kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/signal.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/security.h>
  29 #include <linux/ctype.h>
  30 #include <linux/kmemcheck.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/ratelimit.h>
  40 #include <linux/compaction.h>
  41 #include <linux/hugetlb.h>
  42 #include <linux/initrd.h>
  43 #include <linux/key.h>
  44 #include <linux/times.h>
  45 #include <linux/limits.h>
  46 #include <linux/dcache.h>
  47 #include <linux/dnotify.h>
  48 #include <linux/syscalls.h>
  49 #include <linux/vmstat.h>
  50 #include <linux/nfs_fs.h>
  51 #include <linux/acpi.h>
  52 #include <linux/reboot.h>
  53 #include <linux/ftrace.h>
  54 #include <linux/perf_event.h>
  55 #include <linux/kprobes.h>
  56 #include <linux/pipe_fs_i.h>
  57 #include <linux/oom.h>
  58
  59 #include <asm/uaccess.h>
  60 #include <asm/processor.h>
  61
  62 #ifdef CONFIG_X86
  63 #include <asm/nmi.h>
  64 #include <asm/stacktrace.h>
  65 #include <asm/io.h>
  66 #endif
  67 #ifdef CONFIG_BSD_PROCESS_ACCT
  68 #include <linux/acct.h>
  69 #endif
  70 #ifdef CONFIG_RT_MUTEXES
  71 #include <linux/rtmutex.h>
  72 #endif
  73 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  74 #include <linux/lockdep.h>
  75 #endif
  76 #ifdef CONFIG_CHR_DEV_SG
  77 #include <scsi/sg.h>
  78 #endif
  79
  80 #ifdef CONFIG_LOCKUP_DETECTOR
  81 #include <linux/nmi.h>
  82 #endif
  83
  84
  85 #if defined(CONFIG_SYSCTL)
  86
  87 /* External variables not in a header file. */
  88 extern int sysctl_overcommit_memory;
  89 extern int sysctl_overcommit_ratio;
  90 extern int max_threads;
  91 extern int core_uses_pid;
  92 extern int suid_dumpable;
  93 extern char core_pattern[];
  94 extern unsigned int core_pipe_limit;
  95 extern int pid_max;
  96 extern int min_free_kbytes;
  97 extern int pid_max_min, pid_max_max;
  98 extern int sysctl_drop_caches;
  99 extern int percpu_pagelist_fraction;
 100 extern int compat_log;
 101 extern int latencytop_enabled;
 102 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 103 #ifndef CONFIG_MMU
 104 extern int sysctl_nr_trim_pages;
 105 #endif
 106 #ifdef CONFIG_BLOCK
 107 extern int blk_iopoll_enabled;
 108 #endif
 109
 110 /* Constants used for minimum and  maximum */
 111 #ifdef CONFIG_LOCKUP_DETECTOR
 112 static int sixty = 60;
 113 static int neg_one = -1;
 114 #endif
 115
 116 static int zero;
 117 static int __maybe_unused one = 1;
 118 static int __maybe_unused two = 2;
 119 static unsigned long one_ul = 1;
 120 static int one_hundred = 100;
 121 #ifdef CONFIG_PRINTK
 122 static int ten_thousand = 10000;
 123 #endif
 124
 125 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 126 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 127
 128 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 129 static int maxolduid = 65535;
 130 static int minolduid;
 131 static int min_percpu_pagelist_fract = 8;
 132
 133 static int ngroups_max = NGROUPS_MAX;
 134
 135 #ifdef CONFIG_INOTIFY_USER
 136 #include <linux/inotify.h>
 137 #endif
 138 #ifdef CONFIG_SPARC
 139 #include <asm/system.h>
 140 #endif
 141
 142 #ifdef CONFIG_SPARC64
 143 extern int sysctl_tsb_ratio;
 144 #endif
 145
 146 #ifdef __hppa__
 147 extern int pwrsw_enabled;
 148 extern int unaligned_enabled;
 149 #endif
 150
 151 #ifdef CONFIG_S390
 152 #ifdef CONFIG_MATHEMU
 153 extern int sysctl_ieee_emulation_warnings;
 154 #endif
 155 extern int sysctl_userprocess_debug;
 156 extern int spin_retry;
 157 #endif
 158
 159 #ifdef CONFIG_IA64
 160 extern int no_unaligned_warning;
 161 extern int unaligned_dump_stack;
 162 #endif
 163
 164 #ifdef CONFIG_PROC_SYSCTL
 165 static int proc_do_cad_pid(struct ctl_table *table, int write,
 166                   void __user *buffer, size_t *lenp, loff_t *ppos);
 167 static int proc_taint(struct ctl_table *table, int write,
 168                                void __user *buffer, size_t *lenp, loff_t *ppos);
 169 #endif
 170
 171 #ifdef CONFIG_MAGIC_SYSRQ
 172 static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
 173
 174 static int sysrq_sysctl_handler(ctl_table *table, int write,
 175                                 void __user *buffer, size_t *lenp,
 176                                 loff_t *ppos)
 177 {
 178         int error;
 179
 180         error = proc_dointvec(table, write, buffer, lenp, ppos);
 181         if (error)
 182                 return error;
 183
 184         if (write)
 185                 sysrq_toggle_support(__sysrq_enabled);
 186
 187         return 0;
 188 }
 189
 190 #endif
 191
 192 static struct ctl_table root_table[];
 193 static struct ctl_table_root sysctl_table_root;
 194 static struct ctl_table_header root_table_header = {
 195         .count = 1,
 196         .ctl_table = root_table,
 197         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 198         .root = &sysctl_table_root,
 199         .set = &sysctl_table_root.default_set,
 200 };
 201 static struct ctl_table_root sysctl_table_root = {
 202         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 203         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 204 };
 205
 206 static struct ctl_table kern_table[];
 207 static struct ctl_table vm_table[];
 208 static struct ctl_table fs_table[];
 209 static struct ctl_table debug_table[];
 210 static struct ctl_table dev_table[];
 211 extern struct ctl_table random_table[];
 212 #ifdef CONFIG_EPOLL
 213 extern struct ctl_table epoll_table[];
 214 #endif
 215
 216 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 217 int sysctl_legacy_va_layout;
 218 #endif
 219
 220 /* The default sysctl tables: */
 221
 222 static struct ctl_table root_table[] = {
 223         {
 224                 .procname       = "kernel",
 225                 .mode           = 0555,
 226                 .child          = kern_table,
 227         },
 228         {
 229                 .procname       = "vm",
 230                 .mode           = 0555,
 231                 .child          = vm_table,
 232         },
 233         {
 234                 .procname       = "fs",
 235                 .mode           = 0555,
 236                 .child          = fs_table,
 237         },
 238         {
 239                 .procname       = "debug",
 240                 .mode           = 0555,
 241                 .child          = debug_table,
 242         },
 243         {
 244                 .procname       = "dev",
 245                 .mode           = 0555,
 246                 .child          = dev_table,
 247         },
 248 /*
 249  * NOTE: do not add new entries to this table unless you have read
 250  * Documentation/sysctl/ctl_unnumbered.txt
 251  */
 252         { }
 253 };
 254
 255 #ifdef CONFIG_SCHED_DEBUG
 256 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 257 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 258 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 259 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 260 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 261 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 262 #endif
 263
 264 #ifdef CONFIG_COMPACTION
 265 static int min_extfrag_threshold;
 266 static int max_extfrag_threshold = 1000;
 267 #endif
 268
 269 static struct ctl_table kern_table[] = {
 270         {
 271                 .procname       = "sched_child_runs_first",
 272                 .data           = &sysctl_sched_child_runs_first,
 273                 .maxlen         = sizeof(unsigned int),
 274                 .mode           = 0644,
 275                 .proc_handler   = proc_dointvec,
 276         },
 277 #ifdef CONFIG_SCHED_DEBUG
 278         {
 279                 .procname       = "sched_min_granularity_ns",
 280                 .data           = &sysctl_sched_min_granularity,
 281                 .maxlen         = sizeof(unsigned int),
 282                 .mode           = 0644,
 283                 .proc_handler   = sched_proc_update_handler,
 284                 .extra1         = &min_sched_granularity_ns,
 285                 .extra2         = &max_sched_granularity_ns,
 286         },
 287         {
 288                 .procname       = "sched_latency_ns",
 289                 .data           = &sysctl_sched_latency,
 290                 .maxlen         = sizeof(unsigned int),
 291                 .mode           = 0644,
 292                 .proc_handler   = sched_proc_update_handler,
 293                 .extra1         = &min_sched_granularity_ns,
 294                 .extra2         = &max_sched_granularity_ns,
 295         },
 296         {
 297                 .procname       = "sched_wakeup_granularity_ns",
 298                 .data           = &sysctl_sched_wakeup_granularity,
 299                 .maxlen         = sizeof(unsigned int),
 300                 .mode           = 0644,
 301                 .proc_handler   = sched_proc_update_handler,
 302                 .extra1         = &min_wakeup_granularity_ns,
 303                 .extra2         = &max_wakeup_granularity_ns,
 304         },
 305         {
 306                 .procname       = "sched_tunable_scaling",
 307                 .data           = &sysctl_sched_tunable_scaling,
 308                 .maxlen         = sizeof(enum sched_tunable_scaling),
 309                 .mode           = 0644,
 310                 .proc_handler   = sched_proc_update_handler,
 311                 .extra1         = &min_sched_tunable_scaling,
 312                 .extra2         = &max_sched_tunable_scaling,
 313         },
 314         {
 315                 .procname       = "sched_migration_cost",
 316                 .data           = &sysctl_sched_migration_cost,
 317                 .maxlen         = sizeof(unsigned int),
 318                 .mode           = 0644,
 319                 .proc_handler   = proc_dointvec,
 320         },
 321         {
 322                 .procname       = "sched_nr_migrate",
 323                 .data           = &sysctl_sched_nr_migrate,
 324                 .maxlen         = sizeof(unsigned int),
 325                 .mode           = 0644,
 326                 .proc_handler   = proc_dointvec,
 327         },
 328         {
 329                 .procname       = "sched_time_avg",
 330                 .data           = &sysctl_sched_time_avg,
 331                 .maxlen         = sizeof(unsigned int),
 332                 .mode           = 0644,
 333                 .proc_handler   = proc_dointvec,
 334         },
 335         {
 336                 .procname       = "sched_shares_window",
 337                 .data           = &sysctl_sched_shares_window,
 338                 .maxlen         = sizeof(unsigned int),
 339                 .mode           = 0644,
 340                 .proc_handler   = proc_dointvec,
 341         },
 342         {
 343                 .procname       = "timer_migration",
 344                 .data           = &sysctl_timer_migration,
 345                 .maxlen         = sizeof(unsigned int),
 346                 .mode           = 0644,
 347                 .proc_handler   = proc_dointvec_minmax,
 348                 .extra1         = &zero,
 349                 .extra2         = &one,
 350         },
 351 #endif
 352         {
 353                 .procname       = "sched_rt_period_us",
 354                 .data           = &sysctl_sched_rt_period,
 355                 .maxlen         = sizeof(unsigned int),
 356                 .mode           = 0644,
 357                 .proc_handler   = sched_rt_handler,
 358         },
 359         {
 360                 .procname       = "sched_rt_runtime_us",
 361                 .data           = &sysctl_sched_rt_runtime,
 362                 .maxlen         = sizeof(int),
 363                 .mode           = 0644,
 364                 .proc_handler   = sched_rt_handler,
 365         },
 366         {
 367                 .procname       = "sched_compat_yield",
 368                 .data           = &sysctl_sched_compat_yield,
 369                 .maxlen         = sizeof(unsigned int),
 370                 .mode           = 0644,
 371                 .proc_handler   = proc_dointvec,
 372         },
 373 #ifdef CONFIG_SCHED_AUTOGROUP
 374         {
 375                 .procname       = "sched_autogroup_enabled",
 376                 .data           = &sysctl_sched_autogroup_enabled,
 377                 .maxlen         = sizeof(unsigned int),
 378                 .mode           = 0644,
 379                 .proc_handler   = proc_dointvec,
 380                 .extra1         = &zero,
 381                 .extra2         = &one,
 382         },
 383 #endif
 384 #ifdef CONFIG_PROVE_LOCKING
 385         {
 386                 .procname       = "prove_locking",
 387                 .data           = &prove_locking,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = proc_dointvec,
 391         },
 392 #endif
 393 #ifdef CONFIG_LOCK_STAT
 394         {
 395                 .procname       = "lock_stat",
 396                 .data           = &lock_stat,
 397                 .maxlen         = sizeof(int),
 398                 .mode           = 0644,
 399                 .proc_handler   = proc_dointvec,
 400         },
 401 #endif
 402         {
 403                 .procname       = "panic",
 404                 .data           = &panic_timeout,
 405                 .maxlen         = sizeof(int),
 406                 .mode           = 0644,
 407                 .proc_handler   = proc_dointvec,
 408         },
 409         {
 410                 .procname       = "core_uses_pid",
 411                 .data           = &core_uses_pid,
 412                 .maxlen         = sizeof(int),
 413                 .mode           = 0644,
 414                 .proc_handler   = proc_dointvec,
 415         },
 416         {
 417                 .procname       = "core_pattern",
 418                 .data           = core_pattern,
 419                 .maxlen         = CORENAME_MAX_SIZE,
 420                 .mode           = 0644,
 421                 .proc_handler   = proc_dostring,
 422         },
 423         {
 424                 .procname       = "core_pipe_limit",
 425                 .data           = &core_pipe_limit,
 426                 .maxlen         = sizeof(unsigned int),
 427                 .mode           = 0644,
 428                 .proc_handler   = proc_dointvec,
 429         },
 430 #ifdef CONFIG_PROC_SYSCTL
 431         {
 432                 .procname       = "tainted",
 433                 .maxlen         = sizeof(long),
 434                 .mode           = 0644,
 435                 .proc_handler   = proc_taint,
 436         },
 437 #endif
 438 #ifdef CONFIG_LATENCYTOP
 439         {
 440                 .procname       = "latencytop",
 441                 .data           = &latencytop_enabled,
 442                 .maxlen         = sizeof(int),
 443                 .mode           = 0644,
 444                 .proc_handler   = proc_dointvec,
 445         },
 446 #endif
 447 #ifdef CONFIG_BLK_DEV_INITRD
 448         {
 449                 .procname       = "real-root-dev",
 450                 .data           = &real_root_dev,
 451                 .maxlen         = sizeof(int),
 452                 .mode           = 0644,
 453                 .proc_handler   = proc_dointvec,
 454         },
 455 #endif
 456         {
 457                 .procname       = "print-fatal-signals",
 458                 .data           = &print_fatal_signals,
 459                 .maxlen         = sizeof(int),
 460                 .mode           = 0644,
 461                 .proc_handler   = proc_dointvec,
 462         },
 463 #ifdef CONFIG_SPARC
 464         {
 465                 .procname       = "reboot-cmd",
 466                 .data           = reboot_command,
 467                 .maxlen         = 256,
 468                 .mode           = 0644,
 469                 .proc_handler   = proc_dostring,
 470         },
 471         {
 472                 .procname       = "stop-a",
 473                 .data           = &stop_a_enabled,
 474                 .maxlen         = sizeof (int),
 475                 .mode           = 0644,
 476                 .proc_handler   = proc_dointvec,
 477         },
 478         {
 479                 .procname       = "scons-poweroff",
 480                 .data           = &scons_pwroff,
 481                 .maxlen         = sizeof (int),
 482                 .mode           = 0644,
 483                 .proc_handler   = proc_dointvec,
 484         },
 485 #endif
 486 #ifdef CONFIG_SPARC64
 487         {
 488                 .procname       = "tsb-ratio",
 489                 .data           = &sysctl_tsb_ratio,
 490                 .maxlen         = sizeof (int),
 491                 .mode           = 0644,
 492                 .proc_handler   = proc_dointvec,
 493         },
 494 #endif
 495 #ifdef __hppa__
 496         {
 497                 .procname       = "soft-power",
 498                 .data           = &pwrsw_enabled,
 499                 .maxlen         = sizeof (int),
 500                 .mode           = 0644,
 501                 .proc_handler   = proc_dointvec,
 502         },
 503         {
 504                 .procname       = "unaligned-trap",
 505                 .data           = &unaligned_enabled,
 506                 .maxlen         = sizeof (int),
 507                 .mode           = 0644,
 508                 .proc_handler   = proc_dointvec,
 509         },
 510 #endif
 511         {
 512                 .procname       = "ctrl-alt-del",
 513                 .data           = &C_A_D,
 514                 .maxlen         = sizeof(int),
 515                 .mode           = 0644,
 516                 .proc_handler   = proc_dointvec,
 517         },
 518 #ifdef CONFIG_FUNCTION_TRACER
 519         {
 520                 .procname       = "ftrace_enabled",
 521                 .data           = &ftrace_enabled,
 522                 .maxlen         = sizeof(int),
 523                 .mode           = 0644,
 524                 .proc_handler   = ftrace_enable_sysctl,
 525         },
 526 #endif
 527 #ifdef CONFIG_STACK_TRACER
 528         {
 529                 .procname       = "stack_tracer_enabled",
 530                 .data           = &stack_tracer_enabled,
 531                 .maxlen         = sizeof(int),
 532                 .mode           = 0644,
 533                 .proc_handler   = stack_trace_sysctl,
 534         },
 535 #endif
 536 #ifdef CONFIG_TRACING
 537         {
 538                 .procname       = "ftrace_dump_on_oops",
 539                 .data           = &ftrace_dump_on_oops,
 540                 .maxlen         = sizeof(int),
 541                 .mode           = 0644,
 542                 .proc_handler   = proc_dointvec,
 543         },
 544 #endif
 545 #ifdef CONFIG_MODULES
 546         {
 547                 .procname       = "modprobe",
 548                 .data           = &modprobe_path,
 549                 .maxlen         = KMOD_PATH_LEN,
 550                 .mode           = 0644,
 551                 .proc_handler   = proc_dostring,
 552         },
 553         {
 554                 .procname       = "modules_disabled",
 555                 .data           = &modules_disabled,
 556                 .maxlen         = sizeof(int),
 557                 .mode           = 0644,
 558                 /* only handle a transition from default "0" to "1" */
 559                 .proc_handler   = proc_dointvec_minmax,
 560                 .extra1         = &one,
 561                 .extra2         = &one,
 562         },
 563 #endif
 564 #ifdef CONFIG_HOTPLUG
 565         {
 566                 .procname       = "hotplug",
 567                 .data           = &uevent_helper,
 568                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 569                 .mode           = 0644,
 570                 .proc_handler   = proc_dostring,
 571         },
 572 #endif
 573 #ifdef CONFIG_CHR_DEV_SG
 574         {
 575                 .procname       = "sg-big-buff",
 576                 .data           = &sg_big_buff,
 577                 .maxlen         = sizeof (int),
 578                 .mode           = 0444,
 579                 .proc_handler   = proc_dointvec,
 580         },
 581 #endif
 582 #ifdef CONFIG_BSD_PROCESS_ACCT
 583         {
 584                 .procname       = "acct",
 585                 .data           = &acct_parm,
 586                 .maxlen         = 3*sizeof(int),
 587                 .mode           = 0644,
 588                 .proc_handler   = proc_dointvec,
 589         },
 590 #endif
 591 #ifdef CONFIG_MAGIC_SYSRQ
 592         {
 593                 .procname       = "sysrq",
 594                 .data           = &__sysrq_enabled,
 595                 .maxlen         = sizeof (int),
 596                 .mode           = 0644,
 597                 .proc_handler   = sysrq_sysctl_handler,
 598         },
 599 #endif
 600 #ifdef CONFIG_PROC_SYSCTL
 601         {
 602                 .procname       = "cad_pid",
 603                 .data           = NULL,
 604                 .maxlen         = sizeof (int),
 605                 .mode           = 0600,
 606                 .proc_handler   = proc_do_cad_pid,
 607         },
 608 #endif
 609         {
 610                 .procname       = "threads-max",
 611                 .data           = &max_threads,
 612                 .maxlen         = sizeof(int),
 613                 .mode           = 0644,
 614                 .proc_handler   = proc_dointvec,
 615         },
 616         {
 617                 .procname       = "random",
 618                 .mode           = 0555,
 619                 .child          = random_table,
 620         },
 621         {
 622                 .procname       = "overflowuid",
 623                 .data           = &overflowuid,
 624                 .maxlen         = sizeof(int),
 625                 .mode           = 0644,
 626                 .proc_handler   = proc_dointvec_minmax,
 627                 .extra1         = &minolduid,
 628                 .extra2         = &maxolduid,
 629         },
 630         {
 631                 .procname       = "overflowgid",
 632                 .data           = &overflowgid,
 633                 .maxlen         = sizeof(int),
 634                 .mode           = 0644,
 635                 .proc_handler   = proc_dointvec_minmax,
 636                 .extra1         = &minolduid,
 637                 .extra2         = &maxolduid,
 638         },
 639 #ifdef CONFIG_S390
 640 #ifdef CONFIG_MATHEMU
 641         {
 642                 .procname       = "ieee_emulation_warnings",
 643                 .data           = &sysctl_ieee_emulation_warnings,
 644                 .maxlen         = sizeof(int),
 645                 .mode           = 0644,
 646                 .proc_handler   = proc_dointvec,
 647         },
 648 #endif
 649         {
 650                 .procname       = "userprocess_debug",
 651                 .data           = &show_unhandled_signals,
 652                 .maxlen         = sizeof(int),
 653                 .mode           = 0644,
 654                 .proc_handler   = proc_dointvec,
 655         },
 656 #endif
 657         {
 658                 .procname       = "pid_max",
 659                 .data           = &pid_max,
 660                 .maxlen         = sizeof (int),
 661                 .mode           = 0644,
 662                 .proc_handler   = proc_dointvec_minmax,
 663                 .extra1         = &pid_max_min,
 664                 .extra2         = &pid_max_max,
 665         },
 666         {
 667                 .procname       = "panic_on_oops",
 668                 .data           = &panic_on_oops,
 669                 .maxlen         = sizeof(int),
 670                 .mode           = 0644,
 671                 .proc_handler   = proc_dointvec,
 672         },
 673 #if defined CONFIG_PRINTK
 674         {
 675                 .procname       = "printk",
 676                 .data           = &console_loglevel,
 677                 .maxlen         = 4*sizeof(int),
 678                 .mode           = 0644,
 679                 .proc_handler   = proc_dointvec,
 680         },
 681         {
 682                 .procname       = "printk_ratelimit",
 683                 .data           = &printk_ratelimit_state.interval,
 684                 .maxlen         = sizeof(int),
 685                 .mode           = 0644,
 686                 .proc_handler   = proc_dointvec_jiffies,
 687         },
 688         {
 689                 .procname       = "printk_ratelimit_burst",
 690                 .data           = &printk_ratelimit_state.burst,
 691                 .maxlen         = sizeof(int),
 692                 .mode           = 0644,
 693                 .proc_handler   = proc_dointvec,
 694         },
 695         {
 696                 .procname       = "printk_delay",
 697                 .data           = &printk_delay_msec,
 698                 .maxlen         = sizeof(int),
 699                 .mode           = 0644,
 700                 .proc_handler   = proc_dointvec_minmax,
 701                 .extra1         = &zero,
 702                 .extra2         = &ten_thousand,
 703         },
 704         {
 705                 .procname       = "dmesg_restrict",
 706                 .data           = &dmesg_restrict,
 707                 .maxlen         = sizeof(int),
 708                 .mode           = 0644,
 709                 .proc_handler   = proc_dointvec_minmax,
 710                 .extra1         = &zero,
 711                 .extra2         = &one,
 712         },
 713 #endif
 714         {
 715                 .procname       = "ngroups_max",
 716                 .data           = &ngroups_max,
 717                 .maxlen         = sizeof (int),
 718                 .mode           = 0444,
 719                 .proc_handler   = proc_dointvec,
 720         },
 721 #if defined(CONFIG_LOCKUP_DETECTOR)
 722         {
 723                 .procname       = "watchdog",
 724                 .data           = &watchdog_enabled,
 725                 .maxlen         = sizeof (int),
 726                 .mode           = 0644,
 727                 .proc_handler   = proc_dowatchdog_enabled,
 728         },
 729         {
 730                 .procname       = "watchdog_thresh",
 731                 .data           = &softlockup_thresh,
 732                 .maxlen         = sizeof(int),
 733                 .mode           = 0644,
 734                 .proc_handler   = proc_dowatchdog_thresh,
 735                 .extra1         = &neg_one,
 736                 .extra2         = &sixty,
 737         },
 738         {
 739                 .procname       = "softlockup_panic",
 740                 .data           = &softlockup_panic,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0644,
 743                 .proc_handler   = proc_dointvec_minmax,
 744                 .extra1         = &zero,
 745                 .extra2         = &one,
 746         },
 747         {
 748                 .procname       = "nmi_watchdog",
 749                 .data           = &watchdog_enabled,
 750                 .maxlen         = sizeof (int),
 751                 .mode           = 0644,
 752                 .proc_handler   = proc_dowatchdog_enabled,
 753         },
 754 #endif
 755 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 756         {
 757                 .procname       = "unknown_nmi_panic",
 758                 .data           = &unknown_nmi_panic,
 759                 .maxlen         = sizeof (int),
 760                 .mode           = 0644,
 761                 .proc_handler   = proc_dointvec,
 762         },
 763 #endif
 764 #if defined(CONFIG_X86)
 765         {
 766                 .procname       = "panic_on_unrecovered_nmi",
 767                 .data           = &panic_on_unrecovered_nmi,
 768                 .maxlen         = sizeof(int),
 769                 .mode           = 0644,
 770                 .proc_handler   = proc_dointvec,
 771         },
 772         {
 773                 .procname       = "panic_on_io_nmi",
 774                 .data           = &panic_on_io_nmi,
 775                 .maxlen         = sizeof(int),
 776                 .mode           = 0644,
 777                 .proc_handler   = proc_dointvec,
 778         },
 779         {
 780                 .procname       = "bootloader_type",
 781                 .data           = &bootloader_type,
 782                 .maxlen         = sizeof (int),
 783                 .mode           = 0444,
 784                 .proc_handler   = proc_dointvec,
 785         },
 786         {
 787                 .procname       = "bootloader_version",
 788                 .data           = &bootloader_version,
 789                 .maxlen         = sizeof (int),
 790                 .mode           = 0444,
 791                 .proc_handler   = proc_dointvec,
 792         },
 793         {
 794                 .procname       = "kstack_depth_to_print",
 795                 .data           = &kstack_depth_to_print,
 796                 .maxlen         = sizeof(int),
 797                 .mode           = 0644,
 798                 .proc_handler   = proc_dointvec,
 799         },
 800         {
 801                 .procname       = "io_delay_type",
 802                 .data           = &io_delay_type,
 803                 .maxlen         = sizeof(int),
 804                 .mode           = 0644,
 805                 .proc_handler   = proc_dointvec,
 806         },
 807 #endif
 808 #if defined(CONFIG_MMU)
 809         {
 810                 .procname       = "randomize_va_space",
 811                 .data           = &randomize_va_space,
 812                 .maxlen         = sizeof(int),
 813                 .mode           = 0644,
 814                 .proc_handler   = proc_dointvec,
 815         },
 816 #endif
 817 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 818         {
 819                 .procname       = "spin_retry",
 820                 .data           = &spin_retry,
 821                 .maxlen         = sizeof (int),
 822                 .mode           = 0644,
 823                 .proc_handler   = proc_dointvec,
 824         },
 825 #endif
 826 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 827         {
 828                 .procname       = "acpi_video_flags",
 829                 .data           = &acpi_realmode_flags,
 830                 .maxlen         = sizeof (unsigned long),
 831                 .mode           = 0644,
 832                 .proc_handler   = proc_doulongvec_minmax,
 833         },
 834 #endif
 835 #ifdef CONFIG_IA64
 836         {
 837                 .procname       = "ignore-unaligned-usertrap",
 838                 .data           = &no_unaligned_warning,
 839                 .maxlen         = sizeof (int),
 840                 .mode           = 0644,
 841                 .proc_handler   = proc_dointvec,
 842         },
 843         {
 844                 .procname       = "unaligned-dump-stack",
 845                 .data           = &unaligned_dump_stack,
 846                 .maxlen         = sizeof (int),
 847                 .mode           = 0644,
 848                 .proc_handler   = proc_dointvec,
 849         },
 850 #endif
 851 #ifdef CONFIG_DETECT_HUNG_TASK
 852         {
 853                 .procname       = "hung_task_panic",
 854                 .data           = &sysctl_hung_task_panic,
 855                 .maxlen         = sizeof(int),
 856                 .mode           = 0644,
 857                 .proc_handler   = proc_dointvec_minmax,
 858                 .extra1         = &zero,
 859                 .extra2         = &one,
 860         },
 861         {
 862                 .procname       = "hung_task_check_count",
 863                 .data           = &sysctl_hung_task_check_count,
 864                 .maxlen         = sizeof(unsigned long),
 865                 .mode           = 0644,
 866                 .proc_handler   = proc_doulongvec_minmax,
 867         },
 868         {
 869                 .procname       = "hung_task_timeout_secs",
 870                 .data           = &sysctl_hung_task_timeout_secs,
 871                 .maxlen         = sizeof(unsigned long),
 872                 .mode           = 0644,
 873                 .proc_handler   = proc_dohung_task_timeout_secs,
 874         },
 875         {
 876                 .procname       = "hung_task_warnings",
 877                 .data           = &sysctl_hung_task_warnings,
 878                 .maxlen         = sizeof(unsigned long),
 879                 .mode           = 0644,
 880                 .proc_handler   = proc_doulongvec_minmax,
 881         },
 882 #endif
 883 #ifdef CONFIG_COMPAT
 884         {
 885                 .procname       = "compat-log",
 886                 .data           = &compat_log,
 887                 .maxlen         = sizeof (int),
 888                 .mode           = 0644,
 889                 .proc_handler   = proc_dointvec,
 890         },
 891 #endif
 892 #ifdef CONFIG_RT_MUTEXES
 893         {
 894                 .procname       = "max_lock_depth",
 895                 .data           = &max_lock_depth,
 896                 .maxlen         = sizeof(int),
 897                 .mode           = 0644,
 898                 .proc_handler   = proc_dointvec,
 899         },
 900 #endif
 901         {
 902                 .procname       = "poweroff_cmd",
 903                 .data           = &poweroff_cmd,
 904                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 905                 .mode           = 0644,
 906                 .proc_handler   = proc_dostring,
 907         },
 908 #ifdef CONFIG_KEYS
 909         {
 910                 .procname       = "keys",
 911                 .mode           = 0555,
 912                 .child          = key_sysctls,
 913         },
 914 #endif
 915 #ifdef CONFIG_RCU_TORTURE_TEST
 916         {
 917                 .procname       = "rcutorture_runnable",
 918                 .data           = &rcutorture_runnable,
 919                 .maxlen         = sizeof(int),
 920                 .mode           = 0644,
 921                 .proc_handler   = proc_dointvec,
 922         },
 923 #endif
 924 #ifdef CONFIG_PERF_EVENTS
 925         {
 926                 .procname       = "perf_event_paranoid",
 927                 .data           = &sysctl_perf_event_paranoid,
 928                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 929                 .mode           = 0644,
 930                 .proc_handler   = proc_dointvec,
 931         },
 932         {
 933                 .procname       = "perf_event_mlock_kb",
 934                 .data           = &sysctl_perf_event_mlock,
 935                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 936                 .mode           = 0644,
 937                 .proc_handler   = proc_dointvec,
 938         },
 939         {
 940                 .procname       = "perf_event_max_sample_rate",
 941                 .data           = &sysctl_perf_event_sample_rate,
 942                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 943                 .mode           = 0644,
 944                 .proc_handler   = proc_dointvec,
 945         },
 946 #endif
 947 #ifdef CONFIG_KMEMCHECK
 948         {
 949                 .procname       = "kmemcheck",
 950                 .data           = &kmemcheck_enabled,
 951                 .maxlen         = sizeof(int),
 952                 .mode           = 0644,
 953                 .proc_handler   = proc_dointvec,
 954         },
 955 #endif
 956 #ifdef CONFIG_BLOCK
 957         {
 958                 .procname       = "blk_iopoll",
 959                 .data           = &blk_iopoll_enabled,
 960                 .maxlen         = sizeof(int),
 961                 .mode           = 0644,
 962                 .proc_handler   = proc_dointvec,
 963         },
 964 #endif
 965 /*
 966  * NOTE: do not add new entries to this table unless you have read
 967  * Documentation/sysctl/ctl_unnumbered.txt
 968  */
 969         { }
 970 };
 971
 972 static struct ctl_table vm_table[] = {
 973         {
 974                 .procname       = "overcommit_memory",
 975                 .data           = &sysctl_overcommit_memory,
 976                 .maxlen         = sizeof(sysctl_overcommit_memory),
 977                 .mode           = 0644,
 978                 .proc_handler   = proc_dointvec,
 979         },
 980         {
 981                 .procname       = "panic_on_oom",
 982                 .data           = &sysctl_panic_on_oom,
 983                 .maxlen         = sizeof(sysctl_panic_on_oom),
 984                 .mode           = 0644,
 985                 .proc_handler   = proc_dointvec,
 986         },
 987         {
 988                 .procname       = "oom_kill_allocating_task",
 989                 .data           = &sysctl_oom_kill_allocating_task,
 990                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 991                 .mode           = 0644,
 992                 .proc_handler   = proc_dointvec,
 993         },
 994         {
 995                 .procname       = "oom_dump_tasks",
 996                 .data           = &sysctl_oom_dump_tasks,
 997                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 998                 .mode           = 0644,
 999                 .proc_handler   = proc_dointvec,
1000         },
1001         {
1002                 .procname       = "overcommit_ratio",
1003                 .data           = &sysctl_overcommit_ratio,
1004                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1005                 .mode           = 0644,
1006                 .proc_handler   = proc_dointvec,
1007         },
1008         {
1009                 .procname       = "page-cluster",
1010                 .data           = &page_cluster,
1011                 .maxlen         = sizeof(int),
1012                 .mode           = 0644,
1013                 .proc_handler   = proc_dointvec,
1014         },
1015         {
1016                 .procname       = "dirty_background_ratio",
1017                 .data           = &dirty_background_ratio,
1018                 .maxlen         = sizeof(dirty_background_ratio),
1019                 .mode           = 0644,
1020                 .proc_handler   = dirty_background_ratio_handler,
1021                 .extra1         = &zero,
1022                 .extra2         = &one_hundred,
1023         },
1024         {
1025                 .procname       = "dirty_background_bytes",
1026                 .data           = &dirty_background_bytes,
1027                 .maxlen         = sizeof(dirty_background_bytes),
1028                 .mode           = 0644,
1029                 .proc_handler   = dirty_background_bytes_handler,
1030                 .extra1         = &one_ul,
1031         },
1032         {
1033                 .procname       = "dirty_ratio",
1034                 .data           = &vm_dirty_ratio,
1035                 .maxlen         = sizeof(vm_dirty_ratio),
1036                 .mode           = 0644,
1037                 .proc_handler   = dirty_ratio_handler,
1038                 .extra1         = &zero,
1039                 .extra2         = &one_hundred,
1040         },
1041         {
1042                 .procname       = "dirty_bytes",
1043                 .data           = &vm_dirty_bytes,
1044                 .maxlen         = sizeof(vm_dirty_bytes),
1045                 .mode           = 0644,
1046                 .proc_handler   = dirty_bytes_handler,
1047                 .extra1         = &dirty_bytes_min,
1048         },
1049         {
1050                 .procname       = "dirty_writeback_centisecs",
1051                 .data           = &dirty_writeback_interval,
1052                 .maxlen         = sizeof(dirty_writeback_interval),
1053                 .mode           = 0644,
1054                 .proc_handler   = dirty_writeback_centisecs_handler,
1055         },
1056         {
1057                 .procname       = "dirty_expire_centisecs",
1058                 .data           = &dirty_expire_interval,
1059                 .maxlen         = sizeof(dirty_expire_interval),
1060                 .mode           = 0644,
1061                 .proc_handler   = proc_dointvec,
1062         },
1063         {
1064                 .procname       = "nr_pdflush_threads",
1065                 .data           = &nr_pdflush_threads,
1066                 .maxlen         = sizeof nr_pdflush_threads,
1067                 .mode           = 0444 /* read-only*/,
1068                 .proc_handler   = proc_dointvec,
1069         },
1070         {
1071                 .procname       = "swappiness",
1072                 .data           = &vm_swappiness,
1073                 .maxlen         = sizeof(vm_swappiness),
1074                 .mode           = 0644,
1075                 .proc_handler   = proc_dointvec_minmax,
1076                 .extra1         = &zero,
1077                 .extra2         = &one_hundred,
1078         },
1079 #ifdef CONFIG_HUGETLB_PAGE
1080         {
1081                 .procname       = "nr_hugepages",
1082                 .data           = NULL,
1083                 .maxlen         = sizeof(unsigned long),
1084                 .mode           = 0644,
1085                 .proc_handler   = hugetlb_sysctl_handler,
1086                 .extra1         = (void *)&hugetlb_zero,
1087                 .extra2         = (void *)&hugetlb_infinity,
1088         },
1089 #ifdef CONFIG_NUMA
1090         {
1091                 .procname       = "nr_hugepages_mempolicy",
1092                 .data           = NULL,
1093                 .maxlen         = sizeof(unsigned long),
1094                 .mode           = 0644,
1095                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1096                 .extra1         = (void *)&hugetlb_zero,
1097                 .extra2         = (void *)&hugetlb_infinity,
1098         },
1099 #endif
1100          {
1101                 .procname       = "hugetlb_shm_group",
1102                 .data           = &sysctl_hugetlb_shm_group,
1103                 .maxlen         = sizeof(gid_t),
1104                 .mode           = 0644,
1105                 .proc_handler   = proc_dointvec,
1106          },
1107          {
1108                 .procname       = "hugepages_treat_as_movable",
1109                 .data           = &hugepages_treat_as_movable,
1110                 .maxlen         = sizeof(int),
1111                 .mode           = 0644,
1112                 .proc_handler   = hugetlb_treat_movable_handler,
1113         },
1114         {
1115                 .procname       = "nr_overcommit_hugepages",
1116                 .data           = NULL,
1117                 .maxlen         = sizeof(unsigned long),
1118                 .mode           = 0644,
1119                 .proc_handler   = hugetlb_overcommit_handler,
1120                 .extra1         = (void *)&hugetlb_zero,
1121                 .extra2         = (void *)&hugetlb_infinity,
1122         },
1123 #endif
1124         {
1125                 .procname       = "lowmem_reserve_ratio",
1126                 .data           = &sysctl_lowmem_reserve_ratio,
1127                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1128                 .mode           = 0644,
1129                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1130         },
1131         {
1132                 .procname       = "drop_caches",
1133                 .data           = &sysctl_drop_caches,
1134                 .maxlen         = sizeof(int),
1135                 .mode           = 0644,
1136                 .proc_handler   = drop_caches_sysctl_handler,
1137         },
1138 #ifdef CONFIG_COMPACTION
1139         {
1140                 .procname       = "compact_memory",
1141                 .data           = &sysctl_compact_memory,
1142                 .maxlen         = sizeof(int),
1143                 .mode           = 0200,
1144                 .proc_handler   = sysctl_compaction_handler,
1145         },
1146         {
1147                 .procname       = "extfrag_threshold",
1148                 .data           = &sysctl_extfrag_threshold,
1149                 .maxlen         = sizeof(int),
1150                 .mode           = 0644,
1151                 .proc_handler   = sysctl_extfrag_handler,
1152                 .extra1         = &min_extfrag_threshold,
1153                 .extra2         = &max_extfrag_threshold,
1154         },
1155
1156 #endif /* CONFIG_COMPACTION */
1157         {
1158                 .procname       = "min_free_kbytes",
1159                 .data           = &min_free_kbytes,
1160                 .maxlen         = sizeof(min_free_kbytes),
1161                 .mode           = 0644,
1162                 .proc_handler   = min_free_kbytes_sysctl_handler,
1163                 .extra1         = &zero,
1164         },
1165         {
1166                 .procname       = "percpu_pagelist_fraction",
1167                 .data           = &percpu_pagelist_fraction,
1168                 .maxlen         = sizeof(percpu_pagelist_fraction),
1169                 .mode           = 0644,
1170                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1171                 .extra1         = &min_percpu_pagelist_fract,
1172         },
1173 #ifdef CONFIG_MMU
1174         {
1175                 .procname       = "max_map_count",
1176                 .data           = &sysctl_max_map_count,
1177                 .maxlen         = sizeof(sysctl_max_map_count),
1178                 .mode           = 0644,
1179                 .proc_handler   = proc_dointvec_minmax,
1180                 .extra1         = &zero,
1181         },
1182 #else
1183         {
1184                 .procname       = "nr_trim_pages",
1185                 .data           = &sysctl_nr_trim_pages,
1186                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1187                 .mode           = 0644,
1188                 .proc_handler   = proc_dointvec_minmax,
1189                 .extra1         = &zero,
1190         },
1191 #endif
1192         {
1193                 .procname       = "laptop_mode",
1194                 .data           = &laptop_mode,
1195                 .maxlen         = sizeof(laptop_mode),
1196                 .mode           = 0644,
1197                 .proc_handler   = proc_dointvec_jiffies,
1198         },
1199         {
1200                 .procname       = "block_dump",
1201                 .data           = &block_dump,
1202                 .maxlen         = sizeof(block_dump),
1203                 .mode           = 0644,
1204                 .proc_handler   = proc_dointvec,
1205                 .extra1         = &zero,
1206         },
1207         {
1208                 .procname       = "vfs_cache_pressure",
1209                 .data           = &sysctl_vfs_cache_pressure,
1210                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1211                 .mode           = 0644,
1212                 .proc_handler   = proc_dointvec,
1213                 .extra1         = &zero,
1214         },
1215 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1216         {
1217                 .procname       = "legacy_va_layout",
1218                 .data           = &sysctl_legacy_va_layout,
1219                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1220                 .mode           = 0644,
1221                 .proc_handler   = proc_dointvec,
1222                 .extra1         = &zero,
1223         },
1224 #endif
1225 #ifdef CONFIG_NUMA
1226         {
1227                 .procname       = "zone_reclaim_mode",
1228                 .data           = &zone_reclaim_mode,
1229                 .maxlen         = sizeof(zone_reclaim_mode),
1230                 .mode           = 0644,
1231                 .proc_handler   = proc_dointvec,
1232                 .extra1         = &zero,
1233         },
1234         {
1235                 .procname       = "min_unmapped_ratio",
1236                 .data           = &sysctl_min_unmapped_ratio,
1237                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1238                 .mode           = 0644,
1239                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1240                 .extra1         = &zero,
1241                 .extra2         = &one_hundred,
1242         },
1243         {
1244                 .procname       = "min_slab_ratio",
1245                 .data           = &sysctl_min_slab_ratio,
1246                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1247                 .mode           = 0644,
1248                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1249                 .extra1         = &zero,
1250                 .extra2         = &one_hundred,
1251         },
1252 #endif
1253 #ifdef CONFIG_SMP
1254         {
1255                 .procname       = "stat_interval",
1256                 .data           = &sysctl_stat_interval,
1257                 .maxlen         = sizeof(sysctl_stat_interval),
1258                 .mode           = 0644,
1259                 .proc_handler   = proc_dointvec_jiffies,
1260         },
1261 #endif
1262 #ifdef CONFIG_MMU
1263         {
1264                 .procname       = "mmap_min_addr",
1265                 .data           = &dac_mmap_min_addr,
1266                 .maxlen         = sizeof(unsigned long),
1267                 .mode           = 0644,
1268                 .proc_handler   = mmap_min_addr_handler,
1269         },
1270 #endif
1271 #ifdef CONFIG_NUMA
1272         {
1273                 .procname       = "numa_zonelist_order",
1274                 .data           = &numa_zonelist_order,
1275                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1276                 .mode           = 0644,
1277                 .proc_handler   = numa_zonelist_order_handler,
1278         },
1279 #endif
1280 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1281    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1282         {
1283                 .procname       = "vdso_enabled",
1284                 .data           = &vdso_enabled,
1285                 .maxlen         = sizeof(vdso_enabled),
1286                 .mode           = 0644,
1287                 .proc_handler   = proc_dointvec,
1288                 .extra1         = &zero,
1289         },
1290 #endif
1291 #ifdef CONFIG_HIGHMEM
1292         {
1293                 .procname       = "highmem_is_dirtyable",
1294                 .data           = &vm_highmem_is_dirtyable,
1295                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1296                 .mode           = 0644,
1297                 .proc_handler   = proc_dointvec_minmax,
1298                 .extra1         = &zero,
1299                 .extra2         = &one,
1300         },
1301 #endif
1302         {
1303                 .procname       = "scan_unevictable_pages",
1304                 .data           = &scan_unevictable_pages,
1305                 .maxlen         = sizeof(scan_unevictable_pages),
1306                 .mode           = 0644,
1307                 .proc_handler   = scan_unevictable_handler,
1308         },
1309 #ifdef CONFIG_MEMORY_FAILURE
1310         {
1311                 .procname       = "memory_failure_early_kill",
1312                 .data           = &sysctl_memory_failure_early_kill,
1313                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1314                 .mode           = 0644,
1315                 .proc_handler   = proc_dointvec_minmax,
1316                 .extra1         = &zero,
1317                 .extra2         = &one,
1318         },
1319         {
1320                 .procname       = "memory_failure_recovery",
1321                 .data           = &sysctl_memory_failure_recovery,
1322                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1323                 .mode           = 0644,
1324                 .proc_handler   = proc_dointvec_minmax,
1325                 .extra1         = &zero,
1326                 .extra2         = &one,
1327         },
1328 #endif
1329
1330 /*
1331  * NOTE: do not add new entries to this table unless you have read
1332  * Documentation/sysctl/ctl_unnumbered.txt
1333  */
1334         { }
1335 };
1336
1337 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1338 static struct ctl_table binfmt_misc_table[] = {
1339         { }
1340 };
1341 #endif
1342
1343 static struct ctl_table fs_table[] = {
1344         {
1345                 .procname       = "inode-nr",
1346                 .data           = &inodes_stat,
1347                 .maxlen         = 2*sizeof(int),
1348                 .mode           = 0444,
1349                 .proc_handler   = proc_nr_inodes,
1350         },
1351         {
1352                 .procname       = "inode-state",
1353                 .data           = &inodes_stat,
1354                 .maxlen         = 7*sizeof(int),
1355                 .mode           = 0444,
1356                 .proc_handler   = proc_nr_inodes,
1357         },
1358         {
1359                 .procname       = "file-nr",
1360                 .data           = &files_stat,
1361                 .maxlen         = sizeof(files_stat),
1362                 .mode           = 0444,
1363                 .proc_handler   = proc_nr_files,
1364         },
1365         {
1366                 .procname       = "file-max",
1367                 .data           = &files_stat.max_files,
1368                 .maxlen         = sizeof(files_stat.max_files),
1369                 .mode           = 0644,
1370                 .proc_handler   = proc_doulongvec_minmax,
1371         },
1372         {
1373                 .procname       = "nr_open",
1374                 .data           = &sysctl_nr_open,
1375                 .maxlen         = sizeof(int),
1376                 .mode           = 0644,
1377                 .proc_handler   = proc_dointvec_minmax,
1378                 .extra1         = &sysctl_nr_open_min,
1379                 .extra2         = &sysctl_nr_open_max,
1380         },
1381         {
1382                 .procname       = "dentry-state",
1383                 .data           = &dentry_stat,
1384                 .maxlen         = 6*sizeof(int),
1385                 .mode           = 0444,
1386                 .proc_handler   = proc_nr_dentry,
1387         },
1388         {
1389                 .procname       = "overflowuid",
1390                 .data           = &fs_overflowuid,
1391                 .maxlen         = sizeof(int),
1392                 .mode           = 0644,
1393                 .proc_handler   = proc_dointvec_minmax,
1394                 .extra1         = &minolduid,
1395                 .extra2         = &maxolduid,
1396         },
1397         {
1398                 .procname       = "overflowgid",
1399                 .data           = &fs_overflowgid,
1400                 .maxlen         = sizeof(int),
1401                 .mode           = 0644,
1402                 .proc_handler   = proc_dointvec_minmax,
1403                 .extra1         = &minolduid,
1404                 .extra2         = &maxolduid,
1405         },
1406 #ifdef CONFIG_FILE_LOCKING
1407         {
1408                 .procname       = "leases-enable",
1409                 .data           = &leases_enable,
1410                 .maxlen         = sizeof(int),
1411                 .mode           = 0644,
1412                 .proc_handler   = proc_dointvec,
1413         },
1414 #endif
1415 #ifdef CONFIG_DNOTIFY
1416         {
1417                 .procname       = "dir-notify-enable",
1418                 .data           = &dir_notify_enable,
1419                 .maxlen         = sizeof(int),
1420                 .mode           = 0644,
1421                 .proc_handler   = proc_dointvec,
1422         },
1423 #endif
1424 #ifdef CONFIG_MMU
1425 #ifdef CONFIG_FILE_LOCKING
1426         {
1427                 .procname       = "lease-break-time",
1428                 .data           = &lease_break_time,
1429                 .maxlen         = sizeof(int),
1430                 .mode           = 0644,
1431                 .proc_handler   = proc_dointvec,
1432         },
1433 #endif
1434 #ifdef CONFIG_AIO
1435         {
1436                 .procname       = "aio-nr",
1437                 .data           = &aio_nr,
1438                 .maxlen         = sizeof(aio_nr),
1439                 .mode           = 0444,
1440                 .proc_handler   = proc_doulongvec_minmax,
1441         },
1442         {
1443                 .procname       = "aio-max-nr",
1444                 .data           = &aio_max_nr,
1445                 .maxlen         = sizeof(aio_max_nr),
1446                 .mode           = 0644,
1447                 .proc_handler   = proc_doulongvec_minmax,
1448         },
1449 #endif /* CONFIG_AIO */
1450 #ifdef CONFIG_INOTIFY_USER
1451         {
1452                 .procname       = "inotify",
1453                 .mode           = 0555,
1454                 .child          = inotify_table,
1455         },
1456 #endif
1457 #ifdef CONFIG_EPOLL
1458         {
1459                 .procname       = "epoll",
1460                 .mode           = 0555,
1461                 .child          = epoll_table,
1462         },
1463 #endif
1464 #endif
1465         {
1466                 .procname       = "suid_dumpable",
1467                 .data           = &suid_dumpable,
1468                 .maxlen         = sizeof(int),
1469                 .mode           = 0644,
1470                 .proc_handler   = proc_dointvec_minmax,
1471                 .extra1         = &zero,
1472                 .extra2         = &two,
1473         },
1474 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1475         {
1476                 .procname       = "binfmt_misc",
1477                 .mode           = 0555,
1478                 .child          = binfmt_misc_table,
1479         },
1480 #endif
1481         {
1482                 .procname       = "pipe-max-size",
1483                 .data           = &pipe_max_size,
1484                 .maxlen         = sizeof(int),
1485                 .mode           = 0644,
1486                 .proc_handler   = &pipe_proc_fn,
1487                 .extra1         = &pipe_min_size,
1488         },
1489 /*
1490  * NOTE: do not add new entries to this table unless you have read
1491  * Documentation/sysctl/ctl_unnumbered.txt
1492  */
1493         { }
1494 };
1495
1496 static struct ctl_table debug_table[] = {
1497 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1498     defined(CONFIG_S390)
1499         {
1500                 .procname       = "exception-trace",
1501                 .data           = &show_unhandled_signals,
1502                 .maxlen         = sizeof(int),
1503                 .mode           = 0644,
1504                 .proc_handler   = proc_dointvec
1505         },
1506 #endif
1507 #if defined(CONFIG_OPTPROBES)
1508         {
1509                 .procname       = "kprobes-optimization",
1510                 .data           = &sysctl_kprobes_optimization,
1511                 .maxlen         = sizeof(int),
1512                 .mode           = 0644,
1513                 .proc_handler   = proc_kprobes_optimization_handler,
1514                 .extra1         = &zero,
1515                 .extra2         = &one,
1516         },
1517 #endif
1518         { }
1519 };
1520
1521 static struct ctl_table dev_table[] = {
1522         { }
1523 };
1524
1525 static DEFINE_SPINLOCK(sysctl_lock);
1526
1527 /* called under sysctl_lock */
1528 static int use_table(struct ctl_table_header *p)
1529 {
1530         if (unlikely(p->unregistering))
1531                 return 0;
1532         p->used++;
1533         return 1;
1534 }
1535
1536 /* called under sysctl_lock */
1537 static void unuse_table(struct ctl_table_header *p)
1538 {
1539         if (!--p->used)
1540                 if (unlikely(p->unregistering))
1541                         complete(p->unregistering);
1542 }
1543
1544 /* called under sysctl_lock, will reacquire if has to wait */
1545 static void start_unregistering(struct ctl_table_header *p)
1546 {
1547         /*
1548          * if p->used is 0, nobody will ever touch that entry again;
1549          * we'll eliminate all paths to it before dropping sysctl_lock
1550          */
1551         if (unlikely(p->used)) {
1552                 struct completion wait;
1553                 init_completion(&wait);
1554                 p->unregistering = &wait;
1555                 spin_unlock(&sysctl_lock);
1556                 wait_for_completion(&wait);
1557                 spin_lock(&sysctl_lock);
1558         } else {
1559                 /* anything non-NULL; we'll never dereference it */
1560                 p->unregistering = ERR_PTR(-EINVAL);
1561         }
1562         /*
1563          * do not remove from the list until nobody holds it; walking the
1564          * list in do_sysctl() relies on that.
1565          */
1566         list_del_init(&p->ctl_entry);
1567 }
1568
1569 void sysctl_head_get(struct ctl_table_header *head)
1570 {
1571         spin_lock(&sysctl_lock);
1572         head->count++;
1573         spin_unlock(&sysctl_lock);
1574 }
1575
1576 void sysctl_head_put(struct ctl_table_header *head)
1577 {
1578         spin_lock(&sysctl_lock);
1579         if (!--head->count)
1580                 kfree(head);
1581         spin_unlock(&sysctl_lock);
1582 }
1583
1584 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1585 {
1586         if (!head)
1587                 BUG();
1588         spin_lock(&sysctl_lock);
1589         if (!use_table(head))
1590                 head = ERR_PTR(-ENOENT);
1591         spin_unlock(&sysctl_lock);
1592         return head;
1593 }
1594
1595 void sysctl_head_finish(struct ctl_table_header *head)
1596 {
1597         if (!head)
1598                 return;
1599         spin_lock(&sysctl_lock);
1600         unuse_table(head);
1601         spin_unlock(&sysctl_lock);
1602 }
1603
1604 static struct ctl_table_set *
1605 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1606 {
1607         struct ctl_table_set *set = &root->default_set;
1608         if (root->lookup)
1609                 set = root->lookup(root, namespaces);
1610         return set;
1611 }
1612
1613 static struct list_head *
1614 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1615 {
1616         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1617         return &set->list;
1618 }
1619
1620 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1621                                             struct ctl_table_header *prev)
1622 {
1623         struct ctl_table_root *root;
1624         struct list_head *header_list;
1625         struct ctl_table_header *head;
1626         struct list_head *tmp;
1627
1628         spin_lock(&sysctl_lock);
1629         if (prev) {
1630                 head = prev;
1631                 tmp = &prev->ctl_entry;
1632                 unuse_table(prev);
1633                 goto next;
1634         }
1635         tmp = &root_table_header.ctl_entry;
1636         for (;;) {
1637                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1638
1639                 if (!use_table(head))
1640                         goto next;
1641                 spin_unlock(&sysctl_lock);
1642                 return head;
1643         next:
1644                 root = head->root;
1645                 tmp = tmp->next;
1646                 header_list = lookup_header_list(root, namespaces);
1647                 if (tmp != header_list)
1648                         continue;
1649
1650                 do {
1651                         root = list_entry(root->root_list.next,
1652                                         struct ctl_table_root, root_list);
1653                         if (root == &sysctl_table_root)
1654                                 goto out;
1655                         header_list = lookup_header_list(root, namespaces);
1656                 } while (list_empty(header_list));
1657                 tmp = header_list->next;
1658         }
1659 out:
1660         spin_unlock(&sysctl_lock);
1661         return NULL;
1662 }
1663
1664 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1665 {
1666         return __sysctl_head_next(current->nsproxy, prev);
1667 }
1668
1669 void register_sysctl_root(struct ctl_table_root *root)
1670 {
1671         spin_lock(&sysctl_lock);
1672         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1673         spin_unlock(&sysctl_lock);
1674 }
1675
1676 /*
1677  * sysctl_perm does NOT grant the superuser all rights automatically, because
1678  * some sysctl variables are readonly even to root.
1679  */
1680
1681 static int test_perm(int mode, int op)
1682 {
1683         if (!current_euid())
1684                 mode >>= 6;
1685         else if (in_egroup_p(0))
1686                 mode >>= 3;
1687         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1688                 return 0;
1689         return -EACCES;
1690 }
1691
1692 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1693 {
1694         int error;
1695         int mode;
1696
1697         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1698         if (error)
1699                 return error;
1700
1701         if (root->permissions)
1702                 mode = root->permissions(root, current->nsproxy, table);
1703         else
1704                 mode = table->mode;
1705
1706         return test_perm(mode, op);
1707 }
1708
1709 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1710 {
1711         for (; table->procname; table++) {
1712                 table->parent = parent;
1713                 if (table->child)
1714                         sysctl_set_parent(table, table->child);
1715         }
1716 }
1717
1718 static __init int sysctl_init(void)
1719 {
1720         sysctl_set_parent(NULL, root_table);
1721 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1722         sysctl_check_table(current->nsproxy, root_table);
1723 #endif
1724         return 0;
1725 }
1726
1727 core_initcall(sysctl_init);
1728
1729 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1730                                       struct ctl_table *table)
1731 {
1732         struct ctl_table *p;
1733         const char *s = branch->procname;
1734
1735         /* branch should have named subdirectory as its first element */
1736         if (!s || !branch->child)
1737                 return NULL;
1738
1739         /* ... and nothing else */
1740         if (branch[1].procname)
1741                 return NULL;
1742
1743         /* table should contain subdirectory with the same name */
1744         for (p = table; p->procname; p++) {
1745                 if (!p->child)
1746                         continue;
1747                 if (p->procname && strcmp(p->procname, s) == 0)
1748                         return p;
1749         }
1750         return NULL;
1751 }
1752
1753 /* see if attaching q to p would be an improvement */
1754 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1755 {
1756         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1757         struct ctl_table *next;
1758         int is_better = 0;
1759         int not_in_parent = !p->attached_by;
1760
1761         while ((next = is_branch_in(by, to)) != NULL) {
1762                 if (by == q->attached_by)
1763                         is_better = 1;
1764                 if (to == p->attached_by)
1765                         not_in_parent = 1;
1766                 by = by->child;
1767                 to = next->child;
1768         }
1769
1770         if (is_better && not_in_parent) {
1771                 q->attached_by = by;
1772                 q->attached_to = to;
1773                 q->parent = p;
1774         }
1775 }
1776
1777 /**
1778  * __register_sysctl_paths - register a sysctl hierarchy
1779  * @root: List of sysctl headers to register on
1780  * @namespaces: Data to compute which lists of sysctl entries are visible
1781  * @path: The path to the directory the sysctl table is in.
1782  * @table: the top-level table structure
1783  *
1784  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1785  * array. A completely 0 filled entry terminates the table.
1786  *
1787  * The members of the &struct ctl_table structure are used as follows:
1788  *
1789  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1790  *            enter a sysctl file
1791  *
1792  * data - a pointer to data for use by proc_handler
1793  *
1794  * maxlen - the maximum size in bytes of the data
1795  *
1796  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1797  *
1798  * child - a pointer to the child sysctl table if this entry is a directory, or
1799  *         %NULL.
1800  *
1801  * proc_handler - the text handler routine (described below)
1802  *
1803  * de - for internal use by the sysctl routines
1804  *
1805  * extra1, extra2 - extra pointers usable by the proc handler routines
1806  *
1807  * Leaf nodes in the sysctl tree will be represented by a single file
1808  * under /proc; non-leaf nodes will be represented by directories.
1809  *
1810  * sysctl(2) can automatically manage read and write requests through
1811  * the sysctl table.  The data and maxlen fields of the ctl_table
1812  * struct enable minimal validation of the values being written to be
1813  * performed, and the mode field allows minimal authentication.
1814  *
1815  * There must be a proc_handler routine for any terminal nodes
1816  * mirrored under /proc/sys (non-terminals are handled by a built-in
1817  * directory handler).  Several default handlers are available to
1818  * cover common cases -
1819  *
1820  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1821  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1822  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1823  *
1824  * It is the handler's job to read the input buffer from user memory
1825  * and process it. The handler should return 0 on success.
1826  *
1827  * This routine returns %NULL on a failure to register, and a pointer
1828  * to the table header on success.
1829  */
1830 struct ctl_table_header *__register_sysctl_paths(
1831         struct ctl_table_root *root,
1832         struct nsproxy *namespaces,
1833         const struct ctl_path *path, struct ctl_table *table)
1834 {
1835         struct ctl_table_header *header;
1836         struct ctl_table *new, **prevp;
1837         unsigned int n, npath;
1838         struct ctl_table_set *set;
1839
1840         /* Count the path components */
1841         for (npath = 0; path[npath].procname; ++npath)
1842                 ;
1843
1844         /*
1845          * For each path component, allocate a 2-element ctl_table array.
1846          * The first array element will be filled with the sysctl entry
1847          * for this, the second will be the sentinel (procname == 0).
1848          *
1849          * We allocate everything in one go so that we don't have to
1850          * worry about freeing additional memory in unregister_sysctl_table.
1851          */
1852         header = kzalloc(sizeof(struct ctl_table_header) +
1853                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1854         if (!header)
1855                 return NULL;
1856
1857         new = (struct ctl_table *) (header + 1);
1858
1859         /* Now connect the dots */
1860         prevp = &header->ctl_table;
1861         for (n = 0; n < npath; ++n, ++path) {
1862                 /* Copy the procname */
1863                 new->procname = path->procname;
1864                 new->mode     = 0555;
1865
1866                 *prevp = new;
1867                 prevp = &new->child;
1868
1869                 new += 2;
1870         }
1871         *prevp = table;
1872         header->ctl_table_arg = table;
1873
1874         INIT_LIST_HEAD(&header->ctl_entry);
1875         header->used = 0;
1876         header->unregistering = NULL;
1877         header->root = root;
1878         sysctl_set_parent(NULL, header->ctl_table);
1879         header->count = 1;
1880 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1881         if (sysctl_check_table(namespaces, header->ctl_table)) {
1882                 kfree(header);
1883                 return NULL;
1884         }
1885 #endif
1886         spin_lock(&sysctl_lock);
1887         header->set = lookup_header_set(root, namespaces);
1888         header->attached_by = header->ctl_table;
1889         header->attached_to = root_table;
1890         header->parent = &root_table_header;
1891         for (set = header->set; set; set = set->parent) {
1892                 struct ctl_table_header *p;
1893                 list_for_each_entry(p, &set->list, ctl_entry) {
1894                         if (p->unregistering)
1895                                 continue;
1896                         try_attach(p, header);
1897                 }
1898         }
1899         header->parent->count++;
1900         list_add_tail(&header->ctl_entry, &header->set->list);
1901         spin_unlock(&sysctl_lock);
1902
1903         return header;
1904 }
1905
1906 /**
1907  * register_sysctl_table_path - register a sysctl table hierarchy
1908  * @path: The path to the directory the sysctl table is in.
1909  * @table: the top-level table structure
1910  *
1911  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1912  * array. A completely 0 filled entry terminates the table.
1913  *
1914  * See __register_sysctl_paths for more details.
1915  */
1916 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1917                                                 struct ctl_table *table)
1918 {
1919         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1920                                         path, table);
1921 }
1922
1923 /**
1924  * register_sysctl_table - register a sysctl table hierarchy
1925  * @table: the top-level table structure
1926  *
1927  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1928  * array. A completely 0 filled entry terminates the table.
1929  *
1930  * See register_sysctl_paths for more details.
1931  */
1932 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1933 {
1934         static const struct ctl_path null_path[] = { {} };
1935
1936         return register_sysctl_paths(null_path, table);
1937 }
1938
1939 /**
1940  * unregister_sysctl_table - unregister a sysctl table hierarchy
1941  * @header: the header returned from register_sysctl_table
1942  *
1943  * Unregisters the sysctl table and all children. proc entries may not
1944  * actually be removed until they are no longer used by anyone.
1945  */
1946 void unregister_sysctl_table(struct ctl_table_header * header)
1947 {
1948         might_sleep();
1949
1950         if (header == NULL)
1951                 return;
1952
1953         spin_lock(&sysctl_lock);
1954         start_unregistering(header);
1955         if (!--header->parent->count) {
1956                 WARN_ON(1);
1957                 kfree(header->parent);
1958         }
1959         if (!--header->count)
1960                 kfree(header);
1961         spin_unlock(&sysctl_lock);
1962 }
1963
1964 int sysctl_is_seen(struct ctl_table_header *p)
1965 {
1966         struct ctl_table_set *set = p->set;
1967         int res;
1968         spin_lock(&sysctl_lock);
1969         if (p->unregistering)
1970                 res = 0;
1971         else if (!set->is_seen)
1972                 res = 1;
1973         else
1974                 res = set->is_seen(set);
1975         spin_unlock(&sysctl_lock);
1976         return res;
1977 }
1978
1979 void setup_sysctl_set(struct ctl_table_set *p,
1980         struct ctl_table_set *parent,
1981         int (*is_seen)(struct ctl_table_set *))
1982 {
1983         INIT_LIST_HEAD(&p->list);
1984         p->parent = parent ? parent : &sysctl_table_root.default_set;
1985         p->is_seen = is_seen;
1986 }
1987
1988 #else /* !CONFIG_SYSCTL */
1989 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1990 {
1991         return NULL;
1992 }
1993
1994 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1995                                                     struct ctl_table *table)
1996 {
1997         return NULL;
1998 }
1999
2000 void unregister_sysctl_table(struct ctl_table_header * table)
2001 {
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 }
2009
2010 void sysctl_head_put(struct ctl_table_header *head)
2011 {
2012 }
2013
2014 #endif /* CONFIG_SYSCTL */
2015
2016 /*
2017  * /proc/sys support
2018  */
2019
2020 #ifdef CONFIG_PROC_SYSCTL
2021
2022 static int _proc_do_string(void* data, int maxlen, int write,
2023                            void __user *buffer,
2024                            size_t *lenp, loff_t *ppos)
2025 {
2026         size_t len;
2027         char __user *p;
2028         char c;
2029
2030         if (!data || !maxlen || !*lenp) {
2031                 *lenp = 0;
2032                 return 0;
2033         }
2034
2035         if (write) {
2036                 len = 0;
2037                 p = buffer;
2038                 while (len < *lenp) {
2039                         if (get_user(c, p++))
2040                                 return -EFAULT;
2041                         if (c == 0 || c == '\n')
2042                                 break;
2043                         len++;
2044                 }
2045                 if (len >= maxlen)
2046                         len = maxlen-1;
2047                 if(copy_from_user(data, buffer, len))
2048                         return -EFAULT;
2049                 ((char *) data)[len] = 0;
2050                 *ppos += *lenp;
2051         } else {
2052                 len = strlen(data);
2053                 if (len > maxlen)
2054                         len = maxlen;
2055
2056                 if (*ppos > len) {
2057                         *lenp = 0;
2058                         return 0;
2059                 }
2060
2061                 data += *ppos;
2062                 len  -= *ppos;
2063
2064                 if (len > *lenp)
2065                         len = *lenp;
2066                 if (len)
2067                         if(copy_to_user(buffer, data, len))
2068                                 return -EFAULT;
2069                 if (len < *lenp) {
2070                         if(put_user('\n', ((char __user *) buffer) + len))
2071                                 return -EFAULT;
2072                         len++;
2073                 }
2074                 *lenp = len;
2075                 *ppos += len;
2076         }
2077         return 0;
2078 }
2079
2080 /**
2081  * proc_dostring - read a string sysctl
2082  * @table: the sysctl table
2083  * @write: %TRUE if this is a write to the sysctl file
2084  * @buffer: the user buffer
2085  * @lenp: the size of the user buffer
2086  * @ppos: file position
2087  *
2088  * Reads/writes a string from/to the user buffer. If the kernel
2089  * buffer provided is not large enough to hold the string, the
2090  * string is truncated. The copied string is %NULL-terminated.
2091  * If the string is being read by the user process, it is copied
2092  * and a newline '\n' is added. It is truncated if the buffer is
2093  * not large enough.
2094  *
2095  * Returns 0 on success.
2096  */
2097 int proc_dostring(struct ctl_table *table, int write,
2098                   void __user *buffer, size_t *lenp, loff_t *ppos)
2099 {
2100         return _proc_do_string(table->data, table->maxlen, write,
2101                                buffer, lenp, ppos);
2102 }
2103
2104 static size_t proc_skip_spaces(char **buf)
2105 {
2106         size_t ret;
2107         char *tmp = skip_spaces(*buf);
2108         ret = tmp - *buf;
2109         *buf = tmp;
2110         return ret;
2111 }
2112
2113 static void proc_skip_char(char **buf, size_t *size, const char v)
2114 {
2115         while (*size) {
2116                 if (**buf != v)
2117                         break;
2118                 (*size)--;
2119                 (*buf)++;
2120         }
2121 }
2122
2123 #define TMPBUFLEN 22
2124 /**
2125  * proc_get_long - reads an ASCII formatted integer from a user buffer
2126  *
2127  * @buf: a kernel buffer
2128  * @size: size of the kernel buffer
2129  * @val: this is where the number will be stored
2130  * @neg: set to %TRUE if number is negative
2131  * @perm_tr: a vector which contains the allowed trailers
2132  * @perm_tr_len: size of the perm_tr vector
2133  * @tr: pointer to store the trailer character
2134  *
2135  * In case of success %0 is returned and @buf and @size are updated with
2136  * the amount of bytes read. If @tr is non-NULL and a trailing
2137  * character exists (size is non-zero after returning from this
2138  * function), @tr is updated with the trailing character.
2139  */
2140 static int proc_get_long(char **buf, size_t *size,
2141                           unsigned long *val, bool *neg,
2142                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2143 {
2144         int len;
2145         char *p, tmp[TMPBUFLEN];
2146
2147         if (!*size)
2148                 return -EINVAL;
2149
2150         len = *size;
2151         if (len > TMPBUFLEN - 1)
2152                 len = TMPBUFLEN - 1;
2153
2154         memcpy(tmp, *buf, len);
2155
2156         tmp[len] = 0;
2157         p = tmp;
2158         if (*p == '-' && *size > 1) {
2159                 *neg = true;
2160                 p++;
2161         } else
2162                 *neg = false;
2163         if (!isdigit(*p))
2164                 return -EINVAL;
2165
2166         *val = simple_strtoul(p, &p, 0);
2167
2168         len = p - tmp;
2169
2170         /* We don't know if the next char is whitespace thus we may accept
2171          * invalid integers (e.g. 1234...a) or two integers instead of one
2172          * (e.g. 123...1). So lets not allow such large numbers. */
2173         if (len == TMPBUFLEN - 1)
2174                 return -EINVAL;
2175
2176         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2177                 return -EINVAL;
2178
2179         if (tr && (len < *size))
2180                 *tr = *p;
2181
2182         *buf += len;
2183         *size -= len;
2184
2185         return 0;
2186 }
2187
2188 /**
2189  * proc_put_long - converts an integer to a decimal ASCII formatted string
2190  *
2191  * @buf: the user buffer
2192  * @size: the size of the user buffer
2193  * @val: the integer to be converted
2194  * @neg: sign of the number, %TRUE for negative
2195  *
2196  * In case of success %0 is returned and @buf and @size are updated with
2197  * the amount of bytes written.
2198  */
2199 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2200                           bool neg)
2201 {
2202         int len;
2203         char tmp[TMPBUFLEN], *p = tmp;
2204
2205         sprintf(p, "%s%lu", neg ? "-" : "", val);
2206         len = strlen(tmp);
2207         if (len > *size)
2208                 len = *size;
2209         if (copy_to_user(*buf, tmp, len))
2210                 return -EFAULT;
2211         *size -= len;
2212         *buf += len;
2213         return 0;
2214 }
2215 #undef TMPBUFLEN
2216
2217 static int proc_put_char(void __user **buf, size_t *size, char c)
2218 {
2219         if (*size) {
2220                 char __user **buffer = (char __user **)buf;
2221                 if (put_user(c, *buffer))
2222                         return -EFAULT;
2223                 (*size)--, (*buffer)++;
2224                 *buf = *buffer;
2225         }
2226         return 0;
2227 }
2228
2229 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2230                                  int *valp,
2231                                  int write, void *data)
2232 {
2233         if (write) {
2234                 *valp = *negp ? -*lvalp : *lvalp;
2235         } else {
2236                 int val = *valp;
2237                 if (val < 0) {
2238                         *negp = true;
2239                         *lvalp = (unsigned long)-val;
2240                 } else {
2241                         *negp = false;
2242                         *lvalp = (unsigned long)val;
2243                 }
2244         }
2245         return 0;
2246 }
2247
2248 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2249
2250 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2251                   int write, void __user *buffer,
2252                   size_t *lenp, loff_t *ppos,
2253                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2254                               int write, void *data),
2255                   void *data)
2256 {
2257         int *i, vleft, first = 1, err = 0;
2258         unsigned long page = 0;
2259         size_t left;
2260         char *kbuf;
2261
2262         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2263                 *lenp = 0;
2264                 return 0;
2265         }
2266
2267         i = (int *) tbl_data;
2268         vleft = table->maxlen / sizeof(*i);
2269         left = *lenp;
2270
2271         if (!conv)
2272                 conv = do_proc_dointvec_conv;
2273
2274         if (write) {
2275                 if (left > PAGE_SIZE - 1)
2276                         left = PAGE_SIZE - 1;
2277                 page = __get_free_page(GFP_TEMPORARY);
2278                 kbuf = (char *) page;
2279                 if (!kbuf)
2280                         return -ENOMEM;
2281                 if (copy_from_user(kbuf, buffer, left)) {
2282                         err = -EFAULT;
2283                         goto free;
2284                 }
2285                 kbuf[left] = 0;
2286         }
2287
2288         for (; left && vleft--; i++, first=0) {
2289                 unsigned long lval;
2290                 bool neg;
2291
2292                 if (write) {
2293                         left -= proc_skip_spaces(&kbuf);
2294
2295                         if (!left)
2296                                 break;
2297                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2298                                              proc_wspace_sep,
2299                                              sizeof(proc_wspace_sep), NULL);
2300                         if (err)
2301                                 break;
2302                         if (conv(&neg, &lval, i, 1, data)) {
2303                                 err = -EINVAL;
2304                                 break;
2305                         }
2306                 } else {
2307                         if (conv(&neg, &lval, i, 0, data)) {
2308                                 err = -EINVAL;
2309                                 break;
2310                         }
2311                         if (!first)
2312                                 err = proc_put_char(&buffer, &left, '\t');
2313                         if (err)
2314                                 break;
2315                         err = proc_put_long(&buffer, &left, lval, neg);
2316                         if (err)
2317                                 break;
2318                 }
2319         }
2320
2321         if (!write && !first && left && !err)
2322                 err = proc_put_char(&buffer, &left, '\n');
2323         if (write && !err && left)
2324                 left -= proc_skip_spaces(&kbuf);
2325 free:
2326         if (write) {
2327                 free_page(page);
2328                 if (first)
2329                         return err ? : -EINVAL;
2330         }
2331         *lenp -= left;
2332         *ppos += *lenp;
2333         return err;
2334 }
2335
2336 static int do_proc_dointvec(struct ctl_table *table, int write,
2337                   void __user *buffer, size_t *lenp, loff_t *ppos,
2338                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2339                               int write, void *data),
2340                   void *data)
2341 {
2342         return __do_proc_dointvec(table->data, table, write,
2343                         buffer, lenp, ppos, conv, data);
2344 }
2345
2346 /**
2347  * proc_dointvec - read a vector of integers
2348  * @table: the sysctl table
2349  * @write: %TRUE if this is a write to the sysctl file
2350  * @buffer: the user buffer
2351  * @lenp: the size of the user buffer
2352  * @ppos: file position
2353  *
2354  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2355  * values from/to the user buffer, treated as an ASCII string.
2356  *
2357  * Returns 0 on success.
2358  */
2359 int proc_dointvec(struct ctl_table *table, int write,
2360                      void __user *buffer, size_t *lenp, loff_t *ppos)
2361 {
2362     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2363                             NULL,NULL);
2364 }
2365
2366 /*
2367  * Taint values can only be increased
2368  * This means we can safely use a temporary.
2369  */
2370 static int proc_taint(struct ctl_table *table, int write,
2371                                void __user *buffer, size_t *lenp, loff_t *ppos)
2372 {
2373         struct ctl_table t;
2374         unsigned long tmptaint = get_taint();
2375         int err;
2376
2377         if (write && !capable(CAP_SYS_ADMIN))
2378                 return -EPERM;
2379
2380         t = *table;
2381         t.data = &tmptaint;
2382         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2383         if (err < 0)
2384                 return err;
2385
2386         if (write) {
2387                 /*
2388                  * Poor man's atomic or. Not worth adding a primitive
2389                  * to everyone's atomic.h for this
2390                  */
2391                 int i;
2392                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2393                         if ((tmptaint >> i) & 1)
2394                                 add_taint(i);
2395                 }
2396         }
2397
2398         return err;
2399 }
2400
2401 struct do_proc_dointvec_minmax_conv_param {
2402         int *min;
2403         int *max;
2404 };
2405
2406 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2407                                         int *valp,
2408                                         int write, void *data)
2409 {
2410         struct do_proc_dointvec_minmax_conv_param *param = data;
2411         if (write) {
2412                 int val = *negp ? -*lvalp : *lvalp;
2413                 if ((param->min && *param->min > val) ||
2414                     (param->max && *param->max < val))
2415                         return -EINVAL;
2416                 *valp = val;
2417         } else {
2418                 int val = *valp;
2419                 if (val < 0) {
2420                         *negp = true;
2421                         *lvalp = (unsigned long)-val;
2422                 } else {
2423                         *negp = false;
2424                         *lvalp = (unsigned long)val;
2425                 }
2426         }
2427         return 0;
2428 }
2429
2430 /**
2431  * proc_dointvec_minmax - read a vector of integers with min/max values
2432  * @table: the sysctl table
2433  * @write: %TRUE if this is a write to the sysctl file
2434  * @buffer: the user buffer
2435  * @lenp: the size of the user buffer
2436  * @ppos: file position
2437  *
2438  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2439  * values from/to the user buffer, treated as an ASCII string.
2440  *
2441  * This routine will ensure the values are within the range specified by
2442  * table->extra1 (min) and table->extra2 (max).
2443  *
2444  * Returns 0 on success.
2445  */
2446 int proc_dointvec_minmax(struct ctl_table *table, int write,
2447                   void __user *buffer, size_t *lenp, loff_t *ppos)
2448 {
2449         struct do_proc_dointvec_minmax_conv_param param = {
2450                 .min = (int *) table->extra1,
2451                 .max = (int *) table->extra2,
2452         };
2453         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2454                                 do_proc_dointvec_minmax_conv, &param);
2455 }
2456
2457 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2458                                      void __user *buffer,
2459                                      size_t *lenp, loff_t *ppos,
2460                                      unsigned long convmul,
2461                                      unsigned long convdiv)
2462 {
2463         unsigned long *i, *min, *max;
2464         int vleft, first = 1, err = 0;
2465         unsigned long page = 0;
2466         size_t left;
2467         char *kbuf;
2468
2469         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2470                 *lenp = 0;
2471                 return 0;
2472         }
2473
2474         i = (unsigned long *) data;
2475         min = (unsigned long *) table->extra1;
2476         max = (unsigned long *) table->extra2;
2477         vleft = table->maxlen / sizeof(unsigned long);
2478         left = *lenp;
2479
2480         if (write) {
2481                 if (left > PAGE_SIZE - 1)
2482                         left = PAGE_SIZE - 1;
2483                 page = __get_free_page(GFP_TEMPORARY);
2484                 kbuf = (char *) page;
2485                 if (!kbuf)
2486                         return -ENOMEM;
2487                 if (copy_from_user(kbuf, buffer, left)) {
2488                         err = -EFAULT;
2489                         goto free;
2490                 }
2491                 kbuf[left] = 0;
2492         }
2493
2494         for (; left && vleft--; i++, first = 0) {
2495                 unsigned long val;
2496
2497                 if (write) {
2498                         bool neg;
2499
2500                         left -= proc_skip_spaces(&kbuf);
2501
2502                         err = proc_get_long(&kbuf, &left, &val, &neg,
2503                                              proc_wspace_sep,
2504                                              sizeof(proc_wspace_sep), NULL);
2505                         if (err)
2506                                 break;
2507                         if (neg)
2508                                 continue;
2509                         if ((min && val < *min) || (max && val > *max))
2510                                 continue;
2511                         *i = val;
2512                 } else {
2513                         val = convdiv * (*i) / convmul;
2514                         if (!first)
2515                                 err = proc_put_char(&buffer, &left, '\t');
2516                         err = proc_put_long(&buffer, &left, val, false);
2517                         if (err)
2518                                 break;
2519                 }
2520         }
2521
2522         if (!write && !first && left && !err)
2523                 err = proc_put_char(&buffer, &left, '\n');
2524         if (write && !err)
2525                 left -= proc_skip_spaces(&kbuf);
2526 free:
2527         if (write) {
2528                 free_page(page);
2529                 if (first)
2530                         return err ? : -EINVAL;
2531         }
2532         *lenp -= left;
2533         *ppos += *lenp;
2534         return err;
2535 }
2536
2537 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2538                                      void __user *buffer,
2539                                      size_t *lenp, loff_t *ppos,
2540                                      unsigned long convmul,
2541                                      unsigned long convdiv)
2542 {
2543         return __do_proc_doulongvec_minmax(table->data, table, write,
2544                         buffer, lenp, ppos, convmul, convdiv);
2545 }
2546
2547 /**
2548  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2549  * @table: the sysctl table
2550  * @write: %TRUE if this is a write to the sysctl file
2551  * @buffer: the user buffer
2552  * @lenp: the size of the user buffer
2553  * @ppos: file position
2554  *
2555  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2556  * values from/to the user buffer, treated as an ASCII string.
2557  *
2558  * This routine will ensure the values are within the range specified by
2559  * table->extra1 (min) and table->extra2 (max).
2560  *
2561  * Returns 0 on success.
2562  */
2563 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2564                            void __user *buffer, size_t *lenp, loff_t *ppos)
2565 {
2566     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2567 }
2568
2569 /**
2570  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2571  * @table: the sysctl table
2572  * @write: %TRUE if this is a write to the sysctl file
2573  * @buffer: the user buffer
2574  * @lenp: the size of the user buffer
2575  * @ppos: file position
2576  *
2577  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2578  * values from/to the user buffer, treated as an ASCII string. The values
2579  * are treated as milliseconds, and converted to jiffies when they are stored.
2580  *
2581  * This routine will ensure the values are within the range specified by
2582  * table->extra1 (min) and table->extra2 (max).
2583  *
2584  * Returns 0 on success.
2585  */
2586 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2587                                       void __user *buffer,
2588                                       size_t *lenp, loff_t *ppos)
2589 {
2590     return do_proc_doulongvec_minmax(table, write, buffer,
2591                                      lenp, ppos, HZ, 1000l);
2592 }
2593
2594
2595 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2596                                          int *valp,
2597                                          int write, void *data)
2598 {
2599         if (write) {
2600                 if (*lvalp > LONG_MAX / HZ)
2601                         return 1;
2602                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2603         } else {
2604                 int val = *valp;
2605                 unsigned long lval;
2606                 if (val < 0) {
2607                         *negp = true;
2608                         lval = (unsigned long)-val;
2609                 } else {
2610                         *negp = false;
2611                         lval = (unsigned long)val;
2612                 }
2613                 *lvalp = lval / HZ;
2614         }
2615         return 0;
2616 }
2617
2618 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2619                                                 int *valp,
2620                                                 int write, void *data)
2621 {
2622         if (write) {
2623                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2624                         return 1;
2625                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2626         } else {
2627                 int val = *valp;
2628                 unsigned long lval;
2629                 if (val < 0) {
2630                         *negp = true;
2631                         lval = (unsigned long)-val;
2632                 } else {
2633                         *negp = false;
2634                         lval = (unsigned long)val;
2635                 }
2636                 *lvalp = jiffies_to_clock_t(lval);
2637         }
2638         return 0;
2639 }
2640
2641 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2642                                             int *valp,
2643                                             int write, void *data)
2644 {
2645         if (write) {
2646                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2647         } else {
2648                 int val = *valp;
2649                 unsigned long lval;
2650                 if (val < 0) {
2651                         *negp = true;
2652                         lval = (unsigned long)-val;
2653                 } else {
2654                         *negp = false;
2655                         lval = (unsigned long)val;
2656                 }
2657                 *lvalp = jiffies_to_msecs(lval);
2658         }
2659         return 0;
2660 }
2661
2662 /**
2663  * proc_dointvec_jiffies - read a vector of integers as seconds
2664  * @table: the sysctl table
2665  * @write: %TRUE if this is a write to the sysctl file
2666  * @buffer: the user buffer
2667  * @lenp: the size of the user buffer
2668  * @ppos: file position
2669  *
2670  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2671  * values from/to the user buffer, treated as an ASCII string.
2672  * The values read are assumed to be in seconds, and are converted into
2673  * jiffies.
2674  *
2675  * Returns 0 on success.
2676  */
2677 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2678                           void __user *buffer, size_t *lenp, loff_t *ppos)
2679 {
2680     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2681                             do_proc_dointvec_jiffies_conv,NULL);
2682 }
2683
2684 /**
2685  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2686  * @table: the sysctl table
2687  * @write: %TRUE if this is a write to the sysctl file
2688  * @buffer: the user buffer
2689  * @lenp: the size of the user buffer
2690  * @ppos: pointer to the file position
2691  *
2692  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2693  * values from/to the user buffer, treated as an ASCII string.
2694  * The values read are assumed to be in 1/USER_HZ seconds, and
2695  * are converted into jiffies.
2696  *
2697  * Returns 0 on success.
2698  */
2699 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2700                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2701 {
2702     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2703                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2704 }
2705
2706 /**
2707  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2708  * @table: the sysctl table
2709  * @write: %TRUE if this is a write to the sysctl file
2710  * @buffer: the user buffer
2711  * @lenp: the size of the user buffer
2712  * @ppos: file position
2713  * @ppos: the current position in the file
2714  *
2715  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2716  * values from/to the user buffer, treated as an ASCII string.
2717  * The values read are assumed to be in 1/1000 seconds, and
2718  * are converted into jiffies.
2719  *
2720  * Returns 0 on success.
2721  */
2722 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2723                              void __user *buffer, size_t *lenp, loff_t *ppos)
2724 {
2725         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2726                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2727 }
2728
2729 static int proc_do_cad_pid(struct ctl_table *table, int write,
2730                            void __user *buffer, size_t *lenp, loff_t *ppos)
2731 {
2732         struct pid *new_pid;
2733         pid_t tmp;
2734         int r;
2735
2736         tmp = pid_vnr(cad_pid);
2737
2738         r = __do_proc_dointvec(&tmp, table, write, buffer,
2739                                lenp, ppos, NULL, NULL);
2740         if (r || !write)
2741                 return r;
2742
2743         new_pid = find_get_pid(tmp);
2744         if (!new_pid)
2745                 return -ESRCH;
2746
2747         put_pid(xchg(&cad_pid, new_pid));
2748         return 0;
2749 }
2750
2751 /**
2752  * proc_do_large_bitmap - read/write from/to a large bitmap
2753  * @table: the sysctl table
2754  * @write: %TRUE if this is a write to the sysctl file
2755  * @buffer: the user buffer
2756  * @lenp: the size of the user buffer
2757  * @ppos: file position
2758  *
2759  * The bitmap is stored at table->data and the bitmap length (in bits)
2760  * in table->maxlen.
2761  *
2762  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2763  * large bitmaps may be represented in a compact manner. Writing into
2764  * the file will clear the bitmap then update it with the given input.
2765  *
2766  * Returns 0 on success.
2767  */
2768 int proc_do_large_bitmap(struct ctl_table *table, int write,
2769                          void __user *buffer, size_t *lenp, loff_t *ppos)
2770 {
2771         int err = 0;
2772         bool first = 1;
2773         size_t left = *lenp;
2774         unsigned long bitmap_len = table->maxlen;
2775         unsigned long *bitmap = (unsigned long *) table->data;
2776         unsigned long *tmp_bitmap = NULL;
2777         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2778
2779         if (!bitmap_len || !left || (*ppos && !write)) {
2780                 *lenp = 0;
2781                 return 0;
2782         }
2783
2784         if (write) {
2785                 unsigned long page = 0;
2786                 char *kbuf;
2787
2788                 if (left > PAGE_SIZE - 1)
2789                         left = PAGE_SIZE - 1;
2790
2791                 page = __get_free_page(GFP_TEMPORARY);
2792                 kbuf = (char *) page;
2793                 if (!kbuf)
2794                         return -ENOMEM;
2795                 if (copy_from_user(kbuf, buffer, left)) {
2796                         free_page(page);
2797                         return -EFAULT;
2798                 }
2799                 kbuf[left] = 0;
2800
2801                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2802                                      GFP_KERNEL);
2803                 if (!tmp_bitmap) {
2804                         free_page(page);
2805                         return -ENOMEM;
2806                 }
2807                 proc_skip_char(&kbuf, &left, '\n');
2808                 while (!err && left) {
2809                         unsigned long val_a, val_b;
2810                         bool neg;
2811
2812                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2813                                              sizeof(tr_a), &c);
2814                         if (err)
2815                                 break;
2816                         if (val_a >= bitmap_len || neg) {
2817                                 err = -EINVAL;
2818                                 break;
2819                         }
2820
2821                         val_b = val_a;
2822                         if (left) {
2823                                 kbuf++;
2824                                 left--;
2825                         }
2826
2827                         if (c == '-') {
2828                                 err = proc_get_long(&kbuf, &left, &val_b,
2829                                                      &neg, tr_b, sizeof(tr_b),
2830                                                      &c);
2831                                 if (err)
2832                                         break;
2833                                 if (val_b >= bitmap_len || neg ||
2834                                     val_a > val_b) {
2835                                         err = -EINVAL;
2836                                         break;
2837                                 }
2838                                 if (left) {
2839                                         kbuf++;
2840                                         left--;
2841                                 }
2842                         }
2843
2844                         while (val_a <= val_b)
2845                                 set_bit(val_a++, tmp_bitmap);
2846
2847                         first = 0;
2848                         proc_skip_char(&kbuf, &left, '\n');
2849                 }
2850                 free_page(page);
2851         } else {
2852                 unsigned long bit_a, bit_b = 0;
2853
2854                 while (left) {
2855                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2856                         if (bit_a >= bitmap_len)
2857                                 break;
2858                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2859                                                    bit_a + 1) - 1;
2860
2861                         if (!first) {
2862                                 err = proc_put_char(&buffer, &left, ',');
2863                                 if (err)
2864                                         break;
2865                         }
2866                         err = proc_put_long(&buffer, &left, bit_a, false);
2867                         if (err)
2868                                 break;
2869                         if (bit_a != bit_b) {
2870                                 err = proc_put_char(&buffer, &left, '-');
2871                                 if (err)
2872                                         break;
2873                                 err = proc_put_long(&buffer, &left, bit_b, false);
2874                                 if (err)
2875                                         break;
2876                         }
2877
2878                         first = 0; bit_b++;
2879                 }
2880                 if (!err)
2881                         err = proc_put_char(&buffer, &left, '\n');
2882         }
2883
2884         if (!err) {
2885                 if (write) {
2886                         if (*ppos)
2887                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2888                         else
2889                                 memcpy(bitmap, tmp_bitmap,
2890                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2891                 }
2892                 kfree(tmp_bitmap);
2893                 *lenp -= left;
2894                 *ppos += *lenp;
2895                 return 0;
2896         } else {
2897                 kfree(tmp_bitmap);
2898                 return err;
2899         }
2900 }
2901
2902 #else /* CONFIG_PROC_FS */
2903
2904 int proc_dostring(struct ctl_table *table, int write,
2905                   void __user *buffer, size_t *lenp, loff_t *ppos)
2906 {
2907         return -ENOSYS;
2908 }
2909
2910 int proc_dointvec(struct ctl_table *table, int write,
2911                   void __user *buffer, size_t *lenp, loff_t *ppos)
2912 {
2913         return -ENOSYS;
2914 }
2915
2916 int proc_dointvec_minmax(struct ctl_table *table, int write,
2917                     void __user *buffer, size_t *lenp, loff_t *ppos)
2918 {
2919         return -ENOSYS;
2920 }
2921
2922 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2923                     void __user *buffer, size_t *lenp, loff_t *ppos)
2924 {
2925         return -ENOSYS;
2926 }
2927
2928 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2929                     void __user *buffer, size_t *lenp, loff_t *ppos)
2930 {
2931         return -ENOSYS;
2932 }
2933
2934 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2935                              void __user *buffer, size_t *lenp, loff_t *ppos)
2936 {
2937         return -ENOSYS;
2938 }
2939
2940 int proc_doulongvec_minmax(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_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2947                                       void __user *buffer,
2948                                       size_t *lenp, loff_t *ppos)
2949 {
2950     return -ENOSYS;
2951 }
2952
2953
2954 #endif /* CONFIG_PROC_FS */
2955
2956 /*
2957  * No sense putting this after each symbol definition, twice,
2958  * exception granted :-)
2959  */
2960 EXPORT_SYMBOL(proc_dointvec);
2961 EXPORT_SYMBOL(proc_dointvec_jiffies);
2962 EXPORT_SYMBOL(proc_dointvec_minmax);
2963 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2964 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2965 EXPORT_SYMBOL(proc_dostring);
2966 EXPORT_SYMBOL(proc_doulongvec_minmax);
2967 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2968 EXPORT_SYMBOL(register_sysctl_table);
2969 EXPORT_SYMBOL(register_sysctl_paths);
2970 EXPORT_SYMBOL(unregister_sysctl_table);