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/kernel.h>
  22 #include <linux/kexec.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/device.h>
  25 #include <linux/times.h>
  26 #include <linux/security.h>
  27 #include <linux/dcookies.h>
  28 #include <linux/suspend.h>
  29 #include <linux/ckrm.h>
  30 #include <linux/vs_base.h>
  31 #include <linux/vs_cvirt.h>
  32
  33 #include <asm/uaccess.h>
  34 #include <asm/io.h>
  35 #include <asm/unistd.h>
  36
  37 #ifndef SET_UNALIGN_CTL
  38 # define SET_UNALIGN_CTL(a,b)   (-EINVAL)
  39 #endif
  40 #ifndef GET_UNALIGN_CTL
  41 # define GET_UNALIGN_CTL(a,b)   (-EINVAL)
  42 #endif
  43 #ifndef SET_FPEMU_CTL
  44 # define SET_FPEMU_CTL(a,b)     (-EINVAL)
  45 #endif
  46 #ifndef GET_FPEMU_CTL
  47 # define GET_FPEMU_CTL(a,b)     (-EINVAL)
  48 #endif
  49 #ifndef SET_FPEXC_CTL
  50 # define SET_FPEXC_CTL(a,b)     (-EINVAL)
  51 #endif
  52 #ifndef GET_FPEXC_CTL
  53 # define GET_FPEXC_CTL(a,b)     (-EINVAL)
  54 #endif
  55
  56 /*
  57  * this is where the system-wide overflow UID and GID are defined, for
  58  * architectures that now have 32-bit UID/GID but didn't in the past
  59  */
  60
  61 int overflowuid = DEFAULT_OVERFLOWUID;
  62 int overflowgid = DEFAULT_OVERFLOWGID;
  63
  64 #ifdef CONFIG_UID16
  65 EXPORT_SYMBOL(overflowuid);
  66 EXPORT_SYMBOL(overflowgid);
  67 #endif
  68
  69 /*
  70  * the same as above, but for filesystems which can only store a 16-bit
  71  * UID and GID. as such, this is needed on all architectures
  72  */
  73
  74 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
  75 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
  76
  77 EXPORT_SYMBOL(fs_overflowuid);
  78 EXPORT_SYMBOL(fs_overflowgid);
  79
  80 /*
  81  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
  82  */
  83
  84 int C_A_D = 1;
  85 int cad_pid = 1;
  86
  87 /*
  88  *      Notifier list for kernel code which wants to be called
  89  *      at shutdown. This is used to stop any idling DMA operations
  90  *      and the like.
  91  */
  92
  93 static struct notifier_block *reboot_notifier_list;
  94 rwlock_t notifier_lock = RW_LOCK_UNLOCKED;
  95
  96 /**
  97  *      notifier_chain_register - Add notifier to a notifier chain
  98  *      @list: Pointer to root list pointer
  99  *      @n: New entry in notifier chain
 100  *
 101  *      Adds a notifier to a notifier chain.
 102  *
 103  *      Currently always returns zero.
 104  */
 105
 106 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
 107 {
 108         write_lock(&notifier_lock);
 109         while(*list)
 110         {
 111                 if(n->priority > (*list)->priority)
 112                         break;
 113                 list= &((*list)->next);
 114         }
 115         n->next = *list;
 116         *list=n;
 117         write_unlock(&notifier_lock);
 118         return 0;
 119 }
 120
 121 EXPORT_SYMBOL(notifier_chain_register);
 122
 123 /**
 124  *      notifier_chain_unregister - Remove notifier from a notifier chain
 125  *      @nl: Pointer to root list pointer
 126  *      @n: New entry in notifier chain
 127  *
 128  *      Removes a notifier from a notifier chain.
 129  *
 130  *      Returns zero on success, or %-ENOENT on failure.
 131  */
 132
 133 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
 134 {
 135         write_lock(&notifier_lock);
 136         while((*nl)!=NULL)
 137         {
 138                 if((*nl)==n)
 139                 {
 140                         *nl=n->next;
 141                         write_unlock(&notifier_lock);
 142                         return 0;
 143                 }
 144                 nl=&((*nl)->next);
 145         }
 146         write_unlock(&notifier_lock);
 147         return -ENOENT;
 148 }
 149
 150 EXPORT_SYMBOL(notifier_chain_unregister);
 151
 152 /**
 153  *      notifier_call_chain - Call functions in a notifier chain
 154  *      @n: Pointer to root pointer of notifier chain
 155  *      @val: Value passed unmodified to notifier function
 156  *      @v: Pointer passed unmodified to notifier function
 157  *
 158  *      Calls each function in a notifier chain in turn.
 159  *
 160  *      If the return value of the notifier can be and'd
 161  *      with %NOTIFY_STOP_MASK, then notifier_call_chain
 162  *      will return immediately, with the return value of
 163  *      the notifier function which halted execution.
 164  *      Otherwise, the return value is the return value
 165  *      of the last notifier function called.
 166  */
 167
 168 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
 169 {
 170         int ret=NOTIFY_DONE;
 171         struct notifier_block *nb = *n;
 172
 173         while(nb)
 174         {
 175                 ret=nb->notifier_call(nb,val,v);
 176                 if(ret&NOTIFY_STOP_MASK)
 177                 {
 178                         return ret;
 179                 }
 180                 nb=nb->next;
 181         }
 182         return ret;
 183 }
 184
 185 EXPORT_SYMBOL(notifier_call_chain);
 186
 187 /**
 188  *      register_reboot_notifier - Register function to be called at reboot time
 189  *      @nb: Info about notifier function to be called
 190  *
 191  *      Registers a function with the list of functions
 192  *      to be called at reboot time.
 193  *
 194  *      Currently always returns zero, as notifier_chain_register
 195  *      always returns zero.
 196  */
 197
 198 int register_reboot_notifier(struct notifier_block * nb)
 199 {
 200         return notifier_chain_register(&reboot_notifier_list, nb);
 201 }
 202
 203 EXPORT_SYMBOL(register_reboot_notifier);
 204
 205 /**
 206  *      unregister_reboot_notifier - Unregister previously registered reboot notifier
 207  *      @nb: Hook to be unregistered
 208  *
 209  *      Unregisters a previously registered reboot
 210  *      notifier function.
 211  *
 212  *      Returns zero on success, or %-ENOENT on failure.
 213  */
 214
 215 int unregister_reboot_notifier(struct notifier_block * nb)
 216 {
 217         return notifier_chain_unregister(&reboot_notifier_list, nb);
 218 }
 219
 220 EXPORT_SYMBOL(unregister_reboot_notifier);
 221
 222 asmlinkage long sys_ni_syscall(void)
 223 {
 224         return -ENOSYS;
 225 }
 226
 227 cond_syscall(sys_nfsservctl)
 228 cond_syscall(sys_quotactl)
 229 cond_syscall(sys_acct)
 230 cond_syscall(sys_lookup_dcookie)
 231 cond_syscall(sys_swapon)
 232 cond_syscall(sys_swapoff)
 233 cond_syscall(sys_kexec_load)
 234 cond_syscall(sys_init_module)
 235 cond_syscall(sys_delete_module)
 236 cond_syscall(sys_socketpair)
 237 cond_syscall(sys_bind)
 238 cond_syscall(sys_listen)
 239 cond_syscall(sys_accept)
 240 cond_syscall(sys_connect)
 241 cond_syscall(sys_getsockname)
 242 cond_syscall(sys_getpeername)
 243 cond_syscall(sys_sendto)
 244 cond_syscall(sys_send)
 245 cond_syscall(sys_recvfrom)
 246 cond_syscall(sys_recv)
 247 cond_syscall(sys_socket)
 248 cond_syscall(sys_setsockopt)
 249 cond_syscall(sys_getsockopt)
 250 cond_syscall(sys_shutdown)
 251 cond_syscall(sys_sendmsg)
 252 cond_syscall(sys_recvmsg)
 253 cond_syscall(sys_socketcall)
 254 cond_syscall(sys_futex)
 255 cond_syscall(compat_sys_futex)
 256 cond_syscall(sys_epoll_create)
 257 cond_syscall(sys_epoll_ctl)
 258 cond_syscall(sys_epoll_wait)
 259 cond_syscall(sys_semget)
 260 cond_syscall(sys_semop)
 261 cond_syscall(sys_semtimedop)
 262 cond_syscall(sys_semctl)
 263 cond_syscall(sys_msgget)
 264 cond_syscall(sys_msgsnd)
 265 cond_syscall(sys_msgrcv)
 266 cond_syscall(sys_msgctl)
 267 cond_syscall(sys_shmget)
 268 cond_syscall(sys_shmdt)
 269 cond_syscall(sys_shmctl)
 270 cond_syscall(sys_mq_open)
 271 cond_syscall(sys_mq_unlink)
 272 cond_syscall(sys_mq_timedsend)
 273 cond_syscall(sys_mq_timedreceive)
 274 cond_syscall(sys_mq_notify)
 275 cond_syscall(sys_mq_getsetattr)
 276 cond_syscall(compat_sys_mq_open)
 277 cond_syscall(compat_sys_mq_timedsend)
 278 cond_syscall(compat_sys_mq_timedreceive)
 279 cond_syscall(compat_sys_mq_notify)
 280 cond_syscall(compat_sys_mq_getsetattr)
 281 cond_syscall(sys_mbind)
 282 cond_syscall(sys_get_mempolicy)
 283 cond_syscall(sys_set_mempolicy)
 284 cond_syscall(compat_mbind)
 285 cond_syscall(compat_get_mempolicy)
 286 cond_syscall(compat_set_mempolicy)
 287
 288 /* arch-specific weak syscall entries */
 289 cond_syscall(sys_pciconfig_read)
 290 cond_syscall(sys_pciconfig_write)
 291 cond_syscall(sys_pciconfig_iobase)
 292
 293 static int set_one_prio(struct task_struct *p, int niceval, int error)
 294 {
 295         int no_nice;
 296
 297         if (p->uid != current->euid &&
 298                 p->uid != current->uid && !capable(CAP_SYS_NICE)) {
 299                 error = -EPERM;
 300                 goto out;
 301         }
 302         if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) {
 303                 if (vx_flags(VXF_IGNEG_NICE, 0))
 304                         error = 0;
 305                 else
 306                         error = -EACCES;
 307                 goto out;
 308         }
 309         no_nice = security_task_setnice(p, niceval);
 310         if (no_nice) {
 311                 error = no_nice;
 312                 goto out;
 313         }
 314         if (error == -ESRCH)
 315                 error = 0;
 316         set_user_nice(p, niceval);
 317 out:
 318         return error;
 319 }
 320
 321 asmlinkage long sys_setpriority(int which, int who, int niceval)
 322 {
 323         struct task_struct *g, *p;
 324         struct user_struct *user;
 325         int error = -EINVAL;
 326
 327         if (which > 2 || which < 0)
 328                 goto out;
 329
 330         /* normalize: avoid signed division (rounding problems) */
 331         error = -ESRCH;
 332         if (niceval < -20)
 333                 niceval = -20;
 334         if (niceval > 19)
 335                 niceval = 19;
 336
 337         read_lock(&tasklist_lock);
 338         switch (which) {
 339                 case PRIO_PROCESS:
 340                         if (!who)
 341                                 who = current->pid;
 342                         p = find_task_by_pid(who);
 343                         if (p)
 344                                 error = set_one_prio(p, niceval, error);
 345                         break;
 346                 case PRIO_PGRP:
 347                         if (!who)
 348                                 who = process_group(current);
 349                         do_each_task_pid(who, PIDTYPE_PGID, p) {
 350                                 error = set_one_prio(p, niceval, error);
 351                         } while_each_task_pid(who, PIDTYPE_PGID, p);
 352                         break;
 353                 case PRIO_USER:
 354                         if (!who)
 355                                 user = current->user;
 356                         else
 357                                 user = find_user(vx_current_xid(), who);
 358
 359                         if (!user)
 360                                 goto out_unlock;
 361
 362                         do_each_thread(g, p)
 363                                 if (p->uid == who)
 364                                         error = set_one_prio(p, niceval, error);
 365                         while_each_thread(g, p);
 366                         if (who)
 367                                 free_uid(user);         /* For find_user() */
 368                         break;
 369         }
 370 out_unlock:
 371         read_unlock(&tasklist_lock);
 372 out:
 373         return error;
 374 }
 375
 376 /*
 377  * Ugh. To avoid negative return values, "getpriority()" will
 378  * not return the normal nice-value, but a negated value that
 379  * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 380  * to stay compatible.
 381  */
 382 asmlinkage long sys_getpriority(int which, int who)
 383 {
 384         struct task_struct *g, *p;
 385         struct user_struct *user;
 386         long niceval, retval = -ESRCH;
 387
 388         if (which > 2 || which < 0)
 389                 return -EINVAL;
 390
 391         read_lock(&tasklist_lock);
 392         switch (which) {
 393                 case PRIO_PROCESS:
 394                         if (!who)
 395                                 who = current->pid;
 396                         p = find_task_by_pid(who);
 397                         if (p) {
 398                                 niceval = 20 - task_nice(p);
 399                                 if (niceval > retval)
 400                                         retval = niceval;
 401                         }
 402                         break;
 403                 case PRIO_PGRP:
 404                         if (!who)
 405                                 who = process_group(current);
 406                         do_each_task_pid(who, PIDTYPE_PGID, p) {
 407                                 niceval = 20 - task_nice(p);
 408                                 if (niceval > retval)
 409                                         retval = niceval;
 410                         } while_each_task_pid(who, PIDTYPE_PGID, p);
 411                         break;
 412                 case PRIO_USER:
 413                         if (!who)
 414                                 user = current->user;
 415                         else
 416                                 user = find_user(vx_current_xid(), who);
 417
 418                         if (!user)
 419                                 goto out_unlock;
 420
 421                         do_each_thread(g, p)
 422                                 if (p->uid == who) {
 423                                         niceval = 20 - task_nice(p);
 424                                         if (niceval > retval)
 425                                                 retval = niceval;
 426                                 }
 427                         while_each_thread(g, p);
 428                         if (who)
 429                                 free_uid(user);         /* for find_user() */
 430                         break;
 431         }
 432 out_unlock:
 433         read_unlock(&tasklist_lock);
 434
 435         return retval;
 436 }
 437
 438 long vs_reboot(unsigned int, void *);
 439
 440 /*
 441  * Reboot system call: for obvious reasons only root may call it,
 442  * and even root needs to set up some magic numbers in the registers
 443  * so that some mistake won't make this reboot the whole machine.
 444  * You can also set the meaning of the ctrl-alt-del-key here.
 445  *
 446  * reboot doesn't sync: do that yourself before calling this.
 447  */
 448 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
 449 {
 450         char buffer[256];
 451
 452         /* We only trust the superuser with rebooting the system. */
 453         if (!capable(CAP_SYS_BOOT))
 454                 return -EPERM;
 455
 456         /* For safety, we require "magic" arguments. */
 457         if (magic1 != LINUX_REBOOT_MAGIC1 ||
 458             (magic2 != LINUX_REBOOT_MAGIC2 &&
 459                         magic2 != LINUX_REBOOT_MAGIC2A &&
 460                         magic2 != LINUX_REBOOT_MAGIC2B &&
 461                         magic2 != LINUX_REBOOT_MAGIC2C))
 462                 return -EINVAL;
 463
 464         if (!vx_check(0, VX_ADMIN|VX_WATCH))
 465                 return vs_reboot(cmd, arg);
 466
 467         lock_kernel();
 468         switch (cmd) {
 469         case LINUX_REBOOT_CMD_RESTART:
 470                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 471                 system_state = SYSTEM_RESTART;
 472                 device_shutdown();
 473                 printk(KERN_EMERG "Restarting system.\n");
 474                 machine_restart(NULL);
 475                 break;
 476
 477         case LINUX_REBOOT_CMD_CAD_ON:
 478                 C_A_D = 1;
 479                 break;
 480
 481         case LINUX_REBOOT_CMD_CAD_OFF:
 482                 C_A_D = 0;
 483                 break;
 484
 485         case LINUX_REBOOT_CMD_HALT:
 486                 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
 487                 system_state = SYSTEM_HALT;
 488                 device_shutdown();
 489                 printk(KERN_EMERG "System halted.\n");
 490                 machine_halt();
 491                 unlock_kernel();
 492                 do_exit(0);
 493                 break;
 494
 495         case LINUX_REBOOT_CMD_POWER_OFF:
 496                 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
 497                 system_state = SYSTEM_POWER_OFF;
 498                 device_shutdown();
 499                 printk(KERN_EMERG "Power down.\n");
 500                 machine_power_off();
 501                 unlock_kernel();
 502                 do_exit(0);
 503                 break;
 504
 505         case LINUX_REBOOT_CMD_RESTART2:
 506                 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
 507                         unlock_kernel();
 508                         return -EFAULT;
 509                 }
 510                 buffer[sizeof(buffer) - 1] = '\0';
 511
 512                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
 513                 system_state = SYSTEM_RESTART;
 514                 device_shutdown();
 515                 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
 516                 machine_restart(buffer);
 517                 break;
 518
 519 #ifdef CONFIG_KEXEC
 520         case LINUX_REBOOT_CMD_KEXEC:
 521         {
 522                 struct kimage *image;
 523                 image = xchg(&kexec_image, 0);
 524                 if (!image) {
 525                         unlock_kernel();
 526                         return -EINVAL;
 527                 }
 528                 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 529                 system_state = SYSTEM_RESTART;
 530                 device_shutdown();
 531                 system_state = SYSTEM_BOOTING;
 532                 printk(KERN_EMERG "Starting new kernel\n");
 533                 machine_shutdown();
 534                 machine_kexec(image);
 535                 break;
 536         }
 537 #endif
 538 #ifdef CONFIG_SOFTWARE_SUSPEND
 539         case LINUX_REBOOT_CMD_SW_SUSPEND:
 540                 {
 541                         int ret = software_suspend();
 542                         unlock_kernel();
 543                         return ret;
 544                 }
 545 #endif
 546
 547         default:
 548                 unlock_kernel();
 549                 return -EINVAL;
 550         }
 551         unlock_kernel();
 552         return 0;
 553 }
 554
 555 static void deferred_cad(void *dummy)
 556 {
 557         notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
 558         machine_restart(NULL);
 559 }
 560
 561 /*
 562  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 563  * As it's called within an interrupt, it may NOT sync: the only choice
 564  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 565  */
 566 void ctrl_alt_del(void)
 567 {
 568         static DECLARE_WORK(cad_work, deferred_cad, NULL);
 569
 570         if (C_A_D)
 571                 schedule_work(&cad_work);
 572         else
 573                 kill_proc(cad_pid, SIGINT, 1);
 574 }
 575
 576
 577 /*
 578  * Unprivileged users may change the real gid to the effective gid
 579  * or vice versa.  (BSD-style)
 580  *
 581  * If you set the real gid at all, or set the effective gid to a value not
 582  * equal to the real gid, then the saved gid is set to the new effective gid.
 583  *
 584  * This makes it possible for a setgid program to completely drop its
 585  * privileges, which is often a useful assertion to make when you are doing
 586  * a security audit over a program.
 587  *
 588  * The general idea is that a program which uses just setregid() will be
 589  * 100% compatible with BSD.  A program which uses just setgid() will be
 590  * 100% compatible with POSIX with saved IDs.
 591  *
 592  * SMP: There are not races, the GIDs are checked only by filesystem
 593  *      operations (as far as semantic preservation is concerned).
 594  */
 595 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
 596 {
 597         int old_rgid = current->gid;
 598         int old_egid = current->egid;
 599         int new_rgid = old_rgid;
 600         int new_egid = old_egid;
 601         int retval;
 602
 603         retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
 604         if (retval)
 605                 return retval;
 606
 607         if (rgid != (gid_t) -1) {
 608                 if ((old_rgid == rgid) ||
 609                     (current->egid==rgid) ||
 610                     capable(CAP_SETGID))
 611                         new_rgid = rgid;
 612                 else
 613                         return -EPERM;
 614         }
 615         if (egid != (gid_t) -1) {
 616                 if ((old_rgid == egid) ||
 617                     (current->egid == egid) ||
 618                     (current->sgid == egid) ||
 619                     capable(CAP_SETGID))
 620                         new_egid = egid;
 621                 else {
 622                         return -EPERM;
 623                 }
 624         }
 625         if (new_egid != old_egid)
 626         {
 627                 current->mm->dumpable = suid_dumpable;
 628                 wmb();
 629         }
 630         if (rgid != (gid_t) -1 ||
 631             (egid != (gid_t) -1 && egid != old_rgid))
 632                 current->sgid = new_egid;
 633         current->fsgid = new_egid;
 634         current->egid = new_egid;
 635         current->gid = new_rgid;
 636
 637         ckrm_cb_gid();
 638
 639         return 0;
 640 }
 641
 642 /*
 643  * setgid() is implemented like SysV w/ SAVED_IDS
 644  *
 645  * SMP: Same implicit races as above.
 646  */
 647 asmlinkage long sys_setgid(gid_t gid)
 648 {
 649         int old_egid = current->egid;
 650         int retval;
 651
 652         retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
 653         if (retval)
 654                 return retval;
 655
 656         if (capable(CAP_SETGID))
 657         {
 658                 if(old_egid != gid)
 659                 {
 660                         current->mm->dumpable = suid_dumpable;
 661                         wmb();
 662                 }
 663                 current->gid = current->egid = current->sgid = current->fsgid = gid;
 664         }
 665         else if ((gid == current->gid) || (gid == current->sgid))
 666         {
 667                 if(old_egid != gid)
 668                 {
 669                         current->mm->dumpable = suid_dumpable;
 670                         wmb();
 671                 }
 672                 current->egid = current->fsgid = gid;
 673         }
 674         else
 675                 return -EPERM;
 676
 677         ckrm_cb_gid();
 678
 679         return 0;
 680 }
 681
 682 static int set_user(uid_t new_ruid, int dumpclear)
 683 {
 684         struct user_struct *new_user;
 685
 686         new_user = alloc_uid(vx_current_xid(), new_ruid);
 687         if (!new_user)
 688                 return -EAGAIN;
 689
 690         if (atomic_read(&new_user->processes) >=
 691                                 current->rlim[RLIMIT_NPROC].rlim_cur &&
 692                         new_user != &root_user) {
 693                 free_uid(new_user);
 694                 return -EAGAIN;
 695         }
 696
 697         switch_uid(new_user);
 698
 699         if(dumpclear)
 700         {
 701                 current->mm->dumpable = suid_dumpable;
 702                 wmb();
 703         }
 704         current->uid = new_ruid;
 705         return 0;
 706 }
 707
 708 /*
 709  * Unprivileged users may change the real uid to the effective uid
 710  * or vice versa.  (BSD-style)
 711  *
 712  * If you set the real uid at all, or set the effective uid to a value not
 713  * equal to the real uid, then the saved uid is set to the new effective uid.
 714  *
 715  * This makes it possible for a setuid program to completely drop its
 716  * privileges, which is often a useful assertion to make when you are doing
 717  * a security audit over a program.
 718  *
 719  * The general idea is that a program which uses just setreuid() will be
 720  * 100% compatible with BSD.  A program which uses just setuid() will be
 721  * 100% compatible with POSIX with saved IDs.
 722  */
 723 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
 724 {
 725         int old_ruid, old_euid, old_suid, new_ruid, new_euid;
 726         int retval;
 727
 728         retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
 729         if (retval)
 730                 return retval;
 731
 732         new_ruid = old_ruid = current->uid;
 733         new_euid = old_euid = current->euid;
 734         old_suid = current->suid;
 735
 736         if (ruid != (uid_t) -1) {
 737                 new_ruid = ruid;
 738                 if ((old_ruid != ruid) &&
 739                     (current->euid != ruid) &&
 740                     !capable(CAP_SETUID))
 741                         return -EPERM;
 742         }
 743
 744         if (euid != (uid_t) -1) {
 745                 new_euid = euid;
 746                 if ((old_ruid != euid) &&
 747                     (current->euid != euid) &&
 748                     (current->suid != euid) &&
 749                     !capable(CAP_SETUID))
 750                         return -EPERM;
 751         }
 752
 753         if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
 754                 return -EAGAIN;
 755
 756         if (new_euid != old_euid)
 757         {
 758                 current->mm->dumpable = suid_dumpable;
 759                 wmb();
 760         }
 761         current->fsuid = current->euid = new_euid;
 762         if (ruid != (uid_t) -1 ||
 763             (euid != (uid_t) -1 && euid != old_ruid))
 764                 current->suid = current->euid;
 765         current->fsuid = current->euid;
 766
 767         ckrm_cb_uid();
 768
 769         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
 770 }
 771
 772
 773
 774 /*
 775  * setuid() is implemented like SysV with SAVED_IDS
 776  *
 777  * Note that SAVED_ID's is deficient in that a setuid root program
 778  * like sendmail, for example, cannot set its uid to be a normal
 779  * user and then switch back, because if you're root, setuid() sets
 780  * the saved uid too.  If you don't like this, blame the bright people
 781  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 782  * will allow a root program to temporarily drop privileges and be able to
 783  * regain them by swapping the real and effective uid.
 784  */
 785 asmlinkage long sys_setuid(uid_t uid)
 786 {
 787         int old_euid = current->euid;
 788         int old_ruid, old_suid, new_ruid, new_suid;
 789         int retval;
 790
 791         retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
 792         if (retval)
 793                 return retval;
 794
 795         old_ruid = new_ruid = current->uid;
 796         old_suid = current->suid;
 797         new_suid = old_suid;
 798
 799         if (capable(CAP_SETUID)) {
 800                 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
 801                         return -EAGAIN;
 802                 new_suid = uid;
 803         } else if ((uid != current->uid) && (uid != new_suid))
 804                 return -EPERM;
 805
 806         if (old_euid != uid)
 807         {
 808                 current->mm->dumpable = suid_dumpable;
 809                 wmb();
 810         }
 811         current->fsuid = current->euid = uid;
 812         current->suid = new_suid;
 813
 814         ckrm_cb_uid();
 815
 816         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
 817 }
 818
 819
 820 /*
 821  * This function implements a generic ability to update ruid, euid,
 822  * and suid.  This allows you to implement the 4.4 compatible seteuid().
 823  */
 824 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 825 {
 826         int old_ruid = current->uid;
 827         int old_euid = current->euid;
 828         int old_suid = current->suid;
 829         int retval;
 830
 831         retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
 832         if (retval)
 833                 return retval;
 834
 835         if (!capable(CAP_SETUID)) {
 836                 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
 837                     (ruid != current->euid) && (ruid != current->suid))
 838                         return -EPERM;
 839                 if ((euid != (uid_t) -1) && (euid != current->uid) &&
 840                     (euid != current->euid) && (euid != current->suid))
 841                         return -EPERM;
 842                 if ((suid != (uid_t) -1) && (suid != current->uid) &&
 843                     (suid != current->euid) && (suid != current->suid))
 844                         return -EPERM;
 845         }
 846         if (ruid != (uid_t) -1) {
 847                 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
 848                         return -EAGAIN;
 849         }
 850         if (euid != (uid_t) -1) {
 851                 if (euid != current->euid)
 852                 {
 853                         current->mm->dumpable = suid_dumpable;
 854                         wmb();
 855                 }
 856                 current->euid = euid;
 857         }
 858         current->fsuid = current->euid;
 859         if (suid != (uid_t) -1)
 860                 current->suid = suid;
 861
 862         ckrm_cb_uid();
 863
 864         return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
 865 }
 866
 867 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
 868 {
 869         int retval;
 870
 871         if (!(retval = put_user(current->uid, ruid)) &&
 872             !(retval = put_user(current->euid, euid)))
 873                 retval = put_user(current->suid, suid);
 874
 875         return retval;
 876 }
 877
 878 /*
 879  * Same as above, but for rgid, egid, sgid.
 880  */
 881 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 882 {
 883         int retval;
 884
 885         retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
 886         if (retval)
 887                 return retval;
 888
 889         if (!capable(CAP_SETGID)) {
 890                 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
 891                     (rgid != current->egid) && (rgid != current->sgid))
 892                         return -EPERM;
 893                 if ((egid != (gid_t) -1) && (egid != current->gid) &&
 894                     (egid != current->egid) && (egid != current->sgid))
 895                         return -EPERM;
 896                 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
 897                     (sgid != current->egid) && (sgid != current->sgid))
 898                         return -EPERM;
 899         }
 900         if (egid != (gid_t) -1) {
 901                 if (egid != current->egid)
 902                 {
 903                         current->mm->dumpable = suid_dumpable;
 904                         wmb();
 905                 }
 906                 current->egid = egid;
 907         }
 908         current->fsgid = current->egid;
 909         if (rgid != (gid_t) -1)
 910                 current->gid = rgid;
 911         if (sgid != (gid_t) -1)
 912                 current->sgid = sgid;
 913
 914         ckrm_cb_gid();
 915
 916         return 0;
 917 }
 918
 919 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
 920 {
 921         int retval;
 922
 923         if (!(retval = put_user(current->gid, rgid)) &&
 924             !(retval = put_user(current->egid, egid)))
 925                 retval = put_user(current->sgid, sgid);
 926
 927         return retval;
 928 }
 929
 930
 931 /*
 932  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 933  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 934  * whatever uid it wants to). It normally shadows "euid", except when
 935  * explicitly set by setfsuid() or for access..
 936  */
 937 asmlinkage long sys_setfsuid(uid_t uid)
 938 {
 939         int old_fsuid;
 940
 941         old_fsuid = current->fsuid;
 942         if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
 943                 return old_fsuid;
 944
 945         if (uid == current->uid || uid == current->euid ||
 946             uid == current->suid || uid == current->fsuid ||
 947             capable(CAP_SETUID))
 948         {
 949                 if (uid != old_fsuid)
 950                 {
 951                         current->mm->dumpable = suid_dumpable;
 952                         wmb();
 953                 }
 954                 current->fsuid = uid;
 955         }
 956
 957         security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
 958
 959         return old_fsuid;
 960 }
 961
 962 /*
 963  * Samma på svenska..
 964  */
 965 asmlinkage long sys_setfsgid(gid_t gid)
 966 {
 967         int old_fsgid;
 968
 969         old_fsgid = current->fsgid;
 970         if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
 971                 return old_fsgid;
 972
 973         if (gid == current->gid || gid == current->egid ||
 974             gid == current->sgid || gid == current->fsgid ||
 975             capable(CAP_SETGID))
 976         {
 977                 if (gid != old_fsgid)
 978                 {
 979                         current->mm->dumpable = suid_dumpable;
 980                         wmb();
 981                 }
 982                 current->fsgid = gid;
 983         }
 984         return old_fsgid;
 985 }
 986
 987 asmlinkage long sys_times(struct tms __user * tbuf)
 988 {
 989         /*
 990          *      In the SMP world we might just be unlucky and have one of
 991          *      the times increment as we use it. Since the value is an
 992          *      atomically safe type this is just fine. Conceptually its
 993          *      as if the syscall took an instant longer to occur.
 994          */
 995         if (tbuf) {
 996                 struct tms tmp;
 997                 struct task_struct *tsk = current;
 998                 struct task_struct *t;
 999                 unsigned long utime, stime, cutime, cstime;
1000
1001                 read_lock(&tasklist_lock);
1002                 utime = tsk->signal->utime;
1003                 stime = tsk->signal->stime;
1004                 t = tsk;
1005                 do {
1006                         utime += t->utime;
1007                         stime += t->stime;
1008                         t = next_thread(t);
1009                 } while (t != tsk);
1010
1011                 /*
1012                  * While we have tasklist_lock read-locked, no dying thread
1013                  * can be updating current->signal->[us]time.  Instead,
1014                  * we got their counts included in the live thread loop.
1015                  * However, another thread can come in right now and
1016                  * do a wait call that updates current->signal->c[us]time.
1017                  * To make sure we always see that pair updated atomically,
1018                  * we take the siglock around fetching them.
1019                  */
1020                 spin_lock_irq(&tsk->sighand->siglock);
1021                 cutime = tsk->signal->cutime;
1022                 cstime = tsk->signal->cstime;
1023                 spin_unlock_irq(&tsk->sighand->siglock);
1024                 read_unlock(&tasklist_lock);
1025
1026                 tmp.tms_utime = jiffies_to_clock_t(utime);
1027                 tmp.tms_stime = jiffies_to_clock_t(stime);
1028                 tmp.tms_cutime = jiffies_to_clock_t(cutime);
1029                 tmp.tms_cstime = jiffies_to_clock_t(cstime);
1030                 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1031                         return -EFAULT;
1032         }
1033         return (long) jiffies_64_to_clock_t(get_jiffies_64());
1034 }
1035
1036 /*
1037  * This needs some heavy checking ...
1038  * I just haven't the stomach for it. I also don't fully
1039  * understand sessions/pgrp etc. Let somebody who does explain it.
1040  *
1041  * OK, I think I have the protection semantics right.... this is really
1042  * only important on a multi-user system anyway, to make sure one user
1043  * can't send a signal to a process owned by another.  -TYT, 12/12/91
1044  *
1045  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1046  * LBT 04.03.94
1047  */
1048
1049 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1050 {
1051         struct task_struct *p;
1052         int err = -EINVAL;
1053         pid_t rpgid;
1054
1055         if (!pid)
1056                 pid = vx_map_pid(current->pid);
1057         if (!pgid)
1058                 pgid = pid;
1059         if (pgid < 0)
1060                 return -EINVAL;
1061
1062         rpgid = vx_rmap_pid(pgid);
1063
1064         /* From this point forward we keep holding onto the tasklist lock
1065          * so that our parent does not change from under us. -DaveM
1066          */
1067         write_lock_irq(&tasklist_lock);
1068
1069         err = -ESRCH;
1070         p = find_task_by_pid(pid);
1071         if (!p)
1072                 goto out;
1073
1074         err = -EINVAL;
1075         if (!thread_group_leader(p))
1076                 goto out;
1077
1078         if (p->parent == current || p->real_parent == current) {
1079                 err = -EPERM;
1080                 if (p->signal->session != current->signal->session)
1081                         goto out;
1082                 err = -EACCES;
1083                 if (p->did_exec)
1084                         goto out;
1085         } else {
1086                 err = -ESRCH;
1087                 if (p != current)
1088                         goto out;
1089         }
1090
1091         err = -EPERM;
1092         if (p->signal->leader)
1093                 goto out;
1094
1095         if (pgid != pid) {
1096                 struct task_struct *p;
1097
1098                 do_each_task_pid(rpgid, PIDTYPE_PGID, p) {
1099                         if (p->signal->session == current->signal->session)
1100                                 goto ok_pgid;
1101                 } while_each_task_pid(rpgid, PIDTYPE_PGID, p);
1102                 goto out;
1103         }
1104
1105 ok_pgid:
1106         err = security_task_setpgid(p, rpgid);
1107         if (err)
1108                 goto out;
1109
1110         if (process_group(p) != rpgid) {
1111                 detach_pid(p, PIDTYPE_PGID);
1112                 p->signal->pgrp = rpgid;
1113                 attach_pid(p, PIDTYPE_PGID, rpgid);
1114         }
1115
1116         err = 0;
1117 out:
1118         /* All paths lead to here, thus we are safe. -DaveM */
1119         write_unlock_irq(&tasklist_lock);
1120         return err;
1121 }
1122
1123 asmlinkage long sys_getpgid(pid_t pid)
1124 {
1125         if (!pid) {
1126                 return vx_rmap_pid(process_group(current));
1127         } else {
1128                 int retval;
1129                 struct task_struct *p;
1130
1131                 read_lock(&tasklist_lock);
1132                 p = find_task_by_pid(pid);
1133
1134                 retval = -ESRCH;
1135                 if (p) {
1136                         retval = security_task_getpgid(p);
1137                         if (!retval)
1138                                 retval = vx_rmap_pid(process_group(p));
1139                 }
1140                 read_unlock(&tasklist_lock);
1141                 return retval;
1142         }
1143 }
1144
1145 #ifdef __ARCH_WANT_SYS_GETPGRP
1146
1147 asmlinkage long sys_getpgrp(void)
1148 {
1149         /* SMP - assuming writes are word atomic this is fine */
1150         return process_group(current);
1151 }
1152
1153 #endif
1154
1155 asmlinkage long sys_getsid(pid_t pid)
1156 {
1157         if (!pid) {
1158                 return current->signal->session;
1159         } else {
1160                 int retval;
1161                 struct task_struct *p;
1162
1163                 read_lock(&tasklist_lock);
1164                 p = find_task_by_pid(pid);
1165
1166                 retval = -ESRCH;
1167                 if(p) {
1168                         retval = security_task_getsid(p);
1169                         if (!retval)
1170                                 retval = p->signal->session;
1171                 }
1172                 read_unlock(&tasklist_lock);
1173                 return retval;
1174         }
1175 }
1176
1177 asmlinkage long sys_setsid(void)
1178 {
1179         struct pid *pid;
1180         int err = -EPERM;
1181
1182         if (!thread_group_leader(current))
1183                 return -EINVAL;
1184
1185         write_lock_irq(&tasklist_lock);
1186
1187         pid = find_pid(PIDTYPE_PGID, current->pid);
1188         if (pid)
1189                 goto out;
1190
1191         current->signal->leader = 1;
1192         __set_special_pids(current->pid, current->pid);
1193         current->signal->tty = NULL;
1194         current->signal->tty_old_pgrp = 0;
1195         err = process_group(current);
1196 out:
1197         write_unlock_irq(&tasklist_lock);
1198         return err;
1199 }
1200
1201 /*
1202  * Supplementary group IDs
1203  */
1204
1205 /* init to 2 - one for init_task, one to ensure it is never freed */
1206 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1207
1208 struct group_info *groups_alloc(int gidsetsize)
1209 {
1210         struct group_info *group_info;
1211         int nblocks;
1212         int i;
1213
1214         nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1215         /* Make sure we always allocate at least one indirect block pointer */
1216         nblocks = nblocks ? : 1;
1217         group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1218         if (!group_info)
1219                 return NULL;
1220         group_info->ngroups = gidsetsize;
1221         group_info->nblocks = nblocks;
1222         atomic_set(&group_info->usage, 1);
1223
1224         if (gidsetsize <= NGROUPS_SMALL) {
1225                 group_info->blocks[0] = group_info->small_block;
1226         } else {
1227                 for (i = 0; i < nblocks; i++) {
1228                         gid_t *b;
1229                         b = (void *)__get_free_page(GFP_USER);
1230                         if (!b)
1231                                 goto out_undo_partial_alloc;
1232                         group_info->blocks[i] = b;
1233                 }
1234         }
1235         return group_info;
1236
1237 out_undo_partial_alloc:
1238         while (--i >= 0) {
1239                 free_page((unsigned long)group_info->blocks[i]);
1240         }
1241         kfree(group_info);
1242         return NULL;
1243 }
1244
1245 EXPORT_SYMBOL(groups_alloc);
1246
1247 void groups_free(struct group_info *group_info)
1248 {
1249         if (group_info->blocks[0] != group_info->small_block) {
1250                 int i;
1251                 for (i = 0; i < group_info->nblocks; i++)
1252                         free_page((unsigned long)group_info->blocks[i]);
1253         }
1254         kfree(group_info);
1255 }
1256
1257 EXPORT_SYMBOL(groups_free);
1258
1259 /* export the group_info to a user-space array */
1260 static int groups_to_user(gid_t __user *grouplist,
1261     struct group_info *group_info)
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_to_user(grouplist+off, group_info->blocks[i], len))
1272                         return -EFAULT;
1273
1274                 count -= cp_count;
1275         }
1276         return 0;
1277 }
1278
1279 /* fill a group_info from a user-space array - it must be allocated already */
1280 static int groups_from_user(struct group_info *group_info,
1281     gid_t __user *grouplist)
1282  {
1283         int i;
1284         int count = group_info->ngroups;
1285
1286         for (i = 0; i < group_info->nblocks; i++) {
1287                 int cp_count = min(NGROUPS_PER_BLOCK, count);
1288                 int off = i * NGROUPS_PER_BLOCK;
1289                 int len = cp_count * sizeof(*grouplist);
1290
1291                 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1292                         return -EFAULT;
1293
1294                 count -= cp_count;
1295         }
1296         return 0;
1297 }
1298
1299 /* a simple shell-metzner sort */
1300 static void groups_sort(struct group_info *group_info)
1301 {
1302         int base, max, stride;
1303         int gidsetsize = group_info->ngroups;
1304
1305         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1306                 ; /* nothing */
1307         stride /= 3;
1308
1309         while (stride) {
1310                 max = gidsetsize - stride;
1311                 for (base = 0; base < max; base++) {
1312                         int left = base;
1313                         int right = left + stride;
1314                         gid_t tmp = GROUP_AT(group_info, right);
1315
1316                         while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1317                                 GROUP_AT(group_info, right) =
1318                                     GROUP_AT(group_info, left);
1319                                 right = left;
1320                                 left -= stride;
1321                         }
1322                         GROUP_AT(group_info, right) = tmp;
1323                 }
1324                 stride /= 3;
1325         }
1326 }
1327
1328 /* a simple bsearch */
1329 static int groups_search(struct group_info *group_info, gid_t grp)
1330 {
1331         int left, right;
1332
1333         if (!group_info)
1334                 return 0;
1335
1336         left = 0;
1337         right = group_info->ngroups;
1338         while (left < right) {
1339                 int mid = (left+right)/2;
1340                 int cmp = grp - GROUP_AT(group_info, mid);
1341                 if (cmp > 0)
1342                         left = mid + 1;
1343                 else if (cmp < 0)
1344                         right = mid;
1345                 else
1346                         return 1;
1347         }
1348         return 0;
1349 }
1350
1351 /* validate and set current->group_info */
1352 int set_current_groups(struct group_info *group_info)
1353 {
1354         int retval;
1355         struct group_info *old_info;
1356
1357         retval = security_task_setgroups(group_info);
1358         if (retval)
1359                 return retval;
1360
1361         groups_sort(group_info);
1362         get_group_info(group_info);
1363
1364         task_lock(current);
1365         old_info = current->group_info;
1366         current->group_info = group_info;
1367         task_unlock(current);
1368
1369         put_group_info(old_info);
1370
1371         return 0;
1372 }
1373
1374 EXPORT_SYMBOL(set_current_groups);
1375
1376 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1377 {
1378         int i = 0;
1379
1380         /*
1381          *      SMP: Nobody else can change our grouplist. Thus we are
1382          *      safe.
1383          */
1384
1385         if (gidsetsize < 0)
1386                 return -EINVAL;
1387
1388         /* no need to grab task_lock here; it cannot change */
1389         get_group_info(current->group_info);
1390         i = current->group_info->ngroups;
1391         if (gidsetsize) {
1392                 if (i > gidsetsize) {
1393                         i = -EINVAL;
1394                         goto out;
1395                 }
1396                 if (groups_to_user(grouplist, current->group_info)) {
1397                         i = -EFAULT;
1398                         goto out;
1399                 }
1400         }
1401 out:
1402         put_group_info(current->group_info);
1403         return i;
1404 }
1405
1406 /*
1407  *      SMP: Our groups are copy-on-write. We can set them safely
1408  *      without another task interfering.
1409  */
1410
1411 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1412 {
1413         struct group_info *group_info;
1414         int retval;
1415
1416         if (!capable(CAP_SETGID))
1417                 return -EPERM;
1418         if ((unsigned)gidsetsize > NGROUPS_MAX)
1419                 return -EINVAL;
1420
1421         group_info = groups_alloc(gidsetsize);
1422         if (!group_info)
1423                 return -ENOMEM;
1424         retval = groups_from_user(group_info, grouplist);
1425         if (retval) {
1426                 put_group_info(group_info);
1427                 return retval;
1428         }
1429
1430         retval = set_current_groups(group_info);
1431         put_group_info(group_info);
1432
1433         return retval;
1434 }
1435
1436 /*
1437  * Check whether we're fsgid/egid or in the supplemental group..
1438  */
1439 int in_group_p(gid_t grp)
1440 {
1441         int retval = 1;
1442         if (grp != current->fsgid) {
1443                 get_group_info(current->group_info);
1444                 retval = groups_search(current->group_info, grp);
1445                 put_group_info(current->group_info);
1446         }
1447         return retval;
1448 }
1449
1450 EXPORT_SYMBOL(in_group_p);
1451
1452 int in_egroup_p(gid_t grp)
1453 {
1454         int retval = 1;
1455         if (grp != current->egid) {
1456                 get_group_info(current->group_info);
1457                 retval = groups_search(current->group_info, grp);
1458                 put_group_info(current->group_info);
1459         }
1460         return retval;
1461 }
1462
1463 EXPORT_SYMBOL(in_egroup_p);
1464
1465 DECLARE_RWSEM(uts_sem);
1466
1467 EXPORT_SYMBOL(uts_sem);
1468
1469 asmlinkage long sys_newuname(struct new_utsname __user * name)
1470 {
1471         int errno = 0;
1472
1473         down_read(&uts_sem);
1474         if (copy_to_user(name, vx_new_utsname(), sizeof *name))
1475                 errno = -EFAULT;
1476         up_read(&uts_sem);
1477         return errno;
1478 }
1479
1480 asmlinkage long sys_sethostname(char __user *name, int len)
1481 {
1482         int errno;
1483         char tmp[__NEW_UTS_LEN];
1484
1485         if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SET_UTSNAME))
1486                 return -EPERM;
1487         if (len < 0 || len > __NEW_UTS_LEN)
1488                 return -EINVAL;
1489         down_write(&uts_sem);
1490         errno = -EFAULT;
1491         if (!copy_from_user(tmp, name, len)) {
1492                 char *ptr = vx_new_uts(nodename);
1493
1494                 memcpy(ptr, tmp, len);
1495                 ptr[len] = 0;
1496                 errno = 0;
1497         }
1498         up_write(&uts_sem);
1499         return errno;
1500 }
1501
1502 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1503
1504 asmlinkage long sys_gethostname(char __user *name, int len)
1505 {
1506         int i, errno;
1507         char *ptr;
1508
1509         if (len < 0)
1510                 return -EINVAL;
1511         down_read(&uts_sem);
1512         ptr = vx_new_uts(nodename);
1513         i = 1 + strlen(ptr);
1514         if (i > len)
1515                 i = len;
1516         errno = 0;
1517         if (copy_to_user(name, ptr, i))
1518                 errno = -EFAULT;
1519         up_read(&uts_sem);
1520         return errno;
1521 }
1522
1523 #endif
1524
1525 /*
1526  * Only setdomainname; getdomainname can be implemented by calling
1527  * uname()
1528  */
1529 asmlinkage long sys_setdomainname(char __user *name, int len)
1530 {
1531         int errno;
1532         char tmp[__NEW_UTS_LEN];
1533
1534         if (!capable(CAP_SYS_ADMIN) && !vx_ccaps(VXC_SET_UTSNAME))
1535                 return -EPERM;
1536         if (len < 0 || len > __NEW_UTS_LEN)
1537                 return -EINVAL;
1538
1539         down_write(&uts_sem);
1540         errno = -EFAULT;
1541         if (!copy_from_user(tmp, name, len)) {
1542                 char *ptr = vx_new_uts(domainname);
1543
1544                 memcpy(ptr, tmp, len);
1545                 ptr[len] = 0;
1546                 errno = 0;
1547         }
1548         up_write(&uts_sem);
1549         return errno;
1550 }
1551
1552 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1553 {
1554         if (resource >= RLIM_NLIMITS)
1555                 return -EINVAL;
1556         else
1557                 return copy_to_user(rlim, current->rlim + resource, sizeof(*rlim))
1558                         ? -EFAULT : 0;
1559 }
1560
1561 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1562
1563 /*
1564  *      Back compatibility for getrlimit. Needed for some apps.
1565  */
1566
1567 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1568 {
1569         struct rlimit x;
1570         if (resource >= RLIM_NLIMITS)
1571                 return -EINVAL;
1572
1573         memcpy(&x, current->rlim + resource, sizeof(*rlim));
1574         if(x.rlim_cur > 0x7FFFFFFF)
1575                 x.rlim_cur = 0x7FFFFFFF;
1576         if(x.rlim_max > 0x7FFFFFFF)
1577                 x.rlim_max = 0x7FFFFFFF;
1578         return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1579 }
1580
1581 #endif
1582
1583 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1584 {
1585         struct rlimit new_rlim, *old_rlim;
1586         int retval;
1587
1588         if (resource >= RLIM_NLIMITS)
1589                 return -EINVAL;
1590         if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1591                 return -EFAULT;
1592        if (new_rlim.rlim_cur > new_rlim.rlim_max)
1593                return -EINVAL;
1594         old_rlim = current->rlim + resource;
1595         if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
1596              (new_rlim.rlim_max > old_rlim->rlim_max)) &&
1597             !capable(CAP_SYS_RESOURCE) && !vx_ccaps(VXC_SET_RLIMIT))
1598                 return -EPERM;
1599         if (resource == RLIMIT_NOFILE) {
1600                 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
1601                         return -EPERM;
1602         }
1603
1604         retval = security_task_setrlimit(resource, &new_rlim);
1605         if (retval)
1606                 return retval;
1607
1608         *old_rlim = new_rlim;
1609         return 0;
1610 }
1611
1612 /*
1613  * It would make sense to put struct rusage in the task_struct,
1614  * except that would make the task_struct be *really big*.  After
1615  * task_struct gets moved into malloc'ed memory, it would
1616  * make sense to do this.  It will make moving the rest of the information
1617  * a lot simpler!  (Which we're not doing right now because we're not
1618  * measuring them yet).
1619  *
1620  * This expects to be called with tasklist_lock read-locked or better,
1621  * and the siglock not locked.  It may momentarily take the siglock.
1622  *
1623  * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1624  * races with threads incrementing their own counters.  But since word
1625  * reads are atomic, we either get new values or old values and we don't
1626  * care which for the sums.  We always take the siglock to protect reading
1627  * the c* fields from p->signal from races with exit.c updating those
1628  * fields when reaping, so a sample either gets all the additions of a
1629  * given child after it's reaped, or none so this sample is before reaping.
1630  */
1631
1632 void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1633 {
1634         struct task_struct *t;
1635         unsigned long flags;
1636         unsigned long utime, stime;
1637
1638         memset((char *) r, 0, sizeof *r);
1639
1640         if (unlikely(!p->signal))
1641                 return;
1642
1643         switch (who) {
1644                 case RUSAGE_CHILDREN:
1645                         spin_lock_irqsave(&p->sighand->siglock, flags);
1646                         utime = p->signal->cutime;
1647                         stime = p->signal->cstime;
1648                         r->ru_nvcsw = p->signal->cnvcsw;
1649                         r->ru_nivcsw = p->signal->cnivcsw;
1650                         r->ru_minflt = p->signal->cmin_flt;
1651                         r->ru_majflt = p->signal->cmaj_flt;
1652                         spin_unlock_irqrestore(&p->sighand->siglock, flags);
1653                         jiffies_to_timeval(utime, &r->ru_utime);
1654                         jiffies_to_timeval(stime, &r->ru_stime);
1655                         break;
1656                 case RUSAGE_SELF:
1657                         spin_lock_irqsave(&p->sighand->siglock, flags);
1658                         utime = stime = 0;
1659                         goto sum_group;
1660                 case RUSAGE_BOTH:
1661                         spin_lock_irqsave(&p->sighand->siglock, flags);
1662                         utime = p->signal->cutime;
1663                         stime = p->signal->cstime;
1664                         r->ru_nvcsw = p->signal->cnvcsw;
1665                         r->ru_nivcsw = p->signal->cnivcsw;
1666                         r->ru_minflt = p->signal->cmin_flt;
1667                         r->ru_majflt = p->signal->cmaj_flt;
1668                 sum_group:
1669                         utime += p->signal->utime;
1670                         stime += p->signal->stime;
1671                         r->ru_nvcsw += p->signal->nvcsw;
1672                         r->ru_nivcsw += p->signal->nivcsw;
1673                         r->ru_minflt += p->signal->min_flt;
1674                         r->ru_majflt += p->signal->maj_flt;
1675                         t = p;
1676                         do {
1677                                 utime += t->utime;
1678                                 stime += t->stime;
1679                                 r->ru_nvcsw += t->nvcsw;
1680                                 r->ru_nivcsw += t->nivcsw;
1681                                 r->ru_minflt += t->min_flt;
1682                                 r->ru_majflt += t->maj_flt;
1683                                 t = next_thread(t);
1684                         } while (t != p);
1685                         spin_unlock_irqrestore(&p->sighand->siglock, flags);
1686                         jiffies_to_timeval(utime, &r->ru_utime);
1687                         jiffies_to_timeval(stime, &r->ru_stime);
1688                         break;
1689                 default:
1690                         BUG();
1691         }
1692 }
1693
1694 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1695 {
1696         struct rusage r;
1697         read_lock(&tasklist_lock);
1698         k_getrusage(p, who, &r);
1699         read_unlock(&tasklist_lock);
1700         return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1701 }
1702
1703 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1704 {
1705         if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1706                 return -EINVAL;
1707         return getrusage(current, who, ru);
1708 }
1709
1710 asmlinkage long sys_umask(int mask)
1711 {
1712         mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1713         return mask;
1714 }
1715
1716 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1717                           unsigned long arg4, unsigned long arg5)
1718 {
1719         int error;
1720         int sig;
1721
1722         error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1723         if (error)
1724                 return error;
1725
1726         switch (option) {
1727                 case PR_SET_PDEATHSIG:
1728                         sig = arg2;
1729                         if (sig < 0 || sig > _NSIG) {
1730                                 error = -EINVAL;
1731                                 break;
1732                         }
1733                         current->pdeath_signal = sig;
1734                         break;
1735                 case PR_GET_PDEATHSIG:
1736                         error = put_user(current->pdeath_signal, (int __user *)arg2);
1737                         break;
1738                 case PR_GET_DUMPABLE:
1739                         if (current->mm->dumpable)
1740                                 error = 1;
1741                         break;
1742                 case PR_SET_DUMPABLE:
1743                         if (arg2 < 0 || arg2 > 2) {
1744                                 error = -EINVAL;
1745                                 break;
1746                         }
1747                         current->mm->dumpable = arg2;
1748                         break;
1749
1750                 case PR_SET_UNALIGN:
1751                         error = SET_UNALIGN_CTL(current, arg2);
1752                         break;
1753                 case PR_GET_UNALIGN:
1754                         error = GET_UNALIGN_CTL(current, arg2);
1755                         break;
1756                 case PR_SET_FPEMU:
1757                         error = SET_FPEMU_CTL(current, arg2);
1758                         break;
1759                 case PR_GET_FPEMU:
1760                         error = GET_FPEMU_CTL(current, arg2);
1761                         break;
1762                 case PR_SET_FPEXC:
1763                         error = SET_FPEXC_CTL(current, arg2);
1764                         break;
1765                 case PR_GET_FPEXC:
1766                         error = GET_FPEXC_CTL(current, arg2);
1767                         break;
1768                 case PR_GET_TIMING:
1769                         error = PR_TIMING_STATISTICAL;
1770                         break;
1771                 case PR_SET_TIMING:
1772                         if (arg2 == PR_TIMING_STATISTICAL)
1773                                 error = 0;
1774                         else
1775                                 error = -EINVAL;
1776                         break;
1777
1778                 case PR_GET_KEEPCAPS:
1779                         if (current->keep_capabilities)
1780                                 error = 1;
1781                         break;
1782                 case PR_SET_KEEPCAPS:
1783                         if (arg2 != 0 && arg2 != 1) {
1784                                 error = -EINVAL;
1785                                 break;
1786                         }
1787                         current->keep_capabilities = arg2;
1788                         break;
1789                 case PR_SET_NAME: {
1790                         struct task_struct *me = current;
1791                         unsigned char ncomm[sizeof(me->comm)];
1792
1793                         ncomm[sizeof(me->comm)-1] = 0;
1794                         if (strncpy_from_user(ncomm, (char __user *)arg2,
1795                                                 sizeof(me->comm)-1) < 0)
1796                                 return -EFAULT;
1797                         set_task_comm(me, ncomm);
1798                         return 0;
1799                 }
1800                 default:
1801                         error = -EINVAL;
1802                         break;
1803         }
1804         return error;
1805 }