
 247                 if (uap->who == 0)
 248                         uap->who = curtd->td_ucred->cr_uid;
 249                 info.prio = uap->prio;
 250                 info.who = uap->who;
 251                 info.error = 0;
 252                 info.found = 0;
 253                 allproc_scan(setpriority_callback, &info, 0);
 254                 error = info.error;
 255                 found = info.found;
 256                 break;
 257         default:
 258                 error = EINVAL;
 259                 found = 1;
 260                 break;
 261         }
 262
 263         if (found == 0)
 264                 error = ESRCH;
 265         return (error);
 266 }
 267
 268 static
 269 int
 270 setpriority_callback(struct proc *p, void *data)
 271 {
 272         struct setpriority_info *info = data;
 273         int error;
 274
 275         lwkt_gettoken(&p->p_token);
 276         if (p->p_ucred->cr_uid == info->who &&
 277             PRISON_CHECK(curthread->td_ucred, p->p_ucred)) {
 278                 error = donice(p, info->prio);
 279                 if (error)
 280                         info->error = error;
 281                 ++info->found;
 282         }
 283         lwkt_reltoken(&p->p_token);
 284         return(0);
 285 }
 286
 287 /*
 288  * Caller must hold chgp->p_token
 289  */
 290 static int
 291 donice(struct proc *chgp, int n)
 292 {
 293         struct ucred *cr = curthread->td_ucred;
 294         struct lwp *lp;
 295
 296         if (cr->cr_uid && cr->cr_ruid &&
 297             cr->cr_uid != chgp->p_ucred->cr_uid &&
 298             cr->cr_ruid != chgp->p_ucred->cr_uid)
 299                 return (EPERM);
 300         if (n > PRIO_MAX)
 301                 n = PRIO_MAX;
 302         if (n < PRIO_MIN)
 303                 n = PRIO_MIN;
 304         if (n < chgp->p_nice && priv_check_cred(cr, PRIV_SCHED_SETPRIORITY, 0))
 305                 return (EACCES);
 306         chgp->p_nice = n;
 307         FOREACH_LWP_IN_PROC(lp, chgp) {
 308                 LWPHOLD(lp);
 309                 chgp->p_usched->resetpriority(lp);
 310                 LWPRELE(lp);
 311         }
 312         return (0);
 313 }
 314
 315
 316 struct ioprio_get_info {
 317         int high;
 318         int who;
 319 };
 320
 321 static int ioprio_get_callback(struct proc *p, void *data);
 322
 323 /*
 324  * MPALMOSTSAFE
 325  */
 326 int
 327 sys_ioprio_get(struct ioprio_get_args *uap)
 328 {
 329         struct ioprio_get_info info;
 330         thread_t curtd = curthread;
 331         struct proc *curp = curproc;
 332         struct proc *p;
 333         struct pgrp *pg;
 334         int high = IOPRIO_MIN-2;
 335         int error;
 336
 337         switch (uap->which) {
 338         case PRIO_PROCESS:
 339                 if (uap->who == 0) {
 340                         high = curp->p_ionice;
 341                 } else {
 342                         p = pfind(uap->who);
 343                         if (p) {
 344                                 lwkt_gettoken_shared(&p->p_token);
 345                                 if (PRISON_CHECK(curtd->td_ucred, p->p_ucred))
 346                                         high = p->p_ionice;
 347                                 lwkt_reltoken(&p->p_token);
 348                                 PRELE(p);
 349                         }
 350                 }
 351                 break;
 352         case PRIO_PGRP:
 353                 if (uap->who == 0) {
 354                         lwkt_gettoken_shared(&curp->p_token);
 355                         pg = curp->p_pgrp;
 356                         pgref(pg);
 357                         lwkt_reltoken(&curp->p_token);
 358                 } else if ((pg = pgfind(uap->who)) == NULL) {
 359                         break;
 360                 } /* else ref held from pgfind */
 361
 362                 lwkt_gettoken_shared(&pg->pg_token);
 363                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
 364                         if (PRISON_CHECK(curtd->td_ucred, p->p_ucred) &&
 365                             p->p_nice > high)
 366                                 high = p->p_ionice;
 367                 }
 368                 lwkt_reltoken(&pg->pg_token);
 369                 pgrel(pg);
 370                 break;
 371         case PRIO_USER:
 372                 if (uap->who == 0)
 373                         uap->who = curtd->td_ucred->cr_uid;
 374                 info.high = high;
 375                 info.who = uap->who;
 376                 allproc_scan(ioprio_get_callback, &info, 0);
 377                 high = info.high;
 378                 break;
 379         default:
 380                 error = EINVAL;
 381                 goto done;
 382         }
 383         if (high == IOPRIO_MIN-2) {
 384                 error = ESRCH;
 385                 goto done;
 386         }
 387         uap->sysmsg_result = high;
 388         error = 0;
 389 done:
 390         return (error);
 391 }
 392
 393 /*
 394  * Figure out the current lowest nice priority for processes owned
 395  * by the specified user.
 396  */
 397 static
 398 int
 399 ioprio_get_callback(struct proc *p, void *data)
 400 {
 401         struct ioprio_get_info *info = data;
 402
 403         lwkt_gettoken_shared(&p->p_token);
 404         if (PRISON_CHECK(curthread->td_ucred, p->p_ucred) &&
 405             p->p_ucred->cr_uid == info->who &&
 406             p->p_ionice > info->high) {
 407                 info->high = p->p_ionice;
 408         }
 409         lwkt_reltoken(&p->p_token);
 410         return(0);
 411 }
 412
 413
 414 struct ioprio_set_info {
 415         int prio;
 416         int who;
 417         int error;
 418         int found;
 419 };
 420
 421 static int ioprio_set_callback(struct proc *p, void *data);
 422
 423 /*
 424  * MPALMOSTSAFE
 425  */
 426 int
 427 sys_ioprio_set(struct ioprio_set_args *uap)
 428 {
 429         struct ioprio_set_info info;
 430         thread_t curtd = curthread;
 431         struct proc *curp = curproc;
 432         struct proc *p;
 433         struct pgrp *pg;
 434         int found = 0, error = 0;
 435
 436         switch (uap->which) {
 437         case PRIO_PROCESS:
 438                 if (uap->who == 0) {
 439                         lwkt_gettoken(&curp->p_token);
 440                         error = doionice(curp, uap->prio);
 441                         lwkt_reltoken(&curp->p_token);
 442                         found++;
 443                 } else {
 444                         p = pfind(uap->who);
 445                         if (p) {
 446                                 lwkt_gettoken(&p->p_token);
 447                                 if (PRISON_CHECK(curtd->td_ucred, p->p_ucred)) {
 448                                         error = doionice(p, uap->prio);
 449                                         found++;
 450                                 }
 451                                 lwkt_reltoken(&p->p_token);
 452                                 PRELE(p);
 453                         }
 454                 }
 455                 break;
 456         case PRIO_PGRP:
 457                 if (uap->who == 0) {
 458                         lwkt_gettoken_shared(&curp->p_token);
 459                         pg = curp->p_pgrp;
 460                         pgref(pg);
 461                         lwkt_reltoken(&curp->p_token);
 462                 } else if ((pg = pgfind(uap->who)) == NULL) {
 463                         break;
 464                 } /* else ref held from pgfind */
 465
 466                 lwkt_gettoken(&pg->pg_token);
 467 restart:
 468                 LIST_FOREACH(p, &pg->pg_members, p_pglist) {
 469                         PHOLD(p);
 470                         lwkt_gettoken(&p->p_token);
 471                         if (p->p_pgrp == pg &&
 472                             PRISON_CHECK(curtd->td_ucred, p->p_ucred)) {
 473                                 error = doionice(p, uap->prio);
 474                                 found++;
 475                         }
 476                         lwkt_reltoken(&p->p_token);
 477                         if (p->p_pgrp != pg) {
 478                                 PRELE(p);
 479                                 goto restart;
 480                         }
 481                         PRELE(p);
 482                 }
 483                 lwkt_reltoken(&pg->pg_token);
 484                 pgrel(pg);
 485                 break;
 486         case PRIO_USER:
 487                 if (uap->who == 0)
 488                         uap->who = curtd->td_ucred->cr_uid;
 489                 info.prio = uap->prio;
 490                 info.who = uap->who;
 491                 info.error = 0;
 492                 info.found = 0;
 493                 allproc_scan(ioprio_set_callback, &info, 0);
 494                 error = info.error;
 495                 found = info.found;
 496                 break;
 497         default:
 498                 error = EINVAL;
 499                 found = 1;
 500                 break;
 501         }
 502
 503         if (found == 0)
 504                 error = ESRCH;
 505         return (error);
 506 }
 507
 508 static
 509 int
 510 ioprio_set_callback(struct proc *p, void *data)
 511 {
 512         struct ioprio_set_info *info = data;
 513         int error;
 514
 515         lwkt_gettoken(&p->p_token);
 516         if (p->p_ucred->cr_uid == info->who &&
 517             PRISON_CHECK(curthread->td_ucred, p->p_ucred)) {
 518                 error = doionice(p, info->prio);
 519                 if (error)
 520                         info->error = error;
 521                 ++info->found;
 522         }
 523         lwkt_reltoken(&p->p_token);
 524         return(0);
 525 }
 526
 527 static int
 528 doionice(struct proc *chgp, int n)
 529 {
 530         struct ucred *cr = curthread->td_ucred;
 531
 532         if (cr->cr_uid && cr->cr_ruid &&
 533             cr->cr_uid != chgp->p_ucred->cr_uid &&
 534             cr->cr_ruid != chgp->p_ucred->cr_uid)
 535                 return (EPERM);
 536         if (n > IOPRIO_MAX)
 537                 n = IOPRIO_MAX;
 538         if (n < IOPRIO_MIN)
 539                 n = IOPRIO_MIN;
 540         if (n < chgp->p_ionice &&
 541             priv_check_cred(cr, PRIV_SCHED_SETPRIORITY, 0))
 542                 return (EACCES);
 543         chgp->p_ionice = n;
 544
 545         return (0);
 546
 547 }
 548
 549 /*
 550  * MPALMOSTSAFE
 551  */
 552 int
 553 sys_lwp_rtprio(struct lwp_rtprio_args *uap)
 554 {
 555         struct ucred *cr = curthread->td_ucred;
 556         struct proc *p;
 557         struct lwp *lp;
 558         struct rtprio rtp;
 559         int error;
 560
 561         error = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
 562         if (error)
 563                 return error;
 564         if (uap->pid < 0)
 565                 return EINVAL;
 566
 567         if (uap->pid == 0) {
 568                 p = curproc;
 569                 PHOLD(p);
 570         } else {
 571                 p = pfind(uap->pid);
 572         }
 573         if (p == NULL) {
 574                 error = ESRCH;
 575                 goto done;
 576         }
 577         lwkt_gettoken(&p->p_token);
 578
 579         if (uap->tid < -1) {
 580                 error = EINVAL;
 581                 goto done;
 582         }
 583         if (uap->tid == -1) {
 584                 /*
 585                  * sadly, tid can be 0 so we can't use 0 here
 586                  * like sys_rtprio()
 587                  */
 588                 lp = curthread->td_lwp;
 589         } else {
 590                 lp = lwp_rb_tree_RB_LOOKUP(&p->p_lwp_tree, uap->tid);
 591                 if (lp == NULL) {
 592                         error = ESRCH;
 593                         goto done;
 594                 }
 595         }
 596
 597         /*
 598          * Make sure that this lwp is not ripped if any of the following
 599          * code blocks, e.g. copyout.
 600          */
 601         LWPHOLD(lp);
 602         switch (uap->function) {
 603         case RTP_LOOKUP:
 604                 error = copyout(&lp->lwp_rtprio, uap->rtp,
 605                                 sizeof(struct rtprio));
 606                 break;
 607         case RTP_SET:
 608                 if (cr->cr_uid && cr->cr_ruid &&
 609                     cr->cr_uid != p->p_ucred->cr_uid &&
 610                     cr->cr_ruid != p->p_ucred->cr_uid) {
 611                         error = EPERM;
 612                         break;
 613                 }
 614                 /* disallow setting rtprio in most cases if not superuser */
 615                 if (priv_check_cred(cr, PRIV_SCHED_RTPRIO, 0)) {
 616                         /* can't set someone else's */
 617                         if (uap->pid) { /* XXX */
 618                                 error = EPERM;
 619                                 break;
 620                         }
 621                         /* can't set realtime priority */
 622 /*
 623  * Realtime priority has to be restricted for reasons which should be
 624  * obvious. However, for idle priority, there is a potential for
 625  * system deadlock if an idleprio process gains a lock on a resource
 626  * that other processes need (and the idleprio process can't run
 627  * due to a CPU-bound normal process). Fix me! XXX
 628  */
 629                         if (RTP_PRIO_IS_REALTIME(rtp.type)) {
 630                                 error = EPERM;
 631                                 break;
 632                         }
 633                 }
 634                 switch (rtp.type) {
 635 #ifdef RTP_PRIO_FIFO
 636                 case RTP_PRIO_FIFO:
 637 #endif
 638                 case RTP_PRIO_REALTIME:
 639                 case RTP_PRIO_NORMAL:
 640                 case RTP_PRIO_IDLE:
 641                         if (rtp.prio > RTP_PRIO_MAX) {
 642                                 error = EINVAL;
 643                         } else {
 644                                 lp->lwp_rtprio = rtp;
 645                                 error = 0;
 646                         }
 647                         break;
 648                 default:
 649                         error = EINVAL;
 650                         break;
 651                 }
 652                 break;
 653         default:
 654                 error = EINVAL;
 655                 break;
 656         }
 657         LWPRELE(lp);
 658
 659 done:
 660         if (p) {
 661                 lwkt_reltoken(&p->p_token);
 662                 PRELE(p);
 663         }
 664         return (error);
 665 }
 666
 667 /*
 668  * Set realtime priority
 669  *
 670  * MPALMOSTSAFE
 671  */
 672 int
 673 sys_rtprio(struct rtprio_args *uap)
 674 {
 675         struct ucred *cr = curthread->td_ucred;
 676         struct proc *p;
 677         struct lwp *lp;
 678         struct rtprio rtp;
 679         int error;
 680
 681         error = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
 682         if (error)
 683                 return (error);
 684
 685         if (uap->pid == 0) {
 686                 p = curproc;
 687                 PHOLD(p);
 688         } else {
 689                 p = pfind(uap->pid);
 690         }
 691
 692         if (p == NULL) {
 693                 error = ESRCH;
 694                 goto done;
 695         }
 696         lwkt_gettoken(&p->p_token);
 697
 698         /* XXX lwp */
 699         lp = FIRST_LWP_IN_PROC(p);
 700         switch (uap->function) {
 701         case RTP_LOOKUP:
 702                 error = copyout(&lp->lwp_rtprio, uap->rtp,
 703                                 sizeof(struct rtprio));
 704                 break;
 705         case RTP_SET:
 706                 if (cr->cr_uid && cr->cr_ruid &&
 707                     cr->cr_uid != p->p_ucred->cr_uid &&
 708                     cr->cr_ruid != p->p_ucred->cr_uid) {
 709                         error = EPERM;
 710                         break;
 711                 }
 712                 /* disallow setting rtprio in most cases if not superuser */
 713                 if (priv_check_cred(cr, PRIV_SCHED_RTPRIO, 0)) {
 714                         /* can't set someone else's */
 715                         if (uap->pid) {
 716                                 error = EPERM;
 717                                 break;
 718                         }
 719                         /* can't set realtime priority */
 720 /*
 721  * Realtime priority has to be restricted for reasons which should be
 722  * obvious. However, for idle priority, there is a potential for
 723  * system deadlock if an idleprio process gains a lock on a resource
 724  * that other processes need (and the idleprio process can't run
 725  * due to a CPU-bound normal process). Fix me! XXX
 726  */
 727                         if (RTP_PRIO_IS_REALTIME(rtp.type)) {
 728                                 error = EPERM;
 729                                 break;
 730                         }
 731                 }
 732                 switch (rtp.type) {
 733 #ifdef RTP_PRIO_FIFO
 734                 case RTP_PRIO_FIFO:
 735 #endif
 736                 case RTP_PRIO_REALTIME:
 737                 case RTP_PRIO_NORMAL:
 738                 case RTP_PRIO_IDLE:
 739                         if (rtp.prio > RTP_PRIO_MAX) {
 740                                 error = EINVAL;
 741                                 break;
 742                         }
 743                         lp->lwp_rtprio = rtp;
 744                         error = 0;
 745                         break;
 746                 default:
 747                         error = EINVAL;
 748                         break;
 749                 }
 750                 break;
 751         default:
 752                 error = EINVAL;
 753                 break;
 754         }
 755 done:
 756         if (p) {
 757                 lwkt_reltoken(&p->p_token);
 758                 PRELE(p);
 759         }
 760
 761         return (error);
 762 }
 763
 764 int
 765 sys_setrlimit(struct __setrlimit_args *uap)
 766 {
 767         struct rlimit alim;
 768         int error;
 769
 770         error = copyin(uap->rlp, &alim, sizeof(alim));
 771         if (error)
 772                 return (error);
 773
 774         error = kern_setrlimit(uap->which, &alim);
 775
 776         return (error);
 777 }
 778
 779 int
 780 sys_getrlimit(struct __getrlimit_args *uap)
 781 {
 782         struct rlimit lim;
 783         int error;
 784
 785         error = kern_getrlimit(uap->which, &lim);
 786
 787         if (error == 0)
 788                 error = copyout(&lim, uap->rlp, sizeof(*uap->rlp));
 789         return error;
 790 }
 791
 792 /*
 793  * Transform the running time and tick information in lwp lp's thread into user,
 794  * system, and interrupt time usage.
 795  *
 796  * Since we are limited to statclock tick granularity this is a statisical
 797  * calculation which will be correct over the long haul, but should not be
 798  * expected to measure fine grained deltas.
 799  *
 800  * It is possible to catch a lwp in the midst of being created, so
 801  * check whether lwp_thread is NULL or not.
 802  */
 803 void
 804 calcru(struct lwp *lp, struct timeval *up, struct timeval *sp)
 805 {
 806         struct thread *td;
 807
 808         /*
 809          * Calculate at the statclock level.  YYY if the thread is owned by
 810          * another cpu we need to forward the request to the other cpu, or
 811          * have a token to interlock the information in order to avoid racing
 812          * thread destruction.
 813          */
 814         if ((td = lp->lwp_thread) != NULL) {
 815                 crit_enter();
 816                 up->tv_sec = td->td_uticks / 1000000;
 817                 up->tv_usec = td->td_uticks % 1000000;
 818                 sp->tv_sec = td->td_sticks / 1000000;
 819                 sp->tv_usec = td->td_sticks % 1000000;
 820                 crit_exit();
 821         }
 822 }
 823
 824 /*
 825  * Aggregate resource statistics of all lwps of a process.
 826  *
 827  * proc.p_ru keeps track of all statistics directly related to a proc.  This
 828  * consists of RSS usage and nswap information and aggregate numbers for all
 829  * former lwps of this proc.
 830  *
 831  * proc.p_cru is the sum of all stats of reaped children.
 832  *
 833  * lwp.lwp_ru contains the stats directly related to one specific lwp, meaning
 834  * packet, scheduler switch or page fault counts, etc.  This information gets
 835  * added to lwp.lwp_proc.p_ru when the lwp exits.
 836  */
 837 void
 838 calcru_proc(struct proc *p, struct rusage *ru)
 839 {
 840         struct timeval upt, spt;
 841         long *rip1, *rip2;
 842         struct lwp *lp;
 843
 844         *ru = p->p_ru;
 845
 846         FOREACH_LWP_IN_PROC(lp, p) {
 847                 calcru(lp, &upt, &spt);
 848                 timevaladd(&ru->ru_utime, &upt);
 849                 timevaladd(&ru->ru_stime, &spt);
 850                 for (rip1 = &ru->ru_first, rip2 = &lp->lwp_ru.ru_first;
 851                      rip1 <= &ru->ru_last;
 852                      rip1++, rip2++)
 853                         *rip1 += *rip2;
 854         }
 855 }
 856
 857
 858 /*
 859  * MPALMOSTSAFE
 860  */
 861 int
 862 sys_getrusage(struct getrusage_args *uap)
 863 {
 864         struct proc *p = curproc;
 865         struct rusage ru;
 866         struct rusage *rup;
 867         int error;
 868
 869         lwkt_gettoken(&p->p_token);
 870
 871         switch (uap->who) {
 872         case RUSAGE_SELF:
 873                 rup = &ru;
 874                 calcru_proc(p, rup);
 875                 error = 0;
 876                 break;
 877         case RUSAGE_CHILDREN:
 878                 rup = &p->p_cru;
 879                 error = 0;
 880                 break;
 881         default:
 882                 error = EINVAL;
 883                 break;
 884         }
 885         lwkt_reltoken(&p->p_token);
 886
 887         if (error == 0)
 888                 error = copyout(rup, uap->rusage, sizeof(struct rusage));
 889         return (error);
 890 }
 891
 892 void
 893 ruadd(struct rusage *ru, struct rusage *ru2)
 894 {
 895         long *ip, *ip2;
 896         int i;
 897
 898         timevaladd(&ru->ru_utime, &ru2->ru_utime);
 899         timevaladd(&ru->ru_stime, &ru2->ru_stime);
 900         if (ru->ru_maxrss < ru2->ru_maxrss)
 901                 ru->ru_maxrss = ru2->ru_maxrss;
 902         ip = &ru->ru_first; ip2 = &ru2->ru_first;
 903         for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
 904                 *ip++ += *ip2++;
 905 }
 906
 907 /*
 908  * Find the uidinfo structure for a uid.  This structure is used to
 909  * track the total resource consumption (process count, socket buffer
 910  * size, etc.) for the uid and impose limits.
 911  */
 912 void
 913 uihashinit(void)
 914 {
 915         spin_init(&uihash_lock, "uihashinit");
 916         uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
 917 }
 918
 919 /*
 920  * NOTE: Must be called with uihash_lock held
 921  */
 922 static struct uidinfo *
 923 uilookup(uid_t uid)
 924 {
 925         struct  uihashhead *uipp;
 926         struct  uidinfo *uip;
 927
 928         uipp = UIHASH(uid);
 929         LIST_FOREACH(uip, uipp, ui_hash) {
 930                 if (uip->ui_uid == uid)
 931                         break;
 932         }
 933         return (uip);
 934 }
 935
 936 /*
 937  * Helper function to creat ea uid that could not be found.
 938  * This function will properly deal with races.
 939  *
 940  * WARNING! Should only be used by this source file and by the proc0
 941  *          creation code.
 942  */
 943 struct uidinfo *
 944 uicreate(uid_t uid)
 945 {
 946         struct  uidinfo *uip, *tmp;
 947
 948         /*
 949          * Allocate space and check for a race
 950          */
 951         uip = kmalloc(sizeof(*uip), M_UIDINFO, M_WAITOK|M_ZERO);
 952
 953         /*
 954          * Initialize structure and enter it into the hash table
 955          */
 956         spin_init(&uip->ui_lock, "uicreate");
 957         uip->ui_uid = uid;
 958         uip->ui_ref = 1;        /* we're returning a ref */
 959         varsymset_init(&uip->ui_varsymset, NULL);
 960
 961         /*
 962          * Somebody may have already created the uidinfo for this
 963          * uid. If so, return that instead.
 964          */
 965         spin_lock(&uihash_lock);
 966         tmp = uilookup(uid);
 967         if (tmp != NULL) {
 968                 uihold(tmp);
 969                 spin_unlock(&uihash_lock);
 970
 971                 spin_uninit(&uip->ui_lock);
 972                 varsymset_clean(&uip->ui_varsymset);
 973                 kfree(uip, M_UIDINFO);
 974                 uip = tmp;
 975         } else {
 976                 LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
 977                 spin_unlock(&uihash_lock);
 978         }
 979         return (uip);
 980 }
 981
 982 /*
 983  * Find the uidinfo for a uid, creating one if necessary
 984  */
 985 struct uidinfo *
 986 uifind(uid_t uid)
 987 {
 988         struct uidinfo *uip;
 989         thread_t td = curthread;
 990
 991         if (td->td_ucred) {
 992                 uip = td->td_ucred->cr_uidinfo;
 993                 if (uip->ui_uid == uid) {
 994                         uihold(uip);
 995                         return uip;
 996                 }
 997                 uip = td->td_ucred->cr_ruidinfo;
 998                 if (uip->ui_uid == uid) {
 999                         uihold(uip);
1000                         return uip;
1001                 }
1002         }
1003
1004         spin_lock_shared(&uihash_lock);
1005         uip = uilookup(uid);
1006         if (uip == NULL) {
1007                 spin_unlock_shared(&uihash_lock);
1008                 uip = uicreate(uid);
1009         } else {
1010                 uihold(uip);
1011                 spin_unlock_shared(&uihash_lock);
1012         }
1013         return (uip);
1014 }
1015
1016 /*
1017  * Helper funtion to remove a uidinfo whos reference count may
1018  * have transitioned to 0.  The reference count is likely 0
1019  * on-call.
1020  */
1021 static __inline void
1022 uifree(uid_t uid)
1023 {
1024         struct uidinfo *uip;
1025
1026         /*
1027          * If we are still the only holder after acquiring the uihash_lock
1028          * we can safely unlink the uip and destroy it.  Otherwise we lost
1029          * a race and must fail.
1030          */
1031         spin_lock(&uihash_lock);
1032         uip = uilookup(uid);
1033         if (uip && uip->ui_ref == 0) {
1034                 LIST_REMOVE(uip, ui_hash);
1035                 spin_unlock(&uihash_lock);
1036
1037                 /*
1038                  * The uip is now orphaned and we can destroy it at our
1039                  * leisure.
1040                  */
1041                 if (uip->ui_sbsize != 0)
1042                         kprintf("freeing uidinfo: uid = %d, sbsize = %jd\n",
1043                             uip->ui_uid, (intmax_t)uip->ui_sbsize);
1044                 if (uip->ui_proccnt != 0)
1045                         kprintf("freeing uidinfo: uid = %d, proccnt = %ld\n",
1046                             uip->ui_uid, uip->ui_proccnt);
1047
1048                 varsymset_clean(&uip->ui_varsymset);
1049                 lockuninit(&uip->ui_varsymset.vx_lock);
1050                 spin_uninit(&uip->ui_lock);
1051                 kfree(uip, M_UIDINFO);
1052         } else {
1053                 spin_unlock(&uihash_lock);
1054         }
1055 }
1056
1057 /*
1058  * Bump the ref count
1059  */
1060 void
1061 uihold(struct uidinfo *uip)
1062 {
1063         KKASSERT(uip->ui_ref >= 0);
1064         atomic_add_int(&uip->ui_ref, 1);
1065 }
1066
1067 /*
1068  * Drop the ref count.  The last-drop code still needs to remove the
1069  * uidinfo from the hash table which it does by re-looking-it-up.
1070  *
1071  * NOTE: The uip can be ripped out from under us after the fetchadd.
1072  */
1073 void
1074 uidrop(struct uidinfo *uip)
1075 {
1076         uid_t uid;
1077
1078         KKASSERT(uip->ui_ref > 0);
1079         uid = uip->ui_uid;
1080         cpu_ccfence();
1081         if (atomic_fetchadd_int(&uip->ui_ref, -1) == 1) {
1082                 uifree(uid);
1083         }
1084 }
1085
1086 void
1087 uireplace(struct uidinfo **puip, struct uidinfo *nuip)
1088 {
1089         uidrop(*puip);
1090         *puip = nuip;
1091 }
1092
1093 /*
1094  * Change the count associated with number of processes
1095  * a given user is using.
1096  *
1097  * NOTE: When 'max' is 0, don't enforce a limit.
1098  *
1099  * NOTE: Due to concurrency, the count can sometimes exceed the max
1100  *       by a small amount.
1101  */
1102 int
1103 chgproccnt(struct uidinfo *uip, int diff, int max)
1104 {
1105         int ret;
1106
1107         /* don't allow them to exceed max, but allow subtraction */
1108         if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
1109                 ret = 0;
1110         } else {
1111                 atomic_add_long(&uip->ui_proccnt, diff);
1112                 if (uip->ui_proccnt < 0)
1113                         kprintf("negative proccnt for uid = %d\n", uip->ui_uid);
1114                 ret = 1;
1115         }
1116         return ret;
1117 }
1118
1119 /*
1120  * Change the total socket buffer size a user has used.
1121  */
1122 int
1123 chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t max)
1124 {
1125         rlim_t new;
1126
1127         rlim_t sbsize;
1128
1129         sbsize = atomic_fetchadd_long(&uip->ui_sbsize, to - *hiwat);
1130         new = sbsize + to - *hiwat;
1131         KKASSERT(new >= 0);
1132
1133         /*
1134          * If we are trying to increase the socket buffer size
1135          * Scale down the hi water mark when we exceed the user's
1136          * allowed socket buffer space.
1137          *
1138          * We can't scale down too much or we will blow up atomic packet
1139          * operations.
1140          */
1141         if (to > *hiwat && to > MCLBYTES && new > max) {
1142                 to = to * max / new;
1143                 if (to < MCLBYTES)
1144                         to = MCLBYTES;
1145         }
1146         *hiwat = to;
1147         return (1);
1148 }