root/kernel/sys.c

/* */

DEFINITIONS

1. sys_ni_syscall
2. proc_sel
3. sys_setpriority
4. sys_getpriority
5. sys_profil
6. sys_ftime
7. sys_break
8. sys_stty
9. sys_gtty
10. sys_prof
11. sys_reboot
12. ctrl_alt_del
13. sys_setregid
14. sys_setgid
15. sys_acct
16. sys_phys
17. sys_lock
18. sys_mpx
19. sys_ulimit
20. sys_old_syscall
21. sys_setreuid
22. sys_setuid
23. sys_setfsuid
24. sys_setfsgid
25. sys_times
26. sys_brk
27. sys_setpgid
28. sys_getpgid
29. sys_getpgrp
30. sys_setsid
31. sys_getgroups
32. sys_setgroups
33. in_group_p
34. sys_newuname
35. sys_uname
36. sys_olduname
37. sys_sethostname
38. sys_setdomainname
39. sys_getrlimit
40. sys_setrlimit
41. getrusage
42. sys_getrusage
43. sys_umask

   1 /*
   2  *  linux/kernel/sys.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6 
   7 #include <linux/errno.h>
   8 #include <linux/sched.h>
   9 #include <linux/kernel.h>
  10 #include <linux/times.h>
  11 #include <linux/utsname.h>
  12 #include <linux/param.h>
  13 #include <linux/resource.h>
  14 #include <linux/signal.h>
  15 #include <linux/string.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/stat.h>
  18 #include <linux/mman.h>
  19 #include <linux/mm.h>
  20 
  21 #include <asm/segment.h>
  22 #include <asm/io.h>
  23 
  24 /*
  25  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
  26  */
  27 static int C_A_D = 1;
  28 
  29 extern void adjust_clock(void);
  30 
  31 #define PZERO   15
  32 
  33 asmlinkage int sys_ni_syscall(void)
     /*  */
  34 {
  35         return -ENOSYS;
  36 }
  37 
  38 static int proc_sel(struct task_struct *p, int which, int who)
     /*  */
  39 {
  40         switch (which) {
  41                 case PRIO_PROCESS:
  42                         if (!who && p == current)
  43                                 return 1;
  44                         return(p->pid == who);
  45                 case PRIO_PGRP:
  46                         if (!who)
  47                                 who = current->pgrp;
  48                         return(p->pgrp == who);
  49                 case PRIO_USER:
  50                         if (!who)
  51                                 who = current->uid;
  52                         return(p->uid == who);
  53         }
  54         return 0;
  55 }
  56 
  57 asmlinkage int sys_setpriority(int which, int who, int niceval)
     /*  */
  58 {
  59         struct task_struct **p;
  60         int error = ESRCH;
  61         int priority;
  62 
  63         if (which > 2 || which < 0)
  64                 return -EINVAL;
  65 
  66         if ((priority = PZERO - niceval) <= 0)
  67                 priority = 1;
  68 
  69         for(p = &LAST_TASK; p > &FIRST_TASK; --p) {
  70                 if (!*p || !proc_sel(*p, which, who))
  71                         continue;
  72                 if ((*p)->uid != current->euid &&
  73                         (*p)->uid != current->uid && !suser()) {
  74                         error = EPERM;
  75                         continue;
  76                 }
  77                 if (error == ESRCH)
  78                         error = 0;
  79                 if (priority > (*p)->priority && !suser())
  80                         error = EACCES;
  81                 else
  82                         (*p)->priority = priority;
  83         }
  84         return -error;
  85 }
  86 
  87 asmlinkage int sys_getpriority(int which, int who)
     /*  */
  88 {
  89         struct task_struct **p;
  90         int max_prio = 0;
  91 
  92         if (which > 2 || which < 0)
  93                 return -EINVAL;
  94 
  95         for(p = &LAST_TASK; p > &FIRST_TASK; --p) {
  96                 if (!*p || !proc_sel(*p, which, who))
  97                         continue;
  98                 if ((*p)->priority > max_prio)
  99                         max_prio = (*p)->priority;
 100         }
 101         return(max_prio ? max_prio : -ESRCH);
 102 }
 103 
 104 asmlinkage int sys_profil(void)
     /*  */
 105 {
 106         return -ENOSYS;
 107 }
 108 
 109 asmlinkage int sys_ftime(void)
     /*  */
 110 {
 111         return -ENOSYS;
 112 }
 113 
 114 asmlinkage int sys_break(void)
     /*  */
 115 {
 116         return -ENOSYS;
 117 }
 118 
 119 asmlinkage int sys_stty(void)
     /*  */
 120 {
 121         return -ENOSYS;
 122 }
 123 
 124 asmlinkage int sys_gtty(void)
     /*  */
 125 {
 126         return -ENOSYS;
 127 }
 128 
 129 asmlinkage int sys_prof(void)
     /*  */
 130 {
 131         return -ENOSYS;
 132 }
 133 
 134 extern void hard_reset_now(void);
 135 extern asmlinkage sys_kill(int, int);
 136 
 137 /*
 138  * Reboot system call: for obvious reasons only root may call it,
 139  * and even root needs to set up some magic numbers in the registers
 140  * so that some mistake won't make this reboot the whole machine.
 141  * You can also set the meaning of the ctrl-alt-del-key here.
 142  *
 143  * reboot doesn't sync: do that yourself before calling this.
 144  */
 145 asmlinkage int sys_reboot(int magic, int magic_too, int flag)
     /*  */
 146 {
 147         if (!suser())
 148                 return -EPERM;
 149         if (magic != 0xfee1dead || magic_too != 672274793)
 150                 return -EINVAL;
 151         if (flag == 0x01234567)
 152                 hard_reset_now();
 153         else if (flag == 0x89ABCDEF)
 154                 C_A_D = 1;
 155         else if (!flag)
 156                 C_A_D = 0;
 157         else if (flag == 0xCDEF0123) {
 158                 printk(KERN_EMERG "System halted\n");
 159                 sys_kill(-1, SIGKILL);
 160                 do_exit(0);
 161         } else
 162                 return -EINVAL;
 163         return (0);
 164 }
 165 
 166 /*
 167  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 168  * As it's called within an interrupt, it may NOT sync: the only choice
 169  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 170  */
 171 void ctrl_alt_del(void)
     /*  */
 172 {
 173         if (C_A_D)
 174                 hard_reset_now();
 175         else {
 176                 int i;
 177                 send_sig(SIGINT,task[1],1);
 178                 for (i = 2; i < NR_TASKS; i++)
 179                         send_sig(SIGHUP,task[i],1);
 180         }
 181 }
 182         
 183 
 184 /*
 185  * Unprivileged users may change the real gid to the effective gid
 186  * or vice versa.  (BSD-style)
 187  *
 188  * If you set the real gid at all, or set the effective gid to a value not
 189  * equal to the real gid, then the saved gid is set to the new effective gid.
 190  *
 191  * This makes it possible for a setgid program to completely drop its
 192  * privileges, which is often a useful assertion to make when you are doing
 193  * a security audit over a program.
 194  *
 195  * The general idea is that a program which uses just setregid() will be
 196  * 100% compatible with BSD.  A program which uses just setgid() will be
 197  * 100% compatible with POSIX w/ Saved ID's. 
 198  */
 199 asmlinkage int sys_setregid(gid_t rgid, gid_t egid)
     /*  */
 200 {
 201         int old_rgid = current->gid;
 202 
 203         if (rgid != (gid_t) -1) {
 204                 if ((old_rgid == rgid) ||
 205                     (current->egid==rgid) ||
 206                     suser())
 207                         current->gid = rgid;
 208                 else
 209                         return(-EPERM);
 210         }
 211         if (egid != (gid_t) -1) {
 212                 if ((old_rgid == egid) ||
 213                     (current->egid == egid) ||
 214                     (current->sgid == egid) ||
 215                     suser())
 216                         current->egid = egid;
 217                 else {
 218                         current->gid = old_rgid;
 219                         return(-EPERM);
 220                 }
 221         }
 222         if (rgid != (gid_t) -1 ||
 223             (egid != (gid_t) -1 && egid != old_rgid))
 224                 current->sgid = current->egid;
 225         current->fsgid = current->egid;
 226         return 0;
 227 }
 228 
 229 /*
 230  * setgid() is implemented like SysV w/ SAVED_IDS 
 231  */
 232 asmlinkage int sys_setgid(gid_t gid)
     /*  */
 233 {
 234         if (suser())
 235                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 236         else if ((gid == current->gid) || (gid == current->sgid))
 237                 current->egid = current->fsgid = gid;
 238         else
 239                 return -EPERM;
 240         return 0;
 241 }
 242 
 243 asmlinkage int sys_acct(void)
     /*  */
 244 {
 245         return -ENOSYS;
 246 }
 247 
 248 asmlinkage int sys_phys(void)
     /*  */
 249 {
 250         return -ENOSYS;
 251 }
 252 
 253 asmlinkage int sys_lock(void)
     /*  */
 254 {
 255         return -ENOSYS;
 256 }
 257 
 258 asmlinkage int sys_mpx(void)
     /*  */
 259 {
 260         return -ENOSYS;
 261 }
 262 
 263 asmlinkage int sys_ulimit(void)
     /*  */
 264 {
 265         return -ENOSYS;
 266 }
 267 
 268 asmlinkage int sys_old_syscall(void)
     /*  */
 269 {
 270         return -ENOSYS;
 271 }
 272 
 273 /*
 274  * Unprivileged users may change the real uid to the effective uid
 275  * or vice versa.  (BSD-style)
 276  *
 277  * If you set the real uid at all, or set the effective uid to a value not
 278  * equal to the real uid, then the saved uid is set to the new effective uid.
 279  *
 280  * This makes it possible for a setuid program to completely drop its
 281  * privileges, which is often a useful assertion to make when you are doing
 282  * a security audit over a program.
 283  *
 284  * The general idea is that a program which uses just setreuid() will be
 285  * 100% compatible with BSD.  A program which uses just setuid() will be
 286  * 100% compatible with POSIX w/ Saved ID's. 
 287  */
 288 asmlinkage int sys_setreuid(uid_t ruid, uid_t euid)
     /*  */
 289 {
 290         int old_ruid = current->uid;
 291 
 292         if (ruid != (uid_t) -1) {
 293                 if ((old_ruid == ruid) || 
 294                     (current->euid==ruid) ||
 295                     suser())
 296                         current->uid = ruid;
 297                 else
 298                         return(-EPERM);
 299         }
 300         if (euid != (uid_t) -1) {
 301                 if ((old_ruid == euid) ||
 302                     (current->euid == euid) ||
 303                     (current->suid == euid) ||
 304                     suser())
 305                         current->euid = euid;
 306                 else {
 307                         current->uid = old_ruid;
 308                         return(-EPERM);
 309                 }
 310         }
 311         if (ruid != (uid_t) -1 ||
 312             (euid != (uid_t) -1 && euid != old_ruid))
 313                 current->suid = current->euid;
 314         current->fsuid = current->euid;
 315         return 0;
 316 }
 317 
 318 /*
 319  * setuid() is implemented like SysV w/ SAVED_IDS 
 320  * 
 321  * Note that SAVED_ID's is deficient in that a setuid root program
 322  * like sendmail, for example, cannot set its uid to be a normal 
 323  * user and then switch back, because if you're root, setuid() sets
 324  * the saved uid too.  If you don't like this, blame the bright people
 325  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 326  * will allow a root program to temporarily drop privileges and be able to
 327  * regain them by swapping the real and effective uid.  
 328  */
 329 asmlinkage int sys_setuid(uid_t uid)
     /*  */
 330 {
 331         if (suser())
 332                 current->uid = current->euid = current->suid = current->fsuid = uid;
 333         else if ((uid == current->uid) || (uid == current->suid))
 334                 current->fsuid = current->euid = uid;
 335         else
 336                 return -EPERM;
 337         return(0);
 338 }
 339 
 340 /*
 341  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 342  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 343  * whatever uid it wants to). It normally shadows "euid", except when
 344  * explicitly set by setfsuid() or for access..
 345  */
 346 asmlinkage int sys_setfsuid(uid_t uid)
     /*  */
 347 {
 348         int old_fsuid = current->fsuid;
 349 
 350         if (uid == current->uid || uid == current->euid ||
 351             uid == current->suid || uid == current->fsuid || suser())
 352                 current->fsuid = uid;
 353         return old_fsuid;
 354 }
 355 
 356 /*
 357  * Samma på svenska..
 358  */
 359 asmlinkage int sys_setfsgid(gid_t gid)
     /*  */
 360 {
 361         int old_fsgid = current->fsgid;
 362 
 363         if (gid == current->gid || gid == current->egid ||
 364             gid == current->sgid || gid == current->fsgid || suser())
 365                 current->fsgid = gid;
 366         return old_fsgid;
 367 }
 368 
 369 asmlinkage int sys_times(struct tms * tbuf)
     /*  */
 370 {
 371         if (tbuf) {
 372                 int error = verify_area(VERIFY_WRITE,tbuf,sizeof *tbuf);
 373                 if (error)
 374                         return error;
 375                 put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime);
 376                 put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime);
 377                 put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime);
 378                 put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime);
 379         }
 380         return jiffies;
 381 }
 382 
 383 asmlinkage int sys_brk(unsigned long brk)
     /*  */
 384 {
 385         int freepages;
 386         unsigned long rlim;
 387         unsigned long newbrk, oldbrk;
 388 
 389         if (brk < current->mm->end_code)
 390                 return current->mm->brk;
 391         newbrk = PAGE_ALIGN(brk);
 392         oldbrk = PAGE_ALIGN(current->mm->brk);
 393         if (oldbrk == newbrk)
 394                 return current->mm->brk = brk;
 395 
 396         /*
 397          * Always allow shrinking brk
 398          */
 399         if (brk <= current->mm->brk) {
 400                 current->mm->brk = brk;
 401                 do_munmap(newbrk, oldbrk-newbrk);
 402                 return brk;
 403         }
 404         /*
 405          * Check against rlimit and stack..
 406          */
 407         rlim = current->rlim[RLIMIT_DATA].rlim_cur;
 408         if (rlim >= RLIM_INFINITY)
 409                 rlim = ~0;
 410         if (brk - current->mm->end_code > rlim ||
 411             brk >= current->mm->start_stack - 16384)
 412                 return current->mm->brk;
 413         /*
 414          * Check against existing mmap mappings.
 415          */
 416         if (find_vma_intersection(current, oldbrk, newbrk))
 417                 return current->mm->brk;
 418         /*
 419          * stupid algorithm to decide if we have enough memory: while
 420          * simple, it hopefully works in most obvious cases.. Easy to
 421          * fool it, but this should catch most mistakes.
 422          */
 423         freepages = buffermem >> 12;
 424         freepages += nr_free_pages;
 425         freepages += nr_swap_pages;
 426         freepages -= (high_memory - 0x100000) >> 16;
 427         freepages -= (newbrk-oldbrk) >> 12;
 428         if (freepages < 0)
 429                 return current->mm->brk;
 430 #if 0
 431         freepages += current->mm->rss;
 432         freepages -= oldbrk >> 12;
 433         if (freepages < 0)
 434                 return current->mm->brk;
 435 #endif
 436         /*
 437          * Ok, we have probably got enough memory - let it rip.
 438          */
 439         current->mm->brk = brk;
 440         do_mmap(NULL, oldbrk, newbrk-oldbrk,
 441                 PROT_READ|PROT_WRITE|PROT_EXEC,
 442                 MAP_FIXED|MAP_PRIVATE, 0);
 443         return brk;
 444 }
 445 
 446 /*
 447  * This needs some heave checking ...
 448  * I just haven't get the stomach for it. I also don't fully
 449  * understand sessions/pgrp etc. Let somebody who does explain it.
 450  *
 451  * OK, I think I have the protection semantics right.... this is really
 452  * only important on a multi-user system anyway, to make sure one user
 453  * can't send a signal to a process owned by another.  -TYT, 12/12/91
 454  *
 455  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 456  * LBT 04.03.94
 457  */
 458 asmlinkage int sys_setpgid(pid_t pid, pid_t pgid)
     /*  */
 459 {
 460         struct task_struct * p;
 461 
 462         if (!pid)
 463                 pid = current->pid;
 464         if (!pgid)
 465                 pgid = pid;
 466         if (pgid < 0)
 467                 return -EINVAL;
 468         for_each_task(p) {
 469                 if (p->pid == pid)
 470                         goto found_task;
 471         }
 472         return -ESRCH;
 473 
 474 found_task:
 475         if (p->p_pptr == current || p->p_opptr == current) {
 476                 if (p->session != current->session)
 477                         return -EPERM;
 478                 if (p->did_exec)
 479                         return -EACCES;
 480         } else if (p != current)
 481                 return -ESRCH;
 482         if (p->leader)
 483                 return -EPERM;
 484         if (pgid != pid) {
 485                 struct task_struct * tmp;
 486                 for_each_task (tmp) {
 487                         if (tmp->pgrp == pgid &&
 488                          tmp->session == current->session)
 489                                 goto ok_pgid;
 490                 }
 491                 return -EPERM;
 492         }
 493 
 494 ok_pgid:
 495         p->pgrp = pgid;
 496         return 0;
 497 }
 498 
 499 asmlinkage int sys_getpgid(pid_t pid)
     /*  */
 500 {
 501         struct task_struct * p;
 502 
 503         if (!pid)
 504                 return current->pgrp;
 505         for_each_task(p) {
 506                 if (p->pid == pid)
 507                         return p->pgrp;
 508         }
 509         return -ESRCH;
 510 }
 511 
 512 asmlinkage int sys_getpgrp(void)
     /*  */
 513 {
 514         return current->pgrp;
 515 }
 516 
 517 asmlinkage int sys_setsid(void)
     /*  */
 518 {
 519         if (current->leader)
 520                 return -EPERM;
 521         current->leader = 1;
 522         current->session = current->pgrp = current->pid;
 523         current->tty = NULL;
 524         current->tty_old_pgrp = 0;
 525         return current->pgrp;
 526 }
 527 
 528 /*
 529  * Supplementary group ID's
 530  */
 531 asmlinkage int sys_getgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 532 {
 533         int i;
 534 
 535         if (gidsetsize) {
 536                 i = verify_area(VERIFY_WRITE, grouplist, sizeof(gid_t) * gidsetsize);
 537                 if (i)
 538                         return i;
 539         }
 540         for (i = 0 ; (i < NGROUPS) && (current->groups[i] != NOGROUP) ; i++) {
 541                 if (!gidsetsize)
 542                         continue;
 543                 if (i >= gidsetsize)
 544                         break;
 545                 put_fs_word(current->groups[i], (short *) grouplist);
 546                 grouplist++;
 547         }
 548         return(i);
 549 }
 550 
 551 asmlinkage int sys_setgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 552 {
 553         int     i;
 554 
 555         if (!suser())
 556                 return -EPERM;
 557         if (gidsetsize > NGROUPS)
 558                 return -EINVAL;
 559         for (i = 0; i < gidsetsize; i++, grouplist++) {
 560                 current->groups[i] = get_fs_word((unsigned short *) grouplist);
 561         }
 562         if (i < NGROUPS)
 563                 current->groups[i] = NOGROUP;
 564         return 0;
 565 }
 566 
 567 int in_group_p(gid_t grp)
     /*  */
 568 {
 569         int     i;
 570 
 571         if (grp == current->fsgid)
 572                 return 1;
 573 
 574         for (i = 0; i < NGROUPS; i++) {
 575                 if (current->groups[i] == NOGROUP)
 576                         break;
 577                 if (current->groups[i] == grp)
 578                         return 1;
 579         }
 580         return 0;
 581 }
 582 
 583 asmlinkage int sys_newuname(struct new_utsname * name)
     /*  */
 584 {
 585         int error;
 586 
 587         if (!name)
 588                 return -EFAULT;
 589         error = verify_area(VERIFY_WRITE, name, sizeof *name);
 590         if (!error)
 591                 memcpy_tofs(name,&system_utsname,sizeof *name);
 592         return error;
 593 }
 594 
 595 asmlinkage int sys_uname(struct old_utsname * name)
     /*  */
 596 {
 597         int error;
 598         if (!name)
 599                 return -EFAULT;
 600         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 601         if (error)
 602                 return error;
 603         memcpy_tofs(&name->sysname,&system_utsname.sysname,
 604                 sizeof (system_utsname.sysname));
 605         memcpy_tofs(&name->nodename,&system_utsname.nodename,
 606                 sizeof (system_utsname.nodename));
 607         memcpy_tofs(&name->release,&system_utsname.release,
 608                 sizeof (system_utsname.release));
 609         memcpy_tofs(&name->version,&system_utsname.version,
 610                 sizeof (system_utsname.version));
 611         memcpy_tofs(&name->machine,&system_utsname.machine,
 612                 sizeof (system_utsname.machine));
 613         return 0;
 614 }
 615 
 616 asmlinkage int sys_olduname(struct oldold_utsname * name)
     /*  */
 617 {
 618         int error;
 619         if (!name)
 620                 return -EFAULT;
 621         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 622         if (error)
 623                 return error;
 624         memcpy_tofs(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 625         put_fs_byte(0,name->sysname+__OLD_UTS_LEN);
 626         memcpy_tofs(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 627         put_fs_byte(0,name->nodename+__OLD_UTS_LEN);
 628         memcpy_tofs(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 629         put_fs_byte(0,name->release+__OLD_UTS_LEN);
 630         memcpy_tofs(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 631         put_fs_byte(0,name->version+__OLD_UTS_LEN);
 632         memcpy_tofs(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 633         put_fs_byte(0,name->machine+__OLD_UTS_LEN);
 634         return 0;
 635 }
 636 
 637 /*
 638  * Only sethostname; gethostname can be implemented by calling uname()
 639  */
 640 asmlinkage int sys_sethostname(char *name, int len)
     /*  */
 641 {
 642         int     i;
 643         
 644         if (!suser())
 645                 return -EPERM;
 646         if (len > __NEW_UTS_LEN)
 647                 return -EINVAL;
 648         for (i=0; i < len; i++) {
 649                 if ((system_utsname.nodename[i] = get_fs_byte(name+i)) == 0)
 650                         return 0;
 651         }
 652         system_utsname.nodename[i] = 0;
 653         return 0;
 654 }
 655 
 656 /*
 657  * Only setdomainname; getdomainname can be implemented by calling
 658  * uname()
 659  */
 660 asmlinkage int sys_setdomainname(char *name, int len)
     /*  */
 661 {
 662         int     i;
 663         
 664         if (!suser())
 665                 return -EPERM;
 666         if (len > __NEW_UTS_LEN)
 667                 return -EINVAL;
 668         for (i=0; i < len; i++) {
 669                 if ((system_utsname.domainname[i] = get_fs_byte(name+i)) == 0)
 670                         return 0;
 671         }
 672         system_utsname.domainname[i] = 0;
 673         return 0;
 674 }
 675 
 676 asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 677 {
 678         int error;
 679 
 680         if (resource >= RLIM_NLIMITS)
 681                 return -EINVAL;
 682         error = verify_area(VERIFY_WRITE,rlim,sizeof *rlim);
 683         if (error)
 684                 return error;
 685         put_fs_long(current->rlim[resource].rlim_cur, 
 686                     (unsigned long *) rlim);
 687         put_fs_long(current->rlim[resource].rlim_max, 
 688                     ((unsigned long *) rlim)+1);
 689         return 0;       
 690 }
 691 
 692 asmlinkage int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 693 {
 694         struct rlimit new_rlim, *old_rlim;
 695         int err;
 696 
 697         if (resource >= RLIM_NLIMITS)
 698                 return -EINVAL;
 699         err = verify_area(VERIFY_READ, rlim, sizeof(*rlim));
 700         if (err)
 701                 return err;
 702         memcpy_fromfs(&new_rlim, rlim, sizeof(*rlim));
 703         old_rlim = current->rlim + resource;
 704         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
 705              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
 706             !suser())
 707                 return -EPERM;
 708         if (resource == RLIMIT_NOFILE) {
 709                 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
 710                         return -EPERM;
 711         }
 712         *old_rlim = new_rlim;
 713         return 0;
 714 }
 715 
 716 /*
 717  * It would make sense to put struct rusage in the task_struct,
 718  * except that would make the task_struct be *really big*.  After
 719  * task_struct gets moved into malloc'ed memory, it would
 720  * make sense to do this.  It will make moving the rest of the information
 721  * a lot simpler!  (Which we're not doing right now because we're not
 722  * measuring them yet).
 723  */
 724 int getrusage(struct task_struct *p, int who, struct rusage *ru)
     /*  */
 725 {
 726         int error;
 727         struct rusage r;
 728 
 729         error = verify_area(VERIFY_WRITE, ru, sizeof *ru);
 730         if (error)
 731                 return error;
 732         memset((char *) &r, 0, sizeof(r));
 733         switch (who) {
 734                 case RUSAGE_SELF:
 735                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime);
 736                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime);
 737                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime);
 738                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime);
 739                         r.ru_minflt = p->mm->min_flt;
 740                         r.ru_majflt = p->mm->maj_flt;
 741                         break;
 742                 case RUSAGE_CHILDREN:
 743                         r.ru_utime.tv_sec = CT_TO_SECS(p->cutime);
 744                         r.ru_utime.tv_usec = CT_TO_USECS(p->cutime);
 745                         r.ru_stime.tv_sec = CT_TO_SECS(p->cstime);
 746                         r.ru_stime.tv_usec = CT_TO_USECS(p->cstime);
 747                         r.ru_minflt = p->mm->cmin_flt;
 748                         r.ru_majflt = p->mm->cmaj_flt;
 749                         break;
 750                 default:
 751                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime + p->cutime);
 752                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime + p->cutime);
 753                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime + p->cstime);
 754                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime + p->cstime);
 755                         r.ru_minflt = p->mm->min_flt + p->mm->cmin_flt;
 756                         r.ru_majflt = p->mm->maj_flt + p->mm->cmaj_flt;
 757                         break;
 758         }
 759         memcpy_tofs(ru, &r, sizeof(r));
 760         return 0;
 761 }
 762 
 763 asmlinkage int sys_getrusage(int who, struct rusage *ru)
     /*  */
 764 {
 765         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
 766                 return -EINVAL;
 767         return getrusage(current, who, ru);
 768 }
 769 
 770 asmlinkage int sys_umask(int mask)
     /*  */
 771 {
 772         int old = current->fs->umask;
 773 
 774         current->fs->umask = mask & S_IRWXUGO;
 775         return (old);
 776 }

/* */