kernel/sys.c

/* */
This source file includes following definitions.
sys_ni_syscall
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
acct_process
sys_acct
sys_phys
sys_lock
sys_mpx
sys_ulimit
sys_old_syscall
sys_setreuid
sys_setuid
sys_setfsuid
sys_setfsgid
sys_times
sys_brk
sys_setpgid
sys_getpgid
sys_getpgrp
sys_getsid
sys_setsid
sys_getgroups
sys_setgroups
in_group_p
sys_newuname
sys_uname
sys_olduname
sys_sethostname
sys_gethostname
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 #include <linux/mm.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/swap.h>
  23 #include <linux/fcntl.h>
  24 #include <linux/acct.h>
  25 #include <linux/tty.h>
  26 #if defined(CONFIG_APM) && defined(CONFIG_APM_POWER_OFF)
  27 #include <linux/apm_bios.h>
  28 #endif
  29 
  30 #include <asm/segment.h>
  31 #include <asm/io.h>
  32 
  33 /*
  34  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
  35  */
  36 int C_A_D = 1;
  37 
  38 extern void adjust_clock(void);
  39 
  40 asmlinkage int sys_ni_syscall(void)
     /*  */
  41 {
  42         return -ENOSYS;
  43 }
  44 
  45 static int proc_sel(struct task_struct *p, int which, int who)
     /*  */
  46 {
  47         if(p->pid)
  48         {
  49                 switch (which) {
  50                         case PRIO_PROCESS:
  51                                 if (!who && p == current)
  52                                         return 1;
  53                                 return(p->pid == who);
  54                         case PRIO_PGRP:
  55                                 if (!who)
  56                                         who = current->pgrp;
  57                                 return(p->pgrp == who);
  58                         case PRIO_USER:
  59                                 if (!who)
  60                                         who = current->uid;
  61                                 return(p->uid == who);
  62                 }
  63         }
  64         return 0;
  65 }
  66 
  67 asmlinkage int sys_setpriority(int which, int who, int niceval)
     /*  */
  68 {
  69         struct task_struct *p;
  70         int error = ESRCH;
  71         unsigned int priority;
  72 
  73         if (which > 2 || which < 0)
  74                 return -EINVAL;
  75 
  76         /* normalize: avoid signed division (rounding problems) */
  77         priority = niceval;
  78         if (niceval < 0)
  79                 priority = -niceval;
  80         if (priority > 20)
  81                 priority = 20;
  82         priority = (priority * DEF_PRIORITY + 10) / 20 + DEF_PRIORITY;
  83 
  84         if (niceval >= 0) {
  85                 priority = 2*DEF_PRIORITY - priority;
  86                 if (!priority)
  87                         priority = 1;
  88         }
  89 
  90         for_each_task(p) {
  91                 if (!proc_sel(p, which, who))
  92                         continue;
  93                 if (p->uid != current->euid &&
  94                         p->uid != current->uid && !suser()) {
  95                         error = EPERM;
  96                         continue;
  97                 }
  98                 if (error == ESRCH)
  99                         error = 0;
 100                 if (priority > p->priority && !suser())
 101                         error = EACCES;
 102                 else
 103                         p->priority = priority;
 104         }
 105         return -error;
 106 }
 107 
 108 /*
 109  * Ugh. To avoid negative return values, "getpriority()" will
 110  * not return the normal nice-value, but a value that has been
 111  * offset by 20 (ie it returns 0..40 instead of -20..20)
 112  */
 113 asmlinkage int sys_getpriority(int which, int who)
     /*  */
 114 {
 115         struct task_struct *p;
 116         long max_prio = -ESRCH;
 117 
 118         if (which > 2 || which < 0)
 119                 return -EINVAL;
 120 
 121         for_each_task (p) {
 122                 if (!proc_sel(p, which, who))
 123                         continue;
 124                 if (p->priority > max_prio)
 125                         max_prio = p->priority;
 126         }
 127 
 128         /* scale the priority from timeslice to 0..40 */
 129         if (max_prio > 0)
 130                 max_prio = (max_prio * 20 + DEF_PRIORITY/2) / DEF_PRIORITY;
 131         return max_prio;
 132 }
 133 
 134 #ifndef __alpha__
 135 
 136 /*
 137  * Why do these exist?  Binary compatibility with some other standard?
 138  * If so, maybe they should be moved into the appropriate arch
 139  * directory.
 140  */
 141 
 142 asmlinkage int sys_profil(void)
     /*  */
 143 {
 144         return -ENOSYS;
 145 }
 146 
 147 asmlinkage int sys_ftime(void)
     /*  */
 148 {
 149         return -ENOSYS;
 150 }
 151 
 152 asmlinkage int sys_break(void)
     /*  */
 153 {
 154         return -ENOSYS;
 155 }
 156 
 157 asmlinkage int sys_stty(void)
     /*  */
 158 {
 159         return -ENOSYS;
 160 }
 161 
 162 asmlinkage int sys_gtty(void)
     /*  */
 163 {
 164         return -ENOSYS;
 165 }
 166 
 167 asmlinkage int sys_prof(void)
     /*  */
 168 {
 169         return -ENOSYS;
 170 }
 171 
 172 #endif
 173 
 174 extern void hard_reset_now(void);
 175 extern asmlinkage sys_kill(int, int);
 176 
 177 /*
 178  * Reboot system call: for obvious reasons only root may call it,
 179  * and even root needs to set up some magic numbers in the registers
 180  * so that some mistake won't make this reboot the whole machine.
 181  * You can also set the meaning of the ctrl-alt-del-key here.
 182  *
 183  * reboot doesn't sync: do that yourself before calling this.
 184  */
 185 asmlinkage int sys_reboot(int magic, int magic_too, int flag)
     /*  */
 186 {
 187         if (!suser())
 188                 return -EPERM;
 189         if (magic != 0xfee1dead || magic_too != 672274793)
 190                 return -EINVAL;
 191         if (flag == 0x01234567)
 192                 hard_reset_now();
 193         else if (flag == 0x89ABCDEF)
 194                 C_A_D = 1;
 195         else if (!flag)
 196                 C_A_D = 0;
 197         else if (flag == 0xCDEF0123) {
 198                 printk(KERN_EMERG "System halted\n");
 199                 sys_kill(-1, SIGKILL);
 200 #if defined(CONFIG_APM) && defined(CONFIG_APM_POWER_OFF)
 201                 apm_set_power_state(APM_STATE_OFF);
 202 #endif
 203                 do_exit(0);
 204         } else
 205                 return -EINVAL;
 206         return (0);
 207 }
 208 
 209 /*
 210  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 211  * As it's called within an interrupt, it may NOT sync: the only choice
 212  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 213  */
 214 void ctrl_alt_del(void)
     /*  */
 215 {
 216         if (C_A_D)
 217                 hard_reset_now();
 218         else
 219                 kill_proc(1, SIGINT, 1);
 220 }
 221         
 222 
 223 /*
 224  * Unprivileged users may change the real gid to the effective gid
 225  * or vice versa.  (BSD-style)
 226  *
 227  * If you set the real gid at all, or set the effective gid to a value not
 228  * equal to the real gid, then the saved gid is set to the new effective gid.
 229  *
 230  * This makes it possible for a setgid program to completely drop its
 231  * privileges, which is often a useful assertion to make when you are doing
 232  * a security audit over a program.
 233  *
 234  * The general idea is that a program which uses just setregid() will be
 235  * 100% compatible with BSD.  A program which uses just setgid() will be
 236  * 100% compatible with POSIX w/ Saved ID's. 
 237  */
 238 asmlinkage int sys_setregid(gid_t rgid, gid_t egid)
     /*  */
 239 {
 240         int old_rgid = current->gid;
 241         int old_egid = current->egid;
 242 
 243         if (rgid != (gid_t) -1) {
 244                 if ((old_rgid == rgid) ||
 245                     (current->egid==rgid) ||
 246                     suser())
 247                         current->gid = rgid;
 248                 else
 249                         return(-EPERM);
 250         }
 251         if (egid != (gid_t) -1) {
 252                 if ((old_rgid == egid) ||
 253                     (current->egid == egid) ||
 254                     (current->sgid == egid) ||
 255                     suser())
 256                         current->fsgid = current->egid = egid;
 257                 else {
 258                         current->gid = old_rgid;
 259                         return(-EPERM);
 260                 }
 261         }
 262         if (rgid != (gid_t) -1 ||
 263             (egid != (gid_t) -1 && egid != old_rgid))
 264                 current->sgid = current->egid;
 265         current->fsgid = current->egid;
 266         if (current->egid != old_egid)
 267                 current->dumpable = 0;
 268         return 0;
 269 }
 270 
 271 /*
 272  * setgid() is implemented like SysV w/ SAVED_IDS 
 273  */
 274 asmlinkage int sys_setgid(gid_t gid)
     /*  */
 275 {
 276         int old_egid = current->egid;
 277 
 278         if (suser())
 279                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 280         else if ((gid == current->gid) || (gid == current->sgid))
 281                 current->egid = current->fsgid = gid;
 282         else
 283                 return -EPERM;
 284         if (current->egid != old_egid)
 285                 current->dumpable = 0;
 286         return 0;
 287 }
 288   
 289 static char acct_active = 0;
 290 static struct file acct_file;
 291 
 292 int acct_process(long exitcode)
     /*  */
 293 {
 294    struct acct ac;
 295    unsigned short fs;
 296 
 297    if (acct_active) {
 298       strncpy(ac.ac_comm, current->comm, ACCT_COMM);
 299       ac.ac_comm[ACCT_COMM-1] = '\0';
 300       ac.ac_utime = current->utime;
 301       ac.ac_stime = current->stime;
 302       ac.ac_btime = CT_TO_SECS(current->start_time) + (xtime.tv_sec - (jiffies / HZ));
 303       ac.ac_etime = CURRENT_TIME - ac.ac_btime;
 304       ac.ac_uid   = current->uid;
 305       ac.ac_gid   = current->gid;
 306       ac.ac_tty   = (current)->tty == NULL ? -1 :
 307           MKDEV(4, current->tty->device);
 308       ac.ac_flag  = 0;
 309       if (current->flags & PF_FORKNOEXEC)
 310          ac.ac_flag |= AFORK;
 311       if (current->flags & PF_SUPERPRIV)
 312          ac.ac_flag |= ASU;
 313       if (current->flags & PF_DUMPCORE)
 314          ac.ac_flag |= ACORE;
 315       if (current->flags & PF_SIGNALED)
 316          ac.ac_flag |= AXSIG;
 317       ac.ac_minflt = current->min_flt;
 318       ac.ac_majflt = current->maj_flt;
 319       ac.ac_exitcode = exitcode;
 320 
 321       /* Kernel segment override */
 322       fs = get_fs();
 323       set_fs(KERNEL_DS);
 324 
 325       acct_file.f_op->write(acct_file.f_inode, &acct_file,
 326                              (char *)&ac, sizeof(struct acct));
 327 
 328       set_fs(fs);
 329    }
 330    return 0;
 331 }
 332 
 333 asmlinkage int sys_acct(const char *name)
     /*  */
 334 {
 335    struct inode *inode = (struct inode *)0;
 336    char *tmp;
 337    int error;
 338 
 339    if (!suser())
 340       return -EPERM;
 341 
 342    if (name == (char *)0) {
 343       if (acct_active) {
 344          if (acct_file.f_op->release)
 345             acct_file.f_op->release(acct_file.f_inode, &acct_file);
 346 
 347          if (acct_file.f_inode != (struct inode *) 0)
 348             iput(acct_file.f_inode);
 349 
 350          acct_active = 0;
 351       }
 352       return 0;
 353    } else {
 354       if (!acct_active) {
 355 
 356          if ((error = getname(name, &tmp)) != 0)
 357             return (error);
 358 
 359          error = open_namei(tmp, O_RDWR, 0600, &inode, 0);
 360          putname(tmp);
 361 
 362          if (error)
 363             return (error);
 364 
 365          if (!S_ISREG(inode->i_mode)) {
 366             iput(inode);
 367             return -EACCES;
 368          }
 369 
 370          if (!inode->i_op || !inode->i_op->default_file_ops || 
 371              !inode->i_op->default_file_ops->write) {
 372             iput(inode);
 373             return -EIO;
 374          }
 375 
 376          acct_file.f_mode = 3;
 377          acct_file.f_flags = 0;
 378          acct_file.f_count = 1;
 379          acct_file.f_inode = inode;
 380          acct_file.f_pos = inode->i_size;
 381          acct_file.f_reada = 0;
 382          acct_file.f_op = inode->i_op->default_file_ops;
 383 
 384          if (acct_file.f_op->open)
 385             if (acct_file.f_op->open(acct_file.f_inode, &acct_file)) {
 386                iput(inode);
 387                return -EIO;
 388             }
 389 
 390          acct_active = 1;
 391          return 0;
 392       } else
 393          return -EBUSY;
 394    }
 395 }
 396 
 397 #ifndef __alpha__
 398 
 399 /*
 400  * Why do these exist?  Binary compatibility with some other standard?
 401  * If so, maybe they should be moved into the appropriate arch
 402  * directory.
 403  */
 404 
 405 asmlinkage int sys_phys(void)
     /*  */
 406 {
 407         return -ENOSYS;
 408 }
 409 
 410 asmlinkage int sys_lock(void)
     /*  */
 411 {
 412         return -ENOSYS;
 413 }
 414 
 415 asmlinkage int sys_mpx(void)
     /*  */
 416 {
 417         return -ENOSYS;
 418 }
 419 
 420 asmlinkage int sys_ulimit(void)
     /*  */
 421 {
 422         return -ENOSYS;
 423 }
 424 
 425 asmlinkage int sys_old_syscall(void)
     /*  */
 426 {
 427         return -ENOSYS;
 428 }
 429 
 430 #endif
 431 
 432 /*
 433  * Unprivileged users may change the real uid to the effective uid
 434  * or vice versa.  (BSD-style)
 435  *
 436  * If you set the real uid at all, or set the effective uid to a value not
 437  * equal to the real uid, then the saved uid is set to the new effective uid.
 438  *
 439  * This makes it possible for a setuid program to completely drop its
 440  * privileges, which is often a useful assertion to make when you are doing
 441  * a security audit over a program.
 442  *
 443  * The general idea is that a program which uses just setreuid() will be
 444  * 100% compatible with BSD.  A program which uses just setuid() will be
 445  * 100% compatible with POSIX w/ Saved ID's. 
 446  */
 447 asmlinkage int sys_setreuid(uid_t ruid, uid_t euid)
     /*  */
 448 {
 449         int old_ruid = current->uid;
 450         int old_euid = current->euid;
 451 
 452         if (ruid != (uid_t) -1) {
 453                 if ((old_ruid == ruid) || 
 454                     (current->euid==ruid) ||
 455                     suser())
 456                         current->uid = ruid;
 457                 else
 458                         return(-EPERM);
 459         }
 460         if (euid != (uid_t) -1) {
 461                 if ((old_ruid == euid) ||
 462                     (current->euid == euid) ||
 463                     (current->suid == euid) ||
 464                     suser())
 465                         current->fsuid = current->euid = euid;
 466                 else {
 467                         current->uid = old_ruid;
 468                         return(-EPERM);
 469                 }
 470         }
 471         if (ruid != (uid_t) -1 ||
 472             (euid != (uid_t) -1 && euid != old_ruid))
 473                 current->suid = current->euid;
 474         current->fsuid = current->euid;
 475         if (current->euid != old_euid)
 476                 current->dumpable = 0;
 477         return 0;
 478 }
 479 
 480 /*
 481  * setuid() is implemented like SysV w/ SAVED_IDS 
 482  * 
 483  * Note that SAVED_ID's is deficient in that a setuid root program
 484  * like sendmail, for example, cannot set its uid to be a normal 
 485  * user and then switch back, because if you're root, setuid() sets
 486  * the saved uid too.  If you don't like this, blame the bright people
 487  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 488  * will allow a root program to temporarily drop privileges and be able to
 489  * regain them by swapping the real and effective uid.  
 490  */
 491 asmlinkage int sys_setuid(uid_t uid)
     /*  */
 492 {
 493         int old_euid = current->euid;
 494 
 495         if (suser())
 496                 current->uid = current->euid = current->suid = current->fsuid = uid;
 497         else if ((uid == current->uid) || (uid == current->suid))
 498                 current->fsuid = current->euid = uid;
 499         else
 500                 return -EPERM;
 501         if (current->euid != old_euid)
 502                 current->dumpable = 0;
 503         return(0);
 504 }
 505 
 506 /*
 507  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 508  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 509  * whatever uid it wants to). It normally shadows "euid", except when
 510  * explicitly set by setfsuid() or for access..
 511  */
 512 asmlinkage int sys_setfsuid(uid_t uid)
     /*  */
 513 {
 514         int old_fsuid = current->fsuid;
 515 
 516         if (uid == current->uid || uid == current->euid ||
 517             uid == current->suid || uid == current->fsuid || suser())
 518                 current->fsuid = uid;
 519         if (current->fsuid != old_fsuid)
 520                 current->dumpable = 0;
 521         return old_fsuid;
 522 }
 523 
 524 /*
 525  * Samma p� svenska..
 526  */
 527 asmlinkage int sys_setfsgid(gid_t gid)
     /*  */
 528 {
 529         int old_fsgid = current->fsgid;
 530 
 531         if (gid == current->gid || gid == current->egid ||
 532             gid == current->sgid || gid == current->fsgid || suser())
 533                 current->fsgid = gid;
 534         if (current->fsgid != old_fsgid)
 535                 current->dumpable = 0;
 536         return old_fsgid;
 537 }
 538 
 539 asmlinkage long sys_times(struct tms * tbuf)
     /*  */
 540 {
 541         if (tbuf) {
 542                 int error = verify_area(VERIFY_WRITE,tbuf,sizeof *tbuf);
 543                 if (error)
 544                         return error;
 545                 put_user(current->utime,&tbuf->tms_utime);
 546                 put_user(current->stime,&tbuf->tms_stime);
 547                 put_user(current->cutime,&tbuf->tms_cutime);
 548                 put_user(current->cstime,&tbuf->tms_cstime);
 549         }
 550         return jiffies;
 551 }
 552 
 553 asmlinkage unsigned long sys_brk(unsigned long brk)
     /*  */
 554 {
 555         int freepages;
 556         unsigned long rlim;
 557         unsigned long newbrk, oldbrk;
 558 
 559         if (brk < current->mm->end_code)
 560                 return current->mm->brk;
 561         newbrk = PAGE_ALIGN(brk);
 562         oldbrk = PAGE_ALIGN(current->mm->brk);
 563         if (oldbrk == newbrk)
 564                 return current->mm->brk = brk;
 565 
 566         /*
 567          * Always allow shrinking brk
 568          */
 569         if (brk <= current->mm->brk) {
 570                 current->mm->brk = brk;
 571                 do_munmap(newbrk, oldbrk-newbrk);
 572                 return brk;
 573         }
 574         /*
 575          * Check against rlimit and stack..
 576          */
 577         rlim = current->rlim[RLIMIT_DATA].rlim_cur;
 578         if (rlim >= RLIM_INFINITY)
 579                 rlim = ~0;
 580         if (brk - current->mm->end_code > rlim)
 581                 return current->mm->brk;
 582         /*
 583          * Check against existing mmap mappings.
 584          */
 585         if (find_vma_intersection(current, oldbrk, newbrk+PAGE_SIZE))
 586                 return current->mm->brk;
 587         /*
 588          * stupid algorithm to decide if we have enough memory: while
 589          * simple, it hopefully works in most obvious cases.. Easy to
 590          * fool it, but this should catch most mistakes.
 591          */
 592         freepages = buffermem >> PAGE_SHIFT;
 593         freepages += page_cache_size;
 594         freepages >>= 1;
 595         freepages += nr_free_pages;
 596         freepages += nr_swap_pages;
 597         freepages -= MAP_NR(high_memory) >> 4;
 598         freepages -= (newbrk-oldbrk) >> PAGE_SHIFT;
 599         if (freepages < 0)
 600                 return current->mm->brk;
 601 #if 0
 602         freepages += current->mm->rss;
 603         freepages -= oldbrk >> 12;
 604         if (freepages < 0)
 605                 return current->mm->brk;
 606 #endif
 607         /*
 608          * Ok, we have probably got enough memory - let it rip.
 609          */
 610         current->mm->brk = brk;
 611         do_mmap(NULL, oldbrk, newbrk-oldbrk,
 612                 PROT_READ|PROT_WRITE|PROT_EXEC,
 613                 MAP_FIXED|MAP_PRIVATE, 0);
 614         return brk;
 615 }
 616 
 617 /*
 618  * This needs some heavy checking ...
 619  * I just haven't the stomach for it. I also don't fully
 620  * understand sessions/pgrp etc. Let somebody who does explain it.
 621  *
 622  * OK, I think I have the protection semantics right.... this is really
 623  * only important on a multi-user system anyway, to make sure one user
 624  * can't send a signal to a process owned by another.  -TYT, 12/12/91
 625  *
 626  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 627  * LBT 04.03.94
 628  */
 629 asmlinkage int sys_setpgid(pid_t pid, pid_t pgid)
     /*  */
 630 {
 631         struct task_struct * p;
 632 
 633         if (!pid)
 634                 pid = current->pid;
 635         if (!pgid)
 636                 pgid = pid;
 637         if (pgid < 0)
 638                 return -EINVAL;
 639         for_each_task(p) {
 640                 if (p->pid == pid)
 641                         goto found_task;
 642         }
 643         return -ESRCH;
 644 
 645 found_task:
 646         if (p->p_pptr == current || p->p_opptr == current) {
 647                 if (p->session != current->session)
 648                         return -EPERM;
 649                 if (p->did_exec)
 650                         return -EACCES;
 651         } else if (p != current)
 652                 return -ESRCH;
 653         if (p->leader)
 654                 return -EPERM;
 655         if (pgid != pid) {
 656                 struct task_struct * tmp;
 657                 for_each_task (tmp) {
 658                         if (tmp->pgrp == pgid &&
 659                          tmp->session == current->session)
 660                                 goto ok_pgid;
 661                 }
 662                 return -EPERM;
 663         }
 664 
 665 ok_pgid:
 666         p->pgrp = pgid;
 667         return 0;
 668 }
 669 
 670 asmlinkage int sys_getpgid(pid_t pid)
     /*  */
 671 {
 672         struct task_struct * p;
 673 
 674         if (!pid)
 675                 return current->pgrp;
 676         for_each_task(p) {
 677                 if (p->pid == pid)
 678                         return p->pgrp;
 679         }
 680         return -ESRCH;
 681 }
 682 
 683 asmlinkage int sys_getpgrp(void)
     /*  */
 684 {
 685         return current->pgrp;
 686 }
 687 
 688 asmlinkage int sys_getsid(pid_t pid)
     /*  */
 689 {
 690         struct task_struct * p;
 691 
 692         if (!pid)
 693                 return current->session;
 694         for_each_task(p) {
 695                 if (p->pid == pid)
 696                         return p->session;
 697         }
 698         return -ESRCH;
 699 }
 700 
 701 asmlinkage int sys_setsid(void)
     /*  */
 702 {
 703         if (current->leader)
 704                 return -EPERM;
 705         current->leader = 1;
 706         current->session = current->pgrp = current->pid;
 707         current->tty = NULL;
 708         current->tty_old_pgrp = 0;
 709         return current->pgrp;
 710 }
 711 
 712 /*
 713  * Supplementary group ID's
 714  */
 715 asmlinkage int sys_getgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 716 {
 717         int i;
 718         int * groups;
 719 
 720         if (gidsetsize) {
 721                 i = verify_area(VERIFY_WRITE, grouplist, sizeof(gid_t) * gidsetsize);
 722                 if (i)
 723                         return i;
 724         }
 725         groups = current->groups;
 726         for (i = 0 ; (i < NGROUPS) && (*groups != NOGROUP) ; i++, groups++) {
 727                 if (!gidsetsize)
 728                         continue;
 729                 if (i >= gidsetsize)
 730                         break;
 731                 put_user(*groups, grouplist);
 732                 grouplist++;
 733         }
 734         return(i);
 735 }
 736 
 737 asmlinkage int sys_setgroups(int gidsetsize, gid_t *grouplist)
     /*  */
 738 {
 739         int     i;
 740 
 741         if (!suser())
 742                 return -EPERM;
 743         if (gidsetsize > NGROUPS)
 744                 return -EINVAL;
 745         i = verify_area(VERIFY_READ, grouplist, sizeof(gid_t) * gidsetsize);
 746         if (i)
 747                 return i;
 748         for (i = 0; i < gidsetsize; i++, grouplist++) {
 749                 current->groups[i] = get_user(grouplist);
 750         }
 751         if (i < NGROUPS)
 752                 current->groups[i] = NOGROUP;
 753         return 0;
 754 }
 755 
 756 int in_group_p(gid_t grp)
     /*  */
 757 {
 758         int     i;
 759 
 760         if (grp == current->fsgid)
 761                 return 1;
 762 
 763         for (i = 0; i < NGROUPS; i++) {
 764                 if (current->groups[i] == NOGROUP)
 765                         break;
 766                 if (current->groups[i] == grp)
 767                         return 1;
 768         }
 769         return 0;
 770 }
 771 
 772 asmlinkage int sys_newuname(struct new_utsname * name)
     /*  */
 773 {
 774         int error;
 775 
 776         if (!name)
 777                 return -EFAULT;
 778         error = verify_area(VERIFY_WRITE, name, sizeof *name);
 779         if (!error)
 780                 memcpy_tofs(name,&system_utsname,sizeof *name);
 781         return error;
 782 }
 783 
 784 #ifndef __alpha__
 785 
 786 /*
 787  * Move these to arch dependent dir since they are for
 788  * backward compatibility only?
 789  */
 790 asmlinkage int sys_uname(struct old_utsname * name)
     /*  */
 791 {
 792         int error;
 793         if (!name)
 794                 return -EFAULT;
 795         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 796         if (error)
 797                 return error;
 798         memcpy_tofs(&name->sysname,&system_utsname.sysname,
 799                 sizeof (system_utsname.sysname));
 800         memcpy_tofs(&name->nodename,&system_utsname.nodename,
 801                 sizeof (system_utsname.nodename));
 802         memcpy_tofs(&name->release,&system_utsname.release,
 803                 sizeof (system_utsname.release));
 804         memcpy_tofs(&name->version,&system_utsname.version,
 805                 sizeof (system_utsname.version));
 806         memcpy_tofs(&name->machine,&system_utsname.machine,
 807                 sizeof (system_utsname.machine));
 808         return 0;
 809 }
 810 
 811 asmlinkage int sys_olduname(struct oldold_utsname * name)
     /*  */
 812 {
 813         int error;
 814         if (!name)
 815                 return -EFAULT;
 816         error = verify_area(VERIFY_WRITE, name,sizeof *name);
 817         if (error)
 818                 return error;
 819         memcpy_tofs(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 820         put_user(0,name->sysname+__OLD_UTS_LEN);
 821         memcpy_tofs(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 822         put_user(0,name->nodename+__OLD_UTS_LEN);
 823         memcpy_tofs(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 824         put_user(0,name->release+__OLD_UTS_LEN);
 825         memcpy_tofs(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 826         put_user(0,name->version+__OLD_UTS_LEN);
 827         memcpy_tofs(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 828         put_user(0,name->machine+__OLD_UTS_LEN);
 829         return 0;
 830 }
 831 
 832 #endif
 833 
 834 asmlinkage int sys_sethostname(char *name, int len)
     /*  */
 835 {
 836         int error;
 837 
 838         if (!suser())
 839                 return -EPERM;
 840         if (len < 0 || len > __NEW_UTS_LEN)
 841                 return -EINVAL;
 842         error = verify_area(VERIFY_READ, name, len);
 843         if (error)
 844                 return error;
 845         memcpy_fromfs(system_utsname.nodename, name, len);
 846         system_utsname.nodename[len] = 0;
 847         return 0;
 848 }
 849 
 850 asmlinkage int sys_gethostname(char *name, int len)
     /*  */
 851 {
 852         int i;
 853 
 854         if (len < 0)
 855                 return -EINVAL;
 856         i = verify_area(VERIFY_WRITE, name, len);
 857         if (i)
 858                 return i;
 859         i = 1+strlen(system_utsname.nodename);
 860         if (i > len)
 861                 i = len;
 862         memcpy_tofs(name, system_utsname.nodename, i);
 863         return 0;
 864 }
 865 
 866 /*
 867  * Only setdomainname; getdomainname can be implemented by calling
 868  * uname()
 869  */
 870 asmlinkage int sys_setdomainname(char *name, int len)
     /*  */
 871 {
 872         int error;
 873         
 874         if (!suser())
 875                 return -EPERM;
 876         if (len < 0 || len > __NEW_UTS_LEN)
 877                 return -EINVAL;
 878         error = verify_area(VERIFY_READ, name, len);
 879         if (error)
 880                 return error;
 881         memcpy_fromfs(system_utsname.domainname, name, len);
 882         system_utsname.domainname[len] = 0;
 883         return 0;
 884 }
 885 
 886 asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 887 {
 888         int error;
 889 
 890         if (resource >= RLIM_NLIMITS)
 891                 return -EINVAL;
 892         error = verify_area(VERIFY_WRITE,rlim,sizeof *rlim);
 893         if (error)
 894                 return error;
 895         memcpy_tofs(rlim, current->rlim + resource, sizeof(*rlim));
 896         return 0;       
 897 }
 898 
 899 asmlinkage int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
     /*  */
 900 {
 901         struct rlimit new_rlim, *old_rlim;
 902         int err;
 903 
 904         if (resource >= RLIM_NLIMITS)
 905                 return -EINVAL;
 906         err = verify_area(VERIFY_READ, rlim, sizeof(*rlim));
 907         if (err)
 908                 return err;
 909         memcpy_fromfs(&new_rlim, rlim, sizeof(*rlim));
 910         old_rlim = current->rlim + resource;
 911         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
 912              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
 913             !suser())
 914                 return -EPERM;
 915         if (resource == RLIMIT_NOFILE) {
 916                 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
 917                         return -EPERM;
 918         }
 919         *old_rlim = new_rlim;
 920         return 0;
 921 }
 922 
 923 /*
 924  * It would make sense to put struct rusage in the task_struct,
 925  * except that would make the task_struct be *really big*.  After
 926  * task_struct gets moved into malloc'ed memory, it would
 927  * make sense to do this.  It will make moving the rest of the information
 928  * a lot simpler!  (Which we're not doing right now because we're not
 929  * measuring them yet).
 930  */
 931 int getrusage(struct task_struct *p, int who, struct rusage *ru)
     /*  */
 932 {
 933         int error;
 934         struct rusage r;
 935 
 936         error = verify_area(VERIFY_WRITE, ru, sizeof *ru);
 937         if (error)
 938                 return error;
 939         memset((char *) &r, 0, sizeof(r));
 940         switch (who) {
 941                 case RUSAGE_SELF:
 942                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime);
 943                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime);
 944                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime);
 945                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime);
 946                         r.ru_minflt = p->min_flt;
 947                         r.ru_majflt = p->maj_flt;
 948                         r.ru_nswap = p->nswap;
 949                         break;
 950                 case RUSAGE_CHILDREN:
 951                         r.ru_utime.tv_sec = CT_TO_SECS(p->cutime);
 952                         r.ru_utime.tv_usec = CT_TO_USECS(p->cutime);
 953                         r.ru_stime.tv_sec = CT_TO_SECS(p->cstime);
 954                         r.ru_stime.tv_usec = CT_TO_USECS(p->cstime);
 955                         r.ru_minflt = p->cmin_flt;
 956                         r.ru_majflt = p->cmaj_flt;
 957                         r.ru_nswap = p->cnswap;
 958                         break;
 959                 default:
 960                         r.ru_utime.tv_sec = CT_TO_SECS(p->utime + p->cutime);
 961                         r.ru_utime.tv_usec = CT_TO_USECS(p->utime + p->cutime);
 962                         r.ru_stime.tv_sec = CT_TO_SECS(p->stime + p->cstime);
 963                         r.ru_stime.tv_usec = CT_TO_USECS(p->stime + p->cstime);
 964                         r.ru_minflt = p->min_flt + p->cmin_flt;
 965                         r.ru_majflt = p->maj_flt + p->cmaj_flt;
 966                         r.ru_nswap = p->nswap + p->cnswap;
 967                         break;
 968         }
 969         memcpy_tofs(ru, &r, sizeof(r));
 970         return 0;
 971 }
 972 
 973 asmlinkage int sys_getrusage(int who, struct rusage *ru)
     /*  */
 974 {
 975         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
 976                 return -EINVAL;
 977         return getrusage(current, who, ru);
 978 }
 979 
 980 asmlinkage int sys_umask(int mask)
     /*  */
 981 {
 982         int old = current->fs->umask;
 983 
 984         current->fs->umask = mask & S_IRWXUGO;
 985         return (old);
 986 }
/* */
root/kernel/sys.c

DEFINITIONS
