kernel/sysctl.c

   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/signal.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/security.h>
  29 #include <linux/ctype.h>
  30 #include <linux/kmemcheck.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/ratelimit.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_event.h>
  54 #include <linux/kprobes.h>
  55
  56 #include <asm/uaccess.h>
  57 #include <asm/processor.h>
  58
  59 #ifdef CONFIG_X86
  60 #include <asm/nmi.h>
  61 #include <asm/stacktrace.h>
  62 #include <asm/io.h>
  63 #endif
  64 #ifdef CONFIG_BSD_PROCESS_ACCT
  65 #include <linux/acct.h>
  66 #endif
  67 #ifdef CONFIG_RT_MUTEXES
  68 #include <linux/rtmutex.h>
  69 #endif
  70 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  71 #include <linux/lockdep.h>
  72 #endif
  73 #ifdef CONFIG_CHR_DEV_SG
  74 #include <scsi/sg.h>
  75 #endif
  76
  77
  78 #if defined(CONFIG_SYSCTL)
  79
  80 /* External variables not in a header file. */
  81 extern int sysctl_overcommit_memory;
  82 extern int sysctl_overcommit_ratio;
  83 extern int sysctl_panic_on_oom;
  84 extern int sysctl_oom_kill_allocating_task;
  85 extern int sysctl_oom_dump_tasks;
  86 extern int max_threads;
  87 extern int core_uses_pid;
  88 extern int suid_dumpable;
  89 extern char core_pattern[];
  90 extern unsigned int core_pipe_limit;
  91 extern int pid_max;
  92 extern int min_free_kbytes;
  93 extern int pid_max_min, pid_max_max;
  94 extern int sysctl_drop_caches;
  95 extern int percpu_pagelist_fraction;
  96 extern int compat_log;
  97 extern int latencytop_enabled;
  98 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  99 #ifndef CONFIG_MMU
 100 extern int sysctl_nr_trim_pages;
 101 #endif
 102 #ifdef CONFIG_BLOCK
 103 extern int blk_iopoll_enabled;
 104 #endif
 105
 106 /* Constants used for minimum and  maximum */
 107 #ifdef CONFIG_DETECT_SOFTLOCKUP
 108 static int sixty = 60;
 109 static int neg_one = -1;
 110 #endif
 111
 112 static int zero;
 113 static int __maybe_unused one = 1;
 114 static int __maybe_unused two = 2;
 115 static unsigned long one_ul = 1;
 116 static int one_hundred = 100;
 117 #ifdef CONFIG_PRINTK
 118 static int ten_thousand = 10000;
 119 #endif
 120
 121 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 122 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 123
 124 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 125 static int maxolduid = 65535;
 126 static int minolduid;
 127 static int min_percpu_pagelist_fract = 8;
 128
 129 static int ngroups_max = NGROUPS_MAX;
 130
 131 #ifdef CONFIG_SPARC
 132 #include <asm/system.h>
 133 #endif
 134
 135 #ifdef CONFIG_SPARC64
 136 extern int sysctl_tsb_ratio;
 137 #endif
 138
 139 #ifdef __hppa__
 140 extern int pwrsw_enabled;
 141 extern int unaligned_enabled;
 142 #endif
 143
 144 #ifdef CONFIG_S390
 145 #ifdef CONFIG_MATHEMU
 146 extern int sysctl_ieee_emulation_warnings;
 147 #endif
 148 extern int sysctl_userprocess_debug;
 149 extern int spin_retry;
 150 #endif
 151
 152 #ifdef CONFIG_IA64
 153 extern int no_unaligned_warning;
 154 extern int unaligned_dump_stack;
 155 #endif
 156
 157 extern struct ratelimit_state printk_ratelimit_state;
 158
 159 #ifdef CONFIG_PROC_SYSCTL
 160 static int proc_do_cad_pid(struct ctl_table *table, int write,
 161                   void __user *buffer, size_t *lenp, loff_t *ppos);
 162 static int proc_taint(struct ctl_table *table, int write,
 163                                void __user *buffer, size_t *lenp, loff_t *ppos);
 164 #endif
 165
 166 #ifdef CONFIG_MAGIC_SYSRQ
 167 static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
 168
 169 static int sysrq_sysctl_handler(ctl_table *table, int write,
 170                                 void __user *buffer, size_t *lenp,
 171                                 loff_t *ppos)
 172 {
 173         int error;
 174
 175         error = proc_dointvec(table, write, buffer, lenp, ppos);
 176         if (error)
 177                 return error;
 178
 179         if (write)
 180                 sysrq_toggle_support(__sysrq_enabled);
 181
 182         return 0;
 183 }
 184
 185 #endif
 186
 187 static struct ctl_table root_table[];
 188 static struct ctl_table_root sysctl_table_root;
 189 static struct ctl_table_header root_table_header = {
 190         .count = 1,
 191         .ctl_table = root_table,
 192         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 193         .root = &sysctl_table_root,
 194         .set = &sysctl_table_root.default_set,
 195 };
 196 static struct ctl_table_root sysctl_table_root = {
 197         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 198         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 199 };
 200
 201 static struct ctl_table kern_table[];
 202 static struct ctl_table vm_table[];
 203 static struct ctl_table fs_table[];
 204 static struct ctl_table debug_table[];
 205 static struct ctl_table dev_table[];
 206 extern struct ctl_table random_table[];
 207 #ifdef CONFIG_INOTIFY_USER
 208 extern struct ctl_table inotify_table[];
 209 #endif
 210 #ifdef CONFIG_EPOLL
 211 extern struct ctl_table epoll_table[];
 212 #endif
 213
 214 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 215 int sysctl_legacy_va_layout;
 216 #endif
 217
 218 /* The default sysctl tables: */
 219
 220 static struct ctl_table root_table[] = {
 221         {
 222                 .procname       = "kernel",
 223                 .mode           = 0555,
 224                 .child          = kern_table,
 225         },
 226         {
 227                 .procname       = "vm",
 228                 .mode           = 0555,
 229                 .child          = vm_table,
 230         },
 231         {
 232                 .procname       = "fs",
 233                 .mode           = 0555,
 234                 .child          = fs_table,
 235         },
 236         {
 237                 .procname       = "debug",
 238                 .mode           = 0555,
 239                 .child          = debug_table,
 240         },
 241         {
 242                 .procname       = "dev",
 243                 .mode           = 0555,
 244                 .child          = dev_table,
 245         },
 246 /*
 247  * NOTE: do not add new entries to this table unless you have read
 248  * Documentation/sysctl/ctl_unnumbered.txt
 249  */
 250         { }
 251 };
 252
 253 #ifdef CONFIG_SCHED_DEBUG
 254 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 255 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 256 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 257 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 258 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 259 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 260 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
 261 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
 262 #endif
 263
 264 static struct ctl_table kern_table[] = {
 265         {
 266                 .procname       = "sched_child_runs_first",
 267                 .data           = &sysctl_sched_child_runs_first,
 268                 .maxlen         = sizeof(unsigned int),
 269                 .mode           = 0644,
 270                 .proc_handler   = proc_dointvec,
 271         },
 272 #ifdef CONFIG_SCHED_DEBUG
 273         {
 274                 .procname       = "sched_min_granularity_ns",
 275                 .data           = &sysctl_sched_min_granularity,
 276                 .maxlen         = sizeof(unsigned int),
 277                 .mode           = 0644,
 278                 .proc_handler   = sched_proc_update_handler,
 279                 .extra1         = &min_sched_granularity_ns,
 280                 .extra2         = &max_sched_granularity_ns,
 281         },
 282         {
 283                 .procname       = "sched_latency_ns",
 284                 .data           = &sysctl_sched_latency,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = sched_proc_update_handler,
 288                 .extra1         = &min_sched_granularity_ns,
 289                 .extra2         = &max_sched_granularity_ns,
 290         },
 291         {
 292                 .procname       = "sched_wakeup_granularity_ns",
 293                 .data           = &sysctl_sched_wakeup_granularity,
 294                 .maxlen         = sizeof(unsigned int),
 295                 .mode           = 0644,
 296                 .proc_handler   = sched_proc_update_handler,
 297                 .extra1         = &min_wakeup_granularity_ns,
 298                 .extra2         = &max_wakeup_granularity_ns,
 299         },
 300         {
 301                 .procname       = "sched_shares_ratelimit",
 302                 .data           = &sysctl_sched_shares_ratelimit,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = sched_proc_update_handler,
 306                 .extra1         = &min_sched_shares_ratelimit,
 307                 .extra2         = &max_sched_shares_ratelimit,
 308         },
 309         {
 310                 .procname       = "sched_tunable_scaling",
 311                 .data           = &sysctl_sched_tunable_scaling,
 312                 .maxlen         = sizeof(enum sched_tunable_scaling),
 313                 .mode           = 0644,
 314                 .proc_handler   = sched_proc_update_handler,
 315                 .extra1         = &min_sched_tunable_scaling,
 316                 .extra2         = &max_sched_tunable_scaling,
 317         },
 318         {
 319                 .procname       = "sched_shares_thresh",
 320                 .data           = &sysctl_sched_shares_thresh,
 321                 .maxlen         = sizeof(unsigned int),
 322                 .mode           = 0644,
 323                 .proc_handler   = proc_dointvec_minmax,
 324                 .extra1         = &zero,
 325         },
 326         {
 327                 .procname       = "sched_migration_cost",
 328                 .data           = &sysctl_sched_migration_cost,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = proc_dointvec,
 332         },
 333         {
 334                 .procname       = "sched_nr_migrate",
 335                 .data           = &sysctl_sched_nr_migrate,
 336                 .maxlen         = sizeof(unsigned int),
 337                 .mode           = 0644,
 338                 .proc_handler   = proc_dointvec,
 339         },
 340         {
 341                 .procname       = "sched_time_avg",
 342                 .data           = &sysctl_sched_time_avg,
 343                 .maxlen         = sizeof(unsigned int),
 344                 .mode           = 0644,
 345                 .proc_handler   = proc_dointvec,
 346         },
 347         {
 348                 .procname       = "timer_migration",
 349                 .data           = &sysctl_timer_migration,
 350                 .maxlen         = sizeof(unsigned int),
 351                 .mode           = 0644,
 352                 .proc_handler   = proc_dointvec_minmax,
 353                 .extra1         = &zero,
 354                 .extra2         = &one,
 355         },
 356 #endif
 357         {
 358                 .procname       = "sched_rt_period_us",
 359                 .data           = &sysctl_sched_rt_period,
 360                 .maxlen         = sizeof(unsigned int),
 361                 .mode           = 0644,
 362                 .proc_handler   = sched_rt_handler,
 363         },
 364         {
 365                 .procname       = "sched_rt_runtime_us",
 366                 .data           = &sysctl_sched_rt_runtime,
 367                 .maxlen         = sizeof(int),
 368                 .mode           = 0644,
 369                 .proc_handler   = sched_rt_handler,
 370         },
 371         {
 372                 .procname       = "sched_compat_yield",
 373                 .data           = &sysctl_sched_compat_yield,
 374                 .maxlen         = sizeof(unsigned int),
 375                 .mode           = 0644,
 376                 .proc_handler   = proc_dointvec,
 377         },
 378 #ifdef CONFIG_PROVE_LOCKING
 379         {
 380                 .procname       = "prove_locking",
 381                 .data           = &prove_locking,
 382                 .maxlen         = sizeof(int),
 383                 .mode           = 0644,
 384                 .proc_handler   = proc_dointvec,
 385         },
 386 #endif
 387 #ifdef CONFIG_LOCK_STAT
 388         {
 389                 .procname       = "lock_stat",
 390                 .data           = &lock_stat,
 391                 .maxlen         = sizeof(int),
 392                 .mode           = 0644,
 393                 .proc_handler   = proc_dointvec,
 394         },
 395 #endif
 396         {
 397                 .procname       = "panic",
 398                 .data           = &panic_timeout,
 399                 .maxlen         = sizeof(int),
 400                 .mode           = 0644,
 401                 .proc_handler   = proc_dointvec,
 402         },
 403         {
 404                 .procname       = "core_uses_pid",
 405                 .data           = &core_uses_pid,
 406                 .maxlen         = sizeof(int),
 407                 .mode           = 0644,
 408                 .proc_handler   = proc_dointvec,
 409         },
 410         {
 411                 .procname       = "core_pattern",
 412                 .data           = core_pattern,
 413                 .maxlen         = CORENAME_MAX_SIZE,
 414                 .mode           = 0644,
 415                 .proc_handler   = proc_dostring,
 416         },
 417         {
 418                 .procname       = "core_pipe_limit",
 419                 .data           = &core_pipe_limit,
 420                 .maxlen         = sizeof(unsigned int),
 421                 .mode           = 0644,
 422                 .proc_handler   = proc_dointvec,
 423         },
 424 #ifdef CONFIG_PROC_SYSCTL
 425         {
 426                 .procname       = "tainted",
 427                 .maxlen         = sizeof(long),
 428                 .mode           = 0644,
 429                 .proc_handler   = proc_taint,
 430         },
 431 #endif
 432 #ifdef CONFIG_LATENCYTOP
 433         {
 434                 .procname       = "latencytop",
 435                 .data           = &latencytop_enabled,
 436                 .maxlen         = sizeof(int),
 437                 .mode           = 0644,
 438                 .proc_handler   = proc_dointvec,
 439         },
 440 #endif
 441 #ifdef CONFIG_BLK_DEV_INITRD
 442         {
 443                 .procname       = "real-root-dev",
 444                 .data           = &real_root_dev,
 445                 .maxlen         = sizeof(int),
 446                 .mode           = 0644,
 447                 .proc_handler   = proc_dointvec,
 448         },
 449 #endif
 450         {
 451                 .procname       = "print-fatal-signals",
 452                 .data           = &print_fatal_signals,
 453                 .maxlen         = sizeof(int),
 454                 .mode           = 0644,
 455                 .proc_handler   = proc_dointvec,
 456         },
 457 #ifdef CONFIG_SPARC
 458         {
 459                 .procname       = "reboot-cmd",
 460                 .data           = reboot_command,
 461                 .maxlen         = 256,
 462                 .mode           = 0644,
 463                 .proc_handler   = proc_dostring,
 464         },
 465         {
 466                 .procname       = "stop-a",
 467                 .data           = &stop_a_enabled,
 468                 .maxlen         = sizeof (int),
 469                 .mode           = 0644,
 470                 .proc_handler   = proc_dointvec,
 471         },
 472         {
 473                 .procname       = "scons-poweroff",
 474                 .data           = &scons_pwroff,
 475                 .maxlen         = sizeof (int),
 476                 .mode           = 0644,
 477                 .proc_handler   = proc_dointvec,
 478         },
 479 #endif
 480 #ifdef CONFIG_SPARC64
 481         {
 482                 .procname       = "tsb-ratio",
 483                 .data           = &sysctl_tsb_ratio,
 484                 .maxlen         = sizeof (int),
 485                 .mode           = 0644,
 486                 .proc_handler   = proc_dointvec,
 487         },
 488 #endif
 489 #ifdef __hppa__
 490         {
 491                 .procname       = "soft-power",
 492                 .data           = &pwrsw_enabled,
 493                 .maxlen         = sizeof (int),
 494                 .mode           = 0644,
 495                 .proc_handler   = proc_dointvec,
 496         },
 497         {
 498                 .procname       = "unaligned-trap",
 499                 .data           = &unaligned_enabled,
 500                 .maxlen         = sizeof (int),
 501                 .mode           = 0644,
 502                 .proc_handler   = proc_dointvec,
 503         },
 504 #endif
 505         {
 506                 .procname       = "ctrl-alt-del",
 507                 .data           = &C_A_D,
 508                 .maxlen         = sizeof(int),
 509                 .mode           = 0644,
 510                 .proc_handler   = proc_dointvec,
 511         },
 512 #ifdef CONFIG_FUNCTION_TRACER
 513         {
 514                 .procname       = "ftrace_enabled",
 515                 .data           = &ftrace_enabled,
 516                 .maxlen         = sizeof(int),
 517                 .mode           = 0644,
 518                 .proc_handler   = ftrace_enable_sysctl,
 519         },
 520 #endif
 521 #ifdef CONFIG_STACK_TRACER
 522         {
 523                 .procname       = "stack_tracer_enabled",
 524                 .data           = &stack_tracer_enabled,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = stack_trace_sysctl,
 528         },
 529 #endif
 530 #ifdef CONFIG_TRACING
 531         {
 532                 .procname       = "ftrace_dump_on_oops",
 533                 .data           = &ftrace_dump_on_oops,
 534                 .maxlen         = sizeof(int),
 535                 .mode           = 0644,
 536                 .proc_handler   = proc_dointvec,
 537         },
 538 #endif
 539 #ifdef CONFIG_MODULES
 540         {
 541                 .procname       = "modprobe",
 542                 .data           = &modprobe_path,
 543                 .maxlen         = KMOD_PATH_LEN,
 544                 .mode           = 0644,
 545                 .proc_handler   = proc_dostring,
 546         },
 547         {
 548                 .procname       = "modules_disabled",
 549                 .data           = &modules_disabled,
 550                 .maxlen         = sizeof(int),
 551                 .mode           = 0644,
 552                 /* only handle a transition from default "0" to "1" */
 553                 .proc_handler   = proc_dointvec_minmax,
 554                 .extra1         = &one,
 555                 .extra2         = &one,
 556         },
 557 #endif
 558 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 559         {
 560                 .procname       = "hotplug",
 561                 .data           = &uevent_helper,
 562                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 563                 .mode           = 0644,
 564                 .proc_handler   = proc_dostring,
 565         },
 566 #endif
 567 #ifdef CONFIG_CHR_DEV_SG
 568         {
 569                 .procname       = "sg-big-buff",
 570                 .data           = &sg_big_buff,
 571                 .maxlen         = sizeof (int),
 572                 .mode           = 0444,
 573                 .proc_handler   = proc_dointvec,
 574         },
 575 #endif
 576 #ifdef CONFIG_BSD_PROCESS_ACCT
 577         {
 578                 .procname       = "acct",
 579                 .data           = &acct_parm,
 580                 .maxlen         = 3*sizeof(int),
 581                 .mode           = 0644,
 582                 .proc_handler   = proc_dointvec,
 583         },
 584 #endif
 585 #ifdef CONFIG_MAGIC_SYSRQ
 586         {
 587                 .procname       = "sysrq",
 588                 .data           = &__sysrq_enabled,
 589                 .maxlen         = sizeof (int),
 590                 .mode           = 0644,
 591                 .proc_handler   = sysrq_sysctl_handler,
 592         },
 593 #endif
 594 #ifdef CONFIG_PROC_SYSCTL
 595         {
 596                 .procname       = "cad_pid",
 597                 .data           = NULL,
 598                 .maxlen         = sizeof (int),
 599                 .mode           = 0600,
 600                 .proc_handler   = proc_do_cad_pid,
 601         },
 602 #endif
 603         {
 604                 .procname       = "threads-max",
 605                 .data           = &max_threads,
 606                 .maxlen         = sizeof(int),
 607                 .mode           = 0644,
 608                 .proc_handler   = proc_dointvec,
 609         },
 610         {
 611                 .procname       = "random",
 612                 .mode           = 0555,
 613                 .child          = random_table,
 614         },
 615         {
 616                 .procname       = "overflowuid",
 617                 .data           = &overflowuid,
 618                 .maxlen         = sizeof(int),
 619                 .mode           = 0644,
 620                 .proc_handler   = proc_dointvec_minmax,
 621                 .extra1         = &minolduid,
 622                 .extra2         = &maxolduid,
 623         },
 624         {
 625                 .procname       = "overflowgid",
 626                 .data           = &overflowgid,
 627                 .maxlen         = sizeof(int),
 628                 .mode           = 0644,
 629                 .proc_handler   = proc_dointvec_minmax,
 630                 .extra1         = &minolduid,
 631                 .extra2         = &maxolduid,
 632         },
 633 #ifdef CONFIG_S390
 634 #ifdef CONFIG_MATHEMU
 635         {
 636                 .procname       = "ieee_emulation_warnings",
 637                 .data           = &sysctl_ieee_emulation_warnings,
 638                 .maxlen         = sizeof(int),
 639                 .mode           = 0644,
 640                 .proc_handler   = proc_dointvec,
 641         },
 642 #endif
 643         {
 644                 .procname       = "userprocess_debug",
 645                 .data           = &show_unhandled_signals,
 646                 .maxlen         = sizeof(int),
 647                 .mode           = 0644,
 648                 .proc_handler   = proc_dointvec,
 649         },
 650 #endif
 651         {
 652                 .procname       = "pid_max",
 653                 .data           = &pid_max,
 654                 .maxlen         = sizeof (int),
 655                 .mode           = 0644,
 656                 .proc_handler   = proc_dointvec_minmax,
 657                 .extra1         = &pid_max_min,
 658                 .extra2         = &pid_max_max,
 659         },
 660         {
 661                 .procname       = "panic_on_oops",
 662                 .data           = &panic_on_oops,
 663                 .maxlen         = sizeof(int),
 664                 .mode           = 0644,
 665                 .proc_handler   = proc_dointvec,
 666         },
 667 #if defined CONFIG_PRINTK
 668         {
 669                 .procname       = "printk",
 670                 .data           = &console_loglevel,
 671                 .maxlen         = 4*sizeof(int),
 672                 .mode           = 0644,
 673                 .proc_handler   = proc_dointvec,
 674         },
 675         {
 676                 .procname       = "printk_ratelimit",
 677                 .data           = &printk_ratelimit_state.interval,
 678                 .maxlen         = sizeof(int),
 679                 .mode           = 0644,
 680                 .proc_handler   = proc_dointvec_jiffies,
 681         },
 682         {
 683                 .procname       = "printk_ratelimit_burst",
 684                 .data           = &printk_ratelimit_state.burst,
 685                 .maxlen         = sizeof(int),
 686                 .mode           = 0644,
 687                 .proc_handler   = proc_dointvec,
 688         },
 689         {
 690                 .procname       = "printk_delay",
 691                 .data           = &printk_delay_msec,
 692                 .maxlen         = sizeof(int),
 693                 .mode           = 0644,
 694                 .proc_handler   = proc_dointvec_minmax,
 695                 .extra1         = &zero,
 696                 .extra2         = &ten_thousand,
 697         },
 698 #endif
 699         {
 700                 .procname       = "ngroups_max",
 701                 .data           = &ngroups_max,
 702                 .maxlen         = sizeof (int),
 703                 .mode           = 0444,
 704                 .proc_handler   = proc_dointvec,
 705         },
 706 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 707         {
 708                 .procname       = "unknown_nmi_panic",
 709                 .data           = &unknown_nmi_panic,
 710                 .maxlen         = sizeof (int),
 711                 .mode           = 0644,
 712                 .proc_handler   = proc_dointvec,
 713         },
 714         {
 715                 .procname       = "nmi_watchdog",
 716                 .data           = &nmi_watchdog_enabled,
 717                 .maxlen         = sizeof (int),
 718                 .mode           = 0644,
 719                 .proc_handler   = proc_nmi_enabled,
 720         },
 721 #endif
 722 #if defined(CONFIG_X86)
 723         {
 724                 .procname       = "panic_on_unrecovered_nmi",
 725                 .data           = &panic_on_unrecovered_nmi,
 726                 .maxlen         = sizeof(int),
 727                 .mode           = 0644,
 728                 .proc_handler   = proc_dointvec,
 729         },
 730         {
 731                 .procname       = "panic_on_io_nmi",
 732                 .data           = &panic_on_io_nmi,
 733                 .maxlen         = sizeof(int),
 734                 .mode           = 0644,
 735                 .proc_handler   = proc_dointvec,
 736         },
 737         {
 738                 .procname       = "bootloader_type",
 739                 .data           = &bootloader_type,
 740                 .maxlen         = sizeof (int),
 741                 .mode           = 0444,
 742                 .proc_handler   = proc_dointvec,
 743         },
 744         {
 745                 .procname       = "bootloader_version",
 746                 .data           = &bootloader_version,
 747                 .maxlen         = sizeof (int),
 748                 .mode           = 0444,
 749                 .proc_handler   = proc_dointvec,
 750         },
 751         {
 752                 .procname       = "kstack_depth_to_print",
 753                 .data           = &kstack_depth_to_print,
 754                 .maxlen         = sizeof(int),
 755                 .mode           = 0644,
 756                 .proc_handler   = proc_dointvec,
 757         },
 758         {
 759                 .procname       = "io_delay_type",
 760                 .data           = &io_delay_type,
 761                 .maxlen         = sizeof(int),
 762                 .mode           = 0644,
 763                 .proc_handler   = proc_dointvec,
 764         },
 765 #endif
 766 #if defined(CONFIG_MMU)
 767         {
 768                 .procname       = "randomize_va_space",
 769                 .data           = &randomize_va_space,
 770                 .maxlen         = sizeof(int),
 771                 .mode           = 0644,
 772                 .proc_handler   = proc_dointvec,
 773         },
 774 #endif
 775 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 776         {
 777                 .procname       = "spin_retry",
 778                 .data           = &spin_retry,
 779                 .maxlen         = sizeof (int),
 780                 .mode           = 0644,
 781                 .proc_handler   = proc_dointvec,
 782         },
 783 #endif
 784 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 785         {
 786                 .procname       = "acpi_video_flags",
 787                 .data           = &acpi_realmode_flags,
 788                 .maxlen         = sizeof (unsigned long),
 789                 .mode           = 0644,
 790                 .proc_handler   = proc_doulongvec_minmax,
 791         },
 792 #endif
 793 #ifdef CONFIG_IA64
 794         {
 795                 .procname       = "ignore-unaligned-usertrap",
 796                 .data           = &no_unaligned_warning,
 797                 .maxlen         = sizeof (int),
 798                 .mode           = 0644,
 799                 .proc_handler   = proc_dointvec,
 800         },
 801         {
 802                 .procname       = "unaligned-dump-stack",
 803                 .data           = &unaligned_dump_stack,
 804                 .maxlen         = sizeof (int),
 805                 .mode           = 0644,
 806                 .proc_handler   = proc_dointvec,
 807         },
 808 #endif
 809 #ifdef CONFIG_DETECT_SOFTLOCKUP
 810         {
 811                 .procname       = "softlockup_panic",
 812                 .data           = &softlockup_panic,
 813                 .maxlen         = sizeof(int),
 814                 .mode           = 0644,
 815                 .proc_handler   = proc_dointvec_minmax,
 816                 .extra1         = &zero,
 817                 .extra2         = &one,
 818         },
 819         {
 820                 .procname       = "softlockup_thresh",
 821                 .data           = &softlockup_thresh,
 822                 .maxlen         = sizeof(int),
 823                 .mode           = 0644,
 824                 .proc_handler   = proc_dosoftlockup_thresh,
 825                 .extra1         = &neg_one,
 826                 .extra2         = &sixty,
 827         },
 828 #endif
 829 #ifdef CONFIG_DETECT_HUNG_TASK
 830         {
 831                 .procname       = "hung_task_panic",
 832                 .data           = &sysctl_hung_task_panic,
 833                 .maxlen         = sizeof(int),
 834                 .mode           = 0644,
 835                 .proc_handler   = proc_dointvec_minmax,
 836                 .extra1         = &zero,
 837                 .extra2         = &one,
 838         },
 839         {
 840                 .procname       = "hung_task_check_count",
 841                 .data           = &sysctl_hung_task_check_count,
 842                 .maxlen         = sizeof(unsigned long),
 843                 .mode           = 0644,
 844                 .proc_handler   = proc_doulongvec_minmax,
 845         },
 846         {
 847                 .procname       = "hung_task_timeout_secs",
 848                 .data           = &sysctl_hung_task_timeout_secs,
 849                 .maxlen         = sizeof(unsigned long),
 850                 .mode           = 0644,
 851                 .proc_handler   = proc_dohung_task_timeout_secs,
 852         },
 853         {
 854                 .procname       = "hung_task_warnings",
 855                 .data           = &sysctl_hung_task_warnings,
 856                 .maxlen         = sizeof(unsigned long),
 857                 .mode           = 0644,
 858                 .proc_handler   = proc_doulongvec_minmax,
 859         },
 860 #endif
 861 #ifdef CONFIG_COMPAT
 862         {
 863                 .procname       = "compat-log",
 864                 .data           = &compat_log,
 865                 .maxlen         = sizeof (int),
 866                 .mode           = 0644,
 867                 .proc_handler   = proc_dointvec,
 868         },
 869 #endif
 870 #ifdef CONFIG_RT_MUTEXES
 871         {
 872                 .procname       = "max_lock_depth",
 873                 .data           = &max_lock_depth,
 874                 .maxlen         = sizeof(int),
 875                 .mode           = 0644,
 876                 .proc_handler   = proc_dointvec,
 877         },
 878 #endif
 879         {
 880                 .procname       = "poweroff_cmd",
 881                 .data           = &poweroff_cmd,
 882                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 883                 .mode           = 0644,
 884                 .proc_handler   = proc_dostring,
 885         },
 886 #ifdef CONFIG_KEYS
 887         {
 888                 .procname       = "keys",
 889                 .mode           = 0555,
 890                 .child          = key_sysctls,
 891         },
 892 #endif
 893 #ifdef CONFIG_RCU_TORTURE_TEST
 894         {
 895                 .procname       = "rcutorture_runnable",
 896                 .data           = &rcutorture_runnable,
 897                 .maxlen         = sizeof(int),
 898                 .mode           = 0644,
 899                 .proc_handler   = proc_dointvec,
 900         },
 901 #endif
 902 #ifdef CONFIG_SLOW_WORK
 903         {
 904                 .procname       = "slow-work",
 905                 .mode           = 0555,
 906                 .child          = slow_work_sysctls,
 907         },
 908 #endif
 909 #ifdef CONFIG_PERF_EVENTS
 910         {
 911                 .procname       = "perf_event_paranoid",
 912                 .data           = &sysctl_perf_event_paranoid,
 913                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 914                 .mode           = 0644,
 915                 .proc_handler   = proc_dointvec,
 916         },
 917         {
 918                 .procname       = "perf_event_mlock_kb",
 919                 .data           = &sysctl_perf_event_mlock,
 920                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 921                 .mode           = 0644,
 922                 .proc_handler   = proc_dointvec,
 923         },
 924         {
 925                 .procname       = "perf_event_max_sample_rate",
 926                 .data           = &sysctl_perf_event_sample_rate,
 927                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 928                 .mode           = 0644,
 929                 .proc_handler   = proc_dointvec,
 930         },
 931 #endif
 932 #ifdef CONFIG_KMEMCHECK
 933         {
 934                 .procname       = "kmemcheck",
 935                 .data           = &kmemcheck_enabled,
 936                 .maxlen         = sizeof(int),
 937                 .mode           = 0644,
 938                 .proc_handler   = proc_dointvec,
 939         },
 940 #endif
 941 #ifdef CONFIG_BLOCK
 942         {
 943                 .procname       = "blk_iopoll",
 944                 .data           = &blk_iopoll_enabled,
 945                 .maxlen         = sizeof(int),
 946                 .mode           = 0644,
 947                 .proc_handler   = proc_dointvec,
 948         },
 949 #endif
 950 /*
 951  * NOTE: do not add new entries to this table unless you have read
 952  * Documentation/sysctl/ctl_unnumbered.txt
 953  */
 954         { }
 955 };
 956
 957 static struct ctl_table vm_table[] = {
 958         {
 959                 .procname       = "overcommit_memory",
 960                 .data           = &sysctl_overcommit_memory,
 961                 .maxlen         = sizeof(sysctl_overcommit_memory),
 962                 .mode           = 0644,
 963                 .proc_handler   = proc_dointvec,
 964         },
 965         {
 966                 .procname       = "panic_on_oom",
 967                 .data           = &sysctl_panic_on_oom,
 968                 .maxlen         = sizeof(sysctl_panic_on_oom),
 969                 .mode           = 0644,
 970                 .proc_handler   = proc_dointvec,
 971         },
 972         {
 973                 .procname       = "oom_kill_allocating_task",
 974                 .data           = &sysctl_oom_kill_allocating_task,
 975                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 976                 .mode           = 0644,
 977                 .proc_handler   = proc_dointvec,
 978         },
 979         {
 980                 .procname       = "oom_dump_tasks",
 981                 .data           = &sysctl_oom_dump_tasks,
 982                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 983                 .mode           = 0644,
 984                 .proc_handler   = proc_dointvec,
 985         },
 986         {
 987                 .procname       = "overcommit_ratio",
 988                 .data           = &sysctl_overcommit_ratio,
 989                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 990                 .mode           = 0644,
 991                 .proc_handler   = proc_dointvec,
 992         },
 993         {
 994                 .procname       = "page-cluster",
 995                 .data           = &page_cluster,
 996                 .maxlen         = sizeof(int),
 997                 .mode           = 0644,
 998                 .proc_handler   = proc_dointvec,
 999         },
1000         {
1001                 .procname       = "dirty_background_ratio",
1002                 .data           = &dirty_background_ratio,
1003                 .maxlen         = sizeof(dirty_background_ratio),
1004                 .mode           = 0644,
1005                 .proc_handler   = dirty_background_ratio_handler,
1006                 .extra1         = &zero,
1007                 .extra2         = &one_hundred,
1008         },
1009         {
1010                 .procname       = "dirty_background_bytes",
1011                 .data           = &dirty_background_bytes,
1012                 .maxlen         = sizeof(dirty_background_bytes),
1013                 .mode           = 0644,
1014                 .proc_handler   = dirty_background_bytes_handler,
1015                 .extra1         = &one_ul,
1016         },
1017         {
1018                 .procname       = "dirty_ratio",
1019                 .data           = &vm_dirty_ratio,
1020                 .maxlen         = sizeof(vm_dirty_ratio),
1021                 .mode           = 0644,
1022                 .proc_handler   = dirty_ratio_handler,
1023                 .extra1         = &zero,
1024                 .extra2         = &one_hundred,
1025         },
1026         {
1027                 .procname       = "dirty_bytes",
1028                 .data           = &vm_dirty_bytes,
1029                 .maxlen         = sizeof(vm_dirty_bytes),
1030                 .mode           = 0644,
1031                 .proc_handler   = dirty_bytes_handler,
1032                 .extra1         = &dirty_bytes_min,
1033         },
1034         {
1035                 .procname       = "dirty_writeback_centisecs",
1036                 .data           = &dirty_writeback_interval,
1037                 .maxlen         = sizeof(dirty_writeback_interval),
1038                 .mode           = 0644,
1039                 .proc_handler   = dirty_writeback_centisecs_handler,
1040         },
1041         {
1042                 .procname       = "dirty_expire_centisecs",
1043                 .data           = &dirty_expire_interval,
1044                 .maxlen         = sizeof(dirty_expire_interval),
1045                 .mode           = 0644,
1046                 .proc_handler   = proc_dointvec,
1047         },
1048         {
1049                 .procname       = "nr_pdflush_threads",
1050                 .data           = &nr_pdflush_threads,
1051                 .maxlen         = sizeof nr_pdflush_threads,
1052                 .mode           = 0444 /* read-only*/,
1053                 .proc_handler   = proc_dointvec,
1054         },
1055         {
1056                 .procname       = "swappiness",
1057                 .data           = &vm_swappiness,
1058                 .maxlen         = sizeof(vm_swappiness),
1059                 .mode           = 0644,
1060                 .proc_handler   = proc_dointvec_minmax,
1061                 .extra1         = &zero,
1062                 .extra2         = &one_hundred,
1063         },
1064 #ifdef CONFIG_HUGETLB_PAGE
1065         {
1066                 .procname       = "nr_hugepages",
1067                 .data           = NULL,
1068                 .maxlen         = sizeof(unsigned long),
1069                 .mode           = 0644,
1070                 .proc_handler   = hugetlb_sysctl_handler,
1071                 .extra1         = (void *)&hugetlb_zero,
1072                 .extra2         = (void *)&hugetlb_infinity,
1073         },
1074 #ifdef CONFIG_NUMA
1075         {
1076                 .procname       = "nr_hugepages_mempolicy",
1077                 .data           = NULL,
1078                 .maxlen         = sizeof(unsigned long),
1079                 .mode           = 0644,
1080                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1081                 .extra1         = (void *)&hugetlb_zero,
1082                 .extra2         = (void *)&hugetlb_infinity,
1083         },
1084 #endif
1085          {
1086                 .procname       = "hugetlb_shm_group",
1087                 .data           = &sysctl_hugetlb_shm_group,
1088                 .maxlen         = sizeof(gid_t),
1089                 .mode           = 0644,
1090                 .proc_handler   = proc_dointvec,
1091          },
1092          {
1093                 .procname       = "hugepages_treat_as_movable",
1094                 .data           = &hugepages_treat_as_movable,
1095                 .maxlen         = sizeof(int),
1096                 .mode           = 0644,
1097                 .proc_handler   = hugetlb_treat_movable_handler,
1098         },
1099         {
1100                 .procname       = "nr_overcommit_hugepages",
1101                 .data           = NULL,
1102                 .maxlen         = sizeof(unsigned long),
1103                 .mode           = 0644,
1104                 .proc_handler   = hugetlb_overcommit_handler,
1105                 .extra1         = (void *)&hugetlb_zero,
1106                 .extra2         = (void *)&hugetlb_infinity,
1107         },
1108 #endif
1109         {
1110                 .procname       = "lowmem_reserve_ratio",
1111                 .data           = &sysctl_lowmem_reserve_ratio,
1112                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1113                 .mode           = 0644,
1114                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1115         },
1116         {
1117                 .procname       = "drop_caches",
1118                 .data           = &sysctl_drop_caches,
1119                 .maxlen         = sizeof(int),
1120                 .mode           = 0644,
1121                 .proc_handler   = drop_caches_sysctl_handler,
1122         },
1123         {
1124                 .procname       = "min_free_kbytes",
1125                 .data           = &min_free_kbytes,
1126                 .maxlen         = sizeof(min_free_kbytes),
1127                 .mode           = 0644,
1128                 .proc_handler   = min_free_kbytes_sysctl_handler,
1129                 .extra1         = &zero,
1130         },
1131         {
1132                 .procname       = "percpu_pagelist_fraction",
1133                 .data           = &percpu_pagelist_fraction,
1134                 .maxlen         = sizeof(percpu_pagelist_fraction),
1135                 .mode           = 0644,
1136                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1137                 .extra1         = &min_percpu_pagelist_fract,
1138         },
1139 #ifdef CONFIG_MMU
1140         {
1141                 .procname       = "max_map_count",
1142                 .data           = &sysctl_max_map_count,
1143                 .maxlen         = sizeof(sysctl_max_map_count),
1144                 .mode           = 0644,
1145                 .proc_handler   = proc_dointvec_minmax,
1146                 .extra1         = &zero,
1147         },
1148 #else
1149         {
1150                 .procname       = "nr_trim_pages",
1151                 .data           = &sysctl_nr_trim_pages,
1152                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1153                 .mode           = 0644,
1154                 .proc_handler   = proc_dointvec_minmax,
1155                 .extra1         = &zero,
1156         },
1157 #endif
1158         {
1159                 .procname       = "laptop_mode",
1160                 .data           = &laptop_mode,
1161                 .maxlen         = sizeof(laptop_mode),
1162                 .mode           = 0644,
1163                 .proc_handler   = proc_dointvec_jiffies,
1164         },
1165         {
1166                 .procname       = "block_dump",
1167                 .data           = &block_dump,
1168                 .maxlen         = sizeof(block_dump),
1169                 .mode           = 0644,
1170                 .proc_handler   = proc_dointvec,
1171                 .extra1         = &zero,
1172         },
1173         {
1174                 .procname       = "vfs_cache_pressure",
1175                 .data           = &sysctl_vfs_cache_pressure,
1176                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1177                 .mode           = 0644,
1178                 .proc_handler   = proc_dointvec,
1179                 .extra1         = &zero,
1180         },
1181 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1182         {
1183                 .procname       = "legacy_va_layout",
1184                 .data           = &sysctl_legacy_va_layout,
1185                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1186                 .mode           = 0644,
1187                 .proc_handler   = proc_dointvec,
1188                 .extra1         = &zero,
1189         },
1190 #endif
1191 #ifdef CONFIG_NUMA
1192         {
1193                 .procname       = "zone_reclaim_mode",
1194                 .data           = &zone_reclaim_mode,
1195                 .maxlen         = sizeof(zone_reclaim_mode),
1196                 .mode           = 0644,
1197                 .proc_handler   = proc_dointvec,
1198                 .extra1         = &zero,
1199         },
1200         {
1201                 .procname       = "min_unmapped_ratio",
1202                 .data           = &sysctl_min_unmapped_ratio,
1203                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1204                 .mode           = 0644,
1205                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1206                 .extra1         = &zero,
1207                 .extra2         = &one_hundred,
1208         },
1209         {
1210                 .procname       = "min_slab_ratio",
1211                 .data           = &sysctl_min_slab_ratio,
1212                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1213                 .mode           = 0644,
1214                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1215                 .extra1         = &zero,
1216                 .extra2         = &one_hundred,
1217         },
1218 #endif
1219 #ifdef CONFIG_SMP
1220         {
1221                 .procname       = "stat_interval",
1222                 .data           = &sysctl_stat_interval,
1223                 .maxlen         = sizeof(sysctl_stat_interval),
1224                 .mode           = 0644,
1225                 .proc_handler   = proc_dointvec_jiffies,
1226         },
1227 #endif
1228 #ifdef CONFIG_MMU
1229         {
1230                 .procname       = "mmap_min_addr",
1231                 .data           = &dac_mmap_min_addr,
1232                 .maxlen         = sizeof(unsigned long),
1233                 .mode           = 0644,
1234                 .proc_handler   = mmap_min_addr_handler,
1235         },
1236 #endif
1237 #ifdef CONFIG_NUMA
1238         {
1239                 .procname       = "numa_zonelist_order",
1240                 .data           = &numa_zonelist_order,
1241                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1242                 .mode           = 0644,
1243                 .proc_handler   = numa_zonelist_order_handler,
1244         },
1245 #endif
1246 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1247    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1248         {
1249                 .procname       = "vdso_enabled",
1250                 .data           = &vdso_enabled,
1251                 .maxlen         = sizeof(vdso_enabled),
1252                 .mode           = 0644,
1253                 .proc_handler   = proc_dointvec,
1254                 .extra1         = &zero,
1255         },
1256 #endif
1257 #ifdef CONFIG_HIGHMEM
1258         {
1259                 .procname       = "highmem_is_dirtyable",
1260                 .data           = &vm_highmem_is_dirtyable,
1261                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1262                 .mode           = 0644,
1263                 .proc_handler   = proc_dointvec_minmax,
1264                 .extra1         = &zero,
1265                 .extra2         = &one,
1266         },
1267 #endif
1268         {
1269                 .procname       = "scan_unevictable_pages",
1270                 .data           = &scan_unevictable_pages,
1271                 .maxlen         = sizeof(scan_unevictable_pages),
1272                 .mode           = 0644,
1273                 .proc_handler   = scan_unevictable_handler,
1274         },
1275 #ifdef CONFIG_MEMORY_FAILURE
1276         {
1277                 .procname       = "memory_failure_early_kill",
1278                 .data           = &sysctl_memory_failure_early_kill,
1279                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1280                 .mode           = 0644,
1281                 .proc_handler   = proc_dointvec_minmax,
1282                 .extra1         = &zero,
1283                 .extra2         = &one,
1284         },
1285         {
1286                 .procname       = "memory_failure_recovery",
1287                 .data           = &sysctl_memory_failure_recovery,
1288                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1289                 .mode           = 0644,
1290                 .proc_handler   = proc_dointvec_minmax,
1291                 .extra1         = &zero,
1292                 .extra2         = &one,
1293         },
1294 #endif
1295
1296 /*
1297  * NOTE: do not add new entries to this table unless you have read
1298  * Documentation/sysctl/ctl_unnumbered.txt
1299  */
1300         { }
1301 };
1302
1303 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1304 static struct ctl_table binfmt_misc_table[] = {
1305         { }
1306 };
1307 #endif
1308
1309 static struct ctl_table fs_table[] = {
1310         {
1311                 .procname       = "inode-nr",
1312                 .data           = &inodes_stat,
1313                 .maxlen         = 2*sizeof(int),
1314                 .mode           = 0444,
1315                 .proc_handler   = proc_dointvec,
1316         },
1317         {
1318                 .procname       = "inode-state",
1319                 .data           = &inodes_stat,
1320                 .maxlen         = 7*sizeof(int),
1321                 .mode           = 0444,
1322                 .proc_handler   = proc_dointvec,
1323         },
1324         {
1325                 .procname       = "file-nr",
1326                 .data           = &files_stat,
1327                 .maxlen         = 3*sizeof(int),
1328                 .mode           = 0444,
1329                 .proc_handler   = proc_nr_files,
1330         },
1331         {
1332                 .procname       = "file-max",
1333                 .data           = &files_stat.max_files,
1334                 .maxlen         = sizeof(int),
1335                 .mode           = 0644,
1336                 .proc_handler   = proc_dointvec,
1337         },
1338         {
1339                 .procname       = "nr_open",
1340                 .data           = &sysctl_nr_open,
1341                 .maxlen         = sizeof(int),
1342                 .mode           = 0644,
1343                 .proc_handler   = proc_dointvec_minmax,
1344                 .extra1         = &sysctl_nr_open_min,
1345                 .extra2         = &sysctl_nr_open_max,
1346         },
1347         {
1348                 .procname       = "dentry-state",
1349                 .data           = &dentry_stat,
1350                 .maxlen         = 6*sizeof(int),
1351                 .mode           = 0444,
1352                 .proc_handler   = proc_dointvec,
1353         },
1354         {
1355                 .procname       = "overflowuid",
1356                 .data           = &fs_overflowuid,
1357                 .maxlen         = sizeof(int),
1358                 .mode           = 0644,
1359                 .proc_handler   = proc_dointvec_minmax,
1360                 .extra1         = &minolduid,
1361                 .extra2         = &maxolduid,
1362         },
1363         {
1364                 .procname       = "overflowgid",
1365                 .data           = &fs_overflowgid,
1366                 .maxlen         = sizeof(int),
1367                 .mode           = 0644,
1368                 .proc_handler   = proc_dointvec_minmax,
1369                 .extra1         = &minolduid,
1370                 .extra2         = &maxolduid,
1371         },
1372 #ifdef CONFIG_FILE_LOCKING
1373         {
1374                 .procname       = "leases-enable",
1375                 .data           = &leases_enable,
1376                 .maxlen         = sizeof(int),
1377                 .mode           = 0644,
1378                 .proc_handler   = proc_dointvec,
1379         },
1380 #endif
1381 #ifdef CONFIG_DNOTIFY
1382         {
1383                 .procname       = "dir-notify-enable",
1384                 .data           = &dir_notify_enable,
1385                 .maxlen         = sizeof(int),
1386                 .mode           = 0644,
1387                 .proc_handler   = proc_dointvec,
1388         },
1389 #endif
1390 #ifdef CONFIG_MMU
1391 #ifdef CONFIG_FILE_LOCKING
1392         {
1393                 .procname       = "lease-break-time",
1394                 .data           = &lease_break_time,
1395                 .maxlen         = sizeof(int),
1396                 .mode           = 0644,
1397                 .proc_handler   = proc_dointvec,
1398         },
1399 #endif
1400 #ifdef CONFIG_AIO
1401         {
1402                 .procname       = "aio-nr",
1403                 .data           = &aio_nr,
1404                 .maxlen         = sizeof(aio_nr),
1405                 .mode           = 0444,
1406                 .proc_handler   = proc_doulongvec_minmax,
1407         },
1408         {
1409                 .procname       = "aio-max-nr",
1410                 .data           = &aio_max_nr,
1411                 .maxlen         = sizeof(aio_max_nr),
1412                 .mode           = 0644,
1413                 .proc_handler   = proc_doulongvec_minmax,
1414         },
1415 #endif /* CONFIG_AIO */
1416 #ifdef CONFIG_INOTIFY_USER
1417         {
1418                 .procname       = "inotify",
1419                 .mode           = 0555,
1420                 .child          = inotify_table,
1421         },
1422 #endif
1423 #ifdef CONFIG_EPOLL
1424         {
1425                 .procname       = "epoll",
1426                 .mode           = 0555,
1427                 .child          = epoll_table,
1428         },
1429 #endif
1430 #endif
1431         {
1432                 .procname       = "suid_dumpable",
1433                 .data           = &suid_dumpable,
1434                 .maxlen         = sizeof(int),
1435                 .mode           = 0644,
1436                 .proc_handler   = proc_dointvec_minmax,
1437                 .extra1         = &zero,
1438                 .extra2         = &two,
1439         },
1440 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1441         {
1442                 .procname       = "binfmt_misc",
1443                 .mode           = 0555,
1444                 .child          = binfmt_misc_table,
1445         },
1446 #endif
1447 /*
1448  * NOTE: do not add new entries to this table unless you have read
1449  * Documentation/sysctl/ctl_unnumbered.txt
1450  */
1451         { }
1452 };
1453
1454 static struct ctl_table debug_table[] = {
1455 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1456     defined(CONFIG_S390)
1457         {
1458                 .procname       = "exception-trace",
1459                 .data           = &show_unhandled_signals,
1460                 .maxlen         = sizeof(int),
1461                 .mode           = 0644,
1462                 .proc_handler   = proc_dointvec
1463         },
1464 #endif
1465 #if defined(CONFIG_OPTPROBES)
1466         {
1467                 .procname       = "kprobes-optimization",
1468                 .data           = &sysctl_kprobes_optimization,
1469                 .maxlen         = sizeof(int),
1470                 .mode           = 0644,
1471                 .proc_handler   = proc_kprobes_optimization_handler,
1472                 .extra1         = &zero,
1473                 .extra2         = &one,
1474         },
1475 #endif
1476         { }
1477 };
1478
1479 static struct ctl_table dev_table[] = {
1480         { }
1481 };
1482
1483 static DEFINE_SPINLOCK(sysctl_lock);
1484
1485 /* called under sysctl_lock */
1486 static int use_table(struct ctl_table_header *p)
1487 {
1488         if (unlikely(p->unregistering))
1489                 return 0;
1490         p->used++;
1491         return 1;
1492 }
1493
1494 /* called under sysctl_lock */
1495 static void unuse_table(struct ctl_table_header *p)
1496 {
1497         if (!--p->used)
1498                 if (unlikely(p->unregistering))
1499                         complete(p->unregistering);
1500 }
1501
1502 /* called under sysctl_lock, will reacquire if has to wait */
1503 static void start_unregistering(struct ctl_table_header *p)
1504 {
1505         /*
1506          * if p->used is 0, nobody will ever touch that entry again;
1507          * we'll eliminate all paths to it before dropping sysctl_lock
1508          */
1509         if (unlikely(p->used)) {
1510                 struct completion wait;
1511                 init_completion(&wait);
1512                 p->unregistering = &wait;
1513                 spin_unlock(&sysctl_lock);
1514                 wait_for_completion(&wait);
1515                 spin_lock(&sysctl_lock);
1516         } else {
1517                 /* anything non-NULL; we'll never dereference it */
1518                 p->unregistering = ERR_PTR(-EINVAL);
1519         }
1520         /*
1521          * do not remove from the list until nobody holds it; walking the
1522          * list in do_sysctl() relies on that.
1523          */
1524         list_del_init(&p->ctl_entry);
1525 }
1526
1527 void sysctl_head_get(struct ctl_table_header *head)
1528 {
1529         spin_lock(&sysctl_lock);
1530         head->count++;
1531         spin_unlock(&sysctl_lock);
1532 }
1533
1534 void sysctl_head_put(struct ctl_table_header *head)
1535 {
1536         spin_lock(&sysctl_lock);
1537         if (!--head->count)
1538                 kfree(head);
1539         spin_unlock(&sysctl_lock);
1540 }
1541
1542 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1543 {
1544         if (!head)
1545                 BUG();
1546         spin_lock(&sysctl_lock);
1547         if (!use_table(head))
1548                 head = ERR_PTR(-ENOENT);
1549         spin_unlock(&sysctl_lock);
1550         return head;
1551 }
1552
1553 void sysctl_head_finish(struct ctl_table_header *head)
1554 {
1555         if (!head)
1556                 return;
1557         spin_lock(&sysctl_lock);
1558         unuse_table(head);
1559         spin_unlock(&sysctl_lock);
1560 }
1561
1562 static struct ctl_table_set *
1563 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1564 {
1565         struct ctl_table_set *set = &root->default_set;
1566         if (root->lookup)
1567                 set = root->lookup(root, namespaces);
1568         return set;
1569 }
1570
1571 static struct list_head *
1572 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1573 {
1574         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1575         return &set->list;
1576 }
1577
1578 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1579                                             struct ctl_table_header *prev)
1580 {
1581         struct ctl_table_root *root;
1582         struct list_head *header_list;
1583         struct ctl_table_header *head;
1584         struct list_head *tmp;
1585
1586         spin_lock(&sysctl_lock);
1587         if (prev) {
1588                 head = prev;
1589                 tmp = &prev->ctl_entry;
1590                 unuse_table(prev);
1591                 goto next;
1592         }
1593         tmp = &root_table_header.ctl_entry;
1594         for (;;) {
1595                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1596
1597                 if (!use_table(head))
1598                         goto next;
1599                 spin_unlock(&sysctl_lock);
1600                 return head;
1601         next:
1602                 root = head->root;
1603                 tmp = tmp->next;
1604                 header_list = lookup_header_list(root, namespaces);
1605                 if (tmp != header_list)
1606                         continue;
1607
1608                 do {
1609                         root = list_entry(root->root_list.next,
1610                                         struct ctl_table_root, root_list);
1611                         if (root == &sysctl_table_root)
1612                                 goto out;
1613                         header_list = lookup_header_list(root, namespaces);
1614                 } while (list_empty(header_list));
1615                 tmp = header_list->next;
1616         }
1617 out:
1618         spin_unlock(&sysctl_lock);
1619         return NULL;
1620 }
1621
1622 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1623 {
1624         return __sysctl_head_next(current->nsproxy, prev);
1625 }
1626
1627 void register_sysctl_root(struct ctl_table_root *root)
1628 {
1629         spin_lock(&sysctl_lock);
1630         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1631         spin_unlock(&sysctl_lock);
1632 }
1633
1634 /*
1635  * sysctl_perm does NOT grant the superuser all rights automatically, because
1636  * some sysctl variables are readonly even to root.
1637  */
1638
1639 static int test_perm(int mode, int op)
1640 {
1641         if (!current_euid())
1642                 mode >>= 6;
1643         else if (in_egroup_p(0))
1644                 mode >>= 3;
1645         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1646                 return 0;
1647         return -EACCES;
1648 }
1649
1650 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1651 {
1652         int error;
1653         int mode;
1654
1655         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1656         if (error)
1657                 return error;
1658
1659         if (root->permissions)
1660                 mode = root->permissions(root, current->nsproxy, table);
1661         else
1662                 mode = table->mode;
1663
1664         return test_perm(mode, op);
1665 }
1666
1667 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1668 {
1669         for (; table->procname; table++) {
1670                 table->parent = parent;
1671                 if (table->child)
1672                         sysctl_set_parent(table, table->child);
1673         }
1674 }
1675
1676 static __init int sysctl_init(void)
1677 {
1678         sysctl_set_parent(NULL, root_table);
1679 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1680         {
1681                 int err;
1682                 err = sysctl_check_table(current->nsproxy, root_table);
1683         }
1684 #endif
1685         return 0;
1686 }
1687
1688 core_initcall(sysctl_init);
1689
1690 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1691                                       struct ctl_table *table)
1692 {
1693         struct ctl_table *p;
1694         const char *s = branch->procname;
1695
1696         /* branch should have named subdirectory as its first element */
1697         if (!s || !branch->child)
1698                 return NULL;
1699
1700         /* ... and nothing else */
1701         if (branch[1].procname)
1702                 return NULL;
1703
1704         /* table should contain subdirectory with the same name */
1705         for (p = table; p->procname; p++) {
1706                 if (!p->child)
1707                         continue;
1708                 if (p->procname && strcmp(p->procname, s) == 0)
1709                         return p;
1710         }
1711         return NULL;
1712 }
1713
1714 /* see if attaching q to p would be an improvement */
1715 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1716 {
1717         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1718         struct ctl_table *next;
1719         int is_better = 0;
1720         int not_in_parent = !p->attached_by;
1721
1722         while ((next = is_branch_in(by, to)) != NULL) {
1723                 if (by == q->attached_by)
1724                         is_better = 1;
1725                 if (to == p->attached_by)
1726                         not_in_parent = 1;
1727                 by = by->child;
1728                 to = next->child;
1729         }
1730
1731         if (is_better && not_in_parent) {
1732                 q->attached_by = by;
1733                 q->attached_to = to;
1734                 q->parent = p;
1735         }
1736 }
1737
1738 /**
1739  * __register_sysctl_paths - register a sysctl hierarchy
1740  * @root: List of sysctl headers to register on
1741  * @namespaces: Data to compute which lists of sysctl entries are visible
1742  * @path: The path to the directory the sysctl table is in.
1743  * @table: the top-level table structure
1744  *
1745  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1746  * array. A completely 0 filled entry terminates the table.
1747  *
1748  * The members of the &struct ctl_table structure are used as follows:
1749  *
1750  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1751  *            enter a sysctl file
1752  *
1753  * data - a pointer to data for use by proc_handler
1754  *
1755  * maxlen - the maximum size in bytes of the data
1756  *
1757  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1758  *
1759  * child - a pointer to the child sysctl table if this entry is a directory, or
1760  *         %NULL.
1761  *
1762  * proc_handler - the text handler routine (described below)
1763  *
1764  * de - for internal use by the sysctl routines
1765  *
1766  * extra1, extra2 - extra pointers usable by the proc handler routines
1767  *
1768  * Leaf nodes in the sysctl tree will be represented by a single file
1769  * under /proc; non-leaf nodes will be represented by directories.
1770  *
1771  * sysctl(2) can automatically manage read and write requests through
1772  * the sysctl table.  The data and maxlen fields of the ctl_table
1773  * struct enable minimal validation of the values being written to be
1774  * performed, and the mode field allows minimal authentication.
1775  *
1776  * There must be a proc_handler routine for any terminal nodes
1777  * mirrored under /proc/sys (non-terminals are handled by a built-in
1778  * directory handler).  Several default handlers are available to
1779  * cover common cases -
1780  *
1781  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1782  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1783  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1784  *
1785  * It is the handler's job to read the input buffer from user memory
1786  * and process it. The handler should return 0 on success.
1787  *
1788  * This routine returns %NULL on a failure to register, and a pointer
1789  * to the table header on success.
1790  */
1791 struct ctl_table_header *__register_sysctl_paths(
1792         struct ctl_table_root *root,
1793         struct nsproxy *namespaces,
1794         const struct ctl_path *path, struct ctl_table *table)
1795 {
1796         struct ctl_table_header *header;
1797         struct ctl_table *new, **prevp;
1798         unsigned int n, npath;
1799         struct ctl_table_set *set;
1800
1801         /* Count the path components */
1802         for (npath = 0; path[npath].procname; ++npath)
1803                 ;
1804
1805         /*
1806          * For each path component, allocate a 2-element ctl_table array.
1807          * The first array element will be filled with the sysctl entry
1808          * for this, the second will be the sentinel (procname == 0).
1809          *
1810          * We allocate everything in one go so that we don't have to
1811          * worry about freeing additional memory in unregister_sysctl_table.
1812          */
1813         header = kzalloc(sizeof(struct ctl_table_header) +
1814                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1815         if (!header)
1816                 return NULL;
1817
1818         new = (struct ctl_table *) (header + 1);
1819
1820         /* Now connect the dots */
1821         prevp = &header->ctl_table;
1822         for (n = 0; n < npath; ++n, ++path) {
1823                 /* Copy the procname */
1824                 new->procname = path->procname;
1825                 new->mode     = 0555;
1826
1827                 *prevp = new;
1828                 prevp = &new->child;
1829
1830                 new += 2;
1831         }
1832         *prevp = table;
1833         header->ctl_table_arg = table;
1834
1835         INIT_LIST_HEAD(&header->ctl_entry);
1836         header->used = 0;
1837         header->unregistering = NULL;
1838         header->root = root;
1839         sysctl_set_parent(NULL, header->ctl_table);
1840         header->count = 1;
1841 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1842         if (sysctl_check_table(namespaces, header->ctl_table)) {
1843                 kfree(header);
1844                 return NULL;
1845         }
1846 #endif
1847         spin_lock(&sysctl_lock);
1848         header->set = lookup_header_set(root, namespaces);
1849         header->attached_by = header->ctl_table;
1850         header->attached_to = root_table;
1851         header->parent = &root_table_header;
1852         for (set = header->set; set; set = set->parent) {
1853                 struct ctl_table_header *p;
1854                 list_for_each_entry(p, &set->list, ctl_entry) {
1855                         if (p->unregistering)
1856                                 continue;
1857                         try_attach(p, header);
1858                 }
1859         }
1860         header->parent->count++;
1861         list_add_tail(&header->ctl_entry, &header->set->list);
1862         spin_unlock(&sysctl_lock);
1863
1864         return header;
1865 }
1866
1867 /**
1868  * register_sysctl_table_path - register a sysctl table hierarchy
1869  * @path: The path to the directory the sysctl table is in.
1870  * @table: the top-level table structure
1871  *
1872  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1873  * array. A completely 0 filled entry terminates the table.
1874  *
1875  * See __register_sysctl_paths for more details.
1876  */
1877 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1878                                                 struct ctl_table *table)
1879 {
1880         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1881                                         path, table);
1882 }
1883
1884 /**
1885  * register_sysctl_table - register a sysctl table hierarchy
1886  * @table: the top-level table structure
1887  *
1888  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1889  * array. A completely 0 filled entry terminates the table.
1890  *
1891  * See register_sysctl_paths for more details.
1892  */
1893 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1894 {
1895         static const struct ctl_path null_path[] = { {} };
1896
1897         return register_sysctl_paths(null_path, table);
1898 }
1899
1900 /**
1901  * unregister_sysctl_table - unregister a sysctl table hierarchy
1902  * @header: the header returned from register_sysctl_table
1903  *
1904  * Unregisters the sysctl table and all children. proc entries may not
1905  * actually be removed until they are no longer used by anyone.
1906  */
1907 void unregister_sysctl_table(struct ctl_table_header * header)
1908 {
1909         might_sleep();
1910
1911         if (header == NULL)
1912                 return;
1913
1914         spin_lock(&sysctl_lock);
1915         start_unregistering(header);
1916         if (!--header->parent->count) {
1917                 WARN_ON(1);
1918                 kfree(header->parent);
1919         }
1920         if (!--header->count)
1921                 kfree(header);
1922         spin_unlock(&sysctl_lock);
1923 }
1924
1925 int sysctl_is_seen(struct ctl_table_header *p)
1926 {
1927         struct ctl_table_set *set = p->set;
1928         int res;
1929         spin_lock(&sysctl_lock);
1930         if (p->unregistering)
1931                 res = 0;
1932         else if (!set->is_seen)
1933                 res = 1;
1934         else
1935                 res = set->is_seen(set);
1936         spin_unlock(&sysctl_lock);
1937         return res;
1938 }
1939
1940 void setup_sysctl_set(struct ctl_table_set *p,
1941         struct ctl_table_set *parent,
1942         int (*is_seen)(struct ctl_table_set *))
1943 {
1944         INIT_LIST_HEAD(&p->list);
1945         p->parent = parent ? parent : &sysctl_table_root.default_set;
1946         p->is_seen = is_seen;
1947 }
1948
1949 #else /* !CONFIG_SYSCTL */
1950 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1951 {
1952         return NULL;
1953 }
1954
1955 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1956                                                     struct ctl_table *table)
1957 {
1958         return NULL;
1959 }
1960
1961 void unregister_sysctl_table(struct ctl_table_header * table)
1962 {
1963 }
1964
1965 void setup_sysctl_set(struct ctl_table_set *p,
1966         struct ctl_table_set *parent,
1967         int (*is_seen)(struct ctl_table_set *))
1968 {
1969 }
1970
1971 void sysctl_head_put(struct ctl_table_header *head)
1972 {
1973 }
1974
1975 #endif /* CONFIG_SYSCTL */
1976
1977 /*
1978  * /proc/sys support
1979  */
1980
1981 #ifdef CONFIG_PROC_SYSCTL
1982
1983 static int _proc_do_string(void* data, int maxlen, int write,
1984                            void __user *buffer,
1985                            size_t *lenp, loff_t *ppos)
1986 {
1987         size_t len;
1988         char __user *p;
1989         char c;
1990
1991         if (!data || !maxlen || !*lenp) {
1992                 *lenp = 0;
1993                 return 0;
1994         }
1995
1996         if (write) {
1997                 len = 0;
1998                 p = buffer;
1999                 while (len < *lenp) {
2000                         if (get_user(c, p++))
2001                                 return -EFAULT;
2002                         if (c == 0 || c == '\n')
2003                                 break;
2004                         len++;
2005                 }
2006                 if (len >= maxlen)
2007                         len = maxlen-1;
2008                 if(copy_from_user(data, buffer, len))
2009                         return -EFAULT;
2010                 ((char *) data)[len] = 0;
2011                 *ppos += *lenp;
2012         } else {
2013                 len = strlen(data);
2014                 if (len > maxlen)
2015                         len = maxlen;
2016
2017                 if (*ppos > len) {
2018                         *lenp = 0;
2019                         return 0;
2020                 }
2021
2022                 data += *ppos;
2023                 len  -= *ppos;
2024
2025                 if (len > *lenp)
2026                         len = *lenp;
2027                 if (len)
2028                         if(copy_to_user(buffer, data, len))
2029                                 return -EFAULT;
2030                 if (len < *lenp) {
2031                         if(put_user('\n', ((char __user *) buffer) + len))
2032                                 return -EFAULT;
2033                         len++;
2034                 }
2035                 *lenp = len;
2036                 *ppos += len;
2037         }
2038         return 0;
2039 }
2040
2041 /**
2042  * proc_dostring - read a string sysctl
2043  * @table: the sysctl table
2044  * @write: %TRUE if this is a write to the sysctl file
2045  * @buffer: the user buffer
2046  * @lenp: the size of the user buffer
2047  * @ppos: file position
2048  *
2049  * Reads/writes a string from/to the user buffer. If the kernel
2050  * buffer provided is not large enough to hold the string, the
2051  * string is truncated. The copied string is %NULL-terminated.
2052  * If the string is being read by the user process, it is copied
2053  * and a newline '\n' is added. It is truncated if the buffer is
2054  * not large enough.
2055  *
2056  * Returns 0 on success.
2057  */
2058 int proc_dostring(struct ctl_table *table, int write,
2059                   void __user *buffer, size_t *lenp, loff_t *ppos)
2060 {
2061         return _proc_do_string(table->data, table->maxlen, write,
2062                                buffer, lenp, ppos);
2063 }
2064
2065
2066 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2067                                  int *valp,
2068                                  int write, void *data)
2069 {
2070         if (write) {
2071                 *valp = *negp ? -*lvalp : *lvalp;
2072         } else {
2073                 int val = *valp;
2074                 if (val < 0) {
2075                         *negp = -1;
2076                         *lvalp = (unsigned long)-val;
2077                 } else {
2078                         *negp = 0;
2079                         *lvalp = (unsigned long)val;
2080                 }
2081         }
2082         return 0;
2083 }
2084
2085 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2086                   int write, void __user *buffer,
2087                   size_t *lenp, loff_t *ppos,
2088                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2089                               int write, void *data),
2090                   void *data)
2091 {
2092 #define TMPBUFLEN 21
2093         int *i, vleft, first = 1, neg;
2094         unsigned long lval;
2095         size_t left, len;
2096
2097         char buf[TMPBUFLEN], *p;
2098         char __user *s = buffer;
2099
2100         if (!tbl_data || !table->maxlen || !*lenp ||
2101             (*ppos && !write)) {
2102                 *lenp = 0;
2103                 return 0;
2104         }
2105
2106         i = (int *) tbl_data;
2107         vleft = table->maxlen / sizeof(*i);
2108         left = *lenp;
2109
2110         if (!conv)
2111                 conv = do_proc_dointvec_conv;
2112
2113         for (; left && vleft--; i++, first=0) {
2114                 if (write) {
2115                         while (left) {
2116                                 char c;
2117                                 if (get_user(c, s))
2118                                         return -EFAULT;
2119                                 if (!isspace(c))
2120                                         break;
2121                                 left--;
2122                                 s++;
2123                         }
2124                         if (!left)
2125                                 break;
2126                         neg = 0;
2127                         len = left;
2128                         if (len > sizeof(buf) - 1)
2129                                 len = sizeof(buf) - 1;
2130                         if (copy_from_user(buf, s, len))
2131                                 return -EFAULT;
2132                         buf[len] = 0;
2133                         p = buf;
2134                         if (*p == '-' && left > 1) {
2135                                 neg = 1;
2136                                 p++;
2137                         }
2138                         if (*p < '0' || *p > '9')
2139                                 break;
2140
2141                         lval = simple_strtoul(p, &p, 0);
2142
2143                         len = p-buf;
2144                         if ((len < left) && *p && !isspace(*p))
2145                                 break;
2146                         s += len;
2147                         left -= len;
2148
2149                         if (conv(&neg, &lval, i, 1, data))
2150                                 break;
2151                 } else {
2152                         p = buf;
2153                         if (!first)
2154                                 *p++ = '\t';
2155
2156                         if (conv(&neg, &lval, i, 0, data))
2157                                 break;
2158
2159                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2160                         len = strlen(buf);
2161                         if (len > left)
2162                                 len = left;
2163                         if(copy_to_user(s, buf, len))
2164                                 return -EFAULT;
2165                         left -= len;
2166                         s += len;
2167                 }
2168         }
2169
2170         if (!write && !first && left) {
2171                 if(put_user('\n', s))
2172                         return -EFAULT;
2173                 left--, s++;
2174         }
2175         if (write) {
2176                 while (left) {
2177                         char c;
2178                         if (get_user(c, s++))
2179                                 return -EFAULT;
2180                         if (!isspace(c))
2181                                 break;
2182                         left--;
2183                 }
2184         }
2185         if (write && first)
2186                 return -EINVAL;
2187         *lenp -= left;
2188         *ppos += *lenp;
2189         return 0;
2190 #undef TMPBUFLEN
2191 }
2192
2193 static int do_proc_dointvec(struct ctl_table *table, int write,
2194                   void __user *buffer, size_t *lenp, loff_t *ppos,
2195                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2196                               int write, void *data),
2197                   void *data)
2198 {
2199         return __do_proc_dointvec(table->data, table, write,
2200                         buffer, lenp, ppos, conv, data);
2201 }
2202
2203 /**
2204  * proc_dointvec - read a vector of integers
2205  * @table: the sysctl table
2206  * @write: %TRUE if this is a write to the sysctl file
2207  * @buffer: the user buffer
2208  * @lenp: the size of the user buffer
2209  * @ppos: file position
2210  *
2211  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2212  * values from/to the user buffer, treated as an ASCII string.
2213  *
2214  * Returns 0 on success.
2215  */
2216 int proc_dointvec(struct ctl_table *table, int write,
2217                      void __user *buffer, size_t *lenp, loff_t *ppos)
2218 {
2219     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2220                             NULL,NULL);
2221 }
2222
2223 /*
2224  * Taint values can only be increased
2225  * This means we can safely use a temporary.
2226  */
2227 static int proc_taint(struct ctl_table *table, int write,
2228                                void __user *buffer, size_t *lenp, loff_t *ppos)
2229 {
2230         struct ctl_table t;
2231         unsigned long tmptaint = get_taint();
2232         int err;
2233
2234         if (write && !capable(CAP_SYS_ADMIN))
2235                 return -EPERM;
2236
2237         t = *table;
2238         t.data = &tmptaint;
2239         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2240         if (err < 0)
2241                 return err;
2242
2243         if (write) {
2244                 /*
2245                  * Poor man's atomic or. Not worth adding a primitive
2246                  * to everyone's atomic.h for this
2247                  */
2248                 int i;
2249                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2250                         if ((tmptaint >> i) & 1)
2251                                 add_taint(i);
2252                 }
2253         }
2254
2255         return err;
2256 }
2257
2258 struct do_proc_dointvec_minmax_conv_param {
2259         int *min;
2260         int *max;
2261 };
2262
2263 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2264                                         int *valp,
2265                                         int write, void *data)
2266 {
2267         struct do_proc_dointvec_minmax_conv_param *param = data;
2268         if (write) {
2269                 int val = *negp ? -*lvalp : *lvalp;
2270                 if ((param->min && *param->min > val) ||
2271                     (param->max && *param->max < val))
2272                         return -EINVAL;
2273                 *valp = val;
2274         } else {
2275                 int val = *valp;
2276                 if (val < 0) {
2277                         *negp = -1;
2278                         *lvalp = (unsigned long)-val;
2279                 } else {
2280                         *negp = 0;
2281                         *lvalp = (unsigned long)val;
2282                 }
2283         }
2284         return 0;
2285 }
2286
2287 /**
2288  * proc_dointvec_minmax - read a vector of integers with min/max values
2289  * @table: the sysctl table
2290  * @write: %TRUE if this is a write to the sysctl file
2291  * @buffer: the user buffer
2292  * @lenp: the size of the user buffer
2293  * @ppos: file position
2294  *
2295  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2296  * values from/to the user buffer, treated as an ASCII string.
2297  *
2298  * This routine will ensure the values are within the range specified by
2299  * table->extra1 (min) and table->extra2 (max).
2300  *
2301  * Returns 0 on success.
2302  */
2303 int proc_dointvec_minmax(struct ctl_table *table, int write,
2304                   void __user *buffer, size_t *lenp, loff_t *ppos)
2305 {
2306         struct do_proc_dointvec_minmax_conv_param param = {
2307                 .min = (int *) table->extra1,
2308                 .max = (int *) table->extra2,
2309         };
2310         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2311                                 do_proc_dointvec_minmax_conv, &param);
2312 }
2313
2314 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2315                                      void __user *buffer,
2316                                      size_t *lenp, loff_t *ppos,
2317                                      unsigned long convmul,
2318                                      unsigned long convdiv)
2319 {
2320 #define TMPBUFLEN 21
2321         unsigned long *i, *min, *max, val;
2322         int vleft, first=1, neg;
2323         size_t len, left;
2324         char buf[TMPBUFLEN], *p;
2325         char __user *s = buffer;
2326
2327         if (!data || !table->maxlen || !*lenp ||
2328             (*ppos && !write)) {
2329                 *lenp = 0;
2330                 return 0;
2331         }
2332
2333         i = (unsigned long *) data;
2334         min = (unsigned long *) table->extra1;
2335         max = (unsigned long *) table->extra2;
2336         vleft = table->maxlen / sizeof(unsigned long);
2337         left = *lenp;
2338
2339         for (; left && vleft--; i++, min++, max++, first=0) {
2340                 if (write) {
2341                         while (left) {
2342                                 char c;
2343                                 if (get_user(c, s))
2344                                         return -EFAULT;
2345                                 if (!isspace(c))
2346                                         break;
2347                                 left--;
2348                                 s++;
2349                         }
2350                         if (!left)
2351                                 break;
2352                         neg = 0;
2353                         len = left;
2354                         if (len > TMPBUFLEN-1)
2355                                 len = TMPBUFLEN-1;
2356                         if (copy_from_user(buf, s, len))
2357                                 return -EFAULT;
2358                         buf[len] = 0;
2359                         p = buf;
2360                         if (*p == '-' && left > 1) {
2361                                 neg = 1;
2362                                 p++;
2363                         }
2364                         if (*p < '0' || *p > '9')
2365                                 break;
2366                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2367                         len = p-buf;
2368                         if ((len < left) && *p && !isspace(*p))
2369                                 break;
2370                         if (neg)
2371                                 val = -val;
2372                         s += len;
2373                         left -= len;
2374
2375                         if(neg)
2376                                 continue;
2377                         if ((min && val < *min) || (max && val > *max))
2378                                 continue;
2379                         *i = val;
2380                 } else {
2381                         p = buf;
2382                         if (!first)
2383                                 *p++ = '\t';
2384                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2385                         len = strlen(buf);
2386                         if (len > left)
2387                                 len = left;
2388                         if(copy_to_user(s, buf, len))
2389                                 return -EFAULT;
2390                         left -= len;
2391                         s += len;
2392                 }
2393         }
2394
2395         if (!write && !first && left) {
2396                 if(put_user('\n', s))
2397                         return -EFAULT;
2398                 left--, s++;
2399         }
2400         if (write) {
2401                 while (left) {
2402                         char c;
2403                         if (get_user(c, s++))
2404                                 return -EFAULT;
2405                         if (!isspace(c))
2406                                 break;
2407                         left--;
2408                 }
2409         }
2410         if (write && first)
2411                 return -EINVAL;
2412         *lenp -= left;
2413         *ppos += *lenp;
2414         return 0;
2415 #undef TMPBUFLEN
2416 }
2417
2418 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2419                                      void __user *buffer,
2420                                      size_t *lenp, loff_t *ppos,
2421                                      unsigned long convmul,
2422                                      unsigned long convdiv)
2423 {
2424         return __do_proc_doulongvec_minmax(table->data, table, write,
2425                         buffer, lenp, ppos, convmul, convdiv);
2426 }
2427
2428 /**
2429  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2430  * @table: the sysctl table
2431  * @write: %TRUE if this is a write to the sysctl file
2432  * @buffer: the user buffer
2433  * @lenp: the size of the user buffer
2434  * @ppos: file position
2435  *
2436  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2437  * values from/to the user buffer, treated as an ASCII string.
2438  *
2439  * This routine will ensure the values are within the range specified by
2440  * table->extra1 (min) and table->extra2 (max).
2441  *
2442  * Returns 0 on success.
2443  */
2444 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2445                            void __user *buffer, size_t *lenp, loff_t *ppos)
2446 {
2447     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2448 }
2449
2450 /**
2451  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2452  * @table: the sysctl table
2453  * @write: %TRUE if this is a write to the sysctl file
2454  * @buffer: the user buffer
2455  * @lenp: the size of the user buffer
2456  * @ppos: file position
2457  *
2458  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2459  * values from/to the user buffer, treated as an ASCII string. The values
2460  * are treated as milliseconds, and converted to jiffies when they are stored.
2461  *
2462  * This routine will ensure the values are within the range specified by
2463  * table->extra1 (min) and table->extra2 (max).
2464  *
2465  * Returns 0 on success.
2466  */
2467 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2468                                       void __user *buffer,
2469                                       size_t *lenp, loff_t *ppos)
2470 {
2471     return do_proc_doulongvec_minmax(table, write, buffer,
2472                                      lenp, ppos, HZ, 1000l);
2473 }
2474
2475
2476 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2477                                          int *valp,
2478                                          int write, void *data)
2479 {
2480         if (write) {
2481                 if (*lvalp > LONG_MAX / HZ)
2482                         return 1;
2483                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2484         } else {
2485                 int val = *valp;
2486                 unsigned long lval;
2487                 if (val < 0) {
2488                         *negp = -1;
2489                         lval = (unsigned long)-val;
2490                 } else {
2491                         *negp = 0;
2492                         lval = (unsigned long)val;
2493                 }
2494                 *lvalp = lval / HZ;
2495         }
2496         return 0;
2497 }
2498
2499 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2500                                                 int *valp,
2501                                                 int write, void *data)
2502 {
2503         if (write) {
2504                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2505                         return 1;
2506                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2507         } else {
2508                 int val = *valp;
2509                 unsigned long lval;
2510                 if (val < 0) {
2511                         *negp = -1;
2512                         lval = (unsigned long)-val;
2513                 } else {
2514                         *negp = 0;
2515                         lval = (unsigned long)val;
2516                 }
2517                 *lvalp = jiffies_to_clock_t(lval);
2518         }
2519         return 0;
2520 }
2521
2522 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2523                                             int *valp,
2524                                             int write, void *data)
2525 {
2526         if (write) {
2527                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2528         } else {
2529                 int val = *valp;
2530                 unsigned long lval;
2531                 if (val < 0) {
2532                         *negp = -1;
2533                         lval = (unsigned long)-val;
2534                 } else {
2535                         *negp = 0;
2536                         lval = (unsigned long)val;
2537                 }
2538                 *lvalp = jiffies_to_msecs(lval);
2539         }
2540         return 0;
2541 }
2542
2543 /**
2544  * proc_dointvec_jiffies - read a vector of integers as seconds
2545  * @table: the sysctl table
2546  * @write: %TRUE if this is a write to the sysctl file
2547  * @buffer: the user buffer
2548  * @lenp: the size of the user buffer
2549  * @ppos: file position
2550  *
2551  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2552  * values from/to the user buffer, treated as an ASCII string.
2553  * The values read are assumed to be in seconds, and are converted into
2554  * jiffies.
2555  *
2556  * Returns 0 on success.
2557  */
2558 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2559                           void __user *buffer, size_t *lenp, loff_t *ppos)
2560 {
2561     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2562                             do_proc_dointvec_jiffies_conv,NULL);
2563 }
2564
2565 /**
2566  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2567  * @table: the sysctl table
2568  * @write: %TRUE if this is a write to the sysctl file
2569  * @buffer: the user buffer
2570  * @lenp: the size of the user buffer
2571  * @ppos: pointer to the file position
2572  *
2573  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2574  * values from/to the user buffer, treated as an ASCII string.
2575  * The values read are assumed to be in 1/USER_HZ seconds, and
2576  * are converted into jiffies.
2577  *
2578  * Returns 0 on success.
2579  */
2580 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2581                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2582 {
2583     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2584                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2585 }
2586
2587 /**
2588  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2589  * @table: the sysctl table
2590  * @write: %TRUE if this is a write to the sysctl file
2591  * @buffer: the user buffer
2592  * @lenp: the size of the user buffer
2593  * @ppos: file position
2594  * @ppos: the current position in the file
2595  *
2596  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2597  * values from/to the user buffer, treated as an ASCII string.
2598  * The values read are assumed to be in 1/1000 seconds, and
2599  * are converted into jiffies.
2600  *
2601  * Returns 0 on success.
2602  */
2603 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2604                              void __user *buffer, size_t *lenp, loff_t *ppos)
2605 {
2606         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2607                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2608 }
2609
2610 static int proc_do_cad_pid(struct ctl_table *table, int write,
2611                            void __user *buffer, size_t *lenp, loff_t *ppos)
2612 {
2613         struct pid *new_pid;
2614         pid_t tmp;
2615         int r;
2616
2617         tmp = pid_vnr(cad_pid);
2618
2619         r = __do_proc_dointvec(&tmp, table, write, buffer,
2620                                lenp, ppos, NULL, NULL);
2621         if (r || !write)
2622                 return r;
2623
2624         new_pid = find_get_pid(tmp);
2625         if (!new_pid)
2626                 return -ESRCH;
2627
2628         put_pid(xchg(&cad_pid, new_pid));
2629         return 0;
2630 }
2631
2632 #else /* CONFIG_PROC_FS */
2633
2634 int proc_dostring(struct ctl_table *table, int write,
2635                   void __user *buffer, size_t *lenp, loff_t *ppos)
2636 {
2637         return -ENOSYS;
2638 }
2639
2640 int proc_dointvec(struct ctl_table *table, int write,
2641                   void __user *buffer, size_t *lenp, loff_t *ppos)
2642 {
2643         return -ENOSYS;
2644 }
2645
2646 int proc_dointvec_minmax(struct ctl_table *table, int write,
2647                     void __user *buffer, size_t *lenp, loff_t *ppos)
2648 {
2649         return -ENOSYS;
2650 }
2651
2652 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2653                     void __user *buffer, size_t *lenp, loff_t *ppos)
2654 {
2655         return -ENOSYS;
2656 }
2657
2658 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2659                     void __user *buffer, size_t *lenp, loff_t *ppos)
2660 {
2661         return -ENOSYS;
2662 }
2663
2664 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2665                              void __user *buffer, size_t *lenp, loff_t *ppos)
2666 {
2667         return -ENOSYS;
2668 }
2669
2670 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2671                     void __user *buffer, size_t *lenp, loff_t *ppos)
2672 {
2673         return -ENOSYS;
2674 }
2675
2676 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2677                                       void __user *buffer,
2678                                       size_t *lenp, loff_t *ppos)
2679 {
2680     return -ENOSYS;
2681 }
2682
2683
2684 #endif /* CONFIG_PROC_FS */
2685
2686 /*
2687  * No sense putting this after each symbol definition, twice,
2688  * exception granted :-)
2689  */
2690 EXPORT_SYMBOL(proc_dointvec);
2691 EXPORT_SYMBOL(proc_dointvec_jiffies);
2692 EXPORT_SYMBOL(proc_dointvec_minmax);
2693 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2694 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2695 EXPORT_SYMBOL(proc_dostring);
2696 EXPORT_SYMBOL(proc_doulongvec_minmax);
2697 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2698 EXPORT_SYMBOL(register_sysctl_table);
2699 EXPORT_SYMBOL(register_sysctl_paths);
2700 EXPORT_SYMBOL(unregister_sysctl_table);