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/printk.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/security.h>
  30 #include <linux/ctype.h>
  31 #include <linux/kmemcheck.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/ratelimit.h>
  41 #include <linux/compaction.h>
  42 #include <linux/hugetlb.h>
  43 #include <linux/initrd.h>
  44 #include <linux/key.h>
  45 #include <linux/times.h>
  46 #include <linux/limits.h>
  47 #include <linux/dcache.h>
  48 #include <linux/dnotify.h>
  49 #include <linux/syscalls.h>
  50 #include <linux/vmstat.h>
  51 #include <linux/nfs_fs.h>
  52 #include <linux/acpi.h>
  53 #include <linux/reboot.h>
  54 #include <linux/ftrace.h>
  55 #include <linux/perf_event.h>
  56 #include <linux/kprobes.h>
  57 #include <linux/pipe_fs_i.h>
  58 #include <linux/oom.h>
  59 #include <linux/kmod.h>
  60
  61 #include <asm/uaccess.h>
  62 #include <asm/processor.h>
  63
  64 #ifdef CONFIG_X86
  65 #include <asm/nmi.h>
  66 #include <asm/stacktrace.h>
  67 #include <asm/io.h>
  68 #endif
  69 #ifdef CONFIG_BSD_PROCESS_ACCT
  70 #include <linux/acct.h>
  71 #endif
  72 #ifdef CONFIG_RT_MUTEXES
  73 #include <linux/rtmutex.h>
  74 #endif
  75 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  76 #include <linux/lockdep.h>
  77 #endif
  78 #ifdef CONFIG_CHR_DEV_SG
  79 #include <scsi/sg.h>
  80 #endif
  81
  82 #ifdef CONFIG_LOCKUP_DETECTOR
  83 #include <linux/nmi.h>
  84 #endif
  85
  86
  87 #if defined(CONFIG_SYSCTL)
  88
  89 /* External variables not in a header file. */
  90 extern int sysctl_overcommit_memory;
  91 extern int sysctl_overcommit_ratio;
  92 extern int max_threads;
  93 extern int core_uses_pid;
  94 extern int suid_dumpable;
  95 extern char core_pattern[];
  96 extern unsigned int core_pipe_limit;
  97 extern int pid_max;
  98 extern int min_free_kbytes;
  99 extern int min_free_order_shift;
 100 extern int pid_max_min, pid_max_max;
 101 extern int sysctl_drop_caches;
 102 extern int percpu_pagelist_fraction;
 103 extern int compat_log;
 104 extern int latencytop_enabled;
 105 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 106 #ifndef CONFIG_MMU
 107 extern int sysctl_nr_trim_pages;
 108 #endif
 109 #ifdef CONFIG_BLOCK
 110 extern int blk_iopoll_enabled;
 111 #endif
 112
 113 /* Constants used for minimum and  maximum */
 114 #ifdef CONFIG_LOCKUP_DETECTOR
 115 static int sixty = 60;
 116 static int neg_one = -1;
 117 #endif
 118
 119 static int zero;
 120 static int __maybe_unused one = 1;
 121 static int __maybe_unused two = 2;
 122 static int __maybe_unused three = 3;
 123 static unsigned long one_ul = 1;
 124 static int one_hundred = 100;
 125 #ifdef CONFIG_PRINTK
 126 static int ten_thousand = 10000;
 127 #endif
 128
 129 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 130 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 131
 132 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 133 static int maxolduid = 65535;
 134 static int minolduid;
 135 static int min_percpu_pagelist_fract = 8;
 136
 137 static int ngroups_max = NGROUPS_MAX;
 138
 139 #ifdef CONFIG_INOTIFY_USER
 140 #include <linux/inotify.h>
 141 #endif
 142 #ifdef CONFIG_SPARC
 143 #include <asm/system.h>
 144 #endif
 145
 146 #ifdef CONFIG_SPARC64
 147 extern int sysctl_tsb_ratio;
 148 #endif
 149
 150 #ifdef __hppa__
 151 extern int pwrsw_enabled;
 152 extern int unaligned_enabled;
 153 #endif
 154
 155 #ifdef CONFIG_S390
 156 #ifdef CONFIG_MATHEMU
 157 extern int sysctl_ieee_emulation_warnings;
 158 #endif
 159 extern int sysctl_userprocess_debug;
 160 extern int spin_retry;
 161 #endif
 162
 163 #ifdef CONFIG_IA64
 164 extern int no_unaligned_warning;
 165 extern int unaligned_dump_stack;
 166 #endif
 167
 168 #ifdef CONFIG_PROC_SYSCTL
 169 static int proc_do_cad_pid(struct ctl_table *table, int write,
 170                   void __user *buffer, size_t *lenp, loff_t *ppos);
 171 static int proc_taint(struct ctl_table *table, int write,
 172                                void __user *buffer, size_t *lenp, loff_t *ppos);
 173 #endif
 174
 175 #ifdef CONFIG_PRINTK
 176 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
 177                                 void __user *buffer, size_t *lenp, loff_t *ppos);
 178 #endif
 179
 180 #ifdef CONFIG_MAGIC_SYSRQ
 181 /* Note: sysrq code uses it's own private copy */
 182 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
 183
 184 static int sysrq_sysctl_handler(ctl_table *table, int write,
 185                                 void __user *buffer, size_t *lenp,
 186                                 loff_t *ppos)
 187 {
 188         int error;
 189
 190         error = proc_dointvec(table, write, buffer, lenp, ppos);
 191         if (error)
 192                 return error;
 193
 194         if (write)
 195                 sysrq_toggle_support(__sysrq_enabled);
 196
 197         return 0;
 198 }
 199
 200 #endif
 201
 202 static struct ctl_table root_table[];
 203 static struct ctl_table_root sysctl_table_root;
 204 static struct ctl_table_header root_table_header = {
 205         {{.count = 1,
 206         .ctl_table = root_table,
 207         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
 208         .root = &sysctl_table_root,
 209         .set = &sysctl_table_root.default_set,
 210 };
 211 static struct ctl_table_root sysctl_table_root = {
 212         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 213         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 214 };
 215
 216 static struct ctl_table kern_table[];
 217 static struct ctl_table vm_table[];
 218 static struct ctl_table fs_table[];
 219 static struct ctl_table debug_table[];
 220 static struct ctl_table dev_table[];
 221 extern struct ctl_table random_table[];
 222 #ifdef CONFIG_EPOLL
 223 extern struct ctl_table epoll_table[];
 224 #endif
 225
 226 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 227 int sysctl_legacy_va_layout;
 228 #endif
 229
 230 /* The default sysctl tables: */
 231
 232 static struct ctl_table root_table[] = {
 233         {
 234                 .procname       = "kernel",
 235                 .mode           = 0555,
 236                 .child          = kern_table,
 237         },
 238         {
 239                 .procname       = "vm",
 240                 .mode           = 0555,
 241                 .child          = vm_table,
 242         },
 243         {
 244                 .procname       = "fs",
 245                 .mode           = 0555,
 246                 .child          = fs_table,
 247         },
 248         {
 249                 .procname       = "debug",
 250                 .mode           = 0555,
 251                 .child          = debug_table,
 252         },
 253         {
 254                 .procname       = "dev",
 255                 .mode           = 0555,
 256                 .child          = dev_table,
 257         },
 258         { }
 259 };
 260
 261 #ifdef CONFIG_SCHED_DEBUG
 262 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 263 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 264 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 265 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 266 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 267 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 268 #endif
 269
 270 #ifdef CONFIG_COMPACTION
 271 static int min_extfrag_threshold;
 272 static int max_extfrag_threshold = 1000;
 273 #endif
 274
 275 static struct ctl_table kern_table[] = {
 276         {
 277                 .procname       = "sched_child_runs_first",
 278                 .data           = &sysctl_sched_child_runs_first,
 279                 .maxlen         = sizeof(unsigned int),
 280                 .mode           = 0644,
 281                 .proc_handler   = proc_dointvec,
 282         },
 283 #ifdef CONFIG_SCHED_DEBUG
 284         {
 285                 .procname       = "sched_min_granularity_ns",
 286                 .data           = &sysctl_sched_min_granularity,
 287                 .maxlen         = sizeof(unsigned int),
 288                 .mode           = 0644,
 289                 .proc_handler   = sched_proc_update_handler,
 290                 .extra1         = &min_sched_granularity_ns,
 291                 .extra2         = &max_sched_granularity_ns,
 292         },
 293         {
 294                 .procname       = "sched_latency_ns",
 295                 .data           = &sysctl_sched_latency,
 296                 .maxlen         = sizeof(unsigned int),
 297                 .mode           = 0644,
 298                 .proc_handler   = sched_proc_update_handler,
 299                 .extra1         = &min_sched_granularity_ns,
 300                 .extra2         = &max_sched_granularity_ns,
 301         },
 302         {
 303                 .procname       = "sched_wakeup_granularity_ns",
 304                 .data           = &sysctl_sched_wakeup_granularity,
 305                 .maxlen         = sizeof(unsigned int),
 306                 .mode           = 0644,
 307                 .proc_handler   = sched_proc_update_handler,
 308                 .extra1         = &min_wakeup_granularity_ns,
 309                 .extra2         = &max_wakeup_granularity_ns,
 310         },
 311         {
 312                 .procname       = "sched_tunable_scaling",
 313                 .data           = &sysctl_sched_tunable_scaling,
 314                 .maxlen         = sizeof(enum sched_tunable_scaling),
 315                 .mode           = 0644,
 316                 .proc_handler   = sched_proc_update_handler,
 317                 .extra1         = &min_sched_tunable_scaling,
 318                 .extra2         = &max_sched_tunable_scaling,
 319         },
 320         {
 321                 .procname       = "sched_migration_cost",
 322                 .data           = &sysctl_sched_migration_cost,
 323                 .maxlen         = sizeof(unsigned int),
 324                 .mode           = 0644,
 325                 .proc_handler   = proc_dointvec,
 326         },
 327         {
 328                 .procname       = "sched_nr_migrate",
 329                 .data           = &sysctl_sched_nr_migrate,
 330                 .maxlen         = sizeof(unsigned int),
 331                 .mode           = 0644,
 332                 .proc_handler   = proc_dointvec,
 333         },
 334         {
 335                 .procname       = "sched_time_avg",
 336                 .data           = &sysctl_sched_time_avg,
 337                 .maxlen         = sizeof(unsigned int),
 338                 .mode           = 0644,
 339                 .proc_handler   = proc_dointvec,
 340         },
 341         {
 342                 .procname       = "sched_shares_window",
 343                 .data           = &sysctl_sched_shares_window,
 344                 .maxlen         = sizeof(unsigned int),
 345                 .mode           = 0644,
 346                 .proc_handler   = proc_dointvec,
 347         },
 348         {
 349                 .procname       = "timer_migration",
 350                 .data           = &sysctl_timer_migration,
 351                 .maxlen         = sizeof(unsigned int),
 352                 .mode           = 0644,
 353                 .proc_handler   = proc_dointvec_minmax,
 354                 .extra1         = &zero,
 355                 .extra2         = &one,
 356         },
 357 #endif
 358         {
 359                 .procname       = "sched_rt_period_us",
 360                 .data           = &sysctl_sched_rt_period,
 361                 .maxlen         = sizeof(unsigned int),
 362                 .mode           = 0644,
 363                 .proc_handler   = sched_rt_handler,
 364         },
 365         {
 366                 .procname       = "sched_rt_runtime_us",
 367                 .data           = &sysctl_sched_rt_runtime,
 368                 .maxlen         = sizeof(int),
 369                 .mode           = 0644,
 370                 .proc_handler   = sched_rt_handler,
 371         },
 372 #ifdef CONFIG_SCHED_AUTOGROUP
 373         {
 374                 .procname       = "sched_autogroup_enabled",
 375                 .data           = &sysctl_sched_autogroup_enabled,
 376                 .maxlen         = sizeof(unsigned int),
 377                 .mode           = 0644,
 378                 .proc_handler   = proc_dointvec_minmax,
 379                 .extra1         = &zero,
 380                 .extra2         = &one,
 381         },
 382 #endif
 383 #ifdef CONFIG_PROVE_LOCKING
 384         {
 385                 .procname       = "prove_locking",
 386                 .data           = &prove_locking,
 387                 .maxlen         = sizeof(int),
 388                 .mode           = 0644,
 389                 .proc_handler   = proc_dointvec,
 390         },
 391 #endif
 392 #ifdef CONFIG_LOCK_STAT
 393         {
 394                 .procname       = "lock_stat",
 395                 .data           = &lock_stat,
 396                 .maxlen         = sizeof(int),
 397                 .mode           = 0644,
 398                 .proc_handler   = proc_dointvec,
 399         },
 400 #endif
 401         {
 402                 .procname       = "panic",
 403                 .data           = &panic_timeout,
 404                 .maxlen         = sizeof(int),
 405                 .mode           = 0644,
 406                 .proc_handler   = proc_dointvec,
 407         },
 408         {
 409                 .procname       = "core_uses_pid",
 410                 .data           = &core_uses_pid,
 411                 .maxlen         = sizeof(int),
 412                 .mode           = 0644,
 413                 .proc_handler   = proc_dointvec,
 414         },
 415         {
 416                 .procname       = "core_pattern",
 417                 .data           = core_pattern,
 418                 .maxlen         = CORENAME_MAX_SIZE,
 419                 .mode           = 0644,
 420                 .proc_handler   = proc_dostring,
 421         },
 422         {
 423                 .procname       = "core_pipe_limit",
 424                 .data           = &core_pipe_limit,
 425                 .maxlen         = sizeof(unsigned int),
 426                 .mode           = 0644,
 427                 .proc_handler   = proc_dointvec,
 428         },
 429 #ifdef CONFIG_PROC_SYSCTL
 430         {
 431                 .procname       = "tainted",
 432                 .maxlen         = sizeof(long),
 433                 .mode           = 0644,
 434                 .proc_handler   = proc_taint,
 435         },
 436 #endif
 437 #ifdef CONFIG_LATENCYTOP
 438         {
 439                 .procname       = "latencytop",
 440                 .data           = &latencytop_enabled,
 441                 .maxlen         = sizeof(int),
 442                 .mode           = 0644,
 443                 .proc_handler   = proc_dointvec,
 444         },
 445 #endif
 446 #ifdef CONFIG_BLK_DEV_INITRD
 447         {
 448                 .procname       = "real-root-dev",
 449                 .data           = &real_root_dev,
 450                 .maxlen         = sizeof(int),
 451                 .mode           = 0644,
 452                 .proc_handler   = proc_dointvec,
 453         },
 454 #endif
 455         {
 456                 .procname       = "print-fatal-signals",
 457                 .data           = &print_fatal_signals,
 458                 .maxlen         = sizeof(int),
 459                 .mode           = 0644,
 460                 .proc_handler   = proc_dointvec,
 461         },
 462 #ifdef CONFIG_SPARC
 463         {
 464                 .procname       = "reboot-cmd",
 465                 .data           = reboot_command,
 466                 .maxlen         = 256,
 467                 .mode           = 0644,
 468                 .proc_handler   = proc_dostring,
 469         },
 470         {
 471                 .procname       = "stop-a",
 472                 .data           = &stop_a_enabled,
 473                 .maxlen         = sizeof (int),
 474                 .mode           = 0644,
 475                 .proc_handler   = proc_dointvec,
 476         },
 477         {
 478                 .procname       = "scons-poweroff",
 479                 .data           = &scons_pwroff,
 480                 .maxlen         = sizeof (int),
 481                 .mode           = 0644,
 482                 .proc_handler   = proc_dointvec,
 483         },
 484 #endif
 485 #ifdef CONFIG_SPARC64
 486         {
 487                 .procname       = "tsb-ratio",
 488                 .data           = &sysctl_tsb_ratio,
 489                 .maxlen         = sizeof (int),
 490                 .mode           = 0644,
 491                 .proc_handler   = proc_dointvec,
 492         },
 493 #endif
 494 #ifdef __hppa__
 495         {
 496                 .procname       = "soft-power",
 497                 .data           = &pwrsw_enabled,
 498                 .maxlen         = sizeof (int),
 499                 .mode           = 0644,
 500                 .proc_handler   = proc_dointvec,
 501         },
 502         {
 503                 .procname       = "unaligned-trap",
 504                 .data           = &unaligned_enabled,
 505                 .maxlen         = sizeof (int),
 506                 .mode           = 0644,
 507                 .proc_handler   = proc_dointvec,
 508         },
 509 #endif
 510         {
 511                 .procname       = "ctrl-alt-del",
 512                 .data           = &C_A_D,
 513                 .maxlen         = sizeof(int),
 514                 .mode           = 0644,
 515                 .proc_handler   = proc_dointvec,
 516         },
 517 #ifdef CONFIG_FUNCTION_TRACER
 518         {
 519                 .procname       = "ftrace_enabled",
 520                 .data           = &ftrace_enabled,
 521                 .maxlen         = sizeof(int),
 522                 .mode           = 0644,
 523                 .proc_handler   = ftrace_enable_sysctl,
 524         },
 525 #endif
 526 #ifdef CONFIG_STACK_TRACER
 527         {
 528                 .procname       = "stack_tracer_enabled",
 529                 .data           = &stack_tracer_enabled,
 530                 .maxlen         = sizeof(int),
 531                 .mode           = 0644,
 532                 .proc_handler   = stack_trace_sysctl,
 533         },
 534 #endif
 535 #ifdef CONFIG_TRACING
 536         {
 537                 .procname       = "ftrace_dump_on_oops",
 538                 .data           = &ftrace_dump_on_oops,
 539                 .maxlen         = sizeof(int),
 540                 .mode           = 0644,
 541                 .proc_handler   = proc_dointvec,
 542         },
 543 #endif
 544 #ifdef CONFIG_MODULES
 545         {
 546                 .procname       = "modprobe",
 547                 .data           = &modprobe_path,
 548                 .maxlen         = KMOD_PATH_LEN,
 549                 .mode           = 0644,
 550                 .proc_handler   = proc_dostring,
 551         },
 552         {
 553                 .procname       = "modules_disabled",
 554                 .data           = &modules_disabled,
 555                 .maxlen         = sizeof(int),
 556                 .mode           = 0644,
 557                 /* only handle a transition from default "0" to "1" */
 558                 .proc_handler   = proc_dointvec_minmax,
 559                 .extra1         = &one,
 560                 .extra2         = &one,
 561         },
 562 #endif
 563 #ifdef CONFIG_HOTPLUG
 564         {
 565                 .procname       = "hotplug",
 566                 .data           = &uevent_helper,
 567                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 568                 .mode           = 0644,
 569                 .proc_handler   = proc_dostring,
 570         },
 571 #endif
 572 #ifdef CONFIG_CHR_DEV_SG
 573         {
 574                 .procname       = "sg-big-buff",
 575                 .data           = &sg_big_buff,
 576                 .maxlen         = sizeof (int),
 577                 .mode           = 0444,
 578                 .proc_handler   = proc_dointvec,
 579         },
 580 #endif
 581 #ifdef CONFIG_BSD_PROCESS_ACCT
 582         {
 583                 .procname       = "acct",
 584                 .data           = &acct_parm,
 585                 .maxlen         = 3*sizeof(int),
 586                 .mode           = 0644,
 587                 .proc_handler   = proc_dointvec,
 588         },
 589 #endif
 590 #ifdef CONFIG_MAGIC_SYSRQ
 591         {
 592                 .procname       = "sysrq",
 593                 .data           = &__sysrq_enabled,
 594                 .maxlen         = sizeof (int),
 595                 .mode           = 0644,
 596                 .proc_handler   = sysrq_sysctl_handler,
 597         },
 598 #endif
 599 #ifdef CONFIG_PROC_SYSCTL
 600         {
 601                 .procname       = "cad_pid",
 602                 .data           = NULL,
 603                 .maxlen         = sizeof (int),
 604                 .mode           = 0600,
 605                 .proc_handler   = proc_do_cad_pid,
 606         },
 607 #endif
 608         {
 609                 .procname       = "threads-max",
 610                 .data           = &max_threads,
 611                 .maxlen         = sizeof(int),
 612                 .mode           = 0644,
 613                 .proc_handler   = proc_dointvec,
 614         },
 615         {
 616                 .procname       = "random",
 617                 .mode           = 0555,
 618                 .child          = random_table,
 619         },
 620         {
 621                 .procname       = "usermodehelper",
 622                 .mode           = 0555,
 623                 .child          = usermodehelper_table,
 624         },
 625         {
 626                 .procname       = "overflowuid",
 627                 .data           = &overflowuid,
 628                 .maxlen         = sizeof(int),
 629                 .mode           = 0644,
 630                 .proc_handler   = proc_dointvec_minmax,
 631                 .extra1         = &minolduid,
 632                 .extra2         = &maxolduid,
 633         },
 634         {
 635                 .procname       = "overflowgid",
 636                 .data           = &overflowgid,
 637                 .maxlen         = sizeof(int),
 638                 .mode           = 0644,
 639                 .proc_handler   = proc_dointvec_minmax,
 640                 .extra1         = &minolduid,
 641                 .extra2         = &maxolduid,
 642         },
 643 #ifdef CONFIG_S390
 644 #ifdef CONFIG_MATHEMU
 645         {
 646                 .procname       = "ieee_emulation_warnings",
 647                 .data           = &sysctl_ieee_emulation_warnings,
 648                 .maxlen         = sizeof(int),
 649                 .mode           = 0644,
 650                 .proc_handler   = proc_dointvec,
 651         },
 652 #endif
 653         {
 654                 .procname       = "userprocess_debug",
 655                 .data           = &show_unhandled_signals,
 656                 .maxlen         = sizeof(int),
 657                 .mode           = 0644,
 658                 .proc_handler   = proc_dointvec,
 659         },
 660 #endif
 661         {
 662                 .procname       = "pid_max",
 663                 .data           = &pid_max,
 664                 .maxlen         = sizeof (int),
 665                 .mode           = 0644,
 666                 .proc_handler   = proc_dointvec_minmax,
 667                 .extra1         = &pid_max_min,
 668                 .extra2         = &pid_max_max,
 669         },
 670         {
 671                 .procname       = "panic_on_oops",
 672                 .data           = &panic_on_oops,
 673                 .maxlen         = sizeof(int),
 674                 .mode           = 0644,
 675                 .proc_handler   = proc_dointvec,
 676         },
 677 #if defined CONFIG_PRINTK
 678         {
 679                 .procname       = "printk",
 680                 .data           = &console_loglevel,
 681                 .maxlen         = 4*sizeof(int),
 682                 .mode           = 0644,
 683                 .proc_handler   = proc_dointvec,
 684         },
 685         {
 686                 .procname       = "printk_ratelimit",
 687                 .data           = &printk_ratelimit_state.interval,
 688                 .maxlen         = sizeof(int),
 689                 .mode           = 0644,
 690                 .proc_handler   = proc_dointvec_jiffies,
 691         },
 692         {
 693                 .procname       = "printk_ratelimit_burst",
 694                 .data           = &printk_ratelimit_state.burst,
 695                 .maxlen         = sizeof(int),
 696                 .mode           = 0644,
 697                 .proc_handler   = proc_dointvec,
 698         },
 699         {
 700                 .procname       = "printk_delay",
 701                 .data           = &printk_delay_msec,
 702                 .maxlen         = sizeof(int),
 703                 .mode           = 0644,
 704                 .proc_handler   = proc_dointvec_minmax,
 705                 .extra1         = &zero,
 706                 .extra2         = &ten_thousand,
 707         },
 708         {
 709                 .procname       = "dmesg_restrict",
 710                 .data           = &dmesg_restrict,
 711                 .maxlen         = sizeof(int),
 712                 .mode           = 0644,
 713                 .proc_handler   = proc_dointvec_minmax_sysadmin,
 714                 .extra1         = &zero,
 715                 .extra2         = &one,
 716         },
 717         {
 718                 .procname       = "kptr_restrict",
 719                 .data           = &kptr_restrict,
 720                 .maxlen         = sizeof(int),
 721                 .mode           = 0644,
 722                 .proc_handler   = proc_dointvec_minmax_sysadmin,
 723                 .extra1         = &zero,
 724                 .extra2         = &two,
 725         },
 726 #endif
 727         {
 728                 .procname       = "ngroups_max",
 729                 .data           = &ngroups_max,
 730                 .maxlen         = sizeof (int),
 731                 .mode           = 0444,
 732                 .proc_handler   = proc_dointvec,
 733         },
 734 #if defined(CONFIG_LOCKUP_DETECTOR)
 735         {
 736                 .procname       = "watchdog",
 737                 .data           = &watchdog_enabled,
 738                 .maxlen         = sizeof (int),
 739                 .mode           = 0644,
 740                 .proc_handler   = proc_dowatchdog,
 741                 .extra1         = &zero,
 742                 .extra2         = &one,
 743         },
 744         {
 745                 .procname       = "watchdog_thresh",
 746                 .data           = &watchdog_thresh,
 747                 .maxlen         = sizeof(int),
 748                 .mode           = 0644,
 749                 .proc_handler   = proc_dowatchdog,
 750                 .extra1         = &neg_one,
 751                 .extra2         = &sixty,
 752         },
 753         {
 754                 .procname       = "softlockup_panic",
 755                 .data           = &softlockup_panic,
 756                 .maxlen         = sizeof(int),
 757                 .mode           = 0644,
 758                 .proc_handler   = proc_dointvec_minmax,
 759                 .extra1         = &zero,
 760                 .extra2         = &one,
 761         },
 762         {
 763                 .procname       = "nmi_watchdog",
 764                 .data           = &watchdog_enabled,
 765                 .maxlen         = sizeof (int),
 766                 .mode           = 0644,
 767                 .proc_handler   = proc_dowatchdog,
 768                 .extra1         = &zero,
 769                 .extra2         = &one,
 770         },
 771 #endif
 772 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 773         {
 774                 .procname       = "unknown_nmi_panic",
 775                 .data           = &unknown_nmi_panic,
 776                 .maxlen         = sizeof (int),
 777                 .mode           = 0644,
 778                 .proc_handler   = proc_dointvec,
 779         },
 780 #endif
 781 #if defined(CONFIG_X86)
 782         {
 783                 .procname       = "panic_on_unrecovered_nmi",
 784                 .data           = &panic_on_unrecovered_nmi,
 785                 .maxlen         = sizeof(int),
 786                 .mode           = 0644,
 787                 .proc_handler   = proc_dointvec,
 788         },
 789         {
 790                 .procname       = "panic_on_io_nmi",
 791                 .data           = &panic_on_io_nmi,
 792                 .maxlen         = sizeof(int),
 793                 .mode           = 0644,
 794                 .proc_handler   = proc_dointvec,
 795         },
 796         {
 797                 .procname       = "bootloader_type",
 798                 .data           = &bootloader_type,
 799                 .maxlen         = sizeof (int),
 800                 .mode           = 0444,
 801                 .proc_handler   = proc_dointvec,
 802         },
 803         {
 804                 .procname       = "bootloader_version",
 805                 .data           = &bootloader_version,
 806                 .maxlen         = sizeof (int),
 807                 .mode           = 0444,
 808                 .proc_handler   = proc_dointvec,
 809         },
 810         {
 811                 .procname       = "kstack_depth_to_print",
 812                 .data           = &kstack_depth_to_print,
 813                 .maxlen         = sizeof(int),
 814                 .mode           = 0644,
 815                 .proc_handler   = proc_dointvec,
 816         },
 817         {
 818                 .procname       = "io_delay_type",
 819                 .data           = &io_delay_type,
 820                 .maxlen         = sizeof(int),
 821                 .mode           = 0644,
 822                 .proc_handler   = proc_dointvec,
 823         },
 824 #endif
 825 #if defined(CONFIG_MMU)
 826         {
 827                 .procname       = "randomize_va_space",
 828                 .data           = &randomize_va_space,
 829                 .maxlen         = sizeof(int),
 830                 .mode           = 0644,
 831                 .proc_handler   = proc_dointvec,
 832         },
 833 #endif
 834 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 835         {
 836                 .procname       = "spin_retry",
 837                 .data           = &spin_retry,
 838                 .maxlen         = sizeof (int),
 839                 .mode           = 0644,
 840                 .proc_handler   = proc_dointvec,
 841         },
 842 #endif
 843 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 844         {
 845                 .procname       = "acpi_video_flags",
 846                 .data           = &acpi_realmode_flags,
 847                 .maxlen         = sizeof (unsigned long),
 848                 .mode           = 0644,
 849                 .proc_handler   = proc_doulongvec_minmax,
 850         },
 851 #endif
 852 #ifdef CONFIG_IA64
 853         {
 854                 .procname       = "ignore-unaligned-usertrap",
 855                 .data           = &no_unaligned_warning,
 856                 .maxlen         = sizeof (int),
 857                 .mode           = 0644,
 858                 .proc_handler   = proc_dointvec,
 859         },
 860         {
 861                 .procname       = "unaligned-dump-stack",
 862                 .data           = &unaligned_dump_stack,
 863                 .maxlen         = sizeof (int),
 864                 .mode           = 0644,
 865                 .proc_handler   = proc_dointvec,
 866         },
 867 #endif
 868 #ifdef CONFIG_DETECT_HUNG_TASK
 869         {
 870                 .procname       = "hung_task_panic",
 871                 .data           = &sysctl_hung_task_panic,
 872                 .maxlen         = sizeof(int),
 873                 .mode           = 0644,
 874                 .proc_handler   = proc_dointvec_minmax,
 875                 .extra1         = &zero,
 876                 .extra2         = &one,
 877         },
 878         {
 879                 .procname       = "hung_task_check_count",
 880                 .data           = &sysctl_hung_task_check_count,
 881                 .maxlen         = sizeof(unsigned long),
 882                 .mode           = 0644,
 883                 .proc_handler   = proc_doulongvec_minmax,
 884         },
 885         {
 886                 .procname       = "hung_task_timeout_secs",
 887                 .data           = &sysctl_hung_task_timeout_secs,
 888                 .maxlen         = sizeof(unsigned long),
 889                 .mode           = 0644,
 890                 .proc_handler   = proc_dohung_task_timeout_secs,
 891         },
 892         {
 893                 .procname       = "hung_task_warnings",
 894                 .data           = &sysctl_hung_task_warnings,
 895                 .maxlen         = sizeof(unsigned long),
 896                 .mode           = 0644,
 897                 .proc_handler   = proc_doulongvec_minmax,
 898         },
 899 #endif
 900 #ifdef CONFIG_COMPAT
 901         {
 902                 .procname       = "compat-log",
 903                 .data           = &compat_log,
 904                 .maxlen         = sizeof (int),
 905                 .mode           = 0644,
 906                 .proc_handler   = proc_dointvec,
 907         },
 908 #endif
 909 #ifdef CONFIG_RT_MUTEXES
 910         {
 911                 .procname       = "max_lock_depth",
 912                 .data           = &max_lock_depth,
 913                 .maxlen         = sizeof(int),
 914                 .mode           = 0644,
 915                 .proc_handler   = proc_dointvec,
 916         },
 917 #endif
 918         {
 919                 .procname       = "poweroff_cmd",
 920                 .data           = &poweroff_cmd,
 921                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 922                 .mode           = 0644,
 923                 .proc_handler   = proc_dostring,
 924         },
 925 #ifdef CONFIG_KEYS
 926         {
 927                 .procname       = "keys",
 928                 .mode           = 0555,
 929                 .child          = key_sysctls,
 930         },
 931 #endif
 932 #ifdef CONFIG_RCU_TORTURE_TEST
 933         {
 934                 .procname       = "rcutorture_runnable",
 935                 .data           = &rcutorture_runnable,
 936                 .maxlen         = sizeof(int),
 937                 .mode           = 0644,
 938                 .proc_handler   = proc_dointvec,
 939         },
 940 #endif
 941 #ifdef CONFIG_PERF_EVENTS
 942         /*
 943          * User-space scripts rely on the existence of this file
 944          * as a feature check for perf_events being enabled.
 945          *
 946          * So it's an ABI, do not remove!
 947          */
 948         {
 949                 .procname       = "perf_event_paranoid",
 950                 .data           = &sysctl_perf_event_paranoid,
 951                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 952                 .mode           = 0644,
 953                 .proc_handler   = proc_dointvec,
 954         },
 955         {
 956                 .procname       = "perf_event_mlock_kb",
 957                 .data           = &sysctl_perf_event_mlock,
 958                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 959                 .mode           = 0644,
 960                 .proc_handler   = proc_dointvec,
 961         },
 962         {
 963                 .procname       = "perf_event_max_sample_rate",
 964                 .data           = &sysctl_perf_event_sample_rate,
 965                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 966                 .mode           = 0644,
 967                 .proc_handler   = perf_proc_update_handler,
 968         },
 969 #endif
 970 #ifdef CONFIG_KMEMCHECK
 971         {
 972                 .procname       = "kmemcheck",
 973                 .data           = &kmemcheck_enabled,
 974                 .maxlen         = sizeof(int),
 975                 .mode           = 0644,
 976                 .proc_handler   = proc_dointvec,
 977         },
 978 #endif
 979 #ifdef CONFIG_BLOCK
 980         {
 981                 .procname       = "blk_iopoll",
 982                 .data           = &blk_iopoll_enabled,
 983                 .maxlen         = sizeof(int),
 984                 .mode           = 0644,
 985                 .proc_handler   = proc_dointvec,
 986         },
 987 #endif
 988         { }
 989 };
 990
 991 static struct ctl_table vm_table[] = {
 992         {
 993                 .procname       = "overcommit_memory",
 994                 .data           = &sysctl_overcommit_memory,
 995                 .maxlen         = sizeof(sysctl_overcommit_memory),
 996                 .mode           = 0644,
 997                 .proc_handler   = proc_dointvec_minmax,
 998                 .extra1         = &zero,
 999                 .extra2         = &two,
1000         },
1001         {
1002                 .procname       = "panic_on_oom",
1003                 .data           = &sysctl_panic_on_oom,
1004                 .maxlen         = sizeof(sysctl_panic_on_oom),
1005                 .mode           = 0644,
1006                 .proc_handler   = proc_dointvec_minmax,
1007                 .extra1         = &zero,
1008                 .extra2         = &two,
1009         },
1010         {
1011                 .procname       = "oom_kill_allocating_task",
1012                 .data           = &sysctl_oom_kill_allocating_task,
1013                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1014                 .mode           = 0644,
1015                 .proc_handler   = proc_dointvec,
1016         },
1017         {
1018                 .procname       = "oom_dump_tasks",
1019                 .data           = &sysctl_oom_dump_tasks,
1020                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1021                 .mode           = 0644,
1022                 .proc_handler   = proc_dointvec,
1023         },
1024         {
1025                 .procname       = "overcommit_ratio",
1026                 .data           = &sysctl_overcommit_ratio,
1027                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1028                 .mode           = 0644,
1029                 .proc_handler   = proc_dointvec,
1030         },
1031         {
1032                 .procname       = "page-cluster",
1033                 .data           = &page_cluster,
1034                 .maxlen         = sizeof(int),
1035                 .mode           = 0644,
1036                 .proc_handler   = proc_dointvec_minmax,
1037                 .extra1         = &zero,
1038         },
1039         {
1040                 .procname       = "dirty_background_ratio",
1041                 .data           = &dirty_background_ratio,
1042                 .maxlen         = sizeof(dirty_background_ratio),
1043                 .mode           = 0644,
1044                 .proc_handler   = dirty_background_ratio_handler,
1045                 .extra1         = &zero,
1046                 .extra2         = &one_hundred,
1047         },
1048         {
1049                 .procname       = "dirty_background_bytes",
1050                 .data           = &dirty_background_bytes,
1051                 .maxlen         = sizeof(dirty_background_bytes),
1052                 .mode           = 0644,
1053                 .proc_handler   = dirty_background_bytes_handler,
1054                 .extra1         = &one_ul,
1055         },
1056         {
1057                 .procname       = "dirty_ratio",
1058                 .data           = &vm_dirty_ratio,
1059                 .maxlen         = sizeof(vm_dirty_ratio),
1060                 .mode           = 0644,
1061                 .proc_handler   = dirty_ratio_handler,
1062                 .extra1         = &zero,
1063                 .extra2         = &one_hundred,
1064         },
1065         {
1066                 .procname       = "dirty_bytes",
1067                 .data           = &vm_dirty_bytes,
1068                 .maxlen         = sizeof(vm_dirty_bytes),
1069                 .mode           = 0644,
1070                 .proc_handler   = dirty_bytes_handler,
1071                 .extra1         = &dirty_bytes_min,
1072         },
1073         {
1074                 .procname       = "dirty_writeback_centisecs",
1075                 .data           = &dirty_writeback_interval,
1076                 .maxlen         = sizeof(dirty_writeback_interval),
1077                 .mode           = 0644,
1078                 .proc_handler   = dirty_writeback_centisecs_handler,
1079         },
1080         {
1081                 .procname       = "dirty_expire_centisecs",
1082                 .data           = &dirty_expire_interval,
1083                 .maxlen         = sizeof(dirty_expire_interval),
1084                 .mode           = 0644,
1085                 .proc_handler   = proc_dointvec_minmax,
1086                 .extra1         = &zero,
1087         },
1088         {
1089                 .procname       = "nr_pdflush_threads",
1090                 .data           = &nr_pdflush_threads,
1091                 .maxlen         = sizeof nr_pdflush_threads,
1092                 .mode           = 0444 /* read-only*/,
1093                 .proc_handler   = proc_dointvec,
1094         },
1095         {
1096                 .procname       = "swappiness",
1097                 .data           = &vm_swappiness,
1098                 .maxlen         = sizeof(vm_swappiness),
1099                 .mode           = 0644,
1100                 .proc_handler   = proc_dointvec_minmax,
1101                 .extra1         = &zero,
1102                 .extra2         = &one_hundred,
1103         },
1104 #ifdef CONFIG_HUGETLB_PAGE
1105         {
1106                 .procname       = "nr_hugepages",
1107                 .data           = NULL,
1108                 .maxlen         = sizeof(unsigned long),
1109                 .mode           = 0644,
1110                 .proc_handler   = hugetlb_sysctl_handler,
1111                 .extra1         = (void *)&hugetlb_zero,
1112                 .extra2         = (void *)&hugetlb_infinity,
1113         },
1114 #ifdef CONFIG_NUMA
1115         {
1116                 .procname       = "nr_hugepages_mempolicy",
1117                 .data           = NULL,
1118                 .maxlen         = sizeof(unsigned long),
1119                 .mode           = 0644,
1120                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1121                 .extra1         = (void *)&hugetlb_zero,
1122                 .extra2         = (void *)&hugetlb_infinity,
1123         },
1124 #endif
1125          {
1126                 .procname       = "hugetlb_shm_group",
1127                 .data           = &sysctl_hugetlb_shm_group,
1128                 .maxlen         = sizeof(gid_t),
1129                 .mode           = 0644,
1130                 .proc_handler   = proc_dointvec,
1131          },
1132          {
1133                 .procname       = "hugepages_treat_as_movable",
1134                 .data           = &hugepages_treat_as_movable,
1135                 .maxlen         = sizeof(int),
1136                 .mode           = 0644,
1137                 .proc_handler   = hugetlb_treat_movable_handler,
1138         },
1139         {
1140                 .procname       = "nr_overcommit_hugepages",
1141                 .data           = NULL,
1142                 .maxlen         = sizeof(unsigned long),
1143                 .mode           = 0644,
1144                 .proc_handler   = hugetlb_overcommit_handler,
1145                 .extra1         = (void *)&hugetlb_zero,
1146                 .extra2         = (void *)&hugetlb_infinity,
1147         },
1148 #endif
1149         {
1150                 .procname       = "lowmem_reserve_ratio",
1151                 .data           = &sysctl_lowmem_reserve_ratio,
1152                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1153                 .mode           = 0644,
1154                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1155         },
1156         {
1157                 .procname       = "drop_caches",
1158                 .data           = &sysctl_drop_caches,
1159                 .maxlen         = sizeof(int),
1160                 .mode           = 0644,
1161                 .proc_handler   = drop_caches_sysctl_handler,
1162                 .extra1         = &one,
1163                 .extra2         = &three,
1164         },
1165 #ifdef CONFIG_COMPACTION
1166         {
1167                 .procname       = "compact_memory",
1168                 .data           = &sysctl_compact_memory,
1169                 .maxlen         = sizeof(int),
1170                 .mode           = 0200,
1171                 .proc_handler   = sysctl_compaction_handler,
1172         },
1173         {
1174                 .procname       = "extfrag_threshold",
1175                 .data           = &sysctl_extfrag_threshold,
1176                 .maxlen         = sizeof(int),
1177                 .mode           = 0644,
1178                 .proc_handler   = sysctl_extfrag_handler,
1179                 .extra1         = &min_extfrag_threshold,
1180                 .extra2         = &max_extfrag_threshold,
1181         },
1182
1183 #endif /* CONFIG_COMPACTION */
1184         {
1185                 .procname       = "min_free_kbytes",
1186                 .data           = &min_free_kbytes,
1187                 .maxlen         = sizeof(min_free_kbytes),
1188                 .mode           = 0644,
1189                 .proc_handler   = min_free_kbytes_sysctl_handler,
1190                 .extra1         = &zero,
1191         },
1192         {
1193                 .procname       = "min_free_order_shift",
1194                 .data           = &min_free_order_shift,
1195                 .maxlen         = sizeof(min_free_order_shift),
1196                 .mode           = 0644,
1197                 .proc_handler   = &proc_dointvec
1198         },
1199         {
1200                 .procname       = "percpu_pagelist_fraction",
1201                 .data           = &percpu_pagelist_fraction,
1202                 .maxlen         = sizeof(percpu_pagelist_fraction),
1203                 .mode           = 0644,
1204                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1205                 .extra1         = &min_percpu_pagelist_fract,
1206         },
1207 #ifdef CONFIG_MMU
1208         {
1209                 .procname       = "max_map_count",
1210                 .data           = &sysctl_max_map_count,
1211                 .maxlen         = sizeof(sysctl_max_map_count),
1212                 .mode           = 0644,
1213                 .proc_handler   = proc_dointvec_minmax,
1214                 .extra1         = &zero,
1215         },
1216 #else
1217         {
1218                 .procname       = "nr_trim_pages",
1219                 .data           = &sysctl_nr_trim_pages,
1220                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1221                 .mode           = 0644,
1222                 .proc_handler   = proc_dointvec_minmax,
1223                 .extra1         = &zero,
1224         },
1225 #endif
1226         {
1227                 .procname       = "laptop_mode",
1228                 .data           = &laptop_mode,
1229                 .maxlen         = sizeof(laptop_mode),
1230                 .mode           = 0644,
1231                 .proc_handler   = proc_dointvec_jiffies,
1232         },
1233         {
1234                 .procname       = "block_dump",
1235                 .data           = &block_dump,
1236                 .maxlen         = sizeof(block_dump),
1237                 .mode           = 0644,
1238                 .proc_handler   = proc_dointvec,
1239                 .extra1         = &zero,
1240         },
1241         {
1242                 .procname       = "vfs_cache_pressure",
1243                 .data           = &sysctl_vfs_cache_pressure,
1244                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1245                 .mode           = 0644,
1246                 .proc_handler   = proc_dointvec,
1247                 .extra1         = &zero,
1248         },
1249 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1250         {
1251                 .procname       = "legacy_va_layout",
1252                 .data           = &sysctl_legacy_va_layout,
1253                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1254                 .mode           = 0644,
1255                 .proc_handler   = proc_dointvec,
1256                 .extra1         = &zero,
1257         },
1258 #endif
1259 #ifdef CONFIG_NUMA
1260         {
1261                 .procname       = "zone_reclaim_mode",
1262                 .data           = &zone_reclaim_mode,
1263                 .maxlen         = sizeof(zone_reclaim_mode),
1264                 .mode           = 0644,
1265                 .proc_handler   = proc_dointvec,
1266                 .extra1         = &zero,
1267         },
1268         {
1269                 .procname       = "min_unmapped_ratio",
1270                 .data           = &sysctl_min_unmapped_ratio,
1271                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1272                 .mode           = 0644,
1273                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1274                 .extra1         = &zero,
1275                 .extra2         = &one_hundred,
1276         },
1277         {
1278                 .procname       = "min_slab_ratio",
1279                 .data           = &sysctl_min_slab_ratio,
1280                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1281                 .mode           = 0644,
1282                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1283                 .extra1         = &zero,
1284                 .extra2         = &one_hundred,
1285         },
1286 #endif
1287 #ifdef CONFIG_SMP
1288         {
1289                 .procname       = "stat_interval",
1290                 .data           = &sysctl_stat_interval,
1291                 .maxlen         = sizeof(sysctl_stat_interval),
1292                 .mode           = 0644,
1293                 .proc_handler   = proc_dointvec_jiffies,
1294         },
1295 #endif
1296 #ifdef CONFIG_MMU
1297         {
1298                 .procname       = "mmap_min_addr",
1299                 .data           = &dac_mmap_min_addr,
1300                 .maxlen         = sizeof(unsigned long),
1301                 .mode           = 0644,
1302                 .proc_handler   = mmap_min_addr_handler,
1303         },
1304 #endif
1305 #ifdef CONFIG_NUMA
1306         {
1307                 .procname       = "numa_zonelist_order",
1308                 .data           = &numa_zonelist_order,
1309                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1310                 .mode           = 0644,
1311                 .proc_handler   = numa_zonelist_order_handler,
1312         },
1313 #endif
1314 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1315    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1316         {
1317                 .procname       = "vdso_enabled",
1318                 .data           = &vdso_enabled,
1319                 .maxlen         = sizeof(vdso_enabled),
1320                 .mode           = 0644,
1321                 .proc_handler   = proc_dointvec,
1322                 .extra1         = &zero,
1323         },
1324 #endif
1325 #ifdef CONFIG_HIGHMEM
1326         {
1327                 .procname       = "highmem_is_dirtyable",
1328                 .data           = &vm_highmem_is_dirtyable,
1329                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1330                 .mode           = 0644,
1331                 .proc_handler   = proc_dointvec_minmax,
1332                 .extra1         = &zero,
1333                 .extra2         = &one,
1334         },
1335 #endif
1336         {
1337                 .procname       = "scan_unevictable_pages",
1338                 .data           = &scan_unevictable_pages,
1339                 .maxlen         = sizeof(scan_unevictable_pages),
1340                 .mode           = 0644,
1341                 .proc_handler   = scan_unevictable_handler,
1342         },
1343 #ifdef CONFIG_MEMORY_FAILURE
1344         {
1345                 .procname       = "memory_failure_early_kill",
1346                 .data           = &sysctl_memory_failure_early_kill,
1347                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1348                 .mode           = 0644,
1349                 .proc_handler   = proc_dointvec_minmax,
1350                 .extra1         = &zero,
1351                 .extra2         = &one,
1352         },
1353         {
1354                 .procname       = "memory_failure_recovery",
1355                 .data           = &sysctl_memory_failure_recovery,
1356                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1357                 .mode           = 0644,
1358                 .proc_handler   = proc_dointvec_minmax,
1359                 .extra1         = &zero,
1360                 .extra2         = &one,
1361         },
1362 #endif
1363         { }
1364 };
1365
1366 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1367 static struct ctl_table binfmt_misc_table[] = {
1368         { }
1369 };
1370 #endif
1371
1372 static struct ctl_table fs_table[] = {
1373         {
1374                 .procname       = "inode-nr",
1375                 .data           = &inodes_stat,
1376                 .maxlen         = 2*sizeof(int),
1377                 .mode           = 0444,
1378                 .proc_handler   = proc_nr_inodes,
1379         },
1380         {
1381                 .procname       = "inode-state",
1382                 .data           = &inodes_stat,
1383                 .maxlen         = 7*sizeof(int),
1384                 .mode           = 0444,
1385                 .proc_handler   = proc_nr_inodes,
1386         },
1387         {
1388                 .procname       = "file-nr",
1389                 .data           = &files_stat,
1390                 .maxlen         = sizeof(files_stat),
1391                 .mode           = 0444,
1392                 .proc_handler   = proc_nr_files,
1393         },
1394         {
1395                 .procname       = "file-max",
1396                 .data           = &files_stat.max_files,
1397                 .maxlen         = sizeof(files_stat.max_files),
1398                 .mode           = 0644,
1399                 .proc_handler   = proc_doulongvec_minmax,
1400         },
1401         {
1402                 .procname       = "nr_open",
1403                 .data           = &sysctl_nr_open,
1404                 .maxlen         = sizeof(int),
1405                 .mode           = 0644,
1406                 .proc_handler   = proc_dointvec_minmax,
1407                 .extra1         = &sysctl_nr_open_min,
1408                 .extra2         = &sysctl_nr_open_max,
1409         },
1410         {
1411                 .procname       = "dentry-state",
1412                 .data           = &dentry_stat,
1413                 .maxlen         = 6*sizeof(int),
1414                 .mode           = 0444,
1415                 .proc_handler   = proc_nr_dentry,
1416         },
1417         {
1418                 .procname       = "overflowuid",
1419                 .data           = &fs_overflowuid,
1420                 .maxlen         = sizeof(int),
1421                 .mode           = 0644,
1422                 .proc_handler   = proc_dointvec_minmax,
1423                 .extra1         = &minolduid,
1424                 .extra2         = &maxolduid,
1425         },
1426         {
1427                 .procname       = "overflowgid",
1428                 .data           = &fs_overflowgid,
1429                 .maxlen         = sizeof(int),
1430                 .mode           = 0644,
1431                 .proc_handler   = proc_dointvec_minmax,
1432                 .extra1         = &minolduid,
1433                 .extra2         = &maxolduid,
1434         },
1435 #ifdef CONFIG_FILE_LOCKING
1436         {
1437                 .procname       = "leases-enable",
1438                 .data           = &leases_enable,
1439                 .maxlen         = sizeof(int),
1440                 .mode           = 0644,
1441                 .proc_handler   = proc_dointvec,
1442         },
1443 #endif
1444 #ifdef CONFIG_DNOTIFY
1445         {
1446                 .procname       = "dir-notify-enable",
1447                 .data           = &dir_notify_enable,
1448                 .maxlen         = sizeof(int),
1449                 .mode           = 0644,
1450                 .proc_handler   = proc_dointvec,
1451         },
1452 #endif
1453 #ifdef CONFIG_MMU
1454 #ifdef CONFIG_FILE_LOCKING
1455         {
1456                 .procname       = "lease-break-time",
1457                 .data           = &lease_break_time,
1458                 .maxlen         = sizeof(int),
1459                 .mode           = 0644,
1460                 .proc_handler   = proc_dointvec,
1461         },
1462 #endif
1463 #ifdef CONFIG_AIO
1464         {
1465                 .procname       = "aio-nr",
1466                 .data           = &aio_nr,
1467                 .maxlen         = sizeof(aio_nr),
1468                 .mode           = 0444,
1469                 .proc_handler   = proc_doulongvec_minmax,
1470         },
1471         {
1472                 .procname       = "aio-max-nr",
1473                 .data           = &aio_max_nr,
1474                 .maxlen         = sizeof(aio_max_nr),
1475                 .mode           = 0644,
1476                 .proc_handler   = proc_doulongvec_minmax,
1477         },
1478 #endif /* CONFIG_AIO */
1479 #ifdef CONFIG_INOTIFY_USER
1480         {
1481                 .procname       = "inotify",
1482                 .mode           = 0555,
1483                 .child          = inotify_table,
1484         },
1485 #endif
1486 #ifdef CONFIG_EPOLL
1487         {
1488                 .procname       = "epoll",
1489                 .mode           = 0555,
1490                 .child          = epoll_table,
1491         },
1492 #endif
1493 #endif
1494         {
1495                 .procname       = "suid_dumpable",
1496                 .data           = &suid_dumpable,
1497                 .maxlen         = sizeof(int),
1498                 .mode           = 0644,
1499                 .proc_handler   = proc_dointvec_minmax,
1500                 .extra1         = &zero,
1501                 .extra2         = &two,
1502         },
1503 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1504         {
1505                 .procname       = "binfmt_misc",
1506                 .mode           = 0555,
1507                 .child          = binfmt_misc_table,
1508         },
1509 #endif
1510         {
1511                 .procname       = "pipe-max-size",
1512                 .data           = &pipe_max_size,
1513                 .maxlen         = sizeof(int),
1514                 .mode           = 0644,
1515                 .proc_handler   = &pipe_proc_fn,
1516                 .extra1         = &pipe_min_size,
1517         },
1518         { }
1519 };
1520
1521 static struct ctl_table debug_table[] = {
1522 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1523     defined(CONFIG_S390) || defined(CONFIG_TILE)
1524         {
1525                 .procname       = "exception-trace",
1526                 .data           = &show_unhandled_signals,
1527                 .maxlen         = sizeof(int),
1528                 .mode           = 0644,
1529                 .proc_handler   = proc_dointvec
1530         },
1531 #endif
1532 #if defined(CONFIG_OPTPROBES)
1533         {
1534                 .procname       = "kprobes-optimization",
1535                 .data           = &sysctl_kprobes_optimization,
1536                 .maxlen         = sizeof(int),
1537                 .mode           = 0644,
1538                 .proc_handler   = proc_kprobes_optimization_handler,
1539                 .extra1         = &zero,
1540                 .extra2         = &one,
1541         },
1542 #endif
1543         { }
1544 };
1545
1546 static struct ctl_table dev_table[] = {
1547         { }
1548 };
1549
1550 static DEFINE_SPINLOCK(sysctl_lock);
1551
1552 /* called under sysctl_lock */
1553 static int use_table(struct ctl_table_header *p)
1554 {
1555         if (unlikely(p->unregistering))
1556                 return 0;
1557         p->used++;
1558         return 1;
1559 }
1560
1561 /* called under sysctl_lock */
1562 static void unuse_table(struct ctl_table_header *p)
1563 {
1564         if (!--p->used)
1565                 if (unlikely(p->unregistering))
1566                         complete(p->unregistering);
1567 }
1568
1569 /* called under sysctl_lock, will reacquire if has to wait */
1570 static void start_unregistering(struct ctl_table_header *p)
1571 {
1572         /*
1573          * if p->used is 0, nobody will ever touch that entry again;
1574          * we'll eliminate all paths to it before dropping sysctl_lock
1575          */
1576         if (unlikely(p->used)) {
1577                 struct completion wait;
1578                 init_completion(&wait);
1579                 p->unregistering = &wait;
1580                 spin_unlock(&sysctl_lock);
1581                 wait_for_completion(&wait);
1582                 spin_lock(&sysctl_lock);
1583         } else {
1584                 /* anything non-NULL; we'll never dereference it */
1585                 p->unregistering = ERR_PTR(-EINVAL);
1586         }
1587         /*
1588          * do not remove from the list until nobody holds it; walking the
1589          * list in do_sysctl() relies on that.
1590          */
1591         list_del_init(&p->ctl_entry);
1592 }
1593
1594 void sysctl_head_get(struct ctl_table_header *head)
1595 {
1596         spin_lock(&sysctl_lock);
1597         head->count++;
1598         spin_unlock(&sysctl_lock);
1599 }
1600
1601 static void free_head(struct rcu_head *rcu)
1602 {
1603         kfree(container_of(rcu, struct ctl_table_header, rcu));
1604 }
1605
1606 void sysctl_head_put(struct ctl_table_header *head)
1607 {
1608         spin_lock(&sysctl_lock);
1609         if (!--head->count)
1610                 call_rcu(&head->rcu, free_head);
1611         spin_unlock(&sysctl_lock);
1612 }
1613
1614 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1615 {
1616         if (!head)
1617                 BUG();
1618         spin_lock(&sysctl_lock);
1619         if (!use_table(head))
1620                 head = ERR_PTR(-ENOENT);
1621         spin_unlock(&sysctl_lock);
1622         return head;
1623 }
1624
1625 void sysctl_head_finish(struct ctl_table_header *head)
1626 {
1627         if (!head)
1628                 return;
1629         spin_lock(&sysctl_lock);
1630         unuse_table(head);
1631         spin_unlock(&sysctl_lock);
1632 }
1633
1634 static struct ctl_table_set *
1635 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1636 {
1637         struct ctl_table_set *set = &root->default_set;
1638         if (root->lookup)
1639                 set = root->lookup(root, namespaces);
1640         return set;
1641 }
1642
1643 static struct list_head *
1644 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1645 {
1646         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1647         return &set->list;
1648 }
1649
1650 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1651                                             struct ctl_table_header *prev)
1652 {
1653         struct ctl_table_root *root;
1654         struct list_head *header_list;
1655         struct ctl_table_header *head;
1656         struct list_head *tmp;
1657
1658         spin_lock(&sysctl_lock);
1659         if (prev) {
1660                 head = prev;
1661                 tmp = &prev->ctl_entry;
1662                 unuse_table(prev);
1663                 goto next;
1664         }
1665         tmp = &root_table_header.ctl_entry;
1666         for (;;) {
1667                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1668
1669                 if (!use_table(head))
1670                         goto next;
1671                 spin_unlock(&sysctl_lock);
1672                 return head;
1673         next:
1674                 root = head->root;
1675                 tmp = tmp->next;
1676                 header_list = lookup_header_list(root, namespaces);
1677                 if (tmp != header_list)
1678                         continue;
1679
1680                 do {
1681                         root = list_entry(root->root_list.next,
1682                                         struct ctl_table_root, root_list);
1683                         if (root == &sysctl_table_root)
1684                                 goto out;
1685                         header_list = lookup_header_list(root, namespaces);
1686                 } while (list_empty(header_list));
1687                 tmp = header_list->next;
1688         }
1689 out:
1690         spin_unlock(&sysctl_lock);
1691         return NULL;
1692 }
1693
1694 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1695 {
1696         return __sysctl_head_next(current->nsproxy, prev);
1697 }
1698
1699 void register_sysctl_root(struct ctl_table_root *root)
1700 {
1701         spin_lock(&sysctl_lock);
1702         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1703         spin_unlock(&sysctl_lock);
1704 }
1705
1706 /*
1707  * sysctl_perm does NOT grant the superuser all rights automatically, because
1708  * some sysctl variables are readonly even to root.
1709  */
1710
1711 static int test_perm(int mode, int op)
1712 {
1713         if (!current_euid())
1714                 mode >>= 6;
1715         else if (in_egroup_p(0))
1716                 mode >>= 3;
1717         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1718                 return 0;
1719         return -EACCES;
1720 }
1721
1722 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1723 {
1724         int mode;
1725
1726         if (root->permissions)
1727                 mode = root->permissions(root, current->nsproxy, table);
1728         else
1729                 mode = table->mode;
1730
1731         return test_perm(mode, op);
1732 }
1733
1734 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1735 {
1736         for (; table->procname; table++) {
1737                 table->parent = parent;
1738                 if (table->child)
1739                         sysctl_set_parent(table, table->child);
1740         }
1741 }
1742
1743 static __init int sysctl_init(void)
1744 {
1745         sysctl_set_parent(NULL, root_table);
1746 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1747         sysctl_check_table(current->nsproxy, root_table);
1748 #endif
1749         return 0;
1750 }
1751
1752 core_initcall(sysctl_init);
1753
1754 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1755                                       struct ctl_table *table)
1756 {
1757         struct ctl_table *p;
1758         const char *s = branch->procname;
1759
1760         /* branch should have named subdirectory as its first element */
1761         if (!s || !branch->child)
1762                 return NULL;
1763
1764         /* ... and nothing else */
1765         if (branch[1].procname)
1766                 return NULL;
1767
1768         /* table should contain subdirectory with the same name */
1769         for (p = table; p->procname; p++) {
1770                 if (!p->child)
1771                         continue;
1772                 if (p->procname && strcmp(p->procname, s) == 0)
1773                         return p;
1774         }
1775         return NULL;
1776 }
1777
1778 /* see if attaching q to p would be an improvement */
1779 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1780 {
1781         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1782         struct ctl_table *next;
1783         int is_better = 0;
1784         int not_in_parent = !p->attached_by;
1785
1786         while ((next = is_branch_in(by, to)) != NULL) {
1787                 if (by == q->attached_by)
1788                         is_better = 1;
1789                 if (to == p->attached_by)
1790                         not_in_parent = 1;
1791                 by = by->child;
1792                 to = next->child;
1793         }
1794
1795         if (is_better && not_in_parent) {
1796                 q->attached_by = by;
1797                 q->attached_to = to;
1798                 q->parent = p;
1799         }
1800 }
1801
1802 /**
1803  * __register_sysctl_paths - register a sysctl hierarchy
1804  * @root: List of sysctl headers to register on
1805  * @namespaces: Data to compute which lists of sysctl entries are visible
1806  * @path: The path to the directory the sysctl table is in.
1807  * @table: the top-level table structure
1808  *
1809  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1810  * array. A completely 0 filled entry terminates the table.
1811  *
1812  * The members of the &struct ctl_table structure are used as follows:
1813  *
1814  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1815  *            enter a sysctl file
1816  *
1817  * data - a pointer to data for use by proc_handler
1818  *
1819  * maxlen - the maximum size in bytes of the data
1820  *
1821  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1822  *
1823  * child - a pointer to the child sysctl table if this entry is a directory, or
1824  *         %NULL.
1825  *
1826  * proc_handler - the text handler routine (described below)
1827  *
1828  * de - for internal use by the sysctl routines
1829  *
1830  * extra1, extra2 - extra pointers usable by the proc handler routines
1831  *
1832  * Leaf nodes in the sysctl tree will be represented by a single file
1833  * under /proc; non-leaf nodes will be represented by directories.
1834  *
1835  * sysctl(2) can automatically manage read and write requests through
1836  * the sysctl table.  The data and maxlen fields of the ctl_table
1837  * struct enable minimal validation of the values being written to be
1838  * performed, and the mode field allows minimal authentication.
1839  *
1840  * There must be a proc_handler routine for any terminal nodes
1841  * mirrored under /proc/sys (non-terminals are handled by a built-in
1842  * directory handler).  Several default handlers are available to
1843  * cover common cases -
1844  *
1845  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1846  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1847  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1848  *
1849  * It is the handler's job to read the input buffer from user memory
1850  * and process it. The handler should return 0 on success.
1851  *
1852  * This routine returns %NULL on a failure to register, and a pointer
1853  * to the table header on success.
1854  */
1855 struct ctl_table_header *__register_sysctl_paths(
1856         struct ctl_table_root *root,
1857         struct nsproxy *namespaces,
1858         const struct ctl_path *path, struct ctl_table *table)
1859 {
1860         struct ctl_table_header *header;
1861         struct ctl_table *new, **prevp;
1862         unsigned int n, npath;
1863         struct ctl_table_set *set;
1864
1865         /* Count the path components */
1866         for (npath = 0; path[npath].procname; ++npath)
1867                 ;
1868
1869         /*
1870          * For each path component, allocate a 2-element ctl_table array.
1871          * The first array element will be filled with the sysctl entry
1872          * for this, the second will be the sentinel (procname == 0).
1873          *
1874          * We allocate everything in one go so that we don't have to
1875          * worry about freeing additional memory in unregister_sysctl_table.
1876          */
1877         header = kzalloc(sizeof(struct ctl_table_header) +
1878                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1879         if (!header)
1880                 return NULL;
1881
1882         new = (struct ctl_table *) (header + 1);
1883
1884         /* Now connect the dots */
1885         prevp = &header->ctl_table;
1886         for (n = 0; n < npath; ++n, ++path) {
1887                 /* Copy the procname */
1888                 new->procname = path->procname;
1889                 new->mode     = 0555;
1890
1891                 *prevp = new;
1892                 prevp = &new->child;
1893
1894                 new += 2;
1895         }
1896         *prevp = table;
1897         header->ctl_table_arg = table;
1898
1899         INIT_LIST_HEAD(&header->ctl_entry);
1900         header->used = 0;
1901         header->unregistering = NULL;
1902         header->root = root;
1903         sysctl_set_parent(NULL, header->ctl_table);
1904         header->count = 1;
1905 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1906         if (sysctl_check_table(namespaces, header->ctl_table)) {
1907                 kfree(header);
1908                 return NULL;
1909         }
1910 #endif
1911         spin_lock(&sysctl_lock);
1912         header->set = lookup_header_set(root, namespaces);
1913         header->attached_by = header->ctl_table;
1914         header->attached_to = root_table;
1915         header->parent = &root_table_header;
1916         for (set = header->set; set; set = set->parent) {
1917                 struct ctl_table_header *p;
1918                 list_for_each_entry(p, &set->list, ctl_entry) {
1919                         if (p->unregistering)
1920                                 continue;
1921                         try_attach(p, header);
1922                 }
1923         }
1924         header->parent->count++;
1925         list_add_tail(&header->ctl_entry, &header->set->list);
1926         spin_unlock(&sysctl_lock);
1927
1928         return header;
1929 }
1930
1931 /**
1932  * register_sysctl_table_path - register a sysctl table hierarchy
1933  * @path: The path to the directory the sysctl table is in.
1934  * @table: the top-level table structure
1935  *
1936  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1937  * array. A completely 0 filled entry terminates the table.
1938  *
1939  * See __register_sysctl_paths for more details.
1940  */
1941 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1942                                                 struct ctl_table *table)
1943 {
1944         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1945                                         path, table);
1946 }
1947
1948 /**
1949  * register_sysctl_table - register a sysctl table hierarchy
1950  * @table: the top-level table structure
1951  *
1952  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1953  * array. A completely 0 filled entry terminates the table.
1954  *
1955  * See register_sysctl_paths for more details.
1956  */
1957 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1958 {
1959         static const struct ctl_path null_path[] = { {} };
1960
1961         return register_sysctl_paths(null_path, table);
1962 }
1963
1964 /**
1965  * unregister_sysctl_table - unregister a sysctl table hierarchy
1966  * @header: the header returned from register_sysctl_table
1967  *
1968  * Unregisters the sysctl table and all children. proc entries may not
1969  * actually be removed until they are no longer used by anyone.
1970  */
1971 void unregister_sysctl_table(struct ctl_table_header * header)
1972 {
1973         might_sleep();
1974
1975         if (header == NULL)
1976                 return;
1977
1978         spin_lock(&sysctl_lock);
1979         start_unregistering(header);
1980         if (!--header->parent->count) {
1981                 WARN_ON(1);
1982                 call_rcu(&header->parent->rcu, free_head);
1983         }
1984         if (!--header->count)
1985                 call_rcu(&header->rcu, free_head);
1986         spin_unlock(&sysctl_lock);
1987 }
1988
1989 int sysctl_is_seen(struct ctl_table_header *p)
1990 {
1991         struct ctl_table_set *set = p->set;
1992         int res;
1993         spin_lock(&sysctl_lock);
1994         if (p->unregistering)
1995                 res = 0;
1996         else if (!set->is_seen)
1997                 res = 1;
1998         else
1999                 res = set->is_seen(set);
2000         spin_unlock(&sysctl_lock);
2001         return res;
2002 }
2003
2004 void setup_sysctl_set(struct ctl_table_set *p,
2005         struct ctl_table_set *parent,
2006         int (*is_seen)(struct ctl_table_set *))
2007 {
2008         INIT_LIST_HEAD(&p->list);
2009         p->parent = parent ? parent : &sysctl_table_root.default_set;
2010         p->is_seen = is_seen;
2011 }
2012
2013 #else /* !CONFIG_SYSCTL */
2014 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2015 {
2016         return NULL;
2017 }
2018
2019 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2020                                                     struct ctl_table *table)
2021 {
2022         return NULL;
2023 }
2024
2025 void unregister_sysctl_table(struct ctl_table_header * table)
2026 {
2027 }
2028
2029 void setup_sysctl_set(struct ctl_table_set *p,
2030         struct ctl_table_set *parent,
2031         int (*is_seen)(struct ctl_table_set *))
2032 {
2033 }
2034
2035 void sysctl_head_put(struct ctl_table_header *head)
2036 {
2037 }
2038
2039 #endif /* CONFIG_SYSCTL */
2040
2041 /*
2042  * /proc/sys support
2043  */
2044
2045 #ifdef CONFIG_PROC_SYSCTL
2046
2047 static int _proc_do_string(void* data, int maxlen, int write,
2048                            void __user *buffer,
2049                            size_t *lenp, loff_t *ppos)
2050 {
2051         size_t len;
2052         char __user *p;
2053         char c;
2054
2055         if (!data || !maxlen || !*lenp) {
2056                 *lenp = 0;
2057                 return 0;
2058         }
2059
2060         if (write) {
2061                 len = 0;
2062                 p = buffer;
2063                 while (len < *lenp) {
2064                         if (get_user(c, p++))
2065                                 return -EFAULT;
2066                         if (c == 0 || c == '\n')
2067                                 break;
2068                         len++;
2069                 }
2070                 if (len >= maxlen)
2071                         len = maxlen-1;
2072                 if(copy_from_user(data, buffer, len))
2073                         return -EFAULT;
2074                 ((char *) data)[len] = 0;
2075                 *ppos += *lenp;
2076         } else {
2077                 len = strlen(data);
2078                 if (len > maxlen)
2079                         len = maxlen;
2080
2081                 if (*ppos > len) {
2082                         *lenp = 0;
2083                         return 0;
2084                 }
2085
2086                 data += *ppos;
2087                 len  -= *ppos;
2088
2089                 if (len > *lenp)
2090                         len = *lenp;
2091                 if (len)
2092                         if(copy_to_user(buffer, data, len))
2093                                 return -EFAULT;
2094                 if (len < *lenp) {
2095                         if(put_user('\n', ((char __user *) buffer) + len))
2096                                 return -EFAULT;
2097                         len++;
2098                 }
2099                 *lenp = len;
2100                 *ppos += len;
2101         }
2102         return 0;
2103 }
2104
2105 /**
2106  * proc_dostring - read a string sysctl
2107  * @table: the sysctl table
2108  * @write: %TRUE if this is a write to the sysctl file
2109  * @buffer: the user buffer
2110  * @lenp: the size of the user buffer
2111  * @ppos: file position
2112  *
2113  * Reads/writes a string from/to the user buffer. If the kernel
2114  * buffer provided is not large enough to hold the string, the
2115  * string is truncated. The copied string is %NULL-terminated.
2116  * If the string is being read by the user process, it is copied
2117  * and a newline '\n' is added. It is truncated if the buffer is
2118  * not large enough.
2119  *
2120  * Returns 0 on success.
2121  */
2122 int proc_dostring(struct ctl_table *table, int write,
2123                   void __user *buffer, size_t *lenp, loff_t *ppos)
2124 {
2125         return _proc_do_string(table->data, table->maxlen, write,
2126                                buffer, lenp, ppos);
2127 }
2128
2129 static size_t proc_skip_spaces(char **buf)
2130 {
2131         size_t ret;
2132         char *tmp = skip_spaces(*buf);
2133         ret = tmp - *buf;
2134         *buf = tmp;
2135         return ret;
2136 }
2137
2138 static void proc_skip_char(char **buf, size_t *size, const char v)
2139 {
2140         while (*size) {
2141                 if (**buf != v)
2142                         break;
2143                 (*size)--;
2144                 (*buf)++;
2145         }
2146 }
2147
2148 #define TMPBUFLEN 22
2149 /**
2150  * proc_get_long - reads an ASCII formatted integer from a user buffer
2151  *
2152  * @buf: a kernel buffer
2153  * @size: size of the kernel buffer
2154  * @val: this is where the number will be stored
2155  * @neg: set to %TRUE if number is negative
2156  * @perm_tr: a vector which contains the allowed trailers
2157  * @perm_tr_len: size of the perm_tr vector
2158  * @tr: pointer to store the trailer character
2159  *
2160  * In case of success %0 is returned and @buf and @size are updated with
2161  * the amount of bytes read. If @tr is non-NULL and a trailing
2162  * character exists (size is non-zero after returning from this
2163  * function), @tr is updated with the trailing character.
2164  */
2165 static int proc_get_long(char **buf, size_t *size,
2166                           unsigned long *val, bool *neg,
2167                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2168 {
2169         int len;
2170         char *p, tmp[TMPBUFLEN];
2171
2172         if (!*size)
2173                 return -EINVAL;
2174
2175         len = *size;
2176         if (len > TMPBUFLEN - 1)
2177                 len = TMPBUFLEN - 1;
2178
2179         memcpy(tmp, *buf, len);
2180
2181         tmp[len] = 0;
2182         p = tmp;
2183         if (*p == '-' && *size > 1) {
2184                 *neg = true;
2185                 p++;
2186         } else
2187                 *neg = false;
2188         if (!isdigit(*p))
2189                 return -EINVAL;
2190
2191         *val = simple_strtoul(p, &p, 0);
2192
2193         len = p - tmp;
2194
2195         /* We don't know if the next char is whitespace thus we may accept
2196          * invalid integers (e.g. 1234...a) or two integers instead of one
2197          * (e.g. 123...1). So lets not allow such large numbers. */
2198         if (len == TMPBUFLEN - 1)
2199                 return -EINVAL;
2200
2201         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2202                 return -EINVAL;
2203
2204         if (tr && (len < *size))
2205                 *tr = *p;
2206
2207         *buf += len;
2208         *size -= len;
2209
2210         return 0;
2211 }
2212
2213 /**
2214  * proc_put_long - converts an integer to a decimal ASCII formatted string
2215  *
2216  * @buf: the user buffer
2217  * @size: the size of the user buffer
2218  * @val: the integer to be converted
2219  * @neg: sign of the number, %TRUE for negative
2220  *
2221  * In case of success %0 is returned and @buf and @size are updated with
2222  * the amount of bytes written.
2223  */
2224 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2225                           bool neg)
2226 {
2227         int len;
2228         char tmp[TMPBUFLEN], *p = tmp;
2229
2230         sprintf(p, "%s%lu", neg ? "-" : "", val);
2231         len = strlen(tmp);
2232         if (len > *size)
2233                 len = *size;
2234         if (copy_to_user(*buf, tmp, len))
2235                 return -EFAULT;
2236         *size -= len;
2237         *buf += len;
2238         return 0;
2239 }
2240 #undef TMPBUFLEN
2241
2242 static int proc_put_char(void __user **buf, size_t *size, char c)
2243 {
2244         if (*size) {
2245                 char __user **buffer = (char __user **)buf;
2246                 if (put_user(c, *buffer))
2247                         return -EFAULT;
2248                 (*size)--, (*buffer)++;
2249                 *buf = *buffer;
2250         }
2251         return 0;
2252 }
2253
2254 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2255                                  int *valp,
2256                                  int write, void *data)
2257 {
2258         if (write) {
2259                 *valp = *negp ? -*lvalp : *lvalp;
2260         } else {
2261                 int val = *valp;
2262                 if (val < 0) {
2263                         *negp = true;
2264                         *lvalp = (unsigned long)-val;
2265                 } else {
2266                         *negp = false;
2267                         *lvalp = (unsigned long)val;
2268                 }
2269         }
2270         return 0;
2271 }
2272
2273 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2274
2275 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2276                   int write, void __user *buffer,
2277                   size_t *lenp, loff_t *ppos,
2278                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2279                               int write, void *data),
2280                   void *data)
2281 {
2282         int *i, vleft, first = 1, err = 0;
2283         unsigned long page = 0;
2284         size_t left;
2285         char *kbuf;
2286
2287         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2288                 *lenp = 0;
2289                 return 0;
2290         }
2291
2292         i = (int *) tbl_data;
2293         vleft = table->maxlen / sizeof(*i);
2294         left = *lenp;
2295
2296         if (!conv)
2297                 conv = do_proc_dointvec_conv;
2298
2299         if (write) {
2300                 if (left > PAGE_SIZE - 1)
2301                         left = PAGE_SIZE - 1;
2302                 page = __get_free_page(GFP_TEMPORARY);
2303                 kbuf = (char *) page;
2304                 if (!kbuf)
2305                         return -ENOMEM;
2306                 if (copy_from_user(kbuf, buffer, left)) {
2307                         err = -EFAULT;
2308                         goto free;
2309                 }
2310                 kbuf[left] = 0;
2311         }
2312
2313         for (; left && vleft--; i++, first=0) {
2314                 unsigned long lval;
2315                 bool neg;
2316
2317                 if (write) {
2318                         left -= proc_skip_spaces(&kbuf);
2319
2320                         if (!left)
2321                                 break;
2322                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2323                                              proc_wspace_sep,
2324                                              sizeof(proc_wspace_sep), NULL);
2325                         if (err)
2326                                 break;
2327                         if (conv(&neg, &lval, i, 1, data)) {
2328                                 err = -EINVAL;
2329                                 break;
2330                         }
2331                 } else {
2332                         if (conv(&neg, &lval, i, 0, data)) {
2333                                 err = -EINVAL;
2334                                 break;
2335                         }
2336                         if (!first)
2337                                 err = proc_put_char(&buffer, &left, '\t');
2338                         if (err)
2339                                 break;
2340                         err = proc_put_long(&buffer, &left, lval, neg);
2341                         if (err)
2342                                 break;
2343                 }
2344         }
2345
2346         if (!write && !first && left && !err)
2347                 err = proc_put_char(&buffer, &left, '\n');
2348         if (write && !err && left)
2349                 left -= proc_skip_spaces(&kbuf);
2350 free:
2351         if (write) {
2352                 free_page(page);
2353                 if (first)
2354                         return err ? : -EINVAL;
2355         }
2356         *lenp -= left;
2357         *ppos += *lenp;
2358         return err;
2359 }
2360
2361 static int do_proc_dointvec(struct ctl_table *table, int write,
2362                   void __user *buffer, size_t *lenp, loff_t *ppos,
2363                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2364                               int write, void *data),
2365                   void *data)
2366 {
2367         return __do_proc_dointvec(table->data, table, write,
2368                         buffer, lenp, ppos, conv, data);
2369 }
2370
2371 /**
2372  * proc_dointvec - read a vector of integers
2373  * @table: the sysctl table
2374  * @write: %TRUE if this is a write to the sysctl file
2375  * @buffer: the user buffer
2376  * @lenp: the size of the user buffer
2377  * @ppos: file position
2378  *
2379  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2380  * values from/to the user buffer, treated as an ASCII string.
2381  *
2382  * Returns 0 on success.
2383  */
2384 int proc_dointvec(struct ctl_table *table, int write,
2385                      void __user *buffer, size_t *lenp, loff_t *ppos)
2386 {
2387     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2388                             NULL,NULL);
2389 }
2390
2391 /*
2392  * Taint values can only be increased
2393  * This means we can safely use a temporary.
2394  */
2395 static int proc_taint(struct ctl_table *table, int write,
2396                                void __user *buffer, size_t *lenp, loff_t *ppos)
2397 {
2398         struct ctl_table t;
2399         unsigned long tmptaint = get_taint();
2400         int err;
2401
2402         if (write && !capable(CAP_SYS_ADMIN))
2403                 return -EPERM;
2404
2405         t = *table;
2406         t.data = &tmptaint;
2407         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2408         if (err < 0)
2409                 return err;
2410
2411         if (write) {
2412                 /*
2413                  * Poor man's atomic or. Not worth adding a primitive
2414                  * to everyone's atomic.h for this
2415                  */
2416                 int i;
2417                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2418                         if ((tmptaint >> i) & 1)
2419                                 add_taint(i);
2420                 }
2421         }
2422
2423         return err;
2424 }
2425
2426 #ifdef CONFIG_PRINTK
2427 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2428                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2429 {
2430         if (write && !capable(CAP_SYS_ADMIN))
2431                 return -EPERM;
2432
2433         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2434 }
2435 #endif
2436
2437 struct do_proc_dointvec_minmax_conv_param {
2438         int *min;
2439         int *max;
2440 };
2441
2442 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2443                                         int *valp,
2444                                         int write, void *data)
2445 {
2446         struct do_proc_dointvec_minmax_conv_param *param = data;
2447         if (write) {
2448                 int val = *negp ? -*lvalp : *lvalp;
2449                 if ((param->min && *param->min > val) ||
2450                     (param->max && *param->max < val))
2451                         return -EINVAL;
2452                 *valp = val;
2453         } else {
2454                 int val = *valp;
2455                 if (val < 0) {
2456                         *negp = true;
2457                         *lvalp = (unsigned long)-val;
2458                 } else {
2459                         *negp = false;
2460                         *lvalp = (unsigned long)val;
2461                 }
2462         }
2463         return 0;
2464 }
2465
2466 /**
2467  * proc_dointvec_minmax - read a vector of integers with min/max values
2468  * @table: the sysctl table
2469  * @write: %TRUE if this is a write to the sysctl file
2470  * @buffer: the user buffer
2471  * @lenp: the size of the user buffer
2472  * @ppos: file position
2473  *
2474  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2475  * values from/to the user buffer, treated as an ASCII string.
2476  *
2477  * This routine will ensure the values are within the range specified by
2478  * table->extra1 (min) and table->extra2 (max).
2479  *
2480  * Returns 0 on success.
2481  */
2482 int proc_dointvec_minmax(struct ctl_table *table, int write,
2483                   void __user *buffer, size_t *lenp, loff_t *ppos)
2484 {
2485         struct do_proc_dointvec_minmax_conv_param param = {
2486                 .min = (int *) table->extra1,
2487                 .max = (int *) table->extra2,
2488         };
2489         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2490                                 do_proc_dointvec_minmax_conv, &param);
2491 }
2492
2493 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2494                                      void __user *buffer,
2495                                      size_t *lenp, loff_t *ppos,
2496                                      unsigned long convmul,
2497                                      unsigned long convdiv)
2498 {
2499         unsigned long *i, *min, *max;
2500         int vleft, first = 1, err = 0;
2501         unsigned long page = 0;
2502         size_t left;
2503         char *kbuf;
2504
2505         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2506                 *lenp = 0;
2507                 return 0;
2508         }
2509
2510         i = (unsigned long *) data;
2511         min = (unsigned long *) table->extra1;
2512         max = (unsigned long *) table->extra2;
2513         vleft = table->maxlen / sizeof(unsigned long);
2514         left = *lenp;
2515
2516         if (write) {
2517                 if (left > PAGE_SIZE - 1)
2518                         left = PAGE_SIZE - 1;
2519                 page = __get_free_page(GFP_TEMPORARY);
2520                 kbuf = (char *) page;
2521                 if (!kbuf)
2522                         return -ENOMEM;
2523                 if (copy_from_user(kbuf, buffer, left)) {
2524                         err = -EFAULT;
2525                         goto free;
2526                 }
2527                 kbuf[left] = 0;
2528         }
2529
2530         for (; left && vleft--; i++, first = 0) {
2531                 unsigned long val;
2532
2533                 if (write) {
2534                         bool neg;
2535
2536                         left -= proc_skip_spaces(&kbuf);
2537
2538                         err = proc_get_long(&kbuf, &left, &val, &neg,
2539                                              proc_wspace_sep,
2540                                              sizeof(proc_wspace_sep), NULL);
2541                         if (err)
2542                                 break;
2543                         if (neg)
2544                                 continue;
2545                         if ((min && val < *min) || (max && val > *max))
2546                                 continue;
2547                         *i = val;
2548                 } else {
2549                         val = convdiv * (*i) / convmul;
2550                         if (!first)
2551                                 err = proc_put_char(&buffer, &left, '\t');
2552                         err = proc_put_long(&buffer, &left, val, false);
2553                         if (err)
2554                                 break;
2555                 }
2556         }
2557
2558         if (!write && !first && left && !err)
2559                 err = proc_put_char(&buffer, &left, '\n');
2560         if (write && !err)
2561                 left -= proc_skip_spaces(&kbuf);
2562 free:
2563         if (write) {
2564                 free_page(page);
2565                 if (first)
2566                         return err ? : -EINVAL;
2567         }
2568         *lenp -= left;
2569         *ppos += *lenp;
2570         return err;
2571 }
2572
2573 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2574                                      void __user *buffer,
2575                                      size_t *lenp, loff_t *ppos,
2576                                      unsigned long convmul,
2577                                      unsigned long convdiv)
2578 {
2579         return __do_proc_doulongvec_minmax(table->data, table, write,
2580                         buffer, lenp, ppos, convmul, convdiv);
2581 }
2582
2583 /**
2584  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2585  * @table: the sysctl table
2586  * @write: %TRUE if this is a write to the sysctl file
2587  * @buffer: the user buffer
2588  * @lenp: the size of the user buffer
2589  * @ppos: file position
2590  *
2591  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2592  * values from/to the user buffer, treated as an ASCII string.
2593  *
2594  * This routine will ensure the values are within the range specified by
2595  * table->extra1 (min) and table->extra2 (max).
2596  *
2597  * Returns 0 on success.
2598  */
2599 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2600                            void __user *buffer, size_t *lenp, loff_t *ppos)
2601 {
2602     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2603 }
2604
2605 /**
2606  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2607  * @table: the sysctl table
2608  * @write: %TRUE if this is a write to the sysctl file
2609  * @buffer: the user buffer
2610  * @lenp: the size of the user buffer
2611  * @ppos: file position
2612  *
2613  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2614  * values from/to the user buffer, treated as an ASCII string. The values
2615  * are treated as milliseconds, and converted to jiffies when they are stored.
2616  *
2617  * This routine will ensure the values are within the range specified by
2618  * table->extra1 (min) and table->extra2 (max).
2619  *
2620  * Returns 0 on success.
2621  */
2622 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2623                                       void __user *buffer,
2624                                       size_t *lenp, loff_t *ppos)
2625 {
2626     return do_proc_doulongvec_minmax(table, write, buffer,
2627                                      lenp, ppos, HZ, 1000l);
2628 }
2629
2630
2631 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2632                                          int *valp,
2633                                          int write, void *data)
2634 {
2635         if (write) {
2636                 if (*lvalp > LONG_MAX / HZ)
2637                         return 1;
2638                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2639         } else {
2640                 int val = *valp;
2641                 unsigned long lval;
2642                 if (val < 0) {
2643                         *negp = true;
2644                         lval = (unsigned long)-val;
2645                 } else {
2646                         *negp = false;
2647                         lval = (unsigned long)val;
2648                 }
2649                 *lvalp = lval / HZ;
2650         }
2651         return 0;
2652 }
2653
2654 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2655                                                 int *valp,
2656                                                 int write, void *data)
2657 {
2658         if (write) {
2659                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2660                         return 1;
2661                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2662         } else {
2663                 int val = *valp;
2664                 unsigned long lval;
2665                 if (val < 0) {
2666                         *negp = true;
2667                         lval = (unsigned long)-val;
2668                 } else {
2669                         *negp = false;
2670                         lval = (unsigned long)val;
2671                 }
2672                 *lvalp = jiffies_to_clock_t(lval);
2673         }
2674         return 0;
2675 }
2676
2677 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2678                                             int *valp,
2679                                             int write, void *data)
2680 {
2681         if (write) {
2682                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2683         } else {
2684                 int val = *valp;
2685                 unsigned long lval;
2686                 if (val < 0) {
2687                         *negp = true;
2688                         lval = (unsigned long)-val;
2689                 } else {
2690                         *negp = false;
2691                         lval = (unsigned long)val;
2692                 }
2693                 *lvalp = jiffies_to_msecs(lval);
2694         }
2695         return 0;
2696 }
2697
2698 /**
2699  * proc_dointvec_jiffies - read a vector of integers as seconds
2700  * @table: the sysctl table
2701  * @write: %TRUE if this is a write to the sysctl file
2702  * @buffer: the user buffer
2703  * @lenp: the size of the user buffer
2704  * @ppos: file position
2705  *
2706  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2707  * values from/to the user buffer, treated as an ASCII string.
2708  * The values read are assumed to be in seconds, and are converted into
2709  * jiffies.
2710  *
2711  * Returns 0 on success.
2712  */
2713 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2714                           void __user *buffer, size_t *lenp, loff_t *ppos)
2715 {
2716     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2717                             do_proc_dointvec_jiffies_conv,NULL);
2718 }
2719
2720 /**
2721  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2722  * @table: the sysctl table
2723  * @write: %TRUE if this is a write to the sysctl file
2724  * @buffer: the user buffer
2725  * @lenp: the size of the user buffer
2726  * @ppos: pointer to the file position
2727  *
2728  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2729  * values from/to the user buffer, treated as an ASCII string.
2730  * The values read are assumed to be in 1/USER_HZ seconds, and
2731  * are converted into jiffies.
2732  *
2733  * Returns 0 on success.
2734  */
2735 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2736                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2737 {
2738     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2739                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2740 }
2741
2742 /**
2743  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2744  * @table: the sysctl table
2745  * @write: %TRUE if this is a write to the sysctl file
2746  * @buffer: the user buffer
2747  * @lenp: the size of the user buffer
2748  * @ppos: file position
2749  * @ppos: the current position in the file
2750  *
2751  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2752  * values from/to the user buffer, treated as an ASCII string.
2753  * The values read are assumed to be in 1/1000 seconds, and
2754  * are converted into jiffies.
2755  *
2756  * Returns 0 on success.
2757  */
2758 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2759                              void __user *buffer, size_t *lenp, loff_t *ppos)
2760 {
2761         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2762                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2763 }
2764
2765 static int proc_do_cad_pid(struct ctl_table *table, int write,
2766                            void __user *buffer, size_t *lenp, loff_t *ppos)
2767 {
2768         struct pid *new_pid;
2769         pid_t tmp;
2770         int r;
2771
2772         tmp = pid_vnr(cad_pid);
2773
2774         r = __do_proc_dointvec(&tmp, table, write, buffer,
2775                                lenp, ppos, NULL, NULL);
2776         if (r || !write)
2777                 return r;
2778
2779         new_pid = find_get_pid(tmp);
2780         if (!new_pid)
2781                 return -ESRCH;
2782
2783         put_pid(xchg(&cad_pid, new_pid));
2784         return 0;
2785 }
2786
2787 /**
2788  * proc_do_large_bitmap - read/write from/to a large bitmap
2789  * @table: the sysctl table
2790  * @write: %TRUE if this is a write to the sysctl file
2791  * @buffer: the user buffer
2792  * @lenp: the size of the user buffer
2793  * @ppos: file position
2794  *
2795  * The bitmap is stored at table->data and the bitmap length (in bits)
2796  * in table->maxlen.
2797  *
2798  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2799  * large bitmaps may be represented in a compact manner. Writing into
2800  * the file will clear the bitmap then update it with the given input.
2801  *
2802  * Returns 0 on success.
2803  */
2804 int proc_do_large_bitmap(struct ctl_table *table, int write,
2805                          void __user *buffer, size_t *lenp, loff_t *ppos)
2806 {
2807         int err = 0;
2808         bool first = 1;
2809         size_t left = *lenp;
2810         unsigned long bitmap_len = table->maxlen;
2811         unsigned long *bitmap = (unsigned long *) table->data;
2812         unsigned long *tmp_bitmap = NULL;
2813         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2814
2815         if (!bitmap_len || !left || (*ppos && !write)) {
2816                 *lenp = 0;
2817                 return 0;
2818         }
2819
2820         if (write) {
2821                 unsigned long page = 0;
2822                 char *kbuf;
2823
2824                 if (left > PAGE_SIZE - 1)
2825                         left = PAGE_SIZE - 1;
2826
2827                 page = __get_free_page(GFP_TEMPORARY);
2828                 kbuf = (char *) page;
2829                 if (!kbuf)
2830                         return -ENOMEM;
2831                 if (copy_from_user(kbuf, buffer, left)) {
2832                         free_page(page);
2833                         return -EFAULT;
2834                 }
2835                 kbuf[left] = 0;
2836
2837                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2838                                      GFP_KERNEL);
2839                 if (!tmp_bitmap) {
2840                         free_page(page);
2841                         return -ENOMEM;
2842                 }
2843                 proc_skip_char(&kbuf, &left, '\n');
2844                 while (!err && left) {
2845                         unsigned long val_a, val_b;
2846                         bool neg;
2847
2848                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2849                                              sizeof(tr_a), &c);
2850                         if (err)
2851                                 break;
2852                         if (val_a >= bitmap_len || neg) {
2853                                 err = -EINVAL;
2854                                 break;
2855                         }
2856
2857                         val_b = val_a;
2858                         if (left) {
2859                                 kbuf++;
2860                                 left--;
2861                         }
2862
2863                         if (c == '-') {
2864                                 err = proc_get_long(&kbuf, &left, &val_b,
2865                                                      &neg, tr_b, sizeof(tr_b),
2866                                                      &c);
2867                                 if (err)
2868                                         break;
2869                                 if (val_b >= bitmap_len || neg ||
2870                                     val_a > val_b) {
2871                                         err = -EINVAL;
2872                                         break;
2873                                 }
2874                                 if (left) {
2875                                         kbuf++;
2876                                         left--;
2877                                 }
2878                         }
2879
2880                         while (val_a <= val_b)
2881                                 set_bit(val_a++, tmp_bitmap);
2882
2883                         first = 0;
2884                         proc_skip_char(&kbuf, &left, '\n');
2885                 }
2886                 free_page(page);
2887         } else {
2888                 unsigned long bit_a, bit_b = 0;
2889
2890                 while (left) {
2891                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2892                         if (bit_a >= bitmap_len)
2893                                 break;
2894                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2895                                                    bit_a + 1) - 1;
2896
2897                         if (!first) {
2898                                 err = proc_put_char(&buffer, &left, ',');
2899                                 if (err)
2900                                         break;
2901                         }
2902                         err = proc_put_long(&buffer, &left, bit_a, false);
2903                         if (err)
2904                                 break;
2905                         if (bit_a != bit_b) {
2906                                 err = proc_put_char(&buffer, &left, '-');
2907                                 if (err)
2908                                         break;
2909                                 err = proc_put_long(&buffer, &left, bit_b, false);
2910                                 if (err)
2911                                         break;
2912                         }
2913
2914                         first = 0; bit_b++;
2915                 }
2916                 if (!err)
2917                         err = proc_put_char(&buffer, &left, '\n');
2918         }
2919
2920         if (!err) {
2921                 if (write) {
2922                         if (*ppos)
2923                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2924                         else
2925                                 memcpy(bitmap, tmp_bitmap,
2926                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2927                 }
2928                 kfree(tmp_bitmap);
2929                 *lenp -= left;
2930                 *ppos += *lenp;
2931                 return 0;
2932         } else {
2933                 kfree(tmp_bitmap);
2934                 return err;
2935         }
2936 }
2937
2938 #else /* CONFIG_PROC_SYSCTL */
2939
2940 int proc_dostring(struct ctl_table *table, int write,
2941                   void __user *buffer, size_t *lenp, loff_t *ppos)
2942 {
2943         return -ENOSYS;
2944 }
2945
2946 int proc_dointvec(struct ctl_table *table, int write,
2947                   void __user *buffer, size_t *lenp, loff_t *ppos)
2948 {
2949         return -ENOSYS;
2950 }
2951
2952 int proc_dointvec_minmax(struct ctl_table *table, int write,
2953                     void __user *buffer, size_t *lenp, loff_t *ppos)
2954 {
2955         return -ENOSYS;
2956 }
2957
2958 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2959                     void __user *buffer, size_t *lenp, loff_t *ppos)
2960 {
2961         return -ENOSYS;
2962 }
2963
2964 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2965                     void __user *buffer, size_t *lenp, loff_t *ppos)
2966 {
2967         return -ENOSYS;
2968 }
2969
2970 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2971                              void __user *buffer, size_t *lenp, loff_t *ppos)
2972 {
2973         return -ENOSYS;
2974 }
2975
2976 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2977                     void __user *buffer, size_t *lenp, loff_t *ppos)
2978 {
2979         return -ENOSYS;
2980 }
2981
2982 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2983                                       void __user *buffer,
2984                                       size_t *lenp, loff_t *ppos)
2985 {
2986     return -ENOSYS;
2987 }
2988
2989
2990 #endif /* CONFIG_PROC_SYSCTL */
2991
2992 /*
2993  * No sense putting this after each symbol definition, twice,
2994  * exception granted :-)
2995  */
2996 EXPORT_SYMBOL(proc_dointvec);
2997 EXPORT_SYMBOL(proc_dointvec_jiffies);
2998 EXPORT_SYMBOL(proc_dointvec_minmax);
2999 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3000 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3001 EXPORT_SYMBOL(proc_dostring);
3002 EXPORT_SYMBOL(proc_doulongvec_minmax);
3003 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3004 EXPORT_SYMBOL(register_sysctl_table);
3005 EXPORT_SYMBOL(register_sysctl_paths);
3006 EXPORT_SYMBOL(unregister_sysctl_table);