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
 276 /* arch-specific weak syscall entries */
 277 cond_syscall(sys_pciconfig_read)
 278 cond_syscall(sys_pciconfig_write)
 279 cond_syscall(sys_pciconfig_iobase)
 280
 281 static int set_one_prio(struct task_struct *p, int niceval, int error)
 282 {
 283         int no_nice;
 284
 285         if (p->uid != current->euid &&
 286                 p->uid != current->uid && !capable(CAP_SYS_NICE)) {
 287                 error = -EPERM;
 288                 goto out;
 289         }
 290         if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) {
 291                 error = -EACCES;
 292                 goto out;
 293         }
 294         no_nice = security_task_setnice(p, niceval);
 295         if (no_nice) {
 296                 error = no_nice;
 297                 goto out;
 298         }
 299         if (error == -ESRCH)
 300                 error = 0;
 301         set_user_nice(p, niceval);
 302 out:
 303         return error;
 304 }
 305
 306 asmlinkage long sys_setpriority(int which, int who, int niceval)
 307 {
 308         struct task_struct *g, *p;
 309         struct user_struct *user;
 310         struct pid *pid;
 311         struct list_head *l;
 312         int error = -EINVAL;
 313
 314         if (which > 2 || which < 0)
 315                 goto out;
 316
 317         /* normalize: avoid signed division (rounding problems) */
 318         error = -ESRCH;
 319         if (niceval < -20)
 320                 niceval = -20;
 321         if (niceval > 19)
 322                 niceval = 19;
 323
 324         read_lock(&tasklist_lock);
 325         switch (which) {
 326                 case PRIO_PROCESS:
 327                         if (!who)
 328                                 who = current->pid;
 329                         p = find_task_by_pid(who);
 330                         if (p)
 331                                 error = set_one_prio(p, niceval, error);
 332                         break;
 333                 case PRIO_PGRP:
 334                         if (!who)
 335                                 who = process_group(current);
 336                         for_each_task_pid(who, PIDTYPE_PGID, p, l, pid)
 337                                 error = set_one_prio(p, niceval, error);
 338                         break;
 339                 case PRIO_USER:
 340                         if (!who)
 341                                 user = current->user;
 342                         else
 343                                 user = find_user(vx_current_xid(), who);
 344
 345                         if (!user)
 346                                 goto out_unlock;
 347
 348                         do_each_thread(g, p)
 349                                 if (p->uid == who)
 350                                         error = set_one_prio(p, niceval, error);
 351                         while_each_thread(g, p);
 352                         break;
 353         }
 354 out_unlock:
 355         read_unlock(&tasklist_lock);
 356 out:
 357         return error;
 358 }
 359
 360 /*
 361  * Ugh. To avoid negative return values, "getpriority()" will
 362  * not return the normal nice-value, but a negated value that
 363  * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 364  * to stay compatible.
 365  */
 366 asmlinkage long sys_getpriority(int which, int who)
 367 {
 368         struct task_struct *g, *p;
 369         struct list_head *l;
 370         struct pid *pid;
 371         struct user_struct *user;
 372         long niceval, retval = -ESRCH;
 373
 374         if (which > 2 || which < 0)
 375                 return -EINVAL;
 376
 377         read_lock(&tasklist_lock);
 378         switch (which) {
 379                 case PRIO_PROCESS:
 380                         if (!who)
 381                                 who = current->pid;
 382                         p = find_task_by_pid(who);
 383                         if (p) {
 384                                 niceval = 20 - task_nice(p);
 385                                 if (niceval > retval)
 386                                         retval = niceval;
 387                         }
 388                         break;
 389                 case PRIO_PGRP:
 390                         if (!who)
 391                                 who = process_group(current);
 392                         for_each_task_pid(who, PIDTYPE_PGID, p, l, pid) {
 393                                 niceval = 20 - task_nice(p);
 394                                 if (niceval > retval)
 395                                         retval = niceval;
 396                         }
 397                         break;
 398                 case PRIO_USER:
 399                         if (!who)
 400                                 user = current->user;
 401                         else
 402                                 user = find_user(vx_current_xid(), who);
 403
 404                         if (!user)
 405                                 goto out_unlock;
 406
 407                         do_each_thread(g, p)
 408                                 if (p->uid == who) {
 409                                         niceval = 20 - task_nice(p);
 410                                         if (niceval > retval)
 411                                                 retval = niceval;
 412                                 }
 413                         while_each_thread(g, p);
 414                         break;
 415         }
 416 out_unlock:
 417         read_unlock(&tasklist_lock);
 418
 419         return retval;
 420 }
 421
 422 /*
 423  *      vshelper path is set via /proc/sys
 424  *      invoked by vserver sys_reboot(), with
 425  *      the following arguments
 426  *
 427  *      argv [0] = vshelper_path;
 428  *      argv [1] = action: "restart", "halt", "poweroff", ...
 429  *      argv [2] = context identifier
 430  *      argv [3] = additional argument (restart2)
 431  *
 432  *      envp [*] = type-specific parameters
 433  */
 434 char vshelper_path[255] = "/sbin/vshelper";
 435
 436 long vs_reboot(unsigned int cmd, void * arg)
 437 {
 438         char id_buf[8], cmd_buf[32];
 439         char uid_buf[32], pid_buf[32];
 440         char buffer[256];
 441
 442         char *argv[] = {vshelper_path, NULL, id_buf, NULL, 0};
 443         char *envp[] = {"HOME=/", "TERM=linux",
 444                         "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 445                         uid_buf, pid_buf, cmd_buf, 0};
 446
 447         snprintf(id_buf, sizeof(id_buf)-1, "%d", vx_current_xid());
 448
 449         snprintf(cmd_buf, sizeof(cmd_buf)-1, "VS_CMD=%08x", cmd);
 450         snprintf(uid_buf, sizeof(uid_buf)-1, "VS_UID=%d", current->uid);
 451         snprintf(pid_buf, sizeof(pid_buf)-1, "VS_PID=%d", current->pid);
 452
 453         switch (cmd) {
 454         case LINUX_REBOOT_CMD_RESTART:
 455                 argv[1] = "restart";
 456                 break;
 457
 458         case LINUX_REBOOT_CMD_HALT:
 459                 argv[1] = "halt";
 460                 break;
 461
 462         case LINUX_REBOOT_CMD_POWER_OFF:
 463                 argv[1] = "poweroff";
 464                 break;
 465
 466         case LINUX_REBOOT_CMD_SW_SUSPEND:
 467                 argv[1] = "swsusp";
 468                 break;
 469
 470         case LINUX_REBOOT_CMD_RESTART2:
 471                 if (strncpy_from_user(&buffer[0], (char *)arg, sizeof(buffer) - 1) < 0)
 472                         return -EFAULT;
 473                 argv[3] = buffer;
 474         default:
 475                 argv[1] = "restart2";
 476                 break;
 477         }
 478
 479         /* maybe we should wait ? */
 480         if (call_usermodehelper(*argv, argv, envp, 0)) {
 481                 printk( KERN_WARNING
 482                         "vs_reboot(): failed to exec (%s %s %s %s)\n",
 483                         vshelper_path, argv[1], argv[2], argv[3]);
 484                 return -EPERM;
 485         }
 486         return 0;
 487 }
 488
 489 /*
 490  * Reboot system call: for obvious reasons only root may call it,
 491  * and even root needs to set up some magic numbers in the registers
 492  * so that some mistake won't make this reboot the whole machine.
 493  * You can also set the meaning of the ctrl-alt-del-key here.
 494  *
 495  * reboot doesn't sync: do that yourself before calling this.
 496  */
 497 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
 498 {
 499         char buffer[256];
 500
 501         /* We only trust the superuser with rebooting the system. */
 502         if (!capable(CAP_SYS_BOOT))
 503                 return -EPERM;
 504
 505         /* For safety, we require "magic" arguments. */
 506         if (magic1 != LINUX_REBOOT_MAGIC1 ||
 507             (magic2 != LINUX_REBOOT_MAGIC2 &&
 508                         magic2 != LINUX_REBOOT_MAGIC2A &&
 509                         magic2 != LINUX_REBOOT_MAGIC2B &&
 510                         magic2 != LINUX_REBOOT_MAGIC2C))
 511                 return -EINVAL;
 512
 513         if (!vx_check(0, VX_ADMIN|VX_WATCH))
 514                 return vs_reboot(cmd, arg);
 515
 516         lock_kernel();
 517         switch (cmd) {
 518         case LINUX_REBOOT_CMD_RESTART:
 519                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 520                 system_state = SYSTEM_SHUTDOWN;
 521                 device_shutdown();
 522                 printk(KERN_EMERG "Restarting system.\n");
 523                 machine_restart(NULL);
 524                 break;
 525
 526         case LINUX_REBOOT_CMD_CAD_ON:
 527                 C_A_D = 1;
 528                 break;
 529
 530         case LINUX_REBOOT_CMD_CAD_OFF:
 531                 C_A_D = 0;
 532                 break;
 533
 534         case LINUX_REBOOT_CMD_HALT:
 535                 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
 536                 system_state = SYSTEM_SHUTDOWN;
 537                 device_shutdown();
 538                 printk(KERN_EMERG "System halted.\n");
 539                 machine_halt();
 540                 unlock_kernel();
 541                 do_exit(0);
 542                 break;
 543
 544         case LINUX_REBOOT_CMD_POWER_OFF:
 545                 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
 546                 system_state = SYSTEM_SHUTDOWN;
 547                 device_shutdown();
 548                 printk(KERN_EMERG "Power down.\n");
 549                 machine_power_off();
 550                 unlock_kernel();
 551                 do_exit(0);
 552                 break;
 553
 554         case LINUX_REBOOT_CMD_RESTART2:
 555                 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
 556                         unlock_kernel();
 557                         return -EFAULT;
 558                 }
 559                 buffer[sizeof(buffer) - 1] = '\0';
 560
 561                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
 562                 system_state = SYSTEM_SHUTDOWN;
 563                 device_shutdown();
 564                 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
 565                 machine_restart(buffer);
 566                 break;
 567
 568 #ifdef CONFIG_SOFTWARE_SUSPEND
 569         case LINUX_REBOOT_CMD_SW_SUSPEND:
 570                 {
 571                         int ret = software_suspend();
 572                         unlock_kernel();
 573                         return ret;
 574                 }
 575 #endif
 576
 577         default:
 578                 unlock_kernel();
 579                 return -EINVAL;
 580         }
 581         unlock_kernel();
 582         return 0;
 583 }
 584
 585 static void deferred_cad(void *dummy)
 586 {
 587         notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 588         machine_restart(NULL);
 589 }
 590
 591 /*
 592  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 593  * As it's called within an interrupt, it may NOT sync: the only choice
 594  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 595  */
 596 void ctrl_alt_del(void)
 597 {
 598         static DECLARE_WORK(cad_work, deferred_cad, NULL);
 599
 600         if (C_A_D)
 601                 schedule_work(&cad_work);
 602         else
 603                 kill_proc(cad_pid, SIGINT, 1);
 604 }
 605
 606
 607 /*
 608  * Unprivileged users may change the real gid to the effective gid
 609  * or vice versa.  (BSD-style)
 610  *
 611  * If you set the real gid at all, or set the effective gid to a value not
 612  * equal to the real gid, then the saved gid is set to the new effective gid.
 613  *
 614  * This makes it possible for a setgid program to completely drop its
 615  * privileges, which is often a useful assertion to make when you are doing
 616  * a security audit over a program.
 617  *
 618  * The general idea is that a program which uses just setregid() will be
 619  * 100% compatible with BSD.  A program which uses just setgid() will be
 620  * 100% compatible with POSIX with saved IDs.
 621  *
 622  * SMP: There are not races, the GIDs are checked only by filesystem
 623  *      operations (as far as semantic preservation is concerned).
 624  */
 625 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
 626 {
 627         int old_rgid = current->gid;
 628         int old_egid = current->egid;
 629         int new_rgid = old_rgid;
 630         int new_egid = old_egid;
 631         int retval;
 632
 633         retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
 634         if (retval)
 635                 return retval;
 636
 637         if (rgid != (gid_t) -1) {
 638                 if ((old_rgid == rgid) ||
 639                     (current->egid==rgid) ||
 640                     capable(CAP_SETGID))
 641                         new_rgid = rgid;
 642                 else
 643                         return -EPERM;
 644         }
 645         if (egid != (gid_t) -1) {
 646                 if ((old_rgid == egid) ||
 647                     (current->egid == egid) ||
 648                     (current->sgid == egid) ||
 649                     capable(CAP_SETGID))
 650                         new_egid = egid;
 651                 else {
 652                         return -EPERM;
 653                 }
 654         }
 655         if (new_egid != old_egid)
 656         {
 657                 current->mm->dumpable = 0;
 658                 wmb();
 659         }
 660         if (rgid != (gid_t) -1 ||
 661             (egid != (gid_t) -1 && egid != old_rgid))
 662                 current->sgid = new_egid;
 663         current->fsgid = new_egid;
 664         current->egid = new_egid;
 665         current->gid = new_rgid;
 666         return 0;
 667 }
 668
 669 /*
 670  * setgid() is implemented like SysV w/ SAVED_IDS
 671  *
 672  * SMP: Same implicit races as above.
 673  */
 674 asmlinkage long sys_setgid(gid_t gid)
 675 {
 676         int old_egid = current->egid;
 677         int retval;
 678
 679         retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
 680         if (retval)
 681                 return retval;
 682
 683         if (capable(CAP_SETGID))
 684         {
 685                 if(old_egid != gid)
 686                 {
 687                         current->mm->dumpable=0;
 688                         wmb();
 689                 }
 690                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 691         }
 692         else if ((gid == current->gid) || (gid == current->sgid))
 693         {
 694                 if(old_egid != gid)
 695                 {
 696                         current->mm->dumpable=0;
 697                         wmb();
 698                 }
 699                 current->egid = current->fsgid = gid;
 700         }
 701         else
 702                 return -EPERM;
 703         return 0;
 704 }
 705
 706 static int set_user(uid_t new_ruid, int dumpclear)
 707 {
 708         struct user_struct *new_user;
 709
 710         new_user = alloc_uid(vx_current_xid(), new_ruid);
 711         if (!new_user)
 712                 return -EAGAIN;
 713
 714         if (atomic_read(&new_user->processes) >=
 715                                 current->rlim[RLIMIT_NPROC].rlim_cur &&
 716                         new_user != &root_user) {
 717                 free_uid(new_user);
 718                 return -EAGAIN;
 719         }
 720
 721         switch_uid(new_user);
 722
 723         if(dumpclear)
 724         {
 725                 current->mm->dumpable = 0;
 726                 wmb();
 727         }
 728         current->uid = new_ruid;
 729         return 0;
 730 }
 731
 732 /*
 733  * Unprivileged users may change the real uid to the effective uid
 734  * or vice versa.  (BSD-style)
 735  *
 736  * If you set the real uid at all, or set the effective uid to a value not
 737  * equal to the real uid, then the saved uid is set to the new effective uid.
 738  *
 739  * This makes it possible for a setuid program to completely drop its
 740  * privileges, which is often a useful assertion to make when you are doing
 741  * a security audit over a program.
 742  *
 743  * The general idea is that a program which uses just setreuid() will be
 744  * 100% compatible with BSD.  A program which uses just setuid() will be
 745  * 100% compatible with POSIX with saved IDs.
 746  */
 747 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
 748 {
 749         int old_ruid, old_euid, old_suid, new_ruid, new_euid;
 750         int retval;
 751
 752         retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
 753         if (retval)
 754                 return retval;
 755
 756         new_ruid = old_ruid = current->uid;
 757         new_euid = old_euid = current->euid;
 758         old_suid = current->suid;
 759
 760         if (ruid != (uid_t) -1) {
 761                 new_ruid = ruid;
 762                 if ((old_ruid != ruid) &&
 763                     (current->euid != ruid) &&
 764                     !capable(CAP_SETUID))
 765                         return -EPERM;
 766         }
 767
 768         if (euid != (uid_t) -1) {
 769                 new_euid = euid;
 770                 if ((old_ruid != euid) &&
 771                     (current->euid != euid) &&
 772                     (current->suid != euid) &&
 773                     !capable(CAP_SETUID))
 774                         return -EPERM;
 775         }
 776
 777         if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
 778                 return -EAGAIN;
 779
 780         if (new_euid != old_euid)
 781         {
 782                 current->mm->dumpable=0;
 783                 wmb();
 784         }
 785         current->fsuid = current->euid = new_euid;
 786         if (ruid != (uid_t) -1 ||
 787             (euid != (uid_t) -1 && euid != old_ruid))
 788                 current->suid = current->euid;
 789         current->fsuid = current->euid;
 790
 791         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
 792 }
 793
 794
 795
 796 /*
 797  * setuid() is implemented like SysV with SAVED_IDS
 798  *
 799  * Note that SAVED_ID's is deficient in that a setuid root program
 800  * like sendmail, for example, cannot set its uid to be a normal
 801  * user and then switch back, because if you're root, setuid() sets
 802  * the saved uid too.  If you don't like this, blame the bright people
 803  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 804  * will allow a root program to temporarily drop privileges and be able to
 805  * regain them by swapping the real and effective uid.
 806  */
 807 asmlinkage long sys_setuid(uid_t uid)
 808 {
 809         int old_euid = current->euid;
 810         int old_ruid, old_suid, new_ruid, new_suid;
 811         int retval;
 812
 813         retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
 814         if (retval)
 815                 return retval;
 816
 817         old_ruid = new_ruid = current->uid;
 818         old_suid = current->suid;
 819         new_suid = old_suid;
 820
 821         if (capable(CAP_SETUID)) {
 822                 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
 823                         return -EAGAIN;
 824                 new_suid = uid;
 825         } else if ((uid != current->uid) && (uid != new_suid))
 826                 return -EPERM;
 827
 828         if (old_euid != uid)
 829         {
 830                 current->mm->dumpable = 0;
 831                 wmb();
 832         }
 833         current->fsuid = current->euid = uid;
 834         current->suid = new_suid;
 835
 836         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
 837 }
 838
 839
 840 /*
 841  * This function implements a generic ability to update ruid, euid,
 842  * and suid.  This allows you to implement the 4.4 compatible seteuid().
 843  */
 844 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 845 {
 846         int old_ruid = current->uid;
 847         int old_euid = current->euid;
 848         int old_suid = current->suid;
 849         int retval;
 850
 851         retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
 852         if (retval)
 853                 return retval;
 854
 855         if (!capable(CAP_SETUID)) {
 856                 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
 857                     (ruid != current->euid) && (ruid != current->suid))
 858                         return -EPERM;
 859                 if ((euid != (uid_t) -1) && (euid != current->uid) &&
 860                     (euid != current->euid) && (euid != current->suid))
 861                         return -EPERM;
 862                 if ((suid != (uid_t) -1) && (suid != current->uid) &&
 863                     (suid != current->euid) && (suid != current->suid))
 864                         return -EPERM;
 865         }
 866         if (ruid != (uid_t) -1) {
 867                 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
 868                         return -EAGAIN;
 869         }
 870         if (euid != (uid_t) -1) {
 871                 if (euid != current->euid)
 872                 {
 873                         current->mm->dumpable = 0;
 874                         wmb();
 875                 }
 876                 current->euid = euid;
 877         }
 878         current->fsuid = current->euid;
 879         if (suid != (uid_t) -1)
 880                 current->suid = suid;
 881
 882         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
 883 }
 884
 885 asmlinkage long sys_getresuid(uid_t *ruid, uid_t *euid, uid_t *suid)
 886 {
 887         int retval;
 888
 889         if (!(retval = put_user(current->uid, ruid)) &&
 890             !(retval = put_user(current->euid, euid)))
 891                 retval = put_user(current->suid, suid);
 892
 893         return retval;
 894 }
 895
 896 /*
 897  * Same as above, but for rgid, egid, sgid.
 898  */
 899 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 900 {
 901         int retval;
 902
 903         retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
 904         if (retval)
 905                 return retval;
 906
 907         if (!capable(CAP_SETGID)) {
 908                 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
 909                     (rgid != current->egid) && (rgid != current->sgid))
 910                         return -EPERM;
 911                 if ((egid != (gid_t) -1) && (egid != current->gid) &&
 912                     (egid != current->egid) && (egid != current->sgid))
 913                         return -EPERM;
 914                 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
 915                     (sgid != current->egid) && (sgid != current->sgid))
 916                         return -EPERM;
 917         }
 918         if (egid != (gid_t) -1) {
 919                 if (egid != current->egid)
 920                 {
 921                         current->mm->dumpable = 0;
 922                         wmb();
 923                 }
 924                 current->egid = egid;
 925         }
 926         current->fsgid = current->egid;
 927         if (rgid != (gid_t) -1)
 928                 current->gid = rgid;
 929         if (sgid != (gid_t) -1)
 930                 current->sgid = sgid;
 931         return 0;
 932 }
 933
 934 asmlinkage long sys_getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid)
 935 {
 936         int retval;
 937
 938         if (!(retval = put_user(current->gid, rgid)) &&
 939             !(retval = put_user(current->egid, egid)))
 940                 retval = put_user(current->sgid, sgid);
 941
 942         return retval;
 943 }
 944
 945
 946 /*
 947  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 948  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 949  * whatever uid it wants to). It normally shadows "euid", except when
 950  * explicitly set by setfsuid() or for access..
 951  */
 952 asmlinkage long sys_setfsuid(uid_t uid)
 953 {
 954         int old_fsuid;
 955
 956         old_fsuid = current->fsuid;
 957         if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
 958                 return old_fsuid;
 959
 960         if (uid == current->uid || uid == current->euid ||
 961             uid == current->suid || uid == current->fsuid ||
 962             capable(CAP_SETUID))
 963         {
 964                 if (uid != old_fsuid)
 965                 {
 966                         current->mm->dumpable = 0;
 967                         wmb();
 968                 }
 969                 current->fsuid = uid;
 970         }
 971
 972         security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
 973
 974         return old_fsuid;
 975 }
 976
 977 /*
 978  * Samma på svenska..
 979  */
 980 asmlinkage long sys_setfsgid(gid_t gid)
 981 {
 982         int old_fsgid;
 983
 984         old_fsgid = current->fsgid;
 985         if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
 986                 return old_fsgid;
 987
 988         if (gid == current->gid || gid == current->egid ||
 989             gid == current->sgid || gid == current->fsgid ||
 990             capable(CAP_SETGID))
 991         {
 992                 if (gid != old_fsgid)
 993                 {
 994                         current->mm->dumpable = 0;
 995                         wmb();
 996                 }
 997                 current->fsgid = gid;
 998         }
 999         return old_fsgid;
1000 }
1001
1002 asmlinkage long sys_times(struct tms __user * tbuf)
1003 {
1004         /*
1005          *      In the SMP world we might just be unlucky and have one of
1006          *      the times increment as we use it. Since the value is an
1007          *      atomically safe type this is just fine. Conceptually its
1008          *      as if the syscall took an instant longer to occur.
1009          */
1010         if (tbuf) {
1011                 struct tms tmp;
1012                 tmp.tms_utime = jiffies_to_clock_t(current->utime);
1013                 tmp.tms_stime = jiffies_to_clock_t(current->stime);
1014                 tmp.tms_cutime = jiffies_to_clock_t(current->cutime);
1015                 tmp.tms_cstime = jiffies_to_clock_t(current->cstime);
1016                 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1017                         return -EFAULT;
1018         }
1019         return (long) jiffies_64_to_clock_t(get_jiffies_64());
1020 }
1021
1022 /*
1023  * This needs some heavy checking ...
1024  * I just haven't the stomach for it. I also don't fully
1025  * understand sessions/pgrp etc. Let somebody who does explain it.
1026  *
1027  * OK, I think I have the protection semantics right.... this is really
1028  * only important on a multi-user system anyway, to make sure one user
1029  * can't send a signal to a process owned by another.  -TYT, 12/12/91
1030  *
1031  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1032  * LBT 04.03.94
1033  */
1034
1035 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1036 {
1037         struct task_struct *p;
1038         int err = -EINVAL;
1039
1040         if (!pid)
1041                 pid = current->pid;
1042         if (!pgid)
1043                 pgid = pid;
1044         if (pgid < 0)
1045                 return -EINVAL;
1046
1047         /* From this point forward we keep holding onto the tasklist lock
1048          * so that our parent does not change from under us. -DaveM
1049          */
1050         write_lock_irq(&tasklist_lock);
1051
1052         err = -ESRCH;
1053         p = find_task_by_pid(pid);
1054         if (!p)
1055                 goto out;
1056
1057         err = -EINVAL;
1058         if (!thread_group_leader(p))
1059                 goto out;
1060
1061         if (p->parent == current || p->real_parent == current) {
1062                 err = -EPERM;
1063                 if (p->signal->session != current->signal->session)
1064                         goto out;
1065                 err = -EACCES;
1066                 if (p->did_exec)
1067                         goto out;
1068         } else {
1069                 err = -ESRCH;
1070                 if (p != current)
1071                         goto out;
1072         }
1073
1074         err = -EPERM;
1075         if (p->signal->leader)
1076                 goto out;
1077
1078         if (pgid != pid) {
1079                 struct task_struct *p;
1080                 struct pid *pid;
1081                 struct list_head *l;
1082
1083                 for_each_task_pid(pgid, PIDTYPE_PGID, p, l, pid)
1084                         if (p->signal->session == current->signal->session)
1085                                 goto ok_pgid;
1086                 goto out;
1087         }
1088
1089 ok_pgid:
1090         err = security_task_setpgid(p, pgid);
1091         if (err)
1092                 goto out;
1093
1094         if (process_group(p) != pgid) {
1095                 detach_pid(p, PIDTYPE_PGID);
1096                 p->signal->pgrp = pgid;
1097                 attach_pid(p, PIDTYPE_PGID, pgid);
1098         }
1099
1100         err = 0;
1101 out:
1102         /* All paths lead to here, thus we are safe. -DaveM */
1103         write_unlock_irq(&tasklist_lock);
1104         return err;
1105 }
1106
1107 asmlinkage long sys_getpgid(pid_t pid)
1108 {
1109         if (!pid) {
1110                 return process_group(current);
1111         } else {
1112                 int retval;
1113                 struct task_struct *p;
1114
1115                 read_lock(&tasklist_lock);
1116                 p = find_task_by_pid(pid);
1117
1118                 retval = -ESRCH;
1119                 if (p) {
1120                         retval = security_task_getpgid(p);
1121                         if (!retval)
1122                                 retval = process_group(p);
1123                 }
1124                 read_unlock(&tasklist_lock);
1125                 return retval;
1126         }
1127 }
1128
1129 asmlinkage long sys_getpgrp(void)
1130 {
1131         /* SMP - assuming writes are word atomic this is fine */
1132         return process_group(current);
1133 }
1134
1135 asmlinkage long sys_getsid(pid_t pid)
1136 {
1137         if (!pid) {
1138                 return current->signal->session;
1139         } else {
1140                 int retval;
1141                 struct task_struct *p;
1142
1143                 read_lock(&tasklist_lock);
1144                 p = find_task_by_pid(pid);
1145
1146                 retval = -ESRCH;
1147                 if(p) {
1148                         retval = security_task_getsid(p);
1149                         if (!retval)
1150                                 retval = p->signal->session;
1151                 }
1152                 read_unlock(&tasklist_lock);
1153                 return retval;
1154         }
1155 }
1156
1157 asmlinkage long sys_setsid(void)
1158 {
1159         struct pid *pid;
1160         int err = -EPERM;
1161
1162         if (!thread_group_leader(current))
1163                 return -EINVAL;
1164
1165         write_lock_irq(&tasklist_lock);
1166
1167         pid = find_pid(PIDTYPE_PGID, current->pid);
1168         if (pid)
1169                 goto out;
1170
1171         current->signal->leader = 1;
1172         __set_special_pids(current->pid, current->pid);
1173         current->signal->tty = NULL;
1174         current->signal->tty_old_pgrp = 0;
1175         err = process_group(current);
1176 out:
1177         write_unlock_irq(&tasklist_lock);
1178         return err;
1179 }
1180
1181 /*
1182  * Supplementary group IDs
1183  */
1184
1185 /* init to 2 - one for init_task, one to ensure it is never freed */
1186 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1187
1188 struct group_info *groups_alloc(int gidsetsize)
1189 {
1190         struct group_info *group_info;
1191         int nblocks;
1192         int i;
1193
1194         nblocks = (gidsetsize/NGROUPS_PER_BLOCK) +
1195             (gidsetsize%NGROUPS_PER_BLOCK?1:0);
1196         group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *),
1197             GFP_USER);
1198         if (!group_info)
1199                 return NULL;
1200         group_info->ngroups = gidsetsize;
1201         group_info->nblocks = nblocks;
1202         atomic_set(&group_info->usage, 1);
1203
1204         if (gidsetsize <= NGROUPS_SMALL) {
1205                 group_info->blocks[0] = group_info->small_block;
1206         } else {
1207                 for (i = 0; i < nblocks; i++) {
1208                         gid_t *b;
1209                         b = (void *)__get_free_page(GFP_USER);
1210                         if (!b)
1211                                 goto out_undo_partial_alloc;
1212                         group_info->blocks[i] = b;
1213                 }
1214         }
1215         return group_info;
1216
1217 out_undo_partial_alloc:
1218         while (--i >= 0) {
1219                 free_page((unsigned long)group_info->blocks[i]);
1220         }
1221         kfree(group_info);
1222         return NULL;
1223 }
1224
1225 EXPORT_SYMBOL(groups_alloc);
1226
1227 void groups_free(struct group_info *group_info)
1228 {
1229         if (group_info->blocks[0] != group_info->small_block) {
1230                 int i;
1231                 for (i = 0; i < group_info->nblocks; i++)
1232                         free_page((unsigned long)group_info->blocks[i]);
1233         }
1234         kfree(group_info);
1235 }
1236
1237 EXPORT_SYMBOL(groups_free);
1238
1239 /* export the group_info to a user-space array */
1240 static int groups_to_user(gid_t __user *grouplist,
1241     struct group_info *group_info)
1242 {
1243         int i;
1244         int count = group_info->ngroups;
1245
1246         for (i = 0; i < group_info->nblocks; i++) {
1247                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1248                 int off = i * NGROUPS_PER_BLOCK;
1249                 int len = cp_count * sizeof(*grouplist);
1250
1251                 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1252                         return -EFAULT;
1253
1254                 count -= cp_count;
1255         }
1256         return 0;
1257 }
1258
1259 /* fill a group_info from a user-space array - it must be allocated already */
1260 static int groups_from_user(struct group_info *group_info,
1261     gid_t __user *grouplist)
1262  {
1263         int i;
1264         int count = group_info->ngroups;
1265
1266         for (i = 0; i < group_info->nblocks; i++) {
1267                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1268                 int off = i * NGROUPS_PER_BLOCK;
1269                 int len = cp_count * sizeof(*grouplist);
1270
1271                 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1272                         return -EFAULT;
1273
1274                 count -= cp_count;
1275         }
1276         return 0;
1277 }
1278
1279 /* a simple shell-metzner sort */
1280 static void groups_sort(struct group_info *group_info)
1281 {
1282         int base, max, stride;
1283         int gidsetsize = group_info->ngroups;
1284
1285         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1286                 ; /* nothing */
1287         stride /= 3;
1288
1289         while (stride) {
1290                 max = gidsetsize - stride;
1291                 for (base = 0; base < max; base++) {
1292                         int left = base;
1293                         int right = left + stride;
1294                         gid_t tmp = GROUP_AT(group_info, right);
1295
1296                         while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1297                                 GROUP_AT(group_info, right) =
1298                                     GROUP_AT(group_info, left);
1299                                 right = left;
1300                                 left -= stride;
1301                         }
1302                         GROUP_AT(group_info, right) = tmp;
1303                 }
1304                 stride /= 3;
1305         }
1306 }
1307
1308 /* a simple bsearch */
1309 static int groups_search(struct group_info *group_info, gid_t grp)
1310 {
1311         int left, right;
1312
1313         if (!group_info)
1314                 return 0;
1315
1316         left = 0;
1317         right = group_info->ngroups;
1318         while (left < right) {
1319                 int mid = (left+right)/2;
1320                 int cmp = grp - GROUP_AT(group_info, mid);
1321                 if (cmp > 0)
1322                         left = mid + 1;
1323                 else if (cmp < 0)
1324                         right = mid;
1325                 else
1326                         return 1;
1327         }
1328         return 0;
1329 }
1330
1331 /* validate and set current->group_info */
1332 int set_current_groups(struct group_info *group_info)
1333 {
1334         int retval;
1335         struct group_info *old_info;
1336
1337         retval = security_task_setgroups(group_info);
1338         if (retval)
1339                 return retval;
1340
1341         groups_sort(group_info);
1342         get_group_info(group_info);
1343         old_info = current->group_info;
1344         current->group_info = group_info;
1345         put_group_info(old_info);
1346
1347         return 0;
1348 }
1349
1350 EXPORT_SYMBOL(set_current_groups);
1351
1352 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1353 {
1354         int i = 0;
1355
1356         /*
1357          *      SMP: Nobody else can change our grouplist. Thus we are
1358          *      safe.
1359          */
1360
1361         if (gidsetsize < 0)
1362                 return -EINVAL;
1363
1364         get_group_info(current->group_info);
1365         i = current->group_info->ngroups;
1366         if (gidsetsize) {
1367                 if (i > gidsetsize) {
1368                         i = -EINVAL;
1369                         goto out;
1370                 }
1371                 if (groups_to_user(grouplist, current->group_info)) {
1372                         i = -EFAULT;
1373                         goto out;
1374                 }
1375         }
1376 out:
1377         put_group_info(current->group_info);
1378         return i;
1379 }
1380
1381 /*
1382  *      SMP: Our groups are copy-on-write. We can set them safely
1383  *      without another task interfering.
1384  */
1385
1386 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1387 {
1388         struct group_info *group_info;
1389         int retval;
1390
1391         if (!capable(CAP_SETGID))
1392                 return -EPERM;
1393         if ((unsigned)gidsetsize > NGROUPS_MAX)
1394                 return -EINVAL;
1395
1396         group_info = groups_alloc(gidsetsize);
1397         if (!group_info)
1398                 return -ENOMEM;
1399         retval = groups_from_user(group_info, grouplist);
1400         if (retval) {
1401                 put_group_info(group_info);
1402                 return retval;
1403         }
1404
1405         retval = set_current_groups(group_info);
1406         put_group_info(group_info);
1407
1408         return retval;
1409 }
1410
1411 /*
1412  * Check whether we're fsgid/egid or in the supplemental group..
1413  */
1414 int in_group_p(gid_t grp)
1415 {
1416         int retval = 1;
1417         if (grp != current->fsgid) {
1418                 get_group_info(current->group_info);
1419                 retval = groups_search(current->group_info, grp);
1420                 put_group_info(current->group_info);
1421         }
1422         return retval;
1423 }
1424
1425 EXPORT_SYMBOL(in_group_p);
1426
1427 int in_egroup_p(gid_t grp)
1428 {
1429         int retval = 1;
1430         if (grp != current->egid) {
1431                 get_group_info(current->group_info);
1432                 retval = groups_search(current->group_info, grp);
1433                 put_group_info(current->group_info);
1434         }
1435         return retval;
1436 }
1437
1438 EXPORT_SYMBOL(in_egroup_p);
1439
1440 DECLARE_RWSEM(uts_sem);
1441
1442 EXPORT_SYMBOL(uts_sem);
1443
1444 asmlinkage long sys_newuname(struct new_utsname __user * name)
1445 {
1446         int errno = 0;
1447
1448         down_read(&uts_sem);
1449         if (copy_to_user(name, vx_new_utsname(), sizeof *name))
1450                 errno = -EFAULT;
1451         up_read(&uts_sem);
1452         return errno;
1453 }
1454
1455 asmlinkage long sys_sethostname(char __user *name, int len)
1456 {
1457         int errno;
1458         char tmp[__NEW_UTS_LEN];
1459
1460         if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SET_UTSNAME))
1461                 return -EPERM;
1462         if (len < 0 || len > __NEW_UTS_LEN)
1463                 return -EINVAL;
1464         down_write(&uts_sem);
1465         errno = -EFAULT;
1466         if (!copy_from_user(tmp, name, len)) {
1467                 char *ptr = vx_new_uts(nodename);
1468
1469                 memcpy(ptr, tmp, len);
1470                 ptr[len] = 0;
1471                 errno = 0;
1472         }
1473         up_write(&uts_sem);
1474         return errno;
1475 }
1476
1477 asmlinkage long sys_gethostname(char __user *name, int len)
1478 {
1479         int i, errno;
1480         char *ptr;
1481
1482         if (len < 0)
1483                 return -EINVAL;
1484         down_read(&uts_sem);
1485         ptr = vx_new_uts(nodename);
1486         i = 1 + strlen(ptr);
1487         if (i > len)
1488                 i = len;
1489         errno = 0;
1490         if (copy_to_user(name, ptr, i))
1491                 errno = -EFAULT;
1492         up_read(&uts_sem);
1493         return errno;
1494 }
1495
1496 /*
1497  * Only setdomainname; getdomainname can be implemented by calling
1498  * uname()
1499  */
1500 asmlinkage long sys_setdomainname(char __user *name, int len)
1501 {
1502         int errno;
1503         char tmp[__NEW_UTS_LEN];
1504
1505         if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SET_UTSNAME))
1506                 return -EPERM;
1507         if (len < 0 || len > __NEW_UTS_LEN)
1508                 return -EINVAL;
1509
1510         down_write(&uts_sem);
1511         errno = -EFAULT;
1512         if (!copy_from_user(tmp, name, len)) {
1513                 char *ptr = vx_new_uts(domainname);
1514
1515                 memcpy(ptr, tmp, len);
1516                 ptr[len] = 0;
1517                 errno = 0;
1518         }
1519         up_write(&uts_sem);
1520         return errno;
1521 }
1522
1523 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1524 {
1525         if (resource >= RLIM_NLIMITS)
1526                 return -EINVAL;
1527         else
1528                 return copy_to_user(rlim, current->rlim + resource, sizeof(*rlim))
1529                         ? -EFAULT : 0;
1530 }
1531
1532 #if defined(COMPAT_RLIM_OLD_INFINITY) || !(defined(CONFIG_IA64) || defined(CONFIG_V850))
1533
1534 /*
1535  *      Back compatibility for getrlimit. Needed for some apps.
1536  */
1537
1538 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1539 {
1540         struct rlimit x;
1541         if (resource >= RLIM_NLIMITS)
1542                 return -EINVAL;
1543
1544         memcpy(&x, current->rlim + resource, sizeof(*rlim));
1545         if(x.rlim_cur > 0x7FFFFFFF)
1546                 x.rlim_cur = 0x7FFFFFFF;
1547         if(x.rlim_max > 0x7FFFFFFF)
1548                 x.rlim_max = 0x7FFFFFFF;
1549         return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1550 }
1551
1552 #endif
1553
1554 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1555 {
1556         struct rlimit new_rlim, *old_rlim;
1557         int retval;
1558
1559         if (resource >= RLIM_NLIMITS)
1560                 return -EINVAL;
1561         if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1562                 return -EFAULT;
1563        if (new_rlim.rlim_cur > new_rlim.rlim_max)
1564                return -EINVAL;
1565         old_rlim = current->rlim + resource;
1566         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
1567              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
1568             !capable(CAP_SYS_RESOURCE) && vx_ccaps(VXC_SET_RLIMIT))
1569                 return -EPERM;
1570         if (resource == RLIMIT_NOFILE) {
1571                 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
1572                         return -EPERM;
1573         }
1574
1575         retval = security_task_setrlimit(resource, &new_rlim);
1576         if (retval)
1577                 return retval;
1578
1579         *old_rlim = new_rlim;
1580         return 0;
1581 }
1582
1583 /*
1584  * It would make sense to put struct rusage in the task_struct,
1585  * except that would make the task_struct be *really big*.  After
1586  * task_struct gets moved into malloc'ed memory, it would
1587  * make sense to do this.  It will make moving the rest of the information
1588  * a lot simpler!  (Which we're not doing right now because we're not
1589  * measuring them yet).
1590  *
1591  * This is SMP safe.  Either we are called from sys_getrusage on ourselves
1592  * below (we know we aren't going to exit/disappear and only we change our
1593  * rusage counters), or we are called from wait4() on a process which is
1594  * either stopped or zombied.  In the zombied case the task won't get
1595  * reaped till shortly after the call to getrusage(), in both cases the
1596  * task being examined is in a frozen state so the counters won't change.
1597  */
1598 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1599 {
1600         struct rusage r;
1601
1602         memset((char *) &r, 0, sizeof(r));
1603         switch (who) {
1604                 case RUSAGE_SELF:
1605                         jiffies_to_timeval(p->utime, &r.ru_utime);
1606                         jiffies_to_timeval(p->stime, &r.ru_stime);
1607                         r.ru_nvcsw = p->nvcsw;
1608                         r.ru_nivcsw = p->nivcsw;
1609                         r.ru_minflt = p->min_flt;
1610                         r.ru_majflt = p->maj_flt;
1611                         break;
1612                 case RUSAGE_CHILDREN:
1613                         jiffies_to_timeval(p->cutime, &r.ru_utime);
1614                         jiffies_to_timeval(p->cstime, &r.ru_stime);
1615                         r.ru_nvcsw = p->cnvcsw;
1616                         r.ru_nivcsw = p->cnivcsw;
1617                         r.ru_minflt = p->cmin_flt;
1618                         r.ru_majflt = p->cmaj_flt;
1619                         break;
1620                 default:
1621                         jiffies_to_timeval(p->utime + p->cutime, &r.ru_utime);
1622                         jiffies_to_timeval(p->stime + p->cstime, &r.ru_stime);
1623                         r.ru_nvcsw = p->nvcsw + p->cnvcsw;
1624                         r.ru_nivcsw = p->nivcsw + p->cnivcsw;
1625                         r.ru_minflt = p->min_flt + p->cmin_flt;
1626                         r.ru_majflt = p->maj_flt + p->cmaj_flt;
1627                         break;
1628         }
1629         return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1630 }
1631
1632 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1633 {
1634         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1635                 return -EINVAL;
1636         return getrusage(current, who, ru);
1637 }
1638
1639 asmlinkage long sys_umask(int mask)
1640 {
1641         mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1642         return mask;
1643 }
1644
1645 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1646                           unsigned long arg4, unsigned long arg5)
1647 {
1648         int error;
1649         int sig;
1650
1651         error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1652         if (error)
1653                 return error;
1654
1655         switch (option) {
1656                 case PR_SET_PDEATHSIG:
1657                         sig = arg2;
1658                         if (sig < 0 || sig > _NSIG) {
1659                                 error = -EINVAL;
1660                                 break;
1661                         }
1662                         current->pdeath_signal = sig;
1663                         break;
1664                 case PR_GET_PDEATHSIG:
1665                         error = put_user(current->pdeath_signal, (int __user *)arg2);
1666                         break;
1667                 case PR_GET_DUMPABLE:
1668                         if (current->mm->dumpable)
1669                                 error = 1;
1670                         break;
1671                 case PR_SET_DUMPABLE:
1672                         if (arg2 != 0 && arg2 != 1) {
1673                                 error = -EINVAL;
1674                                 break;
1675                         }
1676                         current->mm->dumpable = arg2;
1677                         break;
1678
1679                 case PR_SET_UNALIGN:
1680                         error = SET_UNALIGN_CTL(current, arg2);
1681                         break;
1682                 case PR_GET_UNALIGN:
1683                         error = GET_UNALIGN_CTL(current, arg2);
1684                         break;
1685                 case PR_SET_FPEMU:
1686                         error = SET_FPEMU_CTL(current, arg2);
1687                         break;
1688                 case PR_GET_FPEMU:
1689                         error = GET_FPEMU_CTL(current, arg2);
1690                         break;
1691                 case PR_SET_FPEXC:
1692                         error = SET_FPEXC_CTL(current, arg2);
1693                         break;
1694                 case PR_GET_FPEXC:
1695                         error = GET_FPEXC_CTL(current, arg2);
1696                         break;
1697                 case PR_GET_TIMING:
1698                         error = PR_TIMING_STATISTICAL;
1699                         break;
1700                 case PR_SET_TIMING:
1701                         if (arg2 == PR_TIMING_STATISTICAL)
1702                                 error = 0;
1703                         else
1704                                 error = -EINVAL;
1705                         break;
1706
1707                 case PR_GET_KEEPCAPS:
1708                         if (current->keep_capabilities)
1709                                 error = 1;
1710                         break;
1711                 case PR_SET_KEEPCAPS:
1712                         if (arg2 != 0 && arg2 != 1) {
1713                                 error = -EINVAL;
1714                                 break;
1715                         }
1716                         current->keep_capabilities = arg2;
1717                         break;
1718                 default:
1719                         error = -EINVAL;
1720                         break;
1721         }
1722         return error;
1723 }