kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/signal.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/security.h>
  29 #include <linux/ctype.h>
  30 #include <linux/kmemcheck.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/ratelimit.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_event.h>
  54 #include <linux/kprobes.h>
  55
  56 #include <asm/uaccess.h>
  57 #include <asm/processor.h>
  58
  59 #ifdef CONFIG_X86
  60 #include <asm/nmi.h>
  61 #include <asm/stacktrace.h>
  62 #include <asm/io.h>
  63 #endif
  64 #ifdef CONFIG_BSD_PROCESS_ACCT
  65 #include <linux/acct.h>
  66 #endif
  67 #ifdef CONFIG_RT_MUTEXES
  68 #include <linux/rtmutex.h>
  69 #endif
  70 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  71 #include <linux/lockdep.h>
  72 #endif
  73 #ifdef CONFIG_CHR_DEV_SG
  74 #include <scsi/sg.h>
  75 #endif
  76
  77
  78 #if defined(CONFIG_SYSCTL)
  79
  80 /* External variables not in a header file. */
  81 extern int sysctl_overcommit_memory;
  82 extern int sysctl_overcommit_ratio;
  83 extern int sysctl_panic_on_oom;
  84 extern int sysctl_oom_kill_allocating_task;
  85 extern int sysctl_oom_dump_tasks;
  86 extern int max_threads;
  87 extern int core_uses_pid;
  88 extern int suid_dumpable;
  89 extern char core_pattern[];
  90 extern unsigned int core_pipe_limit;
  91 extern int pid_max;
  92 extern int min_free_kbytes;
  93 extern int pid_max_min, pid_max_max;
  94 extern int sysctl_drop_caches;
  95 extern int percpu_pagelist_fraction;
  96 extern int compat_log;
  97 extern int latencytop_enabled;
  98 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  99 #ifndef CONFIG_MMU
 100 extern int sysctl_nr_trim_pages;
 101 #endif
 102 #ifdef CONFIG_BLOCK
 103 extern int blk_iopoll_enabled;
 104 #endif
 105
 106 /* Constants used for minimum and  maximum */
 107 #ifdef CONFIG_DETECT_SOFTLOCKUP
 108 static int sixty = 60;
 109 static int neg_one = -1;
 110 #endif
 111
 112 static int zero;
 113 static int __maybe_unused one = 1;
 114 static int __maybe_unused two = 2;
 115 static unsigned long one_ul = 1;
 116 static int one_hundred = 100;
 117 #ifdef CONFIG_PRINTK
 118 static int ten_thousand = 10000;
 119 #endif
 120
 121 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 122 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 123
 124 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 125 static int maxolduid = 65535;
 126 static int minolduid;
 127 static int min_percpu_pagelist_fract = 8;
 128
 129 static int ngroups_max = NGROUPS_MAX;
 130
 131 #ifdef CONFIG_SPARC
 132 #include <asm/system.h>
 133 #endif
 134
 135 #ifdef CONFIG_SPARC64
 136 extern int sysctl_tsb_ratio;
 137 #endif
 138
 139 #ifdef __hppa__
 140 extern int pwrsw_enabled;
 141 extern int unaligned_enabled;
 142 #endif
 143
 144 #ifdef CONFIG_S390
 145 #ifdef CONFIG_MATHEMU
 146 extern int sysctl_ieee_emulation_warnings;
 147 #endif
 148 extern int sysctl_userprocess_debug;
 149 extern int spin_retry;
 150 #endif
 151
 152 #ifdef CONFIG_IA64
 153 extern int no_unaligned_warning;
 154 extern int unaligned_dump_stack;
 155 #endif
 156
 157 extern struct ratelimit_state printk_ratelimit_state;
 158
 159 #ifdef CONFIG_PROC_SYSCTL
 160 static int proc_do_cad_pid(struct ctl_table *table, int write,
 161                   void __user *buffer, size_t *lenp, loff_t *ppos);
 162 static int proc_taint(struct ctl_table *table, int write,
 163                                void __user *buffer, size_t *lenp, loff_t *ppos);
 164 #endif
 165
 166 static struct ctl_table root_table[];
 167 static struct ctl_table_root sysctl_table_root;
 168 static struct ctl_table_header root_table_header = {
 169         .count = 1,
 170         .ctl_table = root_table,
 171         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 172         .root = &sysctl_table_root,
 173         .set = &sysctl_table_root.default_set,
 174 };
 175 static struct ctl_table_root sysctl_table_root = {
 176         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 177         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 178 };
 179
 180 static struct ctl_table kern_table[];
 181 static struct ctl_table vm_table[];
 182 static struct ctl_table fs_table[];
 183 static struct ctl_table debug_table[];
 184 static struct ctl_table dev_table[];
 185 extern struct ctl_table random_table[];
 186 #ifdef CONFIG_INOTIFY_USER
 187 extern struct ctl_table inotify_table[];
 188 #endif
 189 #ifdef CONFIG_EPOLL
 190 extern struct ctl_table epoll_table[];
 191 #endif
 192
 193 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 194 int sysctl_legacy_va_layout;
 195 #endif
 196
 197 /* The default sysctl tables: */
 198
 199 static struct ctl_table root_table[] = {
 200         {
 201                 .procname       = "kernel",
 202                 .mode           = 0555,
 203                 .child          = kern_table,
 204         },
 205         {
 206                 .procname       = "vm",
 207                 .mode           = 0555,
 208                 .child          = vm_table,
 209         },
 210         {
 211                 .procname       = "fs",
 212                 .mode           = 0555,
 213                 .child          = fs_table,
 214         },
 215         {
 216                 .procname       = "debug",
 217                 .mode           = 0555,
 218                 .child          = debug_table,
 219         },
 220         {
 221                 .procname       = "dev",
 222                 .mode           = 0555,
 223                 .child          = dev_table,
 224         },
 225 /*
 226  * NOTE: do not add new entries to this table unless you have read
 227  * Documentation/sysctl/ctl_unnumbered.txt
 228  */
 229         { }
 230 };
 231
 232 #ifdef CONFIG_SCHED_DEBUG
 233 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 234 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 235 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 236 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 237 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 238 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 239 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
 240 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
 241 #endif
 242
 243 static struct ctl_table kern_table[] = {
 244         {
 245                 .procname       = "sched_child_runs_first",
 246                 .data           = &sysctl_sched_child_runs_first,
 247                 .maxlen         = sizeof(unsigned int),
 248                 .mode           = 0644,
 249                 .proc_handler   = proc_dointvec,
 250         },
 251 #ifdef CONFIG_SCHED_DEBUG
 252         {
 253                 .procname       = "sched_min_granularity_ns",
 254                 .data           = &sysctl_sched_min_granularity,
 255                 .maxlen         = sizeof(unsigned int),
 256                 .mode           = 0644,
 257                 .proc_handler   = sched_proc_update_handler,
 258                 .extra1         = &min_sched_granularity_ns,
 259                 .extra2         = &max_sched_granularity_ns,
 260         },
 261         {
 262                 .procname       = "sched_latency_ns",
 263                 .data           = &sysctl_sched_latency,
 264                 .maxlen         = sizeof(unsigned int),
 265                 .mode           = 0644,
 266                 .proc_handler   = sched_proc_update_handler,
 267                 .extra1         = &min_sched_granularity_ns,
 268                 .extra2         = &max_sched_granularity_ns,
 269         },
 270         {
 271                 .procname       = "sched_wakeup_granularity_ns",
 272                 .data           = &sysctl_sched_wakeup_granularity,
 273                 .maxlen         = sizeof(unsigned int),
 274                 .mode           = 0644,
 275                 .proc_handler   = sched_proc_update_handler,
 276                 .extra1         = &min_wakeup_granularity_ns,
 277                 .extra2         = &max_wakeup_granularity_ns,
 278         },
 279         {
 280                 .procname       = "sched_shares_ratelimit",
 281                 .data           = &sysctl_sched_shares_ratelimit,
 282                 .maxlen         = sizeof(unsigned int),
 283                 .mode           = 0644,
 284                 .proc_handler   = sched_proc_update_handler,
 285                 .extra1         = &min_sched_shares_ratelimit,
 286                 .extra2         = &max_sched_shares_ratelimit,
 287         },
 288         {
 289                 .procname       = "sched_tunable_scaling",
 290                 .data           = &sysctl_sched_tunable_scaling,
 291                 .maxlen         = sizeof(enum sched_tunable_scaling),
 292                 .mode           = 0644,
 293                 .proc_handler   = sched_proc_update_handler,
 294                 .extra1         = &min_sched_tunable_scaling,
 295                 .extra2         = &max_sched_tunable_scaling,
 296         },
 297         {
 298                 .procname       = "sched_shares_thresh",
 299                 .data           = &sysctl_sched_shares_thresh,
 300                 .maxlen         = sizeof(unsigned int),
 301                 .mode           = 0644,
 302                 .proc_handler   = proc_dointvec_minmax,
 303                 .extra1         = &zero,
 304         },
 305         {
 306                 .procname       = "sched_migration_cost",
 307                 .data           = &sysctl_sched_migration_cost,
 308                 .maxlen         = sizeof(unsigned int),
 309                 .mode           = 0644,
 310                 .proc_handler   = proc_dointvec,
 311         },
 312         {
 313                 .procname       = "sched_nr_migrate",
 314                 .data           = &sysctl_sched_nr_migrate,
 315                 .maxlen         = sizeof(unsigned int),
 316                 .mode           = 0644,
 317                 .proc_handler   = proc_dointvec,
 318         },
 319         {
 320                 .procname       = "sched_time_avg",
 321                 .data           = &sysctl_sched_time_avg,
 322                 .maxlen         = sizeof(unsigned int),
 323                 .mode           = 0644,
 324                 .proc_handler   = proc_dointvec,
 325         },
 326         {
 327                 .procname       = "timer_migration",
 328                 .data           = &sysctl_timer_migration,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = proc_dointvec_minmax,
 332                 .extra1         = &zero,
 333                 .extra2         = &one,
 334         },
 335 #endif
 336         {
 337                 .procname       = "sched_rt_period_us",
 338                 .data           = &sysctl_sched_rt_period,
 339                 .maxlen         = sizeof(unsigned int),
 340                 .mode           = 0644,
 341                 .proc_handler   = sched_rt_handler,
 342         },
 343         {
 344                 .procname       = "sched_rt_runtime_us",
 345                 .data           = &sysctl_sched_rt_runtime,
 346                 .maxlen         = sizeof(int),
 347                 .mode           = 0644,
 348                 .proc_handler   = sched_rt_handler,
 349         },
 350         {
 351                 .procname       = "sched_compat_yield",
 352                 .data           = &sysctl_sched_compat_yield,
 353                 .maxlen         = sizeof(unsigned int),
 354                 .mode           = 0644,
 355                 .proc_handler   = proc_dointvec,
 356         },
 357 #ifdef CONFIG_PROVE_LOCKING
 358         {
 359                 .procname       = "prove_locking",
 360                 .data           = &prove_locking,
 361                 .maxlen         = sizeof(int),
 362                 .mode           = 0644,
 363                 .proc_handler   = proc_dointvec,
 364         },
 365 #endif
 366 #ifdef CONFIG_LOCK_STAT
 367         {
 368                 .procname       = "lock_stat",
 369                 .data           = &lock_stat,
 370                 .maxlen         = sizeof(int),
 371                 .mode           = 0644,
 372                 .proc_handler   = proc_dointvec,
 373         },
 374 #endif
 375         {
 376                 .procname       = "panic",
 377                 .data           = &panic_timeout,
 378                 .maxlen         = sizeof(int),
 379                 .mode           = 0644,
 380                 .proc_handler   = proc_dointvec,
 381         },
 382         {
 383                 .procname       = "core_uses_pid",
 384                 .data           = &core_uses_pid,
 385                 .maxlen         = sizeof(int),
 386                 .mode           = 0644,
 387                 .proc_handler   = proc_dointvec,
 388         },
 389         {
 390                 .procname       = "core_pattern",
 391                 .data           = core_pattern,
 392                 .maxlen         = CORENAME_MAX_SIZE,
 393                 .mode           = 0644,
 394                 .proc_handler   = proc_dostring,
 395         },
 396         {
 397                 .procname       = "core_pipe_limit",
 398                 .data           = &core_pipe_limit,
 399                 .maxlen         = sizeof(unsigned int),
 400                 .mode           = 0644,
 401                 .proc_handler   = proc_dointvec,
 402         },
 403 #ifdef CONFIG_PROC_SYSCTL
 404         {
 405                 .procname       = "tainted",
 406                 .maxlen         = sizeof(long),
 407                 .mode           = 0644,
 408                 .proc_handler   = proc_taint,
 409         },
 410 #endif
 411 #ifdef CONFIG_LATENCYTOP
 412         {
 413                 .procname       = "latencytop",
 414                 .data           = &latencytop_enabled,
 415                 .maxlen         = sizeof(int),
 416                 .mode           = 0644,
 417                 .proc_handler   = proc_dointvec,
 418         },
 419 #endif
 420 #ifdef CONFIG_BLK_DEV_INITRD
 421         {
 422                 .procname       = "real-root-dev",
 423                 .data           = &real_root_dev,
 424                 .maxlen         = sizeof(int),
 425                 .mode           = 0644,
 426                 .proc_handler   = proc_dointvec,
 427         },
 428 #endif
 429         {
 430                 .procname       = "print-fatal-signals",
 431                 .data           = &print_fatal_signals,
 432                 .maxlen         = sizeof(int),
 433                 .mode           = 0644,
 434                 .proc_handler   = proc_dointvec,
 435         },
 436 #ifdef CONFIG_SPARC
 437         {
 438                 .procname       = "reboot-cmd",
 439                 .data           = reboot_command,
 440                 .maxlen         = 256,
 441                 .mode           = 0644,
 442                 .proc_handler   = proc_dostring,
 443         },
 444         {
 445                 .procname       = "stop-a",
 446                 .data           = &stop_a_enabled,
 447                 .maxlen         = sizeof (int),
 448                 .mode           = 0644,
 449                 .proc_handler   = proc_dointvec,
 450         },
 451         {
 452                 .procname       = "scons-poweroff",
 453                 .data           = &scons_pwroff,
 454                 .maxlen         = sizeof (int),
 455                 .mode           = 0644,
 456                 .proc_handler   = proc_dointvec,
 457         },
 458 #endif
 459 #ifdef CONFIG_SPARC64
 460         {
 461                 .procname       = "tsb-ratio",
 462                 .data           = &sysctl_tsb_ratio,
 463                 .maxlen         = sizeof (int),
 464                 .mode           = 0644,
 465                 .proc_handler   = proc_dointvec,
 466         },
 467 #endif
 468 #ifdef __hppa__
 469         {
 470                 .procname       = "soft-power",
 471                 .data           = &pwrsw_enabled,
 472                 .maxlen         = sizeof (int),
 473                 .mode           = 0644,
 474                 .proc_handler   = proc_dointvec,
 475         },
 476         {
 477                 .procname       = "unaligned-trap",
 478                 .data           = &unaligned_enabled,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = proc_dointvec,
 482         },
 483 #endif
 484         {
 485                 .procname       = "ctrl-alt-del",
 486                 .data           = &C_A_D,
 487                 .maxlen         = sizeof(int),
 488                 .mode           = 0644,
 489                 .proc_handler   = proc_dointvec,
 490         },
 491 #ifdef CONFIG_FUNCTION_TRACER
 492         {
 493                 .procname       = "ftrace_enabled",
 494                 .data           = &ftrace_enabled,
 495                 .maxlen         = sizeof(int),
 496                 .mode           = 0644,
 497                 .proc_handler   = ftrace_enable_sysctl,
 498         },
 499 #endif
 500 #ifdef CONFIG_STACK_TRACER
 501         {
 502                 .procname       = "stack_tracer_enabled",
 503                 .data           = &stack_tracer_enabled,
 504                 .maxlen         = sizeof(int),
 505                 .mode           = 0644,
 506                 .proc_handler   = stack_trace_sysctl,
 507         },
 508 #endif
 509 #ifdef CONFIG_TRACING
 510         {
 511                 .procname       = "ftrace_dump_on_oops",
 512                 .data           = &ftrace_dump_on_oops,
 513                 .maxlen         = sizeof(int),
 514                 .mode           = 0644,
 515                 .proc_handler   = proc_dointvec,
 516         },
 517 #endif
 518 #ifdef CONFIG_MODULES
 519         {
 520                 .procname       = "modprobe",
 521                 .data           = &modprobe_path,
 522                 .maxlen         = KMOD_PATH_LEN,
 523                 .mode           = 0644,
 524                 .proc_handler   = proc_dostring,
 525         },
 526         {
 527                 .procname       = "modules_disabled",
 528                 .data           = &modules_disabled,
 529                 .maxlen         = sizeof(int),
 530                 .mode           = 0644,
 531                 /* only handle a transition from default "0" to "1" */
 532                 .proc_handler   = proc_dointvec_minmax,
 533                 .extra1         = &one,
 534                 .extra2         = &one,
 535         },
 536 #endif
 537 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 538         {
 539                 .procname       = "hotplug",
 540                 .data           = &uevent_helper,
 541                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 542                 .mode           = 0644,
 543                 .proc_handler   = proc_dostring,
 544         },
 545 #endif
 546 #ifdef CONFIG_CHR_DEV_SG
 547         {
 548                 .procname       = "sg-big-buff",
 549                 .data           = &sg_big_buff,
 550                 .maxlen         = sizeof (int),
 551                 .mode           = 0444,
 552                 .proc_handler   = proc_dointvec,
 553         },
 554 #endif
 555 #ifdef CONFIG_BSD_PROCESS_ACCT
 556         {
 557                 .procname       = "acct",
 558                 .data           = &acct_parm,
 559                 .maxlen         = 3*sizeof(int),
 560                 .mode           = 0644,
 561                 .proc_handler   = proc_dointvec,
 562         },
 563 #endif
 564 #ifdef CONFIG_MAGIC_SYSRQ
 565         {
 566                 .procname       = "sysrq",
 567                 .data           = &__sysrq_enabled,
 568                 .maxlen         = sizeof (int),
 569                 .mode           = 0644,
 570                 .proc_handler   = proc_dointvec,
 571         },
 572 #endif
 573 #ifdef CONFIG_PROC_SYSCTL
 574         {
 575                 .procname       = "cad_pid",
 576                 .data           = NULL,
 577                 .maxlen         = sizeof (int),
 578                 .mode           = 0600,
 579                 .proc_handler   = proc_do_cad_pid,
 580         },
 581 #endif
 582         {
 583                 .procname       = "threads-max",
 584                 .data           = &max_threads,
 585                 .maxlen         = sizeof(int),
 586                 .mode           = 0644,
 587                 .proc_handler   = proc_dointvec,
 588         },
 589         {
 590                 .procname       = "random",
 591                 .mode           = 0555,
 592                 .child          = random_table,
 593         },
 594         {
 595                 .procname       = "overflowuid",
 596                 .data           = &overflowuid,
 597                 .maxlen         = sizeof(int),
 598                 .mode           = 0644,
 599                 .proc_handler   = proc_dointvec_minmax,
 600                 .extra1         = &minolduid,
 601                 .extra2         = &maxolduid,
 602         },
 603         {
 604                 .procname       = "overflowgid",
 605                 .data           = &overflowgid,
 606                 .maxlen         = sizeof(int),
 607                 .mode           = 0644,
 608                 .proc_handler   = proc_dointvec_minmax,
 609                 .extra1         = &minolduid,
 610                 .extra2         = &maxolduid,
 611         },
 612 #ifdef CONFIG_S390
 613 #ifdef CONFIG_MATHEMU
 614         {
 615                 .procname       = "ieee_emulation_warnings",
 616                 .data           = &sysctl_ieee_emulation_warnings,
 617                 .maxlen         = sizeof(int),
 618                 .mode           = 0644,
 619                 .proc_handler   = proc_dointvec,
 620         },
 621 #endif
 622         {
 623                 .procname       = "userprocess_debug",
 624                 .data           = &sysctl_userprocess_debug,
 625                 .maxlen         = sizeof(int),
 626                 .mode           = 0644,
 627                 .proc_handler   = proc_dointvec,
 628         },
 629 #endif
 630         {
 631                 .procname       = "pid_max",
 632                 .data           = &pid_max,
 633                 .maxlen         = sizeof (int),
 634                 .mode           = 0644,
 635                 .proc_handler   = proc_dointvec_minmax,
 636                 .extra1         = &pid_max_min,
 637                 .extra2         = &pid_max_max,
 638         },
 639         {
 640                 .procname       = "panic_on_oops",
 641                 .data           = &panic_on_oops,
 642                 .maxlen         = sizeof(int),
 643                 .mode           = 0644,
 644                 .proc_handler   = proc_dointvec,
 645         },
 646 #if defined CONFIG_PRINTK
 647         {
 648                 .procname       = "printk",
 649                 .data           = &console_loglevel,
 650                 .maxlen         = 4*sizeof(int),
 651                 .mode           = 0644,
 652                 .proc_handler   = proc_dointvec,
 653         },
 654         {
 655                 .procname       = "printk_ratelimit",
 656                 .data           = &printk_ratelimit_state.interval,
 657                 .maxlen         = sizeof(int),
 658                 .mode           = 0644,
 659                 .proc_handler   = proc_dointvec_jiffies,
 660         },
 661         {
 662                 .procname       = "printk_ratelimit_burst",
 663                 .data           = &printk_ratelimit_state.burst,
 664                 .maxlen         = sizeof(int),
 665                 .mode           = 0644,
 666                 .proc_handler   = proc_dointvec,
 667         },
 668         {
 669                 .procname       = "printk_delay",
 670                 .data           = &printk_delay_msec,
 671                 .maxlen         = sizeof(int),
 672                 .mode           = 0644,
 673                 .proc_handler   = proc_dointvec_minmax,
 674                 .extra1         = &zero,
 675                 .extra2         = &ten_thousand,
 676         },
 677 #endif
 678         {
 679                 .procname       = "ngroups_max",
 680                 .data           = &ngroups_max,
 681                 .maxlen         = sizeof (int),
 682                 .mode           = 0444,
 683                 .proc_handler   = proc_dointvec,
 684         },
 685 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 686         {
 687                 .procname       = "unknown_nmi_panic",
 688                 .data           = &unknown_nmi_panic,
 689                 .maxlen         = sizeof (int),
 690                 .mode           = 0644,
 691                 .proc_handler   = proc_dointvec,
 692         },
 693         {
 694                 .procname       = "nmi_watchdog",
 695                 .data           = &nmi_watchdog_enabled,
 696                 .maxlen         = sizeof (int),
 697                 .mode           = 0644,
 698                 .proc_handler   = proc_nmi_enabled,
 699         },
 700 #endif
 701 #if defined(CONFIG_X86)
 702         {
 703                 .procname       = "panic_on_unrecovered_nmi",
 704                 .data           = &panic_on_unrecovered_nmi,
 705                 .maxlen         = sizeof(int),
 706                 .mode           = 0644,
 707                 .proc_handler   = proc_dointvec,
 708         },
 709         {
 710                 .procname       = "panic_on_io_nmi",
 711                 .data           = &panic_on_io_nmi,
 712                 .maxlen         = sizeof(int),
 713                 .mode           = 0644,
 714                 .proc_handler   = proc_dointvec,
 715         },
 716         {
 717                 .procname       = "bootloader_type",
 718                 .data           = &bootloader_type,
 719                 .maxlen         = sizeof (int),
 720                 .mode           = 0444,
 721                 .proc_handler   = proc_dointvec,
 722         },
 723         {
 724                 .procname       = "bootloader_version",
 725                 .data           = &bootloader_version,
 726                 .maxlen         = sizeof (int),
 727                 .mode           = 0444,
 728                 .proc_handler   = proc_dointvec,
 729         },
 730         {
 731                 .procname       = "kstack_depth_to_print",
 732                 .data           = &kstack_depth_to_print,
 733                 .maxlen         = sizeof(int),
 734                 .mode           = 0644,
 735                 .proc_handler   = proc_dointvec,
 736         },
 737         {
 738                 .procname       = "io_delay_type",
 739                 .data           = &io_delay_type,
 740                 .maxlen         = sizeof(int),
 741                 .mode           = 0644,
 742                 .proc_handler   = proc_dointvec,
 743         },
 744 #endif
 745 #if defined(CONFIG_MMU)
 746         {
 747                 .procname       = "randomize_va_space",
 748                 .data           = &randomize_va_space,
 749                 .maxlen         = sizeof(int),
 750                 .mode           = 0644,
 751                 .proc_handler   = proc_dointvec,
 752         },
 753 #endif
 754 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 755         {
 756                 .procname       = "spin_retry",
 757                 .data           = &spin_retry,
 758                 .maxlen         = sizeof (int),
 759                 .mode           = 0644,
 760                 .proc_handler   = proc_dointvec,
 761         },
 762 #endif
 763 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 764         {
 765                 .procname       = "acpi_video_flags",
 766                 .data           = &acpi_realmode_flags,
 767                 .maxlen         = sizeof (unsigned long),
 768                 .mode           = 0644,
 769                 .proc_handler   = proc_doulongvec_minmax,
 770         },
 771 #endif
 772 #ifdef CONFIG_IA64
 773         {
 774                 .procname       = "ignore-unaligned-usertrap",
 775                 .data           = &no_unaligned_warning,
 776                 .maxlen         = sizeof (int),
 777                 .mode           = 0644,
 778                 .proc_handler   = proc_dointvec,
 779         },
 780         {
 781                 .procname       = "unaligned-dump-stack",
 782                 .data           = &unaligned_dump_stack,
 783                 .maxlen         = sizeof (int),
 784                 .mode           = 0644,
 785                 .proc_handler   = proc_dointvec,
 786         },
 787 #endif
 788 #ifdef CONFIG_DETECT_SOFTLOCKUP
 789         {
 790                 .procname       = "softlockup_panic",
 791                 .data           = &softlockup_panic,
 792                 .maxlen         = sizeof(int),
 793                 .mode           = 0644,
 794                 .proc_handler   = proc_dointvec_minmax,
 795                 .extra1         = &zero,
 796                 .extra2         = &one,
 797         },
 798         {
 799                 .procname       = "softlockup_thresh",
 800                 .data           = &softlockup_thresh,
 801                 .maxlen         = sizeof(int),
 802                 .mode           = 0644,
 803                 .proc_handler   = proc_dosoftlockup_thresh,
 804                 .extra1         = &neg_one,
 805                 .extra2         = &sixty,
 806         },
 807 #endif
 808 #ifdef CONFIG_DETECT_HUNG_TASK
 809         {
 810                 .procname       = "hung_task_panic",
 811                 .data           = &sysctl_hung_task_panic,
 812                 .maxlen         = sizeof(int),
 813                 .mode           = 0644,
 814                 .proc_handler   = proc_dointvec_minmax,
 815                 .extra1         = &zero,
 816                 .extra2         = &one,
 817         },
 818         {
 819                 .procname       = "hung_task_check_count",
 820                 .data           = &sysctl_hung_task_check_count,
 821                 .maxlen         = sizeof(unsigned long),
 822                 .mode           = 0644,
 823                 .proc_handler   = proc_doulongvec_minmax,
 824         },
 825         {
 826                 .procname       = "hung_task_timeout_secs",
 827                 .data           = &sysctl_hung_task_timeout_secs,
 828                 .maxlen         = sizeof(unsigned long),
 829                 .mode           = 0644,
 830                 .proc_handler   = proc_dohung_task_timeout_secs,
 831         },
 832         {
 833                 .procname       = "hung_task_warnings",
 834                 .data           = &sysctl_hung_task_warnings,
 835                 .maxlen         = sizeof(unsigned long),
 836                 .mode           = 0644,
 837                 .proc_handler   = proc_doulongvec_minmax,
 838         },
 839 #endif
 840 #ifdef CONFIG_COMPAT
 841         {
 842                 .procname       = "compat-log",
 843                 .data           = &compat_log,
 844                 .maxlen         = sizeof (int),
 845                 .mode           = 0644,
 846                 .proc_handler   = proc_dointvec,
 847         },
 848 #endif
 849 #ifdef CONFIG_RT_MUTEXES
 850         {
 851                 .procname       = "max_lock_depth",
 852                 .data           = &max_lock_depth,
 853                 .maxlen         = sizeof(int),
 854                 .mode           = 0644,
 855                 .proc_handler   = proc_dointvec,
 856         },
 857 #endif
 858         {
 859                 .procname       = "poweroff_cmd",
 860                 .data           = &poweroff_cmd,
 861                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 862                 .mode           = 0644,
 863                 .proc_handler   = proc_dostring,
 864         },
 865 #ifdef CONFIG_KEYS
 866         {
 867                 .procname       = "keys",
 868                 .mode           = 0555,
 869                 .child          = key_sysctls,
 870         },
 871 #endif
 872 #ifdef CONFIG_RCU_TORTURE_TEST
 873         {
 874                 .procname       = "rcutorture_runnable",
 875                 .data           = &rcutorture_runnable,
 876                 .maxlen         = sizeof(int),
 877                 .mode           = 0644,
 878                 .proc_handler   = proc_dointvec,
 879         },
 880 #endif
 881 #ifdef CONFIG_SLOW_WORK
 882         {
 883                 .procname       = "slow-work",
 884                 .mode           = 0555,
 885                 .child          = slow_work_sysctls,
 886         },
 887 #endif
 888 #ifdef CONFIG_PERF_EVENTS
 889         {
 890                 .procname       = "perf_event_paranoid",
 891                 .data           = &sysctl_perf_event_paranoid,
 892                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 893                 .mode           = 0644,
 894                 .proc_handler   = proc_dointvec,
 895         },
 896         {
 897                 .procname       = "perf_event_mlock_kb",
 898                 .data           = &sysctl_perf_event_mlock,
 899                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 900                 .mode           = 0644,
 901                 .proc_handler   = proc_dointvec,
 902         },
 903         {
 904                 .procname       = "perf_event_max_sample_rate",
 905                 .data           = &sysctl_perf_event_sample_rate,
 906                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 907                 .mode           = 0644,
 908                 .proc_handler   = proc_dointvec,
 909         },
 910 #endif
 911 #ifdef CONFIG_KMEMCHECK
 912         {
 913                 .procname       = "kmemcheck",
 914                 .data           = &kmemcheck_enabled,
 915                 .maxlen         = sizeof(int),
 916                 .mode           = 0644,
 917                 .proc_handler   = proc_dointvec,
 918         },
 919 #endif
 920 #ifdef CONFIG_BLOCK
 921         {
 922                 .procname       = "blk_iopoll",
 923                 .data           = &blk_iopoll_enabled,
 924                 .maxlen         = sizeof(int),
 925                 .mode           = 0644,
 926                 .proc_handler   = proc_dointvec,
 927         },
 928 #endif
 929 /*
 930  * NOTE: do not add new entries to this table unless you have read
 931  * Documentation/sysctl/ctl_unnumbered.txt
 932  */
 933         { }
 934 };
 935
 936 static struct ctl_table vm_table[] = {
 937         {
 938                 .procname       = "overcommit_memory",
 939                 .data           = &sysctl_overcommit_memory,
 940                 .maxlen         = sizeof(sysctl_overcommit_memory),
 941                 .mode           = 0644,
 942                 .proc_handler   = proc_dointvec,
 943         },
 944         {
 945                 .procname       = "panic_on_oom",
 946                 .data           = &sysctl_panic_on_oom,
 947                 .maxlen         = sizeof(sysctl_panic_on_oom),
 948                 .mode           = 0644,
 949                 .proc_handler   = proc_dointvec,
 950         },
 951         {
 952                 .procname       = "oom_kill_allocating_task",
 953                 .data           = &sysctl_oom_kill_allocating_task,
 954                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 955                 .mode           = 0644,
 956                 .proc_handler   = proc_dointvec,
 957         },
 958         {
 959                 .procname       = "oom_dump_tasks",
 960                 .data           = &sysctl_oom_dump_tasks,
 961                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 962                 .mode           = 0644,
 963                 .proc_handler   = proc_dointvec,
 964         },
 965         {
 966                 .procname       = "overcommit_ratio",
 967                 .data           = &sysctl_overcommit_ratio,
 968                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 969                 .mode           = 0644,
 970                 .proc_handler   = proc_dointvec,
 971         },
 972         {
 973                 .procname       = "page-cluster",
 974                 .data           = &page_cluster,
 975                 .maxlen         = sizeof(int),
 976                 .mode           = 0644,
 977                 .proc_handler   = proc_dointvec,
 978         },
 979         {
 980                 .procname       = "dirty_background_ratio",
 981                 .data           = &dirty_background_ratio,
 982                 .maxlen         = sizeof(dirty_background_ratio),
 983                 .mode           = 0644,
 984                 .proc_handler   = dirty_background_ratio_handler,
 985                 .extra1         = &zero,
 986                 .extra2         = &one_hundred,
 987         },
 988         {
 989                 .procname       = "dirty_background_bytes",
 990                 .data           = &dirty_background_bytes,
 991                 .maxlen         = sizeof(dirty_background_bytes),
 992                 .mode           = 0644,
 993                 .proc_handler   = dirty_background_bytes_handler,
 994                 .extra1         = &one_ul,
 995         },
 996         {
 997                 .procname       = "dirty_ratio",
 998                 .data           = &vm_dirty_ratio,
 999                 .maxlen         = sizeof(vm_dirty_ratio),
1000                 .mode           = 0644,
1001                 .proc_handler   = dirty_ratio_handler,
1002                 .extra1         = &zero,
1003                 .extra2         = &one_hundred,
1004         },
1005         {
1006                 .procname       = "dirty_bytes",
1007                 .data           = &vm_dirty_bytes,
1008                 .maxlen         = sizeof(vm_dirty_bytes),
1009                 .mode           = 0644,
1010                 .proc_handler   = dirty_bytes_handler,
1011                 .extra1         = &dirty_bytes_min,
1012         },
1013         {
1014                 .procname       = "dirty_writeback_centisecs",
1015                 .data           = &dirty_writeback_interval,
1016                 .maxlen         = sizeof(dirty_writeback_interval),
1017                 .mode           = 0644,
1018                 .proc_handler   = dirty_writeback_centisecs_handler,
1019         },
1020         {
1021                 .procname       = "dirty_expire_centisecs",
1022                 .data           = &dirty_expire_interval,
1023                 .maxlen         = sizeof(dirty_expire_interval),
1024                 .mode           = 0644,
1025                 .proc_handler   = proc_dointvec,
1026         },
1027         {
1028                 .procname       = "nr_pdflush_threads",
1029                 .data           = &nr_pdflush_threads,
1030                 .maxlen         = sizeof nr_pdflush_threads,
1031                 .mode           = 0444 /* read-only*/,
1032                 .proc_handler   = proc_dointvec,
1033         },
1034         {
1035                 .procname       = "swappiness",
1036                 .data           = &vm_swappiness,
1037                 .maxlen         = sizeof(vm_swappiness),
1038                 .mode           = 0644,
1039                 .proc_handler   = proc_dointvec_minmax,
1040                 .extra1         = &zero,
1041                 .extra2         = &one_hundred,
1042         },
1043 #ifdef CONFIG_HUGETLB_PAGE
1044         {
1045                 .procname       = "nr_hugepages",
1046                 .data           = NULL,
1047                 .maxlen         = sizeof(unsigned long),
1048                 .mode           = 0644,
1049                 .proc_handler   = hugetlb_sysctl_handler,
1050                 .extra1         = (void *)&hugetlb_zero,
1051                 .extra2         = (void *)&hugetlb_infinity,
1052         },
1053 #ifdef CONFIG_NUMA
1054         {
1055                 .procname       = "nr_hugepages_mempolicy",
1056                 .data           = NULL,
1057                 .maxlen         = sizeof(unsigned long),
1058                 .mode           = 0644,
1059                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1060                 .extra1         = (void *)&hugetlb_zero,
1061                 .extra2         = (void *)&hugetlb_infinity,
1062         },
1063 #endif
1064          {
1065                 .procname       = "hugetlb_shm_group",
1066                 .data           = &sysctl_hugetlb_shm_group,
1067                 .maxlen         = sizeof(gid_t),
1068                 .mode           = 0644,
1069                 .proc_handler   = proc_dointvec,
1070          },
1071          {
1072                 .procname       = "hugepages_treat_as_movable",
1073                 .data           = &hugepages_treat_as_movable,
1074                 .maxlen         = sizeof(int),
1075                 .mode           = 0644,
1076                 .proc_handler   = hugetlb_treat_movable_handler,
1077         },
1078         {
1079                 .procname       = "nr_overcommit_hugepages",
1080                 .data           = NULL,
1081                 .maxlen         = sizeof(unsigned long),
1082                 .mode           = 0644,
1083                 .proc_handler   = hugetlb_overcommit_handler,
1084                 .extra1         = (void *)&hugetlb_zero,
1085                 .extra2         = (void *)&hugetlb_infinity,
1086         },
1087 #endif
1088         {
1089                 .procname       = "lowmem_reserve_ratio",
1090                 .data           = &sysctl_lowmem_reserve_ratio,
1091                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1092                 .mode           = 0644,
1093                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1094         },
1095         {
1096                 .procname       = "drop_caches",
1097                 .data           = &sysctl_drop_caches,
1098                 .maxlen         = sizeof(int),
1099                 .mode           = 0644,
1100                 .proc_handler   = drop_caches_sysctl_handler,
1101         },
1102         {
1103                 .procname       = "min_free_kbytes",
1104                 .data           = &min_free_kbytes,
1105                 .maxlen         = sizeof(min_free_kbytes),
1106                 .mode           = 0644,
1107                 .proc_handler   = min_free_kbytes_sysctl_handler,
1108                 .extra1         = &zero,
1109         },
1110         {
1111                 .procname       = "percpu_pagelist_fraction",
1112                 .data           = &percpu_pagelist_fraction,
1113                 .maxlen         = sizeof(percpu_pagelist_fraction),
1114                 .mode           = 0644,
1115                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1116                 .extra1         = &min_percpu_pagelist_fract,
1117         },
1118 #ifdef CONFIG_MMU
1119         {
1120                 .procname       = "max_map_count",
1121                 .data           = &sysctl_max_map_count,
1122                 .maxlen         = sizeof(sysctl_max_map_count),
1123                 .mode           = 0644,
1124                 .proc_handler   = proc_dointvec_minmax,
1125                 .extra1         = &zero,
1126         },
1127 #else
1128         {
1129                 .procname       = "nr_trim_pages",
1130                 .data           = &sysctl_nr_trim_pages,
1131                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1132                 .mode           = 0644,
1133                 .proc_handler   = proc_dointvec_minmax,
1134                 .extra1         = &zero,
1135         },
1136 #endif
1137         {
1138                 .procname       = "laptop_mode",
1139                 .data           = &laptop_mode,
1140                 .maxlen         = sizeof(laptop_mode),
1141                 .mode           = 0644,
1142                 .proc_handler   = proc_dointvec_jiffies,
1143         },
1144         {
1145                 .procname       = "block_dump",
1146                 .data           = &block_dump,
1147                 .maxlen         = sizeof(block_dump),
1148                 .mode           = 0644,
1149                 .proc_handler   = proc_dointvec,
1150                 .extra1         = &zero,
1151         },
1152         {
1153                 .procname       = "vfs_cache_pressure",
1154                 .data           = &sysctl_vfs_cache_pressure,
1155                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1156                 .mode           = 0644,
1157                 .proc_handler   = proc_dointvec,
1158                 .extra1         = &zero,
1159         },
1160 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1161         {
1162                 .procname       = "legacy_va_layout",
1163                 .data           = &sysctl_legacy_va_layout,
1164                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1165                 .mode           = 0644,
1166                 .proc_handler   = proc_dointvec,
1167                 .extra1         = &zero,
1168         },
1169 #endif
1170 #ifdef CONFIG_NUMA
1171         {
1172                 .procname       = "zone_reclaim_mode",
1173                 .data           = &zone_reclaim_mode,
1174                 .maxlen         = sizeof(zone_reclaim_mode),
1175                 .mode           = 0644,
1176                 .proc_handler   = proc_dointvec,
1177                 .extra1         = &zero,
1178         },
1179         {
1180                 .procname       = "min_unmapped_ratio",
1181                 .data           = &sysctl_min_unmapped_ratio,
1182                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1183                 .mode           = 0644,
1184                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1185                 .extra1         = &zero,
1186                 .extra2         = &one_hundred,
1187         },
1188         {
1189                 .procname       = "min_slab_ratio",
1190                 .data           = &sysctl_min_slab_ratio,
1191                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1192                 .mode           = 0644,
1193                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1194                 .extra1         = &zero,
1195                 .extra2         = &one_hundred,
1196         },
1197 #endif
1198 #ifdef CONFIG_SMP
1199         {
1200                 .procname       = "stat_interval",
1201                 .data           = &sysctl_stat_interval,
1202                 .maxlen         = sizeof(sysctl_stat_interval),
1203                 .mode           = 0644,
1204                 .proc_handler   = proc_dointvec_jiffies,
1205         },
1206 #endif
1207 #ifdef CONFIG_MMU
1208         {
1209                 .procname       = "mmap_min_addr",
1210                 .data           = &dac_mmap_min_addr,
1211                 .maxlen         = sizeof(unsigned long),
1212                 .mode           = 0644,
1213                 .proc_handler   = mmap_min_addr_handler,
1214         },
1215 #endif
1216 #ifdef CONFIG_NUMA
1217         {
1218                 .procname       = "numa_zonelist_order",
1219                 .data           = &numa_zonelist_order,
1220                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1221                 .mode           = 0644,
1222                 .proc_handler   = numa_zonelist_order_handler,
1223         },
1224 #endif
1225 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1226    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1227         {
1228                 .procname       = "vdso_enabled",
1229                 .data           = &vdso_enabled,
1230                 .maxlen         = sizeof(vdso_enabled),
1231                 .mode           = 0644,
1232                 .proc_handler   = proc_dointvec,
1233                 .extra1         = &zero,
1234         },
1235 #endif
1236 #ifdef CONFIG_HIGHMEM
1237         {
1238                 .procname       = "highmem_is_dirtyable",
1239                 .data           = &vm_highmem_is_dirtyable,
1240                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1241                 .mode           = 0644,
1242                 .proc_handler   = proc_dointvec_minmax,
1243                 .extra1         = &zero,
1244                 .extra2         = &one,
1245         },
1246 #endif
1247         {
1248                 .procname       = "scan_unevictable_pages",
1249                 .data           = &scan_unevictable_pages,
1250                 .maxlen         = sizeof(scan_unevictable_pages),
1251                 .mode           = 0644,
1252                 .proc_handler   = scan_unevictable_handler,
1253         },
1254 #ifdef CONFIG_MEMORY_FAILURE
1255         {
1256                 .procname       = "memory_failure_early_kill",
1257                 .data           = &sysctl_memory_failure_early_kill,
1258                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1259                 .mode           = 0644,
1260                 .proc_handler   = proc_dointvec_minmax,
1261                 .extra1         = &zero,
1262                 .extra2         = &one,
1263         },
1264         {
1265                 .procname       = "memory_failure_recovery",
1266                 .data           = &sysctl_memory_failure_recovery,
1267                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1268                 .mode           = 0644,
1269                 .proc_handler   = proc_dointvec_minmax,
1270                 .extra1         = &zero,
1271                 .extra2         = &one,
1272         },
1273 #endif
1274
1275 /*
1276  * NOTE: do not add new entries to this table unless you have read
1277  * Documentation/sysctl/ctl_unnumbered.txt
1278  */
1279         { }
1280 };
1281
1282 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1283 static struct ctl_table binfmt_misc_table[] = {
1284         { }
1285 };
1286 #endif
1287
1288 static struct ctl_table fs_table[] = {
1289         {
1290                 .procname       = "inode-nr",
1291                 .data           = &inodes_stat,
1292                 .maxlen         = 2*sizeof(int),
1293                 .mode           = 0444,
1294                 .proc_handler   = proc_dointvec,
1295         },
1296         {
1297                 .procname       = "inode-state",
1298                 .data           = &inodes_stat,
1299                 .maxlen         = 7*sizeof(int),
1300                 .mode           = 0444,
1301                 .proc_handler   = proc_dointvec,
1302         },
1303         {
1304                 .procname       = "file-nr",
1305                 .data           = &files_stat,
1306                 .maxlen         = 3*sizeof(int),
1307                 .mode           = 0444,
1308                 .proc_handler   = proc_nr_files,
1309         },
1310         {
1311                 .procname       = "file-max",
1312                 .data           = &files_stat.max_files,
1313                 .maxlen         = sizeof(int),
1314                 .mode           = 0644,
1315                 .proc_handler   = proc_dointvec,
1316         },
1317         {
1318                 .procname       = "nr_open",
1319                 .data           = &sysctl_nr_open,
1320                 .maxlen         = sizeof(int),
1321                 .mode           = 0644,
1322                 .proc_handler   = proc_dointvec_minmax,
1323                 .extra1         = &sysctl_nr_open_min,
1324                 .extra2         = &sysctl_nr_open_max,
1325         },
1326         {
1327                 .procname       = "dentry-state",
1328                 .data           = &dentry_stat,
1329                 .maxlen         = 6*sizeof(int),
1330                 .mode           = 0444,
1331                 .proc_handler   = proc_dointvec,
1332         },
1333         {
1334                 .procname       = "overflowuid",
1335                 .data           = &fs_overflowuid,
1336                 .maxlen         = sizeof(int),
1337                 .mode           = 0644,
1338                 .proc_handler   = proc_dointvec_minmax,
1339                 .extra1         = &minolduid,
1340                 .extra2         = &maxolduid,
1341         },
1342         {
1343                 .procname       = "overflowgid",
1344                 .data           = &fs_overflowgid,
1345                 .maxlen         = sizeof(int),
1346                 .mode           = 0644,
1347                 .proc_handler   = proc_dointvec_minmax,
1348                 .extra1         = &minolduid,
1349                 .extra2         = &maxolduid,
1350         },
1351 #ifdef CONFIG_FILE_LOCKING
1352         {
1353                 .procname       = "leases-enable",
1354                 .data           = &leases_enable,
1355                 .maxlen         = sizeof(int),
1356                 .mode           = 0644,
1357                 .proc_handler   = proc_dointvec,
1358         },
1359 #endif
1360 #ifdef CONFIG_DNOTIFY
1361         {
1362                 .procname       = "dir-notify-enable",
1363                 .data           = &dir_notify_enable,
1364                 .maxlen         = sizeof(int),
1365                 .mode           = 0644,
1366                 .proc_handler   = proc_dointvec,
1367         },
1368 #endif
1369 #ifdef CONFIG_MMU
1370 #ifdef CONFIG_FILE_LOCKING
1371         {
1372                 .procname       = "lease-break-time",
1373                 .data           = &lease_break_time,
1374                 .maxlen         = sizeof(int),
1375                 .mode           = 0644,
1376                 .proc_handler   = proc_dointvec,
1377         },
1378 #endif
1379 #ifdef CONFIG_AIO
1380         {
1381                 .procname       = "aio-nr",
1382                 .data           = &aio_nr,
1383                 .maxlen         = sizeof(aio_nr),
1384                 .mode           = 0444,
1385                 .proc_handler   = proc_doulongvec_minmax,
1386         },
1387         {
1388                 .procname       = "aio-max-nr",
1389                 .data           = &aio_max_nr,
1390                 .maxlen         = sizeof(aio_max_nr),
1391                 .mode           = 0644,
1392                 .proc_handler   = proc_doulongvec_minmax,
1393         },
1394 #endif /* CONFIG_AIO */
1395 #ifdef CONFIG_INOTIFY_USER
1396         {
1397                 .procname       = "inotify",
1398                 .mode           = 0555,
1399                 .child          = inotify_table,
1400         },
1401 #endif
1402 #ifdef CONFIG_EPOLL
1403         {
1404                 .procname       = "epoll",
1405                 .mode           = 0555,
1406                 .child          = epoll_table,
1407         },
1408 #endif
1409 #endif
1410         {
1411                 .procname       = "suid_dumpable",
1412                 .data           = &suid_dumpable,
1413                 .maxlen         = sizeof(int),
1414                 .mode           = 0644,
1415                 .proc_handler   = proc_dointvec_minmax,
1416                 .extra1         = &zero,
1417                 .extra2         = &two,
1418         },
1419 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1420         {
1421                 .procname       = "binfmt_misc",
1422                 .mode           = 0555,
1423                 .child          = binfmt_misc_table,
1424         },
1425 #endif
1426 /*
1427  * NOTE: do not add new entries to this table unless you have read
1428  * Documentation/sysctl/ctl_unnumbered.txt
1429  */
1430         { }
1431 };
1432
1433 static struct ctl_table debug_table[] = {
1434 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC)
1435         {
1436                 .procname       = "exception-trace",
1437                 .data           = &show_unhandled_signals,
1438                 .maxlen         = sizeof(int),
1439                 .mode           = 0644,
1440                 .proc_handler   = proc_dointvec
1441         },
1442 #endif
1443 #if defined(CONFIG_OPTPROBES)
1444         {
1445                 .procname       = "kprobes-optimization",
1446                 .data           = &sysctl_kprobes_optimization,
1447                 .maxlen         = sizeof(int),
1448                 .mode           = 0644,
1449                 .proc_handler   = proc_kprobes_optimization_handler,
1450                 .extra1         = &zero,
1451                 .extra2         = &one,
1452         },
1453 #endif
1454         { }
1455 };
1456
1457 static struct ctl_table dev_table[] = {
1458         { }
1459 };
1460
1461 static DEFINE_SPINLOCK(sysctl_lock);
1462
1463 /* called under sysctl_lock */
1464 static int use_table(struct ctl_table_header *p)
1465 {
1466         if (unlikely(p->unregistering))
1467                 return 0;
1468         p->used++;
1469         return 1;
1470 }
1471
1472 /* called under sysctl_lock */
1473 static void unuse_table(struct ctl_table_header *p)
1474 {
1475         if (!--p->used)
1476                 if (unlikely(p->unregistering))
1477                         complete(p->unregistering);
1478 }
1479
1480 /* called under sysctl_lock, will reacquire if has to wait */
1481 static void start_unregistering(struct ctl_table_header *p)
1482 {
1483         /*
1484          * if p->used is 0, nobody will ever touch that entry again;
1485          * we'll eliminate all paths to it before dropping sysctl_lock
1486          */
1487         if (unlikely(p->used)) {
1488                 struct completion wait;
1489                 init_completion(&wait);
1490                 p->unregistering = &wait;
1491                 spin_unlock(&sysctl_lock);
1492                 wait_for_completion(&wait);
1493                 spin_lock(&sysctl_lock);
1494         } else {
1495                 /* anything non-NULL; we'll never dereference it */
1496                 p->unregistering = ERR_PTR(-EINVAL);
1497         }
1498         /*
1499          * do not remove from the list until nobody holds it; walking the
1500          * list in do_sysctl() relies on that.
1501          */
1502         list_del_init(&p->ctl_entry);
1503 }
1504
1505 void sysctl_head_get(struct ctl_table_header *head)
1506 {
1507         spin_lock(&sysctl_lock);
1508         head->count++;
1509         spin_unlock(&sysctl_lock);
1510 }
1511
1512 void sysctl_head_put(struct ctl_table_header *head)
1513 {
1514         spin_lock(&sysctl_lock);
1515         if (!--head->count)
1516                 kfree(head);
1517         spin_unlock(&sysctl_lock);
1518 }
1519
1520 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1521 {
1522         if (!head)
1523                 BUG();
1524         spin_lock(&sysctl_lock);
1525         if (!use_table(head))
1526                 head = ERR_PTR(-ENOENT);
1527         spin_unlock(&sysctl_lock);
1528         return head;
1529 }
1530
1531 void sysctl_head_finish(struct ctl_table_header *head)
1532 {
1533         if (!head)
1534                 return;
1535         spin_lock(&sysctl_lock);
1536         unuse_table(head);
1537         spin_unlock(&sysctl_lock);
1538 }
1539
1540 static struct ctl_table_set *
1541 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1542 {
1543         struct ctl_table_set *set = &root->default_set;
1544         if (root->lookup)
1545                 set = root->lookup(root, namespaces);
1546         return set;
1547 }
1548
1549 static struct list_head *
1550 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1551 {
1552         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1553         return &set->list;
1554 }
1555
1556 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1557                                             struct ctl_table_header *prev)
1558 {
1559         struct ctl_table_root *root;
1560         struct list_head *header_list;
1561         struct ctl_table_header *head;
1562         struct list_head *tmp;
1563
1564         spin_lock(&sysctl_lock);
1565         if (prev) {
1566                 head = prev;
1567                 tmp = &prev->ctl_entry;
1568                 unuse_table(prev);
1569                 goto next;
1570         }
1571         tmp = &root_table_header.ctl_entry;
1572         for (;;) {
1573                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1574
1575                 if (!use_table(head))
1576                         goto next;
1577                 spin_unlock(&sysctl_lock);
1578                 return head;
1579         next:
1580                 root = head->root;
1581                 tmp = tmp->next;
1582                 header_list = lookup_header_list(root, namespaces);
1583                 if (tmp != header_list)
1584                         continue;
1585
1586                 do {
1587                         root = list_entry(root->root_list.next,
1588                                         struct ctl_table_root, root_list);
1589                         if (root == &sysctl_table_root)
1590                                 goto out;
1591                         header_list = lookup_header_list(root, namespaces);
1592                 } while (list_empty(header_list));
1593                 tmp = header_list->next;
1594         }
1595 out:
1596         spin_unlock(&sysctl_lock);
1597         return NULL;
1598 }
1599
1600 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1601 {
1602         return __sysctl_head_next(current->nsproxy, prev);
1603 }
1604
1605 void register_sysctl_root(struct ctl_table_root *root)
1606 {
1607         spin_lock(&sysctl_lock);
1608         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1609         spin_unlock(&sysctl_lock);
1610 }
1611
1612 /*
1613  * sysctl_perm does NOT grant the superuser all rights automatically, because
1614  * some sysctl variables are readonly even to root.
1615  */
1616
1617 static int test_perm(int mode, int op)
1618 {
1619         if (!current_euid())
1620                 mode >>= 6;
1621         else if (in_egroup_p(0))
1622                 mode >>= 3;
1623         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1624                 return 0;
1625         return -EACCES;
1626 }
1627
1628 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1629 {
1630         int error;
1631         int mode;
1632
1633         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1634         if (error)
1635                 return error;
1636
1637         if (root->permissions)
1638                 mode = root->permissions(root, current->nsproxy, table);
1639         else
1640                 mode = table->mode;
1641
1642         return test_perm(mode, op);
1643 }
1644
1645 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1646 {
1647         for (; table->procname; table++) {
1648                 table->parent = parent;
1649                 if (table->child)
1650                         sysctl_set_parent(table, table->child);
1651         }
1652 }
1653
1654 static __init int sysctl_init(void)
1655 {
1656         sysctl_set_parent(NULL, root_table);
1657 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1658         {
1659                 int err;
1660                 err = sysctl_check_table(current->nsproxy, root_table);
1661         }
1662 #endif
1663         return 0;
1664 }
1665
1666 core_initcall(sysctl_init);
1667
1668 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1669                                       struct ctl_table *table)
1670 {
1671         struct ctl_table *p;
1672         const char *s = branch->procname;
1673
1674         /* branch should have named subdirectory as its first element */
1675         if (!s || !branch->child)
1676                 return NULL;
1677
1678         /* ... and nothing else */
1679         if (branch[1].procname)
1680                 return NULL;
1681
1682         /* table should contain subdirectory with the same name */
1683         for (p = table; p->procname; p++) {
1684                 if (!p->child)
1685                         continue;
1686                 if (p->procname && strcmp(p->procname, s) == 0)
1687                         return p;
1688         }
1689         return NULL;
1690 }
1691
1692 /* see if attaching q to p would be an improvement */
1693 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1694 {
1695         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1696         struct ctl_table *next;
1697         int is_better = 0;
1698         int not_in_parent = !p->attached_by;
1699
1700         while ((next = is_branch_in(by, to)) != NULL) {
1701                 if (by == q->attached_by)
1702                         is_better = 1;
1703                 if (to == p->attached_by)
1704                         not_in_parent = 1;
1705                 by = by->child;
1706                 to = next->child;
1707         }
1708
1709         if (is_better && not_in_parent) {
1710                 q->attached_by = by;
1711                 q->attached_to = to;
1712                 q->parent = p;
1713         }
1714 }
1715
1716 /**
1717  * __register_sysctl_paths - register a sysctl hierarchy
1718  * @root: List of sysctl headers to register on
1719  * @namespaces: Data to compute which lists of sysctl entries are visible
1720  * @path: The path to the directory the sysctl table is in.
1721  * @table: the top-level table structure
1722  *
1723  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1724  * array. A completely 0 filled entry terminates the table.
1725  *
1726  * The members of the &struct ctl_table structure are used as follows:
1727  *
1728  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1729  *            enter a sysctl file
1730  *
1731  * data - a pointer to data for use by proc_handler
1732  *
1733  * maxlen - the maximum size in bytes of the data
1734  *
1735  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1736  *
1737  * child - a pointer to the child sysctl table if this entry is a directory, or
1738  *         %NULL.
1739  *
1740  * proc_handler - the text handler routine (described below)
1741  *
1742  * de - for internal use by the sysctl routines
1743  *
1744  * extra1, extra2 - extra pointers usable by the proc handler routines
1745  *
1746  * Leaf nodes in the sysctl tree will be represented by a single file
1747  * under /proc; non-leaf nodes will be represented by directories.
1748  *
1749  * sysctl(2) can automatically manage read and write requests through
1750  * the sysctl table.  The data and maxlen fields of the ctl_table
1751  * struct enable minimal validation of the values being written to be
1752  * performed, and the mode field allows minimal authentication.
1753  *
1754  * There must be a proc_handler routine for any terminal nodes
1755  * mirrored under /proc/sys (non-terminals are handled by a built-in
1756  * directory handler).  Several default handlers are available to
1757  * cover common cases -
1758  *
1759  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1760  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1761  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1762  *
1763  * It is the handler's job to read the input buffer from user memory
1764  * and process it. The handler should return 0 on success.
1765  *
1766  * This routine returns %NULL on a failure to register, and a pointer
1767  * to the table header on success.
1768  */
1769 struct ctl_table_header *__register_sysctl_paths(
1770         struct ctl_table_root *root,
1771         struct nsproxy *namespaces,
1772         const struct ctl_path *path, struct ctl_table *table)
1773 {
1774         struct ctl_table_header *header;
1775         struct ctl_table *new, **prevp;
1776         unsigned int n, npath;
1777         struct ctl_table_set *set;
1778
1779         /* Count the path components */
1780         for (npath = 0; path[npath].procname; ++npath)
1781                 ;
1782
1783         /*
1784          * For each path component, allocate a 2-element ctl_table array.
1785          * The first array element will be filled with the sysctl entry
1786          * for this, the second will be the sentinel (procname == 0).
1787          *
1788          * We allocate everything in one go so that we don't have to
1789          * worry about freeing additional memory in unregister_sysctl_table.
1790          */
1791         header = kzalloc(sizeof(struct ctl_table_header) +
1792                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1793         if (!header)
1794                 return NULL;
1795
1796         new = (struct ctl_table *) (header + 1);
1797
1798         /* Now connect the dots */
1799         prevp = &header->ctl_table;
1800         for (n = 0; n < npath; ++n, ++path) {
1801                 /* Copy the procname */
1802                 new->procname = path->procname;
1803                 new->mode     = 0555;
1804
1805                 *prevp = new;
1806                 prevp = &new->child;
1807
1808                 new += 2;
1809         }
1810         *prevp = table;
1811         header->ctl_table_arg = table;
1812
1813         INIT_LIST_HEAD(&header->ctl_entry);
1814         header->used = 0;
1815         header->unregistering = NULL;
1816         header->root = root;
1817         sysctl_set_parent(NULL, header->ctl_table);
1818         header->count = 1;
1819 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1820         if (sysctl_check_table(namespaces, header->ctl_table)) {
1821                 kfree(header);
1822                 return NULL;
1823         }
1824 #endif
1825         spin_lock(&sysctl_lock);
1826         header->set = lookup_header_set(root, namespaces);
1827         header->attached_by = header->ctl_table;
1828         header->attached_to = root_table;
1829         header->parent = &root_table_header;
1830         for (set = header->set; set; set = set->parent) {
1831                 struct ctl_table_header *p;
1832                 list_for_each_entry(p, &set->list, ctl_entry) {
1833                         if (p->unregistering)
1834                                 continue;
1835                         try_attach(p, header);
1836                 }
1837         }
1838         header->parent->count++;
1839         list_add_tail(&header->ctl_entry, &header->set->list);
1840         spin_unlock(&sysctl_lock);
1841
1842         return header;
1843 }
1844
1845 /**
1846  * register_sysctl_table_path - register a sysctl table hierarchy
1847  * @path: The path to the directory the sysctl table is in.
1848  * @table: the top-level table structure
1849  *
1850  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1851  * array. A completely 0 filled entry terminates the table.
1852  *
1853  * See __register_sysctl_paths for more details.
1854  */
1855 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1856                                                 struct ctl_table *table)
1857 {
1858         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1859                                         path, table);
1860 }
1861
1862 /**
1863  * register_sysctl_table - register a sysctl table hierarchy
1864  * @table: the top-level table structure
1865  *
1866  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1867  * array. A completely 0 filled entry terminates the table.
1868  *
1869  * See register_sysctl_paths for more details.
1870  */
1871 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1872 {
1873         static const struct ctl_path null_path[] = { {} };
1874
1875         return register_sysctl_paths(null_path, table);
1876 }
1877
1878 /**
1879  * unregister_sysctl_table - unregister a sysctl table hierarchy
1880  * @header: the header returned from register_sysctl_table
1881  *
1882  * Unregisters the sysctl table and all children. proc entries may not
1883  * actually be removed until they are no longer used by anyone.
1884  */
1885 void unregister_sysctl_table(struct ctl_table_header * header)
1886 {
1887         might_sleep();
1888
1889         if (header == NULL)
1890                 return;
1891
1892         spin_lock(&sysctl_lock);
1893         start_unregistering(header);
1894         if (!--header->parent->count) {
1895                 WARN_ON(1);
1896                 kfree(header->parent);
1897         }
1898         if (!--header->count)
1899                 kfree(header);
1900         spin_unlock(&sysctl_lock);
1901 }
1902
1903 int sysctl_is_seen(struct ctl_table_header *p)
1904 {
1905         struct ctl_table_set *set = p->set;
1906         int res;
1907         spin_lock(&sysctl_lock);
1908         if (p->unregistering)
1909                 res = 0;
1910         else if (!set->is_seen)
1911                 res = 1;
1912         else
1913                 res = set->is_seen(set);
1914         spin_unlock(&sysctl_lock);
1915         return res;
1916 }
1917
1918 void setup_sysctl_set(struct ctl_table_set *p,
1919         struct ctl_table_set *parent,
1920         int (*is_seen)(struct ctl_table_set *))
1921 {
1922         INIT_LIST_HEAD(&p->list);
1923         p->parent = parent ? parent : &sysctl_table_root.default_set;
1924         p->is_seen = is_seen;
1925 }
1926
1927 #else /* !CONFIG_SYSCTL */
1928 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1929 {
1930         return NULL;
1931 }
1932
1933 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1934                                                     struct ctl_table *table)
1935 {
1936         return NULL;
1937 }
1938
1939 void unregister_sysctl_table(struct ctl_table_header * table)
1940 {
1941 }
1942
1943 void setup_sysctl_set(struct ctl_table_set *p,
1944         struct ctl_table_set *parent,
1945         int (*is_seen)(struct ctl_table_set *))
1946 {
1947 }
1948
1949 void sysctl_head_put(struct ctl_table_header *head)
1950 {
1951 }
1952
1953 #endif /* CONFIG_SYSCTL */
1954
1955 /*
1956  * /proc/sys support
1957  */
1958
1959 #ifdef CONFIG_PROC_SYSCTL
1960
1961 static int _proc_do_string(void* data, int maxlen, int write,
1962                            void __user *buffer,
1963                            size_t *lenp, loff_t *ppos)
1964 {
1965         size_t len;
1966         char __user *p;
1967         char c;
1968
1969         if (!data || !maxlen || !*lenp) {
1970                 *lenp = 0;
1971                 return 0;
1972         }
1973
1974         if (write) {
1975                 len = 0;
1976                 p = buffer;
1977                 while (len < *lenp) {
1978                         if (get_user(c, p++))
1979                                 return -EFAULT;
1980                         if (c == 0 || c == '\n')
1981                                 break;
1982                         len++;
1983                 }
1984                 if (len >= maxlen)
1985                         len = maxlen-1;
1986                 if(copy_from_user(data, buffer, len))
1987                         return -EFAULT;
1988                 ((char *) data)[len] = 0;
1989                 *ppos += *lenp;
1990         } else {
1991                 len = strlen(data);
1992                 if (len > maxlen)
1993                         len = maxlen;
1994
1995                 if (*ppos > len) {
1996                         *lenp = 0;
1997                         return 0;
1998                 }
1999
2000                 data += *ppos;
2001                 len  -= *ppos;
2002
2003                 if (len > *lenp)
2004                         len = *lenp;
2005                 if (len)
2006                         if(copy_to_user(buffer, data, len))
2007                                 return -EFAULT;
2008                 if (len < *lenp) {
2009                         if(put_user('\n', ((char __user *) buffer) + len))
2010                                 return -EFAULT;
2011                         len++;
2012                 }
2013                 *lenp = len;
2014                 *ppos += len;
2015         }
2016         return 0;
2017 }
2018
2019 /**
2020  * proc_dostring - read a string sysctl
2021  * @table: the sysctl table
2022  * @write: %TRUE if this is a write to the sysctl file
2023  * @buffer: the user buffer
2024  * @lenp: the size of the user buffer
2025  * @ppos: file position
2026  *
2027  * Reads/writes a string from/to the user buffer. If the kernel
2028  * buffer provided is not large enough to hold the string, the
2029  * string is truncated. The copied string is %NULL-terminated.
2030  * If the string is being read by the user process, it is copied
2031  * and a newline '\n' is added. It is truncated if the buffer is
2032  * not large enough.
2033  *
2034  * Returns 0 on success.
2035  */
2036 int proc_dostring(struct ctl_table *table, int write,
2037                   void __user *buffer, size_t *lenp, loff_t *ppos)
2038 {
2039         return _proc_do_string(table->data, table->maxlen, write,
2040                                buffer, lenp, ppos);
2041 }
2042
2043 static size_t proc_skip_spaces(char **buf)
2044 {
2045         size_t ret;
2046         char *tmp = skip_spaces(*buf);
2047         ret = tmp - *buf;
2048         *buf = tmp;
2049         return ret;
2050 }
2051
2052 static void proc_skip_char(char **buf, size_t *size, const char v)
2053 {
2054         while (*size) {
2055                 if (**buf != v)
2056                         break;
2057                 (*size)--;
2058                 (*buf)++;
2059         }
2060 }
2061
2062 #define TMPBUFLEN 22
2063 /**
2064  * proc_get_long - reads an ASCII formated integer from a user buffer
2065  *
2066  * @buf - a kernel buffer
2067  * @size - size of the kernel buffer
2068  * @val - this is where the number will be stored
2069  * @neg - set to %TRUE if number is negative
2070  * @perm_tr - a vector which contains the allowed trailers
2071  * @perm_tr_len - size of the perm_tr vector
2072  * @tr - pointer to store the trailer character
2073  *
2074  * In case of success 0 is returned and buf and size are updated with
2075  * the amount of bytes read. If tr is non NULL and a trailing
2076  * character exist (size is non zero after returning from this
2077  * function) tr is updated with the trailing character.
2078  */
2079 static int proc_get_long(char **buf, size_t *size,
2080                           unsigned long *val, bool *neg,
2081                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2082 {
2083         int len;
2084         char *p, tmp[TMPBUFLEN];
2085
2086         if (!*size)
2087                 return -EINVAL;
2088
2089         len = *size;
2090         if (len > TMPBUFLEN - 1)
2091                 len = TMPBUFLEN - 1;
2092
2093         memcpy(tmp, *buf, len);
2094
2095         tmp[len] = 0;
2096         p = tmp;
2097         if (*p == '-' && *size > 1) {
2098                 *neg = true;
2099                 p++;
2100         } else
2101                 *neg = false;
2102         if (!isdigit(*p))
2103                 return -EINVAL;
2104
2105         *val = simple_strtoul(p, &p, 0);
2106
2107         len = p - tmp;
2108
2109         /* We don't know if the next char is whitespace thus we may accept
2110          * invalid integers (e.g. 1234...a) or two integers instead of one
2111          * (e.g. 123...1). So lets not allow such large numbers. */
2112         if (len == TMPBUFLEN - 1)
2113                 return -EINVAL;
2114
2115         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2116                 return -EINVAL;
2117
2118         if (tr && (len < *size))
2119                 *tr = *p;
2120
2121         *buf += len;
2122         *size -= len;
2123
2124         return 0;
2125 }
2126
2127 /**
2128  * proc_put_long - coverts an integer to a decimal ASCII formated string
2129  *
2130  * @buf - the user buffer
2131  * @size - the size of the user buffer
2132  * @val - the integer to be converted
2133  * @neg - sign of the number, %TRUE for negative
2134  *
2135  * In case of success 0 is returned and buf and size are updated with
2136  * the amount of bytes read.
2137  */
2138 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2139                           bool neg)
2140 {
2141         int len;
2142         char tmp[TMPBUFLEN], *p = tmp;
2143
2144         sprintf(p, "%s%lu", neg ? "-" : "", val);
2145         len = strlen(tmp);
2146         if (len > *size)
2147                 len = *size;
2148         if (copy_to_user(*buf, tmp, len))
2149                 return -EFAULT;
2150         *size -= len;
2151         *buf += len;
2152         return 0;
2153 }
2154 #undef TMPBUFLEN
2155
2156 static int proc_put_char(void __user **buf, size_t *size, char c)
2157 {
2158         if (*size) {
2159                 char __user **buffer = (char __user **)buf;
2160                 if (put_user(c, *buffer))
2161                         return -EFAULT;
2162                 (*size)--, (*buffer)++;
2163                 *buf = *buffer;
2164         }
2165         return 0;
2166 }
2167
2168 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2169                                  int *valp,
2170                                  int write, void *data)
2171 {
2172         if (write) {
2173                 *valp = *negp ? -*lvalp : *lvalp;
2174         } else {
2175                 int val = *valp;
2176                 if (val < 0) {
2177                         *negp = true;
2178                         *lvalp = (unsigned long)-val;
2179                 } else {
2180                         *negp = false;
2181                         *lvalp = (unsigned long)val;
2182                 }
2183         }
2184         return 0;
2185 }
2186
2187 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2188
2189 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2190                   int write, void __user *buffer,
2191                   size_t *lenp, loff_t *ppos,
2192                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2193                               int write, void *data),
2194                   void *data)
2195 {
2196         int *i, vleft, first = 1, err = 0;
2197         unsigned long page = 0;
2198         size_t left;
2199         char *kbuf;
2200
2201         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2202                 *lenp = 0;
2203                 return 0;
2204         }
2205
2206         i = (int *) tbl_data;
2207         vleft = table->maxlen / sizeof(*i);
2208         left = *lenp;
2209
2210         if (!conv)
2211                 conv = do_proc_dointvec_conv;
2212
2213         if (write) {
2214                 if (left > PAGE_SIZE - 1)
2215                         left = PAGE_SIZE - 1;
2216                 page = __get_free_page(GFP_TEMPORARY);
2217                 kbuf = (char *) page;
2218                 if (!kbuf)
2219                         return -ENOMEM;
2220                 if (copy_from_user(kbuf, buffer, left)) {
2221                         err = -EFAULT;
2222                         goto free;
2223                 }
2224                 kbuf[left] = 0;
2225         }
2226
2227         for (; left && vleft--; i++, first=0) {
2228                 unsigned long lval;
2229                 bool neg;
2230
2231                 if (write) {
2232                         left -= proc_skip_spaces(&kbuf);
2233
2234                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2235                                              proc_wspace_sep,
2236                                              sizeof(proc_wspace_sep), NULL);
2237                         if (err)
2238                                 break;
2239                         if (conv(&neg, &lval, i, 1, data)) {
2240                                 err = -EINVAL;
2241                                 break;
2242                         }
2243                 } else {
2244                         if (conv(&neg, &lval, i, 0, data)) {
2245                                 err = -EINVAL;
2246                                 break;
2247                         }
2248                         if (!first)
2249                                 err = proc_put_char(&buffer, &left, '\t');
2250                         if (err)
2251                                 break;
2252                         err = proc_put_long(&buffer, &left, lval, neg);
2253                         if (err)
2254                                 break;
2255                 }
2256         }
2257
2258         if (!write && !first && left && !err)
2259                 err = proc_put_char(&buffer, &left, '\n');
2260         if (write && !err)
2261                 left -= proc_skip_spaces(&kbuf);
2262 free:
2263         if (write) {
2264                 free_page(page);
2265                 if (first)
2266                         return err ? : -EINVAL;
2267         }
2268         *lenp -= left;
2269         *ppos += *lenp;
2270         return err;
2271 }
2272
2273 static int do_proc_dointvec(struct ctl_table *table, int write,
2274                   void __user *buffer, size_t *lenp, loff_t *ppos,
2275                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2276                               int write, void *data),
2277                   void *data)
2278 {
2279         return __do_proc_dointvec(table->data, table, write,
2280                         buffer, lenp, ppos, conv, data);
2281 }
2282
2283 /**
2284  * proc_dointvec - read a vector of integers
2285  * @table: the sysctl table
2286  * @write: %TRUE if this is a write to the sysctl file
2287  * @buffer: the user buffer
2288  * @lenp: the size of the user buffer
2289  * @ppos: file position
2290  *
2291  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2292  * values from/to the user buffer, treated as an ASCII string.
2293  *
2294  * Returns 0 on success.
2295  */
2296 int proc_dointvec(struct ctl_table *table, int write,
2297                      void __user *buffer, size_t *lenp, loff_t *ppos)
2298 {
2299     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2300                             NULL,NULL);
2301 }
2302
2303 /*
2304  * Taint values can only be increased
2305  * This means we can safely use a temporary.
2306  */
2307 static int proc_taint(struct ctl_table *table, int write,
2308                                void __user *buffer, size_t *lenp, loff_t *ppos)
2309 {
2310         struct ctl_table t;
2311         unsigned long tmptaint = get_taint();
2312         int err;
2313
2314         if (write && !capable(CAP_SYS_ADMIN))
2315                 return -EPERM;
2316
2317         t = *table;
2318         t.data = &tmptaint;
2319         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2320         if (err < 0)
2321                 return err;
2322
2323         if (write) {
2324                 /*
2325                  * Poor man's atomic or. Not worth adding a primitive
2326                  * to everyone's atomic.h for this
2327                  */
2328                 int i;
2329                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2330                         if ((tmptaint >> i) & 1)
2331                                 add_taint(i);
2332                 }
2333         }
2334
2335         return err;
2336 }
2337
2338 struct do_proc_dointvec_minmax_conv_param {
2339         int *min;
2340         int *max;
2341 };
2342
2343 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2344                                         int *valp,
2345                                         int write, void *data)
2346 {
2347         struct do_proc_dointvec_minmax_conv_param *param = data;
2348         if (write) {
2349                 int val = *negp ? -*lvalp : *lvalp;
2350                 if ((param->min && *param->min > val) ||
2351                     (param->max && *param->max < val))
2352                         return -EINVAL;
2353                 *valp = val;
2354         } else {
2355                 int val = *valp;
2356                 if (val < 0) {
2357                         *negp = true;
2358                         *lvalp = (unsigned long)-val;
2359                 } else {
2360                         *negp = false;
2361                         *lvalp = (unsigned long)val;
2362                 }
2363         }
2364         return 0;
2365 }
2366
2367 /**
2368  * proc_dointvec_minmax - read a vector of integers with min/max values
2369  * @table: the sysctl table
2370  * @write: %TRUE if this is a write to the sysctl file
2371  * @buffer: the user buffer
2372  * @lenp: the size of the user buffer
2373  * @ppos: file position
2374  *
2375  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2376  * values from/to the user buffer, treated as an ASCII string.
2377  *
2378  * This routine will ensure the values are within the range specified by
2379  * table->extra1 (min) and table->extra2 (max).
2380  *
2381  * Returns 0 on success.
2382  */
2383 int proc_dointvec_minmax(struct ctl_table *table, int write,
2384                   void __user *buffer, size_t *lenp, loff_t *ppos)
2385 {
2386         struct do_proc_dointvec_minmax_conv_param param = {
2387                 .min = (int *) table->extra1,
2388                 .max = (int *) table->extra2,
2389         };
2390         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2391                                 do_proc_dointvec_minmax_conv, &param);
2392 }
2393
2394 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2395                                      void __user *buffer,
2396                                      size_t *lenp, loff_t *ppos,
2397                                      unsigned long convmul,
2398                                      unsigned long convdiv)
2399 {
2400         unsigned long *i, *min, *max;
2401         int vleft, first = 1, err = 0;
2402         unsigned long page = 0;
2403         size_t left;
2404         char *kbuf;
2405
2406         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2407                 *lenp = 0;
2408                 return 0;
2409         }
2410
2411         i = (unsigned long *) data;
2412         min = (unsigned long *) table->extra1;
2413         max = (unsigned long *) table->extra2;
2414         vleft = table->maxlen / sizeof(unsigned long);
2415         left = *lenp;
2416
2417         if (write) {
2418                 if (left > PAGE_SIZE - 1)
2419                         left = PAGE_SIZE - 1;
2420                 page = __get_free_page(GFP_TEMPORARY);
2421                 kbuf = (char *) page;
2422                 if (!kbuf)
2423                         return -ENOMEM;
2424                 if (copy_from_user(kbuf, buffer, left)) {
2425                         err = -EFAULT;
2426                         goto free;
2427                 }
2428                 kbuf[left] = 0;
2429         }
2430
2431         for (; left && vleft--; i++, min++, max++, first=0) {
2432                 unsigned long val;
2433
2434                 if (write) {
2435                         bool neg;
2436
2437                         left -= proc_skip_spaces(&kbuf);
2438
2439                         err = proc_get_long(&kbuf, &left, &val, &neg,
2440                                              proc_wspace_sep,
2441                                              sizeof(proc_wspace_sep), NULL);
2442                         if (err)
2443                                 break;
2444                         if (neg)
2445                                 continue;
2446                         if ((min && val < *min) || (max && val > *max))
2447                                 continue;
2448                         *i = val;
2449                 } else {
2450                         val = convdiv * (*i) / convmul;
2451                         if (!first)
2452                                 err = proc_put_char(&buffer, &left, '\t');
2453                         err = proc_put_long(&buffer, &left, val, false);
2454                         if (err)
2455                                 break;
2456                 }
2457         }
2458
2459         if (!write && !first && left && !err)
2460                 err = proc_put_char(&buffer, &left, '\n');
2461         if (write && !err)
2462                 left -= proc_skip_spaces(&kbuf);
2463 free:
2464         if (write) {
2465                 free_page(page);
2466                 if (first)
2467                         return err ? : -EINVAL;
2468         }
2469         *lenp -= left;
2470         *ppos += *lenp;
2471         return err;
2472 }
2473
2474 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2475                                      void __user *buffer,
2476                                      size_t *lenp, loff_t *ppos,
2477                                      unsigned long convmul,
2478                                      unsigned long convdiv)
2479 {
2480         return __do_proc_doulongvec_minmax(table->data, table, write,
2481                         buffer, lenp, ppos, convmul, convdiv);
2482 }
2483
2484 /**
2485  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2486  * @table: the sysctl table
2487  * @write: %TRUE if this is a write to the sysctl file
2488  * @buffer: the user buffer
2489  * @lenp: the size of the user buffer
2490  * @ppos: file position
2491  *
2492  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2493  * values from/to the user buffer, treated as an ASCII string.
2494  *
2495  * This routine will ensure the values are within the range specified by
2496  * table->extra1 (min) and table->extra2 (max).
2497  *
2498  * Returns 0 on success.
2499  */
2500 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2501                            void __user *buffer, size_t *lenp, loff_t *ppos)
2502 {
2503     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2504 }
2505
2506 /**
2507  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2508  * @table: the sysctl table
2509  * @write: %TRUE if this is a write to the sysctl file
2510  * @buffer: the user buffer
2511  * @lenp: the size of the user buffer
2512  * @ppos: file position
2513  *
2514  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2515  * values from/to the user buffer, treated as an ASCII string. The values
2516  * are treated as milliseconds, and converted to jiffies when they are stored.
2517  *
2518  * This routine will ensure the values are within the range specified by
2519  * table->extra1 (min) and table->extra2 (max).
2520  *
2521  * Returns 0 on success.
2522  */
2523 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2524                                       void __user *buffer,
2525                                       size_t *lenp, loff_t *ppos)
2526 {
2527     return do_proc_doulongvec_minmax(table, write, buffer,
2528                                      lenp, ppos, HZ, 1000l);
2529 }
2530
2531
2532 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2533                                          int *valp,
2534                                          int write, void *data)
2535 {
2536         if (write) {
2537                 if (*lvalp > LONG_MAX / HZ)
2538                         return 1;
2539                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2540         } else {
2541                 int val = *valp;
2542                 unsigned long lval;
2543                 if (val < 0) {
2544                         *negp = true;
2545                         lval = (unsigned long)-val;
2546                 } else {
2547                         *negp = false;
2548                         lval = (unsigned long)val;
2549                 }
2550                 *lvalp = lval / HZ;
2551         }
2552         return 0;
2553 }
2554
2555 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2556                                                 int *valp,
2557                                                 int write, void *data)
2558 {
2559         if (write) {
2560                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2561                         return 1;
2562                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2563         } else {
2564                 int val = *valp;
2565                 unsigned long lval;
2566                 if (val < 0) {
2567                         *negp = true;
2568                         lval = (unsigned long)-val;
2569                 } else {
2570                         *negp = false;
2571                         lval = (unsigned long)val;
2572                 }
2573                 *lvalp = jiffies_to_clock_t(lval);
2574         }
2575         return 0;
2576 }
2577
2578 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2579                                             int *valp,
2580                                             int write, void *data)
2581 {
2582         if (write) {
2583                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2584         } else {
2585                 int val = *valp;
2586                 unsigned long lval;
2587                 if (val < 0) {
2588                         *negp = true;
2589                         lval = (unsigned long)-val;
2590                 } else {
2591                         *negp = false;
2592                         lval = (unsigned long)val;
2593                 }
2594                 *lvalp = jiffies_to_msecs(lval);
2595         }
2596         return 0;
2597 }
2598
2599 /**
2600  * proc_dointvec_jiffies - read a vector of integers as seconds
2601  * @table: the sysctl table
2602  * @write: %TRUE if this is a write to the sysctl file
2603  * @buffer: the user buffer
2604  * @lenp: the size of the user buffer
2605  * @ppos: file position
2606  *
2607  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2608  * values from/to the user buffer, treated as an ASCII string.
2609  * The values read are assumed to be in seconds, and are converted into
2610  * jiffies.
2611  *
2612  * Returns 0 on success.
2613  */
2614 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2615                           void __user *buffer, size_t *lenp, loff_t *ppos)
2616 {
2617     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2618                             do_proc_dointvec_jiffies_conv,NULL);
2619 }
2620
2621 /**
2622  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2623  * @table: the sysctl table
2624  * @write: %TRUE if this is a write to the sysctl file
2625  * @buffer: the user buffer
2626  * @lenp: the size of the user buffer
2627  * @ppos: pointer to the file position
2628  *
2629  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2630  * values from/to the user buffer, treated as an ASCII string.
2631  * The values read are assumed to be in 1/USER_HZ seconds, and
2632  * are converted into jiffies.
2633  *
2634  * Returns 0 on success.
2635  */
2636 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2637                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2638 {
2639     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2640                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2641 }
2642
2643 /**
2644  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2645  * @table: the sysctl table
2646  * @write: %TRUE if this is a write to the sysctl file
2647  * @buffer: the user buffer
2648  * @lenp: the size of the user buffer
2649  * @ppos: file position
2650  * @ppos: the current position in the file
2651  *
2652  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2653  * values from/to the user buffer, treated as an ASCII string.
2654  * The values read are assumed to be in 1/1000 seconds, and
2655  * are converted into jiffies.
2656  *
2657  * Returns 0 on success.
2658  */
2659 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2660                              void __user *buffer, size_t *lenp, loff_t *ppos)
2661 {
2662         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2663                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2664 }
2665
2666 static int proc_do_cad_pid(struct ctl_table *table, int write,
2667                            void __user *buffer, size_t *lenp, loff_t *ppos)
2668 {
2669         struct pid *new_pid;
2670         pid_t tmp;
2671         int r;
2672
2673         tmp = pid_vnr(cad_pid);
2674
2675         r = __do_proc_dointvec(&tmp, table, write, buffer,
2676                                lenp, ppos, NULL, NULL);
2677         if (r || !write)
2678                 return r;
2679
2680         new_pid = find_get_pid(tmp);
2681         if (!new_pid)
2682                 return -ESRCH;
2683
2684         put_pid(xchg(&cad_pid, new_pid));
2685         return 0;
2686 }
2687
2688 /**
2689  * proc_do_large_bitmap - read/write from/to a large bitmap
2690  * @table: the sysctl table
2691  * @write: %TRUE if this is a write to the sysctl file
2692  * @buffer: the user buffer
2693  * @lenp: the size of the user buffer
2694  * @ppos: file position
2695  *
2696  * The bitmap is stored at table->data and the bitmap length (in bits)
2697  * in table->maxlen.
2698  *
2699  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2700  * large bitmaps may be represented in a compact manner. Writing into
2701  * the file will clear the bitmap then update it with the given input.
2702  *
2703  * Returns 0 on success.
2704  */
2705 int proc_do_large_bitmap(struct ctl_table *table, int write,
2706                          void __user *buffer, size_t *lenp, loff_t *ppos)
2707 {
2708         int err = 0;
2709         bool first = 1;
2710         size_t left = *lenp;
2711         unsigned long bitmap_len = table->maxlen;
2712         unsigned long *bitmap = (unsigned long *) table->data;
2713         unsigned long *tmp_bitmap = NULL;
2714         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2715
2716         if (!bitmap_len || !left || (*ppos && !write)) {
2717                 *lenp = 0;
2718                 return 0;
2719         }
2720
2721         if (write) {
2722                 unsigned long page = 0;
2723                 char *kbuf;
2724
2725                 if (left > PAGE_SIZE - 1)
2726                         left = PAGE_SIZE - 1;
2727
2728                 page = __get_free_page(GFP_TEMPORARY);
2729                 kbuf = (char *) page;
2730                 if (!kbuf)
2731                         return -ENOMEM;
2732                 if (copy_from_user(kbuf, buffer, left)) {
2733                         free_page(page);
2734                         return -EFAULT;
2735                 }
2736                 kbuf[left] = 0;
2737
2738                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2739                                      GFP_KERNEL);
2740                 if (!tmp_bitmap) {
2741                         free_page(page);
2742                         return -ENOMEM;
2743                 }
2744                 proc_skip_char(&kbuf, &left, '\n');
2745                 while (!err && left) {
2746                         unsigned long val_a, val_b;
2747                         bool neg;
2748
2749                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2750                                              sizeof(tr_a), &c);
2751                         if (err)
2752                                 break;
2753                         if (val_a >= bitmap_len || neg) {
2754                                 err = -EINVAL;
2755                                 break;
2756                         }
2757
2758                         val_b = val_a;
2759                         if (left) {
2760                                 kbuf++;
2761                                 left--;
2762                         }
2763
2764                         if (c == '-') {
2765                                 err = proc_get_long(&kbuf, &left, &val_b,
2766                                                      &neg, tr_b, sizeof(tr_b),
2767                                                      &c);
2768                                 if (err)
2769                                         break;
2770                                 if (val_b >= bitmap_len || neg ||
2771                                     val_a > val_b) {
2772                                         err = -EINVAL;
2773                                         break;
2774                                 }
2775                                 if (left) {
2776                                         kbuf++;
2777                                         left--;
2778                                 }
2779                         }
2780
2781                         while (val_a <= val_b)
2782                                 set_bit(val_a++, tmp_bitmap);
2783
2784                         first = 0;
2785                         proc_skip_char(&kbuf, &left, '\n');
2786                 }
2787                 free_page(page);
2788         } else {
2789                 unsigned long bit_a, bit_b = 0;
2790
2791                 while (left) {
2792                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2793                         if (bit_a >= bitmap_len)
2794                                 break;
2795                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2796                                                    bit_a + 1) - 1;
2797
2798                         if (!first) {
2799                                 err = proc_put_char(&buffer, &left, ',');
2800                                 if (err)
2801                                         break;
2802                         }
2803                         err = proc_put_long(&buffer, &left, bit_a, false);
2804                         if (err)
2805                                 break;
2806                         if (bit_a != bit_b) {
2807                                 err = proc_put_char(&buffer, &left, '-');
2808                                 if (err)
2809                                         break;
2810                                 err = proc_put_long(&buffer, &left, bit_b, false);
2811                                 if (err)
2812                                         break;
2813                         }
2814
2815                         first = 0; bit_b++;
2816                 }
2817                 if (!err)
2818                         err = proc_put_char(&buffer, &left, '\n');
2819         }
2820
2821         if (!err) {
2822                 if (write) {
2823                         if (*ppos)
2824                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2825                         else
2826                                 memcpy(bitmap, tmp_bitmap,
2827                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2828                 }
2829                 kfree(tmp_bitmap);
2830                 *lenp -= left;
2831                 *ppos += *lenp;
2832                 return 0;
2833         } else {
2834                 kfree(tmp_bitmap);
2835                 return err;
2836         }
2837 }
2838
2839 #else /* CONFIG_PROC_FS */
2840
2841 int proc_dostring(struct ctl_table *table, int write,
2842                   void __user *buffer, size_t *lenp, loff_t *ppos)
2843 {
2844         return -ENOSYS;
2845 }
2846
2847 int proc_dointvec(struct ctl_table *table, int write,
2848                   void __user *buffer, size_t *lenp, loff_t *ppos)
2849 {
2850         return -ENOSYS;
2851 }
2852
2853 int proc_dointvec_minmax(struct ctl_table *table, int write,
2854                     void __user *buffer, size_t *lenp, loff_t *ppos)
2855 {
2856         return -ENOSYS;
2857 }
2858
2859 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2860                     void __user *buffer, size_t *lenp, loff_t *ppos)
2861 {
2862         return -ENOSYS;
2863 }
2864
2865 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2866                     void __user *buffer, size_t *lenp, loff_t *ppos)
2867 {
2868         return -ENOSYS;
2869 }
2870
2871 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2872                              void __user *buffer, size_t *lenp, loff_t *ppos)
2873 {
2874         return -ENOSYS;
2875 }
2876
2877 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2878                     void __user *buffer, size_t *lenp, loff_t *ppos)
2879 {
2880         return -ENOSYS;
2881 }
2882
2883 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2884                                       void __user *buffer,
2885                                       size_t *lenp, loff_t *ppos)
2886 {
2887     return -ENOSYS;
2888 }
2889
2890
2891 #endif /* CONFIG_PROC_FS */
2892
2893 /*
2894  * No sense putting this after each symbol definition, twice,
2895  * exception granted :-)
2896  */
2897 EXPORT_SYMBOL(proc_dointvec);
2898 EXPORT_SYMBOL(proc_dointvec_jiffies);
2899 EXPORT_SYMBOL(proc_dointvec_minmax);
2900 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2901 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2902 EXPORT_SYMBOL(proc_dostring);
2903 EXPORT_SYMBOL(proc_doulongvec_minmax);
2904 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2905 EXPORT_SYMBOL(register_sysctl_table);
2906 EXPORT_SYMBOL(register_sysctl_paths);
2907 EXPORT_SYMBOL(unregister_sysctl_table);