linux/kernel/sysctl.c
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   1/*
   2 * sysctl.c: General linux system control interface
   3 *
   4 * Begun 24 March 1995, Stephen Tweedie
   5 * Added /proc support, Dec 1995
   6 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9 * Dynamic registration fixes, Stephen Tweedie.
  10 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12 *  Horn.
  13 * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14 * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15 * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16 *  Wendling.
  17 * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18 *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/mm.h>
  23#include <linux/swap.h>
  24#include <linux/slab.h>
  25#include <linux/sysctl.h>
  26#include <linux/proc_fs.h>
  27#include <linux/security.h>
  28#include <linux/ctype.h>
  29#include <linux/utsname.h>
  30#include <linux/smp_lock.h>
  31#include <linux/fs.h>
  32#include <linux/init.h>
  33#include <linux/kernel.h>
  34#include <linux/kobject.h>
  35#include <linux/net.h>
  36#include <linux/sysrq.h>
  37#include <linux/highuid.h>
  38#include <linux/writeback.h>
  39#include <linux/hugetlb.h>
  40#include <linux/security.h>
  41#include <linux/initrd.h>
  42#include <linux/times.h>
  43#include <linux/limits.h>
  44#include <linux/dcache.h>
  45#include <linux/syscalls.h>
  46#include <linux/nfs_fs.h>
  47#include <linux/acpi.h>
  48#include <linux/reboot.h>
  49
  50#include <asm/uaccess.h>
  51#include <asm/processor.h>
  52
  53#ifdef CONFIG_X86
  54#include <asm/nmi.h>
  55#include <asm/stacktrace.h>
  56#endif
  57
  58static int deprecated_sysctl_warning(struct __sysctl_args *args);
  59
  60#if defined(CONFIG_SYSCTL)
  61
  62/* External variables not in a header file. */
  63extern int C_A_D;
  64extern int print_fatal_signals;
  65extern int sysctl_overcommit_memory;
  66extern int sysctl_overcommit_ratio;
  67extern int sysctl_panic_on_oom;
  68extern int sysctl_oom_kill_allocating_task;
  69extern int max_threads;
  70extern int core_uses_pid;
  71extern int suid_dumpable;
  72extern char core_pattern[];
  73extern int pid_max;
  74extern int min_free_kbytes;
  75extern int printk_ratelimit_jiffies;
  76extern int printk_ratelimit_burst;
  77extern int pid_max_min, pid_max_max;
  78extern int sysctl_drop_caches;
  79extern int percpu_pagelist_fraction;
  80extern int compat_log;
  81extern int maps_protect;
  82extern int sysctl_stat_interval;
  83extern int audit_argv_kb;
  84
  85/* Constants used for minimum and  maximum */
  86#ifdef CONFIG_DETECT_SOFTLOCKUP
  87static int one = 1;
  88static int sixty = 60;
  89#endif
  90
  91#ifdef CONFIG_MMU
  92static int two = 2;
  93#endif
  94
  95static int zero;
  96static int one_hundred = 100;
  97
  98/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  99static int maxolduid = 65535;
 100static int minolduid;
 101static int min_percpu_pagelist_fract = 8;
 102
 103static int ngroups_max = NGROUPS_MAX;
 104
 105#ifdef CONFIG_KMOD
 106extern char modprobe_path[];
 107#endif
 108#ifdef CONFIG_CHR_DEV_SG
 109extern int sg_big_buff;
 110#endif
 111
 112#ifdef __sparc__
 113extern char reboot_command [];
 114extern int stop_a_enabled;
 115extern int scons_pwroff;
 116#endif
 117
 118#ifdef __hppa__
 119extern int pwrsw_enabled;
 120extern int unaligned_enabled;
 121#endif
 122
 123#ifdef CONFIG_S390
 124#ifdef CONFIG_MATHEMU
 125extern int sysctl_ieee_emulation_warnings;
 126#endif
 127extern int sysctl_userprocess_debug;
 128extern int spin_retry;
 129#endif
 130
 131extern int sysctl_hz_timer;
 132
 133#ifdef CONFIG_BSD_PROCESS_ACCT
 134extern int acct_parm[];
 135#endif
 136
 137#ifdef CONFIG_IA64
 138extern int no_unaligned_warning;
 139#endif
 140
 141#ifdef CONFIG_RT_MUTEXES
 142extern int max_lock_depth;
 143#endif
 144
 145#ifdef CONFIG_SYSCTL_SYSCALL
 146static int parse_table(int __user *, int, void __user *, size_t __user *,
 147                void __user *, size_t, struct ctl_table *);
 148#endif
 149
 150
 151#ifdef CONFIG_PROC_SYSCTL
 152static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 153                  void __user *buffer, size_t *lenp, loff_t *ppos);
 154static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
 155                               void __user *buffer, size_t *lenp, loff_t *ppos);
 156#endif
 157
 158static struct ctl_table root_table[];
 159static struct ctl_table_header root_table_header =
 160        { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 161
 162static struct ctl_table kern_table[];
 163static struct ctl_table vm_table[];
 164static struct ctl_table fs_table[];
 165static struct ctl_table debug_table[];
 166static struct ctl_table dev_table[];
 167extern struct ctl_table random_table[];
 168#ifdef CONFIG_INOTIFY_USER
 169extern struct ctl_table inotify_table[];
 170#endif
 171
 172#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 173int sysctl_legacy_va_layout;
 174#endif
 175
 176extern int prove_locking;
 177extern int lock_stat;
 178
 179/* The default sysctl tables: */
 180
 181static struct ctl_table root_table[] = {
 182        {
 183                .ctl_name       = CTL_KERN,
 184                .procname       = "kernel",
 185                .mode           = 0555,
 186                .child          = kern_table,
 187        },
 188        {
 189                .ctl_name       = CTL_VM,
 190                .procname       = "vm",
 191                .mode           = 0555,
 192                .child          = vm_table,
 193        },
 194#ifdef CONFIG_NET
 195        {
 196                .ctl_name       = CTL_NET,
 197                .procname       = "net",
 198                .mode           = 0555,
 199                .child          = net_table,
 200        },
 201#endif
 202        {
 203                .ctl_name       = CTL_FS,
 204                .procname       = "fs",
 205                .mode           = 0555,
 206                .child          = fs_table,
 207        },
 208        {
 209                .ctl_name       = CTL_DEBUG,
 210                .procname       = "debug",
 211                .mode           = 0555,
 212                .child          = debug_table,
 213        },
 214        {
 215                .ctl_name       = CTL_DEV,
 216                .procname       = "dev",
 217                .mode           = 0555,
 218                .child          = dev_table,
 219        },
 220/*
 221 * NOTE: do not add new entries to this table unless you have read
 222 * Documentation/sysctl/ctl_unnumbered.txt
 223 */
 224        { .ctl_name = 0 }
 225};
 226
 227#ifdef CONFIG_SCHED_DEBUG
 228static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 229static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 230static int min_wakeup_granularity_ns;                   /* 0 usecs */
 231static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 232#endif
 233
 234static struct ctl_table kern_table[] = {
 235#ifdef CONFIG_SCHED_DEBUG
 236        {
 237                .ctl_name       = CTL_UNNUMBERED,
 238                .procname       = "sched_min_granularity_ns",
 239                .data           = &sysctl_sched_min_granularity,
 240                .maxlen         = sizeof(unsigned int),
 241                .mode           = 0644,
 242                .proc_handler   = &sched_nr_latency_handler,
 243                .strategy       = &sysctl_intvec,
 244                .extra1         = &min_sched_granularity_ns,
 245                .extra2         = &max_sched_granularity_ns,
 246        },
 247        {
 248                .ctl_name       = CTL_UNNUMBERED,
 249                .procname       = "sched_latency_ns",
 250                .data           = &sysctl_sched_latency,
 251                .maxlen         = sizeof(unsigned int),
 252                .mode           = 0644,
 253                .proc_handler   = &sched_nr_latency_handler,
 254                .strategy       = &sysctl_intvec,
 255                .extra1         = &min_sched_granularity_ns,
 256                .extra2         = &max_sched_granularity_ns,
 257        },
 258        {
 259                .ctl_name       = CTL_UNNUMBERED,
 260                .procname       = "sched_wakeup_granularity_ns",
 261                .data           = &sysctl_sched_wakeup_granularity,
 262                .maxlen         = sizeof(unsigned int),
 263                .mode           = 0644,
 264                .proc_handler   = &proc_dointvec_minmax,
 265                .strategy       = &sysctl_intvec,
 266                .extra1         = &min_wakeup_granularity_ns,
 267                .extra2         = &max_wakeup_granularity_ns,
 268        },
 269        {
 270                .ctl_name       = CTL_UNNUMBERED,
 271                .procname       = "sched_batch_wakeup_granularity_ns",
 272                .data           = &sysctl_sched_batch_wakeup_granularity,
 273                .maxlen         = sizeof(unsigned int),
 274                .mode           = 0644,
 275                .proc_handler   = &proc_dointvec_minmax,
 276                .strategy       = &sysctl_intvec,
 277                .extra1         = &min_wakeup_granularity_ns,
 278                .extra2         = &max_wakeup_granularity_ns,
 279        },
 280        {
 281                .ctl_name       = CTL_UNNUMBERED,
 282                .procname       = "sched_child_runs_first",
 283                .data           = &sysctl_sched_child_runs_first,
 284                .maxlen         = sizeof(unsigned int),
 285                .mode           = 0644,
 286                .proc_handler   = &proc_dointvec,
 287        },
 288        {
 289                .ctl_name       = CTL_UNNUMBERED,
 290                .procname       = "sched_features",
 291                .data           = &sysctl_sched_features,
 292                .maxlen         = sizeof(unsigned int),
 293                .mode           = 0644,
 294                .proc_handler   = &proc_dointvec,
 295        },
 296        {
 297                .ctl_name       = CTL_UNNUMBERED,
 298                .procname       = "sched_migration_cost",
 299                .data           = &sysctl_sched_migration_cost,
 300                .maxlen         = sizeof(unsigned int),
 301                .mode           = 0644,
 302                .proc_handler   = &proc_dointvec,
 303        },
 304        {
 305                .ctl_name       = CTL_UNNUMBERED,
 306                .procname       = "sched_nr_migrate",
 307                .data           = &sysctl_sched_nr_migrate,
 308                .maxlen         = sizeof(unsigned int),
 309                .mode           = 644,
 310                .proc_handler   = &proc_dointvec,
 311        },
 312#endif
 313        {
 314                .ctl_name       = CTL_UNNUMBERED,
 315                .procname       = "sched_compat_yield",
 316                .data           = &sysctl_sched_compat_yield,
 317                .maxlen         = sizeof(unsigned int),
 318                .mode           = 0644,
 319                .proc_handler   = &proc_dointvec,
 320        },
 321#ifdef CONFIG_PROVE_LOCKING
 322        {
 323                .ctl_name       = CTL_UNNUMBERED,
 324                .procname       = "prove_locking",
 325                .data           = &prove_locking,
 326                .maxlen         = sizeof(int),
 327                .mode           = 0644,
 328                .proc_handler   = &proc_dointvec,
 329        },
 330#endif
 331#ifdef CONFIG_LOCK_STAT
 332        {
 333                .ctl_name       = CTL_UNNUMBERED,
 334                .procname       = "lock_stat",
 335                .data           = &lock_stat,
 336                .maxlen         = sizeof(int),
 337                .mode           = 0644,
 338                .proc_handler   = &proc_dointvec,
 339        },
 340#endif
 341        {
 342                .ctl_name       = KERN_PANIC,
 343                .procname       = "panic",
 344                .data           = &panic_timeout,
 345                .maxlen         = sizeof(int),
 346                .mode           = 0644,
 347                .proc_handler   = &proc_dointvec,
 348        },
 349        {
 350                .ctl_name       = KERN_CORE_USES_PID,
 351                .procname       = "core_uses_pid",
 352                .data           = &core_uses_pid,
 353                .maxlen         = sizeof(int),
 354                .mode           = 0644,
 355                .proc_handler   = &proc_dointvec,
 356        },
 357#ifdef CONFIG_AUDITSYSCALL
 358        {
 359                .ctl_name       = CTL_UNNUMBERED,
 360                .procname       = "audit_argv_kb",
 361                .data           = &audit_argv_kb,
 362                .maxlen         = sizeof(int),
 363                .mode           = 0644,
 364                .proc_handler   = &proc_dointvec,
 365        },
 366#endif
 367        {
 368                .ctl_name       = KERN_CORE_PATTERN,
 369                .procname       = "core_pattern",
 370                .data           = core_pattern,
 371                .maxlen         = CORENAME_MAX_SIZE,
 372                .mode           = 0644,
 373                .proc_handler   = &proc_dostring,
 374                .strategy       = &sysctl_string,
 375        },
 376#ifdef CONFIG_PROC_SYSCTL
 377        {
 378                .procname       = "tainted",
 379                .data           = &tainted,
 380                .maxlen         = sizeof(int),
 381                .mode           = 0644,
 382                .proc_handler   = &proc_dointvec_taint,
 383        },
 384#endif
 385#ifdef CONFIG_SECURITY_CAPABILITIES
 386        {
 387                .procname       = "cap-bound",
 388                .data           = &cap_bset,
 389                .maxlen         = sizeof(kernel_cap_t),
 390                .mode           = 0600,
 391                .proc_handler   = &proc_dointvec_bset,
 392        },
 393#endif /* def CONFIG_SECURITY_CAPABILITIES */
 394#ifdef CONFIG_BLK_DEV_INITRD
 395        {
 396                .ctl_name       = KERN_REALROOTDEV,
 397                .procname       = "real-root-dev",
 398                .data           = &real_root_dev,
 399                .maxlen         = sizeof(int),
 400                .mode           = 0644,
 401                .proc_handler   = &proc_dointvec,
 402        },
 403#endif
 404        {
 405                .ctl_name       = CTL_UNNUMBERED,
 406                .procname       = "print-fatal-signals",
 407                .data           = &print_fatal_signals,
 408                .maxlen         = sizeof(int),
 409                .mode           = 0644,
 410                .proc_handler   = &proc_dointvec,
 411        },
 412#ifdef __sparc__
 413        {
 414                .ctl_name       = KERN_SPARC_REBOOT,
 415                .procname       = "reboot-cmd",
 416                .data           = reboot_command,
 417                .maxlen         = 256,
 418                .mode           = 0644,
 419                .proc_handler   = &proc_dostring,
 420                .strategy       = &sysctl_string,
 421        },
 422        {
 423                .ctl_name       = KERN_SPARC_STOP_A,
 424                .procname       = "stop-a",
 425                .data           = &stop_a_enabled,
 426                .maxlen         = sizeof (int),
 427                .mode           = 0644,
 428                .proc_handler   = &proc_dointvec,
 429        },
 430        {
 431                .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 432                .procname       = "scons-poweroff",
 433                .data           = &scons_pwroff,
 434                .maxlen         = sizeof (int),
 435                .mode           = 0644,
 436                .proc_handler   = &proc_dointvec,
 437        },
 438#endif
 439#ifdef __hppa__
 440        {
 441                .ctl_name       = KERN_HPPA_PWRSW,
 442                .procname       = "soft-power",
 443                .data           = &pwrsw_enabled,
 444                .maxlen         = sizeof (int),
 445                .mode           = 0644,
 446                .proc_handler   = &proc_dointvec,
 447        },
 448        {
 449                .ctl_name       = KERN_HPPA_UNALIGNED,
 450                .procname       = "unaligned-trap",
 451                .data           = &unaligned_enabled,
 452                .maxlen         = sizeof (int),
 453                .mode           = 0644,
 454                .proc_handler   = &proc_dointvec,
 455        },
 456#endif
 457        {
 458                .ctl_name       = KERN_CTLALTDEL,
 459                .procname       = "ctrl-alt-del",
 460                .data           = &C_A_D,
 461                .maxlen         = sizeof(int),
 462                .mode           = 0644,
 463                .proc_handler   = &proc_dointvec,
 464        },
 465        {
 466                .ctl_name       = KERN_PRINTK,
 467                .procname       = "printk",
 468                .data           = &console_loglevel,
 469                .maxlen         = 4*sizeof(int),
 470                .mode           = 0644,
 471                .proc_handler   = &proc_dointvec,
 472        },
 473#ifdef CONFIG_KMOD
 474        {
 475                .ctl_name       = KERN_MODPROBE,
 476                .procname       = "modprobe",
 477                .data           = &modprobe_path,
 478                .maxlen         = KMOD_PATH_LEN,
 479                .mode           = 0644,
 480                .proc_handler   = &proc_dostring,
 481                .strategy       = &sysctl_string,
 482        },
 483#endif
 484#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 485        {
 486                .ctl_name       = KERN_HOTPLUG,
 487                .procname       = "hotplug",
 488                .data           = &uevent_helper,
 489                .maxlen         = UEVENT_HELPER_PATH_LEN,
 490                .mode           = 0644,
 491                .proc_handler   = &proc_dostring,
 492                .strategy       = &sysctl_string,
 493        },
 494#endif
 495#ifdef CONFIG_CHR_DEV_SG
 496        {
 497                .ctl_name       = KERN_SG_BIG_BUFF,
 498                .procname       = "sg-big-buff",
 499                .data           = &sg_big_buff,
 500                .maxlen         = sizeof (int),
 501                .mode           = 0444,
 502                .proc_handler   = &proc_dointvec,
 503        },
 504#endif
 505#ifdef CONFIG_BSD_PROCESS_ACCT
 506        {
 507                .ctl_name       = KERN_ACCT,
 508                .procname       = "acct",
 509                .data           = &acct_parm,
 510                .maxlen         = 3*sizeof(int),
 511                .mode           = 0644,
 512                .proc_handler   = &proc_dointvec,
 513        },
 514#endif
 515#ifdef CONFIG_MAGIC_SYSRQ
 516        {
 517                .ctl_name       = KERN_SYSRQ,
 518                .procname       = "sysrq",
 519                .data           = &__sysrq_enabled,
 520                .maxlen         = sizeof (int),
 521                .mode           = 0644,
 522                .proc_handler   = &proc_dointvec,
 523        },
 524#endif
 525#ifdef CONFIG_PROC_SYSCTL
 526        {
 527                .procname       = "cad_pid",
 528                .data           = NULL,
 529                .maxlen         = sizeof (int),
 530                .mode           = 0600,
 531                .proc_handler   = &proc_do_cad_pid,
 532        },
 533#endif
 534        {
 535                .ctl_name       = KERN_MAX_THREADS,
 536                .procname       = "threads-max",
 537                .data           = &max_threads,
 538                .maxlen         = sizeof(int),
 539                .mode           = 0644,
 540                .proc_handler   = &proc_dointvec,
 541        },
 542        {
 543                .ctl_name       = KERN_RANDOM,
 544                .procname       = "random",
 545                .mode           = 0555,
 546                .child          = random_table,
 547        },
 548        {
 549                .ctl_name       = KERN_OVERFLOWUID,
 550                .procname       = "overflowuid",
 551                .data           = &overflowuid,
 552                .maxlen         = sizeof(int),
 553                .mode           = 0644,
 554                .proc_handler   = &proc_dointvec_minmax,
 555                .strategy       = &sysctl_intvec,
 556                .extra1         = &minolduid,
 557                .extra2         = &maxolduid,
 558        },
 559        {
 560                .ctl_name       = KERN_OVERFLOWGID,
 561                .procname       = "overflowgid",
 562                .data           = &overflowgid,
 563                .maxlen         = sizeof(int),
 564                .mode           = 0644,
 565                .proc_handler   = &proc_dointvec_minmax,
 566                .strategy       = &sysctl_intvec,
 567                .extra1         = &minolduid,
 568                .extra2         = &maxolduid,
 569        },
 570#ifdef CONFIG_S390
 571#ifdef CONFIG_MATHEMU
 572        {
 573                .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 574                .procname       = "ieee_emulation_warnings",
 575                .data           = &sysctl_ieee_emulation_warnings,
 576                .maxlen         = sizeof(int),
 577                .mode           = 0644,
 578                .proc_handler   = &proc_dointvec,
 579        },
 580#endif
 581#ifdef CONFIG_NO_IDLE_HZ
 582        {
 583                .ctl_name       = KERN_HZ_TIMER,
 584                .procname       = "hz_timer",
 585                .data           = &sysctl_hz_timer,
 586                .maxlen         = sizeof(int),
 587                .mode           = 0644,
 588                .proc_handler   = &proc_dointvec,
 589        },
 590#endif
 591        {
 592                .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 593                .procname       = "userprocess_debug",
 594                .data           = &sysctl_userprocess_debug,
 595                .maxlen         = sizeof(int),
 596                .mode           = 0644,
 597                .proc_handler   = &proc_dointvec,
 598        },
 599#endif
 600        {
 601                .ctl_name       = KERN_PIDMAX,
 602                .procname       = "pid_max",
 603                .data           = &pid_max,
 604                .maxlen         = sizeof (int),
 605                .mode           = 0644,
 606                .proc_handler   = &proc_dointvec_minmax,
 607                .strategy       = sysctl_intvec,
 608                .extra1         = &pid_max_min,
 609                .extra2         = &pid_max_max,
 610        },
 611        {
 612                .ctl_name       = KERN_PANIC_ON_OOPS,
 613                .procname       = "panic_on_oops",
 614                .data           = &panic_on_oops,
 615                .maxlen         = sizeof(int),
 616                .mode           = 0644,
 617                .proc_handler   = &proc_dointvec,
 618        },
 619        {
 620                .ctl_name       = KERN_PRINTK_RATELIMIT,
 621                .procname       = "printk_ratelimit",
 622                .data           = &printk_ratelimit_jiffies,
 623                .maxlen         = sizeof(int),
 624                .mode           = 0644,
 625                .proc_handler   = &proc_dointvec_jiffies,
 626                .strategy       = &sysctl_jiffies,
 627        },
 628        {
 629                .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 630                .procname       = "printk_ratelimit_burst",
 631                .data           = &printk_ratelimit_burst,
 632                .maxlen         = sizeof(int),
 633                .mode           = 0644,
 634                .proc_handler   = &proc_dointvec,
 635        },
 636        {
 637                .ctl_name       = KERN_NGROUPS_MAX,
 638                .procname       = "ngroups_max",
 639                .data           = &ngroups_max,
 640                .maxlen         = sizeof (int),
 641                .mode           = 0444,
 642                .proc_handler   = &proc_dointvec,
 643        },
 644#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 645        {
 646                .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 647                .procname       = "unknown_nmi_panic",
 648                .data           = &unknown_nmi_panic,
 649                .maxlen         = sizeof (int),
 650                .mode           = 0644,
 651                .proc_handler   = &proc_dointvec,
 652        },
 653        {
 654                .procname       = "nmi_watchdog",
 655                .data           = &nmi_watchdog_enabled,
 656                .maxlen         = sizeof (int),
 657                .mode           = 0644,
 658                .proc_handler   = &proc_nmi_enabled,
 659        },
 660#endif
 661#if defined(CONFIG_X86)
 662        {
 663                .ctl_name       = KERN_PANIC_ON_NMI,
 664                .procname       = "panic_on_unrecovered_nmi",
 665                .data           = &panic_on_unrecovered_nmi,
 666                .maxlen         = sizeof(int),
 667                .mode           = 0644,
 668                .proc_handler   = &proc_dointvec,
 669        },
 670        {
 671                .ctl_name       = KERN_BOOTLOADER_TYPE,
 672                .procname       = "bootloader_type",
 673                .data           = &bootloader_type,
 674                .maxlen         = sizeof (int),
 675                .mode           = 0444,
 676                .proc_handler   = &proc_dointvec,
 677        },
 678        {
 679                .ctl_name       = CTL_UNNUMBERED,
 680                .procname       = "kstack_depth_to_print",
 681                .data           = &kstack_depth_to_print,
 682                .maxlen         = sizeof(int),
 683                .mode           = 0644,
 684                .proc_handler   = &proc_dointvec,
 685        },
 686#endif
 687#if defined(CONFIG_MMU)
 688        {
 689                .ctl_name       = KERN_RANDOMIZE,
 690                .procname       = "randomize_va_space",
 691                .data           = &randomize_va_space,
 692                .maxlen         = sizeof(int),
 693                .mode           = 0644,
 694                .proc_handler   = &proc_dointvec,
 695        },
 696#endif
 697#if defined(CONFIG_S390) && defined(CONFIG_SMP)
 698        {
 699                .ctl_name       = KERN_SPIN_RETRY,
 700                .procname       = "spin_retry",
 701                .data           = &spin_retry,
 702                .maxlen         = sizeof (int),
 703                .mode           = 0644,
 704                .proc_handler   = &proc_dointvec,
 705        },
 706#endif
 707#if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 708        {
 709                .procname       = "acpi_video_flags",
 710                .data           = &acpi_realmode_flags,
 711                .maxlen         = sizeof (unsigned long),
 712                .mode           = 0644,
 713                .proc_handler   = &proc_doulongvec_minmax,
 714        },
 715#endif
 716#ifdef CONFIG_IA64
 717        {
 718                .ctl_name       = KERN_IA64_UNALIGNED,
 719                .procname       = "ignore-unaligned-usertrap",
 720                .data           = &no_unaligned_warning,
 721                .maxlen         = sizeof (int),
 722                .mode           = 0644,
 723                .proc_handler   = &proc_dointvec,
 724        },
 725#endif
 726#ifdef CONFIG_DETECT_SOFTLOCKUP
 727        {
 728                .ctl_name       = CTL_UNNUMBERED,
 729                .procname       = "softlockup_thresh",
 730                .data           = &softlockup_thresh,
 731                .maxlen         = sizeof(int),
 732                .mode           = 0644,
 733                .proc_handler   = &proc_dointvec_minmax,
 734                .strategy       = &sysctl_intvec,
 735                .extra1         = &one,
 736                .extra2         = &sixty,
 737        },
 738#endif
 739#ifdef CONFIG_COMPAT
 740        {
 741                .ctl_name       = KERN_COMPAT_LOG,
 742                .procname       = "compat-log",
 743                .data           = &compat_log,
 744                .maxlen         = sizeof (int),
 745                .mode           = 0644,
 746                .proc_handler   = &proc_dointvec,
 747        },
 748#endif
 749#ifdef CONFIG_RT_MUTEXES
 750        {
 751                .ctl_name       = KERN_MAX_LOCK_DEPTH,
 752                .procname       = "max_lock_depth",
 753                .data           = &max_lock_depth,
 754                .maxlen         = sizeof(int),
 755                .mode           = 0644,
 756                .proc_handler   = &proc_dointvec,
 757        },
 758#endif
 759#ifdef CONFIG_PROC_FS
 760        {
 761                .ctl_name       = CTL_UNNUMBERED,
 762                .procname       = "maps_protect",
 763                .data           = &maps_protect,
 764                .maxlen         = sizeof(int),
 765                .mode           = 0644,
 766                .proc_handler   = &proc_dointvec,
 767        },
 768#endif
 769        {
 770                .ctl_name       = CTL_UNNUMBERED,
 771                .procname       = "poweroff_cmd",
 772                .data           = &poweroff_cmd,
 773                .maxlen         = POWEROFF_CMD_PATH_LEN,
 774                .mode           = 0644,
 775                .proc_handler   = &proc_dostring,
 776                .strategy       = &sysctl_string,
 777        },
 778/*
 779 * NOTE: do not add new entries to this table unless you have read
 780 * Documentation/sysctl/ctl_unnumbered.txt
 781 */
 782        { .ctl_name = 0 }
 783};
 784
 785static struct ctl_table vm_table[] = {
 786        {
 787                .ctl_name       = VM_OVERCOMMIT_MEMORY,
 788                .procname       = "overcommit_memory",
 789                .data           = &sysctl_overcommit_memory,
 790                .maxlen         = sizeof(sysctl_overcommit_memory),
 791                .mode           = 0644,
 792                .proc_handler   = &proc_dointvec,
 793        },
 794        {
 795                .ctl_name       = VM_PANIC_ON_OOM,
 796                .procname       = "panic_on_oom",
 797                .data           = &sysctl_panic_on_oom,
 798                .maxlen         = sizeof(sysctl_panic_on_oom),
 799                .mode           = 0644,
 800                .proc_handler   = &proc_dointvec,
 801        },
 802        {
 803                .ctl_name       = CTL_UNNUMBERED,
 804                .procname       = "oom_kill_allocating_task",
 805                .data           = &sysctl_oom_kill_allocating_task,
 806                .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 807                .mode           = 0644,
 808                .proc_handler   = &proc_dointvec,
 809        },
 810        {
 811                .ctl_name       = VM_OVERCOMMIT_RATIO,
 812                .procname       = "overcommit_ratio",
 813                .data           = &sysctl_overcommit_ratio,
 814                .maxlen         = sizeof(sysctl_overcommit_ratio),
 815                .mode           = 0644,
 816                .proc_handler   = &proc_dointvec,
 817        },
 818        {
 819                .ctl_name       = VM_PAGE_CLUSTER,
 820                .procname       = "page-cluster", 
 821                .data           = &page_cluster,
 822                .maxlen         = sizeof(int),
 823                .mode           = 0644,
 824                .proc_handler   = &proc_dointvec,
 825        },
 826        {
 827                .ctl_name       = VM_DIRTY_BACKGROUND,
 828                .procname       = "dirty_background_ratio",
 829                .data           = &dirty_background_ratio,
 830                .maxlen         = sizeof(dirty_background_ratio),
 831                .mode           = 0644,
 832                .proc_handler   = &proc_dointvec_minmax,
 833                .strategy       = &sysctl_intvec,
 834                .extra1         = &zero,
 835                .extra2         = &one_hundred,
 836        },
 837        {
 838                .ctl_name       = VM_DIRTY_RATIO,
 839                .procname       = "dirty_ratio",
 840                .data           = &vm_dirty_ratio,
 841                .maxlen         = sizeof(vm_dirty_ratio),
 842                .mode           = 0644,
 843                .proc_handler   = &dirty_ratio_handler,
 844                .strategy       = &sysctl_intvec,
 845                .extra1         = &zero,
 846                .extra2         = &one_hundred,
 847        },
 848        {
 849                .procname       = "dirty_writeback_centisecs",
 850                .data           = &dirty_writeback_interval,
 851                .maxlen         = sizeof(dirty_writeback_interval),
 852                .mode           = 0644,
 853                .proc_handler   = &dirty_writeback_centisecs_handler,
 854        },
 855        {
 856                .procname       = "dirty_expire_centisecs",
 857                .data           = &dirty_expire_interval,
 858                .maxlen         = sizeof(dirty_expire_interval),
 859                .mode           = 0644,
 860                .proc_handler   = &proc_dointvec_userhz_jiffies,
 861        },
 862        {
 863                .ctl_name       = VM_NR_PDFLUSH_THREADS,
 864                .procname       = "nr_pdflush_threads",
 865                .data           = &nr_pdflush_threads,
 866                .maxlen         = sizeof nr_pdflush_threads,
 867                .mode           = 0444 /* read-only*/,
 868                .proc_handler   = &proc_dointvec,
 869        },
 870        {
 871                .ctl_name       = VM_SWAPPINESS,
 872                .procname       = "swappiness",
 873                .data           = &vm_swappiness,
 874                .maxlen         = sizeof(vm_swappiness),
 875                .mode           = 0644,
 876                .proc_handler   = &proc_dointvec_minmax,
 877                .strategy       = &sysctl_intvec,
 878                .extra1         = &zero,
 879                .extra2         = &one_hundred,
 880        },
 881#ifdef CONFIG_HUGETLB_PAGE
 882         {
 883                .procname       = "nr_hugepages",
 884                .data           = &max_huge_pages,
 885                .maxlen         = sizeof(unsigned long),
 886                .mode           = 0644,
 887                .proc_handler   = &hugetlb_sysctl_handler,
 888                .extra1         = (void *)&hugetlb_zero,
 889                .extra2         = (void *)&hugetlb_infinity,
 890         },
 891         {
 892                .ctl_name       = VM_HUGETLB_GROUP,
 893                .procname       = "hugetlb_shm_group",
 894                .data           = &sysctl_hugetlb_shm_group,
 895                .maxlen         = sizeof(gid_t),
 896                .mode           = 0644,
 897                .proc_handler   = &proc_dointvec,
 898         },
 899         {
 900                .ctl_name       = CTL_UNNUMBERED,
 901                .procname       = "hugepages_treat_as_movable",
 902                .data           = &hugepages_treat_as_movable,
 903                .maxlen         = sizeof(int),
 904                .mode           = 0644,
 905                .proc_handler   = &hugetlb_treat_movable_handler,
 906        },
 907        {
 908                .ctl_name       = CTL_UNNUMBERED,
 909                .procname       = "nr_overcommit_hugepages",
 910                .data           = &nr_overcommit_huge_pages,
 911                .maxlen         = sizeof(nr_overcommit_huge_pages),
 912                .mode           = 0644,
 913                .proc_handler   = &proc_doulongvec_minmax,
 914        },
 915#endif
 916        {
 917                .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 918                .procname       = "lowmem_reserve_ratio",
 919                .data           = &sysctl_lowmem_reserve_ratio,
 920                .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 921                .mode           = 0644,
 922                .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 923                .strategy       = &sysctl_intvec,
 924        },
 925        {
 926                .ctl_name       = VM_DROP_PAGECACHE,
 927                .procname       = "drop_caches",
 928                .data           = &sysctl_drop_caches,
 929                .maxlen         = sizeof(int),
 930                .mode           = 0644,
 931                .proc_handler   = drop_caches_sysctl_handler,
 932                .strategy       = &sysctl_intvec,
 933        },
 934        {
 935                .ctl_name       = VM_MIN_FREE_KBYTES,
 936                .procname       = "min_free_kbytes",
 937                .data           = &min_free_kbytes,
 938                .maxlen         = sizeof(min_free_kbytes),
 939                .mode           = 0644,
 940                .proc_handler   = &min_free_kbytes_sysctl_handler,
 941                .strategy       = &sysctl_intvec,
 942                .extra1         = &zero,
 943        },
 944        {
 945                .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 946                .procname       = "percpu_pagelist_fraction",
 947                .data           = &percpu_pagelist_fraction,
 948                .maxlen         = sizeof(percpu_pagelist_fraction),
 949                .mode           = 0644,
 950                .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 951                .strategy       = &sysctl_intvec,
 952                .extra1         = &min_percpu_pagelist_fract,
 953        },
 954#ifdef CONFIG_MMU
 955        {
 956                .ctl_name       = VM_MAX_MAP_COUNT,
 957                .procname       = "max_map_count",
 958                .data           = &sysctl_max_map_count,
 959                .maxlen         = sizeof(sysctl_max_map_count),
 960                .mode           = 0644,
 961                .proc_handler   = &proc_dointvec
 962        },
 963#endif
 964        {
 965                .ctl_name       = VM_LAPTOP_MODE,
 966                .procname       = "laptop_mode",
 967                .data           = &laptop_mode,
 968                .maxlen         = sizeof(laptop_mode),
 969                .mode           = 0644,
 970                .proc_handler   = &proc_dointvec_jiffies,
 971                .strategy       = &sysctl_jiffies,
 972        },
 973        {
 974                .ctl_name       = VM_BLOCK_DUMP,
 975                .procname       = "block_dump",
 976                .data           = &block_dump,
 977                .maxlen         = sizeof(block_dump),
 978                .mode           = 0644,
 979                .proc_handler   = &proc_dointvec,
 980                .strategy       = &sysctl_intvec,
 981                .extra1         = &zero,
 982        },
 983        {
 984                .ctl_name       = VM_VFS_CACHE_PRESSURE,
 985                .procname       = "vfs_cache_pressure",
 986                .data           = &sysctl_vfs_cache_pressure,
 987                .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 988                .mode           = 0644,
 989                .proc_handler   = &proc_dointvec,
 990                .strategy       = &sysctl_intvec,
 991                .extra1         = &zero,
 992        },
 993#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 994        {
 995                .ctl_name       = VM_LEGACY_VA_LAYOUT,
 996                .procname       = "legacy_va_layout",
 997                .data           = &sysctl_legacy_va_layout,
 998                .maxlen         = sizeof(sysctl_legacy_va_layout),
 999                .mode           = 0644,
1000                .proc_handler   = &proc_dointvec,
1001                .strategy       = &sysctl_intvec,
1002                .extra1         = &zero,
1003        },
1004#endif
1005#ifdef CONFIG_NUMA
1006        {
1007                .ctl_name       = VM_ZONE_RECLAIM_MODE,
1008                .procname       = "zone_reclaim_mode",
1009                .data           = &zone_reclaim_mode,
1010                .maxlen         = sizeof(zone_reclaim_mode),
1011                .mode           = 0644,
1012                .proc_handler   = &proc_dointvec,
1013                .strategy       = &sysctl_intvec,
1014                .extra1         = &zero,
1015        },
1016        {
1017                .ctl_name       = VM_MIN_UNMAPPED,
1018                .procname       = "min_unmapped_ratio",
1019                .data           = &sysctl_min_unmapped_ratio,
1020                .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1021                .mode           = 0644,
1022                .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1023                .strategy       = &sysctl_intvec,
1024                .extra1         = &zero,
1025                .extra2         = &one_hundred,
1026        },
1027        {
1028                .ctl_name       = VM_MIN_SLAB,
1029                .procname       = "min_slab_ratio",
1030                .data           = &sysctl_min_slab_ratio,
1031                .maxlen         = sizeof(sysctl_min_slab_ratio),
1032                .mode           = 0644,
1033                .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1034                .strategy       = &sysctl_intvec,
1035                .extra1         = &zero,
1036                .extra2         = &one_hundred,
1037        },
1038#endif
1039#ifdef CONFIG_SMP
1040        {
1041                .ctl_name       = CTL_UNNUMBERED,
1042                .procname       = "stat_interval",
1043                .data           = &sysctl_stat_interval,
1044                .maxlen         = sizeof(sysctl_stat_interval),
1045                .mode           = 0644,
1046                .proc_handler   = &proc_dointvec_jiffies,
1047                .strategy       = &sysctl_jiffies,
1048        },
1049#endif
1050#ifdef CONFIG_SECURITY
1051        {
1052                .ctl_name       = CTL_UNNUMBERED,
1053                .procname       = "mmap_min_addr",
1054                .data           = &mmap_min_addr,
1055                .maxlen         = sizeof(unsigned long),
1056                .mode           = 0644,
1057                .proc_handler   = &proc_doulongvec_minmax,
1058        },
1059#endif
1060#ifdef CONFIG_NUMA
1061        {
1062                .ctl_name       = CTL_UNNUMBERED,
1063                .procname       = "numa_zonelist_order",
1064                .data           = &numa_zonelist_order,
1065                .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1066                .mode           = 0644,
1067                .proc_handler   = &numa_zonelist_order_handler,
1068                .strategy       = &sysctl_string,
1069        },
1070#endif
1071#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1072   (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1073        {
1074                .ctl_name       = VM_VDSO_ENABLED,
1075                .procname       = "vdso_enabled",
1076                .data           = &vdso_enabled,
1077                .maxlen         = sizeof(vdso_enabled),
1078                .mode           = 0644,
1079                .proc_handler   = &proc_dointvec,
1080                .strategy       = &sysctl_intvec,
1081                .extra1         = &zero,
1082        },
1083#endif
1084/*
1085 * NOTE: do not add new entries to this table unless you have read
1086 * Documentation/sysctl/ctl_unnumbered.txt
1087 */
1088        { .ctl_name = 0 }
1089};
1090
1091#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1092static struct ctl_table binfmt_misc_table[] = {
1093        { .ctl_name = 0 }
1094};
1095#endif
1096
1097static struct ctl_table fs_table[] = {
1098        {
1099                .ctl_name       = FS_NRINODE,
1100                .procname       = "inode-nr",
1101                .data           = &inodes_stat,
1102                .maxlen         = 2*sizeof(int),
1103                .mode           = 0444,
1104                .proc_handler   = &proc_dointvec,
1105        },
1106        {
1107                .ctl_name       = FS_STATINODE,
1108                .procname       = "inode-state",
1109                .data           = &inodes_stat,
1110                .maxlen         = 7*sizeof(int),
1111                .mode           = 0444,
1112                .proc_handler   = &proc_dointvec,
1113        },
1114        {
1115                .procname       = "file-nr",
1116                .data           = &files_stat,
1117                .maxlen         = 3*sizeof(int),
1118                .mode           = 0444,
1119                .proc_handler   = &proc_nr_files,
1120        },
1121        {
1122                .ctl_name       = FS_MAXFILE,
1123                .procname       = "file-max",
1124                .data           = &files_stat.max_files,
1125                .maxlen         = sizeof(int),
1126                .mode           = 0644,
1127                .proc_handler   = &proc_dointvec,
1128        },
1129        {
1130                .ctl_name       = FS_DENTRY,
1131                .procname       = "dentry-state",
1132                .data           = &dentry_stat,
1133                .maxlen         = 6*sizeof(int),
1134                .mode           = 0444,
1135                .proc_handler   = &proc_dointvec,
1136        },
1137        {
1138                .ctl_name       = FS_OVERFLOWUID,
1139                .procname       = "overflowuid",
1140                .data           = &fs_overflowuid,
1141                .maxlen         = sizeof(int),
1142                .mode           = 0644,
1143                .proc_handler   = &proc_dointvec_minmax,
1144                .strategy       = &sysctl_intvec,
1145                .extra1         = &minolduid,
1146                .extra2         = &maxolduid,
1147        },
1148        {
1149                .ctl_name       = FS_OVERFLOWGID,
1150                .procname       = "overflowgid",
1151                .data           = &fs_overflowgid,
1152                .maxlen         = sizeof(int),
1153                .mode           = 0644,
1154                .proc_handler   = &proc_dointvec_minmax,
1155                .strategy       = &sysctl_intvec,
1156                .extra1         = &minolduid,
1157                .extra2         = &maxolduid,
1158        },
1159        {
1160                .ctl_name       = FS_LEASES,
1161                .procname       = "leases-enable",
1162                .data           = &leases_enable,
1163                .maxlen         = sizeof(int),
1164                .mode           = 0644,
1165                .proc_handler   = &proc_dointvec,
1166        },
1167#ifdef CONFIG_DNOTIFY
1168        {
1169                .ctl_name       = FS_DIR_NOTIFY,
1170                .procname       = "dir-notify-enable",
1171                .data           = &dir_notify_enable,
1172                .maxlen         = sizeof(int),
1173                .mode           = 0644,
1174                .proc_handler   = &proc_dointvec,
1175        },
1176#endif
1177#ifdef CONFIG_MMU
1178        {
1179                .ctl_name       = FS_LEASE_TIME,
1180                .procname       = "lease-break-time",
1181                .data           = &lease_break_time,
1182                .maxlen         = sizeof(int),
1183                .mode           = 0644,
1184                .proc_handler   = &proc_dointvec_minmax,
1185                .strategy       = &sysctl_intvec,
1186                .extra1         = &zero,
1187                .extra2         = &two,
1188        },
1189        {
1190                .procname       = "aio-nr",
1191                .data           = &aio_nr,
1192                .maxlen         = sizeof(aio_nr),
1193                .mode           = 0444,
1194                .proc_handler   = &proc_doulongvec_minmax,
1195        },
1196        {
1197                .procname       = "aio-max-nr",
1198                .data           = &aio_max_nr,
1199                .maxlen         = sizeof(aio_max_nr),
1200                .mode           = 0644,
1201                .proc_handler   = &proc_doulongvec_minmax,
1202        },
1203#ifdef CONFIG_INOTIFY_USER
1204        {
1205                .ctl_name       = FS_INOTIFY,
1206                .procname       = "inotify",
1207                .mode           = 0555,
1208                .child          = inotify_table,
1209        },
1210#endif  
1211#endif
1212        {
1213                .ctl_name       = KERN_SETUID_DUMPABLE,
1214                .procname       = "suid_dumpable",
1215                .data           = &suid_dumpable,
1216                .maxlen         = sizeof(int),
1217                .mode           = 0644,
1218                .proc_handler   = &proc_dointvec,
1219        },
1220#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1221        {
1222                .ctl_name       = CTL_UNNUMBERED,
1223                .procname       = "binfmt_misc",
1224                .mode           = 0555,
1225                .child          = binfmt_misc_table,
1226        },
1227#endif
1228/*
1229 * NOTE: do not add new entries to this table unless you have read
1230 * Documentation/sysctl/ctl_unnumbered.txt
1231 */
1232        { .ctl_name = 0 }
1233};
1234
1235static struct ctl_table debug_table[] = {
1236#if defined(CONFIG_X86) || defined(CONFIG_PPC)
1237        {
1238                .ctl_name       = CTL_UNNUMBERED,
1239                .procname       = "exception-trace",
1240                .data           = &show_unhandled_signals,
1241                .maxlen         = sizeof(int),
1242                .mode           = 0644,
1243                .proc_handler   = proc_dointvec
1244        },
1245#endif
1246        { .ctl_name = 0 }
1247};
1248
1249static struct ctl_table dev_table[] = {
1250        { .ctl_name = 0 }
1251};
1252
1253static DEFINE_SPINLOCK(sysctl_lock);
1254
1255/* called under sysctl_lock */
1256static int use_table(struct ctl_table_header *p)
1257{
1258        if (unlikely(p->unregistering))
1259                return 0;
1260        p->used++;
1261        return 1;
1262}
1263
1264/* called under sysctl_lock */
1265static void unuse_table(struct ctl_table_header *p)
1266{
1267        if (!--p->used)
1268                if (unlikely(p->unregistering))
1269                        complete(p->unregistering);
1270}
1271
1272/* called under sysctl_lock, will reacquire if has to wait */
1273static void start_unregistering(struct ctl_table_header *p)
1274{
1275        /*
1276         * if p->used is 0, nobody will ever touch that entry again;
1277         * we'll eliminate all paths to it before dropping sysctl_lock
1278         */
1279        if (unlikely(p->used)) {
1280                struct completion wait;
1281                init_completion(&wait);
1282                p->unregistering = &wait;
1283                spin_unlock(&sysctl_lock);
1284                wait_for_completion(&wait);
1285                spin_lock(&sysctl_lock);
1286        }
1287        /*
1288         * do not remove from the list until nobody holds it; walking the
1289         * list in do_sysctl() relies on that.
1290         */
1291        list_del_init(&p->ctl_entry);
1292}
1293
1294void sysctl_head_finish(struct ctl_table_header *head)
1295{
1296        if (!head)
1297                return;
1298        spin_lock(&sysctl_lock);
1299        unuse_table(head);
1300        spin_unlock(&sysctl_lock);
1301}
1302
1303struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1304{
1305        struct ctl_table_header *head;
1306        struct list_head *tmp;
1307        spin_lock(&sysctl_lock);
1308        if (prev) {
1309                tmp = &prev->ctl_entry;
1310                unuse_table(prev);
1311                goto next;
1312        }
1313        tmp = &root_table_header.ctl_entry;
1314        for (;;) {
1315                head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1316
1317                if (!use_table(head))
1318                        goto next;
1319                spin_unlock(&sysctl_lock);
1320                return head;
1321        next:
1322                tmp = tmp->next;
1323                if (tmp == &root_table_header.ctl_entry)
1324                        break;
1325        }
1326        spin_unlock(&sysctl_lock);
1327        return NULL;
1328}
1329
1330#ifdef CONFIG_SYSCTL_SYSCALL
1331int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1332               void __user *newval, size_t newlen)
1333{
1334        struct ctl_table_header *head;
1335        int error = -ENOTDIR;
1336
1337        if (nlen <= 0 || nlen >= CTL_MAXNAME)
1338                return -ENOTDIR;
1339        if (oldval) {
1340                int old_len;
1341                if (!oldlenp || get_user(old_len, oldlenp))
1342                        return -EFAULT;
1343        }
1344
1345        for (head = sysctl_head_next(NULL); head;
1346                        head = sysctl_head_next(head)) {
1347                error = parse_table(name, nlen, oldval, oldlenp, 
1348                                        newval, newlen, head->ctl_table);
1349                if (error != -ENOTDIR) {
1350                        sysctl_head_finish(head);
1351                        break;
1352                }
1353        }
1354        return error;
1355}
1356
1357asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1358{
1359        struct __sysctl_args tmp;
1360        int error;
1361
1362        if (copy_from_user(&tmp, args, sizeof(tmp)))
1363                return -EFAULT;
1364
1365        error = deprecated_sysctl_warning(&tmp);
1366        if (error)
1367                goto out;
1368
1369        lock_kernel();
1370        error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1371                          tmp.newval, tmp.newlen);
1372        unlock_kernel();
1373out:
1374        return error;
1375}
1376#endif /* CONFIG_SYSCTL_SYSCALL */
1377
1378/*
1379 * sysctl_perm does NOT grant the superuser all rights automatically, because
1380 * some sysctl variables are readonly even to root.
1381 */
1382
1383static int test_perm(int mode, int op)
1384{
1385        if (!current->euid)
1386                mode >>= 6;
1387        else if (in_egroup_p(0))
1388                mode >>= 3;
1389        if ((mode & op & 0007) == op)
1390                return 0;
1391        return -EACCES;
1392}
1393
1394int sysctl_perm(struct ctl_table *table, int op)
1395{
1396        int error;
1397        error = security_sysctl(table, op);
1398        if (error)
1399                return error;
1400        return test_perm(table->mode, op);
1401}
1402
1403#ifdef CONFIG_SYSCTL_SYSCALL
1404static int parse_table(int __user *name, int nlen,
1405                       void __user *oldval, size_t __user *oldlenp,
1406                       void __user *newval, size_t newlen,
1407                       struct ctl_table *table)
1408{
1409        int n;
1410repeat:
1411        if (!nlen)
1412                return -ENOTDIR;
1413        if (get_user(n, name))
1414                return -EFAULT;
1415        for ( ; table->ctl_name || table->procname; table++) {
1416                if (!table->ctl_name)
1417                        continue;
1418                if (n == table->ctl_name) {
1419                        int error;
1420                        if (table->child) {
1421                                if (sysctl_perm(table, 001))
1422                                        return -EPERM;
1423                                name++;
1424                                nlen--;
1425                                table = table->child;
1426                                goto repeat;
1427                        }
1428                        error = do_sysctl_strategy(table, name, nlen,
1429                                                   oldval, oldlenp,
1430                                                   newval, newlen);
1431                        return error;
1432                }
1433        }
1434        return -ENOTDIR;
1435}
1436
1437/* Perform the actual read/write of a sysctl table entry. */
1438int do_sysctl_strategy (struct ctl_table *table,
1439                        int __user *name, int nlen,
1440                        void __user *oldval, size_t __user *oldlenp,
1441                        void __user *newval, size_t newlen)
1442{
1443        int op = 0, rc;
1444
1445        if (oldval)
1446                op |= 004;
1447        if (newval) 
1448                op |= 002;
1449        if (sysctl_perm(table, op))
1450                return -EPERM;
1451
1452        if (table->strategy) {
1453                rc = table->strategy(table, name, nlen, oldval, oldlenp,
1454                                     newval, newlen);
1455                if (rc < 0)
1456                        return rc;
1457                if (rc > 0)
1458                        return 0;
1459        }
1460
1461        /* If there is no strategy routine, or if the strategy returns
1462         * zero, proceed with automatic r/w */
1463        if (table->data && table->maxlen) {
1464                rc = sysctl_data(table, name, nlen, oldval, oldlenp,
1465                                 newval, newlen);
1466                if (rc < 0)
1467                        return rc;
1468        }
1469        return 0;
1470}
1471#endif /* CONFIG_SYSCTL_SYSCALL */
1472
1473static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1474{
1475        for (; table->ctl_name || table->procname; table++) {
1476                table->parent = parent;
1477                if (table->child)
1478                        sysctl_set_parent(table, table->child);
1479        }
1480}
1481
1482static __init int sysctl_init(void)
1483{
1484        int err;
1485        sysctl_set_parent(NULL, root_table);
1486        err = sysctl_check_table(root_table);
1487        return 0;
1488}
1489
1490core_initcall(sysctl_init);
1491
1492/**
1493 * register_sysctl_table - register a sysctl hierarchy
1494 * @table: the top-level table structure
1495 *
1496 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1497 * array. An entry with a ctl_name of 0 terminates the table. 
1498 *
1499 * The members of the &struct ctl_table structure are used as follows:
1500 *
1501 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1502 *            must be unique within that level of sysctl
1503 *
1504 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1505 *            enter a sysctl file
1506 *
1507 * data - a pointer to data for use by proc_handler
1508 *
1509 * maxlen - the maximum size in bytes of the data
1510 *
1511 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1512 *
1513 * child - a pointer to the child sysctl table if this entry is a directory, or
1514 *         %NULL.
1515 *
1516 * proc_handler - the text handler routine (described below)
1517 *
1518 * strategy - the strategy routine (described below)
1519 *
1520 * de - for internal use by the sysctl routines
1521 *
1522 * extra1, extra2 - extra pointers usable by the proc handler routines
1523 *
1524 * Leaf nodes in the sysctl tree will be represented by a single file
1525 * under /proc; non-leaf nodes will be represented by directories.
1526 *
1527 * sysctl(2) can automatically manage read and write requests through
1528 * the sysctl table.  The data and maxlen fields of the ctl_table
1529 * struct enable minimal validation of the values being written to be
1530 * performed, and the mode field allows minimal authentication.
1531 *
1532 * More sophisticated management can be enabled by the provision of a
1533 * strategy routine with the table entry.  This will be called before
1534 * any automatic read or write of the data is performed.
1535 *
1536 * The strategy routine may return
1537 *
1538 * < 0 - Error occurred (error is passed to user process)
1539 *
1540 * 0   - OK - proceed with automatic read or write.
1541 *
1542 * > 0 - OK - read or write has been done by the strategy routine, so
1543 *       return immediately.
1544 *
1545 * There must be a proc_handler routine for any terminal nodes
1546 * mirrored under /proc/sys (non-terminals are handled by a built-in
1547 * directory handler).  Several default handlers are available to
1548 * cover common cases -
1549 *
1550 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1551 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 
1552 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1553 *
1554 * It is the handler's job to read the input buffer from user memory
1555 * and process it. The handler should return 0 on success.
1556 *
1557 * This routine returns %NULL on a failure to register, and a pointer
1558 * to the table header on success.
1559 */
1560struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1561{
1562        struct ctl_table_header *tmp;
1563        tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1564        if (!tmp)
1565                return NULL;
1566        tmp->ctl_table = table;
1567        INIT_LIST_HEAD(&tmp->ctl_entry);
1568        tmp->used = 0;
1569        tmp->unregistering = NULL;
1570        sysctl_set_parent(NULL, table);
1571        if (sysctl_check_table(tmp->ctl_table)) {
1572                kfree(tmp);
1573                return NULL;
1574        }
1575        spin_lock(&sysctl_lock);
1576        list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1577        spin_unlock(&sysctl_lock);
1578        return tmp;
1579}
1580
1581/**
1582 * unregister_sysctl_table - unregister a sysctl table hierarchy
1583 * @header: the header returned from register_sysctl_table
1584 *
1585 * Unregisters the sysctl table and all children. proc entries may not
1586 * actually be removed until they are no longer used by anyone.
1587 */
1588void unregister_sysctl_table(struct ctl_table_header * header)
1589{
1590        might_sleep();
1591
1592        if (header == NULL)
1593                return;
1594
1595        spin_lock(&sysctl_lock);
1596        start_unregistering(header);
1597        spin_unlock(&sysctl_lock);
1598        kfree(header);
1599}
1600
1601#else /* !CONFIG_SYSCTL */
1602struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1603{
1604        return NULL;
1605}
1606
1607void unregister_sysctl_table(struct ctl_table_header * table)
1608{
1609}
1610
1611#endif /* CONFIG_SYSCTL */
1612
1613/*
1614 * /proc/sys support
1615 */
1616
1617#ifdef CONFIG_PROC_SYSCTL
1618
1619static int _proc_do_string(void* data, int maxlen, int write,
1620                           struct file *filp, void __user *buffer,
1621                           size_t *lenp, loff_t *ppos)
1622{
1623        size_t len;
1624        char __user *p;
1625        char c;
1626
1627        if (!data || !maxlen || !*lenp) {
1628                *lenp = 0;
1629                return 0;
1630        }
1631
1632        if (write) {
1633                len = 0;
1634                p = buffer;
1635                while (len < *lenp) {
1636                        if (get_user(c, p++))
1637                                return -EFAULT;
1638                        if (c == 0 || c == '\n')
1639                                break;
1640                        len++;
1641                }
1642                if (len >= maxlen)
1643                        len = maxlen-1;
1644                if(copy_from_user(data, buffer, len))
1645                        return -EFAULT;
1646                ((char *) data)[len] = 0;
1647                *ppos += *lenp;
1648        } else {
1649                len = strlen(data);
1650                if (len > maxlen)
1651                        len = maxlen;
1652
1653                if (*ppos > len) {
1654                        *lenp = 0;
1655                        return 0;
1656                }
1657
1658                data += *ppos;
1659                len  -= *ppos;
1660
1661                if (len > *lenp)
1662                        len = *lenp;
1663                if (len)
1664                        if(copy_to_user(buffer, data, len))
1665                                return -EFAULT;
1666                if (len < *lenp) {
1667                        if(put_user('\n', ((char __user *) buffer) + len))
1668                                return -EFAULT;
1669                        len++;
1670                }
1671                *lenp = len;
1672                *ppos += len;
1673        }
1674        return 0;
1675}
1676
1677/**
1678 * proc_dostring - read a string sysctl
1679 * @table: the sysctl table
1680 * @write: %TRUE if this is a write to the sysctl file
1681 * @filp: the file structure
1682 * @buffer: the user buffer
1683 * @lenp: the size of the user buffer
1684 * @ppos: file position
1685 *
1686 * Reads/writes a string from/to the user buffer. If the kernel
1687 * buffer provided is not large enough to hold the string, the
1688 * string is truncated. The copied string is %NULL-terminated.
1689 * If the string is being read by the user process, it is copied
1690 * and a newline '\n' is added. It is truncated if the buffer is
1691 * not large enough.
1692 *
1693 * Returns 0 on success.
1694 */
1695int proc_dostring(struct ctl_table *table, int write, struct file *filp,
1696                  void __user *buffer, size_t *lenp, loff_t *ppos)
1697{
1698        return _proc_do_string(table->data, table->maxlen, write, filp,
1699                               buffer, lenp, ppos);
1700}
1701
1702
1703static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1704                                 int *valp,
1705                                 int write, void *data)
1706{
1707        if (write) {
1708                *valp = *negp ? -*lvalp : *lvalp;
1709        } else {
1710                int val = *valp;
1711                if (val < 0) {
1712                        *negp = -1;
1713                        *lvalp = (unsigned long)-val;
1714                } else {
1715                        *negp = 0;
1716                        *lvalp = (unsigned long)val;
1717                }
1718        }
1719        return 0;
1720}
1721
1722static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
1723                  int write, struct file *filp, void __user *buffer,
1724                  size_t *lenp, loff_t *ppos,
1725                  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1726                              int write, void *data),
1727                  void *data)
1728{
1729#define TMPBUFLEN 21
1730        int *i, vleft, first=1, neg, val;
1731        unsigned long lval;
1732        size_t left, len;
1733        
1734        char buf[TMPBUFLEN], *p;
1735        char __user *s = buffer;
1736        
1737        if (!tbl_data || !table->maxlen || !*lenp ||
1738            (*ppos && !write)) {
1739                *lenp = 0;
1740                return 0;
1741        }
1742        
1743        i = (int *) tbl_data;
1744        vleft = table->maxlen / sizeof(*i);
1745        left = *lenp;
1746
1747        if (!conv)
1748                conv = do_proc_dointvec_conv;
1749
1750        for (; left && vleft--; i++, first=0) {
1751                if (write) {
1752                        while (left) {
1753                                char c;
1754                                if (get_user(c, s))
1755                                        return -EFAULT;
1756                                if (!isspace(c))
1757                                        break;
1758                                left--;
1759                                s++;
1760                        }
1761                        if (!left)
1762                                break;
1763                        neg = 0;
1764                        len = left;
1765                        if (len > sizeof(buf) - 1)
1766                                len = sizeof(buf) - 1;
1767                        if (copy_from_user(buf, s, len))
1768                                return -EFAULT;
1769                        buf[len] = 0;
1770                        p = buf;
1771                        if (*p == '-' && left > 1) {
1772                                neg = 1;
1773                                p++;
1774                        }
1775                        if (*p < '0' || *p > '9')
1776                                break;
1777
1778                        lval = simple_strtoul(p, &p, 0);
1779
1780                        len = p-buf;
1781                        if ((len < left) && *p && !isspace(*p))
1782                                break;
1783                        if (neg)
1784                                val = -val;
1785                        s += len;
1786                        left -= len;
1787
1788                        if (conv(&neg, &lval, i, 1, data))
1789                                break;
1790                } else {
1791                        p = buf;
1792                        if (!first)
1793                                *p++ = '\t';
1794        
1795                        if (conv(&neg, &lval, i, 0, data))
1796                                break;
1797
1798                        sprintf(p, "%s%lu", neg ? "-" : "", lval);
1799                        len = strlen(buf);
1800                        if (len > left)
1801                                len = left;
1802                        if(copy_to_user(s, buf, len))
1803                                return -EFAULT;
1804                        left -= len;
1805                        s += len;
1806                }
1807        }
1808
1809        if (!write && !first && left) {
1810                if(put_user('\n', s))
1811                        return -EFAULT;
1812                left--, s++;
1813        }
1814        if (write) {
1815                while (left) {
1816                        char c;
1817                        if (get_user(c, s++))
1818                                return -EFAULT;
1819                        if (!isspace(c))
1820                                break;
1821                        left--;
1822                }
1823        }
1824        if (write && first)
1825                return -EINVAL;
1826        *lenp -= left;
1827        *ppos += *lenp;
1828        return 0;
1829#undef TMPBUFLEN
1830}
1831
1832static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
1833                  void __user *buffer, size_t *lenp, loff_t *ppos,
1834                  int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1835                              int write, void *data),
1836                  void *data)
1837{
1838        return __do_proc_dointvec(table->data, table, write, filp,
1839                        buffer, lenp, ppos, conv, data);
1840}
1841
1842/**
1843 * proc_dointvec - read a vector of integers
1844 * @table: the sysctl table
1845 * @write: %TRUE if this is a write to the sysctl file
1846 * @filp: the file structure
1847 * @buffer: the user buffer
1848 * @lenp: the size of the user buffer
1849 * @ppos: file position
1850 *
1851 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1852 * values from/to the user buffer, treated as an ASCII string. 
1853 *
1854 * Returns 0 on success.
1855 */
1856int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
1857                     void __user *buffer, size_t *lenp, loff_t *ppos)
1858{
1859    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1860                            NULL,NULL);
1861}
1862
1863#define OP_SET  0
1864#define OP_AND  1
1865#define OP_OR   2
1866
1867static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1868                                      int *valp,
1869                                      int write, void *data)
1870{
1871        int op = *(int *)data;
1872        if (write) {
1873                int val = *negp ? -*lvalp : *lvalp;
1874                switch(op) {
1875                case OP_SET:    *valp = val; break;
1876                case OP_AND:    *valp &= val; break;
1877                case OP_OR:     *valp |= val; break;
1878                }
1879        } else {
1880                int val = *valp;
1881                if (val < 0) {
1882                        *negp = -1;
1883                        *lvalp = (unsigned long)-val;
1884                } else {
1885                        *negp = 0;
1886                        *lvalp = (unsigned long)val;
1887                }
1888        }
1889        return 0;
1890}
1891
1892#ifdef CONFIG_SECURITY_CAPABILITIES
1893/*
1894 *      init may raise the set.
1895 */
1896
1897int proc_dointvec_bset(struct ctl_table *table, int write, struct file *filp,
1898                        void __user *buffer, size_t *lenp, loff_t *ppos)
1899{
1900        int op;
1901
1902        if (write && !capable(CAP_SYS_MODULE)) {
1903                return -EPERM;
1904        }
1905
1906        op = is_global_init(current) ? OP_SET : OP_AND;
1907        return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1908                                do_proc_dointvec_bset_conv,&op);
1909}
1910#endif /* def CONFIG_SECURITY_CAPABILITIES */
1911
1912/*
1913 *      Taint values can only be increased
1914 */
1915static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
1916                               void __user *buffer, size_t *lenp, loff_t *ppos)
1917{
1918        int op;
1919
1920        if (write && !capable(CAP_SYS_ADMIN))
1921                return -EPERM;
1922
1923        op = OP_OR;
1924        return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1925                                do_proc_dointvec_bset_conv,&op);
1926}
1927
1928struct do_proc_dointvec_minmax_conv_param {
1929        int *min;
1930        int *max;
1931};
1932
1933static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 
1934                                        int *valp, 
1935                                        int write, void *data)
1936{
1937        struct do_proc_dointvec_minmax_conv_param *param = data;
1938        if (write) {
1939                int val = *negp ? -*lvalp : *lvalp;
1940                if ((param->min && *param->min > val) ||
1941                    (param->max && *param->max < val))
1942                        return -EINVAL;
1943                *valp = val;
1944        } else {
1945                int val = *valp;
1946                if (val < 0) {
1947                        *negp = -1;
1948                        *lvalp = (unsigned long)-val;
1949                } else {
1950                        *negp = 0;
1951                        *lvalp = (unsigned long)val;
1952                }
1953        }
1954        return 0;
1955}
1956
1957/**
1958 * proc_dointvec_minmax - read a vector of integers with min/max values
1959 * @table: the sysctl table
1960 * @write: %TRUE if this is a write to the sysctl file
1961 * @filp: the file structure
1962 * @buffer: the user buffer
1963 * @lenp: the size of the user buffer
1964 * @ppos: file position
1965 *
1966 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1967 * values from/to the user buffer, treated as an ASCII string.
1968 *
1969 * This routine will ensure the values are within the range specified by
1970 * table->extra1 (min) and table->extra2 (max).
1971 *
1972 * Returns 0 on success.
1973 */
1974int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
1975                  void __user *buffer, size_t *lenp, loff_t *ppos)
1976{
1977        struct do_proc_dointvec_minmax_conv_param param = {
1978                .min = (int *) table->extra1,
1979                .max = (int *) table->extra2,
1980        };
1981        return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1982                                do_proc_dointvec_minmax_conv, &param);
1983}
1984
1985static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
1986                                     struct file *filp,
1987                                     void __user *buffer,
1988                                     size_t *lenp, loff_t *ppos,
1989                                     unsigned long convmul,
1990                                     unsigned long convdiv)
1991{
1992#define TMPBUFLEN 21
1993        unsigned long *i, *min, *max, val;
1994        int vleft, first=1, neg;
1995        size_t len, left;
1996        char buf[TMPBUFLEN], *p;
1997        char __user *s = buffer;
1998        
1999        if (!data || !table->maxlen || !*lenp ||
2000            (*ppos && !write)) {
2001                *lenp = 0;
2002                return 0;
2003        }
2004        
2005        i = (unsigned long *) data;
2006        min = (unsigned long *) table->extra1;
2007        max = (unsigned long *) table->extra2;
2008        vleft = table->maxlen / sizeof(unsigned long);
2009        left = *lenp;
2010        
2011        for (; left && vleft--; i++, min++, max++, first=0) {
2012                if (write) {
2013                        while (left) {
2014                                char c;
2015                                if (get_user(c, s))
2016                                        return -EFAULT;
2017                                if (!isspace(c))
2018                                        break;
2019                                left--;
2020                                s++;
2021                        }
2022                        if (!left)
2023                                break;
2024                        neg = 0;
2025                        len = left;
2026                        if (len > TMPBUFLEN-1)
2027                                len = TMPBUFLEN-1;
2028                        if (copy_from_user(buf, s, len))
2029                                return -EFAULT;
2030                        buf[len] = 0;
2031                        p = buf;
2032                        if (*p == '-' && left > 1) {
2033                                neg = 1;
2034                                p++;
2035                        }
2036                        if (*p < '0' || *p > '9')
2037                                break;
2038                        val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2039                        len = p-buf;
2040                        if ((len < left) && *p && !isspace(*p))
2041                                break;
2042                        if (neg)
2043                                val = -val;
2044                        s += len;
2045                        left -= len;
2046
2047                        if(neg)
2048                                continue;
2049                        if ((min && val < *min) || (max && val > *max))
2050                                continue;
2051                        *i = val;
2052                } else {
2053                        p = buf;
2054                        if (!first)
2055                                *p++ = '\t';
2056                        sprintf(p, "%lu", convdiv * (*i) / convmul);
2057                        len = strlen(buf);
2058                        if (len > left)
2059                                len = left;
2060                        if(copy_to_user(s, buf, len))
2061                                return -EFAULT;
2062                        left -= len;
2063                        s += len;
2064                }
2065        }
2066
2067        if (!write && !first && left) {
2068                if(put_user('\n', s))
2069                        return -EFAULT;
2070                left--, s++;
2071        }
2072        if (write) {
2073                while (left) {
2074                        char c;
2075                        if (get_user(c, s++))
2076                                return -EFAULT;
2077                        if (!isspace(c))
2078                                break;
2079                        left--;
2080                }
2081        }
2082        if (write && first)
2083                return -EINVAL;
2084        *lenp -= left;
2085        *ppos += *lenp;
2086        return 0;
2087#undef TMPBUFLEN
2088}
2089
2090static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2091                                     struct file *filp,
2092                                     void __user *buffer,
2093                                     size_t *lenp, loff_t *ppos,
2094                                     unsigned long convmul,
2095                                     unsigned long convdiv)
2096{
2097        return __do_proc_doulongvec_minmax(table->data, table, write,
2098                        filp, buffer, lenp, ppos, convmul, convdiv);
2099}
2100
2101/**
2102 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2103 * @table: the sysctl table
2104 * @write: %TRUE if this is a write to the sysctl file
2105 * @filp: the file structure
2106 * @buffer: the user buffer
2107 * @lenp: the size of the user buffer
2108 * @ppos: file position
2109 *
2110 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2111 * values from/to the user buffer, treated as an ASCII string.
2112 *
2113 * This routine will ensure the values are within the range specified by
2114 * table->extra1 (min) and table->extra2 (max).
2115 *
2116 * Returns 0 on success.
2117 */
2118int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2119                           void __user *buffer, size_t *lenp, loff_t *ppos)
2120{
2121    return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2122}
2123
2124/**
2125 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2126 * @table: the sysctl table
2127 * @write: %TRUE if this is a write to the sysctl file
2128 * @filp: the file structure
2129 * @buffer: the user buffer
2130 * @lenp: the size of the user buffer
2131 * @ppos: file position
2132 *
2133 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2134 * values from/to the user buffer, treated as an ASCII string. The values
2135 * are treated as milliseconds, and converted to jiffies when they are stored.
2136 *
2137 * This routine will ensure the values are within the range specified by
2138 * table->extra1 (min) and table->extra2 (max).
2139 *
2140 * Returns 0 on success.
2141 */
2142int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2143                                      struct file *filp,
2144                                      void __user *buffer,
2145                                      size_t *lenp, loff_t *ppos)
2146{
2147    return do_proc_doulongvec_minmax(table, write, filp, buffer,
2148                                     lenp, ppos, HZ, 1000l);
2149}
2150
2151
2152static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2153                                         int *valp,
2154                                         int write, void *data)
2155{
2156        if (write) {
2157                if (*lvalp > LONG_MAX / HZ)
2158                        return 1;
2159                *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2160        } else {
2161                int val = *valp;
2162                unsigned long lval;
2163                if (val < 0) {
2164                        *negp = -1;
2165                        lval = (unsigned long)-val;
2166                } else {
2167                        *negp = 0;
2168                        lval = (unsigned long)val;
2169                }
2170                *lvalp = lval / HZ;
2171        }
2172        return 0;
2173}
2174
2175static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2176                                                int *valp,
2177                                                int write, void *data)
2178{
2179        if (write) {
2180                if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2181                        return 1;
2182                *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2183        } else {
2184                int val = *valp;
2185                unsigned long lval;
2186                if (val < 0) {
2187                        *negp = -1;
2188                        lval = (unsigned long)-val;
2189                } else {
2190                        *negp = 0;
2191                        lval = (unsigned long)val;
2192                }
2193                *lvalp = jiffies_to_clock_t(lval);
2194        }
2195        return 0;
2196}
2197
2198static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2199                                            int *valp,
2200                                            int write, void *data)
2201{
2202        if (write) {
2203                *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2204        } else {
2205                int val = *valp;
2206                unsigned long lval;
2207                if (val < 0) {
2208                        *negp = -1;
2209                        lval = (unsigned long)-val;
2210                } else {
2211                        *negp = 0;
2212                        lval = (unsigned long)val;
2213                }
2214                *lvalp = jiffies_to_msecs(lval);
2215        }
2216        return 0;
2217}
2218
2219/**
2220 * proc_dointvec_jiffies - read a vector of integers as seconds
2221 * @table: the sysctl table
2222 * @write: %TRUE if this is a write to the sysctl file
2223 * @filp: the file structure
2224 * @buffer: the user buffer
2225 * @lenp: the size of the user buffer
2226 * @ppos: file position
2227 *
2228 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2229 * values from/to the user buffer, treated as an ASCII string. 
2230 * The values read are assumed to be in seconds, and are converted into
2231 * jiffies.
2232 *
2233 * Returns 0 on success.
2234 */
2235int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2236                          void __user *buffer, size_t *lenp, loff_t *ppos)
2237{
2238    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2239                            do_proc_dointvec_jiffies_conv,NULL);
2240}
2241
2242/**
2243 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2244 * @table: the sysctl table
2245 * @write: %TRUE if this is a write to the sysctl file
2246 * @filp: the file structure
2247 * @buffer: the user buffer
2248 * @lenp: the size of the user buffer
2249 * @ppos: pointer to the file position
2250 *
2251 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2252 * values from/to the user buffer, treated as an ASCII string. 
2253 * The values read are assumed to be in 1/USER_HZ seconds, and 
2254 * are converted into jiffies.
2255 *
2256 * Returns 0 on success.
2257 */
2258int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2259                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2260{
2261    return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2262                            do_proc_dointvec_userhz_jiffies_conv,NULL);
2263}
2264
2265/**
2266 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2267 * @table: the sysctl table
2268 * @write: %TRUE if this is a write to the sysctl file
2269 * @filp: the file structure
2270 * @buffer: the user buffer
2271 * @lenp: the size of the user buffer
2272 * @ppos: file position
2273 * @ppos: the current position in the file
2274 *
2275 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2276 * values from/to the user buffer, treated as an ASCII string. 
2277 * The values read are assumed to be in 1/1000 seconds, and 
2278 * are converted into jiffies.
2279 *
2280 * Returns 0 on success.
2281 */
2282int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2283                             void __user *buffer, size_t *lenp, loff_t *ppos)
2284{
2285        return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2286                                do_proc_dointvec_ms_jiffies_conv, NULL);
2287}
2288
2289static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2290                           void __user *buffer, size_t *lenp, loff_t *ppos)
2291{
2292        struct pid *new_pid;
2293        pid_t tmp;
2294        int r;
2295
2296        tmp = pid_nr_ns(cad_pid, current->nsproxy->pid_ns);
2297
2298        r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2299                               lenp, ppos, NULL, NULL);
2300        if (r || !write)
2301                return r;
2302
2303        new_pid = find_get_pid(tmp);
2304        if (!new_pid)
2305                return -ESRCH;
2306
2307        put_pid(xchg(&cad_pid, new_pid));
2308        return 0;
2309}
2310
2311#else /* CONFIG_PROC_FS */
2312
2313int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2314                  void __user *buffer, size_t *lenp, loff_t *ppos)
2315{
2316        return -ENOSYS;
2317}
2318
2319int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2320                  void __user *buffer, size_t *lenp, loff_t *ppos)
2321{
2322        return -ENOSYS;
2323}
2324
2325int proc_dointvec_bset(struct ctl_table *table, int write, struct file *filp,
2326                        void __user *buffer, size_t *lenp, loff_t *ppos)
2327{
2328        return -ENOSYS;
2329}
2330
2331int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2332                    void __user *buffer, size_t *lenp, loff_t *ppos)
2333{
2334        return -ENOSYS;
2335}
2336
2337int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2338                    void __user *buffer, size_t *lenp, loff_t *ppos)
2339{
2340        return -ENOSYS;
2341}
2342
2343int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2344                    void __user *buffer, size_t *lenp, loff_t *ppos)
2345{
2346        return -ENOSYS;
2347}
2348
2349int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2350                             void __user *buffer, size_t *lenp, loff_t *ppos)
2351{
2352        return -ENOSYS;
2353}
2354
2355int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2356                    void __user *buffer, size_t *lenp, loff_t *ppos)
2357{
2358        return -ENOSYS;
2359}
2360
2361int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2362                                      struct file *filp,
2363                                      void __user *buffer,
2364                                      size_t *lenp, loff_t *ppos)
2365{
2366    return -ENOSYS;
2367}
2368
2369
2370#endif /* CONFIG_PROC_FS */
2371
2372
2373#ifdef CONFIG_SYSCTL_SYSCALL
2374/*
2375 * General sysctl support routines 
2376 */
2377
2378/* The generic sysctl data routine (used if no strategy routine supplied) */
2379int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2380                void __user *oldval, size_t __user *oldlenp,
2381                void __user *newval, size_t newlen)
2382{
2383        size_t len;
2384
2385        /* Get out of I don't have a variable */
2386        if (!table->data || !table->maxlen)
2387                return -ENOTDIR;
2388
2389        if (oldval && oldlenp) {
2390                if (get_user(len, oldlenp))
2391                        return -EFAULT;
2392                if (len) {
2393                        if (len > table->maxlen)
2394                                len = table->maxlen;
2395                        if (copy_to_user(oldval, table->data, len))
2396                                return -EFAULT;
2397                        if (put_user(len, oldlenp))
2398                                return -EFAULT;
2399                }
2400        }
2401
2402        if (newval && newlen) {
2403                if (newlen > table->maxlen)
2404                        newlen = table->maxlen;
2405
2406                if (copy_from_user(table->data, newval, newlen))
2407                        return -EFAULT;
2408        }
2409        return 1;
2410}
2411
2412/* The generic string strategy routine: */
2413int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2414                  void __user *oldval, size_t __user *oldlenp,
2415                  void __user *newval, size_t newlen)
2416{
2417        if (!table->data || !table->maxlen) 
2418                return -ENOTDIR;
2419        
2420        if (oldval && oldlenp) {
2421                size_t bufsize;
2422                if (get_user(bufsize, oldlenp))
2423                        return -EFAULT;
2424                if (bufsize) {
2425                        size_t len = strlen(table->data), copied;
2426
2427                        /* This shouldn't trigger for a well-formed sysctl */
2428                        if (len > table->maxlen)
2429                                len = table->maxlen;
2430
2431                        /* Copy up to a max of bufsize-1 bytes of the string */
2432                        copied = (len >= bufsize) ? bufsize - 1 : len;
2433
2434                        if (copy_to_user(oldval, table->data, copied) ||
2435                            put_user(0, (char __user *)(oldval + copied)))
2436                                return -EFAULT;
2437                        if (put_user(len, oldlenp))
2438                                return -EFAULT;
2439                }
2440        }
2441        if (newval && newlen) {
2442                size_t len = newlen;
2443                if (len > table->maxlen)
2444                        len = table->maxlen;
2445                if(copy_from_user(table->data, newval, len))
2446                        return -EFAULT;
2447                if (len == table->maxlen)
2448                        len--;
2449                ((char *) table->data)[len] = 0;
2450        }
2451        return 1;
2452}
2453
2454/*
2455 * This function makes sure that all of the integers in the vector
2456 * are between the minimum and maximum values given in the arrays
2457 * table->extra1 and table->extra2, respectively.
2458 */
2459int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2460                void __user *oldval, size_t __user *oldlenp,
2461                void __user *newval, size_t newlen)
2462{
2463
2464        if (newval && newlen) {
2465                int __user *vec = (int __user *) newval;
2466                int *min = (int *) table->extra1;
2467                int *max = (int *) table->extra2;
2468                size_t length;
2469                int i;
2470
2471                if (newlen % sizeof(int) != 0)
2472                        return -EINVAL;
2473
2474                if (!table->extra1 && !table->extra2)
2475                        return 0;
2476
2477                if (newlen > table->maxlen)
2478                        newlen = table->maxlen;
2479                length = newlen / sizeof(int);
2480
2481                for (i = 0; i < length; i++) {
2482                        int value;
2483                        if (get_user(value, vec + i))
2484                                return -EFAULT;
2485                        if (min && value < min[i])
2486                                return -EINVAL;
2487                        if (max && value > max[i])
2488                                return -EINVAL;
2489                }
2490        }
2491        return 0;
2492}
2493
2494/* Strategy function to convert jiffies to seconds */ 
2495int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2496                void __user *oldval, size_t __user *oldlenp,
2497                void __user *newval, size_t newlen)
2498{
2499        if (oldval && oldlenp) {
2500                size_t olen;
2501
2502                if (get_user(olen, oldlenp))
2503                        return -EFAULT;
2504                if (olen) {
2505                        int val;
2506
2507                        if (olen < sizeof(int))
2508                                return -EINVAL;
2509
2510                        val = *(int *)(table->data) / HZ;
2511                        if (put_user(val, (int __user *)oldval))
2512                                return -EFAULT;
2513                        if (put_user(sizeof(int), oldlenp))
2514                                return -EFAULT;
2515                }
2516        }
2517        if (newval && newlen) { 
2518                int new;
2519                if (newlen != sizeof(int))
2520                        return -EINVAL; 
2521                if (get_user(new, (int __user *)newval))
2522                        return -EFAULT;
2523                *(int *)(table->data) = new*HZ; 
2524        }
2525        return 1;
2526}
2527
2528/* Strategy function to convert jiffies to seconds */ 
2529int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2530                void __user *oldval, size_t __user *oldlenp,
2531                void __user *newval, size_t newlen)
2532{
2533        if (oldval && oldlenp) {
2534                size_t olen;
2535
2536                if (get_user(olen, oldlenp))
2537                        return -EFAULT;
2538                if (olen) {
2539                        int val;
2540
2541                        if (olen < sizeof(int))
2542                                return -EINVAL;
2543
2544                        val = jiffies_to_msecs(*(int *)(table->data));
2545                        if (put_user(val, (int __user *)oldval))
2546                                return -EFAULT;
2547                        if (put_user(sizeof(int), oldlenp))
2548                                return -EFAULT;
2549                }
2550        }
2551        if (newval && newlen) { 
2552                int new;
2553                if (newlen != sizeof(int))
2554                        return -EINVAL; 
2555                if (get_user(new, (int __user *)newval))
2556                        return -EFAULT;
2557                *(int *)(table->data) = msecs_to_jiffies(new);
2558        }
2559        return 1;
2560}
2561
2562
2563
2564#else /* CONFIG_SYSCTL_SYSCALL */
2565
2566
2567asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2568{
2569        struct __sysctl_args tmp;
2570        int error;
2571
2572        if (copy_from_user(&tmp, args, sizeof(tmp)))
2573                return -EFAULT;
2574
2575        error = deprecated_sysctl_warning(&tmp);
2576
2577        /* If no error reading the parameters then just -ENOSYS ... */
2578        if (!error)
2579                error = -ENOSYS;
2580
2581        return error;
2582}
2583
2584int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2585                  void __user *oldval, size_t __user *oldlenp,
2586                  void __user *newval, size_t newlen)
2587{
2588        return -ENOSYS;
2589}
2590
2591int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2592                  void __user *oldval, size_t __user *oldlenp,
2593                  void __user *newval, size_t newlen)
2594{
2595        return -ENOSYS;
2596}
2597
2598int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2599                void __user *oldval, size_t __user *oldlenp,
2600                void __user *newval, size_t newlen)
2601{
2602        return -ENOSYS;
2603}
2604
2605int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2606                void __user *oldval, size_t __user *oldlenp,
2607                void __user *newval, size_t newlen)
2608{
2609        return -ENOSYS;
2610}
2611
2612int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2613                void __user *oldval, size_t __user *oldlenp,
2614                void __user *newval, size_t newlen)
2615{
2616        return -ENOSYS;
2617}
2618
2619#endif /* CONFIG_SYSCTL_SYSCALL */
2620
2621static int deprecated_sysctl_warning(struct __sysctl_args *args)
2622{
2623        static int msg_count;
2624        int name[CTL_MAXNAME];
2625        int i;
2626
2627        /* Check args->nlen. */
2628        if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
2629                return -ENOTDIR;
2630
2631        /* Read in the sysctl name for better debug message logging */
2632        for (i = 0; i < args->nlen; i++)
2633                if (get_user(name[i], args->name + i))
2634                        return -EFAULT;
2635
2636        /* Ignore accesses to kernel.version */
2637        if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2638                return 0;
2639
2640        if (msg_count < 5) {
2641                msg_count++;
2642                printk(KERN_INFO
2643                        "warning: process `%s' used the deprecated sysctl "
2644                        "system call with ", current->comm);
2645                for (i = 0; i < args->nlen; i++)
2646                        printk("%d.", name[i]);
2647                printk("\n");
2648        }
2649        return 0;
2650}
2651
2652/*
2653 * No sense putting this after each symbol definition, twice,
2654 * exception granted :-)
2655 */
2656EXPORT_SYMBOL(proc_dointvec);
2657EXPORT_SYMBOL(proc_dointvec_jiffies);
2658EXPORT_SYMBOL(proc_dointvec_minmax);
2659EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2660EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2661EXPORT_SYMBOL(proc_dostring);
2662EXPORT_SYMBOL(proc_doulongvec_minmax);
2663EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2664EXPORT_SYMBOL(register_sysctl_table);
2665EXPORT_SYMBOL(sysctl_intvec);
2666EXPORT_SYMBOL(sysctl_jiffies);
2667EXPORT_SYMBOL(sysctl_ms_jiffies);
2668EXPORT_SYMBOL(sysctl_string);
2669EXPORT_SYMBOL(sysctl_data);
2670EXPORT_SYMBOL(unregister_sysctl_table);
2671