linux/kernel/sys.c
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   1/*
   2 *  linux/kernel/sys.c
   3 *
   4 *  Copyright (C) 1991, 1992  Linus Torvalds
   5 */
   6
   7#include <linux/export.h>
   8#include <linux/mm.h>
   9#include <linux/utsname.h>
  10#include <linux/mman.h>
  11#include <linux/reboot.h>
  12#include <linux/prctl.h>
  13#include <linux/highuid.h>
  14#include <linux/fs.h>
  15#include <linux/kmod.h>
  16#include <linux/perf_event.h>
  17#include <linux/resource.h>
  18#include <linux/kernel.h>
  19#include <linux/kexec.h>
  20#include <linux/workqueue.h>
  21#include <linux/capability.h>
  22#include <linux/device.h>
  23#include <linux/key.h>
  24#include <linux/times.h>
  25#include <linux/posix-timers.h>
  26#include <linux/security.h>
  27#include <linux/dcookies.h>
  28#include <linux/suspend.h>
  29#include <linux/tty.h>
  30#include <linux/signal.h>
  31#include <linux/cn_proc.h>
  32#include <linux/getcpu.h>
  33#include <linux/task_io_accounting_ops.h>
  34#include <linux/seccomp.h>
  35#include <linux/cpu.h>
  36#include <linux/personality.h>
  37#include <linux/ptrace.h>
  38#include <linux/fs_struct.h>
  39#include <linux/file.h>
  40#include <linux/mount.h>
  41#include <linux/gfp.h>
  42#include <linux/syscore_ops.h>
  43#include <linux/version.h>
  44#include <linux/ctype.h>
  45
  46#include <linux/compat.h>
  47#include <linux/syscalls.h>
  48#include <linux/kprobes.h>
  49#include <linux/user_namespace.h>
  50#include <linux/binfmts.h>
  51
  52#include <linux/sched.h>
  53#include <linux/rcupdate.h>
  54#include <linux/uidgid.h>
  55#include <linux/cred.h>
  56
  57#include <linux/kmsg_dump.h>
  58/* Move somewhere else to avoid recompiling? */
  59#include <generated/utsrelease.h>
  60
  61#include <asm/uaccess.h>
  62#include <asm/io.h>
  63#include <asm/unistd.h>
  64
  65#ifndef SET_UNALIGN_CTL
  66# define SET_UNALIGN_CTL(a,b)   (-EINVAL)
  67#endif
  68#ifndef GET_UNALIGN_CTL
  69# define GET_UNALIGN_CTL(a,b)   (-EINVAL)
  70#endif
  71#ifndef SET_FPEMU_CTL
  72# define SET_FPEMU_CTL(a,b)     (-EINVAL)
  73#endif
  74#ifndef GET_FPEMU_CTL
  75# define GET_FPEMU_CTL(a,b)     (-EINVAL)
  76#endif
  77#ifndef SET_FPEXC_CTL
  78# define SET_FPEXC_CTL(a,b)     (-EINVAL)
  79#endif
  80#ifndef GET_FPEXC_CTL
  81# define GET_FPEXC_CTL(a,b)     (-EINVAL)
  82#endif
  83#ifndef GET_ENDIAN
  84# define GET_ENDIAN(a,b)        (-EINVAL)
  85#endif
  86#ifndef SET_ENDIAN
  87# define SET_ENDIAN(a,b)        (-EINVAL)
  88#endif
  89#ifndef GET_TSC_CTL
  90# define GET_TSC_CTL(a)         (-EINVAL)
  91#endif
  92#ifndef SET_TSC_CTL
  93# define SET_TSC_CTL(a)         (-EINVAL)
  94#endif
  95
  96/*
  97 * this is where the system-wide overflow UID and GID are defined, for
  98 * architectures that now have 32-bit UID/GID but didn't in the past
  99 */
 100
 101int overflowuid = DEFAULT_OVERFLOWUID;
 102int overflowgid = DEFAULT_OVERFLOWGID;
 103
 104EXPORT_SYMBOL(overflowuid);
 105EXPORT_SYMBOL(overflowgid);
 106
 107/*
 108 * the same as above, but for filesystems which can only store a 16-bit
 109 * UID and GID. as such, this is needed on all architectures
 110 */
 111
 112int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
 113int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
 114
 115EXPORT_SYMBOL(fs_overflowuid);
 116EXPORT_SYMBOL(fs_overflowgid);
 117
 118/*
 119 * Returns true if current's euid is same as p's uid or euid,
 120 * or has CAP_SYS_NICE to p's user_ns.
 121 *
 122 * Called with rcu_read_lock, creds are safe
 123 */
 124static bool set_one_prio_perm(struct task_struct *p)
 125{
 126        const struct cred *cred = current_cred(), *pcred = __task_cred(p);
 127
 128        if (uid_eq(pcred->uid,  cred->euid) ||
 129            uid_eq(pcred->euid, cred->euid))
 130                return true;
 131        if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
 132                return true;
 133        return false;
 134}
 135
 136/*
 137 * set the priority of a task
 138 * - the caller must hold the RCU read lock
 139 */
 140static int set_one_prio(struct task_struct *p, int niceval, int error)
 141{
 142        int no_nice;
 143
 144        if (!set_one_prio_perm(p)) {
 145                error = -EPERM;
 146                goto out;
 147        }
 148        if (niceval < task_nice(p) && !can_nice(p, niceval)) {
 149                error = -EACCES;
 150                goto out;
 151        }
 152        no_nice = security_task_setnice(p, niceval);
 153        if (no_nice) {
 154                error = no_nice;
 155                goto out;
 156        }
 157        if (error == -ESRCH)
 158                error = 0;
 159        set_user_nice(p, niceval);
 160out:
 161        return error;
 162}
 163
 164SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
 165{
 166        struct task_struct *g, *p;
 167        struct user_struct *user;
 168        const struct cred *cred = current_cred();
 169        int error = -EINVAL;
 170        struct pid *pgrp;
 171        kuid_t uid;
 172
 173        if (which > PRIO_USER || which < PRIO_PROCESS)
 174                goto out;
 175
 176        /* normalize: avoid signed division (rounding problems) */
 177        error = -ESRCH;
 178        if (niceval < -20)
 179                niceval = -20;
 180        if (niceval > 19)
 181                niceval = 19;
 182
 183        rcu_read_lock();
 184        read_lock(&tasklist_lock);
 185        switch (which) {
 186                case PRIO_PROCESS:
 187                        if (who)
 188                                p = find_task_by_vpid(who);
 189                        else
 190                                p = current;
 191                        if (p)
 192                                error = set_one_prio(p, niceval, error);
 193                        break;
 194                case PRIO_PGRP:
 195                        if (who)
 196                                pgrp = find_vpid(who);
 197                        else
 198                                pgrp = task_pgrp(current);
 199                        do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 200                                error = set_one_prio(p, niceval, error);
 201                        } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 202                        break;
 203                case PRIO_USER:
 204                        uid = make_kuid(cred->user_ns, who);
 205                        user = cred->user;
 206                        if (!who)
 207                                uid = cred->uid;
 208                        else if (!uid_eq(uid, cred->uid) &&
 209                                 !(user = find_user(uid)))
 210                                goto out_unlock;        /* No processes for this user */
 211
 212                        do_each_thread(g, p) {
 213                                if (uid_eq(task_uid(p), uid))
 214                                        error = set_one_prio(p, niceval, error);
 215                        } while_each_thread(g, p);
 216                        if (!uid_eq(uid, cred->uid))
 217                                free_uid(user);         /* For find_user() */
 218                        break;
 219        }
 220out_unlock:
 221        read_unlock(&tasklist_lock);
 222        rcu_read_unlock();
 223out:
 224        return error;
 225}
 226
 227/*
 228 * Ugh. To avoid negative return values, "getpriority()" will
 229 * not return the normal nice-value, but a negated value that
 230 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 231 * to stay compatible.
 232 */
 233SYSCALL_DEFINE2(getpriority, int, which, int, who)
 234{
 235        struct task_struct *g, *p;
 236        struct user_struct *user;
 237        const struct cred *cred = current_cred();
 238        long niceval, retval = -ESRCH;
 239        struct pid *pgrp;
 240        kuid_t uid;
 241
 242        if (which > PRIO_USER || which < PRIO_PROCESS)
 243                return -EINVAL;
 244
 245        rcu_read_lock();
 246        read_lock(&tasklist_lock);
 247        switch (which) {
 248                case PRIO_PROCESS:
 249                        if (who)
 250                                p = find_task_by_vpid(who);
 251                        else
 252                                p = current;
 253                        if (p) {
 254                                niceval = 20 - task_nice(p);
 255                                if (niceval > retval)
 256                                        retval = niceval;
 257                        }
 258                        break;
 259                case PRIO_PGRP:
 260                        if (who)
 261                                pgrp = find_vpid(who);
 262                        else
 263                                pgrp = task_pgrp(current);
 264                        do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 265                                niceval = 20 - task_nice(p);
 266                                if (niceval > retval)
 267                                        retval = niceval;
 268                        } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 269                        break;
 270                case PRIO_USER:
 271                        uid = make_kuid(cred->user_ns, who);
 272                        user = cred->user;
 273                        if (!who)
 274                                uid = cred->uid;
 275                        else if (!uid_eq(uid, cred->uid) &&
 276                                 !(user = find_user(uid)))
 277                                goto out_unlock;        /* No processes for this user */
 278
 279                        do_each_thread(g, p) {
 280                                if (uid_eq(task_uid(p), uid)) {
 281                                        niceval = 20 - task_nice(p);
 282                                        if (niceval > retval)
 283                                                retval = niceval;
 284                                }
 285                        } while_each_thread(g, p);
 286                        if (!uid_eq(uid, cred->uid))
 287                                free_uid(user);         /* for find_user() */
 288                        break;
 289        }
 290out_unlock:
 291        read_unlock(&tasklist_lock);
 292        rcu_read_unlock();
 293
 294        return retval;
 295}
 296
 297/*
 298 * Unprivileged users may change the real gid to the effective gid
 299 * or vice versa.  (BSD-style)
 300 *
 301 * If you set the real gid at all, or set the effective gid to a value not
 302 * equal to the real gid, then the saved gid is set to the new effective gid.
 303 *
 304 * This makes it possible for a setgid program to completely drop its
 305 * privileges, which is often a useful assertion to make when you are doing
 306 * a security audit over a program.
 307 *
 308 * The general idea is that a program which uses just setregid() will be
 309 * 100% compatible with BSD.  A program which uses just setgid() will be
 310 * 100% compatible with POSIX with saved IDs. 
 311 *
 312 * SMP: There are not races, the GIDs are checked only by filesystem
 313 *      operations (as far as semantic preservation is concerned).
 314 */
 315SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
 316{
 317        struct user_namespace *ns = current_user_ns();
 318        const struct cred *old;
 319        struct cred *new;
 320        int retval;
 321        kgid_t krgid, kegid;
 322
 323        krgid = make_kgid(ns, rgid);
 324        kegid = make_kgid(ns, egid);
 325
 326        if ((rgid != (gid_t) -1) && !gid_valid(krgid))
 327                return -EINVAL;
 328        if ((egid != (gid_t) -1) && !gid_valid(kegid))
 329                return -EINVAL;
 330
 331        new = prepare_creds();
 332        if (!new)
 333                return -ENOMEM;
 334        old = current_cred();
 335
 336        retval = -EPERM;
 337        if (rgid != (gid_t) -1) {
 338                if (gid_eq(old->gid, krgid) ||
 339                    gid_eq(old->egid, krgid) ||
 340                    ns_capable(old->user_ns, CAP_SETGID))
 341                        new->gid = krgid;
 342                else
 343                        goto error;
 344        }
 345        if (egid != (gid_t) -1) {
 346                if (gid_eq(old->gid, kegid) ||
 347                    gid_eq(old->egid, kegid) ||
 348                    gid_eq(old->sgid, kegid) ||
 349                    ns_capable(old->user_ns, CAP_SETGID))
 350                        new->egid = kegid;
 351                else
 352                        goto error;
 353        }
 354
 355        if (rgid != (gid_t) -1 ||
 356            (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
 357                new->sgid = new->egid;
 358        new->fsgid = new->egid;
 359
 360        return commit_creds(new);
 361
 362error:
 363        abort_creds(new);
 364        return retval;
 365}
 366
 367/*
 368 * setgid() is implemented like SysV w/ SAVED_IDS 
 369 *
 370 * SMP: Same implicit races as above.
 371 */
 372SYSCALL_DEFINE1(setgid, gid_t, gid)
 373{
 374        struct user_namespace *ns = current_user_ns();
 375        const struct cred *old;
 376        struct cred *new;
 377        int retval;
 378        kgid_t kgid;
 379
 380        kgid = make_kgid(ns, gid);
 381        if (!gid_valid(kgid))
 382                return -EINVAL;
 383
 384        new = prepare_creds();
 385        if (!new)
 386                return -ENOMEM;
 387        old = current_cred();
 388
 389        retval = -EPERM;
 390        if (ns_capable(old->user_ns, CAP_SETGID))
 391                new->gid = new->egid = new->sgid = new->fsgid = kgid;
 392        else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
 393                new->egid = new->fsgid = kgid;
 394        else
 395                goto error;
 396
 397        return commit_creds(new);
 398
 399error:
 400        abort_creds(new);
 401        return retval;
 402}
 403
 404/*
 405 * change the user struct in a credentials set to match the new UID
 406 */
 407static int set_user(struct cred *new)
 408{
 409        struct user_struct *new_user;
 410
 411        new_user = alloc_uid(new->uid);
 412        if (!new_user)
 413                return -EAGAIN;
 414
 415        /*
 416         * We don't fail in case of NPROC limit excess here because too many
 417         * poorly written programs don't check set*uid() return code, assuming
 418         * it never fails if called by root.  We may still enforce NPROC limit
 419         * for programs doing set*uid()+execve() by harmlessly deferring the
 420         * failure to the execve() stage.
 421         */
 422        if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
 423                        new_user != INIT_USER)
 424                current->flags |= PF_NPROC_EXCEEDED;
 425        else
 426                current->flags &= ~PF_NPROC_EXCEEDED;
 427
 428        free_uid(new->user);
 429        new->user = new_user;
 430        return 0;
 431}
 432
 433/*
 434 * Unprivileged users may change the real uid to the effective uid
 435 * or vice versa.  (BSD-style)
 436 *
 437 * If you set the real uid at all, or set the effective uid to a value not
 438 * equal to the real uid, then the saved uid is set to the new effective uid.
 439 *
 440 * This makes it possible for a setuid program to completely drop its
 441 * privileges, which is often a useful assertion to make when you are doing
 442 * a security audit over a program.
 443 *
 444 * The general idea is that a program which uses just setreuid() will be
 445 * 100% compatible with BSD.  A program which uses just setuid() will be
 446 * 100% compatible with POSIX with saved IDs. 
 447 */
 448SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
 449{
 450        struct user_namespace *ns = current_user_ns();
 451        const struct cred *old;
 452        struct cred *new;
 453        int retval;
 454        kuid_t kruid, keuid;
 455
 456        kruid = make_kuid(ns, ruid);
 457        keuid = make_kuid(ns, euid);
 458
 459        if ((ruid != (uid_t) -1) && !uid_valid(kruid))
 460                return -EINVAL;
 461        if ((euid != (uid_t) -1) && !uid_valid(keuid))
 462                return -EINVAL;
 463
 464        new = prepare_creds();
 465        if (!new)
 466                return -ENOMEM;
 467        old = current_cred();
 468
 469        retval = -EPERM;
 470        if (ruid != (uid_t) -1) {
 471                new->uid = kruid;
 472                if (!uid_eq(old->uid, kruid) &&
 473                    !uid_eq(old->euid, kruid) &&
 474                    !ns_capable(old->user_ns, CAP_SETUID))
 475                        goto error;
 476        }
 477
 478        if (euid != (uid_t) -1) {
 479                new->euid = keuid;
 480                if (!uid_eq(old->uid, keuid) &&
 481                    !uid_eq(old->euid, keuid) &&
 482                    !uid_eq(old->suid, keuid) &&
 483                    !ns_capable(old->user_ns, CAP_SETUID))
 484                        goto error;
 485        }
 486
 487        if (!uid_eq(new->uid, old->uid)) {
 488                retval = set_user(new);
 489                if (retval < 0)
 490                        goto error;
 491        }
 492        if (ruid != (uid_t) -1 ||
 493            (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
 494                new->suid = new->euid;
 495        new->fsuid = new->euid;
 496
 497        retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
 498        if (retval < 0)
 499                goto error;
 500
 501        return commit_creds(new);
 502
 503error:
 504        abort_creds(new);
 505        return retval;
 506}
 507                
 508/*
 509 * setuid() is implemented like SysV with SAVED_IDS 
 510 * 
 511 * Note that SAVED_ID's is deficient in that a setuid root program
 512 * like sendmail, for example, cannot set its uid to be a normal 
 513 * user and then switch back, because if you're root, setuid() sets
 514 * the saved uid too.  If you don't like this, blame the bright people
 515 * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 516 * will allow a root program to temporarily drop privileges and be able to
 517 * regain them by swapping the real and effective uid.  
 518 */
 519SYSCALL_DEFINE1(setuid, uid_t, uid)
 520{
 521        struct user_namespace *ns = current_user_ns();
 522        const struct cred *old;
 523        struct cred *new;
 524        int retval;
 525        kuid_t kuid;
 526
 527        kuid = make_kuid(ns, uid);
 528        if (!uid_valid(kuid))
 529                return -EINVAL;
 530
 531        new = prepare_creds();
 532        if (!new)
 533                return -ENOMEM;
 534        old = current_cred();
 535
 536        retval = -EPERM;
 537        if (ns_capable(old->user_ns, CAP_SETUID)) {
 538                new->suid = new->uid = kuid;
 539                if (!uid_eq(kuid, old->uid)) {
 540                        retval = set_user(new);
 541                        if (retval < 0)
 542                                goto error;
 543                }
 544        } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
 545                goto error;
 546        }
 547
 548        new->fsuid = new->euid = kuid;
 549
 550        retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
 551        if (retval < 0)
 552                goto error;
 553
 554        return commit_creds(new);
 555
 556error:
 557        abort_creds(new);
 558        return retval;
 559}
 560
 561
 562/*
 563 * This function implements a generic ability to update ruid, euid,
 564 * and suid.  This allows you to implement the 4.4 compatible seteuid().
 565 */
 566SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
 567{
 568        struct user_namespace *ns = current_user_ns();
 569        const struct cred *old;
 570        struct cred *new;
 571        int retval;
 572        kuid_t kruid, keuid, ksuid;
 573
 574        kruid = make_kuid(ns, ruid);
 575        keuid = make_kuid(ns, euid);
 576        ksuid = make_kuid(ns, suid);
 577
 578        if ((ruid != (uid_t) -1) && !uid_valid(kruid))
 579                return -EINVAL;
 580
 581        if ((euid != (uid_t) -1) && !uid_valid(keuid))
 582                return -EINVAL;
 583
 584        if ((suid != (uid_t) -1) && !uid_valid(ksuid))
 585                return -EINVAL;
 586
 587        new = prepare_creds();
 588        if (!new)
 589                return -ENOMEM;
 590
 591        old = current_cred();
 592
 593        retval = -EPERM;
 594        if (!ns_capable(old->user_ns, CAP_SETUID)) {
 595                if (ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
 596                    !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
 597                        goto error;
 598                if (euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
 599                    !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
 600                        goto error;
 601                if (suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
 602                    !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
 603                        goto error;
 604        }
 605
 606        if (ruid != (uid_t) -1) {
 607                new->uid = kruid;
 608                if (!uid_eq(kruid, old->uid)) {
 609                        retval = set_user(new);
 610                        if (retval < 0)
 611                                goto error;
 612                }
 613        }
 614        if (euid != (uid_t) -1)
 615                new->euid = keuid;
 616        if (suid != (uid_t) -1)
 617                new->suid = ksuid;
 618        new->fsuid = new->euid;
 619
 620        retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
 621        if (retval < 0)
 622                goto error;
 623
 624        return commit_creds(new);
 625
 626error:
 627        abort_creds(new);
 628        return retval;
 629}
 630
 631SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
 632{
 633        const struct cred *cred = current_cred();
 634        int retval;
 635        uid_t ruid, euid, suid;
 636
 637        ruid = from_kuid_munged(cred->user_ns, cred->uid);
 638        euid = from_kuid_munged(cred->user_ns, cred->euid);
 639        suid = from_kuid_munged(cred->user_ns, cred->suid);
 640
 641        if (!(retval   = put_user(ruid, ruidp)) &&
 642            !(retval   = put_user(euid, euidp)))
 643                retval = put_user(suid, suidp);
 644
 645        return retval;
 646}
 647
 648/*
 649 * Same as above, but for rgid, egid, sgid.
 650 */
 651SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
 652{
 653        struct user_namespace *ns = current_user_ns();
 654        const struct cred *old;
 655        struct cred *new;
 656        int retval;
 657        kgid_t krgid, kegid, ksgid;
 658
 659        krgid = make_kgid(ns, rgid);
 660        kegid = make_kgid(ns, egid);
 661        ksgid = make_kgid(ns, sgid);
 662
 663        if ((rgid != (gid_t) -1) && !gid_valid(krgid))
 664                return -EINVAL;
 665        if ((egid != (gid_t) -1) && !gid_valid(kegid))
 666                return -EINVAL;
 667        if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
 668                return -EINVAL;
 669
 670        new = prepare_creds();
 671        if (!new)
 672                return -ENOMEM;
 673        old = current_cred();
 674
 675        retval = -EPERM;
 676        if (!ns_capable(old->user_ns, CAP_SETGID)) {
 677                if (rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
 678                    !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
 679                        goto error;
 680                if (egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
 681                    !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
 682                        goto error;
 683                if (sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
 684                    !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
 685                        goto error;
 686        }
 687
 688        if (rgid != (gid_t) -1)
 689                new->gid = krgid;
 690        if (egid != (gid_t) -1)
 691                new->egid = kegid;
 692        if (sgid != (gid_t) -1)
 693                new->sgid = ksgid;
 694        new->fsgid = new->egid;
 695
 696        return commit_creds(new);
 697
 698error:
 699        abort_creds(new);
 700        return retval;
 701}
 702
 703SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
 704{
 705        const struct cred *cred = current_cred();
 706        int retval;
 707        gid_t rgid, egid, sgid;
 708
 709        rgid = from_kgid_munged(cred->user_ns, cred->gid);
 710        egid = from_kgid_munged(cred->user_ns, cred->egid);
 711        sgid = from_kgid_munged(cred->user_ns, cred->sgid);
 712
 713        if (!(retval   = put_user(rgid, rgidp)) &&
 714            !(retval   = put_user(egid, egidp)))
 715                retval = put_user(sgid, sgidp);
 716
 717        return retval;
 718}
 719
 720
 721/*
 722 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 723 * is used for "access()" and for the NFS daemon (letting nfsd stay at
 724 * whatever uid it wants to). It normally shadows "euid", except when
 725 * explicitly set by setfsuid() or for access..
 726 */
 727SYSCALL_DEFINE1(setfsuid, uid_t, uid)
 728{
 729        const struct cred *old;
 730        struct cred *new;
 731        uid_t old_fsuid;
 732        kuid_t kuid;
 733
 734        old = current_cred();
 735        old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
 736
 737        kuid = make_kuid(old->user_ns, uid);
 738        if (!uid_valid(kuid))
 739                return old_fsuid;
 740
 741        new = prepare_creds();
 742        if (!new)
 743                return old_fsuid;
 744
 745        if (uid_eq(kuid, old->uid)  || uid_eq(kuid, old->euid)  ||
 746            uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
 747            ns_capable(old->user_ns, CAP_SETUID)) {
 748                if (!uid_eq(kuid, old->fsuid)) {
 749                        new->fsuid = kuid;
 750                        if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
 751                                goto change_okay;
 752                }
 753        }
 754
 755        abort_creds(new);
 756        return old_fsuid;
 757
 758change_okay:
 759        commit_creds(new);
 760        return old_fsuid;
 761}
 762
 763/*
 764 * Samma på svenska..
 765 */
 766SYSCALL_DEFINE1(setfsgid, gid_t, gid)
 767{
 768        const struct cred *old;
 769        struct cred *new;
 770        gid_t old_fsgid;
 771        kgid_t kgid;
 772
 773        old = current_cred();
 774        old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
 775
 776        kgid = make_kgid(old->user_ns, gid);
 777        if (!gid_valid(kgid))
 778                return old_fsgid;
 779
 780        new = prepare_creds();
 781        if (!new)
 782                return old_fsgid;
 783
 784        if (gid_eq(kgid, old->gid)  || gid_eq(kgid, old->egid)  ||
 785            gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
 786            ns_capable(old->user_ns, CAP_SETGID)) {
 787                if (!gid_eq(kgid, old->fsgid)) {
 788                        new->fsgid = kgid;
 789                        goto change_okay;
 790                }
 791        }
 792
 793        abort_creds(new);
 794        return old_fsgid;
 795
 796change_okay:
 797        commit_creds(new);
 798        return old_fsgid;
 799}
 800
 801/**
 802 * sys_getpid - return the thread group id of the current process
 803 *
 804 * Note, despite the name, this returns the tgid not the pid.  The tgid and
 805 * the pid are identical unless CLONE_THREAD was specified on clone() in
 806 * which case the tgid is the same in all threads of the same group.
 807 *
 808 * This is SMP safe as current->tgid does not change.
 809 */
 810SYSCALL_DEFINE0(getpid)
 811{
 812        return task_tgid_vnr(current);
 813}
 814
 815/* Thread ID - the internal kernel "pid" */
 816SYSCALL_DEFINE0(gettid)
 817{
 818        return task_pid_vnr(current);
 819}
 820
 821/*
 822 * Accessing ->real_parent is not SMP-safe, it could
 823 * change from under us. However, we can use a stale
 824 * value of ->real_parent under rcu_read_lock(), see
 825 * release_task()->call_rcu(delayed_put_task_struct).
 826 */
 827SYSCALL_DEFINE0(getppid)
 828{
 829        int pid;
 830
 831        rcu_read_lock();
 832        pid = task_tgid_vnr(rcu_dereference(current->real_parent));
 833        rcu_read_unlock();
 834
 835        return pid;
 836}
 837
 838SYSCALL_DEFINE0(getuid)
 839{
 840        /* Only we change this so SMP safe */
 841        return from_kuid_munged(current_user_ns(), current_uid());
 842}
 843
 844SYSCALL_DEFINE0(geteuid)
 845{
 846        /* Only we change this so SMP safe */
 847        return from_kuid_munged(current_user_ns(), current_euid());
 848}
 849
 850SYSCALL_DEFINE0(getgid)
 851{
 852        /* Only we change this so SMP safe */
 853        return from_kgid_munged(current_user_ns(), current_gid());
 854}
 855
 856SYSCALL_DEFINE0(getegid)
 857{
 858        /* Only we change this so SMP safe */
 859        return from_kgid_munged(current_user_ns(), current_egid());
 860}
 861
 862void do_sys_times(struct tms *tms)
 863{
 864        cputime_t tgutime, tgstime, cutime, cstime;
 865
 866        spin_lock_irq(&current->sighand->siglock);
 867        thread_group_cputime_adjusted(current, &tgutime, &tgstime);
 868        cutime = current->signal->cutime;
 869        cstime = current->signal->cstime;
 870        spin_unlock_irq(&current->sighand->siglock);
 871        tms->tms_utime = cputime_to_clock_t(tgutime);
 872        tms->tms_stime = cputime_to_clock_t(tgstime);
 873        tms->tms_cutime = cputime_to_clock_t(cutime);
 874        tms->tms_cstime = cputime_to_clock_t(cstime);
 875}
 876
 877SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
 878{
 879        if (tbuf) {
 880                struct tms tmp;
 881
 882                do_sys_times(&tmp);
 883                if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
 884                        return -EFAULT;
 885        }
 886        force_successful_syscall_return();
 887        return (long) jiffies_64_to_clock_t(get_jiffies_64());
 888}
 889
 890/*
 891 * This needs some heavy checking ...
 892 * I just haven't the stomach for it. I also don't fully
 893 * understand sessions/pgrp etc. Let somebody who does explain it.
 894 *
 895 * OK, I think I have the protection semantics right.... this is really
 896 * only important on a multi-user system anyway, to make sure one user
 897 * can't send a signal to a process owned by another.  -TYT, 12/12/91
 898 *
 899 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 900 * LBT 04.03.94
 901 */
 902SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
 903{
 904        struct task_struct *p;
 905        struct task_struct *group_leader = current->group_leader;
 906        struct pid *pgrp;
 907        int err;
 908
 909        if (!pid)
 910                pid = task_pid_vnr(group_leader);
 911        if (!pgid)
 912                pgid = pid;
 913        if (pgid < 0)
 914                return -EINVAL;
 915        rcu_read_lock();
 916
 917        /* From this point forward we keep holding onto the tasklist lock
 918         * so that our parent does not change from under us. -DaveM
 919         */
 920        write_lock_irq(&tasklist_lock);
 921
 922        err = -ESRCH;
 923        p = find_task_by_vpid(pid);
 924        if (!p)
 925                goto out;
 926
 927        err = -EINVAL;
 928        if (!thread_group_leader(p))
 929                goto out;
 930
 931        if (same_thread_group(p->real_parent, group_leader)) {
 932                err = -EPERM;
 933                if (task_session(p) != task_session(group_leader))
 934                        goto out;
 935                err = -EACCES;
 936                if (p->did_exec)
 937                        goto out;
 938        } else {
 939                err = -ESRCH;
 940                if (p != group_leader)
 941                        goto out;
 942        }
 943
 944        err = -EPERM;
 945        if (p->signal->leader)
 946                goto out;
 947
 948        pgrp = task_pid(p);
 949        if (pgid != pid) {
 950                struct task_struct *g;
 951
 952                pgrp = find_vpid(pgid);
 953                g = pid_task(pgrp, PIDTYPE_PGID);
 954                if (!g || task_session(g) != task_session(group_leader))
 955                        goto out;
 956        }
 957
 958        err = security_task_setpgid(p, pgid);
 959        if (err)
 960                goto out;
 961
 962        if (task_pgrp(p) != pgrp)
 963                change_pid(p, PIDTYPE_PGID, pgrp);
 964
 965        err = 0;
 966out:
 967        /* All paths lead to here, thus we are safe. -DaveM */
 968        write_unlock_irq(&tasklist_lock);
 969        rcu_read_unlock();
 970        return err;
 971}
 972
 973SYSCALL_DEFINE1(getpgid, pid_t, pid)
 974{
 975        struct task_struct *p;
 976        struct pid *grp;
 977        int retval;
 978
 979        rcu_read_lock();
 980        if (!pid)
 981                grp = task_pgrp(current);
 982        else {
 983                retval = -ESRCH;
 984                p = find_task_by_vpid(pid);
 985                if (!p)
 986                        goto out;
 987                grp = task_pgrp(p);
 988                if (!grp)
 989                        goto out;
 990
 991                retval = security_task_getpgid(p);
 992                if (retval)
 993                        goto out;
 994        }
 995        retval = pid_vnr(grp);
 996out:
 997        rcu_read_unlock();
 998        return retval;
 999}
1000
1001#ifdef __ARCH_WANT_SYS_GETPGRP
1002
1003SYSCALL_DEFINE0(getpgrp)
1004{
1005        return sys_getpgid(0);
1006}
1007
1008#endif
1009
1010SYSCALL_DEFINE1(getsid, pid_t, pid)
1011{
1012        struct task_struct *p;
1013        struct pid *sid;
1014        int retval;
1015
1016        rcu_read_lock();
1017        if (!pid)
1018                sid = task_session(current);
1019        else {
1020                retval = -ESRCH;
1021                p = find_task_by_vpid(pid);
1022                if (!p)
1023                        goto out;
1024                sid = task_session(p);
1025                if (!sid)
1026                        goto out;
1027
1028                retval = security_task_getsid(p);
1029                if (retval)
1030                        goto out;
1031        }
1032        retval = pid_vnr(sid);
1033out:
1034        rcu_read_unlock();
1035        return retval;
1036}
1037
1038static void set_special_pids(struct pid *pid)
1039{
1040        struct task_struct *curr = current->group_leader;
1041
1042        if (task_session(curr) != pid)
1043                change_pid(curr, PIDTYPE_SID, pid);
1044
1045        if (task_pgrp(curr) != pid)
1046                change_pid(curr, PIDTYPE_PGID, pid);
1047}
1048
1049SYSCALL_DEFINE0(setsid)
1050{
1051        struct task_struct *group_leader = current->group_leader;
1052        struct pid *sid = task_pid(group_leader);
1053        pid_t session = pid_vnr(sid);
1054        int err = -EPERM;
1055
1056        write_lock_irq(&tasklist_lock);
1057        /* Fail if I am already a session leader */
1058        if (group_leader->signal->leader)
1059                goto out;
1060
1061        /* Fail if a process group id already exists that equals the
1062         * proposed session id.
1063         */
1064        if (pid_task(sid, PIDTYPE_PGID))
1065                goto out;
1066
1067        group_leader->signal->leader = 1;
1068        set_special_pids(sid);
1069
1070        proc_clear_tty(group_leader);
1071
1072        err = session;
1073out:
1074        write_unlock_irq(&tasklist_lock);
1075        if (err > 0) {
1076                proc_sid_connector(group_leader);
1077                sched_autogroup_create_attach(group_leader);
1078        }
1079        return err;
1080}
1081
1082DECLARE_RWSEM(uts_sem);
1083
1084#ifdef COMPAT_UTS_MACHINE
1085#define override_architecture(name) \
1086        (personality(current->personality) == PER_LINUX32 && \
1087         copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1088                      sizeof(COMPAT_UTS_MACHINE)))
1089#else
1090#define override_architecture(name)     0
1091#endif
1092
1093/*
1094 * Work around broken programs that cannot handle "Linux 3.0".
1095 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1096 */
1097static int override_release(char __user *release, size_t len)
1098{
1099        int ret = 0;
1100
1101        if (current->personality & UNAME26) {
1102                const char *rest = UTS_RELEASE;
1103                char buf[65] = { 0 };
1104                int ndots = 0;
1105                unsigned v;
1106                size_t copy;
1107
1108                while (*rest) {
1109                        if (*rest == '.' && ++ndots >= 3)
1110                                break;
1111                        if (!isdigit(*rest) && *rest != '.')
1112                                break;
1113                        rest++;
1114                }
1115                v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
1116                copy = clamp_t(size_t, len, 1, sizeof(buf));
1117                copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1118                ret = copy_to_user(release, buf, copy + 1);
1119        }
1120        return ret;
1121}
1122
1123SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1124{
1125        int errno = 0;
1126
1127        down_read(&uts_sem);
1128        if (copy_to_user(name, utsname(), sizeof *name))
1129                errno = -EFAULT;
1130        up_read(&uts_sem);
1131
1132        if (!errno && override_release(name->release, sizeof(name->release)))
1133                errno = -EFAULT;
1134        if (!errno && override_architecture(name))
1135                errno = -EFAULT;
1136        return errno;
1137}
1138
1139#ifdef __ARCH_WANT_SYS_OLD_UNAME
1140/*
1141 * Old cruft
1142 */
1143SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1144{
1145        int error = 0;
1146
1147        if (!name)
1148                return -EFAULT;
1149
1150        down_read(&uts_sem);
1151        if (copy_to_user(name, utsname(), sizeof(*name)))
1152                error = -EFAULT;
1153        up_read(&uts_sem);
1154
1155        if (!error && override_release(name->release, sizeof(name->release)))
1156                error = -EFAULT;
1157        if (!error && override_architecture(name))
1158                error = -EFAULT;
1159        return error;
1160}
1161
1162SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1163{
1164        int error;
1165
1166        if (!name)
1167                return -EFAULT;
1168        if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1169                return -EFAULT;
1170
1171        down_read(&uts_sem);
1172        error = __copy_to_user(&name->sysname, &utsname()->sysname,
1173                               __OLD_UTS_LEN);
1174        error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1175        error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1176                                __OLD_UTS_LEN);
1177        error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1178        error |= __copy_to_user(&name->release, &utsname()->release,
1179                                __OLD_UTS_LEN);
1180        error |= __put_user(0, name->release + __OLD_UTS_LEN);
1181        error |= __copy_to_user(&name->version, &utsname()->version,
1182                                __OLD_UTS_LEN);
1183        error |= __put_user(0, name->version + __OLD_UTS_LEN);
1184        error |= __copy_to_user(&name->machine, &utsname()->machine,
1185                                __OLD_UTS_LEN);
1186        error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1187        up_read(&uts_sem);
1188
1189        if (!error && override_architecture(name))
1190                error = -EFAULT;
1191        if (!error && override_release(name->release, sizeof(name->release)))
1192                error = -EFAULT;
1193        return error ? -EFAULT : 0;
1194}
1195#endif
1196
1197SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1198{
1199        int errno;
1200        char tmp[__NEW_UTS_LEN];
1201
1202        if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1203                return -EPERM;
1204
1205        if (len < 0 || len > __NEW_UTS_LEN)
1206                return -EINVAL;
1207        down_write(&uts_sem);
1208        errno = -EFAULT;
1209        if (!copy_from_user(tmp, name, len)) {
1210                struct new_utsname *u = utsname();
1211
1212                memcpy(u->nodename, tmp, len);
1213                memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1214                errno = 0;
1215                uts_proc_notify(UTS_PROC_HOSTNAME);
1216        }
1217        up_write(&uts_sem);
1218        return errno;
1219}
1220
1221#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1222
1223SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1224{
1225        int i, errno;
1226        struct new_utsname *u;
1227
1228        if (len < 0)
1229                return -EINVAL;
1230        down_read(&uts_sem);
1231        u = utsname();
1232        i = 1 + strlen(u->nodename);
1233        if (i > len)
1234                i = len;
1235        errno = 0;
1236        if (copy_to_user(name, u->nodename, i))
1237                errno = -EFAULT;
1238        up_read(&uts_sem);
1239        return errno;
1240}
1241
1242#endif
1243
1244/*
1245 * Only setdomainname; getdomainname can be implemented by calling
1246 * uname()
1247 */
1248SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1249{
1250        int errno;
1251        char tmp[__NEW_UTS_LEN];
1252
1253        if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1254                return -EPERM;
1255        if (len < 0 || len > __NEW_UTS_LEN)
1256                return -EINVAL;
1257
1258        down_write(&uts_sem);
1259        errno = -EFAULT;
1260        if (!copy_from_user(tmp, name, len)) {
1261                struct new_utsname *u = utsname();
1262
1263                memcpy(u->domainname, tmp, len);
1264                memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1265                errno = 0;
1266                uts_proc_notify(UTS_PROC_DOMAINNAME);
1267        }
1268        up_write(&uts_sem);
1269        return errno;
1270}
1271
1272SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1273{
1274        struct rlimit value;
1275        int ret;
1276
1277        ret = do_prlimit(current, resource, NULL, &value);
1278        if (!ret)
1279                ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1280
1281        return ret;
1282}
1283
1284#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1285
1286/*
1287 *      Back compatibility for getrlimit. Needed for some apps.
1288 */
1289 
1290SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1291                struct rlimit __user *, rlim)
1292{
1293        struct rlimit x;
1294        if (resource >= RLIM_NLIMITS)
1295                return -EINVAL;
1296
1297        task_lock(current->group_leader);
1298        x = current->signal->rlim[resource];
1299        task_unlock(current->group_leader);
1300        if (x.rlim_cur > 0x7FFFFFFF)
1301                x.rlim_cur = 0x7FFFFFFF;
1302        if (x.rlim_max > 0x7FFFFFFF)
1303                x.rlim_max = 0x7FFFFFFF;
1304        return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1305}
1306
1307#endif
1308
1309static inline bool rlim64_is_infinity(__u64 rlim64)
1310{
1311#if BITS_PER_LONG < 64
1312        return rlim64 >= ULONG_MAX;
1313#else
1314        return rlim64 == RLIM64_INFINITY;
1315#endif
1316}
1317
1318static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1319{
1320        if (rlim->rlim_cur == RLIM_INFINITY)
1321                rlim64->rlim_cur = RLIM64_INFINITY;
1322        else
1323                rlim64->rlim_cur = rlim->rlim_cur;
1324        if (rlim->rlim_max == RLIM_INFINITY)
1325                rlim64->rlim_max = RLIM64_INFINITY;
1326        else
1327                rlim64->rlim_max = rlim->rlim_max;
1328}
1329
1330static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1331{
1332        if (rlim64_is_infinity(rlim64->rlim_cur))
1333                rlim->rlim_cur = RLIM_INFINITY;
1334        else
1335                rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1336        if (rlim64_is_infinity(rlim64->rlim_max))
1337                rlim->rlim_max = RLIM_INFINITY;
1338        else
1339                rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1340}
1341
1342/* make sure you are allowed to change @tsk limits before calling this */
1343int do_prlimit(struct task_struct *tsk, unsigned int resource,
1344                struct rlimit *new_rlim, struct rlimit *old_rlim)
1345{
1346        struct rlimit *rlim;
1347        int retval = 0;
1348
1349        if (resource >= RLIM_NLIMITS)
1350                return -EINVAL;
1351        if (new_rlim) {
1352                if (new_rlim->rlim_cur > new_rlim->rlim_max)
1353                        return -EINVAL;
1354                if (resource == RLIMIT_NOFILE &&
1355                                new_rlim->rlim_max > sysctl_nr_open)
1356                        return -EPERM;
1357        }
1358
1359        /* protect tsk->signal and tsk->sighand from disappearing */
1360        read_lock(&tasklist_lock);
1361        if (!tsk->sighand) {
1362                retval = -ESRCH;
1363                goto out;
1364        }
1365
1366        rlim = tsk->signal->rlim + resource;
1367        task_lock(tsk->group_leader);
1368        if (new_rlim) {
1369                /* Keep the capable check against init_user_ns until
1370                   cgroups can contain all limits */
1371                if (new_rlim->rlim_max > rlim->rlim_max &&
1372                                !capable(CAP_SYS_RESOURCE))
1373                        retval = -EPERM;
1374                if (!retval)
1375                        retval = security_task_setrlimit(tsk->group_leader,
1376                                        resource, new_rlim);
1377                if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1378                        /*
1379                         * The caller is asking for an immediate RLIMIT_CPU
1380                         * expiry.  But we use the zero value to mean "it was
1381                         * never set".  So let's cheat and make it one second
1382                         * instead
1383                         */
1384                        new_rlim->rlim_cur = 1;
1385                }
1386        }
1387        if (!retval) {
1388                if (old_rlim)
1389                        *old_rlim = *rlim;
1390                if (new_rlim)
1391                        *rlim = *new_rlim;
1392        }
1393        task_unlock(tsk->group_leader);
1394
1395        /*
1396         * RLIMIT_CPU handling.   Note that the kernel fails to return an error
1397         * code if it rejected the user's attempt to set RLIMIT_CPU.  This is a
1398         * very long-standing error, and fixing it now risks breakage of
1399         * applications, so we live with it
1400         */
1401         if (!retval && new_rlim && resource == RLIMIT_CPU &&
1402                         new_rlim->rlim_cur != RLIM_INFINITY)
1403                update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1404out:
1405        read_unlock(&tasklist_lock);
1406        return retval;
1407}
1408
1409/* rcu lock must be held */
1410static int check_prlimit_permission(struct task_struct *task)
1411{
1412        const struct cred *cred = current_cred(), *tcred;
1413
1414        if (current == task)
1415                return 0;
1416
1417        tcred = __task_cred(task);
1418        if (uid_eq(cred->uid, tcred->euid) &&
1419            uid_eq(cred->uid, tcred->suid) &&
1420            uid_eq(cred->uid, tcred->uid)  &&
1421            gid_eq(cred->gid, tcred->egid) &&
1422            gid_eq(cred->gid, tcred->sgid) &&
1423            gid_eq(cred->gid, tcred->gid))
1424                return 0;
1425        if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1426                return 0;
1427
1428        return -EPERM;
1429}
1430
1431SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1432                const struct rlimit64 __user *, new_rlim,
1433                struct rlimit64 __user *, old_rlim)
1434{
1435        struct rlimit64 old64, new64;
1436        struct rlimit old, new;
1437        struct task_struct *tsk;
1438        int ret;
1439
1440        if (new_rlim) {
1441                if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1442                        return -EFAULT;
1443                rlim64_to_rlim(&new64, &new);
1444        }
1445
1446        rcu_read_lock();
1447        tsk = pid ? find_task_by_vpid(pid) : current;
1448        if (!tsk) {
1449                rcu_read_unlock();
1450                return -ESRCH;
1451        }
1452        ret = check_prlimit_permission(tsk);
1453        if (ret) {
1454                rcu_read_unlock();
1455                return ret;
1456        }
1457        get_task_struct(tsk);
1458        rcu_read_unlock();
1459
1460        ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1461                        old_rlim ? &old : NULL);
1462
1463        if (!ret && old_rlim) {
1464                rlim_to_rlim64(&old, &old64);
1465                if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1466                        ret = -EFAULT;
1467        }
1468
1469        put_task_struct(tsk);
1470        return ret;
1471}
1472
1473SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1474{
1475        struct rlimit new_rlim;
1476
1477        if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1478                return -EFAULT;
1479        return do_prlimit(current, resource, &new_rlim, NULL);
1480}
1481
1482/*
1483 * It would make sense to put struct rusage in the task_struct,
1484 * except that would make the task_struct be *really big*.  After
1485 * task_struct gets moved into malloc'ed memory, it would
1486 * make sense to do this.  It will make moving the rest of the information
1487 * a lot simpler!  (Which we're not doing right now because we're not
1488 * measuring them yet).
1489 *
1490 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1491 * races with threads incrementing their own counters.  But since word
1492 * reads are atomic, we either get new values or old values and we don't
1493 * care which for the sums.  We always take the siglock to protect reading
1494 * the c* fields from p->signal from races with exit.c updating those
1495 * fields when reaping, so a sample either gets all the additions of a
1496 * given child after it's reaped, or none so this sample is before reaping.
1497 *
1498 * Locking:
1499 * We need to take the siglock for CHILDEREN, SELF and BOTH
1500 * for  the cases current multithreaded, non-current single threaded
1501 * non-current multithreaded.  Thread traversal is now safe with
1502 * the siglock held.
1503 * Strictly speaking, we donot need to take the siglock if we are current and
1504 * single threaded,  as no one else can take our signal_struct away, no one
1505 * else can  reap the  children to update signal->c* counters, and no one else
1506 * can race with the signal-> fields. If we do not take any lock, the
1507 * signal-> fields could be read out of order while another thread was just
1508 * exiting. So we should  place a read memory barrier when we avoid the lock.
1509 * On the writer side,  write memory barrier is implied in  __exit_signal
1510 * as __exit_signal releases  the siglock spinlock after updating the signal->
1511 * fields. But we don't do this yet to keep things simple.
1512 *
1513 */
1514
1515static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1516{
1517        r->ru_nvcsw += t->nvcsw;
1518        r->ru_nivcsw += t->nivcsw;
1519        r->ru_minflt += t->min_flt;
1520        r->ru_majflt += t->maj_flt;
1521        r->ru_inblock += task_io_get_inblock(t);
1522        r->ru_oublock += task_io_get_oublock(t);
1523}
1524
1525static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1526{
1527        struct task_struct *t;
1528        unsigned long flags;
1529        cputime_t tgutime, tgstime, utime, stime;
1530        unsigned long maxrss = 0;
1531
1532        memset((char *) r, 0, sizeof *r);
1533        utime = stime = 0;
1534
1535        if (who == RUSAGE_THREAD) {
1536                task_cputime_adjusted(current, &utime, &stime);
1537                accumulate_thread_rusage(p, r);
1538                maxrss = p->signal->maxrss;
1539                goto out;
1540        }
1541
1542        if (!lock_task_sighand(p, &flags))
1543                return;
1544
1545        switch (who) {
1546                case RUSAGE_BOTH:
1547                case RUSAGE_CHILDREN:
1548                        utime = p->signal->cutime;
1549                        stime = p->signal->cstime;
1550                        r->ru_nvcsw = p->signal->cnvcsw;
1551                        r->ru_nivcsw = p->signal->cnivcsw;
1552                        r->ru_minflt = p->signal->cmin_flt;
1553                        r->ru_majflt = p->signal->cmaj_flt;
1554                        r->ru_inblock = p->signal->cinblock;
1555                        r->ru_oublock = p->signal->coublock;
1556                        maxrss = p->signal->cmaxrss;
1557
1558                        if (who == RUSAGE_CHILDREN)
1559                                break;
1560
1561                case RUSAGE_SELF:
1562                        thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1563                        utime += tgutime;
1564                        stime += tgstime;
1565                        r->ru_nvcsw += p->signal->nvcsw;
1566                        r->ru_nivcsw += p->signal->nivcsw;
1567                        r->ru_minflt += p->signal->min_flt;
1568                        r->ru_majflt += p->signal->maj_flt;
1569                        r->ru_inblock += p->signal->inblock;
1570                        r->ru_oublock += p->signal->oublock;
1571                        if (maxrss < p->signal->maxrss)
1572                                maxrss = p->signal->maxrss;
1573                        t = p;
1574                        do {
1575                                accumulate_thread_rusage(t, r);
1576                                t = next_thread(t);
1577                        } while (t != p);
1578                        break;
1579
1580                default:
1581                        BUG();
1582        }
1583        unlock_task_sighand(p, &flags);
1584
1585out:
1586        cputime_to_timeval(utime, &r->ru_utime);
1587        cputime_to_timeval(stime, &r->ru_stime);
1588
1589        if (who != RUSAGE_CHILDREN) {
1590                struct mm_struct *mm = get_task_mm(p);
1591                if (mm) {
1592                        setmax_mm_hiwater_rss(&maxrss, mm);
1593                        mmput(mm);
1594                }
1595        }
1596        r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1597}
1598
1599int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1600{
1601        struct rusage r;
1602        k_getrusage(p, who, &r);
1603        return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1604}
1605
1606SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1607{
1608        if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1609            who != RUSAGE_THREAD)
1610                return -EINVAL;
1611        return getrusage(current, who, ru);
1612}
1613
1614#ifdef CONFIG_COMPAT
1615COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1616{
1617        struct rusage r;
1618
1619        if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1620            who != RUSAGE_THREAD)
1621                return -EINVAL;
1622
1623        k_getrusage(current, who, &r);
1624        return put_compat_rusage(&r, ru);
1625}
1626#endif
1627
1628SYSCALL_DEFINE1(umask, int, mask)
1629{
1630        mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1631        return mask;
1632}
1633
1634static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1635{
1636        struct fd exe;
1637        struct inode *inode;
1638        int err;
1639
1640        exe = fdget(fd);
1641        if (!exe.file)
1642                return -EBADF;
1643
1644        inode = file_inode(exe.file);
1645
1646        /*
1647         * Because the original mm->exe_file points to executable file, make
1648         * sure that this one is executable as well, to avoid breaking an
1649         * overall picture.
1650         */
1651        err = -EACCES;
1652        if (!S_ISREG(inode->i_mode)     ||
1653            exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1654                goto exit;
1655
1656        err = inode_permission(inode, MAY_EXEC);
1657        if (err)
1658                goto exit;
1659
1660        down_write(&mm->mmap_sem);
1661
1662        /*
1663         * Forbid mm->exe_file change if old file still mapped.
1664         */
1665        err = -EBUSY;
1666        if (mm->exe_file) {
1667                struct vm_area_struct *vma;
1668
1669                for (vma = mm->mmap; vma; vma = vma->vm_next)
1670                        if (vma->vm_file &&
1671                            path_equal(&vma->vm_file->f_path,
1672                                       &mm->exe_file->f_path))
1673                                goto exit_unlock;
1674        }
1675
1676        /*
1677         * The symlink can be changed only once, just to disallow arbitrary
1678         * transitions malicious software might bring in. This means one
1679         * could make a snapshot over all processes running and monitor
1680         * /proc/pid/exe changes to notice unusual activity if needed.
1681         */
1682        err = -EPERM;
1683        if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1684                goto exit_unlock;
1685
1686        err = 0;
1687        set_mm_exe_file(mm, exe.file);  /* this grabs a reference to exe.file */
1688exit_unlock:
1689        up_write(&mm->mmap_sem);
1690
1691exit:
1692        fdput(exe);
1693        return err;
1694}
1695
1696static int prctl_set_mm(int opt, unsigned long addr,
1697                        unsigned long arg4, unsigned long arg5)
1698{
1699        unsigned long rlim = rlimit(RLIMIT_DATA);
1700        struct mm_struct *mm = current->mm;
1701        struct vm_area_struct *vma;
1702        int error;
1703
1704        if (arg5 || (arg4 && opt != PR_SET_MM_AUXV))
1705                return -EINVAL;
1706
1707        if (!capable(CAP_SYS_RESOURCE))
1708                return -EPERM;
1709
1710        if (opt == PR_SET_MM_EXE_FILE)
1711                return prctl_set_mm_exe_file(mm, (unsigned int)addr);
1712
1713        if (addr >= TASK_SIZE || addr < mmap_min_addr)
1714                return -EINVAL;
1715
1716        error = -EINVAL;
1717
1718        down_read(&mm->mmap_sem);
1719        vma = find_vma(mm, addr);
1720
1721        switch (opt) {
1722        case PR_SET_MM_START_CODE:
1723                mm->start_code = addr;
1724                break;
1725        case PR_SET_MM_END_CODE:
1726                mm->end_code = addr;
1727                break;
1728        case PR_SET_MM_START_DATA:
1729                mm->start_data = addr;
1730                break;
1731        case PR_SET_MM_END_DATA:
1732                mm->end_data = addr;
1733                break;
1734
1735        case PR_SET_MM_START_BRK:
1736                if (addr <= mm->end_data)
1737                        goto out;
1738
1739                if (rlim < RLIM_INFINITY &&
1740                    (mm->brk - addr) +
1741                    (mm->end_data - mm->start_data) > rlim)
1742                        goto out;
1743
1744                mm->start_brk = addr;
1745                break;
1746
1747        case PR_SET_MM_BRK:
1748                if (addr <= mm->end_data)
1749                        goto out;
1750
1751                if (rlim < RLIM_INFINITY &&
1752                    (addr - mm->start_brk) +
1753                    (mm->end_data - mm->start_data) > rlim)
1754                        goto out;
1755
1756                mm->brk = addr;
1757                break;
1758
1759        /*
1760         * If command line arguments and environment
1761         * are placed somewhere else on stack, we can
1762         * set them up here, ARG_START/END to setup
1763         * command line argumets and ENV_START/END
1764         * for environment.
1765         */
1766        case PR_SET_MM_START_STACK:
1767        case PR_SET_MM_ARG_START:
1768        case PR_SET_MM_ARG_END:
1769        case PR_SET_MM_ENV_START:
1770        case PR_SET_MM_ENV_END:
1771                if (!vma) {
1772                        error = -EFAULT;
1773                        goto out;
1774                }
1775                if (opt == PR_SET_MM_START_STACK)
1776                        mm->start_stack = addr;
1777                else if (opt == PR_SET_MM_ARG_START)
1778                        mm->arg_start = addr;
1779                else if (opt == PR_SET_MM_ARG_END)
1780                        mm->arg_end = addr;
1781                else if (opt == PR_SET_MM_ENV_START)
1782                        mm->env_start = addr;
1783                else if (opt == PR_SET_MM_ENV_END)
1784                        mm->env_end = addr;
1785                break;
1786
1787        /*
1788         * This doesn't move auxiliary vector itself
1789         * since it's pinned to mm_struct, but allow
1790         * to fill vector with new values. It's up
1791         * to a caller to provide sane values here
1792         * otherwise user space tools which use this
1793         * vector might be unhappy.
1794         */
1795        case PR_SET_MM_AUXV: {
1796                unsigned long user_auxv[AT_VECTOR_SIZE];
1797
1798                if (arg4 > sizeof(user_auxv))
1799                        goto out;
1800                up_read(&mm->mmap_sem);
1801
1802                if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
1803                        return -EFAULT;
1804
1805                /* Make sure the last entry is always AT_NULL */
1806                user_auxv[AT_VECTOR_SIZE - 2] = 0;
1807                user_auxv[AT_VECTOR_SIZE - 1] = 0;
1808
1809                BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1810
1811                task_lock(current);
1812                memcpy(mm->saved_auxv, user_auxv, arg4);
1813                task_unlock(current);
1814
1815                return 0;
1816        }
1817        default:
1818                goto out;
1819        }
1820
1821        error = 0;
1822out:
1823        up_read(&mm->mmap_sem);
1824        return error;
1825}
1826
1827#ifdef CONFIG_CHECKPOINT_RESTORE
1828static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
1829{
1830        return put_user(me->clear_child_tid, tid_addr);
1831}
1832#else
1833static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
1834{
1835        return -EINVAL;
1836}
1837#endif
1838
1839SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
1840                unsigned long, arg4, unsigned long, arg5)
1841{
1842        struct task_struct *me = current;
1843        unsigned char comm[sizeof(me->comm)];
1844        long error;
1845
1846        error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1847        if (error != -ENOSYS)
1848                return error;
1849
1850        error = 0;
1851        switch (option) {
1852        case PR_SET_PDEATHSIG:
1853                if (!valid_signal(arg2)) {
1854                        error = -EINVAL;
1855                        break;
1856                }
1857                me->pdeath_signal = arg2;
1858                break;
1859        case PR_GET_PDEATHSIG:
1860                error = put_user(me->pdeath_signal, (int __user *)arg2);
1861                break;
1862        case PR_GET_DUMPABLE:
1863                error = get_dumpable(me->mm);
1864                break;
1865        case PR_SET_DUMPABLE:
1866                if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
1867                        error = -EINVAL;
1868                        break;
1869                }
1870                set_dumpable(me->mm, arg2);
1871                break;
1872
1873        case PR_SET_UNALIGN:
1874                error = SET_UNALIGN_CTL(me, arg2);
1875                break;
1876        case PR_GET_UNALIGN:
1877                error = GET_UNALIGN_CTL(me, arg2);
1878                break;
1879        case PR_SET_FPEMU:
1880                error = SET_FPEMU_CTL(me, arg2);
1881                break;
1882        case PR_GET_FPEMU:
1883                error = GET_FPEMU_CTL(me, arg2);
1884                break;
1885        case PR_SET_FPEXC:
1886                error = SET_FPEXC_CTL(me, arg2);
1887                break;
1888        case PR_GET_FPEXC:
1889                error = GET_FPEXC_CTL(me, arg2);
1890                break;
1891        case PR_GET_TIMING:
1892                error = PR_TIMING_STATISTICAL;
1893                break;
1894        case PR_SET_TIMING:
1895                if (arg2 != PR_TIMING_STATISTICAL)
1896                        error = -EINVAL;
1897                break;
1898        case PR_SET_NAME:
1899                comm[sizeof(me->comm) - 1] = 0;
1900                if (strncpy_from_user(comm, (char __user *)arg2,
1901                                      sizeof(me->comm) - 1) < 0)
1902                        return -EFAULT;
1903                set_task_comm(me, comm);
1904                proc_comm_connector(me);
1905                break;
1906        case PR_GET_NAME:
1907                get_task_comm(comm, me);
1908                if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
1909                        return -EFAULT;
1910                break;
1911        case PR_GET_ENDIAN:
1912                error = GET_ENDIAN(me, arg2);
1913                break;
1914        case PR_SET_ENDIAN:
1915                error = SET_ENDIAN(me, arg2);
1916                break;
1917        case PR_GET_SECCOMP:
1918                error = prctl_get_seccomp();
1919                break;
1920        case PR_SET_SECCOMP:
1921                error = prctl_set_seccomp(arg2, (char __user *)arg3);
1922                break;
1923        case PR_GET_TSC:
1924                error = GET_TSC_CTL(arg2);
1925                break;
1926        case PR_SET_TSC:
1927                error = SET_TSC_CTL(arg2);
1928                break;
1929        case PR_TASK_PERF_EVENTS_DISABLE:
1930                error = perf_event_task_disable();
1931                break;
1932        case PR_TASK_PERF_EVENTS_ENABLE:
1933                error = perf_event_task_enable();
1934                break;
1935        case PR_GET_TIMERSLACK:
1936                error = current->timer_slack_ns;
1937                break;
1938        case PR_SET_TIMERSLACK:
1939                if (arg2 <= 0)
1940                        current->timer_slack_ns =
1941                                        current->default_timer_slack_ns;
1942                else
1943                        current->timer_slack_ns = arg2;
1944                break;
1945        case PR_MCE_KILL:
1946                if (arg4 | arg5)
1947                        return -EINVAL;
1948                switch (arg2) {
1949                case PR_MCE_KILL_CLEAR:
1950                        if (arg3 != 0)
1951                                return -EINVAL;
1952                        current->flags &= ~PF_MCE_PROCESS;
1953                        break;
1954                case PR_MCE_KILL_SET:
1955                        current->flags |= PF_MCE_PROCESS;
1956                        if (arg3 == PR_MCE_KILL_EARLY)
1957                                current->flags |= PF_MCE_EARLY;
1958                        else if (arg3 == PR_MCE_KILL_LATE)
1959                                current->flags &= ~PF_MCE_EARLY;
1960                        else if (arg3 == PR_MCE_KILL_DEFAULT)
1961                                current->flags &=
1962                                                ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1963                        else
1964                                return -EINVAL;
1965                        break;
1966                default:
1967                        return -EINVAL;
1968                }
1969                break;
1970        case PR_MCE_KILL_GET:
1971                if (arg2 | arg3 | arg4 | arg5)
1972                        return -EINVAL;
1973                if (current->flags & PF_MCE_PROCESS)
1974                        error = (current->flags & PF_MCE_EARLY) ?
1975                                PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
1976                else
1977                        error = PR_MCE_KILL_DEFAULT;
1978                break;
1979        case PR_SET_MM:
1980                error = prctl_set_mm(arg2, arg3, arg4, arg5);
1981                break;
1982        case PR_GET_TID_ADDRESS:
1983                error = prctl_get_tid_address(me, (int __user **)arg2);
1984                break;
1985        case PR_SET_CHILD_SUBREAPER:
1986                me->signal->is_child_subreaper = !!arg2;
1987                break;
1988        case PR_GET_CHILD_SUBREAPER:
1989                error = put_user(me->signal->is_child_subreaper,
1990                                 (int __user *)arg2);
1991                break;
1992        case PR_SET_NO_NEW_PRIVS:
1993                if (arg2 != 1 || arg3 || arg4 || arg5)
1994                        return -EINVAL;
1995
1996                current->no_new_privs = 1;
1997                break;
1998        case PR_GET_NO_NEW_PRIVS:
1999                if (arg2 || arg3 || arg4 || arg5)
2000                        return -EINVAL;
2001                return current->no_new_privs ? 1 : 0;
2002        default:
2003                error = -EINVAL;
2004                break;
2005        }
2006        return error;
2007}
2008
2009SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2010                struct getcpu_cache __user *, unused)
2011{
2012        int err = 0;
2013        int cpu = raw_smp_processor_id();
2014        if (cpup)
2015                err |= put_user(cpu, cpup);
2016        if (nodep)
2017                err |= put_user(cpu_to_node(cpu), nodep);
2018        return err ? -EFAULT : 0;
2019}
2020
2021/**
2022 * do_sysinfo - fill in sysinfo struct
2023 * @info: pointer to buffer to fill
2024 */
2025static int do_sysinfo(struct sysinfo *info)
2026{
2027        unsigned long mem_total, sav_total;
2028        unsigned int mem_unit, bitcount;
2029        struct timespec tp;
2030
2031        memset(info, 0, sizeof(struct sysinfo));
2032
2033        get_monotonic_boottime(&tp);
2034        info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2035
2036        get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2037
2038        info->procs = nr_threads;
2039
2040        si_meminfo(info);
2041        si_swapinfo(info);
2042
2043        /*
2044         * If the sum of all the available memory (i.e. ram + swap)
2045         * is less than can be stored in a 32 bit unsigned long then
2046         * we can be binary compatible with 2.2.x kernels.  If not,
2047         * well, in that case 2.2.x was broken anyways...
2048         *
2049         *  -Erik Andersen <andersee@debian.org>
2050         */
2051
2052        mem_total = info->totalram + info->totalswap;
2053        if (mem_total < info->totalram || mem_total < info->totalswap)
2054                goto out;
2055        bitcount = 0;
2056        mem_unit = info->mem_unit;
2057        while (mem_unit > 1) {
2058                bitcount++;
2059                mem_unit >>= 1;
2060                sav_total = mem_total;
2061                mem_total <<= 1;
2062                if (mem_total < sav_total)
2063                        goto out;
2064        }
2065
2066        /*
2067         * If mem_total did not overflow, multiply all memory values by
2068         * info->mem_unit and set it to 1.  This leaves things compatible
2069         * with 2.2.x, and also retains compatibility with earlier 2.4.x
2070         * kernels...
2071         */
2072
2073        info->mem_unit = 1;
2074        info->totalram <<= bitcount;
2075        info->freeram <<= bitcount;
2076        info->sharedram <<= bitcount;
2077        info->bufferram <<= bitcount;
2078        info->totalswap <<= bitcount;
2079        info->freeswap <<= bitcount;
2080        info->totalhigh <<= bitcount;
2081        info->freehigh <<= bitcount;
2082
2083out:
2084        return 0;
2085}
2086
2087SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2088{
2089        struct sysinfo val;
2090
2091        do_sysinfo(&val);
2092
2093        if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2094                return -EFAULT;
2095
2096        return 0;
2097}
2098
2099#ifdef CONFIG_COMPAT
2100struct compat_sysinfo {
2101        s32 uptime;
2102        u32 loads[3];
2103        u32 totalram;
2104        u32 freeram;
2105        u32 sharedram;
2106        u32 bufferram;
2107        u32 totalswap;
2108        u32 freeswap;
2109        u16 procs;
2110        u16 pad;
2111        u32 totalhigh;
2112        u32 freehigh;
2113        u32 mem_unit;
2114        char _f[20-2*sizeof(u32)-sizeof(int)];
2115};
2116
2117COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2118{
2119        struct sysinfo s;
2120
2121        do_sysinfo(&s);
2122
2123        /* Check to see if any memory value is too large for 32-bit and scale
2124         *  down if needed
2125         */
2126        if ((s.totalram >> 32) || (s.totalswap >> 32)) {
2127                int bitcount = 0;
2128
2129                while (s.mem_unit < PAGE_SIZE) {
2130                        s.mem_unit <<= 1;
2131                        bitcount++;
2132                }
2133
2134                s.totalram >>= bitcount;
2135                s.freeram >>= bitcount;
2136                s.sharedram >>= bitcount;
2137                s.bufferram >>= bitcount;
2138                s.totalswap >>= bitcount;
2139                s.freeswap >>= bitcount;
2140                s.totalhigh >>= bitcount;
2141                s.freehigh >>= bitcount;
2142        }
2143
2144        if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2145            __put_user(s.uptime, &info->uptime) ||
2146            __put_user(s.loads[0], &info->loads[0]) ||
2147            __put_user(s.loads[1], &info->loads[1]) ||
2148            __put_user(s.loads[2], &info->loads[2]) ||
2149            __put_user(s.totalram, &info->totalram) ||
2150            __put_user(s.freeram, &info->freeram) ||
2151            __put_user(s.sharedram, &info->sharedram) ||
2152            __put_user(s.bufferram, &info->bufferram) ||
2153            __put_user(s.totalswap, &info->totalswap) ||
2154            __put_user(s.freeswap, &info->freeswap) ||
2155            __put_user(s.procs, &info->procs) ||
2156            __put_user(s.totalhigh, &info->totalhigh) ||
2157            __put_user(s.freehigh, &info->freehigh) ||
2158            __put_user(s.mem_unit, &info->mem_unit))
2159                return -EFAULT;
2160
2161        return 0;
2162}
2163#endif /* CONFIG_COMPAT */
2164
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