root/kernel/sys.c

/* */

DEFINITIONS

1. sys_ni_syscall
2. sys_idle
3. proc_sel
4. sys_setpriority
5. sys_getpriority
6. sys_profil
7. sys_ftime
8. sys_break
9. sys_stty
10. sys_gtty
11. sys_prof
12. sys_reboot
13. ctrl_alt_del
14. sys_setregid
15. sys_setgid
16. sys_acct
17. sys_phys
18. sys_lock
19. sys_mpx
20. sys_ulimit
21. sys_old_syscall
22. sys_setreuid
23. sys_setuid
24. sys_setfsuid
25. sys_setfsgid
26. sys_times
27. sys_brk
28. sys_setpgid
29. sys_getpgid
30. sys_getpgrp
31. sys_setsid
32. sys_getgroups
33. sys_setgroups
34. in_group_p
35. sys_newuname
36. sys_uname
37. sys_olduname
38. sys_sethostname
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/config.h>
   8 #include <linux/errno.h>
   9 #include <linux/sched.h>
  10 #include <linux/kernel.h>
  11 #include <linux/times.h>
  12 #include <linux/utsname.h>
  13 #include <linux/param.h>
  14 #include <linux/resource.h>
  15 #include <linux/signal.h>
  16 #include <linux/string.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/stat.h>
  19 #include <linux/mman.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 asmlinkage int sys_idle(void)
     /*  */
  39 {
  40         int i;
  41 
  42         if (current->pid != 0)
  43                 return -EPERM;
  44 
  45         /* Map out the low memory: it's no longer needed */
  46         for (i = 0 ; i < 768 ; i++)
  47                 swapper_pg_dir[i] = 0;
  48 
  49         /* endless idle loop with no priority at all */
  50         current->counter = -100;
  51         for (;;) {
  52                 if (hlt_works_ok && !need_resched)
  53                         __asm__("hlt");
  54                 schedule();
  55         }
  56 }
  57 
  58 static int proc_sel(struct task_struct *p, int which, int who)
     /*  */
  59 {
  60         switch (which) {
  61                 case PRIO_PROCESS:
  62                         if (!who && p == current)
  63                                 return 1;
  64                         return(p->pid == who);
  65                 case PRIO_PGRP:
  66                         if (!who)
  67                                 who = current->pgrp;
  68                         return(p->pgrp == who);
  69                 case PRIO_USER:
  70                         if (!who)
  71                                 who = current->uid;
  72                         return(p->uid == who);
  73         }
  74         return 0;
  75 }
  76 
  77 asmlinkage int sys_setpriority(int which, int who, int niceval)
     /*  */
  78 {
  79         struct task_struct **p;
  80         int error = ESRCH;
  81         int priority;
  82 
  83         if (which > 2 || which < 0)
  84                 return -EINVAL;
  85 
  86         if ((priority = PZERO - niceval) <= 0)
  87                 priority = 1;
  88 
  89         for(p = &LAST_TASK; p > &FIRST_TASK; --p) {
  90                 if (!*p || !proc_sel(*p, which, who))
  91                         continue;
  92                 if ((*p)->uid != current->euid &&
  93                         (*p)->uid != current->uid && !suser()) {
  94                         error = EPERM;
  95                         continue;
  96                 }
  97                 if (error == ESRCH)
  98                         error = 0;
  99                 if (priority > (*p)->priority && !suser())
 100                         error = EACCES;
 101                 else
 102                         (*p)->priority = priority;
 103         }
 104         return -error;
 105 }
 106 
 107 asmlinkage int sys_getpriority(int which, int who)
     /*  */
 108 {
 109         struct task_struct **p;
 110         int max_prio = 0;
 111 
 112         if (which > 2 || which < 0)
 113                 return -EINVAL;
 114 
 115         for(p = &LAST_TASK; p > &FIRST_TASK; --p) {
 116                 if (!*p || !proc_sel(*p, which, who))
 117                         continue;
 118                 if ((*p)->priority > max_prio)
 119                         max_prio = (*p)->priority;
 120         }
 121         return(max_prio ? max_prio : -ESRCH);
 122 }
 123 
 124 asmlinkage int sys_profil(void)
     /*  */
 125 {
 126         return -ENOSYS;
 127 }
 128 
 129 asmlinkage int sys_ftime(void)
     /*  */
 130 {
 131         return -ENOSYS;
 132 }
 133 
 134 asmlinkage int sys_break(void)
     /*  */
 135 {
 136         return -ENOSYS;
 137 }
 138 
 139 asmlinkage int sys_stty(void)
     /*  */
 140 {
 141         return -ENOSYS;
 142 }
 143 
 144 asmlinkage int sys_gtty(void)
     /*  */
 145 {
 146         return -ENOSYS;
 147 }
 148 
 149 asmlinkage int sys_prof(void)
     /*  */
 150 {
 151         return -ENOSYS;
 152 }
 153 
 154 extern void hard_reset_now(void);
 155 
 156 /*
 157  * Reboot system call: for obvious reasons only root may call it,
 158  * and even root needs to set up some magic numbers in the registers
 159  * so that some mistake won't make this reboot the whole machine.
 160  * You can also set the meaning of the ctrl-alt-del-key here.
 161  *
 162  * reboot doesn't sync: do that yourself before calling this.
 163  */
 164 asmlinkage int sys_reboot(int magic, int magic_too, int flag)
     /*  */
 165 {
 166         if (!suser())
 167                 return -EPERM;
 168         if (magic != 0xfee1dead || magic_too != 672274793)
 169                 return -EINVAL;
 170         if (flag == 0x01234567)
 171                 hard_reset_now();
 172         else if (flag == 0x89ABCDEF)
 173                 C_A_D = 1;
 174         else if (!flag)
 175                 C_A_D = 0;
 176         else
 177                 return -EINVAL;
 178         return (0);
 179 }
 180 
 181 /*
 182  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 183  * As it's called within an interrupt, it may NOT sync: the only choice
 184  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 185  */
 186 void ctrl_alt_del(void)
     /*  */
 187 {
 188         if (C_A_D)
 189                 hard_reset_now();
 190         else
 191                 send_sig(SIGINT,task[1],1);
 192 }
 193         
 194 
 195 /*
 196  * Unprivileged users may change the real gid to the effective gid
 197  * or vice versa.  (BSD-style)
 198  *
 199  * If you set the real gid at all, or set the effective gid to a value not
 200  * equal to the real gid, then the saved gid is set to the new effective gid.
 201  *
 202  * This makes it possible for a setgid program to completely drop its
 203  * privileges, which is often a useful assertion to make when you are doing
 204  * a security audit over a program.
 205  *
 206  * The general idea is that a program which uses just setregid() will be
 207  * 100% compatible with BSD.  A program which uses just setgid() will be
 208  * 100% compatible with POSIX w/ Saved ID's. 
 209  */
 210 asmlinkage int sys_setregid(gid_t rgid, gid_t egid)
     /*  */
 211 {
 212         int old_rgid = current->gid;
 213 
 214         if (rgid != (gid_t) -1) {
 215                 if ((old_rgid == rgid) ||
 216                     (current->egid==rgid) ||
 217                     suser())
 218                         current->gid = rgid;
 219                 else
 220                         return(-EPERM);
 221         }
 222         if (egid != (gid_t) -1) {
 223                 if ((old_rgid == egid) ||
 224                     (current->egid == egid) ||
 225                     (current->sgid == egid) ||
 226                     suser())
 227                         current->egid = egid;
 228                 else {
 229                         current->gid = old_rgid;
 230                         return(-EPERM);
 231                 }
 232         }
 233         if (rgid != (gid_t) -1 ||
 234             (egid != (gid_t) -1 && egid != old_rgid))
 235                 current->sgid = current->egid;
 236         current->fsgid = current->egid;
 237         return 0;
 238 }
 239 
 240 /*
 241  * setgid() is implemented like SysV w/ SAVED_IDS 
 242  */
 243 asmlinkage int sys_setgid(gid_t gid)
     /*  */
 244 {
 245         if (suser())
 246                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 247         else if ((gid == current->gid) || (gid == current->sgid))
 248                 current->egid = current->fsgid = gid;
 249         else
 250                 return -EPERM;
 251         return 0;
 252 }
 253 
 254 asmlinkage int sys_acct(void)
     /*  */
 255 {
 256         return -ENOSYS;
 257 }
 258 
 259 asmlinkage int sys_phys(void)
     /*  */
 260 {
 261         return -ENOSYS;
 262 }
 263 
 264 asmlinkage int sys_lock(void)
     /*  */
 265 {
 266         return -ENOSYS;
 267 }
 268 
 269 asmlinkage int sys_mpx(void)
     /*  */
 270 {
 271         return -ENOSYS;
 272 }
 273 
 274 asmlinkage int sys_ulimit(void)
     /*  */
 275 {
 276         return -ENOSYS;
 277 }
 278 
 279 asmlinkage int sys_old_syscall(void)
     /*  */
 280 {
 281         return -ENOSYS;
 282 }
 283 
 284 /*
 285  * Unprivileged users may change the real uid to the effective uid
 286  * or vice versa.  (BSD-style)
 287  *
 288  * If you set the real uid at all, or set the effective uid to a value not
 289  * equal to the real uid, then the saved uid is set to the new effective uid.
 290  *
 291  * This makes it possible for a setuid program to completely drop its
 292  * privileges, which is often a useful assertion to make when you are doing
 293  * a security audit over a program.
 294  *
 295  * The general idea is that a program which uses just setreuid() will be
 296  * 100% compatible with BSD.  A program which uses just setuid() will be
 297  * 100% compatible with POSIX w/ Saved ID's. 
 298  */
 299 asmlinkage int sys_setreuid(uid_t ruid, uid_t euid)
     /*  */
 300 {
 301         int old_ruid = current->uid;
 302 
 303         if (ruid != (uid_t) -1) {
 304                 if ((old_ruid == ruid) || 
 305                     (current->euid==ruid) ||
 306                     suser())
 307                         current->uid = ruid;
 308                 else
 309                         return(-EPERM);
 310         }
 311         if (euid != (uid_t) -1) {
 312                 if ((old_ruid == euid) ||
 313                     (current->euid == euid) ||
 314                     (current->suid == euid) ||
 315                     suser())
 316                         current->euid = euid;
 317                 else {
 318                         current->uid = old_ruid;
 319                         return(-EPERM);
 320                 }
 321         }
 322         if (ruid != (uid_t) -1 ||
 323             (euid != (uid_t) -1 && euid != old_ruid))
 324                 current->suid = current->euid;
 325         current->fsuid = current->euid;
 326         return 0;
 327 }
 328 
 329 /*
 330  * setuid() is implemented like SysV w/ SAVED_IDS 
 331  * 
 332  * Note that SAVED_ID's is deficient in that a setuid root program
 333  * like sendmail, for example, cannot set its uid to be a normal 
 334  * user and then switch back, because if you're root, setuid() sets
 335  * the saved uid too.  If you don't like this, blame the bright people
 336  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 337  * will allow a root program to temporarily drop privileges and be able to
 338  * regain them by swapping the real and effective uid.  
 339  */
 340 asmlinkage int sys_setuid(uid_t uid)
     /*  */
 341 {
 342         if (suser())
 343                 current->uid = current->euid = current->suid = current->fsuid = uid;
 344         else if ((uid == current->uid) || (uid == current->suid))
 345                 current->fsuid = current->euid = uid;
 346         else
 347                 return -EPERM;
 348         return(0);
 349 }
 350 
 351 /*
 352  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 353  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 354  * whatever uid it wants to). It normally shadows "euid", except when
 355  * explicitly set by setfsuid() or for access..
 356  */
 357 asmlinkage int sys_setfsuid(uid_t uid)
     /*  */
 358 {
 359         int old_fsuid = current->fsuid;
 360 
 361         if (uid == current->uid || uid == current->euid ||
 362             uid == current->suid || uid == current->fsuid || suser())
 363                 current->fsuid = uid;
 364         return old_fsuid;
 365 }
 366 
 367 /*
 368  * Samma på svenska..
 369  */
 370 asmlinkage int sys_setfsgid(gid_t gid)
     /*  */
 371 {
 372         int old_fsgid = current->fsgid;
 373 
 374         if (gid == current->gid || gid == current->egid ||
 375             gid == current->sgid || gid == current->fsgid || suser())
 376                 current->fsgid = gid;
 377         return old_fsgid;
 378 }
 379 
 380 asmlinkage int sys_times(struct tms * tbuf)
     /*  */
 381 {
 382         if (tbuf) {
 383                 int error = verify_area(VERIFY_WRITE,tbuf,sizeof *tbuf);
 384                 if (error)
 385                         return error;
 386                 put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime);
 387                 put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime);
 388                 put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime);
 389                 put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime);
 390         }
 391         return jiffies;
 392 }
 393 
 394 asmlinkage int sys_brk(unsigned long brk)
     /*  */
 395 {
 396         int freepages;
 397         unsigned long rlim;
 398         unsigned long newbrk, oldbrk;
 399         struct vm_area_struct * vma;
 400 
 401         if (brk < current->mm->end_code)
 402                 return current->mm->brk;
 403         newbrk = PAGE_ALIGN(brk);
 404         oldbrk = PAGE_ALIGN(current->mm->brk);
 405         if (oldbrk == newbrk)
 406                 return current->mm->brk = brk;
 407 
 408         /*
 409          * Always allow shrinking brk
 410          */
 411         if (brk <= current->mm->brk) {
 412                 current->mm->brk = brk;
 413                 do_munmap(newbrk, oldbrk-newbrk);
 414                 return brk;
 415         }
 416         /*
 417          * Check against rlimit and stack..
 418          */
 419         rlim = current->rlim[RLIMIT_DATA].rlim_cur;
 420         if (rlim >= RLIM_INFINITY)
 421                 rlim = ~0;
 422         if (brk - current->mm->end_code > rlim ||
 423             brk >= current->mm->start_stack - 16384)
 424                 return current->mm->brk;
 425         /*
 426          * Check against existing mmap mappings.
 427          */
 428         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
 429                 if (newbrk <= vma->vm_start)
 430                         break;
 431                 if (oldbrk < vma->vm_end)
 432                         return current->mm->brk;
 433         }
 434         /*
 435          * stupid algorithm to decide if we have enough memory: while
 436          * simple, it hopefully works in most obvious cases.. Easy to
 437          * fool it, but this should catch most mistakes.
 438          */
 439         freepages = buffermem >> 12;
 440         freepages += nr_free_pages;
 441         freepages += nr_swap_pages;
 442         freepages -= (high_memory - 0x100000) >> 16;
 443         freepages -= (newbrk-oldbrk) >> 12;
 444         if (freepages < 0)
 445                 return current->mm->brk;
 446 #if 0
 447         freepages += current->mm->rss;
 448         freepages -= oldbrk >> 12;
 449         if (freepages < 0)
 450                 return current->mm->brk;
 451 #endif
 452         /*
 453          * Ok, we have probably got enough memory - let it rip.
 454          */
 455         current->mm->brk = brk;
 456         do_mmap(NULL, oldbrk, newbrk-oldbrk,
 457                 PROT_READ|PROT_WRITE|PROT_EXEC,
 458                 MAP_FIXED|MAP_PRIVATE, 0);
 459         return brk;
 460 }
 461 
 462 /*
 463  * This needs some heave checking ...
 464  * I just haven't get the stomach for it. I also don't fully
 465  * understand sessions/pgrp etc. Let somebody who does explain it.
 466  *
 467  * OK, I think I have the protection semantics right.... this is really
 468  * only important on a multi-user system anyway, to make sure one user
 469  * can't send a signal to a process owned by another.  -TYT, 12/12/91
 470  *
 471  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 472  * LBT 04.03.94
 473  */
 474 asmlinkage int sys_setpgid(pid_t pid, pid_t pgid)
     /*  */
 475 {
 476         struct task_struct * p;
 477 
 478         if (!pid)
 479                 pid = current->pid;
 480         if (!pgid)
 481                 pgid = pid;
 482         if (pgid < 0)
 483                 return -EINVAL;
 484         for_each_task(p) {
 485                 if (p->pid == pid)
 486                         goto found_task;
 487         }
 488         return -ESRCH;
 489 
 490 found_task:
 491         if (p->p_pptr == current || p->p_opptr == current) {
 492                 if (p->session != current->session)
 493                         return -EPERM;
 494                 if (p->did_exec)
 495                         return -EACCES;
 496         } else if (p != current)
 497                 return -ESRCH;
 498         if (p->leader)
 499                 return -EPERM;
 500         if (pgid != pid) {
 501                 struct task_struct * tmp;
 502                 for_each_task (tmp) {
 503                         if (tmp->pgrp == pgid &&
 504                          tmp->session == current->session)
 505                                 goto ok_pgid;
 506                 }
 507                 return -EPERM;
 508         }
 509 
 510 ok_pgid:
 511         p->pgrp = pgid;
 512         return 0;
 513 }
 514 
 515 asmlinkage int sys_getpgid(pid_t pid)
     /*  */
 516 {
 517         struct task_struct * p;
 518 
 519         if (!pid)
 520                 return current->pgrp;
 521         for_each_task(p) {
 522                 if (p->pid == pid)
 523                         return p->pgrp;
 524         }
 525         return -ESRCH;
 526 }
 527 
 528 asmlinkage int sys_getpgrp(void)
     /*  */
 529 {
 530         return current->pgrp;
 531 }
 532 
 533 asmlinkage int sys_setsid(void)
     /*  */
 534 {
 535         if (current->leader)
 536                 return -EPERM;
 537         current->leader = 1;
 538         current->session = current->pgrp = current->pid;
 539         current->tty = NULL;
 540         return current->pgrp;
 541 }
 542 
 543 /*
 544  * Supplementary group ID's
 545  */
 546 asmlinkage int sys_getgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 547 {
 548         int i;
 549 
 550         if (gidsetsize) {
 551                 i = verify_area(VERIFY_WRITE, grouplist, sizeof(gid_t) * gidsetsize);
 552                 if (i)
 553                         return i;
 554         }
 555         for (i = 0 ; (i < NGROUPS) && (current->groups[i] != NOGROUP) ; i++) {
 556                 if (!gidsetsize)
 557                         continue;
 558                 if (i >= gidsetsize)
 559                         break;
 560                 put_fs_word(current->groups[i], (short *) 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         for (i = 0; i < gidsetsize; i++, grouplist++) {
 575                 current->groups[i] = get_fs_word((unsigned short *) grouplist);
 576         }
 577         if (i < NGROUPS)
 578                 current->groups[i] = NOGROUP;
 579         return 0;
 580 }
 581 
 582 int in_group_p(gid_t grp)
     /*  */
 583 {
 584         int     i;
 585 
 586         if (grp == current->fsgid)
 587                 return 1;
 588 
 589         for (i = 0; i < NGROUPS; i++) {
 590                 if (current->groups[i] == NOGROUP)
 591                         break;
 592                 if (current->groups[i] == grp)
 593                         return 1;
 594         }
 595         return 0;
 596 }
 597 
 598 asmlinkage int sys_newuname(struct new_utsname * name)
     /*  */
 599 {
 600         int error;
 601 
 602         if (!name)
 603                 return -EFAULT;
 604         error = verify_area(VERIFY_WRITE, name, sizeof *name);
 605         if (!error)
 606                 memcpy_tofs(name,&system_utsname,sizeof *name);
 607         return error;
 608 }
 609 
 610 asmlinkage int sys_uname(struct old_utsname * name)
     /*  */
 611 {
 612         int error;
 613         if (!name)
 614                 return -EFAULT;
 615         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 616         if (error)
 617                 return error;
 618         memcpy_tofs(&name->sysname,&system_utsname.sysname,
 619                 sizeof (system_utsname.sysname));
 620         memcpy_tofs(&name->nodename,&system_utsname.nodename,
 621                 sizeof (system_utsname.nodename));
 622         memcpy_tofs(&name->release,&system_utsname.release,
 623                 sizeof (system_utsname.release));
 624         memcpy_tofs(&name->version,&system_utsname.version,
 625                 sizeof (system_utsname.version));
 626         memcpy_tofs(&name->machine,&system_utsname.machine,
 627                 sizeof (system_utsname.machine));
 628         return 0;
 629 }
 630 
 631 asmlinkage int sys_olduname(struct oldold_utsname * name)
     /*  */
 632 {
 633         int error;
 634         if (!name)
 635                 return -EFAULT;
 636         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 637         if (error)
 638                 return error;
 639         memcpy_tofs(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 640         put_fs_byte(0,name->sysname+__OLD_UTS_LEN);
 641         memcpy_tofs(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 642         put_fs_byte(0,name->nodename+__OLD_UTS_LEN);
 643         memcpy_tofs(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 644         put_fs_byte(0,name->release+__OLD_UTS_LEN);
 645         memcpy_tofs(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 646         put_fs_byte(0,name->version+__OLD_UTS_LEN);
 647         memcpy_tofs(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 648         put_fs_byte(0,name->machine+__OLD_UTS_LEN);
 649         return 0;
 650 }
 651 
 652 /*
 653  * Only sethostname; gethostname can be implemented by calling uname()
 654  */
 655 asmlinkage int sys_sethostname(char *name, int len)
     /*  */
 656 {
 657         int     i;
 658         
 659         if (!suser())
 660                 return -EPERM;
 661         if (len > __NEW_UTS_LEN)
 662                 return -EINVAL;
 663         for (i=0; i < len; i++) {
 664                 if ((system_utsname.nodename[i] = get_fs_byte(name+i)) == 0)
 665                         return 0;
 666         }
 667         system_utsname.nodename[i] = 0;
 668         return 0;
 669 }
 670 
 671 /*
 672  * Only setdomainname; getdomainname can be implemented by calling
 673  * uname()
 674  */
 675 asmlinkage int sys_setdomainname(char *name, int len)
     /*  */
 676 {
 677         int     i;
 678         
 679         if (!suser())
 680                 return -EPERM;
 681         if (len > __NEW_UTS_LEN)
 682                 return -EINVAL;
 683         for (i=0; i < len; i++) {
 684                 if ((system_utsname.domainname[i] = get_fs_byte(name+i)) == 0)
 685                         return 0;
 686         }
 687         system_utsname.domainname[i] = 0;
 688         return 0;
 689 }
 690 
 691 asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 692 {
 693         int error;
 694 
 695         if (resource >= RLIM_NLIMITS)
 696                 return -EINVAL;
 697         error = verify_area(VERIFY_WRITE,rlim,sizeof *rlim);
 698         if (error)
 699                 return error;
 700         put_fs_long(current->rlim[resource].rlim_cur, 
 701                     (unsigned long *) rlim);
 702         put_fs_long(current->rlim[resource].rlim_max, 
 703                     ((unsigned long *) rlim)+1);
 704         return 0;       
 705 }
 706 
 707 asmlinkage int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 708 {
 709         struct rlimit new_rlim, *old_rlim;
 710         int err;
 711 
 712         if (resource >= RLIM_NLIMITS)
 713                 return -EINVAL;
 714         err = verify_area(VERIFY_READ, rlim, sizeof(*rlim));
 715         if (err)
 716                 return err;
 717         memcpy_fromfs(&new_rlim, rlim, sizeof(*rlim));
 718         old_rlim = current->rlim + resource;
 719         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
 720              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
 721             !suser())
 722                 return -EPERM;
 723         *old_rlim = new_rlim;
 724         return 0;
 725 }
 726 
 727 /*
 728  * It would make sense to put struct rusage in the task_struct,
 729  * except that would make the task_struct be *really big*.  After
 730  * task_struct gets moved into malloc'ed memory, it would
 731  * make sense to do this.  It will make moving the rest of the information
 732  * a lot simpler!  (Which we're not doing right now because we're not
 733  * measuring them yet).
 734  */
 735 int getrusage(struct task_struct *p, int who, struct rusage *ru)
     /*  */
 736 {
 737         int error;
 738         struct rusage r;
 739 
 740         error = verify_area(VERIFY_WRITE, ru, sizeof *ru);
 741         if (error)
 742                 return error;
 743         memset((char *) &r, 0, sizeof(r));
 744         switch (who) {
 745                 case RUSAGE_SELF:
 746                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime);
 747                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime);
 748                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime);
 749                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime);
 750                         r.ru_minflt = p->mm->min_flt;
 751                         r.ru_majflt = p->mm->maj_flt;
 752                         break;
 753                 case RUSAGE_CHILDREN:
 754                         r.ru_utime.tv_sec = CT_TO_SECS(p->cutime);
 755                         r.ru_utime.tv_usec = CT_TO_USECS(p->cutime);
 756                         r.ru_stime.tv_sec = CT_TO_SECS(p->cstime);
 757                         r.ru_stime.tv_usec = CT_TO_USECS(p->cstime);
 758                         r.ru_minflt = p->mm->cmin_flt;
 759                         r.ru_majflt = p->mm->cmaj_flt;
 760                         break;
 761                 default:
 762                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime + p->cutime);
 763                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime + p->cutime);
 764                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime + p->cstime);
 765                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime + p->cstime);
 766                         r.ru_minflt = p->mm->min_flt + p->mm->cmin_flt;
 767                         r.ru_majflt = p->mm->maj_flt + p->mm->cmaj_flt;
 768                         break;
 769         }
 770         memcpy_tofs(ru, &r, sizeof(r));
 771         return 0;
 772 }
 773 
 774 asmlinkage int sys_getrusage(int who, struct rusage *ru)
     /*  */
 775 {
 776         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
 777                 return -EINVAL;
 778         return getrusage(current, who, ru);
 779 }
 780 
 781 asmlinkage int sys_umask(int mask)
     /*  */
 782 {
 783         int old = current->fs->umask;
 784 
 785         current->fs->umask = mask & S_IRWXUGO;
 786         return (old);
 787 }

/* */