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_gethostname
39. sys_setdomainname
40. sys_getrlimit
41. sys_setrlimit
42. getrusage
43. sys_getrusage
44. 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                 send_sig(SIGINT,task[1],1);
 177 }
 178         
 179 
 180 /*
 181  * Unprivileged users may change the real gid to the effective gid
 182  * or vice versa.  (BSD-style)
 183  *
 184  * If you set the real gid at all, or set the effective gid to a value not
 185  * equal to the real gid, then the saved gid is set to the new effective gid.
 186  *
 187  * This makes it possible for a setgid program to completely drop its
 188  * privileges, which is often a useful assertion to make when you are doing
 189  * a security audit over a program.
 190  *
 191  * The general idea is that a program which uses just setregid() will be
 192  * 100% compatible with BSD.  A program which uses just setgid() will be
 193  * 100% compatible with POSIX w/ Saved ID's. 
 194  */
 195 asmlinkage int sys_setregid(gid_t rgid, gid_t egid)
     /*  */
 196 {
 197         int old_rgid = current->gid;
 198         int old_egid = current->egid;
 199 
 200         if (rgid != (gid_t) -1) {
 201                 if ((old_rgid == rgid) ||
 202                     (current->egid==rgid) ||
 203                     suser())
 204                         current->gid = rgid;
 205                 else
 206                         return(-EPERM);
 207         }
 208         if (egid != (gid_t) -1) {
 209                 if ((old_rgid == egid) ||
 210                     (current->egid == egid) ||
 211                     (current->sgid == egid) ||
 212                     suser())
 213                         current->egid = egid;
 214                 else {
 215                         current->gid = old_rgid;
 216                         return(-EPERM);
 217                 }
 218         }
 219         if (rgid != (gid_t) -1 ||
 220             (egid != (gid_t) -1 && egid != old_rgid))
 221                 current->sgid = current->egid;
 222         current->fsgid = current->egid;
 223         if (current->egid != old_egid)
 224                 current->dumpable = 0;
 225         return 0;
 226 }
 227 
 228 /*
 229  * setgid() is implemented like SysV w/ SAVED_IDS 
 230  */
 231 asmlinkage int sys_setgid(gid_t gid)
     /*  */
 232 {
 233         int old_egid = current->egid;
 234 
 235         if (suser())
 236                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 237         else if ((gid == current->gid) || (gid == current->sgid))
 238                 current->egid = current->fsgid = gid;
 239         else
 240                 return -EPERM;
 241         if (current->egid != old_egid)
 242                 current->dumpable = 0;
 243         return 0;
 244 }
 245 
 246 asmlinkage int sys_acct(void)
     /*  */
 247 {
 248         return -ENOSYS;
 249 }
 250 
 251 asmlinkage int sys_phys(void)
     /*  */
 252 {
 253         return -ENOSYS;
 254 }
 255 
 256 asmlinkage int sys_lock(void)
     /*  */
 257 {
 258         return -ENOSYS;
 259 }
 260 
 261 asmlinkage int sys_mpx(void)
     /*  */
 262 {
 263         return -ENOSYS;
 264 }
 265 
 266 asmlinkage int sys_ulimit(void)
     /*  */
 267 {
 268         return -ENOSYS;
 269 }
 270 
 271 asmlinkage int sys_old_syscall(void)
     /*  */
 272 {
 273         return -ENOSYS;
 274 }
 275 
 276 /*
 277  * Unprivileged users may change the real uid to the effective uid
 278  * or vice versa.  (BSD-style)
 279  *
 280  * If you set the real uid at all, or set the effective uid to a value not
 281  * equal to the real uid, then the saved uid is set to the new effective uid.
 282  *
 283  * This makes it possible for a setuid program to completely drop its
 284  * privileges, which is often a useful assertion to make when you are doing
 285  * a security audit over a program.
 286  *
 287  * The general idea is that a program which uses just setreuid() will be
 288  * 100% compatible with BSD.  A program which uses just setuid() will be
 289  * 100% compatible with POSIX w/ Saved ID's. 
 290  */
 291 asmlinkage int sys_setreuid(uid_t ruid, uid_t euid)
     /*  */
 292 {
 293         int old_ruid = current->uid;
 294         int old_euid = current->euid;
 295 
 296         if (ruid != (uid_t) -1) {
 297                 if ((old_ruid == ruid) || 
 298                     (current->euid==ruid) ||
 299                     suser())
 300                         current->uid = ruid;
 301                 else
 302                         return(-EPERM);
 303         }
 304         if (euid != (uid_t) -1) {
 305                 if ((old_ruid == euid) ||
 306                     (current->euid == euid) ||
 307                     (current->suid == euid) ||
 308                     suser())
 309                         current->euid = euid;
 310                 else {
 311                         current->uid = old_ruid;
 312                         return(-EPERM);
 313                 }
 314         }
 315         if (ruid != (uid_t) -1 ||
 316             (euid != (uid_t) -1 && euid != old_ruid))
 317                 current->suid = current->euid;
 318         current->fsuid = current->euid;
 319         if (current->euid != old_euid)
 320                 current->dumpable = 0;
 321         return 0;
 322 }
 323 
 324 /*
 325  * setuid() is implemented like SysV w/ SAVED_IDS 
 326  * 
 327  * Note that SAVED_ID's is deficient in that a setuid root program
 328  * like sendmail, for example, cannot set its uid to be a normal 
 329  * user and then switch back, because if you're root, setuid() sets
 330  * the saved uid too.  If you don't like this, blame the bright people
 331  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 332  * will allow a root program to temporarily drop privileges and be able to
 333  * regain them by swapping the real and effective uid.  
 334  */
 335 asmlinkage int sys_setuid(uid_t uid)
     /*  */
 336 {
 337         int old_euid = current->euid;
 338 
 339         if (suser())
 340                 current->uid = current->euid = current->suid = current->fsuid = uid;
 341         else if ((uid == current->uid) || (uid == current->suid))
 342                 current->fsuid = current->euid = uid;
 343         else
 344                 return -EPERM;
 345         if (current->euid != old_euid)
 346                 current->dumpable = 0;
 347         return(0);
 348 }
 349 
 350 /*
 351  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 352  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 353  * whatever uid it wants to). It normally shadows "euid", except when
 354  * explicitly set by setfsuid() or for access..
 355  */
 356 asmlinkage int sys_setfsuid(uid_t uid)
     /*  */
 357 {
 358         int old_fsuid = current->fsuid;
 359 
 360         if (uid == current->uid || uid == current->euid ||
 361             uid == current->suid || uid == current->fsuid || suser())
 362                 current->fsuid = uid;
 363         if (current->fsuid != old_fsuid)
 364                 current->dumpable = 0;
 365         return old_fsuid;
 366 }
 367 
 368 /*
 369  * Samma på svenska..
 370  */
 371 asmlinkage int sys_setfsgid(gid_t gid)
     /*  */
 372 {
 373         int old_fsgid = current->fsgid;
 374 
 375         if (gid == current->gid || gid == current->egid ||
 376             gid == current->sgid || gid == current->fsgid || suser())
 377                 current->fsgid = gid;
 378         if (current->fsgid != old_fsgid)
 379                 current->dumpable = 0;
 380         return old_fsgid;
 381 }
 382 
 383 asmlinkage int sys_times(struct tms * tbuf)
     /*  */
 384 {
 385         if (tbuf) {
 386                 int error = verify_area(VERIFY_WRITE,tbuf,sizeof *tbuf);
 387                 if (error)
 388                         return error;
 389                 put_user(current->utime,&tbuf->tms_utime);
 390                 put_user(current->stime,&tbuf->tms_stime);
 391                 put_user(current->cutime,&tbuf->tms_cutime);
 392                 put_user(current->cstime,&tbuf->tms_cstime);
 393         }
 394         return jiffies;
 395 }
 396 
 397 asmlinkage unsigned long sys_brk(unsigned long brk)
     /*  */
 398 {
 399         int freepages;
 400         unsigned long rlim;
 401         unsigned long newbrk, oldbrk;
 402 
 403         if (brk < current->mm->end_code)
 404                 return current->mm->brk;
 405         newbrk = PAGE_ALIGN(brk);
 406         oldbrk = PAGE_ALIGN(current->mm->brk);
 407         if (oldbrk == newbrk)
 408                 return current->mm->brk = brk;
 409 
 410         /*
 411          * Always allow shrinking brk
 412          */
 413         if (brk <= current->mm->brk) {
 414                 current->mm->brk = brk;
 415                 do_munmap(newbrk, oldbrk-newbrk);
 416                 return brk;
 417         }
 418         /*
 419          * Check against rlimit and stack..
 420          */
 421         rlim = current->rlim[RLIMIT_DATA].rlim_cur;
 422         if (rlim >= RLIM_INFINITY)
 423                 rlim = ~0;
 424         if (brk - current->mm->end_code > rlim)
 425                 return current->mm->brk;
 426         /*
 427          * Check against existing mmap mappings.
 428          */
 429         if (find_vma_intersection(current, oldbrk, newbrk+PAGE_SIZE))
 430                 return current->mm->brk;
 431         /*
 432          * stupid algorithm to decide if we have enough memory: while
 433          * simple, it hopefully works in most obvious cases.. Easy to
 434          * fool it, but this should catch most mistakes.
 435          */
 436         freepages = buffermem >> 12;
 437         freepages += nr_free_pages;
 438         freepages += nr_swap_pages;
 439         freepages -= (high_memory - 0x100000) >> 16;
 440         freepages -= (newbrk-oldbrk) >> 12;
 441         if (freepages < 0)
 442                 return current->mm->brk;
 443 #if 0
 444         freepages += current->mm->rss;
 445         freepages -= oldbrk >> 12;
 446         if (freepages < 0)
 447                 return current->mm->brk;
 448 #endif
 449         /*
 450          * Ok, we have probably got enough memory - let it rip.
 451          */
 452         current->mm->brk = brk;
 453         do_mmap(NULL, oldbrk, newbrk-oldbrk,
 454                 PROT_READ|PROT_WRITE|PROT_EXEC,
 455                 MAP_FIXED|MAP_PRIVATE, 0);
 456         return brk;
 457 }
 458 
 459 /*
 460  * This needs some heavy checking ...
 461  * I just haven't the stomach for it. I also don't fully
 462  * understand sessions/pgrp etc. Let somebody who does explain it.
 463  *
 464  * OK, I think I have the protection semantics right.... this is really
 465  * only important on a multi-user system anyway, to make sure one user
 466  * can't send a signal to a process owned by another.  -TYT, 12/12/91
 467  *
 468  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 469  * LBT 04.03.94
 470  */
 471 asmlinkage int sys_setpgid(pid_t pid, pid_t pgid)
     /*  */
 472 {
 473         struct task_struct * p;
 474 
 475         if (!pid)
 476                 pid = current->pid;
 477         if (!pgid)
 478                 pgid = pid;
 479         if (pgid < 0)
 480                 return -EINVAL;
 481         for_each_task(p) {
 482                 if (p->pid == pid)
 483                         goto found_task;
 484         }
 485         return -ESRCH;
 486 
 487 found_task:
 488         if (p->p_pptr == current || p->p_opptr == current) {
 489                 if (p->session != current->session)
 490                         return -EPERM;
 491                 if (p->did_exec)
 492                         return -EACCES;
 493         } else if (p != current)
 494                 return -ESRCH;
 495         if (p->leader)
 496                 return -EPERM;
 497         if (pgid != pid) {
 498                 struct task_struct * tmp;
 499                 for_each_task (tmp) {
 500                         if (tmp->pgrp == pgid &&
 501                          tmp->session == current->session)
 502                                 goto ok_pgid;
 503                 }
 504                 return -EPERM;
 505         }
 506 
 507 ok_pgid:
 508         p->pgrp = pgid;
 509         return 0;
 510 }
 511 
 512 asmlinkage int sys_getpgid(pid_t pid)
     /*  */
 513 {
 514         struct task_struct * p;
 515 
 516         if (!pid)
 517                 return current->pgrp;
 518         for_each_task(p) {
 519                 if (p->pid == pid)
 520                         return p->pgrp;
 521         }
 522         return -ESRCH;
 523 }
 524 
 525 asmlinkage int sys_getpgrp(void)
     /*  */
 526 {
 527         return current->pgrp;
 528 }
 529 
 530 asmlinkage int sys_setsid(void)
     /*  */
 531 {
 532         if (current->leader)
 533                 return -EPERM;
 534         current->leader = 1;
 535         current->session = current->pgrp = current->pid;
 536         current->tty = NULL;
 537         current->tty_old_pgrp = 0;
 538         return current->pgrp;
 539 }
 540 
 541 /*
 542  * Supplementary group ID's
 543  */
 544 asmlinkage int sys_getgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 545 {
 546         int i;
 547         int * groups;
 548 
 549         if (gidsetsize) {
 550                 i = verify_area(VERIFY_WRITE, grouplist, sizeof(gid_t) * gidsetsize);
 551                 if (i)
 552                         return i;
 553         }
 554         groups = current->groups;
 555         for (i = 0 ; (i < NGROUPS) && (*groups != NOGROUP) ; i++, groups++) {
 556                 if (!gidsetsize)
 557                         continue;
 558                 if (i >= gidsetsize)
 559                         break;
 560                 put_user(*groups, grouplist);
 561                 grouplist++;
 562         }
 563         return(i);
 564 }
 565 
 566 asmlinkage int sys_setgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 567 {
 568         int     i;
 569 
 570         if (!suser())
 571                 return -EPERM;
 572         if (gidsetsize > NGROUPS)
 573                 return -EINVAL;
 574         i = verify_area(VERIFY_READ, grouplist, sizeof(gid_t) * gidsetsize);
 575         if (i)
 576                 return i;
 577         for (i = 0; i < gidsetsize; i++, grouplist++) {
 578                 current->groups[i] = get_user(grouplist);
 579         }
 580         if (i < NGROUPS)
 581                 current->groups[i] = NOGROUP;
 582         return 0;
 583 }
 584 
 585 int in_group_p(gid_t grp)
     /*  */
 586 {
 587         int     i;
 588 
 589         if (grp == current->fsgid)
 590                 return 1;
 591 
 592         for (i = 0; i < NGROUPS; i++) {
 593                 if (current->groups[i] == NOGROUP)
 594                         break;
 595                 if (current->groups[i] == grp)
 596                         return 1;
 597         }
 598         return 0;
 599 }
 600 
 601 asmlinkage int sys_newuname(struct new_utsname * name)
     /*  */
 602 {
 603         int error;
 604 
 605         if (!name)
 606                 return -EFAULT;
 607         error = verify_area(VERIFY_WRITE, name, sizeof *name);
 608         if (!error)
 609                 memcpy_tofs(name,&system_utsname,sizeof *name);
 610         return error;
 611 }
 612 
 613 asmlinkage int sys_uname(struct old_utsname * name)
     /*  */
 614 {
 615         int error;
 616         if (!name)
 617                 return -EFAULT;
 618         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 619         if (error)
 620                 return error;
 621         memcpy_tofs(&name->sysname,&system_utsname.sysname,
 622                 sizeof (system_utsname.sysname));
 623         memcpy_tofs(&name->nodename,&system_utsname.nodename,
 624                 sizeof (system_utsname.nodename));
 625         memcpy_tofs(&name->release,&system_utsname.release,
 626                 sizeof (system_utsname.release));
 627         memcpy_tofs(&name->version,&system_utsname.version,
 628                 sizeof (system_utsname.version));
 629         memcpy_tofs(&name->machine,&system_utsname.machine,
 630                 sizeof (system_utsname.machine));
 631         return 0;
 632 }
 633 
 634 asmlinkage int sys_olduname(struct oldold_utsname * name)
     /*  */
 635 {
 636         int error;
 637         if (!name)
 638                 return -EFAULT;
 639         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 640         if (error)
 641                 return error;
 642         memcpy_tofs(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 643         put_user(0,name->sysname+__OLD_UTS_LEN);
 644         memcpy_tofs(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 645         put_user(0,name->nodename+__OLD_UTS_LEN);
 646         memcpy_tofs(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 647         put_user(0,name->release+__OLD_UTS_LEN);
 648         memcpy_tofs(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 649         put_user(0,name->version+__OLD_UTS_LEN);
 650         memcpy_tofs(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 651         put_user(0,name->machine+__OLD_UTS_LEN);
 652         return 0;
 653 }
 654 
 655 asmlinkage int sys_sethostname(char *name, int len)
     /*  */
 656 {
 657         int error;
 658 
 659         if (!suser())
 660                 return -EPERM;
 661         if (len < 0 || len > __NEW_UTS_LEN)
 662                 return -EINVAL;
 663         error = verify_area(VERIFY_READ, name, len);
 664         if (error)
 665                 return error;
 666         memcpy_fromfs(system_utsname.nodename, name, len);
 667         system_utsname.nodename[len] = 0;
 668         return 0;
 669 }
 670 
 671 asmlinkage int sys_gethostname(char *name, int len)
     /*  */
 672 {
 673         int i;
 674 
 675         if (len < 0)
 676                 return -EINVAL;
 677         i = verify_area(VERIFY_WRITE, name, len);
 678         if (i)
 679                 return i;
 680         i = 1+strlen(system_utsname.nodename);
 681         if (i > len)
 682                 i = len;
 683         memcpy_tofs(name, system_utsname.nodename, i);
 684         return 0;
 685 }
 686 
 687 /*
 688  * Only setdomainname; getdomainname can be implemented by calling
 689  * uname()
 690  */
 691 asmlinkage int sys_setdomainname(char *name, int len)
     /*  */
 692 {
 693         int error;
 694         
 695         if (!suser())
 696                 return -EPERM;
 697         if (len > __NEW_UTS_LEN)
 698                 return -EINVAL;
 699         error = verify_area(VERIFY_READ, name, len);
 700         if (error)
 701                 return error;
 702         memcpy_fromfs(system_utsname.domainname, name, len);
 703         system_utsname.domainname[len] = 0;
 704         return 0;
 705 }
 706 
 707 asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 708 {
 709         int error;
 710 
 711         if (resource >= RLIM_NLIMITS)
 712                 return -EINVAL;
 713         error = verify_area(VERIFY_WRITE,rlim,sizeof *rlim);
 714         if (error)
 715                 return error;
 716         memcpy_tofs(rlim, current->rlim + resource, sizeof(*rlim));
 717         return 0;       
 718 }
 719 
 720 asmlinkage int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 721 {
 722         struct rlimit new_rlim, *old_rlim;
 723         int err;
 724 
 725         if (resource >= RLIM_NLIMITS)
 726                 return -EINVAL;
 727         err = verify_area(VERIFY_READ, rlim, sizeof(*rlim));
 728         if (err)
 729                 return err;
 730         memcpy_fromfs(&new_rlim, rlim, sizeof(*rlim));
 731         old_rlim = current->rlim + resource;
 732         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
 733              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
 734             !suser())
 735                 return -EPERM;
 736         if (resource == RLIMIT_NOFILE) {
 737                 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
 738                         return -EPERM;
 739         }
 740         *old_rlim = new_rlim;
 741         return 0;
 742 }
 743 
 744 /*
 745  * It would make sense to put struct rusage in the task_struct,
 746  * except that would make the task_struct be *really big*.  After
 747  * task_struct gets moved into malloc'ed memory, it would
 748  * make sense to do this.  It will make moving the rest of the information
 749  * a lot simpler!  (Which we're not doing right now because we're not
 750  * measuring them yet).
 751  */
 752 int getrusage(struct task_struct *p, int who, struct rusage *ru)
     /*  */
 753 {
 754         int error;
 755         struct rusage r;
 756 
 757         error = verify_area(VERIFY_WRITE, ru, sizeof *ru);
 758         if (error)
 759                 return error;
 760         memset((char *) &r, 0, sizeof(r));
 761         switch (who) {
 762                 case RUSAGE_SELF:
 763                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime);
 764                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime);
 765                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime);
 766                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime);
 767                         r.ru_minflt = p->mm->min_flt;
 768                         r.ru_majflt = p->mm->maj_flt;
 769                         break;
 770                 case RUSAGE_CHILDREN:
 771                         r.ru_utime.tv_sec = CT_TO_SECS(p->cutime);
 772                         r.ru_utime.tv_usec = CT_TO_USECS(p->cutime);
 773                         r.ru_stime.tv_sec = CT_TO_SECS(p->cstime);
 774                         r.ru_stime.tv_usec = CT_TO_USECS(p->cstime);
 775                         r.ru_minflt = p->mm->cmin_flt;
 776                         r.ru_majflt = p->mm->cmaj_flt;
 777                         break;
 778                 default:
 779                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime + p->cutime);
 780                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime + p->cutime);
 781                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime + p->cstime);
 782                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime + p->cstime);
 783                         r.ru_minflt = p->mm->min_flt + p->mm->cmin_flt;
 784                         r.ru_majflt = p->mm->maj_flt + p->mm->cmaj_flt;
 785                         break;
 786         }
 787         memcpy_tofs(ru, &r, sizeof(r));
 788         return 0;
 789 }
 790 
 791 asmlinkage int sys_getrusage(int who, struct rusage *ru)
     /*  */
 792 {
 793         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
 794                 return -EINVAL;
 795         return getrusage(current, who, ru);
 796 }
 797 
 798 asmlinkage int sys_umask(int mask)
     /*  */
 799 {
 800         int old = current->fs->umask;
 801 
 802         current->fs->umask = mask & S_IRWXUGO;
 803         return (old);
 804 }

/* */