kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/signal.h>
  27 #include <linux/printk.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/security.h>
  30 #include <linux/ctype.h>
  31 #include <linux/kmemcheck.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/ratelimit.h>
  41 #include <linux/compaction.h>
  42 #include <linux/hugetlb.h>
  43 #include <linux/initrd.h>
  44 #include <linux/key.h>
  45 #include <linux/times.h>
  46 #include <linux/limits.h>
  47 #include <linux/dcache.h>
  48 #include <linux/dnotify.h>
  49 #include <linux/syscalls.h>
  50 #include <linux/vmstat.h>
  51 #include <linux/nfs_fs.h>
  52 #include <linux/acpi.h>
  53 #include <linux/reboot.h>
  54 #include <linux/ftrace.h>
  55 #include <linux/perf_event.h>
  56 #include <linux/kprobes.h>
  57 #include <linux/pipe_fs_i.h>
  58 #include <linux/oom.h>
  59 #include <linux/kmod.h>
  60
  61 #include <asm/uaccess.h>
  62 #include <asm/processor.h>
  63
  64 #ifdef CONFIG_X86
  65 #include <asm/nmi.h>
  66 #include <asm/stacktrace.h>
  67 #include <asm/io.h>
  68 #endif
  69 #ifdef CONFIG_BSD_PROCESS_ACCT
  70 #include <linux/acct.h>
  71 #endif
  72 #ifdef CONFIG_RT_MUTEXES
  73 #include <linux/rtmutex.h>
  74 #endif
  75 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  76 #include <linux/lockdep.h>
  77 #endif
  78 #ifdef CONFIG_CHR_DEV_SG
  79 #include <scsi/sg.h>
  80 #endif
  81
  82 #ifdef CONFIG_LOCKUP_DETECTOR
  83 #include <linux/nmi.h>
  84 #endif
  85
  86
  87 #if defined(CONFIG_SYSCTL)
  88
  89 /* External variables not in a header file. */
  90 extern int sysctl_overcommit_memory;
  91 extern int sysctl_overcommit_ratio;
  92 extern int max_threads;
  93 extern int core_uses_pid;
  94 extern int suid_dumpable;
  95 extern char core_pattern[];
  96 extern unsigned int core_pipe_limit;
  97 extern int pid_max;
  98 extern int min_free_kbytes;
  99 extern int pid_max_min, pid_max_max;
 100 extern int sysctl_drop_caches;
 101 extern int percpu_pagelist_fraction;
 102 extern int compat_log;
 103 extern int latencytop_enabled;
 104 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 105 #ifndef CONFIG_MMU
 106 extern int sysctl_nr_trim_pages;
 107 #endif
 108 #ifdef CONFIG_BLOCK
 109 extern int blk_iopoll_enabled;
 110 #endif
 111
 112 /* Constants used for minimum and  maximum */
 113 #ifdef CONFIG_LOCKUP_DETECTOR
 114 static int sixty = 60;
 115 static int neg_one = -1;
 116 #endif
 117
 118 static int zero;
 119 static int __maybe_unused one = 1;
 120 static int __maybe_unused two = 2;
 121 static int __maybe_unused three = 3;
 122 static unsigned long one_ul = 1;
 123 static int one_hundred = 100;
 124 #ifdef CONFIG_PRINTK
 125 static int ten_thousand = 10000;
 126 #endif
 127
 128 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 129 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 130
 131 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 132 static int maxolduid = 65535;
 133 static int minolduid;
 134 static int min_percpu_pagelist_fract = 8;
 135
 136 static int ngroups_max = NGROUPS_MAX;
 137
 138 #ifdef CONFIG_INOTIFY_USER
 139 #include <linux/inotify.h>
 140 #endif
 141 #ifdef CONFIG_SPARC
 142 #include <asm/system.h>
 143 #endif
 144
 145 #ifdef CONFIG_SPARC64
 146 extern int sysctl_tsb_ratio;
 147 #endif
 148
 149 #ifdef __hppa__
 150 extern int pwrsw_enabled;
 151 extern int unaligned_enabled;
 152 #endif
 153
 154 #ifdef CONFIG_S390
 155 #ifdef CONFIG_MATHEMU
 156 extern int sysctl_ieee_emulation_warnings;
 157 #endif
 158 extern int sysctl_userprocess_debug;
 159 extern int spin_retry;
 160 #endif
 161
 162 #ifdef CONFIG_IA64
 163 extern int no_unaligned_warning;
 164 extern int unaligned_dump_stack;
 165 #endif
 166
 167 #ifdef CONFIG_PROC_SYSCTL
 168 static int proc_do_cad_pid(struct ctl_table *table, int write,
 169                   void __user *buffer, size_t *lenp, loff_t *ppos);
 170 static int proc_taint(struct ctl_table *table, int write,
 171                                void __user *buffer, size_t *lenp, loff_t *ppos);
 172 #endif
 173
 174 #ifdef CONFIG_PRINTK
 175 static int proc_dmesg_restrict(struct ctl_table *table, int write,
 176                                 void __user *buffer, size_t *lenp, loff_t *ppos);
 177 #endif
 178
 179 #ifdef CONFIG_MAGIC_SYSRQ
 180 /* Note: sysrq code uses it's own private copy */
 181 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
 182
 183 static int sysrq_sysctl_handler(ctl_table *table, int write,
 184                                 void __user *buffer, size_t *lenp,
 185                                 loff_t *ppos)
 186 {
 187         int error;
 188
 189         error = proc_dointvec(table, write, buffer, lenp, ppos);
 190         if (error)
 191                 return error;
 192
 193         if (write)
 194                 sysrq_toggle_support(__sysrq_enabled);
 195
 196         return 0;
 197 }
 198
 199 #endif
 200
 201 static struct ctl_table root_table[];
 202 static struct ctl_table_root sysctl_table_root;
 203 static struct ctl_table_header root_table_header = {
 204         {{.count = 1,
 205         .ctl_table = root_table,
 206         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
 207         .root = &sysctl_table_root,
 208         .set = &sysctl_table_root.default_set,
 209 };
 210 static struct ctl_table_root sysctl_table_root = {
 211         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 212         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 213 };
 214
 215 static struct ctl_table kern_table[];
 216 static struct ctl_table vm_table[];
 217 static struct ctl_table fs_table[];
 218 static struct ctl_table debug_table[];
 219 static struct ctl_table dev_table[];
 220 extern struct ctl_table random_table[];
 221 #ifdef CONFIG_EPOLL
 222 extern struct ctl_table epoll_table[];
 223 #endif
 224
 225 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 226 int sysctl_legacy_va_layout;
 227 #endif
 228
 229 /* The default sysctl tables: */
 230
 231 static struct ctl_table root_table[] = {
 232         {
 233                 .procname       = "kernel",
 234                 .mode           = 0555,
 235                 .child          = kern_table,
 236         },
 237         {
 238                 .procname       = "vm",
 239                 .mode           = 0555,
 240                 .child          = vm_table,
 241         },
 242         {
 243                 .procname       = "fs",
 244                 .mode           = 0555,
 245                 .child          = fs_table,
 246         },
 247         {
 248                 .procname       = "debug",
 249                 .mode           = 0555,
 250                 .child          = debug_table,
 251         },
 252         {
 253                 .procname       = "dev",
 254                 .mode           = 0555,
 255                 .child          = dev_table,
 256         },
 257         { }
 258 };
 259
 260 #ifdef CONFIG_SCHED_DEBUG
 261 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 262 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 263 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 264 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 265 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 266 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 267 #endif
 268
 269 #ifdef CONFIG_COMPACTION
 270 static int min_extfrag_threshold;
 271 static int max_extfrag_threshold = 1000;
 272 #endif
 273
 274 static struct ctl_table kern_table[] = {
 275         {
 276                 .procname       = "sched_child_runs_first",
 277                 .data           = &sysctl_sched_child_runs_first,
 278                 .maxlen         = sizeof(unsigned int),
 279                 .mode           = 0644,
 280                 .proc_handler   = proc_dointvec,
 281         },
 282 #ifdef CONFIG_SCHED_DEBUG
 283         {
 284                 .procname       = "sched_min_granularity_ns",
 285                 .data           = &sysctl_sched_min_granularity,
 286                 .maxlen         = sizeof(unsigned int),
 287                 .mode           = 0644,
 288                 .proc_handler   = sched_proc_update_handler,
 289                 .extra1         = &min_sched_granularity_ns,
 290                 .extra2         = &max_sched_granularity_ns,
 291         },
 292         {
 293                 .procname       = "sched_latency_ns",
 294                 .data           = &sysctl_sched_latency,
 295                 .maxlen         = sizeof(unsigned int),
 296                 .mode           = 0644,
 297                 .proc_handler   = sched_proc_update_handler,
 298                 .extra1         = &min_sched_granularity_ns,
 299                 .extra2         = &max_sched_granularity_ns,
 300         },
 301         {
 302                 .procname       = "sched_wakeup_granularity_ns",
 303                 .data           = &sysctl_sched_wakeup_granularity,
 304                 .maxlen         = sizeof(unsigned int),
 305                 .mode           = 0644,
 306                 .proc_handler   = sched_proc_update_handler,
 307                 .extra1         = &min_wakeup_granularity_ns,
 308                 .extra2         = &max_wakeup_granularity_ns,
 309         },
 310         {
 311                 .procname       = "sched_tunable_scaling",
 312                 .data           = &sysctl_sched_tunable_scaling,
 313                 .maxlen         = sizeof(enum sched_tunable_scaling),
 314                 .mode           = 0644,
 315                 .proc_handler   = sched_proc_update_handler,
 316                 .extra1         = &min_sched_tunable_scaling,
 317                 .extra2         = &max_sched_tunable_scaling,
 318         },
 319         {
 320                 .procname       = "sched_migration_cost",
 321                 .data           = &sysctl_sched_migration_cost,
 322                 .maxlen         = sizeof(unsigned int),
 323                 .mode           = 0644,
 324                 .proc_handler   = proc_dointvec,
 325         },
 326         {
 327                 .procname       = "sched_nr_migrate",
 328                 .data           = &sysctl_sched_nr_migrate,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = proc_dointvec,
 332         },
 333         {
 334                 .procname       = "sched_time_avg",
 335                 .data           = &sysctl_sched_time_avg,
 336                 .maxlen         = sizeof(unsigned int),
 337                 .mode           = 0644,
 338                 .proc_handler   = proc_dointvec,
 339         },
 340         {
 341                 .procname       = "sched_shares_window",
 342                 .data           = &sysctl_sched_shares_window,
 343                 .maxlen         = sizeof(unsigned int),
 344                 .mode           = 0644,
 345                 .proc_handler   = proc_dointvec,
 346         },
 347         {
 348                 .procname       = "timer_migration",
 349                 .data           = &sysctl_timer_migration,
 350                 .maxlen         = sizeof(unsigned int),
 351                 .mode           = 0644,
 352                 .proc_handler   = proc_dointvec_minmax,
 353                 .extra1         = &zero,
 354                 .extra2         = &one,
 355         },
 356 #endif
 357         {
 358                 .procname       = "sched_rt_period_us",
 359                 .data           = &sysctl_sched_rt_period,
 360                 .maxlen         = sizeof(unsigned int),
 361                 .mode           = 0644,
 362                 .proc_handler   = sched_rt_handler,
 363         },
 364         {
 365                 .procname       = "sched_rt_runtime_us",
 366                 .data           = &sysctl_sched_rt_runtime,
 367                 .maxlen         = sizeof(int),
 368                 .mode           = 0644,
 369                 .proc_handler   = sched_rt_handler,
 370         },
 371 #ifdef CONFIG_SCHED_AUTOGROUP
 372         {
 373                 .procname       = "sched_autogroup_enabled",
 374                 .data           = &sysctl_sched_autogroup_enabled,
 375                 .maxlen         = sizeof(unsigned int),
 376                 .mode           = 0644,
 377                 .proc_handler   = proc_dointvec_minmax,
 378                 .extra1         = &zero,
 379                 .extra2         = &one,
 380         },
 381 #endif
 382 #ifdef CONFIG_CFS_BANDWIDTH
 383         {
 384                 .procname       = "sched_cfs_bandwidth_slice_us",
 385                 .data           = &sysctl_sched_cfs_bandwidth_slice,
 386                 .maxlen         = sizeof(unsigned int),
 387                 .mode           = 0644,
 388                 .proc_handler   = proc_dointvec_minmax,
 389                 .extra1         = &one,
 390         },
 391 #endif
 392 #ifdef CONFIG_PROVE_LOCKING
 393         {
 394                 .procname       = "prove_locking",
 395                 .data           = &prove_locking,
 396                 .maxlen         = sizeof(int),
 397                 .mode           = 0644,
 398                 .proc_handler   = proc_dointvec,
 399         },
 400 #endif
 401 #ifdef CONFIG_LOCK_STAT
 402         {
 403                 .procname       = "lock_stat",
 404                 .data           = &lock_stat,
 405                 .maxlen         = sizeof(int),
 406                 .mode           = 0644,
 407                 .proc_handler   = proc_dointvec,
 408         },
 409 #endif
 410         {
 411                 .procname       = "panic",
 412                 .data           = &panic_timeout,
 413                 .maxlen         = sizeof(int),
 414                 .mode           = 0644,
 415                 .proc_handler   = proc_dointvec,
 416         },
 417         {
 418                 .procname       = "core_uses_pid",
 419                 .data           = &core_uses_pid,
 420                 .maxlen         = sizeof(int),
 421                 .mode           = 0644,
 422                 .proc_handler   = proc_dointvec,
 423         },
 424         {
 425                 .procname       = "core_pattern",
 426                 .data           = core_pattern,
 427                 .maxlen         = CORENAME_MAX_SIZE,
 428                 .mode           = 0644,
 429                 .proc_handler   = proc_dostring,
 430         },
 431         {
 432                 .procname       = "core_pipe_limit",
 433                 .data           = &core_pipe_limit,
 434                 .maxlen         = sizeof(unsigned int),
 435                 .mode           = 0644,
 436                 .proc_handler   = proc_dointvec,
 437         },
 438 #ifdef CONFIG_PROC_SYSCTL
 439         {
 440                 .procname       = "tainted",
 441                 .maxlen         = sizeof(long),
 442                 .mode           = 0644,
 443                 .proc_handler   = proc_taint,
 444         },
 445 #endif
 446 #ifdef CONFIG_LATENCYTOP
 447         {
 448                 .procname       = "latencytop",
 449                 .data           = &latencytop_enabled,
 450                 .maxlen         = sizeof(int),
 451                 .mode           = 0644,
 452                 .proc_handler   = proc_dointvec,
 453         },
 454 #endif
 455 #ifdef CONFIG_BLK_DEV_INITRD
 456         {
 457                 .procname       = "real-root-dev",
 458                 .data           = &real_root_dev,
 459                 .maxlen         = sizeof(int),
 460                 .mode           = 0644,
 461                 .proc_handler   = proc_dointvec,
 462         },
 463 #endif
 464         {
 465                 .procname       = "print-fatal-signals",
 466                 .data           = &print_fatal_signals,
 467                 .maxlen         = sizeof(int),
 468                 .mode           = 0644,
 469                 .proc_handler   = proc_dointvec,
 470         },
 471 #ifdef CONFIG_SPARC
 472         {
 473                 .procname       = "reboot-cmd",
 474                 .data           = reboot_command,
 475                 .maxlen         = 256,
 476                 .mode           = 0644,
 477                 .proc_handler   = proc_dostring,
 478         },
 479         {
 480                 .procname       = "stop-a",
 481                 .data           = &stop_a_enabled,
 482                 .maxlen         = sizeof (int),
 483                 .mode           = 0644,
 484                 .proc_handler   = proc_dointvec,
 485         },
 486         {
 487                 .procname       = "scons-poweroff",
 488                 .data           = &scons_pwroff,
 489                 .maxlen         = sizeof (int),
 490                 .mode           = 0644,
 491                 .proc_handler   = proc_dointvec,
 492         },
 493 #endif
 494 #ifdef CONFIG_SPARC64
 495         {
 496                 .procname       = "tsb-ratio",
 497                 .data           = &sysctl_tsb_ratio,
 498                 .maxlen         = sizeof (int),
 499                 .mode           = 0644,
 500                 .proc_handler   = proc_dointvec,
 501         },
 502 #endif
 503 #ifdef __hppa__
 504         {
 505                 .procname       = "soft-power",
 506                 .data           = &pwrsw_enabled,
 507                 .maxlen         = sizeof (int),
 508                 .mode           = 0644,
 509                 .proc_handler   = proc_dointvec,
 510         },
 511         {
 512                 .procname       = "unaligned-trap",
 513                 .data           = &unaligned_enabled,
 514                 .maxlen         = sizeof (int),
 515                 .mode           = 0644,
 516                 .proc_handler   = proc_dointvec,
 517         },
 518 #endif
 519         {
 520                 .procname       = "ctrl-alt-del",
 521                 .data           = &C_A_D,
 522                 .maxlen         = sizeof(int),
 523                 .mode           = 0644,
 524                 .proc_handler   = proc_dointvec,
 525         },
 526 #ifdef CONFIG_FUNCTION_TRACER
 527         {
 528                 .procname       = "ftrace_enabled",
 529                 .data           = &ftrace_enabled,
 530                 .maxlen         = sizeof(int),
 531                 .mode           = 0644,
 532                 .proc_handler   = ftrace_enable_sysctl,
 533         },
 534 #endif
 535 #ifdef CONFIG_STACK_TRACER
 536         {
 537                 .procname       = "stack_tracer_enabled",
 538                 .data           = &stack_tracer_enabled,
 539                 .maxlen         = sizeof(int),
 540                 .mode           = 0644,
 541                 .proc_handler   = stack_trace_sysctl,
 542         },
 543 #endif
 544 #ifdef CONFIG_TRACING
 545         {
 546                 .procname       = "ftrace_dump_on_oops",
 547                 .data           = &ftrace_dump_on_oops,
 548                 .maxlen         = sizeof(int),
 549                 .mode           = 0644,
 550                 .proc_handler   = proc_dointvec,
 551         },
 552 #endif
 553 #ifdef CONFIG_MODULES
 554         {
 555                 .procname       = "modprobe",
 556                 .data           = &modprobe_path,
 557                 .maxlen         = KMOD_PATH_LEN,
 558                 .mode           = 0644,
 559                 .proc_handler   = proc_dostring,
 560         },
 561         {
 562                 .procname       = "modules_disabled",
 563                 .data           = &modules_disabled,
 564                 .maxlen         = sizeof(int),
 565                 .mode           = 0644,
 566                 /* only handle a transition from default "0" to "1" */
 567                 .proc_handler   = proc_dointvec_minmax,
 568                 .extra1         = &one,
 569                 .extra2         = &one,
 570         },
 571 #endif
 572 #ifdef CONFIG_HOTPLUG
 573         {
 574                 .procname       = "hotplug",
 575                 .data           = &uevent_helper,
 576                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 577                 .mode           = 0644,
 578                 .proc_handler   = proc_dostring,
 579         },
 580 #endif
 581 #ifdef CONFIG_CHR_DEV_SG
 582         {
 583                 .procname       = "sg-big-buff",
 584                 .data           = &sg_big_buff,
 585                 .maxlen         = sizeof (int),
 586                 .mode           = 0444,
 587                 .proc_handler   = proc_dointvec,
 588         },
 589 #endif
 590 #ifdef CONFIG_BSD_PROCESS_ACCT
 591         {
 592                 .procname       = "acct",
 593                 .data           = &acct_parm,
 594                 .maxlen         = 3*sizeof(int),
 595                 .mode           = 0644,
 596                 .proc_handler   = proc_dointvec,
 597         },
 598 #endif
 599 #ifdef CONFIG_MAGIC_SYSRQ
 600         {
 601                 .procname       = "sysrq",
 602                 .data           = &__sysrq_enabled,
 603                 .maxlen         = sizeof (int),
 604                 .mode           = 0644,
 605                 .proc_handler   = sysrq_sysctl_handler,
 606         },
 607 #endif
 608 #ifdef CONFIG_PROC_SYSCTL
 609         {
 610                 .procname       = "cad_pid",
 611                 .data           = NULL,
 612                 .maxlen         = sizeof (int),
 613                 .mode           = 0600,
 614                 .proc_handler   = proc_do_cad_pid,
 615         },
 616 #endif
 617         {
 618                 .procname       = "threads-max",
 619                 .data           = &max_threads,
 620                 .maxlen         = sizeof(int),
 621                 .mode           = 0644,
 622                 .proc_handler   = proc_dointvec,
 623         },
 624         {
 625                 .procname       = "random",
 626                 .mode           = 0555,
 627                 .child          = random_table,
 628         },
 629         {
 630                 .procname       = "usermodehelper",
 631                 .mode           = 0555,
 632                 .child          = usermodehelper_table,
 633         },
 634         {
 635                 .procname       = "overflowuid",
 636                 .data           = &overflowuid,
 637                 .maxlen         = sizeof(int),
 638                 .mode           = 0644,
 639                 .proc_handler   = proc_dointvec_minmax,
 640                 .extra1         = &minolduid,
 641                 .extra2         = &maxolduid,
 642         },
 643         {
 644                 .procname       = "overflowgid",
 645                 .data           = &overflowgid,
 646                 .maxlen         = sizeof(int),
 647                 .mode           = 0644,
 648                 .proc_handler   = proc_dointvec_minmax,
 649                 .extra1         = &minolduid,
 650                 .extra2         = &maxolduid,
 651         },
 652 #ifdef CONFIG_S390
 653 #ifdef CONFIG_MATHEMU
 654         {
 655                 .procname       = "ieee_emulation_warnings",
 656                 .data           = &sysctl_ieee_emulation_warnings,
 657                 .maxlen         = sizeof(int),
 658                 .mode           = 0644,
 659                 .proc_handler   = proc_dointvec,
 660         },
 661 #endif
 662         {
 663                 .procname       = "userprocess_debug",
 664                 .data           = &show_unhandled_signals,
 665                 .maxlen         = sizeof(int),
 666                 .mode           = 0644,
 667                 .proc_handler   = proc_dointvec,
 668         },
 669 #endif
 670         {
 671                 .procname       = "pid_max",
 672                 .data           = &pid_max,
 673                 .maxlen         = sizeof (int),
 674                 .mode           = 0644,
 675                 .proc_handler   = proc_dointvec_minmax,
 676                 .extra1         = &pid_max_min,
 677                 .extra2         = &pid_max_max,
 678         },
 679         {
 680                 .procname       = "panic_on_oops",
 681                 .data           = &panic_on_oops,
 682                 .maxlen         = sizeof(int),
 683                 .mode           = 0644,
 684                 .proc_handler   = proc_dointvec,
 685         },
 686 #if defined CONFIG_PRINTK
 687         {
 688                 .procname       = "printk",
 689                 .data           = &console_loglevel,
 690                 .maxlen         = 4*sizeof(int),
 691                 .mode           = 0644,
 692                 .proc_handler   = proc_dointvec,
 693         },
 694         {
 695                 .procname       = "printk_ratelimit",
 696                 .data           = &printk_ratelimit_state.interval,
 697                 .maxlen         = sizeof(int),
 698                 .mode           = 0644,
 699                 .proc_handler   = proc_dointvec_jiffies,
 700         },
 701         {
 702                 .procname       = "printk_ratelimit_burst",
 703                 .data           = &printk_ratelimit_state.burst,
 704                 .maxlen         = sizeof(int),
 705                 .mode           = 0644,
 706                 .proc_handler   = proc_dointvec,
 707         },
 708         {
 709                 .procname       = "printk_delay",
 710                 .data           = &printk_delay_msec,
 711                 .maxlen         = sizeof(int),
 712                 .mode           = 0644,
 713                 .proc_handler   = proc_dointvec_minmax,
 714                 .extra1         = &zero,
 715                 .extra2         = &ten_thousand,
 716         },
 717         {
 718                 .procname       = "dmesg_restrict",
 719                 .data           = &dmesg_restrict,
 720                 .maxlen         = sizeof(int),
 721                 .mode           = 0644,
 722                 .proc_handler   = proc_dointvec_minmax,
 723                 .extra1         = &zero,
 724                 .extra2         = &one,
 725         },
 726         {
 727                 .procname       = "kptr_restrict",
 728                 .data           = &kptr_restrict,
 729                 .maxlen         = sizeof(int),
 730                 .mode           = 0644,
 731                 .proc_handler   = proc_dmesg_restrict,
 732                 .extra1         = &zero,
 733                 .extra2         = &two,
 734         },
 735 #endif
 736         {
 737                 .procname       = "ngroups_max",
 738                 .data           = &ngroups_max,
 739                 .maxlen         = sizeof (int),
 740                 .mode           = 0444,
 741                 .proc_handler   = proc_dointvec,
 742         },
 743 #if defined(CONFIG_LOCKUP_DETECTOR)
 744         {
 745                 .procname       = "watchdog",
 746                 .data           = &watchdog_enabled,
 747                 .maxlen         = sizeof (int),
 748                 .mode           = 0644,
 749                 .proc_handler   = proc_dowatchdog,
 750                 .extra1         = &zero,
 751                 .extra2         = &one,
 752         },
 753         {
 754                 .procname       = "watchdog_thresh",
 755                 .data           = &watchdog_thresh,
 756                 .maxlen         = sizeof(int),
 757                 .mode           = 0644,
 758                 .proc_handler   = proc_dowatchdog,
 759                 .extra1         = &neg_one,
 760                 .extra2         = &sixty,
 761         },
 762         {
 763                 .procname       = "softlockup_panic",
 764                 .data           = &softlockup_panic,
 765                 .maxlen         = sizeof(int),
 766                 .mode           = 0644,
 767                 .proc_handler   = proc_dointvec_minmax,
 768                 .extra1         = &zero,
 769                 .extra2         = &one,
 770         },
 771         {
 772                 .procname       = "nmi_watchdog",
 773                 .data           = &watchdog_enabled,
 774                 .maxlen         = sizeof (int),
 775                 .mode           = 0644,
 776                 .proc_handler   = proc_dowatchdog,
 777                 .extra1         = &zero,
 778                 .extra2         = &one,
 779         },
 780 #endif
 781 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 782         {
 783                 .procname       = "unknown_nmi_panic",
 784                 .data           = &unknown_nmi_panic,
 785                 .maxlen         = sizeof (int),
 786                 .mode           = 0644,
 787                 .proc_handler   = proc_dointvec,
 788         },
 789 #endif
 790 #if defined(CONFIG_X86)
 791         {
 792                 .procname       = "panic_on_unrecovered_nmi",
 793                 .data           = &panic_on_unrecovered_nmi,
 794                 .maxlen         = sizeof(int),
 795                 .mode           = 0644,
 796                 .proc_handler   = proc_dointvec,
 797         },
 798         {
 799                 .procname       = "panic_on_io_nmi",
 800                 .data           = &panic_on_io_nmi,
 801                 .maxlen         = sizeof(int),
 802                 .mode           = 0644,
 803                 .proc_handler   = proc_dointvec,
 804         },
 805         {
 806                 .procname       = "bootloader_type",
 807                 .data           = &bootloader_type,
 808                 .maxlen         = sizeof (int),
 809                 .mode           = 0444,
 810                 .proc_handler   = proc_dointvec,
 811         },
 812         {
 813                 .procname       = "bootloader_version",
 814                 .data           = &bootloader_version,
 815                 .maxlen         = sizeof (int),
 816                 .mode           = 0444,
 817                 .proc_handler   = proc_dointvec,
 818         },
 819         {
 820                 .procname       = "kstack_depth_to_print",
 821                 .data           = &kstack_depth_to_print,
 822                 .maxlen         = sizeof(int),
 823                 .mode           = 0644,
 824                 .proc_handler   = proc_dointvec,
 825         },
 826         {
 827                 .procname       = "io_delay_type",
 828                 .data           = &io_delay_type,
 829                 .maxlen         = sizeof(int),
 830                 .mode           = 0644,
 831                 .proc_handler   = proc_dointvec,
 832         },
 833 #endif
 834 #if defined(CONFIG_MMU)
 835         {
 836                 .procname       = "randomize_va_space",
 837                 .data           = &randomize_va_space,
 838                 .maxlen         = sizeof(int),
 839                 .mode           = 0644,
 840                 .proc_handler   = proc_dointvec,
 841         },
 842 #endif
 843 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 844         {
 845                 .procname       = "spin_retry",
 846                 .data           = &spin_retry,
 847                 .maxlen         = sizeof (int),
 848                 .mode           = 0644,
 849                 .proc_handler   = proc_dointvec,
 850         },
 851 #endif
 852 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 853         {
 854                 .procname       = "acpi_video_flags",
 855                 .data           = &acpi_realmode_flags,
 856                 .maxlen         = sizeof (unsigned long),
 857                 .mode           = 0644,
 858                 .proc_handler   = proc_doulongvec_minmax,
 859         },
 860 #endif
 861 #ifdef CONFIG_IA64
 862         {
 863                 .procname       = "ignore-unaligned-usertrap",
 864                 .data           = &no_unaligned_warning,
 865                 .maxlen         = sizeof (int),
 866                 .mode           = 0644,
 867                 .proc_handler   = proc_dointvec,
 868         },
 869         {
 870                 .procname       = "unaligned-dump-stack",
 871                 .data           = &unaligned_dump_stack,
 872                 .maxlen         = sizeof (int),
 873                 .mode           = 0644,
 874                 .proc_handler   = proc_dointvec,
 875         },
 876 #endif
 877 #ifdef CONFIG_DETECT_HUNG_TASK
 878         {
 879                 .procname       = "hung_task_panic",
 880                 .data           = &sysctl_hung_task_panic,
 881                 .maxlen         = sizeof(int),
 882                 .mode           = 0644,
 883                 .proc_handler   = proc_dointvec_minmax,
 884                 .extra1         = &zero,
 885                 .extra2         = &one,
 886         },
 887         {
 888                 .procname       = "hung_task_check_count",
 889                 .data           = &sysctl_hung_task_check_count,
 890                 .maxlen         = sizeof(unsigned long),
 891                 .mode           = 0644,
 892                 .proc_handler   = proc_doulongvec_minmax,
 893         },
 894         {
 895                 .procname       = "hung_task_timeout_secs",
 896                 .data           = &sysctl_hung_task_timeout_secs,
 897                 .maxlen         = sizeof(unsigned long),
 898                 .mode           = 0644,
 899                 .proc_handler   = proc_dohung_task_timeout_secs,
 900         },
 901         {
 902                 .procname       = "hung_task_warnings",
 903                 .data           = &sysctl_hung_task_warnings,
 904                 .maxlen         = sizeof(unsigned long),
 905                 .mode           = 0644,
 906                 .proc_handler   = proc_doulongvec_minmax,
 907         },
 908 #endif
 909 #ifdef CONFIG_COMPAT
 910         {
 911                 .procname       = "compat-log",
 912                 .data           = &compat_log,
 913                 .maxlen         = sizeof (int),
 914                 .mode           = 0644,
 915                 .proc_handler   = proc_dointvec,
 916         },
 917 #endif
 918 #ifdef CONFIG_RT_MUTEXES
 919         {
 920                 .procname       = "max_lock_depth",
 921                 .data           = &max_lock_depth,
 922                 .maxlen         = sizeof(int),
 923                 .mode           = 0644,
 924                 .proc_handler   = proc_dointvec,
 925         },
 926 #endif
 927         {
 928                 .procname       = "poweroff_cmd",
 929                 .data           = &poweroff_cmd,
 930                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 931                 .mode           = 0644,
 932                 .proc_handler   = proc_dostring,
 933         },
 934 #ifdef CONFIG_KEYS
 935         {
 936                 .procname       = "keys",
 937                 .mode           = 0555,
 938                 .child          = key_sysctls,
 939         },
 940 #endif
 941 #ifdef CONFIG_RCU_TORTURE_TEST
 942         {
 943                 .procname       = "rcutorture_runnable",
 944                 .data           = &rcutorture_runnable,
 945                 .maxlen         = sizeof(int),
 946                 .mode           = 0644,
 947                 .proc_handler   = proc_dointvec,
 948         },
 949 #endif
 950 #ifdef CONFIG_PERF_EVENTS
 951         /*
 952          * User-space scripts rely on the existence of this file
 953          * as a feature check for perf_events being enabled.
 954          *
 955          * So it's an ABI, do not remove!
 956          */
 957         {
 958                 .procname       = "perf_event_paranoid",
 959                 .data           = &sysctl_perf_event_paranoid,
 960                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 961                 .mode           = 0644,
 962                 .proc_handler   = proc_dointvec,
 963         },
 964         {
 965                 .procname       = "perf_event_mlock_kb",
 966                 .data           = &sysctl_perf_event_mlock,
 967                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 968                 .mode           = 0644,
 969                 .proc_handler   = proc_dointvec,
 970         },
 971         {
 972                 .procname       = "perf_event_max_sample_rate",
 973                 .data           = &sysctl_perf_event_sample_rate,
 974                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 975                 .mode           = 0644,
 976                 .proc_handler   = perf_proc_update_handler,
 977         },
 978 #endif
 979 #ifdef CONFIG_KMEMCHECK
 980         {
 981                 .procname       = "kmemcheck",
 982                 .data           = &kmemcheck_enabled,
 983                 .maxlen         = sizeof(int),
 984                 .mode           = 0644,
 985                 .proc_handler   = proc_dointvec,
 986         },
 987 #endif
 988 #ifdef CONFIG_BLOCK
 989         {
 990                 .procname       = "blk_iopoll",
 991                 .data           = &blk_iopoll_enabled,
 992                 .maxlen         = sizeof(int),
 993                 .mode           = 0644,
 994                 .proc_handler   = proc_dointvec,
 995         },
 996 #endif
 997         { }
 998 };
 999
1000 static struct ctl_table vm_table[] = {
1001         {
1002                 .procname       = "overcommit_memory",
1003                 .data           = &sysctl_overcommit_memory,
1004                 .maxlen         = sizeof(sysctl_overcommit_memory),
1005                 .mode           = 0644,
1006                 .proc_handler   = proc_dointvec_minmax,
1007                 .extra1         = &zero,
1008                 .extra2         = &two,
1009         },
1010         {
1011                 .procname       = "panic_on_oom",
1012                 .data           = &sysctl_panic_on_oom,
1013                 .maxlen         = sizeof(sysctl_panic_on_oom),
1014                 .mode           = 0644,
1015                 .proc_handler   = proc_dointvec_minmax,
1016                 .extra1         = &zero,
1017                 .extra2         = &two,
1018         },
1019         {
1020                 .procname       = "oom_kill_allocating_task",
1021                 .data           = &sysctl_oom_kill_allocating_task,
1022                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1023                 .mode           = 0644,
1024                 .proc_handler   = proc_dointvec,
1025         },
1026         {
1027                 .procname       = "oom_dump_tasks",
1028                 .data           = &sysctl_oom_dump_tasks,
1029                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1030                 .mode           = 0644,
1031                 .proc_handler   = proc_dointvec,
1032         },
1033         {
1034                 .procname       = "overcommit_ratio",
1035                 .data           = &sysctl_overcommit_ratio,
1036                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1037                 .mode           = 0644,
1038                 .proc_handler   = proc_dointvec,
1039         },
1040         {
1041                 .procname       = "page-cluster",
1042                 .data           = &page_cluster,
1043                 .maxlen         = sizeof(int),
1044                 .mode           = 0644,
1045                 .proc_handler   = proc_dointvec_minmax,
1046                 .extra1         = &zero,
1047         },
1048         {
1049                 .procname       = "dirty_background_ratio",
1050                 .data           = &dirty_background_ratio,
1051                 .maxlen         = sizeof(dirty_background_ratio),
1052                 .mode           = 0644,
1053                 .proc_handler   = dirty_background_ratio_handler,
1054                 .extra1         = &zero,
1055                 .extra2         = &one_hundred,
1056         },
1057         {
1058                 .procname       = "dirty_background_bytes",
1059                 .data           = &dirty_background_bytes,
1060                 .maxlen         = sizeof(dirty_background_bytes),
1061                 .mode           = 0644,
1062                 .proc_handler   = dirty_background_bytes_handler,
1063                 .extra1         = &one_ul,
1064         },
1065         {
1066                 .procname       = "dirty_ratio",
1067                 .data           = &vm_dirty_ratio,
1068                 .maxlen         = sizeof(vm_dirty_ratio),
1069                 .mode           = 0644,
1070                 .proc_handler   = dirty_ratio_handler,
1071                 .extra1         = &zero,
1072                 .extra2         = &one_hundred,
1073         },
1074         {
1075                 .procname       = "dirty_bytes",
1076                 .data           = &vm_dirty_bytes,
1077                 .maxlen         = sizeof(vm_dirty_bytes),
1078                 .mode           = 0644,
1079                 .proc_handler   = dirty_bytes_handler,
1080                 .extra1         = &dirty_bytes_min,
1081         },
1082         {
1083                 .procname       = "dirty_writeback_centisecs",
1084                 .data           = &dirty_writeback_interval,
1085                 .maxlen         = sizeof(dirty_writeback_interval),
1086                 .mode           = 0644,
1087                 .proc_handler   = dirty_writeback_centisecs_handler,
1088         },
1089         {
1090                 .procname       = "dirty_expire_centisecs",
1091                 .data           = &dirty_expire_interval,
1092                 .maxlen         = sizeof(dirty_expire_interval),
1093                 .mode           = 0644,
1094                 .proc_handler   = proc_dointvec_minmax,
1095                 .extra1         = &zero,
1096         },
1097         {
1098                 .procname       = "nr_pdflush_threads",
1099                 .data           = &nr_pdflush_threads,
1100                 .maxlen         = sizeof nr_pdflush_threads,
1101                 .mode           = 0444 /* read-only*/,
1102                 .proc_handler   = proc_dointvec,
1103         },
1104         {
1105                 .procname       = "swappiness",
1106                 .data           = &vm_swappiness,
1107                 .maxlen         = sizeof(vm_swappiness),
1108                 .mode           = 0644,
1109                 .proc_handler   = proc_dointvec_minmax,
1110                 .extra1         = &zero,
1111                 .extra2         = &one_hundred,
1112         },
1113 #ifdef CONFIG_HUGETLB_PAGE
1114         {
1115                 .procname       = "nr_hugepages",
1116                 .data           = NULL,
1117                 .maxlen         = sizeof(unsigned long),
1118                 .mode           = 0644,
1119                 .proc_handler   = hugetlb_sysctl_handler,
1120                 .extra1         = (void *)&hugetlb_zero,
1121                 .extra2         = (void *)&hugetlb_infinity,
1122         },
1123 #ifdef CONFIG_NUMA
1124         {
1125                 .procname       = "nr_hugepages_mempolicy",
1126                 .data           = NULL,
1127                 .maxlen         = sizeof(unsigned long),
1128                 .mode           = 0644,
1129                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1130                 .extra1         = (void *)&hugetlb_zero,
1131                 .extra2         = (void *)&hugetlb_infinity,
1132         },
1133 #endif
1134          {
1135                 .procname       = "hugetlb_shm_group",
1136                 .data           = &sysctl_hugetlb_shm_group,
1137                 .maxlen         = sizeof(gid_t),
1138                 .mode           = 0644,
1139                 .proc_handler   = proc_dointvec,
1140          },
1141          {
1142                 .procname       = "hugepages_treat_as_movable",
1143                 .data           = &hugepages_treat_as_movable,
1144                 .maxlen         = sizeof(int),
1145                 .mode           = 0644,
1146                 .proc_handler   = hugetlb_treat_movable_handler,
1147         },
1148         {
1149                 .procname       = "nr_overcommit_hugepages",
1150                 .data           = NULL,
1151                 .maxlen         = sizeof(unsigned long),
1152                 .mode           = 0644,
1153                 .proc_handler   = hugetlb_overcommit_handler,
1154                 .extra1         = (void *)&hugetlb_zero,
1155                 .extra2         = (void *)&hugetlb_infinity,
1156         },
1157 #endif
1158         {
1159                 .procname       = "lowmem_reserve_ratio",
1160                 .data           = &sysctl_lowmem_reserve_ratio,
1161                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1162                 .mode           = 0644,
1163                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1164         },
1165         {
1166                 .procname       = "drop_caches",
1167                 .data           = &sysctl_drop_caches,
1168                 .maxlen         = sizeof(int),
1169                 .mode           = 0644,
1170                 .proc_handler   = drop_caches_sysctl_handler,
1171                 .extra1         = &one,
1172                 .extra2         = &three,
1173         },
1174 #ifdef CONFIG_COMPACTION
1175         {
1176                 .procname       = "compact_memory",
1177                 .data           = &sysctl_compact_memory,
1178                 .maxlen         = sizeof(int),
1179                 .mode           = 0200,
1180                 .proc_handler   = sysctl_compaction_handler,
1181         },
1182         {
1183                 .procname       = "extfrag_threshold",
1184                 .data           = &sysctl_extfrag_threshold,
1185                 .maxlen         = sizeof(int),
1186                 .mode           = 0644,
1187                 .proc_handler   = sysctl_extfrag_handler,
1188                 .extra1         = &min_extfrag_threshold,
1189                 .extra2         = &max_extfrag_threshold,
1190         },
1191
1192 #endif /* CONFIG_COMPACTION */
1193         {
1194                 .procname       = "min_free_kbytes",
1195                 .data           = &min_free_kbytes,
1196                 .maxlen         = sizeof(min_free_kbytes),
1197                 .mode           = 0644,
1198                 .proc_handler   = min_free_kbytes_sysctl_handler,
1199                 .extra1         = &zero,
1200         },
1201         {
1202                 .procname       = "percpu_pagelist_fraction",
1203                 .data           = &percpu_pagelist_fraction,
1204                 .maxlen         = sizeof(percpu_pagelist_fraction),
1205                 .mode           = 0644,
1206                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1207                 .extra1         = &min_percpu_pagelist_fract,
1208         },
1209 #ifdef CONFIG_MMU
1210         {
1211                 .procname       = "max_map_count",
1212                 .data           = &sysctl_max_map_count,
1213                 .maxlen         = sizeof(sysctl_max_map_count),
1214                 .mode           = 0644,
1215                 .proc_handler   = proc_dointvec_minmax,
1216                 .extra1         = &zero,
1217         },
1218 #else
1219         {
1220                 .procname       = "nr_trim_pages",
1221                 .data           = &sysctl_nr_trim_pages,
1222                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1223                 .mode           = 0644,
1224                 .proc_handler   = proc_dointvec_minmax,
1225                 .extra1         = &zero,
1226         },
1227 #endif
1228         {
1229                 .procname       = "laptop_mode",
1230                 .data           = &laptop_mode,
1231                 .maxlen         = sizeof(laptop_mode),
1232                 .mode           = 0644,
1233                 .proc_handler   = proc_dointvec_jiffies,
1234         },
1235         {
1236                 .procname       = "block_dump",
1237                 .data           = &block_dump,
1238                 .maxlen         = sizeof(block_dump),
1239                 .mode           = 0644,
1240                 .proc_handler   = proc_dointvec,
1241                 .extra1         = &zero,
1242         },
1243         {
1244                 .procname       = "vfs_cache_pressure",
1245                 .data           = &sysctl_vfs_cache_pressure,
1246                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1247                 .mode           = 0644,
1248                 .proc_handler   = proc_dointvec,
1249                 .extra1         = &zero,
1250         },
1251 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1252         {
1253                 .procname       = "legacy_va_layout",
1254                 .data           = &sysctl_legacy_va_layout,
1255                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1256                 .mode           = 0644,
1257                 .proc_handler   = proc_dointvec,
1258                 .extra1         = &zero,
1259         },
1260 #endif
1261 #ifdef CONFIG_NUMA
1262         {
1263                 .procname       = "zone_reclaim_mode",
1264                 .data           = &zone_reclaim_mode,
1265                 .maxlen         = sizeof(zone_reclaim_mode),
1266                 .mode           = 0644,
1267                 .proc_handler   = proc_dointvec,
1268                 .extra1         = &zero,
1269         },
1270         {
1271                 .procname       = "min_unmapped_ratio",
1272                 .data           = &sysctl_min_unmapped_ratio,
1273                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1274                 .mode           = 0644,
1275                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1276                 .extra1         = &zero,
1277                 .extra2         = &one_hundred,
1278         },
1279         {
1280                 .procname       = "min_slab_ratio",
1281                 .data           = &sysctl_min_slab_ratio,
1282                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1283                 .mode           = 0644,
1284                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1285                 .extra1         = &zero,
1286                 .extra2         = &one_hundred,
1287         },
1288 #endif
1289 #ifdef CONFIG_SMP
1290         {
1291                 .procname       = "stat_interval",
1292                 .data           = &sysctl_stat_interval,
1293                 .maxlen         = sizeof(sysctl_stat_interval),
1294                 .mode           = 0644,
1295                 .proc_handler   = proc_dointvec_jiffies,
1296         },
1297 #endif
1298 #ifdef CONFIG_MMU
1299         {
1300                 .procname       = "mmap_min_addr",
1301                 .data           = &dac_mmap_min_addr,
1302                 .maxlen         = sizeof(unsigned long),
1303                 .mode           = 0644,
1304                 .proc_handler   = mmap_min_addr_handler,
1305         },
1306 #endif
1307 #ifdef CONFIG_NUMA
1308         {
1309                 .procname       = "numa_zonelist_order",
1310                 .data           = &numa_zonelist_order,
1311                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1312                 .mode           = 0644,
1313                 .proc_handler   = numa_zonelist_order_handler,
1314         },
1315 #endif
1316 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1317    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1318         {
1319                 .procname       = "vdso_enabled",
1320                 .data           = &vdso_enabled,
1321                 .maxlen         = sizeof(vdso_enabled),
1322                 .mode           = 0644,
1323                 .proc_handler   = proc_dointvec,
1324                 .extra1         = &zero,
1325         },
1326 #endif
1327 #ifdef CONFIG_HIGHMEM
1328         {
1329                 .procname       = "highmem_is_dirtyable",
1330                 .data           = &vm_highmem_is_dirtyable,
1331                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1332                 .mode           = 0644,
1333                 .proc_handler   = proc_dointvec_minmax,
1334                 .extra1         = &zero,
1335                 .extra2         = &one,
1336         },
1337 #endif
1338         {
1339                 .procname       = "scan_unevictable_pages",
1340                 .data           = &scan_unevictable_pages,
1341                 .maxlen         = sizeof(scan_unevictable_pages),
1342                 .mode           = 0644,
1343                 .proc_handler   = scan_unevictable_handler,
1344         },
1345 #ifdef CONFIG_MEMORY_FAILURE
1346         {
1347                 .procname       = "memory_failure_early_kill",
1348                 .data           = &sysctl_memory_failure_early_kill,
1349                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1350                 .mode           = 0644,
1351                 .proc_handler   = proc_dointvec_minmax,
1352                 .extra1         = &zero,
1353                 .extra2         = &one,
1354         },
1355         {
1356                 .procname       = "memory_failure_recovery",
1357                 .data           = &sysctl_memory_failure_recovery,
1358                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1359                 .mode           = 0644,
1360                 .proc_handler   = proc_dointvec_minmax,
1361                 .extra1         = &zero,
1362                 .extra2         = &one,
1363         },
1364 #endif
1365         { }
1366 };
1367
1368 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1369 static struct ctl_table binfmt_misc_table[] = {
1370         { }
1371 };
1372 #endif
1373
1374 static struct ctl_table fs_table[] = {
1375         {
1376                 .procname       = "inode-nr",
1377                 .data           = &inodes_stat,
1378                 .maxlen         = 2*sizeof(int),
1379                 .mode           = 0444,
1380                 .proc_handler   = proc_nr_inodes,
1381         },
1382         {
1383                 .procname       = "inode-state",
1384                 .data           = &inodes_stat,
1385                 .maxlen         = 7*sizeof(int),
1386                 .mode           = 0444,
1387                 .proc_handler   = proc_nr_inodes,
1388         },
1389         {
1390                 .procname       = "file-nr",
1391                 .data           = &files_stat,
1392                 .maxlen         = sizeof(files_stat),
1393                 .mode           = 0444,
1394                 .proc_handler   = proc_nr_files,
1395         },
1396         {
1397                 .procname       = "file-max",
1398                 .data           = &files_stat.max_files,
1399                 .maxlen         = sizeof(files_stat.max_files),
1400                 .mode           = 0644,
1401                 .proc_handler   = proc_doulongvec_minmax,
1402         },
1403         {
1404                 .procname       = "nr_open",
1405                 .data           = &sysctl_nr_open,
1406                 .maxlen         = sizeof(int),
1407                 .mode           = 0644,
1408                 .proc_handler   = proc_dointvec_minmax,
1409                 .extra1         = &sysctl_nr_open_min,
1410                 .extra2         = &sysctl_nr_open_max,
1411         },
1412         {
1413                 .procname       = "dentry-state",
1414                 .data           = &dentry_stat,
1415                 .maxlen         = 6*sizeof(int),
1416                 .mode           = 0444,
1417                 .proc_handler   = proc_nr_dentry,
1418         },
1419         {
1420                 .procname       = "overflowuid",
1421                 .data           = &fs_overflowuid,
1422                 .maxlen         = sizeof(int),
1423                 .mode           = 0644,
1424                 .proc_handler   = proc_dointvec_minmax,
1425                 .extra1         = &minolduid,
1426                 .extra2         = &maxolduid,
1427         },
1428         {
1429                 .procname       = "overflowgid",
1430                 .data           = &fs_overflowgid,
1431                 .maxlen         = sizeof(int),
1432                 .mode           = 0644,
1433                 .proc_handler   = proc_dointvec_minmax,
1434                 .extra1         = &minolduid,
1435                 .extra2         = &maxolduid,
1436         },
1437 #ifdef CONFIG_FILE_LOCKING
1438         {
1439                 .procname       = "leases-enable",
1440                 .data           = &leases_enable,
1441                 .maxlen         = sizeof(int),
1442                 .mode           = 0644,
1443                 .proc_handler   = proc_dointvec,
1444         },
1445 #endif
1446 #ifdef CONFIG_DNOTIFY
1447         {
1448                 .procname       = "dir-notify-enable",
1449                 .data           = &dir_notify_enable,
1450                 .maxlen         = sizeof(int),
1451                 .mode           = 0644,
1452                 .proc_handler   = proc_dointvec,
1453         },
1454 #endif
1455 #ifdef CONFIG_MMU
1456 #ifdef CONFIG_FILE_LOCKING
1457         {
1458                 .procname       = "lease-break-time",
1459                 .data           = &lease_break_time,
1460                 .maxlen         = sizeof(int),
1461                 .mode           = 0644,
1462                 .proc_handler   = proc_dointvec,
1463         },
1464 #endif
1465 #ifdef CONFIG_AIO
1466         {
1467                 .procname       = "aio-nr",
1468                 .data           = &aio_nr,
1469                 .maxlen         = sizeof(aio_nr),
1470                 .mode           = 0444,
1471                 .proc_handler   = proc_doulongvec_minmax,
1472         },
1473         {
1474                 .procname       = "aio-max-nr",
1475                 .data           = &aio_max_nr,
1476                 .maxlen         = sizeof(aio_max_nr),
1477                 .mode           = 0644,
1478                 .proc_handler   = proc_doulongvec_minmax,
1479         },
1480 #endif /* CONFIG_AIO */
1481 #ifdef CONFIG_INOTIFY_USER
1482         {
1483                 .procname       = "inotify",
1484                 .mode           = 0555,
1485                 .child          = inotify_table,
1486         },
1487 #endif
1488 #ifdef CONFIG_EPOLL
1489         {
1490                 .procname       = "epoll",
1491                 .mode           = 0555,
1492                 .child          = epoll_table,
1493         },
1494 #endif
1495 #endif
1496         {
1497                 .procname       = "suid_dumpable",
1498                 .data           = &suid_dumpable,
1499                 .maxlen         = sizeof(int),
1500                 .mode           = 0644,
1501                 .proc_handler   = proc_dointvec_minmax,
1502                 .extra1         = &zero,
1503                 .extra2         = &two,
1504         },
1505 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1506         {
1507                 .procname       = "binfmt_misc",
1508                 .mode           = 0555,
1509                 .child          = binfmt_misc_table,
1510         },
1511 #endif
1512         {
1513                 .procname       = "pipe-max-size",
1514                 .data           = &pipe_max_size,
1515                 .maxlen         = sizeof(int),
1516                 .mode           = 0644,
1517                 .proc_handler   = &pipe_proc_fn,
1518                 .extra1         = &pipe_min_size,
1519         },
1520         { }
1521 };
1522
1523 static struct ctl_table debug_table[] = {
1524 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1525     defined(CONFIG_S390) || defined(CONFIG_TILE)
1526         {
1527                 .procname       = "exception-trace",
1528                 .data           = &show_unhandled_signals,
1529                 .maxlen         = sizeof(int),
1530                 .mode           = 0644,
1531                 .proc_handler   = proc_dointvec
1532         },
1533 #endif
1534 #if defined(CONFIG_OPTPROBES)
1535         {
1536                 .procname       = "kprobes-optimization",
1537                 .data           = &sysctl_kprobes_optimization,
1538                 .maxlen         = sizeof(int),
1539                 .mode           = 0644,
1540                 .proc_handler   = proc_kprobes_optimization_handler,
1541                 .extra1         = &zero,
1542                 .extra2         = &one,
1543         },
1544 #endif
1545         { }
1546 };
1547
1548 static struct ctl_table dev_table[] = {
1549         { }
1550 };
1551
1552 static DEFINE_SPINLOCK(sysctl_lock);
1553
1554 /* called under sysctl_lock */
1555 static int use_table(struct ctl_table_header *p)
1556 {
1557         if (unlikely(p->unregistering))
1558                 return 0;
1559         p->used++;
1560         return 1;
1561 }
1562
1563 /* called under sysctl_lock */
1564 static void unuse_table(struct ctl_table_header *p)
1565 {
1566         if (!--p->used)
1567                 if (unlikely(p->unregistering))
1568                         complete(p->unregistering);
1569 }
1570
1571 /* called under sysctl_lock, will reacquire if has to wait */
1572 static void start_unregistering(struct ctl_table_header *p)
1573 {
1574         /*
1575          * if p->used is 0, nobody will ever touch that entry again;
1576          * we'll eliminate all paths to it before dropping sysctl_lock
1577          */
1578         if (unlikely(p->used)) {
1579                 struct completion wait;
1580                 init_completion(&wait);
1581                 p->unregistering = &wait;
1582                 spin_unlock(&sysctl_lock);
1583                 wait_for_completion(&wait);
1584                 spin_lock(&sysctl_lock);
1585         } else {
1586                 /* anything non-NULL; we'll never dereference it */
1587                 p->unregistering = ERR_PTR(-EINVAL);
1588         }
1589         /*
1590          * do not remove from the list until nobody holds it; walking the
1591          * list in do_sysctl() relies on that.
1592          */
1593         list_del_init(&p->ctl_entry);
1594 }
1595
1596 void sysctl_head_get(struct ctl_table_header *head)
1597 {
1598         spin_lock(&sysctl_lock);
1599         head->count++;
1600         spin_unlock(&sysctl_lock);
1601 }
1602
1603 void sysctl_head_put(struct ctl_table_header *head)
1604 {
1605         spin_lock(&sysctl_lock);
1606         if (!--head->count)
1607                 kfree_rcu(head, rcu);
1608         spin_unlock(&sysctl_lock);
1609 }
1610
1611 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1612 {
1613         if (!head)
1614                 BUG();
1615         spin_lock(&sysctl_lock);
1616         if (!use_table(head))
1617                 head = ERR_PTR(-ENOENT);
1618         spin_unlock(&sysctl_lock);
1619         return head;
1620 }
1621
1622 void sysctl_head_finish(struct ctl_table_header *head)
1623 {
1624         if (!head)
1625                 return;
1626         spin_lock(&sysctl_lock);
1627         unuse_table(head);
1628         spin_unlock(&sysctl_lock);
1629 }
1630
1631 static struct ctl_table_set *
1632 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1633 {
1634         struct ctl_table_set *set = &root->default_set;
1635         if (root->lookup)
1636                 set = root->lookup(root, namespaces);
1637         return set;
1638 }
1639
1640 static struct list_head *
1641 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1642 {
1643         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1644         return &set->list;
1645 }
1646
1647 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1648                                             struct ctl_table_header *prev)
1649 {
1650         struct ctl_table_root *root;
1651         struct list_head *header_list;
1652         struct ctl_table_header *head;
1653         struct list_head *tmp;
1654
1655         spin_lock(&sysctl_lock);
1656         if (prev) {
1657                 head = prev;
1658                 tmp = &prev->ctl_entry;
1659                 unuse_table(prev);
1660                 goto next;
1661         }
1662         tmp = &root_table_header.ctl_entry;
1663         for (;;) {
1664                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1665
1666                 if (!use_table(head))
1667                         goto next;
1668                 spin_unlock(&sysctl_lock);
1669                 return head;
1670         next:
1671                 root = head->root;
1672                 tmp = tmp->next;
1673                 header_list = lookup_header_list(root, namespaces);
1674                 if (tmp != header_list)
1675                         continue;
1676
1677                 do {
1678                         root = list_entry(root->root_list.next,
1679                                         struct ctl_table_root, root_list);
1680                         if (root == &sysctl_table_root)
1681                                 goto out;
1682                         header_list = lookup_header_list(root, namespaces);
1683                 } while (list_empty(header_list));
1684                 tmp = header_list->next;
1685         }
1686 out:
1687         spin_unlock(&sysctl_lock);
1688         return NULL;
1689 }
1690
1691 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1692 {
1693         return __sysctl_head_next(current->nsproxy, prev);
1694 }
1695
1696 void register_sysctl_root(struct ctl_table_root *root)
1697 {
1698         spin_lock(&sysctl_lock);
1699         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1700         spin_unlock(&sysctl_lock);
1701 }
1702
1703 /*
1704  * sysctl_perm does NOT grant the superuser all rights automatically, because
1705  * some sysctl variables are readonly even to root.
1706  */
1707
1708 static int test_perm(int mode, int op)
1709 {
1710         if (!current_euid())
1711                 mode >>= 6;
1712         else if (in_egroup_p(0))
1713                 mode >>= 3;
1714         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1715                 return 0;
1716         return -EACCES;
1717 }
1718
1719 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1720 {
1721         int mode;
1722
1723         if (root->permissions)
1724                 mode = root->permissions(root, current->nsproxy, table);
1725         else
1726                 mode = table->mode;
1727
1728         return test_perm(mode, op);
1729 }
1730
1731 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1732 {
1733         for (; table->procname; table++) {
1734                 table->parent = parent;
1735                 if (table->child)
1736                         sysctl_set_parent(table, table->child);
1737         }
1738 }
1739
1740 static __init int sysctl_init(void)
1741 {
1742         sysctl_set_parent(NULL, root_table);
1743 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1744         sysctl_check_table(current->nsproxy, root_table);
1745 #endif
1746         return 0;
1747 }
1748
1749 core_initcall(sysctl_init);
1750
1751 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1752                                       struct ctl_table *table)
1753 {
1754         struct ctl_table *p;
1755         const char *s = branch->procname;
1756
1757         /* branch should have named subdirectory as its first element */
1758         if (!s || !branch->child)
1759                 return NULL;
1760
1761         /* ... and nothing else */
1762         if (branch[1].procname)
1763                 return NULL;
1764
1765         /* table should contain subdirectory with the same name */
1766         for (p = table; p->procname; p++) {
1767                 if (!p->child)
1768                         continue;
1769                 if (p->procname && strcmp(p->procname, s) == 0)
1770                         return p;
1771         }
1772         return NULL;
1773 }
1774
1775 /* see if attaching q to p would be an improvement */
1776 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1777 {
1778         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1779         struct ctl_table *next;
1780         int is_better = 0;
1781         int not_in_parent = !p->attached_by;
1782
1783         while ((next = is_branch_in(by, to)) != NULL) {
1784                 if (by == q->attached_by)
1785                         is_better = 1;
1786                 if (to == p->attached_by)
1787                         not_in_parent = 1;
1788                 by = by->child;
1789                 to = next->child;
1790         }
1791
1792         if (is_better && not_in_parent) {
1793                 q->attached_by = by;
1794                 q->attached_to = to;
1795                 q->parent = p;
1796         }
1797 }
1798
1799 /**
1800  * __register_sysctl_paths - register a sysctl hierarchy
1801  * @root: List of sysctl headers to register on
1802  * @namespaces: Data to compute which lists of sysctl entries are visible
1803  * @path: The path to the directory the sysctl table is in.
1804  * @table: the top-level table structure
1805  *
1806  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1807  * array. A completely 0 filled entry terminates the table.
1808  *
1809  * The members of the &struct ctl_table structure are used as follows:
1810  *
1811  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1812  *            enter a sysctl file
1813  *
1814  * data - a pointer to data for use by proc_handler
1815  *
1816  * maxlen - the maximum size in bytes of the data
1817  *
1818  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1819  *
1820  * child - a pointer to the child sysctl table if this entry is a directory, or
1821  *         %NULL.
1822  *
1823  * proc_handler - the text handler routine (described below)
1824  *
1825  * de - for internal use by the sysctl routines
1826  *
1827  * extra1, extra2 - extra pointers usable by the proc handler routines
1828  *
1829  * Leaf nodes in the sysctl tree will be represented by a single file
1830  * under /proc; non-leaf nodes will be represented by directories.
1831  *
1832  * sysctl(2) can automatically manage read and write requests through
1833  * the sysctl table.  The data and maxlen fields of the ctl_table
1834  * struct enable minimal validation of the values being written to be
1835  * performed, and the mode field allows minimal authentication.
1836  *
1837  * There must be a proc_handler routine for any terminal nodes
1838  * mirrored under /proc/sys (non-terminals are handled by a built-in
1839  * directory handler).  Several default handlers are available to
1840  * cover common cases -
1841  *
1842  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1843  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1844  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1845  *
1846  * It is the handler's job to read the input buffer from user memory
1847  * and process it. The handler should return 0 on success.
1848  *
1849  * This routine returns %NULL on a failure to register, and a pointer
1850  * to the table header on success.
1851  */
1852 struct ctl_table_header *__register_sysctl_paths(
1853         struct ctl_table_root *root,
1854         struct nsproxy *namespaces,
1855         const struct ctl_path *path, struct ctl_table *table)
1856 {
1857         struct ctl_table_header *header;
1858         struct ctl_table *new, **prevp;
1859         unsigned int n, npath;
1860         struct ctl_table_set *set;
1861
1862         /* Count the path components */
1863         for (npath = 0; path[npath].procname; ++npath)
1864                 ;
1865
1866         /*
1867          * For each path component, allocate a 2-element ctl_table array.
1868          * The first array element will be filled with the sysctl entry
1869          * for this, the second will be the sentinel (procname == 0).
1870          *
1871          * We allocate everything in one go so that we don't have to
1872          * worry about freeing additional memory in unregister_sysctl_table.
1873          */
1874         header = kzalloc(sizeof(struct ctl_table_header) +
1875                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1876         if (!header)
1877                 return NULL;
1878
1879         new = (struct ctl_table *) (header + 1);
1880
1881         /* Now connect the dots */
1882         prevp = &header->ctl_table;
1883         for (n = 0; n < npath; ++n, ++path) {
1884                 /* Copy the procname */
1885                 new->procname = path->procname;
1886                 new->mode     = 0555;
1887
1888                 *prevp = new;
1889                 prevp = &new->child;
1890
1891                 new += 2;
1892         }
1893         *prevp = table;
1894         header->ctl_table_arg = table;
1895
1896         INIT_LIST_HEAD(&header->ctl_entry);
1897         header->used = 0;
1898         header->unregistering = NULL;
1899         header->root = root;
1900         sysctl_set_parent(NULL, header->ctl_table);
1901         header->count = 1;
1902 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1903         if (sysctl_check_table(namespaces, header->ctl_table)) {
1904                 kfree(header);
1905                 return NULL;
1906         }
1907 #endif
1908         spin_lock(&sysctl_lock);
1909         header->set = lookup_header_set(root, namespaces);
1910         header->attached_by = header->ctl_table;
1911         header->attached_to = root_table;
1912         header->parent = &root_table_header;
1913         for (set = header->set; set; set = set->parent) {
1914                 struct ctl_table_header *p;
1915                 list_for_each_entry(p, &set->list, ctl_entry) {
1916                         if (p->unregistering)
1917                                 continue;
1918                         try_attach(p, header);
1919                 }
1920         }
1921         header->parent->count++;
1922         list_add_tail(&header->ctl_entry, &header->set->list);
1923         spin_unlock(&sysctl_lock);
1924
1925         return header;
1926 }
1927
1928 /**
1929  * register_sysctl_table_path - register a sysctl table hierarchy
1930  * @path: The path to the directory the sysctl table is in.
1931  * @table: the top-level table structure
1932  *
1933  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1934  * array. A completely 0 filled entry terminates the table.
1935  *
1936  * See __register_sysctl_paths for more details.
1937  */
1938 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1939                                                 struct ctl_table *table)
1940 {
1941         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1942                                         path, table);
1943 }
1944
1945 /**
1946  * register_sysctl_table - register a sysctl table hierarchy
1947  * @table: the top-level table structure
1948  *
1949  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1950  * array. A completely 0 filled entry terminates the table.
1951  *
1952  * See register_sysctl_paths for more details.
1953  */
1954 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1955 {
1956         static const struct ctl_path null_path[] = { {} };
1957
1958         return register_sysctl_paths(null_path, table);
1959 }
1960
1961 /**
1962  * unregister_sysctl_table - unregister a sysctl table hierarchy
1963  * @header: the header returned from register_sysctl_table
1964  *
1965  * Unregisters the sysctl table and all children. proc entries may not
1966  * actually be removed until they are no longer used by anyone.
1967  */
1968 void unregister_sysctl_table(struct ctl_table_header * header)
1969 {
1970         might_sleep();
1971
1972         if (header == NULL)
1973                 return;
1974
1975         spin_lock(&sysctl_lock);
1976         start_unregistering(header);
1977         if (!--header->parent->count) {
1978                 WARN_ON(1);
1979                 kfree_rcu(header->parent, rcu);
1980         }
1981         if (!--header->count)
1982                 kfree_rcu(header, rcu);
1983         spin_unlock(&sysctl_lock);
1984 }
1985
1986 int sysctl_is_seen(struct ctl_table_header *p)
1987 {
1988         struct ctl_table_set *set = p->set;
1989         int res;
1990         spin_lock(&sysctl_lock);
1991         if (p->unregistering)
1992                 res = 0;
1993         else if (!set->is_seen)
1994                 res = 1;
1995         else
1996                 res = set->is_seen(set);
1997         spin_unlock(&sysctl_lock);
1998         return res;
1999 }
2000
2001 void setup_sysctl_set(struct ctl_table_set *p,
2002         struct ctl_table_set *parent,
2003         int (*is_seen)(struct ctl_table_set *))
2004 {
2005         INIT_LIST_HEAD(&p->list);
2006         p->parent = parent ? parent : &sysctl_table_root.default_set;
2007         p->is_seen = is_seen;
2008 }
2009
2010 #else /* !CONFIG_SYSCTL */
2011 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2012 {
2013         return NULL;
2014 }
2015
2016 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2017                                                     struct ctl_table *table)
2018 {
2019         return NULL;
2020 }
2021
2022 void unregister_sysctl_table(struct ctl_table_header * table)
2023 {
2024 }
2025
2026 void setup_sysctl_set(struct ctl_table_set *p,
2027         struct ctl_table_set *parent,
2028         int (*is_seen)(struct ctl_table_set *))
2029 {
2030 }
2031
2032 void sysctl_head_put(struct ctl_table_header *head)
2033 {
2034 }
2035
2036 #endif /* CONFIG_SYSCTL */
2037
2038 /*
2039  * /proc/sys support
2040  */
2041
2042 #ifdef CONFIG_PROC_SYSCTL
2043
2044 static int _proc_do_string(void* data, int maxlen, int write,
2045                            void __user *buffer,
2046                            size_t *lenp, loff_t *ppos)
2047 {
2048         size_t len;
2049         char __user *p;
2050         char c;
2051
2052         if (!data || !maxlen || !*lenp) {
2053                 *lenp = 0;
2054                 return 0;
2055         }
2056
2057         if (write) {
2058                 len = 0;
2059                 p = buffer;
2060                 while (len < *lenp) {
2061                         if (get_user(c, p++))
2062                                 return -EFAULT;
2063                         if (c == 0 || c == '\n')
2064                                 break;
2065                         len++;
2066                 }
2067                 if (len >= maxlen)
2068                         len = maxlen-1;
2069                 if(copy_from_user(data, buffer, len))
2070                         return -EFAULT;
2071                 ((char *) data)[len] = 0;
2072                 *ppos += *lenp;
2073         } else {
2074                 len = strlen(data);
2075                 if (len > maxlen)
2076                         len = maxlen;
2077
2078                 if (*ppos > len) {
2079                         *lenp = 0;
2080                         return 0;
2081                 }
2082
2083                 data += *ppos;
2084                 len  -= *ppos;
2085
2086                 if (len > *lenp)
2087                         len = *lenp;
2088                 if (len)
2089                         if(copy_to_user(buffer, data, len))
2090                                 return -EFAULT;
2091                 if (len < *lenp) {
2092                         if(put_user('\n', ((char __user *) buffer) + len))
2093                                 return -EFAULT;
2094                         len++;
2095                 }
2096                 *lenp = len;
2097                 *ppos += len;
2098         }
2099         return 0;
2100 }
2101
2102 /**
2103  * proc_dostring - read a string sysctl
2104  * @table: the sysctl table
2105  * @write: %TRUE if this is a write to the sysctl file
2106  * @buffer: the user buffer
2107  * @lenp: the size of the user buffer
2108  * @ppos: file position
2109  *
2110  * Reads/writes a string from/to the user buffer. If the kernel
2111  * buffer provided is not large enough to hold the string, the
2112  * string is truncated. The copied string is %NULL-terminated.
2113  * If the string is being read by the user process, it is copied
2114  * and a newline '\n' is added. It is truncated if the buffer is
2115  * not large enough.
2116  *
2117  * Returns 0 on success.
2118  */
2119 int proc_dostring(struct ctl_table *table, int write,
2120                   void __user *buffer, size_t *lenp, loff_t *ppos)
2121 {
2122         return _proc_do_string(table->data, table->maxlen, write,
2123                                buffer, lenp, ppos);
2124 }
2125
2126 static size_t proc_skip_spaces(char **buf)
2127 {
2128         size_t ret;
2129         char *tmp = skip_spaces(*buf);
2130         ret = tmp - *buf;
2131         *buf = tmp;
2132         return ret;
2133 }
2134
2135 static void proc_skip_char(char **buf, size_t *size, const char v)
2136 {
2137         while (*size) {
2138                 if (**buf != v)
2139                         break;
2140                 (*size)--;
2141                 (*buf)++;
2142         }
2143 }
2144
2145 #define TMPBUFLEN 22
2146 /**
2147  * proc_get_long - reads an ASCII formatted integer from a user buffer
2148  *
2149  * @buf: a kernel buffer
2150  * @size: size of the kernel buffer
2151  * @val: this is where the number will be stored
2152  * @neg: set to %TRUE if number is negative
2153  * @perm_tr: a vector which contains the allowed trailers
2154  * @perm_tr_len: size of the perm_tr vector
2155  * @tr: pointer to store the trailer character
2156  *
2157  * In case of success %0 is returned and @buf and @size are updated with
2158  * the amount of bytes read. If @tr is non-NULL and a trailing
2159  * character exists (size is non-zero after returning from this
2160  * function), @tr is updated with the trailing character.
2161  */
2162 static int proc_get_long(char **buf, size_t *size,
2163                           unsigned long *val, bool *neg,
2164                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2165 {
2166         int len;
2167         char *p, tmp[TMPBUFLEN];
2168
2169         if (!*size)
2170                 return -EINVAL;
2171
2172         len = *size;
2173         if (len > TMPBUFLEN - 1)
2174                 len = TMPBUFLEN - 1;
2175
2176         memcpy(tmp, *buf, len);
2177
2178         tmp[len] = 0;
2179         p = tmp;
2180         if (*p == '-' && *size > 1) {
2181                 *neg = true;
2182                 p++;
2183         } else
2184                 *neg = false;
2185         if (!isdigit(*p))
2186                 return -EINVAL;
2187
2188         *val = simple_strtoul(p, &p, 0);
2189
2190         len = p - tmp;
2191
2192         /* We don't know if the next char is whitespace thus we may accept
2193          * invalid integers (e.g. 1234...a) or two integers instead of one
2194          * (e.g. 123...1). So lets not allow such large numbers. */
2195         if (len == TMPBUFLEN - 1)
2196                 return -EINVAL;
2197
2198         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2199                 return -EINVAL;
2200
2201         if (tr && (len < *size))
2202                 *tr = *p;
2203
2204         *buf += len;
2205         *size -= len;
2206
2207         return 0;
2208 }
2209
2210 /**
2211  * proc_put_long - converts an integer to a decimal ASCII formatted string
2212  *
2213  * @buf: the user buffer
2214  * @size: the size of the user buffer
2215  * @val: the integer to be converted
2216  * @neg: sign of the number, %TRUE for negative
2217  *
2218  * In case of success %0 is returned and @buf and @size are updated with
2219  * the amount of bytes written.
2220  */
2221 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2222                           bool neg)
2223 {
2224         int len;
2225         char tmp[TMPBUFLEN], *p = tmp;
2226
2227         sprintf(p, "%s%lu", neg ? "-" : "", val);
2228         len = strlen(tmp);
2229         if (len > *size)
2230                 len = *size;
2231         if (copy_to_user(*buf, tmp, len))
2232                 return -EFAULT;
2233         *size -= len;
2234         *buf += len;
2235         return 0;
2236 }
2237 #undef TMPBUFLEN
2238
2239 static int proc_put_char(void __user **buf, size_t *size, char c)
2240 {
2241         if (*size) {
2242                 char __user **buffer = (char __user **)buf;
2243                 if (put_user(c, *buffer))
2244                         return -EFAULT;
2245                 (*size)--, (*buffer)++;
2246                 *buf = *buffer;
2247         }
2248         return 0;
2249 }
2250
2251 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2252                                  int *valp,
2253                                  int write, void *data)
2254 {
2255         if (write) {
2256                 *valp = *negp ? -*lvalp : *lvalp;
2257         } else {
2258                 int val = *valp;
2259                 if (val < 0) {
2260                         *negp = true;
2261                         *lvalp = (unsigned long)-val;
2262                 } else {
2263                         *negp = false;
2264                         *lvalp = (unsigned long)val;
2265                 }
2266         }
2267         return 0;
2268 }
2269
2270 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2271
2272 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2273                   int write, void __user *buffer,
2274                   size_t *lenp, loff_t *ppos,
2275                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2276                               int write, void *data),
2277                   void *data)
2278 {
2279         int *i, vleft, first = 1, err = 0;
2280         unsigned long page = 0;
2281         size_t left;
2282         char *kbuf;
2283
2284         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2285                 *lenp = 0;
2286                 return 0;
2287         }
2288
2289         i = (int *) tbl_data;
2290         vleft = table->maxlen / sizeof(*i);
2291         left = *lenp;
2292
2293         if (!conv)
2294                 conv = do_proc_dointvec_conv;
2295
2296         if (write) {
2297                 if (left > PAGE_SIZE - 1)
2298                         left = PAGE_SIZE - 1;
2299                 page = __get_free_page(GFP_TEMPORARY);
2300                 kbuf = (char *) page;
2301                 if (!kbuf)
2302                         return -ENOMEM;
2303                 if (copy_from_user(kbuf, buffer, left)) {
2304                         err = -EFAULT;
2305                         goto free;
2306                 }
2307                 kbuf[left] = 0;
2308         }
2309
2310         for (; left && vleft--; i++, first=0) {
2311                 unsigned long lval;
2312                 bool neg;
2313
2314                 if (write) {
2315                         left -= proc_skip_spaces(&kbuf);
2316
2317                         if (!left)
2318                                 break;
2319                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2320                                              proc_wspace_sep,
2321                                              sizeof(proc_wspace_sep), NULL);
2322                         if (err)
2323                                 break;
2324                         if (conv(&neg, &lval, i, 1, data)) {
2325                                 err = -EINVAL;
2326                                 break;
2327                         }
2328                 } else {
2329                         if (conv(&neg, &lval, i, 0, data)) {
2330                                 err = -EINVAL;
2331                                 break;
2332                         }
2333                         if (!first)
2334                                 err = proc_put_char(&buffer, &left, '\t');
2335                         if (err)
2336                                 break;
2337                         err = proc_put_long(&buffer, &left, lval, neg);
2338                         if (err)
2339                                 break;
2340                 }
2341         }
2342
2343         if (!write && !first && left && !err)
2344                 err = proc_put_char(&buffer, &left, '\n');
2345         if (write && !err && left)
2346                 left -= proc_skip_spaces(&kbuf);
2347 free:
2348         if (write) {
2349                 free_page(page);
2350                 if (first)
2351                         return err ? : -EINVAL;
2352         }
2353         *lenp -= left;
2354         *ppos += *lenp;
2355         return err;
2356 }
2357
2358 static int do_proc_dointvec(struct ctl_table *table, int write,
2359                   void __user *buffer, size_t *lenp, loff_t *ppos,
2360                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2361                               int write, void *data),
2362                   void *data)
2363 {
2364         return __do_proc_dointvec(table->data, table, write,
2365                         buffer, lenp, ppos, conv, data);
2366 }
2367
2368 /**
2369  * proc_dointvec - read a vector of integers
2370  * @table: the sysctl table
2371  * @write: %TRUE if this is a write to the sysctl file
2372  * @buffer: the user buffer
2373  * @lenp: the size of the user buffer
2374  * @ppos: file position
2375  *
2376  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2377  * values from/to the user buffer, treated as an ASCII string.
2378  *
2379  * Returns 0 on success.
2380  */
2381 int proc_dointvec(struct ctl_table *table, int write,
2382                      void __user *buffer, size_t *lenp, loff_t *ppos)
2383 {
2384     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2385                             NULL,NULL);
2386 }
2387
2388 /*
2389  * Taint values can only be increased
2390  * This means we can safely use a temporary.
2391  */
2392 static int proc_taint(struct ctl_table *table, int write,
2393                                void __user *buffer, size_t *lenp, loff_t *ppos)
2394 {
2395         struct ctl_table t;
2396         unsigned long tmptaint = get_taint();
2397         int err;
2398
2399         if (write && !capable(CAP_SYS_ADMIN))
2400                 return -EPERM;
2401
2402         t = *table;
2403         t.data = &tmptaint;
2404         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2405         if (err < 0)
2406                 return err;
2407
2408         if (write) {
2409                 /*
2410                  * Poor man's atomic or. Not worth adding a primitive
2411                  * to everyone's atomic.h for this
2412                  */
2413                 int i;
2414                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2415                         if ((tmptaint >> i) & 1)
2416                                 add_taint(i);
2417                 }
2418         }
2419
2420         return err;
2421 }
2422
2423 #ifdef CONFIG_PRINTK
2424 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2425                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2426 {
2427         if (write && !capable(CAP_SYS_ADMIN))
2428                 return -EPERM;
2429
2430         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2431 }
2432 #endif
2433
2434 struct do_proc_dointvec_minmax_conv_param {
2435         int *min;
2436         int *max;
2437 };
2438
2439 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2440                                         int *valp,
2441                                         int write, void *data)
2442 {
2443         struct do_proc_dointvec_minmax_conv_param *param = data;
2444         if (write) {
2445                 int val = *negp ? -*lvalp : *lvalp;
2446                 if ((param->min && *param->min > val) ||
2447                     (param->max && *param->max < val))
2448                         return -EINVAL;
2449                 *valp = val;
2450         } else {
2451                 int val = *valp;
2452                 if (val < 0) {
2453                         *negp = true;
2454                         *lvalp = (unsigned long)-val;
2455                 } else {
2456                         *negp = false;
2457                         *lvalp = (unsigned long)val;
2458                 }
2459         }
2460         return 0;
2461 }
2462
2463 /**
2464  * proc_dointvec_minmax - read a vector of integers with min/max values
2465  * @table: the sysctl table
2466  * @write: %TRUE if this is a write to the sysctl file
2467  * @buffer: the user buffer
2468  * @lenp: the size of the user buffer
2469  * @ppos: file position
2470  *
2471  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2472  * values from/to the user buffer, treated as an ASCII string.
2473  *
2474  * This routine will ensure the values are within the range specified by
2475  * table->extra1 (min) and table->extra2 (max).
2476  *
2477  * Returns 0 on success.
2478  */
2479 int proc_dointvec_minmax(struct ctl_table *table, int write,
2480                   void __user *buffer, size_t *lenp, loff_t *ppos)
2481 {
2482         struct do_proc_dointvec_minmax_conv_param param = {
2483                 .min = (int *) table->extra1,
2484                 .max = (int *) table->extra2,
2485         };
2486         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2487                                 do_proc_dointvec_minmax_conv, &param);
2488 }
2489
2490 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2491                                      void __user *buffer,
2492                                      size_t *lenp, loff_t *ppos,
2493                                      unsigned long convmul,
2494                                      unsigned long convdiv)
2495 {
2496         unsigned long *i, *min, *max;
2497         int vleft, first = 1, err = 0;
2498         unsigned long page = 0;
2499         size_t left;
2500         char *kbuf;
2501
2502         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2503                 *lenp = 0;
2504                 return 0;
2505         }
2506
2507         i = (unsigned long *) data;
2508         min = (unsigned long *) table->extra1;
2509         max = (unsigned long *) table->extra2;
2510         vleft = table->maxlen / sizeof(unsigned long);
2511         left = *lenp;
2512
2513         if (write) {
2514                 if (left > PAGE_SIZE - 1)
2515                         left = PAGE_SIZE - 1;
2516                 page = __get_free_page(GFP_TEMPORARY);
2517                 kbuf = (char *) page;
2518                 if (!kbuf)
2519                         return -ENOMEM;
2520                 if (copy_from_user(kbuf, buffer, left)) {
2521                         err = -EFAULT;
2522                         goto free;
2523                 }
2524                 kbuf[left] = 0;
2525         }
2526
2527         for (; left && vleft--; i++, first = 0) {
2528                 unsigned long val;
2529
2530                 if (write) {
2531                         bool neg;
2532
2533                         left -= proc_skip_spaces(&kbuf);
2534
2535                         err = proc_get_long(&kbuf, &left, &val, &neg,
2536                                              proc_wspace_sep,
2537                                              sizeof(proc_wspace_sep), NULL);
2538                         if (err)
2539                                 break;
2540                         if (neg)
2541                                 continue;
2542                         if ((min && val < *min) || (max && val > *max))
2543                                 continue;
2544                         *i = val;
2545                 } else {
2546                         val = convdiv * (*i) / convmul;
2547                         if (!first)
2548                                 err = proc_put_char(&buffer, &left, '\t');
2549                         err = proc_put_long(&buffer, &left, val, false);
2550                         if (err)
2551                                 break;
2552                 }
2553         }
2554
2555         if (!write && !first && left && !err)
2556                 err = proc_put_char(&buffer, &left, '\n');
2557         if (write && !err)
2558                 left -= proc_skip_spaces(&kbuf);
2559 free:
2560         if (write) {
2561                 free_page(page);
2562                 if (first)
2563                         return err ? : -EINVAL;
2564         }
2565         *lenp -= left;
2566         *ppos += *lenp;
2567         return err;
2568 }
2569
2570 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2571                                      void __user *buffer,
2572                                      size_t *lenp, loff_t *ppos,
2573                                      unsigned long convmul,
2574                                      unsigned long convdiv)
2575 {
2576         return __do_proc_doulongvec_minmax(table->data, table, write,
2577                         buffer, lenp, ppos, convmul, convdiv);
2578 }
2579
2580 /**
2581  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2582  * @table: the sysctl table
2583  * @write: %TRUE if this is a write to the sysctl file
2584  * @buffer: the user buffer
2585  * @lenp: the size of the user buffer
2586  * @ppos: file position
2587  *
2588  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2589  * values from/to the user buffer, treated as an ASCII string.
2590  *
2591  * This routine will ensure the values are within the range specified by
2592  * table->extra1 (min) and table->extra2 (max).
2593  *
2594  * Returns 0 on success.
2595  */
2596 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2597                            void __user *buffer, size_t *lenp, loff_t *ppos)
2598 {
2599     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2600 }
2601
2602 /**
2603  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2604  * @table: the sysctl table
2605  * @write: %TRUE if this is a write to the sysctl file
2606  * @buffer: the user buffer
2607  * @lenp: the size of the user buffer
2608  * @ppos: file position
2609  *
2610  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2611  * values from/to the user buffer, treated as an ASCII string. The values
2612  * are treated as milliseconds, and converted to jiffies when they are stored.
2613  *
2614  * This routine will ensure the values are within the range specified by
2615  * table->extra1 (min) and table->extra2 (max).
2616  *
2617  * Returns 0 on success.
2618  */
2619 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2620                                       void __user *buffer,
2621                                       size_t *lenp, loff_t *ppos)
2622 {
2623     return do_proc_doulongvec_minmax(table, write, buffer,
2624                                      lenp, ppos, HZ, 1000l);
2625 }
2626
2627
2628 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2629                                          int *valp,
2630                                          int write, void *data)
2631 {
2632         if (write) {
2633                 if (*lvalp > LONG_MAX / HZ)
2634                         return 1;
2635                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2636         } else {
2637                 int val = *valp;
2638                 unsigned long lval;
2639                 if (val < 0) {
2640                         *negp = true;
2641                         lval = (unsigned long)-val;
2642                 } else {
2643                         *negp = false;
2644                         lval = (unsigned long)val;
2645                 }
2646                 *lvalp = lval / HZ;
2647         }
2648         return 0;
2649 }
2650
2651 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2652                                                 int *valp,
2653                                                 int write, void *data)
2654 {
2655         if (write) {
2656                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2657                         return 1;
2658                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2659         } else {
2660                 int val = *valp;
2661                 unsigned long lval;
2662                 if (val < 0) {
2663                         *negp = true;
2664                         lval = (unsigned long)-val;
2665                 } else {
2666                         *negp = false;
2667                         lval = (unsigned long)val;
2668                 }
2669                 *lvalp = jiffies_to_clock_t(lval);
2670         }
2671         return 0;
2672 }
2673
2674 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2675                                             int *valp,
2676                                             int write, void *data)
2677 {
2678         if (write) {
2679                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2680         } else {
2681                 int val = *valp;
2682                 unsigned long lval;
2683                 if (val < 0) {
2684                         *negp = true;
2685                         lval = (unsigned long)-val;
2686                 } else {
2687                         *negp = false;
2688                         lval = (unsigned long)val;
2689                 }
2690                 *lvalp = jiffies_to_msecs(lval);
2691         }
2692         return 0;
2693 }
2694
2695 /**
2696  * proc_dointvec_jiffies - read a vector of integers as seconds
2697  * @table: the sysctl table
2698  * @write: %TRUE if this is a write to the sysctl file
2699  * @buffer: the user buffer
2700  * @lenp: the size of the user buffer
2701  * @ppos: file position
2702  *
2703  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2704  * values from/to the user buffer, treated as an ASCII string.
2705  * The values read are assumed to be in seconds, and are converted into
2706  * jiffies.
2707  *
2708  * Returns 0 on success.
2709  */
2710 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2711                           void __user *buffer, size_t *lenp, loff_t *ppos)
2712 {
2713     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2714                             do_proc_dointvec_jiffies_conv,NULL);
2715 }
2716
2717 /**
2718  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2719  * @table: the sysctl table
2720  * @write: %TRUE if this is a write to the sysctl file
2721  * @buffer: the user buffer
2722  * @lenp: the size of the user buffer
2723  * @ppos: pointer to the file position
2724  *
2725  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2726  * values from/to the user buffer, treated as an ASCII string.
2727  * The values read are assumed to be in 1/USER_HZ seconds, and
2728  * are converted into jiffies.
2729  *
2730  * Returns 0 on success.
2731  */
2732 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2733                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2734 {
2735     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2736                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2737 }
2738
2739 /**
2740  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2741  * @table: the sysctl table
2742  * @write: %TRUE if this is a write to the sysctl file
2743  * @buffer: the user buffer
2744  * @lenp: the size of the user buffer
2745  * @ppos: file position
2746  * @ppos: the current position in the file
2747  *
2748  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2749  * values from/to the user buffer, treated as an ASCII string.
2750  * The values read are assumed to be in 1/1000 seconds, and
2751  * are converted into jiffies.
2752  *
2753  * Returns 0 on success.
2754  */
2755 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2756                              void __user *buffer, size_t *lenp, loff_t *ppos)
2757 {
2758         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2759                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2760 }
2761
2762 static int proc_do_cad_pid(struct ctl_table *table, int write,
2763                            void __user *buffer, size_t *lenp, loff_t *ppos)
2764 {
2765         struct pid *new_pid;
2766         pid_t tmp;
2767         int r;
2768
2769         tmp = pid_vnr(cad_pid);
2770
2771         r = __do_proc_dointvec(&tmp, table, write, buffer,
2772                                lenp, ppos, NULL, NULL);
2773         if (r || !write)
2774                 return r;
2775
2776         new_pid = find_get_pid(tmp);
2777         if (!new_pid)
2778                 return -ESRCH;
2779
2780         put_pid(xchg(&cad_pid, new_pid));
2781         return 0;
2782 }
2783
2784 /**
2785  * proc_do_large_bitmap - read/write from/to a large bitmap
2786  * @table: the sysctl table
2787  * @write: %TRUE if this is a write to the sysctl file
2788  * @buffer: the user buffer
2789  * @lenp: the size of the user buffer
2790  * @ppos: file position
2791  *
2792  * The bitmap is stored at table->data and the bitmap length (in bits)
2793  * in table->maxlen.
2794  *
2795  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2796  * large bitmaps may be represented in a compact manner. Writing into
2797  * the file will clear the bitmap then update it with the given input.
2798  *
2799  * Returns 0 on success.
2800  */
2801 int proc_do_large_bitmap(struct ctl_table *table, int write,
2802                          void __user *buffer, size_t *lenp, loff_t *ppos)
2803 {
2804         int err = 0;
2805         bool first = 1;
2806         size_t left = *lenp;
2807         unsigned long bitmap_len = table->maxlen;
2808         unsigned long *bitmap = (unsigned long *) table->data;
2809         unsigned long *tmp_bitmap = NULL;
2810         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2811
2812         if (!bitmap_len || !left || (*ppos && !write)) {
2813                 *lenp = 0;
2814                 return 0;
2815         }
2816
2817         if (write) {
2818                 unsigned long page = 0;
2819                 char *kbuf;
2820
2821                 if (left > PAGE_SIZE - 1)
2822                         left = PAGE_SIZE - 1;
2823
2824                 page = __get_free_page(GFP_TEMPORARY);
2825                 kbuf = (char *) page;
2826                 if (!kbuf)
2827                         return -ENOMEM;
2828                 if (copy_from_user(kbuf, buffer, left)) {
2829                         free_page(page);
2830                         return -EFAULT;
2831                 }
2832                 kbuf[left] = 0;
2833
2834                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2835                                      GFP_KERNEL);
2836                 if (!tmp_bitmap) {
2837                         free_page(page);
2838                         return -ENOMEM;
2839                 }
2840                 proc_skip_char(&kbuf, &left, '\n');
2841                 while (!err && left) {
2842                         unsigned long val_a, val_b;
2843                         bool neg;
2844
2845                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2846                                              sizeof(tr_a), &c);
2847                         if (err)
2848                                 break;
2849                         if (val_a >= bitmap_len || neg) {
2850                                 err = -EINVAL;
2851                                 break;
2852                         }
2853
2854                         val_b = val_a;
2855                         if (left) {
2856                                 kbuf++;
2857                                 left--;
2858                         }
2859
2860                         if (c == '-') {
2861                                 err = proc_get_long(&kbuf, &left, &val_b,
2862                                                      &neg, tr_b, sizeof(tr_b),
2863                                                      &c);
2864                                 if (err)
2865                                         break;
2866                                 if (val_b >= bitmap_len || neg ||
2867                                     val_a > val_b) {
2868                                         err = -EINVAL;
2869                                         break;
2870                                 }
2871                                 if (left) {
2872                                         kbuf++;
2873                                         left--;
2874                                 }
2875                         }
2876
2877                         while (val_a <= val_b)
2878                                 set_bit(val_a++, tmp_bitmap);
2879
2880                         first = 0;
2881                         proc_skip_char(&kbuf, &left, '\n');
2882                 }
2883                 free_page(page);
2884         } else {
2885                 unsigned long bit_a, bit_b = 0;
2886
2887                 while (left) {
2888                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2889                         if (bit_a >= bitmap_len)
2890                                 break;
2891                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2892                                                    bit_a + 1) - 1;
2893
2894                         if (!first) {
2895                                 err = proc_put_char(&buffer, &left, ',');
2896                                 if (err)
2897                                         break;
2898                         }
2899                         err = proc_put_long(&buffer, &left, bit_a, false);
2900                         if (err)
2901                                 break;
2902                         if (bit_a != bit_b) {
2903                                 err = proc_put_char(&buffer, &left, '-');
2904                                 if (err)
2905                                         break;
2906                                 err = proc_put_long(&buffer, &left, bit_b, false);
2907                                 if (err)
2908                                         break;
2909                         }
2910
2911                         first = 0; bit_b++;
2912                 }
2913                 if (!err)
2914                         err = proc_put_char(&buffer, &left, '\n');
2915         }
2916
2917         if (!err) {
2918                 if (write) {
2919                         if (*ppos)
2920                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2921                         else
2922                                 memcpy(bitmap, tmp_bitmap,
2923                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2924                 }
2925                 kfree(tmp_bitmap);
2926                 *lenp -= left;
2927                 *ppos += *lenp;
2928                 return 0;
2929         } else {
2930                 kfree(tmp_bitmap);
2931                 return err;
2932         }
2933 }
2934
2935 #else /* CONFIG_PROC_SYSCTL */
2936
2937 int proc_dostring(struct ctl_table *table, int write,
2938                   void __user *buffer, size_t *lenp, loff_t *ppos)
2939 {
2940         return -ENOSYS;
2941 }
2942
2943 int proc_dointvec(struct ctl_table *table, int write,
2944                   void __user *buffer, size_t *lenp, loff_t *ppos)
2945 {
2946         return -ENOSYS;
2947 }
2948
2949 int proc_dointvec_minmax(struct ctl_table *table, int write,
2950                     void __user *buffer, size_t *lenp, loff_t *ppos)
2951 {
2952         return -ENOSYS;
2953 }
2954
2955 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2956                     void __user *buffer, size_t *lenp, loff_t *ppos)
2957 {
2958         return -ENOSYS;
2959 }
2960
2961 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2962                     void __user *buffer, size_t *lenp, loff_t *ppos)
2963 {
2964         return -ENOSYS;
2965 }
2966
2967 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2968                              void __user *buffer, size_t *lenp, loff_t *ppos)
2969 {
2970         return -ENOSYS;
2971 }
2972
2973 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2974                     void __user *buffer, size_t *lenp, loff_t *ppos)
2975 {
2976         return -ENOSYS;
2977 }
2978
2979 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2980                                       void __user *buffer,
2981                                       size_t *lenp, loff_t *ppos)
2982 {
2983     return -ENOSYS;
2984 }
2985
2986
2987 #endif /* CONFIG_PROC_SYSCTL */
2988
2989 /*
2990  * No sense putting this after each symbol definition, twice,
2991  * exception granted :-)
2992  */
2993 EXPORT_SYMBOL(proc_dointvec);
2994 EXPORT_SYMBOL(proc_dointvec_jiffies);
2995 EXPORT_SYMBOL(proc_dointvec_minmax);
2996 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2997 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2998 EXPORT_SYMBOL(proc_dostring);
2999 EXPORT_SYMBOL(proc_doulongvec_minmax);
3000 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3001 EXPORT_SYMBOL(register_sysctl_table);
3002 EXPORT_SYMBOL(register_sysctl_paths);
3003 EXPORT_SYMBOL(unregister_sysctl_table);