kernel/sysctl.c

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