kernel/sys.c

   1 /*
   2  *  linux/kernel/sys.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/config.h>
   8 #include <linux/compat.h>
   9 #include <linux/module.h>
  10 #include <linux/mm.h>
  11 #include <linux/utsname.h>
  12 #include <linux/mman.h>
  13 #include <linux/smp_lock.h>
  14 #include <linux/notifier.h>
  15 #include <linux/kmod.h>
  16 #include <linux/reboot.h>
  17 #include <linux/prctl.h>
  18 #include <linux/init.h>
  19 #include <linux/highuid.h>
  20 #include <linux/fs.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/device.h>
  23 #include <linux/times.h>
  24 #include <linux/security.h>
  25 #include <linux/dcookies.h>
  26 #include <linux/suspend.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/io.h>
  30 #include <asm/unistd.h>
  31
  32 #ifndef SET_UNALIGN_CTL
  33 # define SET_UNALIGN_CTL(a,b)   (-EINVAL)
  34 #endif
  35 #ifndef GET_UNALIGN_CTL
  36 # define GET_UNALIGN_CTL(a,b)   (-EINVAL)
  37 #endif
  38 #ifndef SET_FPEMU_CTL
  39 # define SET_FPEMU_CTL(a,b)     (-EINVAL)
  40 #endif
  41 #ifndef GET_FPEMU_CTL
  42 # define GET_FPEMU_CTL(a,b)     (-EINVAL)
  43 #endif
  44 #ifndef SET_FPEXC_CTL
  45 # define SET_FPEXC_CTL(a,b)     (-EINVAL)
  46 #endif
  47 #ifndef GET_FPEXC_CTL
  48 # define GET_FPEXC_CTL(a,b)     (-EINVAL)
  49 #endif
  50
  51 /*
  52  * this is where the system-wide overflow UID and GID are defined, for
  53  * architectures that now have 32-bit UID/GID but didn't in the past
  54  */
  55
  56 int overflowuid = DEFAULT_OVERFLOWUID;
  57 int overflowgid = DEFAULT_OVERFLOWGID;
  58
  59 #ifdef CONFIG_UID16
  60 EXPORT_SYMBOL(overflowuid);
  61 EXPORT_SYMBOL(overflowgid);
  62 #endif
  63
  64 /*
  65  * the same as above, but for filesystems which can only store a 16-bit
  66  * UID and GID. as such, this is needed on all architectures
  67  */
  68
  69 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
  70 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
  71
  72 EXPORT_SYMBOL(fs_overflowuid);
  73 EXPORT_SYMBOL(fs_overflowgid);
  74
  75 /*
  76  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
  77  */
  78
  79 int C_A_D = 1;
  80 int cad_pid = 1;
  81
  82 /*
  83  *      Notifier list for kernel code which wants to be called
  84  *      at shutdown. This is used to stop any idling DMA operations
  85  *      and the like.
  86  */
  87
  88 static struct notifier_block *reboot_notifier_list;
  89 rwlock_t notifier_lock = RW_LOCK_UNLOCKED;
  90
  91 /**
  92  *      notifier_chain_register - Add notifier to a notifier chain
  93  *      @list: Pointer to root list pointer
  94  *      @n: New entry in notifier chain
  95  *
  96  *      Adds a notifier to a notifier chain.
  97  *
  98  *      Currently always returns zero.
  99  */
 100
 101 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
 102 {
 103         write_lock(&notifier_lock);
 104         while(*list)
 105         {
 106                 if(n->priority > (*list)->priority)
 107                         break;
 108                 list= &((*list)->next);
 109         }
 110         n->next = *list;
 111         *list=n;
 112         write_unlock(&notifier_lock);
 113         return 0;
 114 }
 115
 116 EXPORT_SYMBOL(notifier_chain_register);
 117
 118 /**
 119  *      notifier_chain_unregister - Remove notifier from a notifier chain
 120  *      @nl: Pointer to root list pointer
 121  *      @n: New entry in notifier chain
 122  *
 123  *      Removes a notifier from a notifier chain.
 124  *
 125  *      Returns zero on success, or %-ENOENT on failure.
 126  */
 127
 128 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
 129 {
 130         write_lock(&notifier_lock);
 131         while((*nl)!=NULL)
 132         {
 133                 if((*nl)==n)
 134                 {
 135                         *nl=n->next;
 136                         write_unlock(&notifier_lock);
 137                         return 0;
 138                 }
 139                 nl=&((*nl)->next);
 140         }
 141         write_unlock(&notifier_lock);
 142         return -ENOENT;
 143 }
 144
 145 EXPORT_SYMBOL(notifier_chain_unregister);
 146
 147 /**
 148  *      notifier_call_chain - Call functions in a notifier chain
 149  *      @n: Pointer to root pointer of notifier chain
 150  *      @val: Value passed unmodified to notifier function
 151  *      @v: Pointer passed unmodified to notifier function
 152  *
 153  *      Calls each function in a notifier chain in turn.
 154  *
 155  *      If the return value of the notifier can be and'd
 156  *      with %NOTIFY_STOP_MASK, then notifier_call_chain
 157  *      will return immediately, with the return value of
 158  *      the notifier function which halted execution.
 159  *      Otherwise, the return value is the return value
 160  *      of the last notifier function called.
 161  */
 162
 163 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
 164 {
 165         int ret=NOTIFY_DONE;
 166         struct notifier_block *nb = *n;
 167
 168         while(nb)
 169         {
 170                 ret=nb->notifier_call(nb,val,v);
 171                 if(ret&NOTIFY_STOP_MASK)
 172                 {
 173                         return ret;
 174                 }
 175                 nb=nb->next;
 176         }
 177         return ret;
 178 }
 179
 180 EXPORT_SYMBOL(notifier_call_chain);
 181
 182 /**
 183  *      register_reboot_notifier - Register function to be called at reboot time
 184  *      @nb: Info about notifier function to be called
 185  *
 186  *      Registers a function with the list of functions
 187  *      to be called at reboot time.
 188  *
 189  *      Currently always returns zero, as notifier_chain_register
 190  *      always returns zero.
 191  */
 192
 193 int register_reboot_notifier(struct notifier_block * nb)
 194 {
 195         return notifier_chain_register(&reboot_notifier_list, nb);
 196 }
 197
 198 EXPORT_SYMBOL(register_reboot_notifier);
 199
 200 /**
 201  *      unregister_reboot_notifier - Unregister previously registered reboot notifier
 202  *      @nb: Hook to be unregistered
 203  *
 204  *      Unregisters a previously registered reboot
 205  *      notifier function.
 206  *
 207  *      Returns zero on success, or %-ENOENT on failure.
 208  */
 209
 210 int unregister_reboot_notifier(struct notifier_block * nb)
 211 {
 212         return notifier_chain_unregister(&reboot_notifier_list, nb);
 213 }
 214
 215 EXPORT_SYMBOL(unregister_reboot_notifier);
 216
 217 asmlinkage long sys_ni_syscall(void)
 218 {
 219         return -ENOSYS;
 220 }
 221
 222 cond_syscall(sys_nfsservctl)
 223 cond_syscall(sys_quotactl)
 224 cond_syscall(sys_acct)
 225 cond_syscall(sys_lookup_dcookie)
 226 cond_syscall(sys_swapon)
 227 cond_syscall(sys_swapoff)
 228 cond_syscall(sys_init_module)
 229 cond_syscall(sys_delete_module)
 230 cond_syscall(sys_socketpair)
 231 cond_syscall(sys_bind)
 232 cond_syscall(sys_listen)
 233 cond_syscall(sys_accept)
 234 cond_syscall(sys_connect)
 235 cond_syscall(sys_getsockname)
 236 cond_syscall(sys_getpeername)
 237 cond_syscall(sys_sendto)
 238 cond_syscall(sys_send)
 239 cond_syscall(sys_recvfrom)
 240 cond_syscall(sys_recv)
 241 cond_syscall(sys_socket)
 242 cond_syscall(sys_setsockopt)
 243 cond_syscall(sys_getsockopt)
 244 cond_syscall(sys_shutdown)
 245 cond_syscall(sys_sendmsg)
 246 cond_syscall(sys_recvmsg)
 247 cond_syscall(sys_socketcall)
 248 cond_syscall(sys_futex)
 249 cond_syscall(compat_sys_futex)
 250 cond_syscall(sys_epoll_create)
 251 cond_syscall(sys_epoll_ctl)
 252 cond_syscall(sys_epoll_wait)
 253 cond_syscall(sys_semget)
 254 cond_syscall(sys_semop)
 255 cond_syscall(sys_semtimedop)
 256 cond_syscall(sys_semctl)
 257 cond_syscall(sys_msgget)
 258 cond_syscall(sys_msgsnd)
 259 cond_syscall(sys_msgrcv)
 260 cond_syscall(sys_msgctl)
 261 cond_syscall(sys_shmget)
 262 cond_syscall(sys_shmdt)
 263 cond_syscall(sys_shmctl)
 264 cond_syscall(sys_mq_open)
 265 cond_syscall(sys_mq_unlink)
 266 cond_syscall(sys_mq_timedsend)
 267 cond_syscall(sys_mq_timedreceive)
 268 cond_syscall(sys_mq_notify)
 269 cond_syscall(sys_mq_getsetattr)
 270 cond_syscall(compat_sys_mq_open)
 271 cond_syscall(compat_sys_mq_timedsend)
 272 cond_syscall(compat_sys_mq_timedreceive)
 273 cond_syscall(compat_sys_mq_notify)
 274 cond_syscall(compat_sys_mq_getsetattr)
 275 cond_syscall(sys_mbind)
 276 cond_syscall(sys_get_mempolicy)
 277 cond_syscall(sys_set_mempolicy)
 278
 279 /* arch-specific weak syscall entries */
 280 cond_syscall(sys_pciconfig_read)
 281 cond_syscall(sys_pciconfig_write)
 282 cond_syscall(sys_pciconfig_iobase)
 283
 284 static int set_one_prio(struct task_struct *p, int niceval, int error)
 285 {
 286         int no_nice;
 287
 288         if (p->uid != current->euid &&
 289                 p->uid != current->uid && !capable(CAP_SYS_NICE)) {
 290                 error = -EPERM;
 291                 goto out;
 292         }
 293         if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) {
 294                 error = -EACCES;
 295                 goto out;
 296         }
 297         no_nice = security_task_setnice(p, niceval);
 298         if (no_nice) {
 299                 error = no_nice;
 300                 goto out;
 301         }
 302         if (error == -ESRCH)
 303                 error = 0;
 304         set_user_nice(p, niceval);
 305 out:
 306         return error;
 307 }
 308
 309 asmlinkage long sys_setpriority(int which, int who, int niceval)
 310 {
 311         struct task_struct *g, *p;
 312         struct user_struct *user;
 313         struct pid *pid;
 314         struct list_head *l;
 315         int error = -EINVAL;
 316
 317         if (which > 2 || which < 0)
 318                 goto out;
 319
 320         /* normalize: avoid signed division (rounding problems) */
 321         error = -ESRCH;
 322         if (niceval < -20)
 323                 niceval = -20;
 324         if (niceval > 19)
 325                 niceval = 19;
 326
 327         read_lock(&tasklist_lock);
 328         switch (which) {
 329                 case PRIO_PROCESS:
 330                         if (!who)
 331                                 who = current->pid;
 332                         p = find_task_by_pid(who);
 333                         if (p)
 334                                 error = set_one_prio(p, niceval, error);
 335                         break;
 336                 case PRIO_PGRP:
 337                         if (!who)
 338                                 who = process_group(current);
 339                         for_each_task_pid(who, PIDTYPE_PGID, p, l, pid)
 340                                 error = set_one_prio(p, niceval, error);
 341                         break;
 342                 case PRIO_USER:
 343                         if (!who)
 344                                 user = current->user;
 345                         else
 346                                 user = find_user(vx_current_xid(), who);
 347
 348                         if (!user)
 349                                 goto out_unlock;
 350
 351                         do_each_thread(g, p)
 352                                 if (p->uid == who)
 353                                         error = set_one_prio(p, niceval, error);
 354                         while_each_thread(g, p);
 355                         if (who)
 356                                 free_uid(user);         /* For find_user() */
 357                         break;
 358         }
 359 out_unlock:
 360         read_unlock(&tasklist_lock);
 361 out:
 362         return error;
 363 }
 364
 365 /*
 366  * Ugh. To avoid negative return values, "getpriority()" will
 367  * not return the normal nice-value, but a negated value that
 368  * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 369  * to stay compatible.
 370  */
 371 asmlinkage long sys_getpriority(int which, int who)
 372 {
 373         struct task_struct *g, *p;
 374         struct list_head *l;
 375         struct pid *pid;
 376         struct user_struct *user;
 377         long niceval, retval = -ESRCH;
 378
 379         if (which > 2 || which < 0)
 380                 return -EINVAL;
 381
 382         read_lock(&tasklist_lock);
 383         switch (which) {
 384                 case PRIO_PROCESS:
 385                         if (!who)
 386                                 who = current->pid;
 387                         p = find_task_by_pid(who);
 388                         if (p) {
 389                                 niceval = 20 - task_nice(p);
 390                                 if (niceval > retval)
 391                                         retval = niceval;
 392                         }
 393                         break;
 394                 case PRIO_PGRP:
 395                         if (!who)
 396                                 who = process_group(current);
 397                         for_each_task_pid(who, PIDTYPE_PGID, p, l, pid) {
 398                                 niceval = 20 - task_nice(p);
 399                                 if (niceval > retval)
 400                                         retval = niceval;
 401                         }
 402                         break;
 403                 case PRIO_USER:
 404                         if (!who)
 405                                 user = current->user;
 406                         else
 407                                 user = find_user(vx_current_xid(), who);
 408
 409                         if (!user)
 410                                 goto out_unlock;
 411
 412                         do_each_thread(g, p)
 413                                 if (p->uid == who) {
 414                                         niceval = 20 - task_nice(p);
 415                                         if (niceval > retval)
 416                                                 retval = niceval;
 417                                 }
 418                         while_each_thread(g, p);
 419                         if (who)
 420                                 free_uid(user);         /* for find_user() */
 421                         break;
 422         }
 423 out_unlock:
 424         read_unlock(&tasklist_lock);
 425
 426         return retval;
 427 }
 428
 429 /*
 430  *      vshelper path is set via /proc/sys
 431  *      invoked by vserver sys_reboot(), with
 432  *      the following arguments
 433  *
 434  *      argv [0] = vshelper_path;
 435  *      argv [1] = action: "restart", "halt", "poweroff", ...
 436  *      argv [2] = context identifier
 437  *      argv [3] = additional argument (restart2)
 438  *
 439  *      envp [*] = type-specific parameters
 440  */
 441 char vshelper_path[255] = "/sbin/vshelper";
 442
 443 long vs_reboot(unsigned int cmd, void * arg)
 444 {
 445         char id_buf[8], cmd_buf[32];
 446         char uid_buf[32], pid_buf[32];
 447         char buffer[256];
 448
 449         char *argv[] = {vshelper_path, NULL, id_buf, NULL, 0};
 450         char *envp[] = {"HOME=/", "TERM=linux",
 451                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 452                         uid_buf, pid_buf, cmd_buf, 0};
 453
 454         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
 455
 456         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 457         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
 458         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
 459
 460         switch (cmd) {
 461         case LINUX_REBOOT_CMD_RESTART:
 462                 argv[1] = "restart";
 463                 break;
 464
 465         case LINUX_REBOOT_CMD_HALT:
 466                 argv[1] = "halt";
 467                 break;
 468
 469         case LINUX_REBOOT_CMD_POWER_OFF:
 470                 argv[1] = "poweroff";
 471                 break;
 472
 473         case LINUX_REBOOT_CMD_SW_SUSPEND:
 474                 argv[1] = "swsusp";
 475                 break;
 476
 477         case LINUX_REBOOT_CMD_RESTART2:
 478                 if (strncpy_from_user(&buffer[0], (char *)arg, sizeof(buffer) - 1) < 0)
 479                         return -EFAULT;
 480                 argv[3] = buffer;
 481         default:
 482                 argv[1] = "restart2";
 483                 break;
 484         }
 485
 486         /* maybe we should wait ? */
 487         if (call_usermodehelper(*argv, argv, envp, 0)) {
 488                 printk( KERN_WARNING
 489                         "vs_reboot(): failed to exec (%s %s %s %s)\n",
 490                         vshelper_path, argv[1], argv[2], argv[3]);
 491                 return -EPERM;
 492         }
 493         return 0;
 494 }
 495
 496 /*
 497  * Reboot system call: for obvious reasons only root may call it,
 498  * and even root needs to set up some magic numbers in the registers
 499  * so that some mistake won't make this reboot the whole machine.
 500  * You can also set the meaning of the ctrl-alt-del-key here.
 501  *
 502  * reboot doesn't sync: do that yourself before calling this.
 503  */
 504 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
 505 {
 506         char buffer[256];
 507
 508         /* We only trust the superuser with rebooting the system. */
 509         if (!capable(CAP_SYS_BOOT))
 510                 return -EPERM;
 511
 512         /* For safety, we require "magic" arguments. */
 513         if (magic1 != LINUX_REBOOT_MAGIC1 ||
 514             (magic2 != LINUX_REBOOT_MAGIC2 &&
 515                         magic2 != LINUX_REBOOT_MAGIC2A &&
 516                         magic2 != LINUX_REBOOT_MAGIC2B &&
 517                         magic2 != LINUX_REBOOT_MAGIC2C))
 518                 return -EINVAL;
 519
 520         if (!vx_check(0, VX_ADMIN|VX_WATCH))
 521                 return vs_reboot(cmd, arg);
 522
 523         lock_kernel();
 524         switch (cmd) {
 525         case LINUX_REBOOT_CMD_RESTART:
 526                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 527                 system_state = SYSTEM_RESTART;
 528                 device_shutdown();
 529                 printk(KERN_EMERG "Restarting system.\n");
 530                 machine_restart(NULL);
 531                 break;
 532
 533         case LINUX_REBOOT_CMD_CAD_ON:
 534                 C_A_D = 1;
 535                 break;
 536
 537         case LINUX_REBOOT_CMD_CAD_OFF:
 538                 C_A_D = 0;
 539                 break;
 540
 541         case LINUX_REBOOT_CMD_HALT:
 542                 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
 543                 system_state = SYSTEM_HALT;
 544                 device_shutdown();
 545                 printk(KERN_EMERG "System halted.\n");
 546                 machine_halt();
 547                 unlock_kernel();
 548                 do_exit(0);
 549                 break;
 550
 551         case LINUX_REBOOT_CMD_POWER_OFF:
 552                 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
 553                 system_state = SYSTEM_POWER_OFF;
 554                 device_shutdown();
 555                 printk(KERN_EMERG "Power down.\n");
 556                 machine_power_off();
 557                 unlock_kernel();
 558                 do_exit(0);
 559                 break;
 560
 561         case LINUX_REBOOT_CMD_RESTART2:
 562                 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
 563                         unlock_kernel();
 564                         return -EFAULT;
 565                 }
 566                 buffer[sizeof(buffer) - 1] = '\0';
 567
 568                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
 569                 system_state = SYSTEM_RESTART;
 570                 device_shutdown();
 571                 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
 572                 machine_restart(buffer);
 573                 break;
 574
 575 #ifdef CONFIG_SOFTWARE_SUSPEND
 576         case LINUX_REBOOT_CMD_SW_SUSPEND:
 577                 {
 578                         int ret = software_suspend();
 579                         unlock_kernel();
 580                         return ret;
 581                 }
 582 #endif
 583
 584         default:
 585                 unlock_kernel();
 586                 return -EINVAL;
 587         }
 588         unlock_kernel();
 589         return 0;
 590 }
 591
 592 static void deferred_cad(void *dummy)
 593 {
 594         notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 595         machine_restart(NULL);
 596 }
 597
 598 /*
 599  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 600  * As it's called within an interrupt, it may NOT sync: the only choice
 601  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 602  */
 603 void ctrl_alt_del(void)
 604 {
 605         static DECLARE_WORK(cad_work, deferred_cad, NULL);
 606
 607         if (C_A_D)
 608                 schedule_work(&cad_work);
 609         else
 610                 kill_proc(cad_pid, SIGINT, 1);
 611 }
 612
 613
 614 /*
 615  * Unprivileged users may change the real gid to the effective gid
 616  * or vice versa.  (BSD-style)
 617  *
 618  * If you set the real gid at all, or set the effective gid to a value not
 619  * equal to the real gid, then the saved gid is set to the new effective gid.
 620  *
 621  * This makes it possible for a setgid program to completely drop its
 622  * privileges, which is often a useful assertion to make when you are doing
 623  * a security audit over a program.
 624  *
 625  * The general idea is that a program which uses just setregid() will be
 626  * 100% compatible with BSD.  A program which uses just setgid() will be
 627  * 100% compatible with POSIX with saved IDs.
 628  *
 629  * SMP: There are not races, the GIDs are checked only by filesystem
 630  *      operations (as far as semantic preservation is concerned).
 631  */
 632 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
 633 {
 634         int old_rgid = current->gid;
 635         int old_egid = current->egid;
 636         int new_rgid = old_rgid;
 637         int new_egid = old_egid;
 638         int retval;
 639
 640         retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
 641         if (retval)
 642                 return retval;
 643
 644         if (rgid != (gid_t) -1) {
 645                 if ((old_rgid == rgid) ||
 646                     (current->egid==rgid) ||
 647                     capable(CAP_SETGID))
 648                         new_rgid = rgid;
 649                 else
 650                         return -EPERM;
 651         }
 652         if (egid != (gid_t) -1) {
 653                 if ((old_rgid == egid) ||
 654                     (current->egid == egid) ||
 655                     (current->sgid == egid) ||
 656                     capable(CAP_SETGID))
 657                         new_egid = egid;
 658                 else {
 659                         return -EPERM;
 660                 }
 661         }
 662         if (new_egid != old_egid)
 663         {
 664                 current->mm->dumpable = 0;
 665                 wmb();
 666         }
 667         if (rgid != (gid_t) -1 ||
 668             (egid != (gid_t) -1 && egid != old_rgid))
 669                 current->sgid = new_egid;
 670         current->fsgid = new_egid;
 671         current->egid = new_egid;
 672         current->gid = new_rgid;
 673         return 0;
 674 }
 675
 676 /*
 677  * setgid() is implemented like SysV w/ SAVED_IDS
 678  *
 679  * SMP: Same implicit races as above.
 680  */
 681 asmlinkage long sys_setgid(gid_t gid)
 682 {
 683         int old_egid = current->egid;
 684         int retval;
 685
 686         retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
 687         if (retval)
 688                 return retval;
 689
 690         if (capable(CAP_SETGID))
 691         {
 692                 if(old_egid != gid)
 693                 {
 694                         current->mm->dumpable=0;
 695                         wmb();
 696                 }
 697                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 698         }
 699         else if ((gid == current->gid) || (gid == current->sgid))
 700         {
 701                 if(old_egid != gid)
 702                 {
 703                         current->mm->dumpable=0;
 704                         wmb();
 705                 }
 706                 current->egid = current->fsgid = gid;
 707         }
 708         else
 709                 return -EPERM;
 710         return 0;
 711 }
 712
 713 static int set_user(uid_t new_ruid, int dumpclear)
 714 {
 715         struct user_struct *new_user;
 716
 717         new_user = alloc_uid(vx_current_xid(), new_ruid);
 718         if (!new_user)
 719                 return -EAGAIN;
 720
 721         if (atomic_read(&new_user->processes) >=
 722                                 current->rlim[RLIMIT_NPROC].rlim_cur &&
 723                         new_user != &root_user) {
 724                 free_uid(new_user);
 725                 return -EAGAIN;
 726         }
 727
 728         switch_uid(new_user);
 729
 730         if(dumpclear)
 731         {
 732                 current->mm->dumpable = 0;
 733                 wmb();
 734         }
 735         current->uid = new_ruid;
 736         return 0;
 737 }
 738
 739 /*
 740  * Unprivileged users may change the real uid to the effective uid
 741  * or vice versa.  (BSD-style)
 742  *
 743  * If you set the real uid at all, or set the effective uid to a value not
 744  * equal to the real uid, then the saved uid is set to the new effective uid.
 745  *
 746  * This makes it possible for a setuid program to completely drop its
 747  * privileges, which is often a useful assertion to make when you are doing
 748  * a security audit over a program.
 749  *
 750  * The general idea is that a program which uses just setreuid() will be
 751  * 100% compatible with BSD.  A program which uses just setuid() will be
 752  * 100% compatible with POSIX with saved IDs.
 753  */
 754 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
 755 {
 756         int old_ruid, old_euid, old_suid, new_ruid, new_euid;
 757         int retval;
 758
 759         retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
 760         if (retval)
 761                 return retval;
 762
 763         new_ruid = old_ruid = current->uid;
 764         new_euid = old_euid = current->euid;
 765         old_suid = current->suid;
 766
 767         if (ruid != (uid_t) -1) {
 768                 new_ruid = ruid;
 769                 if ((old_ruid != ruid) &&
 770                     (current->euid != ruid) &&
 771                     !capable(CAP_SETUID))
 772                         return -EPERM;
 773         }
 774
 775         if (euid != (uid_t) -1) {
 776                 new_euid = euid;
 777                 if ((old_ruid != euid) &&
 778                     (current->euid != euid) &&
 779                     (current->suid != euid) &&
 780                     !capable(CAP_SETUID))
 781                         return -EPERM;
 782         }
 783
 784         if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
 785                 return -EAGAIN;
 786
 787         if (new_euid != old_euid)
 788         {
 789                 current->mm->dumpable=0;
 790                 wmb();
 791         }
 792         current->fsuid = current->euid = new_euid;
 793         if (ruid != (uid_t) -1 ||
 794             (euid != (uid_t) -1 && euid != old_ruid))
 795                 current->suid = current->euid;
 796         current->fsuid = current->euid;
 797
 798         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
 799 }
 800
 801
 802
 803 /*
 804  * setuid() is implemented like SysV with SAVED_IDS
 805  *
 806  * Note that SAVED_ID's is deficient in that a setuid root program
 807  * like sendmail, for example, cannot set its uid to be a normal
 808  * user and then switch back, because if you're root, setuid() sets
 809  * the saved uid too.  If you don't like this, blame the bright people
 810  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 811  * will allow a root program to temporarily drop privileges and be able to
 812  * regain them by swapping the real and effective uid.
 813  */
 814 asmlinkage long sys_setuid(uid_t uid)
 815 {
 816         int old_euid = current->euid;
 817         int old_ruid, old_suid, new_ruid, new_suid;
 818         int retval;
 819
 820         retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
 821         if (retval)
 822                 return retval;
 823
 824         old_ruid = new_ruid = current->uid;
 825         old_suid = current->suid;
 826         new_suid = old_suid;
 827
 828         if (capable(CAP_SETUID)) {
 829                 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
 830                         return -EAGAIN;
 831                 new_suid = uid;
 832         } else if ((uid != current->uid) && (uid != new_suid))
 833                 return -EPERM;
 834
 835         if (old_euid != uid)
 836         {
 837                 current->mm->dumpable = 0;
 838                 wmb();
 839         }
 840         current->fsuid = current->euid = uid;
 841         current->suid = new_suid;
 842
 843         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
 844 }
 845
 846
 847 /*
 848  * This function implements a generic ability to update ruid, euid,
 849  * and suid.  This allows you to implement the 4.4 compatible seteuid().
 850  */
 851 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 852 {
 853         int old_ruid = current->uid;
 854         int old_euid = current->euid;
 855         int old_suid = current->suid;
 856         int retval;
 857
 858         retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
 859         if (retval)
 860                 return retval;
 861
 862         if (!capable(CAP_SETUID)) {
 863                 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
 864                     (ruid != current->euid) && (ruid != current->suid))
 865                         return -EPERM;
 866                 if ((euid != (uid_t) -1) && (euid != current->uid) &&
 867                     (euid != current->euid) && (euid != current->suid))
 868                         return -EPERM;
 869                 if ((suid != (uid_t) -1) && (suid != current->uid) &&
 870                     (suid != current->euid) && (suid != current->suid))
 871                         return -EPERM;
 872         }
 873         if (ruid != (uid_t) -1) {
 874                 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
 875                         return -EAGAIN;
 876         }
 877         if (euid != (uid_t) -1) {
 878                 if (euid != current->euid)
 879                 {
 880                         current->mm->dumpable = 0;
 881                         wmb();
 882                 }
 883                 current->euid = euid;
 884         }
 885         current->fsuid = current->euid;
 886         if (suid != (uid_t) -1)
 887                 current->suid = suid;
 888
 889         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
 890 }
 891
 892 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
 893 {
 894         int retval;
 895
 896         if (!(retval = put_user(current->uid, ruid)) &&
 897             !(retval = put_user(current->euid, euid)))
 898                 retval = put_user(current->suid, suid);
 899
 900         return retval;
 901 }
 902
 903 /*
 904  * Same as above, but for rgid, egid, sgid.
 905  */
 906 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 907 {
 908         int retval;
 909
 910         retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
 911         if (retval)
 912                 return retval;
 913
 914         if (!capable(CAP_SETGID)) {
 915                 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
 916                     (rgid != current->egid) && (rgid != current->sgid))
 917                         return -EPERM;
 918                 if ((egid != (gid_t) -1) && (egid != current->gid) &&
 919                     (egid != current->egid) && (egid != current->sgid))
 920                         return -EPERM;
 921                 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
 922                     (sgid != current->egid) && (sgid != current->sgid))
 923                         return -EPERM;
 924         }
 925         if (egid != (gid_t) -1) {
 926                 if (egid != current->egid)
 927                 {
 928                         current->mm->dumpable = 0;
 929                         wmb();
 930                 }
 931                 current->egid = egid;
 932         }
 933         current->fsgid = current->egid;
 934         if (rgid != (gid_t) -1)
 935                 current->gid = rgid;
 936         if (sgid != (gid_t) -1)
 937                 current->sgid = sgid;
 938         return 0;
 939 }
 940
 941 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
 942 {
 943         int retval;
 944
 945         if (!(retval = put_user(current->gid, rgid)) &&
 946             !(retval = put_user(current->egid, egid)))
 947                 retval = put_user(current->sgid, sgid);
 948
 949         return retval;
 950 }
 951
 952
 953 /*
 954  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 955  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 956  * whatever uid it wants to). It normally shadows "euid", except when
 957  * explicitly set by setfsuid() or for access..
 958  */
 959 asmlinkage long sys_setfsuid(uid_t uid)
 960 {
 961         int old_fsuid;
 962
 963         old_fsuid = current->fsuid;
 964         if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
 965                 return old_fsuid;
 966
 967         if (uid == current->uid || uid == current->euid ||
 968             uid == current->suid || uid == current->fsuid ||
 969             capable(CAP_SETUID))
 970         {
 971                 if (uid != old_fsuid)
 972                 {
 973                         current->mm->dumpable = 0;
 974                         wmb();
 975                 }
 976                 current->fsuid = uid;
 977         }
 978
 979         security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
 980
 981         return old_fsuid;
 982 }
 983
 984 /*
 985  * Samma på svenska..
 986  */
 987 asmlinkage long sys_setfsgid(gid_t gid)
 988 {
 989         int old_fsgid;
 990
 991         old_fsgid = current->fsgid;
 992         if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
 993                 return old_fsgid;
 994
 995         if (gid == current->gid || gid == current->egid ||
 996             gid == current->sgid || gid == current->fsgid ||
 997             capable(CAP_SETGID))
 998         {
 999                 if (gid != old_fsgid)
1000                 {
1001                         current->mm->dumpable = 0;
1002                         wmb();
1003                 }
1004                 current->fsgid = gid;
1005         }
1006         return old_fsgid;
1007 }
1008
1009 asmlinkage long sys_times(struct tms __user * tbuf)
1010 {
1011         /*
1012          *      In the SMP world we might just be unlucky and have one of
1013          *      the times increment as we use it. Since the value is an
1014          *      atomically safe type this is just fine. Conceptually its
1015          *      as if the syscall took an instant longer to occur.
1016          */
1017         if (tbuf) {
1018                 struct tms tmp;
1019                 tmp.tms_utime = jiffies_to_clock_t(current->utime);
1020                 tmp.tms_stime = jiffies_to_clock_t(current->stime);
1021                 tmp.tms_cutime = jiffies_to_clock_t(current->cutime);
1022                 tmp.tms_cstime = jiffies_to_clock_t(current->cstime);
1023                 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1024                         return -EFAULT;
1025         }
1026         return (long) jiffies_64_to_clock_t(get_jiffies_64());
1027 }
1028
1029 /*
1030  * This needs some heavy checking ...
1031  * I just haven't the stomach for it. I also don't fully
1032  * understand sessions/pgrp etc. Let somebody who does explain it.
1033  *
1034  * OK, I think I have the protection semantics right.... this is really
1035  * only important on a multi-user system anyway, to make sure one user
1036  * can't send a signal to a process owned by another.  -TYT, 12/12/91
1037  *
1038  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1039  * LBT 04.03.94
1040  */
1041
1042 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1043 {
1044         struct task_struct *p;
1045         int err = -EINVAL;
1046
1047         if (!pid)
1048                 pid = current->pid;
1049         if (!pgid)
1050                 pgid = pid;
1051         if (pgid < 0)
1052                 return -EINVAL;
1053
1054         /* From this point forward we keep holding onto the tasklist lock
1055          * so that our parent does not change from under us. -DaveM
1056          */
1057         write_lock_irq(&tasklist_lock);
1058
1059         err = -ESRCH;
1060         p = find_task_by_pid(pid);
1061         if (!p)
1062                 goto out;
1063
1064         err = -EINVAL;
1065         if (!thread_group_leader(p))
1066                 goto out;
1067
1068         if (p->parent == current || p->real_parent == current) {
1069                 err = -EPERM;
1070                 if (p->signal->session != current->signal->session)
1071                         goto out;
1072                 err = -EACCES;
1073                 if (p->did_exec)
1074                         goto out;
1075         } else {
1076                 err = -ESRCH;
1077                 if (p != current)
1078                         goto out;
1079         }
1080
1081         err = -EPERM;
1082         if (p->signal->leader)
1083                 goto out;
1084
1085         if (pgid != pid) {
1086                 struct task_struct *p;
1087                 struct pid *pid;
1088                 struct list_head *l;
1089
1090                 for_each_task_pid(pgid, PIDTYPE_PGID, p, l, pid)
1091                         if (p->signal->session == current->signal->session)
1092                                 goto ok_pgid;
1093                 goto out;
1094         }
1095
1096 ok_pgid:
1097         err = security_task_setpgid(p, pgid);
1098         if (err)
1099                 goto out;
1100
1101         if (process_group(p) != pgid) {
1102                 detach_pid(p, PIDTYPE_PGID);
1103                 p->signal->pgrp = pgid;
1104                 attach_pid(p, PIDTYPE_PGID, pgid);
1105         }
1106
1107         err = 0;
1108 out:
1109         /* All paths lead to here, thus we are safe. -DaveM */
1110         write_unlock_irq(&tasklist_lock);
1111         return err;
1112 }
1113
1114 asmlinkage long sys_getpgid(pid_t pid)
1115 {
1116         if (!pid) {
1117                 return process_group(current);
1118         } else {
1119                 int retval;
1120                 struct task_struct *p;
1121
1122                 read_lock(&tasklist_lock);
1123                 p = find_task_by_pid(pid);
1124
1125                 retval = -ESRCH;
1126                 if (p) {
1127                         retval = security_task_getpgid(p);
1128                         if (!retval)
1129                                 retval = process_group(p);
1130                 }
1131                 read_unlock(&tasklist_lock);
1132                 return retval;
1133         }
1134 }
1135
1136 #ifdef __ARCH_WANT_SYS_GETPGRP
1137
1138 asmlinkage long sys_getpgrp(void)
1139 {
1140         /* SMP - assuming writes are word atomic this is fine */
1141         return process_group(current);
1142 }
1143
1144 #endif
1145
1146 asmlinkage long sys_getsid(pid_t pid)
1147 {
1148         if (!pid) {
1149                 return current->signal->session;
1150         } else {
1151                 int retval;
1152                 struct task_struct *p;
1153
1154                 read_lock(&tasklist_lock);
1155                 p = find_task_by_pid(pid);
1156
1157                 retval = -ESRCH;
1158                 if(p) {
1159                         retval = security_task_getsid(p);
1160                         if (!retval)
1161                                 retval = p->signal->session;
1162                 }
1163                 read_unlock(&tasklist_lock);
1164                 return retval;
1165         }
1166 }
1167
1168 asmlinkage long sys_setsid(void)
1169 {
1170         struct pid *pid;
1171         int err = -EPERM;
1172
1173         if (!thread_group_leader(current))
1174                 return -EINVAL;
1175
1176         write_lock_irq(&tasklist_lock);
1177
1178         pid = find_pid(PIDTYPE_PGID, current->pid);
1179         if (pid)
1180                 goto out;
1181
1182         current->signal->leader = 1;
1183         __set_special_pids(current->pid, current->pid);
1184         current->signal->tty = NULL;
1185         current->signal->tty_old_pgrp = 0;
1186         err = process_group(current);
1187 out:
1188         write_unlock_irq(&tasklist_lock);
1189         return err;
1190 }
1191
1192 /*
1193  * Supplementary group IDs
1194  */
1195
1196 /* init to 2 - one for init_task, one to ensure it is never freed */
1197 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1198
1199 struct group_info *groups_alloc(int gidsetsize)
1200 {
1201         struct group_info *group_info;
1202         int nblocks;
1203         int i;
1204
1205         nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1206         /* Make sure we always allocate at least one indirect block pointer */
1207         nblocks = nblocks ? : 1;
1208         group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1209         if (!group_info)
1210                 return NULL;
1211         group_info->ngroups = gidsetsize;
1212         group_info->nblocks = nblocks;
1213         atomic_set(&group_info->usage, 1);
1214
1215         if (gidsetsize <= NGROUPS_SMALL) {
1216                 group_info->blocks[0] = group_info->small_block;
1217         } else {
1218                 for (i = 0; i < nblocks; i++) {
1219                         gid_t *b;
1220                         b = (void *)__get_free_page(GFP_USER);
1221                         if (!b)
1222                                 goto out_undo_partial_alloc;
1223                         group_info->blocks[i] = b;
1224                 }
1225         }
1226         return group_info;
1227
1228 out_undo_partial_alloc:
1229         while (--i >= 0) {
1230                 free_page((unsigned long)group_info->blocks[i]);
1231         }
1232         kfree(group_info);
1233         return NULL;
1234 }
1235
1236 EXPORT_SYMBOL(groups_alloc);
1237
1238 void groups_free(struct group_info *group_info)
1239 {
1240         if (group_info->blocks[0] != group_info->small_block) {
1241                 int i;
1242                 for (i = 0; i < group_info->nblocks; i++)
1243                         free_page((unsigned long)group_info->blocks[i]);
1244         }
1245         kfree(group_info);
1246 }
1247
1248 EXPORT_SYMBOL(groups_free);
1249
1250 /* export the group_info to a user-space array */
1251 static int groups_to_user(gid_t __user *grouplist,
1252     struct group_info *group_info)
1253 {
1254         int i;
1255         int count = group_info->ngroups;
1256
1257         for (i = 0; i < group_info->nblocks; i++) {
1258                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1259                 int off = i * NGROUPS_PER_BLOCK;
1260                 int len = cp_count * sizeof(*grouplist);
1261
1262                 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1263                         return -EFAULT;
1264
1265                 count -= cp_count;
1266         }
1267         return 0;
1268 }
1269
1270 /* fill a group_info from a user-space array - it must be allocated already */
1271 static int groups_from_user(struct group_info *group_info,
1272     gid_t __user *grouplist)
1273  {
1274         int i;
1275         int count = group_info->ngroups;
1276
1277         for (i = 0; i < group_info->nblocks; i++) {
1278                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1279                 int off = i * NGROUPS_PER_BLOCK;
1280                 int len = cp_count * sizeof(*grouplist);
1281
1282                 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1283                         return -EFAULT;
1284
1285                 count -= cp_count;
1286         }
1287         return 0;
1288 }
1289
1290 /* a simple shell-metzner sort */
1291 static void groups_sort(struct group_info *group_info)
1292 {
1293         int base, max, stride;
1294         int gidsetsize = group_info->ngroups;
1295
1296         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1297                 ; /* nothing */
1298         stride /= 3;
1299
1300         while (stride) {
1301                 max = gidsetsize - stride;
1302                 for (base = 0; base < max; base++) {
1303                         int left = base;
1304                         int right = left + stride;
1305                         gid_t tmp = GROUP_AT(group_info, right);
1306
1307                         while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1308                                 GROUP_AT(group_info, right) =
1309                                     GROUP_AT(group_info, left);
1310                                 right = left;
1311                                 left -= stride;
1312                         }
1313                         GROUP_AT(group_info, right) = tmp;
1314                 }
1315                 stride /= 3;
1316         }
1317 }
1318
1319 /* a simple bsearch */
1320 static int groups_search(struct group_info *group_info, gid_t grp)
1321 {
1322         int left, right;
1323
1324         if (!group_info)
1325                 return 0;
1326
1327         left = 0;
1328         right = group_info->ngroups;
1329         while (left < right) {
1330                 int mid = (left+right)/2;
1331                 int cmp = grp - GROUP_AT(group_info, mid);
1332                 if (cmp > 0)
1333                         left = mid + 1;
1334                 else if (cmp < 0)
1335                         right = mid;
1336                 else
1337                         return 1;
1338         }
1339         return 0;
1340 }
1341
1342 /* validate and set current->group_info */
1343 int set_current_groups(struct group_info *group_info)
1344 {
1345         int retval;
1346         struct group_info *old_info;
1347
1348         retval = security_task_setgroups(group_info);
1349         if (retval)
1350                 return retval;
1351
1352         groups_sort(group_info);
1353         get_group_info(group_info);
1354
1355         task_lock(current);
1356         old_info = current->group_info;
1357         current->group_info = group_info;
1358         task_unlock(current);
1359
1360         put_group_info(old_info);
1361
1362         return 0;
1363 }
1364
1365 EXPORT_SYMBOL(set_current_groups);
1366
1367 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1368 {
1369         int i = 0;
1370
1371         /*
1372          *      SMP: Nobody else can change our grouplist. Thus we are
1373          *      safe.
1374          */
1375
1376         if (gidsetsize < 0)
1377                 return -EINVAL;
1378
1379         /* no need to grab task_lock here; it cannot change */
1380         get_group_info(current->group_info);
1381         i = current->group_info->ngroups;
1382         if (gidsetsize) {
1383                 if (i > gidsetsize) {
1384                         i = -EINVAL;
1385                         goto out;
1386                 }
1387                 if (groups_to_user(grouplist, current->group_info)) {
1388                         i = -EFAULT;
1389                         goto out;
1390                 }
1391         }
1392 out:
1393         put_group_info(current->group_info);
1394         return i;
1395 }
1396
1397 /*
1398  *      SMP: Our groups are copy-on-write. We can set them safely
1399  *      without another task interfering.
1400  */
1401
1402 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1403 {
1404         struct group_info *group_info;
1405         int retval;
1406
1407         if (!capable(CAP_SETGID))
1408                 return -EPERM;
1409         if ((unsigned)gidsetsize > NGROUPS_MAX)
1410                 return -EINVAL;
1411
1412         group_info = groups_alloc(gidsetsize);
1413         if (!group_info)
1414                 return -ENOMEM;
1415         retval = groups_from_user(group_info, grouplist);
1416         if (retval) {
1417                 put_group_info(group_info);
1418                 return retval;
1419         }
1420
1421         retval = set_current_groups(group_info);
1422         put_group_info(group_info);
1423
1424         return retval;
1425 }
1426
1427 /*
1428  * Check whether we're fsgid/egid or in the supplemental group..
1429  */
1430 int in_group_p(gid_t grp)
1431 {
1432         int retval = 1;
1433         if (grp != current->fsgid) {
1434                 get_group_info(current->group_info);
1435                 retval = groups_search(current->group_info, grp);
1436                 put_group_info(current->group_info);
1437         }
1438         return retval;
1439 }
1440
1441 EXPORT_SYMBOL(in_group_p);
1442
1443 int in_egroup_p(gid_t grp)
1444 {
1445         int retval = 1;
1446         if (grp != current->egid) {
1447                 get_group_info(current->group_info);
1448                 retval = groups_search(current->group_info, grp);
1449                 put_group_info(current->group_info);
1450         }
1451         return retval;
1452 }
1453
1454 EXPORT_SYMBOL(in_egroup_p);
1455
1456 DECLARE_RWSEM(uts_sem);
1457
1458 EXPORT_SYMBOL(uts_sem);
1459
1460 asmlinkage long sys_newuname(struct new_utsname __user * name)
1461 {
1462         int errno = 0;
1463
1464         down_read(&uts_sem);
1465         if (copy_to_user(name, vx_new_utsname(), sizeof *name))
1466                 errno = -EFAULT;
1467         up_read(&uts_sem);
1468         return errno;
1469 }
1470
1471 asmlinkage long sys_sethostname(char __user *name, int len)
1472 {
1473         int errno;
1474         char tmp[__NEW_UTS_LEN];
1475
1476         if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SET_UTSNAME))
1477                 return -EPERM;
1478         if (len < 0 || len > __NEW_UTS_LEN)
1479                 return -EINVAL;
1480         down_write(&uts_sem);
1481         errno = -EFAULT;
1482         if (!copy_from_user(tmp, name, len)) {
1483                 char *ptr = vx_new_uts(nodename);
1484
1485                 memcpy(ptr, tmp, len);
1486                 ptr[len] = 0;
1487                 errno = 0;
1488         }
1489         up_write(&uts_sem);
1490         return errno;
1491 }
1492
1493 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1494
1495 asmlinkage long sys_gethostname(char __user *name, int len)
1496 {
1497         int i, errno;
1498         char *ptr;
1499
1500         if (len < 0)
1501                 return -EINVAL;
1502         down_read(&uts_sem);
1503         ptr = vx_new_uts(nodename);
1504         i = 1 + strlen(ptr);
1505         if (i > len)
1506                 i = len;
1507         errno = 0;
1508         if (copy_to_user(name, ptr, i))
1509                 errno = -EFAULT;
1510         up_read(&uts_sem);
1511         return errno;
1512 }
1513
1514 #endif
1515
1516 /*
1517  * Only setdomainname; getdomainname can be implemented by calling
1518  * uname()
1519  */
1520 asmlinkage long sys_setdomainname(char __user *name, int len)
1521 {
1522         int errno;
1523         char tmp[__NEW_UTS_LEN];
1524
1525         if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SET_UTSNAME))
1526                 return -EPERM;
1527         if (len < 0 || len > __NEW_UTS_LEN)
1528                 return -EINVAL;
1529
1530         down_write(&uts_sem);
1531         errno = -EFAULT;
1532         if (!copy_from_user(tmp, name, len)) {
1533                 char *ptr = vx_new_uts(domainname);
1534
1535                 memcpy(ptr, tmp, len);
1536                 ptr[len] = 0;
1537                 errno = 0;
1538         }
1539         up_write(&uts_sem);
1540         return errno;
1541 }
1542
1543 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1544 {
1545         if (resource >= RLIM_NLIMITS)
1546                 return -EINVAL;
1547         else
1548                 return copy_to_user(rlim, current->rlim + resource, sizeof(*rlim))
1549                         ? -EFAULT : 0;
1550 }
1551
1552 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1553
1554 /*
1555  *      Back compatibility for getrlimit. Needed for some apps.
1556  */
1557
1558 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1559 {
1560         struct rlimit x;
1561         if (resource >= RLIM_NLIMITS)
1562                 return -EINVAL;
1563
1564         memcpy(&x, current->rlim + resource, sizeof(*rlim));
1565         if(x.rlim_cur > 0x7FFFFFFF)
1566                 x.rlim_cur = 0x7FFFFFFF;
1567         if(x.rlim_max > 0x7FFFFFFF)
1568                 x.rlim_max = 0x7FFFFFFF;
1569         return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1570 }
1571
1572 #endif
1573
1574 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1575 {
1576         struct rlimit new_rlim, *old_rlim;
1577         int retval;
1578
1579         if (resource >= RLIM_NLIMITS)
1580                 return -EINVAL;
1581         if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1582                 return -EFAULT;
1583        if (new_rlim.rlim_cur > new_rlim.rlim_max)
1584                return -EINVAL;
1585         old_rlim = current->rlim + resource;
1586         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
1587              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
1588             !capable(CAP_SYS_RESOURCE) && vx_ccaps(VXC_SET_RLIMIT))
1589                 return -EPERM;
1590         if (resource == RLIMIT_NOFILE) {
1591                 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
1592                         return -EPERM;
1593         }
1594
1595         retval = security_task_setrlimit(resource, &new_rlim);
1596         if (retval)
1597                 return retval;
1598
1599         *old_rlim = new_rlim;
1600         return 0;
1601 }
1602
1603 /*
1604  * It would make sense to put struct rusage in the task_struct,
1605  * except that would make the task_struct be *really big*.  After
1606  * task_struct gets moved into malloc'ed memory, it would
1607  * make sense to do this.  It will make moving the rest of the information
1608  * a lot simpler!  (Which we're not doing right now because we're not
1609  * measuring them yet).
1610  *
1611  * This is SMP safe.  Either we are called from sys_getrusage on ourselves
1612  * below (we know we aren't going to exit/disappear and only we change our
1613  * rusage counters), or we are called from wait4() on a process which is
1614  * either stopped or zombied.  In the zombied case the task won't get
1615  * reaped till shortly after the call to getrusage(), in both cases the
1616  * task being examined is in a frozen state so the counters won't change.
1617  */
1618 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1619 {
1620         struct rusage r;
1621
1622         memset((char *) &r, 0, sizeof(r));
1623         switch (who) {
1624                 case RUSAGE_SELF:
1625                         jiffies_to_timeval(p->utime, &r.ru_utime);
1626                         jiffies_to_timeval(p->stime, &r.ru_stime);
1627                         r.ru_nvcsw = p->nvcsw;
1628                         r.ru_nivcsw = p->nivcsw;
1629                         r.ru_minflt = p->min_flt;
1630                         r.ru_majflt = p->maj_flt;
1631                         break;
1632                 case RUSAGE_CHILDREN:
1633                         jiffies_to_timeval(p->cutime, &r.ru_utime);
1634                         jiffies_to_timeval(p->cstime, &r.ru_stime);
1635                         r.ru_nvcsw = p->cnvcsw;
1636                         r.ru_nivcsw = p->cnivcsw;
1637                         r.ru_minflt = p->cmin_flt;
1638                         r.ru_majflt = p->cmaj_flt;
1639                         break;
1640                 default:
1641                         jiffies_to_timeval(p->utime + p->cutime, &r.ru_utime);
1642                         jiffies_to_timeval(p->stime + p->cstime, &r.ru_stime);
1643                         r.ru_nvcsw = p->nvcsw + p->cnvcsw;
1644                         r.ru_nivcsw = p->nivcsw + p->cnivcsw;
1645                         r.ru_minflt = p->min_flt + p->cmin_flt;
1646                         r.ru_majflt = p->maj_flt + p->cmaj_flt;
1647                         break;
1648         }
1649         return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1650 }
1651
1652 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1653 {
1654         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1655                 return -EINVAL;
1656         return getrusage(current, who, ru);
1657 }
1658
1659 asmlinkage long sys_umask(int mask)
1660 {
1661         mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1662         return mask;
1663 }
1664
1665 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1666                           unsigned long arg4, unsigned long arg5)
1667 {
1668         int error;
1669         int sig;
1670
1671         error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1672         if (error)
1673                 return error;
1674
1675         switch (option) {
1676                 case PR_SET_PDEATHSIG:
1677                         sig = arg2;
1678                         if (sig < 0 || sig > _NSIG) {
1679                                 error = -EINVAL;
1680                                 break;
1681                         }
1682                         current->pdeath_signal = sig;
1683                         break;
1684                 case PR_GET_PDEATHSIG:
1685                         error = put_user(current->pdeath_signal, (int __user *)arg2);
1686                         break;
1687                 case PR_GET_DUMPABLE:
1688                         if (current->mm->dumpable)
1689                                 error = 1;
1690                         break;
1691                 case PR_SET_DUMPABLE:
1692                         if (arg2 != 0 && arg2 != 1) {
1693                                 error = -EINVAL;
1694                                 break;
1695                         }
1696                         current->mm->dumpable = arg2;
1697                         break;
1698
1699                 case PR_SET_UNALIGN:
1700                         error = SET_UNALIGN_CTL(current, arg2);
1701                         break;
1702                 case PR_GET_UNALIGN:
1703                         error = GET_UNALIGN_CTL(current, arg2);
1704                         break;
1705                 case PR_SET_FPEMU:
1706                         error = SET_FPEMU_CTL(current, arg2);
1707                         break;
1708                 case PR_GET_FPEMU:
1709                         error = GET_FPEMU_CTL(current, arg2);
1710                         break;
1711                 case PR_SET_FPEXC:
1712                         error = SET_FPEXC_CTL(current, arg2);
1713                         break;
1714                 case PR_GET_FPEXC:
1715                         error = GET_FPEXC_CTL(current, arg2);
1716                         break;
1717                 case PR_GET_TIMING:
1718                         error = PR_TIMING_STATISTICAL;
1719                         break;
1720                 case PR_SET_TIMING:
1721                         if (arg2 == PR_TIMING_STATISTICAL)
1722                                 error = 0;
1723                         else
1724                                 error = -EINVAL;
1725                         break;
1726
1727                 case PR_GET_KEEPCAPS:
1728                         if (current->keep_capabilities)
1729                                 error = 1;
1730                         break;
1731                 case PR_SET_KEEPCAPS:
1732                         if (arg2 != 0 && arg2 != 1) {
1733                                 error = -EINVAL;
1734                                 break;
1735                         }
1736                         current->keep_capabilities = arg2;
1737                         break;
1738                 default:
1739                         error = -EINVAL;
1740                         break;
1741         }
1742         return error;
1743 }