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