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