kernel/sys.c

/* */
This source file includes following definitions.
sys_ni_syscall
sys_idle
proc_sel
sys_setpriority
sys_getpriority
sys_profil
sys_ftime
sys_break
sys_stty
sys_gtty
sys_prof
sys_reboot
ctrl_alt_del
sys_setregid
sys_setgid
sys_acct
sys_phys
sys_lock
sys_mpx
sys_ulimit
sys_old_syscall
sys_setreuid
sys_setuid
sys_times
sys_brk
sys_setpgid
sys_getpgid
sys_getpgrp
sys_setsid
sys_getgroups
sys_setgroups
in_group_p
sys_newuname
sys_uname
sys_olduname
sys_sethostname
sys_setdomainname
sys_getrlimit
sys_setrlimit
getrusage
sys_getrusage
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 -EINVAL;
  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         return 0;
 237 }
 238 
 239 /*
 240  * setgid() is implemented like SysV w/ SAVED_IDS 
 241  */
 242 asmlinkage int sys_setgid(gid_t gid)
     /*  */
 243 {
 244         if (suser())
 245                 current->gid = current->egid = current->sgid = gid;
 246         else if ((gid == current->gid) || (gid == current->sgid))
 247                 current->egid = gid;
 248         else
 249                 return -EPERM;
 250         return 0;
 251 }
 252 
 253 asmlinkage int sys_acct(void)
     /*  */
 254 {
 255         return -ENOSYS;
 256 }
 257 
 258 asmlinkage int sys_phys(void)
     /*  */
 259 {
 260         return -ENOSYS;
 261 }
 262 
 263 asmlinkage int sys_lock(void)
     /*  */
 264 {
 265         return -ENOSYS;
 266 }
 267 
 268 asmlinkage int sys_mpx(void)
     /*  */
 269 {
 270         return -ENOSYS;
 271 }
 272 
 273 asmlinkage int sys_ulimit(void)
     /*  */
 274 {
 275         return -ENOSYS;
 276 }
 277 
 278 asmlinkage int sys_old_syscall(void)
     /*  */
 279 {
 280         return -ENOSYS;
 281 }
 282 
 283 /*
 284  * Unprivileged users may change the real uid to the effective uid
 285  * or vice versa.  (BSD-style)
 286  *
 287  * If you set the real uid at all, or set the effective uid to a value not
 288  * equal to the real uid, then the saved uid is set to the new effective uid.
 289  *
 290  * This makes it possible for a setuid program to completely drop its
 291  * privileges, which is often a useful assertion to make when you are doing
 292  * a security audit over a program.
 293  *
 294  * The general idea is that a program which uses just setreuid() will be
 295  * 100% compatible with BSD.  A program which uses just setuid() will be
 296  * 100% compatible with POSIX w/ Saved ID's. 
 297  */
 298 asmlinkage int sys_setreuid(uid_t ruid, uid_t euid)
     /*  */
 299 {
 300         int old_ruid = current->uid;
 301 
 302         if (ruid != (uid_t) -1) {
 303                 if ((old_ruid == ruid) || 
 304                     (current->euid==ruid) ||
 305                     suser())
 306                         current->uid = ruid;
 307                 else
 308                         return(-EPERM);
 309         }
 310         if (euid != (uid_t) -1) {
 311                 if ((old_ruid == euid) ||
 312                     (current->euid == euid) ||
 313                     (current->suid == euid) ||
 314                     suser())
 315                         current->euid = euid;
 316                 else {
 317                         current->uid = old_ruid;
 318                         return(-EPERM);
 319                 }
 320         }
 321         if (ruid != (uid_t) -1 ||
 322             (euid != (uid_t) -1 && euid != old_ruid))
 323                 current->suid = current->euid;
 324         return 0;
 325 }
 326 
 327 /*
 328  * setuid() is implemented like SysV w/ SAVED_IDS 
 329  * 
 330  * Note that SAVED_ID's is deficient in that a setuid root program
 331  * like sendmail, for example, cannot set its uid to be a normal 
 332  * user and then switch back, because if you're root, setuid() sets
 333  * the saved uid too.  If you don't like this, blame the bright people
 334  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 335  * will allow a root program to temporarily drop privileges and be able to
 336  * regain them by swapping the real and effective uid.  
 337  */
 338 asmlinkage int sys_setuid(uid_t uid)
     /*  */
 339 {
 340         if (suser())
 341                 current->uid = current->euid = current->suid = uid;
 342         else if ((uid == current->uid) || (uid == current->suid))
 343                 current->euid = uid;
 344         else
 345                 return -EPERM;
 346         return(0);
 347 }
 348 
 349 asmlinkage int sys_times(struct tms * tbuf)
     /*  */
 350 {
 351         if (tbuf) {
 352                 int error = verify_area(VERIFY_WRITE,tbuf,sizeof *tbuf);
 353                 if (error)
 354                         return error;
 355                 put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime);
 356                 put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime);
 357                 put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime);
 358                 put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime);
 359         }
 360         return jiffies;
 361 }
 362 
 363 asmlinkage int sys_brk(unsigned long brk)
     /*  */
 364 {
 365         int freepages;
 366         unsigned long rlim;
 367         unsigned long newbrk, oldbrk;
 368 
 369         if (brk < current->mm->end_code)
 370                 return current->mm->brk;
 371         newbrk = PAGE_ALIGN(brk);
 372         oldbrk = PAGE_ALIGN(current->mm->brk);
 373         if (oldbrk == newbrk)
 374                 return current->mm->brk = brk;
 375 
 376         /*
 377          * Always allow shrinking brk
 378          */
 379         if (brk <= current->mm->brk) {
 380                 current->mm->brk = brk;
 381                 do_munmap(newbrk, oldbrk-newbrk);
 382                 return brk;
 383         }
 384         /*
 385          * Check against rlimit and stack..
 386          */
 387         rlim = current->rlim[RLIMIT_DATA].rlim_cur;
 388         if (rlim >= RLIM_INFINITY)
 389                 rlim = ~0;
 390         if (brk - current->mm->end_code > rlim ||
 391             brk >= current->mm->start_stack - 16384)
 392                 return current->mm->brk;
 393         /*
 394          * stupid algorithm to decide if we have enough memory: while
 395          * simple, it hopefully works in most obvious cases.. Easy to
 396          * fool it, but this should catch most mistakes.
 397          */
 398         freepages = buffermem >> 12;
 399         freepages += nr_free_pages;
 400         freepages += nr_swap_pages;
 401         freepages -= (high_memory - 0x100000) >> 16;
 402         freepages -= (newbrk-oldbrk) >> 12;
 403         if (freepages < 0)
 404                 return current->mm->brk;
 405 #if 0
 406         freepages += current->mm->rss;
 407         freepages -= oldbrk >> 12;
 408         if (freepages < 0)
 409                 return current->mm->brk;
 410 #endif
 411         /*
 412          * Ok, we have probably got enough memory - let it rip.
 413          */
 414         current->mm->brk = brk;
 415         do_mmap(NULL, oldbrk, newbrk-oldbrk,
 416                 PROT_READ|PROT_WRITE|PROT_EXEC,
 417                 MAP_FIXED|MAP_PRIVATE, 0);
 418         return brk;
 419 }
 420 
 421 /*
 422  * This needs some heave checking ...
 423  * I just haven't get the stomach for it. I also don't fully
 424  * understand sessions/pgrp etc. Let somebody who does explain it.
 425  *
 426  * OK, I think I have the protection semantics right.... this is really
 427  * only important on a multi-user system anyway, to make sure one user
 428  * can't send a signal to a process owned by another.  -TYT, 12/12/91
 429  *
 430  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 431  * LBT 04.03.94
 432  */
 433 asmlinkage int sys_setpgid(pid_t pid, pid_t pgid)
     /*  */
 434 {
 435         struct task_struct * p;
 436 
 437         if (!pid)
 438                 pid = current->pid;
 439         if (!pgid)
 440                 pgid = pid;
 441         if (pgid < 0)
 442                 return -EINVAL;
 443         for_each_task(p) {
 444                 if (p->pid == pid)
 445                         goto found_task;
 446         }
 447         return -ESRCH;
 448 
 449 found_task:
 450         if (p->p_pptr == current || p->p_opptr == current) {
 451                 if (p->session != current->session)
 452                         return -EPERM;
 453                 if (p->did_exec)
 454                         return -EACCES;
 455         } else if (p != current)
 456                 return -ESRCH;
 457         if (p->leader)
 458                 return -EPERM;
 459         if (pgid != pid) {
 460                 struct task_struct * tmp;
 461                 for_each_task (tmp) {
 462                         if (tmp->pgrp == pgid &&
 463                          tmp->session == current->session)
 464                                 goto ok_pgid;
 465                 }
 466                 return -EPERM;
 467         }
 468 
 469 ok_pgid:
 470         p->pgrp = pgid;
 471         return 0;
 472 }
 473 
 474 asmlinkage int sys_getpgid(pid_t pid)
     /*  */
 475 {
 476         struct task_struct * p;
 477 
 478         if (!pid)
 479                 return current->pgrp;
 480         for_each_task(p) {
 481                 if (p->pid == pid)
 482                         return p->pgrp;
 483         }
 484         return -ESRCH;
 485 }
 486 
 487 asmlinkage int sys_getpgrp(void)
     /*  */
 488 {
 489         return current->pgrp;
 490 }
 491 
 492 asmlinkage int sys_setsid(void)
     /*  */
 493 {
 494         if (current->leader)
 495                 return -EPERM;
 496         current->leader = 1;
 497         current->session = current->pgrp = current->pid;
 498         current->tty = NULL;
 499         return current->pgrp;
 500 }
 501 
 502 /*
 503  * Supplementary group ID's
 504  */
 505 asmlinkage int sys_getgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 506 {
 507         int i;
 508 
 509         if (gidsetsize) {
 510                 i = verify_area(VERIFY_WRITE, grouplist, sizeof(gid_t) * gidsetsize);
 511                 if (i)
 512                         return i;
 513         }
 514         for (i = 0 ; (i < NGROUPS) && (current->groups[i] != NOGROUP) ; i++) {
 515                 if (!gidsetsize)
 516                         continue;
 517                 if (i >= gidsetsize)
 518                         break;
 519                 put_fs_word(current->groups[i], (short *) grouplist);
 520                 grouplist++;
 521         }
 522         return(i);
 523 }
 524 
 525 asmlinkage int sys_setgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 526 {
 527         int     i;
 528 
 529         if (!suser())
 530                 return -EPERM;
 531         if (gidsetsize > NGROUPS)
 532                 return -EINVAL;
 533         for (i = 0; i < gidsetsize; i++, grouplist++) {
 534                 current->groups[i] = get_fs_word((unsigned short *) grouplist);
 535         }
 536         if (i < NGROUPS)
 537                 current->groups[i] = NOGROUP;
 538         return 0;
 539 }
 540 
 541 int in_group_p(gid_t grp)
     /*  */
 542 {
 543         int     i;
 544 
 545         if (grp == current->egid)
 546                 return 1;
 547 
 548         for (i = 0; i < NGROUPS; i++) {
 549                 if (current->groups[i] == NOGROUP)
 550                         break;
 551                 if (current->groups[i] == grp)
 552                         return 1;
 553         }
 554         return 0;
 555 }
 556 
 557 asmlinkage int sys_newuname(struct new_utsname * name)
     /*  */
 558 {
 559         int error;
 560 
 561         if (!name)
 562                 return -EFAULT;
 563         error = verify_area(VERIFY_WRITE, name, sizeof *name);
 564         if (!error)
 565                 memcpy_tofs(name,&system_utsname,sizeof *name);
 566         return error;
 567 }
 568 
 569 asmlinkage int sys_uname(struct old_utsname * name)
     /*  */
 570 {
 571         int error;
 572         if (!name)
 573                 return -EFAULT;
 574         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 575         if (error)
 576                 return error;
 577         memcpy_tofs(&name->sysname,&system_utsname.sysname,
 578                 sizeof (system_utsname.sysname));
 579         memcpy_tofs(&name->nodename,&system_utsname.nodename,
 580                 sizeof (system_utsname.nodename));
 581         memcpy_tofs(&name->release,&system_utsname.release,
 582                 sizeof (system_utsname.release));
 583         memcpy_tofs(&name->version,&system_utsname.version,
 584                 sizeof (system_utsname.version));
 585         memcpy_tofs(&name->machine,&system_utsname.machine,
 586                 sizeof (system_utsname.machine));
 587         return 0;
 588 }
 589 
 590 asmlinkage int sys_olduname(struct oldold_utsname * name)
     /*  */
 591 {
 592         int error;
 593         if (!name)
 594                 return -EFAULT;
 595         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 596         if (error)
 597                 return error;
 598         memcpy_tofs(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 599         put_fs_byte(0,name->sysname+__OLD_UTS_LEN);
 600         memcpy_tofs(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 601         put_fs_byte(0,name->nodename+__OLD_UTS_LEN);
 602         memcpy_tofs(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 603         put_fs_byte(0,name->release+__OLD_UTS_LEN);
 604         memcpy_tofs(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 605         put_fs_byte(0,name->version+__OLD_UTS_LEN);
 606         memcpy_tofs(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 607         put_fs_byte(0,name->machine+__OLD_UTS_LEN);
 608         return 0;
 609 }
 610 
 611 /*
 612  * Only sethostname; gethostname can be implemented by calling uname()
 613  */
 614 asmlinkage int sys_sethostname(char *name, int len)
     /*  */
 615 {
 616         int     i;
 617         
 618         if (!suser())
 619                 return -EPERM;
 620         if (len > __NEW_UTS_LEN)
 621                 return -EINVAL;
 622         for (i=0; i < len; i++) {
 623                 if ((system_utsname.nodename[i] = get_fs_byte(name+i)) == 0)
 624                         return 0;
 625         }
 626         system_utsname.nodename[i] = 0;
 627         return 0;
 628 }
 629 
 630 /*
 631  * Only setdomainname; getdomainname can be implemented by calling
 632  * uname()
 633  */
 634 asmlinkage int sys_setdomainname(char *name, int len)
     /*  */
 635 {
 636         int     i;
 637         
 638         if (!suser())
 639                 return -EPERM;
 640         if (len > __NEW_UTS_LEN)
 641                 return -EINVAL;
 642         for (i=0; i < len; i++) {
 643                 if ((system_utsname.domainname[i] = get_fs_byte(name+i)) == 0)
 644                         return 0;
 645         }
 646         system_utsname.domainname[i] = 0;
 647         return 0;
 648 }
 649 
 650 asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 651 {
 652         int error;
 653 
 654         if (resource >= RLIM_NLIMITS)
 655                 return -EINVAL;
 656         error = verify_area(VERIFY_WRITE,rlim,sizeof *rlim);
 657         if (error)
 658                 return error;
 659         put_fs_long(current->rlim[resource].rlim_cur, 
 660                     (unsigned long *) rlim);
 661         put_fs_long(current->rlim[resource].rlim_max, 
 662                     ((unsigned long *) rlim)+1);
 663         return 0;       
 664 }
 665 
 666 asmlinkage int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 667 {
 668         struct rlimit new_rlim, *old_rlim;
 669 
 670         if (resource >= RLIM_NLIMITS)
 671                 return -EINVAL;
 672         old_rlim = current->rlim + resource;
 673         new_rlim.rlim_cur = get_fs_long((unsigned long *) rlim);
 674         new_rlim.rlim_max = get_fs_long(((unsigned long *) rlim)+1);
 675         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
 676              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
 677             !suser())
 678                 return -EPERM;
 679         *old_rlim = new_rlim;
 680         return 0;
 681 }
 682 
 683 /*
 684  * It would make sense to put struct rusage in the task_struct,
 685  * except that would make the task_struct be *really big*.  After
 686  * task_struct gets moved into malloc'ed memory, it would
 687  * make sense to do this.  It will make moving the rest of the information
 688  * a lot simpler!  (Which we're not doing right now because we're not
 689  * measuring them yet).
 690  */
 691 int getrusage(struct task_struct *p, int who, struct rusage *ru)
     /*  */
 692 {
 693         int error;
 694         struct rusage r;
 695         unsigned long   *lp, *lpend, *dest;
 696 
 697         error = verify_area(VERIFY_WRITE, ru, sizeof *ru);
 698         if (error)
 699                 return error;
 700         memset((char *) &r, 0, sizeof(r));
 701         switch (who) {
 702                 case RUSAGE_SELF:
 703                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime);
 704                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime);
 705                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime);
 706                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime);
 707                         r.ru_minflt = p->mm->min_flt;
 708                         r.ru_majflt = p->mm->maj_flt;
 709                         break;
 710                 case RUSAGE_CHILDREN:
 711                         r.ru_utime.tv_sec = CT_TO_SECS(p->cutime);
 712                         r.ru_utime.tv_usec = CT_TO_USECS(p->cutime);
 713                         r.ru_stime.tv_sec = CT_TO_SECS(p->cstime);
 714                         r.ru_stime.tv_usec = CT_TO_USECS(p->cstime);
 715                         r.ru_minflt = p->mm->cmin_flt;
 716                         r.ru_majflt = p->mm->cmaj_flt;
 717                         break;
 718                 default:
 719                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime + p->cutime);
 720                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime + p->cutime);
 721                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime + p->cstime);
 722                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime + p->cstime);
 723                         r.ru_minflt = p->mm->min_flt + p->mm->cmin_flt;
 724                         r.ru_majflt = p->mm->maj_flt + p->mm->cmaj_flt;
 725                         break;
 726         }
 727         lp = (unsigned long *) &r;
 728         lpend = (unsigned long *) (&r+1);
 729         dest = (unsigned long *) ru;
 730         for (; lp < lpend; lp++, dest++) 
 731                 put_fs_long(*lp, dest);
 732         return 0;
 733 }
 734 
 735 asmlinkage int sys_getrusage(int who, struct rusage *ru)
     /*  */
 736 {
 737         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
 738                 return -EINVAL;
 739         return getrusage(current, who, ru);
 740 }
 741 
 742 asmlinkage int sys_umask(int mask)
     /*  */
 743 {
 744         int old = current->fs->umask;
 745 
 746         current->fs->umask = mask & S_IRWXUGO;
 747         return (old);
 748 }
/* */
root/kernel/sys.c

DEFINITIONS
