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 #include <linux/capability.h>
  61 #include <linux/binfmts.h>
  62
  63 #include <asm/uaccess.h>
  64 #include <asm/processor.h>
  65
  66 #ifdef CONFIG_X86
  67 #include <asm/nmi.h>
  68 #include <asm/stacktrace.h>
  69 #include <asm/io.h>
  70 #endif
  71 #ifdef CONFIG_BSD_PROCESS_ACCT
  72 #include <linux/acct.h>
  73 #endif
  74 #ifdef CONFIG_RT_MUTEXES
  75 #include <linux/rtmutex.h>
  76 #endif
  77 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  78 #include <linux/lockdep.h>
  79 #endif
  80 #ifdef CONFIG_CHR_DEV_SG
  81 #include <scsi/sg.h>
  82 #endif
  83
  84 #ifdef CONFIG_LOCKUP_DETECTOR
  85 #include <linux/nmi.h>
  86 #endif
  87
  88
  89 #if defined(CONFIG_SYSCTL)
  90
  91 /* External variables not in a header file. */
  92 extern int sysctl_overcommit_memory;
  93 extern int sysctl_overcommit_ratio;
  94 extern int max_threads;
  95 extern int core_uses_pid;
  96 extern int suid_dumpable;
  97 extern char core_pattern[];
  98 extern unsigned int core_pipe_limit;
  99 extern int pid_max;
 100 extern int min_free_kbytes;
 101 extern int pid_max_min, pid_max_max;
 102 extern int sysctl_drop_caches;
 103 extern int percpu_pagelist_fraction;
 104 extern int compat_log;
 105 extern int latencytop_enabled;
 106 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 107 #ifndef CONFIG_MMU
 108 extern int sysctl_nr_trim_pages;
 109 #endif
 110 #ifdef CONFIG_BLOCK
 111 extern int blk_iopoll_enabled;
 112 #endif
 113
 114 /* Constants used for minimum and  maximum */
 115 #ifdef CONFIG_LOCKUP_DETECTOR
 116 static int sixty = 60;
 117 static int neg_one = -1;
 118 #endif
 119
 120 static int zero;
 121 static int __maybe_unused one = 1;
 122 static int __maybe_unused two = 2;
 123 static int __maybe_unused three = 3;
 124 static unsigned long one_ul = 1;
 125 static int one_hundred = 100;
 126 #ifdef CONFIG_PRINTK
 127 static int ten_thousand = 10000;
 128 #endif
 129
 130 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 131 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 132
 133 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 134 static int maxolduid = 65535;
 135 static int minolduid;
 136 static int min_percpu_pagelist_fract = 8;
 137
 138 static int ngroups_max = NGROUPS_MAX;
 139 static const int cap_last_cap = CAP_LAST_CAP;
 140
 141 #ifdef CONFIG_INOTIFY_USER
 142 #include <linux/inotify.h>
 143 #endif
 144 #ifdef CONFIG_SPARC
 145 #include <asm/system.h>
 146 #endif
 147
 148 #ifdef CONFIG_SPARC64
 149 extern int sysctl_tsb_ratio;
 150 #endif
 151
 152 #ifdef __hppa__
 153 extern int pwrsw_enabled;
 154 extern int unaligned_enabled;
 155 #endif
 156
 157 #ifdef CONFIG_IA64
 158 extern int no_unaligned_warning;
 159 extern int unaligned_dump_stack;
 160 #endif
 161
 162 #ifdef CONFIG_PROC_SYSCTL
 163 static int proc_do_cad_pid(struct ctl_table *table, int write,
 164                   void __user *buffer, size_t *lenp, loff_t *ppos);
 165 static int proc_taint(struct ctl_table *table, int write,
 166                                void __user *buffer, size_t *lenp, loff_t *ppos);
 167 #endif
 168
 169 #ifdef CONFIG_PRINTK
 170 static int proc_dmesg_restrict(struct ctl_table *table, int write,
 171                                 void __user *buffer, size_t *lenp, loff_t *ppos);
 172 #endif
 173
 174 #ifdef CONFIG_MAGIC_SYSRQ
 175 /* Note: sysrq code uses it's own private copy */
 176 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
 177
 178 static int sysrq_sysctl_handler(ctl_table *table, int write,
 179                                 void __user *buffer, size_t *lenp,
 180                                 loff_t *ppos)
 181 {
 182         int error;
 183
 184         error = proc_dointvec(table, write, buffer, lenp, ppos);
 185         if (error)
 186                 return error;
 187
 188         if (write)
 189                 sysrq_toggle_support(__sysrq_enabled);
 190
 191         return 0;
 192 }
 193
 194 #endif
 195
 196 static struct ctl_table root_table[];
 197 static struct ctl_table_root sysctl_table_root;
 198 static struct ctl_table_header root_table_header = {
 199         {{.count = 1,
 200         .ctl_table = root_table,
 201         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
 202         .root = &sysctl_table_root,
 203         .set = &sysctl_table_root.default_set,
 204 };
 205 static struct ctl_table_root sysctl_table_root = {
 206         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 207         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 208 };
 209
 210 static struct ctl_table kern_table[];
 211 static struct ctl_table vm_table[];
 212 static struct ctl_table fs_table[];
 213 static struct ctl_table debug_table[];
 214 static struct ctl_table dev_table[];
 215 extern struct ctl_table random_table[];
 216 #ifdef CONFIG_EPOLL
 217 extern struct ctl_table epoll_table[];
 218 #endif
 219
 220 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 221 int sysctl_legacy_va_layout;
 222 #endif
 223
 224 /* The default sysctl tables: */
 225
 226 static struct ctl_table root_table[] = {
 227         {
 228                 .procname       = "kernel",
 229                 .mode           = 0555,
 230                 .child          = kern_table,
 231         },
 232         {
 233                 .procname       = "vm",
 234                 .mode           = 0555,
 235                 .child          = vm_table,
 236         },
 237         {
 238                 .procname       = "fs",
 239                 .mode           = 0555,
 240                 .child          = fs_table,
 241         },
 242         {
 243                 .procname       = "debug",
 244                 .mode           = 0555,
 245                 .child          = debug_table,
 246         },
 247         {
 248                 .procname       = "dev",
 249                 .mode           = 0555,
 250                 .child          = dev_table,
 251         },
 252         { }
 253 };
 254
 255 #ifdef CONFIG_SCHED_DEBUG
 256 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 257 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 258 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 259 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 260 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 261 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 262 #endif
 263
 264 #ifdef CONFIG_COMPACTION
 265 static int min_extfrag_threshold;
 266 static int max_extfrag_threshold = 1000;
 267 #endif
 268
 269 static struct ctl_table kern_table[] = {
 270         {
 271                 .procname       = "sched_child_runs_first",
 272                 .data           = &sysctl_sched_child_runs_first,
 273                 .maxlen         = sizeof(unsigned int),
 274                 .mode           = 0644,
 275                 .proc_handler   = proc_dointvec,
 276         },
 277 #ifdef CONFIG_SCHED_DEBUG
 278         {
 279                 .procname       = "sched_min_granularity_ns",
 280                 .data           = &sysctl_sched_min_granularity,
 281                 .maxlen         = sizeof(unsigned int),
 282                 .mode           = 0644,
 283                 .proc_handler   = sched_proc_update_handler,
 284                 .extra1         = &min_sched_granularity_ns,
 285                 .extra2         = &max_sched_granularity_ns,
 286         },
 287         {
 288                 .procname       = "sched_latency_ns",
 289                 .data           = &sysctl_sched_latency,
 290                 .maxlen         = sizeof(unsigned int),
 291                 .mode           = 0644,
 292                 .proc_handler   = sched_proc_update_handler,
 293                 .extra1         = &min_sched_granularity_ns,
 294                 .extra2         = &max_sched_granularity_ns,
 295         },
 296         {
 297                 .procname       = "sched_wakeup_granularity_ns",
 298                 .data           = &sysctl_sched_wakeup_granularity,
 299                 .maxlen         = sizeof(unsigned int),
 300                 .mode           = 0644,
 301                 .proc_handler   = sched_proc_update_handler,
 302                 .extra1         = &min_wakeup_granularity_ns,
 303                 .extra2         = &max_wakeup_granularity_ns,
 304         },
 305         {
 306                 .procname       = "sched_tunable_scaling",
 307                 .data           = &sysctl_sched_tunable_scaling,
 308                 .maxlen         = sizeof(enum sched_tunable_scaling),
 309                 .mode           = 0644,
 310                 .proc_handler   = sched_proc_update_handler,
 311                 .extra1         = &min_sched_tunable_scaling,
 312                 .extra2         = &max_sched_tunable_scaling,
 313         },
 314         {
 315                 .procname       = "sched_migration_cost",
 316                 .data           = &sysctl_sched_migration_cost,
 317                 .maxlen         = sizeof(unsigned int),
 318                 .mode           = 0644,
 319                 .proc_handler   = proc_dointvec,
 320         },
 321         {
 322                 .procname       = "sched_nr_migrate",
 323                 .data           = &sysctl_sched_nr_migrate,
 324                 .maxlen         = sizeof(unsigned int),
 325                 .mode           = 0644,
 326                 .proc_handler   = proc_dointvec,
 327         },
 328         {
 329                 .procname       = "sched_time_avg",
 330                 .data           = &sysctl_sched_time_avg,
 331                 .maxlen         = sizeof(unsigned int),
 332                 .mode           = 0644,
 333                 .proc_handler   = proc_dointvec,
 334         },
 335         {
 336                 .procname       = "sched_shares_window",
 337                 .data           = &sysctl_sched_shares_window,
 338                 .maxlen         = sizeof(unsigned int),
 339                 .mode           = 0644,
 340                 .proc_handler   = proc_dointvec,
 341         },
 342         {
 343                 .procname       = "timer_migration",
 344                 .data           = &sysctl_timer_migration,
 345                 .maxlen         = sizeof(unsigned int),
 346                 .mode           = 0644,
 347                 .proc_handler   = proc_dointvec_minmax,
 348                 .extra1         = &zero,
 349                 .extra2         = &one,
 350         },
 351 #endif
 352         {
 353                 .procname       = "sched_rt_period_us",
 354                 .data           = &sysctl_sched_rt_period,
 355                 .maxlen         = sizeof(unsigned int),
 356                 .mode           = 0644,
 357                 .proc_handler   = sched_rt_handler,
 358         },
 359         {
 360                 .procname       = "sched_rt_runtime_us",
 361                 .data           = &sysctl_sched_rt_runtime,
 362                 .maxlen         = sizeof(int),
 363                 .mode           = 0644,
 364                 .proc_handler   = sched_rt_handler,
 365         },
 366 #ifdef CONFIG_SCHED_AUTOGROUP
 367         {
 368                 .procname       = "sched_autogroup_enabled",
 369                 .data           = &sysctl_sched_autogroup_enabled,
 370                 .maxlen         = sizeof(unsigned int),
 371                 .mode           = 0644,
 372                 .proc_handler   = proc_dointvec_minmax,
 373                 .extra1         = &zero,
 374                 .extra2         = &one,
 375         },
 376 #endif
 377 #ifdef CONFIG_CFS_BANDWIDTH
 378         {
 379                 .procname       = "sched_cfs_bandwidth_slice_us",
 380                 .data           = &sysctl_sched_cfs_bandwidth_slice,
 381                 .maxlen         = sizeof(unsigned int),
 382                 .mode           = 0644,
 383                 .proc_handler   = proc_dointvec_minmax,
 384                 .extra1         = &one,
 385         },
 386 #endif
 387 #ifdef CONFIG_PROVE_LOCKING
 388         {
 389                 .procname       = "prove_locking",
 390                 .data           = &prove_locking,
 391                 .maxlen         = sizeof(int),
 392                 .mode           = 0644,
 393                 .proc_handler   = proc_dointvec,
 394         },
 395 #endif
 396 #ifdef CONFIG_LOCK_STAT
 397         {
 398                 .procname       = "lock_stat",
 399                 .data           = &lock_stat,
 400                 .maxlen         = sizeof(int),
 401                 .mode           = 0644,
 402                 .proc_handler   = proc_dointvec,
 403         },
 404 #endif
 405         {
 406                 .procname       = "panic",
 407                 .data           = &panic_timeout,
 408                 .maxlen         = sizeof(int),
 409                 .mode           = 0644,
 410                 .proc_handler   = proc_dointvec,
 411         },
 412         {
 413                 .procname       = "core_uses_pid",
 414                 .data           = &core_uses_pid,
 415                 .maxlen         = sizeof(int),
 416                 .mode           = 0644,
 417                 .proc_handler   = proc_dointvec,
 418         },
 419         {
 420                 .procname       = "core_pattern",
 421                 .data           = core_pattern,
 422                 .maxlen         = CORENAME_MAX_SIZE,
 423                 .mode           = 0644,
 424                 .proc_handler   = proc_dostring,
 425         },
 426         {
 427                 .procname       = "core_pipe_limit",
 428                 .data           = &core_pipe_limit,
 429                 .maxlen         = sizeof(unsigned int),
 430                 .mode           = 0644,
 431                 .proc_handler   = proc_dointvec,
 432         },
 433 #ifdef CONFIG_PROC_SYSCTL
 434         {
 435                 .procname       = "tainted",
 436                 .maxlen         = sizeof(long),
 437                 .mode           = 0644,
 438                 .proc_handler   = proc_taint,
 439         },
 440 #endif
 441 #ifdef CONFIG_LATENCYTOP
 442         {
 443                 .procname       = "latencytop",
 444                 .data           = &latencytop_enabled,
 445                 .maxlen         = sizeof(int),
 446                 .mode           = 0644,
 447                 .proc_handler   = proc_dointvec,
 448         },
 449 #endif
 450 #ifdef CONFIG_BLK_DEV_INITRD
 451         {
 452                 .procname       = "real-root-dev",
 453                 .data           = &real_root_dev,
 454                 .maxlen         = sizeof(int),
 455                 .mode           = 0644,
 456                 .proc_handler   = proc_dointvec,
 457         },
 458 #endif
 459         {
 460                 .procname       = "print-fatal-signals",
 461                 .data           = &print_fatal_signals,
 462                 .maxlen         = sizeof(int),
 463                 .mode           = 0644,
 464                 .proc_handler   = proc_dointvec,
 465         },
 466 #ifdef CONFIG_SPARC
 467         {
 468                 .procname       = "reboot-cmd",
 469                 .data           = reboot_command,
 470                 .maxlen         = 256,
 471                 .mode           = 0644,
 472                 .proc_handler   = proc_dostring,
 473         },
 474         {
 475                 .procname       = "stop-a",
 476                 .data           = &stop_a_enabled,
 477                 .maxlen         = sizeof (int),
 478                 .mode           = 0644,
 479                 .proc_handler   = proc_dointvec,
 480         },
 481         {
 482                 .procname       = "scons-poweroff",
 483                 .data           = &scons_pwroff,
 484                 .maxlen         = sizeof (int),
 485                 .mode           = 0644,
 486                 .proc_handler   = proc_dointvec,
 487         },
 488 #endif
 489 #ifdef CONFIG_SPARC64
 490         {
 491                 .procname       = "tsb-ratio",
 492                 .data           = &sysctl_tsb_ratio,
 493                 .maxlen         = sizeof (int),
 494                 .mode           = 0644,
 495                 .proc_handler   = proc_dointvec,
 496         },
 497 #endif
 498 #ifdef __hppa__
 499         {
 500                 .procname       = "soft-power",
 501                 .data           = &pwrsw_enabled,
 502                 .maxlen         = sizeof (int),
 503                 .mode           = 0644,
 504                 .proc_handler   = proc_dointvec,
 505         },
 506         {
 507                 .procname       = "unaligned-trap",
 508                 .data           = &unaligned_enabled,
 509                 .maxlen         = sizeof (int),
 510                 .mode           = 0644,
 511                 .proc_handler   = proc_dointvec,
 512         },
 513 #endif
 514         {
 515                 .procname       = "ctrl-alt-del",
 516                 .data           = &C_A_D,
 517                 .maxlen         = sizeof(int),
 518                 .mode           = 0644,
 519                 .proc_handler   = proc_dointvec,
 520         },
 521 #ifdef CONFIG_FUNCTION_TRACER
 522         {
 523                 .procname       = "ftrace_enabled",
 524                 .data           = &ftrace_enabled,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = ftrace_enable_sysctl,
 528         },
 529 #endif
 530 #ifdef CONFIG_STACK_TRACER
 531         {
 532                 .procname       = "stack_tracer_enabled",
 533                 .data           = &stack_tracer_enabled,
 534                 .maxlen         = sizeof(int),
 535                 .mode           = 0644,
 536                 .proc_handler   = stack_trace_sysctl,
 537         },
 538 #endif
 539 #ifdef CONFIG_TRACING
 540         {
 541                 .procname       = "ftrace_dump_on_oops",
 542                 .data           = &ftrace_dump_on_oops,
 543                 .maxlen         = sizeof(int),
 544                 .mode           = 0644,
 545                 .proc_handler   = proc_dointvec,
 546         },
 547 #endif
 548 #ifdef CONFIG_MODULES
 549         {
 550                 .procname       = "modprobe",
 551                 .data           = &modprobe_path,
 552                 .maxlen         = KMOD_PATH_LEN,
 553                 .mode           = 0644,
 554                 .proc_handler   = proc_dostring,
 555         },
 556         {
 557                 .procname       = "modules_disabled",
 558                 .data           = &modules_disabled,
 559                 .maxlen         = sizeof(int),
 560                 .mode           = 0644,
 561                 /* only handle a transition from default "0" to "1" */
 562                 .proc_handler   = proc_dointvec_minmax,
 563                 .extra1         = &one,
 564                 .extra2         = &one,
 565         },
 566 #endif
 567 #ifdef CONFIG_HOTPLUG
 568         {
 569                 .procname       = "hotplug",
 570                 .data           = &uevent_helper,
 571                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 572                 .mode           = 0644,
 573                 .proc_handler   = proc_dostring,
 574         },
 575 #endif
 576 #ifdef CONFIG_CHR_DEV_SG
 577         {
 578                 .procname       = "sg-big-buff",
 579                 .data           = &sg_big_buff,
 580                 .maxlen         = sizeof (int),
 581                 .mode           = 0444,
 582                 .proc_handler   = proc_dointvec,
 583         },
 584 #endif
 585 #ifdef CONFIG_BSD_PROCESS_ACCT
 586         {
 587                 .procname       = "acct",
 588                 .data           = &acct_parm,
 589                 .maxlen         = 3*sizeof(int),
 590                 .mode           = 0644,
 591                 .proc_handler   = proc_dointvec,
 592         },
 593 #endif
 594 #ifdef CONFIG_MAGIC_SYSRQ
 595         {
 596                 .procname       = "sysrq",
 597                 .data           = &__sysrq_enabled,
 598                 .maxlen         = sizeof (int),
 599                 .mode           = 0644,
 600                 .proc_handler   = sysrq_sysctl_handler,
 601         },
 602 #endif
 603 #ifdef CONFIG_PROC_SYSCTL
 604         {
 605                 .procname       = "cad_pid",
 606                 .data           = NULL,
 607                 .maxlen         = sizeof (int),
 608                 .mode           = 0600,
 609                 .proc_handler   = proc_do_cad_pid,
 610         },
 611 #endif
 612         {
 613                 .procname       = "threads-max",
 614                 .data           = &max_threads,
 615                 .maxlen         = sizeof(int),
 616                 .mode           = 0644,
 617                 .proc_handler   = proc_dointvec,
 618         },
 619         {
 620                 .procname       = "random",
 621                 .mode           = 0555,
 622                 .child          = random_table,
 623         },
 624         {
 625                 .procname       = "usermodehelper",
 626                 .mode           = 0555,
 627                 .child          = usermodehelper_table,
 628         },
 629         {
 630                 .procname       = "overflowuid",
 631                 .data           = &overflowuid,
 632                 .maxlen         = sizeof(int),
 633                 .mode           = 0644,
 634                 .proc_handler   = proc_dointvec_minmax,
 635                 .extra1         = &minolduid,
 636                 .extra2         = &maxolduid,
 637         },
 638         {
 639                 .procname       = "overflowgid",
 640                 .data           = &overflowgid,
 641                 .maxlen         = sizeof(int),
 642                 .mode           = 0644,
 643                 .proc_handler   = proc_dointvec_minmax,
 644                 .extra1         = &minolduid,
 645                 .extra2         = &maxolduid,
 646         },
 647 #ifdef CONFIG_S390
 648 #ifdef CONFIG_MATHEMU
 649         {
 650                 .procname       = "ieee_emulation_warnings",
 651                 .data           = &sysctl_ieee_emulation_warnings,
 652                 .maxlen         = sizeof(int),
 653                 .mode           = 0644,
 654                 .proc_handler   = proc_dointvec,
 655         },
 656 #endif
 657         {
 658                 .procname       = "userprocess_debug",
 659                 .data           = &show_unhandled_signals,
 660                 .maxlen         = sizeof(int),
 661                 .mode           = 0644,
 662                 .proc_handler   = proc_dointvec,
 663         },
 664 #endif
 665         {
 666                 .procname       = "pid_max",
 667                 .data           = &pid_max,
 668                 .maxlen         = sizeof (int),
 669                 .mode           = 0644,
 670                 .proc_handler   = proc_dointvec_minmax,
 671                 .extra1         = &pid_max_min,
 672                 .extra2         = &pid_max_max,
 673         },
 674         {
 675                 .procname       = "panic_on_oops",
 676                 .data           = &panic_on_oops,
 677                 .maxlen         = sizeof(int),
 678                 .mode           = 0644,
 679                 .proc_handler   = proc_dointvec,
 680         },
 681 #if defined CONFIG_PRINTK
 682         {
 683                 .procname       = "printk",
 684                 .data           = &console_loglevel,
 685                 .maxlen         = 4*sizeof(int),
 686                 .mode           = 0644,
 687                 .proc_handler   = proc_dointvec,
 688         },
 689         {
 690                 .procname       = "printk_ratelimit",
 691                 .data           = &printk_ratelimit_state.interval,
 692                 .maxlen         = sizeof(int),
 693                 .mode           = 0644,
 694                 .proc_handler   = proc_dointvec_jiffies,
 695         },
 696         {
 697                 .procname       = "printk_ratelimit_burst",
 698                 .data           = &printk_ratelimit_state.burst,
 699                 .maxlen         = sizeof(int),
 700                 .mode           = 0644,
 701                 .proc_handler   = proc_dointvec,
 702         },
 703         {
 704                 .procname       = "printk_delay",
 705                 .data           = &printk_delay_msec,
 706                 .maxlen         = sizeof(int),
 707                 .mode           = 0644,
 708                 .proc_handler   = proc_dointvec_minmax,
 709                 .extra1         = &zero,
 710                 .extra2         = &ten_thousand,
 711         },
 712         {
 713                 .procname       = "dmesg_restrict",
 714                 .data           = &dmesg_restrict,
 715                 .maxlen         = sizeof(int),
 716                 .mode           = 0644,
 717                 .proc_handler   = proc_dointvec_minmax,
 718                 .extra1         = &zero,
 719                 .extra2         = &one,
 720         },
 721         {
 722                 .procname       = "kptr_restrict",
 723                 .data           = &kptr_restrict,
 724                 .maxlen         = sizeof(int),
 725                 .mode           = 0644,
 726                 .proc_handler   = proc_dmesg_restrict,
 727                 .extra1         = &zero,
 728                 .extra2         = &two,
 729         },
 730 #endif
 731         {
 732                 .procname       = "ngroups_max",
 733                 .data           = &ngroups_max,
 734                 .maxlen         = sizeof (int),
 735                 .mode           = 0444,
 736                 .proc_handler   = proc_dointvec,
 737         },
 738         {
 739                 .procname       = "cap_last_cap",
 740                 .data           = (void *)&cap_last_cap,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0444,
 743                 .proc_handler   = proc_dointvec,
 744         },
 745 #if defined(CONFIG_LOCKUP_DETECTOR)
 746         {
 747                 .procname       = "watchdog",
 748                 .data           = &watchdog_enabled,
 749                 .maxlen         = sizeof (int),
 750                 .mode           = 0644,
 751                 .proc_handler   = proc_dowatchdog,
 752                 .extra1         = &zero,
 753                 .extra2         = &one,
 754         },
 755         {
 756                 .procname       = "watchdog_thresh",
 757                 .data           = &watchdog_thresh,
 758                 .maxlen         = sizeof(int),
 759                 .mode           = 0644,
 760                 .proc_handler   = proc_dowatchdog,
 761                 .extra1         = &neg_one,
 762                 .extra2         = &sixty,
 763         },
 764         {
 765                 .procname       = "softlockup_panic",
 766                 .data           = &softlockup_panic,
 767                 .maxlen         = sizeof(int),
 768                 .mode           = 0644,
 769                 .proc_handler   = proc_dointvec_minmax,
 770                 .extra1         = &zero,
 771                 .extra2         = &one,
 772         },
 773         {
 774                 .procname       = "nmi_watchdog",
 775                 .data           = &watchdog_enabled,
 776                 .maxlen         = sizeof (int),
 777                 .mode           = 0644,
 778                 .proc_handler   = proc_dowatchdog,
 779                 .extra1         = &zero,
 780                 .extra2         = &one,
 781         },
 782 #endif
 783 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 784         {
 785                 .procname       = "unknown_nmi_panic",
 786                 .data           = &unknown_nmi_panic,
 787                 .maxlen         = sizeof (int),
 788                 .mode           = 0644,
 789                 .proc_handler   = proc_dointvec,
 790         },
 791 #endif
 792 #if defined(CONFIG_X86)
 793         {
 794                 .procname       = "panic_on_unrecovered_nmi",
 795                 .data           = &panic_on_unrecovered_nmi,
 796                 .maxlen         = sizeof(int),
 797                 .mode           = 0644,
 798                 .proc_handler   = proc_dointvec,
 799         },
 800         {
 801                 .procname       = "panic_on_io_nmi",
 802                 .data           = &panic_on_io_nmi,
 803                 .maxlen         = sizeof(int),
 804                 .mode           = 0644,
 805                 .proc_handler   = proc_dointvec,
 806         },
 807 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 808         {
 809                 .procname       = "panic_on_stackoverflow",
 810                 .data           = &sysctl_panic_on_stackoverflow,
 811                 .maxlen         = sizeof(int),
 812                 .mode           = 0644,
 813                 .proc_handler   = proc_dointvec,
 814         },
 815 #endif
 816         {
 817                 .procname       = "bootloader_type",
 818                 .data           = &bootloader_type,
 819                 .maxlen         = sizeof (int),
 820                 .mode           = 0444,
 821                 .proc_handler   = proc_dointvec,
 822         },
 823         {
 824                 .procname       = "bootloader_version",
 825                 .data           = &bootloader_version,
 826                 .maxlen         = sizeof (int),
 827                 .mode           = 0444,
 828                 .proc_handler   = proc_dointvec,
 829         },
 830         {
 831                 .procname       = "kstack_depth_to_print",
 832                 .data           = &kstack_depth_to_print,
 833                 .maxlen         = sizeof(int),
 834                 .mode           = 0644,
 835                 .proc_handler   = proc_dointvec,
 836         },
 837         {
 838                 .procname       = "io_delay_type",
 839                 .data           = &io_delay_type,
 840                 .maxlen         = sizeof(int),
 841                 .mode           = 0644,
 842                 .proc_handler   = proc_dointvec,
 843         },
 844 #endif
 845 #if defined(CONFIG_MMU)
 846         {
 847                 .procname       = "randomize_va_space",
 848                 .data           = &randomize_va_space,
 849                 .maxlen         = sizeof(int),
 850                 .mode           = 0644,
 851                 .proc_handler   = proc_dointvec,
 852         },
 853 #endif
 854 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 855         {
 856                 .procname       = "spin_retry",
 857                 .data           = &spin_retry,
 858                 .maxlen         = sizeof (int),
 859                 .mode           = 0644,
 860                 .proc_handler   = proc_dointvec,
 861         },
 862 #endif
 863 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 864         {
 865                 .procname       = "acpi_video_flags",
 866                 .data           = &acpi_realmode_flags,
 867                 .maxlen         = sizeof (unsigned long),
 868                 .mode           = 0644,
 869                 .proc_handler   = proc_doulongvec_minmax,
 870         },
 871 #endif
 872 #ifdef CONFIG_IA64
 873         {
 874                 .procname       = "ignore-unaligned-usertrap",
 875                 .data           = &no_unaligned_warning,
 876                 .maxlen         = sizeof (int),
 877                 .mode           = 0644,
 878                 .proc_handler   = proc_dointvec,
 879         },
 880         {
 881                 .procname       = "unaligned-dump-stack",
 882                 .data           = &unaligned_dump_stack,
 883                 .maxlen         = sizeof (int),
 884                 .mode           = 0644,
 885                 .proc_handler   = proc_dointvec,
 886         },
 887 #endif
 888 #ifdef CONFIG_DETECT_HUNG_TASK
 889         {
 890                 .procname       = "hung_task_panic",
 891                 .data           = &sysctl_hung_task_panic,
 892                 .maxlen         = sizeof(int),
 893                 .mode           = 0644,
 894                 .proc_handler   = proc_dointvec_minmax,
 895                 .extra1         = &zero,
 896                 .extra2         = &one,
 897         },
 898         {
 899                 .procname       = "hung_task_check_count",
 900                 .data           = &sysctl_hung_task_check_count,
 901                 .maxlen         = sizeof(unsigned long),
 902                 .mode           = 0644,
 903                 .proc_handler   = proc_doulongvec_minmax,
 904         },
 905         {
 906                 .procname       = "hung_task_timeout_secs",
 907                 .data           = &sysctl_hung_task_timeout_secs,
 908                 .maxlen         = sizeof(unsigned long),
 909                 .mode           = 0644,
 910                 .proc_handler   = proc_dohung_task_timeout_secs,
 911         },
 912         {
 913                 .procname       = "hung_task_warnings",
 914                 .data           = &sysctl_hung_task_warnings,
 915                 .maxlen         = sizeof(unsigned long),
 916                 .mode           = 0644,
 917                 .proc_handler   = proc_doulongvec_minmax,
 918         },
 919 #endif
 920 #ifdef CONFIG_COMPAT
 921         {
 922                 .procname       = "compat-log",
 923                 .data           = &compat_log,
 924                 .maxlen         = sizeof (int),
 925                 .mode           = 0644,
 926                 .proc_handler   = proc_dointvec,
 927         },
 928 #endif
 929 #ifdef CONFIG_RT_MUTEXES
 930         {
 931                 .procname       = "max_lock_depth",
 932                 .data           = &max_lock_depth,
 933                 .maxlen         = sizeof(int),
 934                 .mode           = 0644,
 935                 .proc_handler   = proc_dointvec,
 936         },
 937 #endif
 938         {
 939                 .procname       = "poweroff_cmd",
 940                 .data           = &poweroff_cmd,
 941                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 942                 .mode           = 0644,
 943                 .proc_handler   = proc_dostring,
 944         },
 945 #ifdef CONFIG_KEYS
 946         {
 947                 .procname       = "keys",
 948                 .mode           = 0555,
 949                 .child          = key_sysctls,
 950         },
 951 #endif
 952 #ifdef CONFIG_RCU_TORTURE_TEST
 953         {
 954                 .procname       = "rcutorture_runnable",
 955                 .data           = &rcutorture_runnable,
 956                 .maxlen         = sizeof(int),
 957                 .mode           = 0644,
 958                 .proc_handler   = proc_dointvec,
 959         },
 960 #endif
 961 #ifdef CONFIG_PERF_EVENTS
 962         /*
 963          * User-space scripts rely on the existence of this file
 964          * as a feature check for perf_events being enabled.
 965          *
 966          * So it's an ABI, do not remove!
 967          */
 968         {
 969                 .procname       = "perf_event_paranoid",
 970                 .data           = &sysctl_perf_event_paranoid,
 971                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 972                 .mode           = 0644,
 973                 .proc_handler   = proc_dointvec,
 974         },
 975         {
 976                 .procname       = "perf_event_mlock_kb",
 977                 .data           = &sysctl_perf_event_mlock,
 978                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 979                 .mode           = 0644,
 980                 .proc_handler   = proc_dointvec,
 981         },
 982         {
 983                 .procname       = "perf_event_max_sample_rate",
 984                 .data           = &sysctl_perf_event_sample_rate,
 985                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 986                 .mode           = 0644,
 987                 .proc_handler   = perf_proc_update_handler,
 988         },
 989 #endif
 990 #ifdef CONFIG_KMEMCHECK
 991         {
 992                 .procname       = "kmemcheck",
 993                 .data           = &kmemcheck_enabled,
 994                 .maxlen         = sizeof(int),
 995                 .mode           = 0644,
 996                 .proc_handler   = proc_dointvec,
 997         },
 998 #endif
 999 #ifdef CONFIG_BLOCK
1000         {
1001                 .procname       = "blk_iopoll",
1002                 .data           = &blk_iopoll_enabled,
1003                 .maxlen         = sizeof(int),
1004                 .mode           = 0644,
1005                 .proc_handler   = proc_dointvec,
1006         },
1007 #endif
1008         { }
1009 };
1010
1011 static struct ctl_table vm_table[] = {
1012         {
1013                 .procname       = "overcommit_memory",
1014                 .data           = &sysctl_overcommit_memory,
1015                 .maxlen         = sizeof(sysctl_overcommit_memory),
1016                 .mode           = 0644,
1017                 .proc_handler   = proc_dointvec_minmax,
1018                 .extra1         = &zero,
1019                 .extra2         = &two,
1020         },
1021         {
1022                 .procname       = "panic_on_oom",
1023                 .data           = &sysctl_panic_on_oom,
1024                 .maxlen         = sizeof(sysctl_panic_on_oom),
1025                 .mode           = 0644,
1026                 .proc_handler   = proc_dointvec_minmax,
1027                 .extra1         = &zero,
1028                 .extra2         = &two,
1029         },
1030         {
1031                 .procname       = "oom_kill_allocating_task",
1032                 .data           = &sysctl_oom_kill_allocating_task,
1033                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1034                 .mode           = 0644,
1035                 .proc_handler   = proc_dointvec,
1036         },
1037         {
1038                 .procname       = "oom_dump_tasks",
1039                 .data           = &sysctl_oom_dump_tasks,
1040                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1041                 .mode           = 0644,
1042                 .proc_handler   = proc_dointvec,
1043         },
1044         {
1045                 .procname       = "overcommit_ratio",
1046                 .data           = &sysctl_overcommit_ratio,
1047                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1048                 .mode           = 0644,
1049                 .proc_handler   = proc_dointvec,
1050         },
1051         {
1052                 .procname       = "page-cluster",
1053                 .data           = &page_cluster,
1054                 .maxlen         = sizeof(int),
1055                 .mode           = 0644,
1056                 .proc_handler   = proc_dointvec_minmax,
1057                 .extra1         = &zero,
1058         },
1059         {
1060                 .procname       = "dirty_background_ratio",
1061                 .data           = &dirty_background_ratio,
1062                 .maxlen         = sizeof(dirty_background_ratio),
1063                 .mode           = 0644,
1064                 .proc_handler   = dirty_background_ratio_handler,
1065                 .extra1         = &zero,
1066                 .extra2         = &one_hundred,
1067         },
1068         {
1069                 .procname       = "dirty_background_bytes",
1070                 .data           = &dirty_background_bytes,
1071                 .maxlen         = sizeof(dirty_background_bytes),
1072                 .mode           = 0644,
1073                 .proc_handler   = dirty_background_bytes_handler,
1074                 .extra1         = &one_ul,
1075         },
1076         {
1077                 .procname       = "dirty_ratio",
1078                 .data           = &vm_dirty_ratio,
1079                 .maxlen         = sizeof(vm_dirty_ratio),
1080                 .mode           = 0644,
1081                 .proc_handler   = dirty_ratio_handler,
1082                 .extra1         = &zero,
1083                 .extra2         = &one_hundred,
1084         },
1085         {
1086                 .procname       = "dirty_bytes",
1087                 .data           = &vm_dirty_bytes,
1088                 .maxlen         = sizeof(vm_dirty_bytes),
1089                 .mode           = 0644,
1090                 .proc_handler   = dirty_bytes_handler,
1091                 .extra1         = &dirty_bytes_min,
1092         },
1093         {
1094                 .procname       = "dirty_writeback_centisecs",
1095                 .data           = &dirty_writeback_interval,
1096                 .maxlen         = sizeof(dirty_writeback_interval),
1097                 .mode           = 0644,
1098                 .proc_handler   = dirty_writeback_centisecs_handler,
1099         },
1100         {
1101                 .procname       = "dirty_expire_centisecs",
1102                 .data           = &dirty_expire_interval,
1103                 .maxlen         = sizeof(dirty_expire_interval),
1104                 .mode           = 0644,
1105                 .proc_handler   = proc_dointvec_minmax,
1106                 .extra1         = &zero,
1107         },
1108         {
1109                 .procname       = "nr_pdflush_threads",
1110                 .data           = &nr_pdflush_threads,
1111                 .maxlen         = sizeof nr_pdflush_threads,
1112                 .mode           = 0444 /* read-only*/,
1113                 .proc_handler   = proc_dointvec,
1114         },
1115         {
1116                 .procname       = "swappiness",
1117                 .data           = &vm_swappiness,
1118                 .maxlen         = sizeof(vm_swappiness),
1119                 .mode           = 0644,
1120                 .proc_handler   = proc_dointvec_minmax,
1121                 .extra1         = &zero,
1122                 .extra2         = &one_hundred,
1123         },
1124 #ifdef CONFIG_HUGETLB_PAGE
1125         {
1126                 .procname       = "nr_hugepages",
1127                 .data           = NULL,
1128                 .maxlen         = sizeof(unsigned long),
1129                 .mode           = 0644,
1130                 .proc_handler   = hugetlb_sysctl_handler,
1131                 .extra1         = (void *)&hugetlb_zero,
1132                 .extra2         = (void *)&hugetlb_infinity,
1133         },
1134 #ifdef CONFIG_NUMA
1135         {
1136                 .procname       = "nr_hugepages_mempolicy",
1137                 .data           = NULL,
1138                 .maxlen         = sizeof(unsigned long),
1139                 .mode           = 0644,
1140                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1141                 .extra1         = (void *)&hugetlb_zero,
1142                 .extra2         = (void *)&hugetlb_infinity,
1143         },
1144 #endif
1145          {
1146                 .procname       = "hugetlb_shm_group",
1147                 .data           = &sysctl_hugetlb_shm_group,
1148                 .maxlen         = sizeof(gid_t),
1149                 .mode           = 0644,
1150                 .proc_handler   = proc_dointvec,
1151          },
1152          {
1153                 .procname       = "hugepages_treat_as_movable",
1154                 .data           = &hugepages_treat_as_movable,
1155                 .maxlen         = sizeof(int),
1156                 .mode           = 0644,
1157                 .proc_handler   = hugetlb_treat_movable_handler,
1158         },
1159         {
1160                 .procname       = "nr_overcommit_hugepages",
1161                 .data           = NULL,
1162                 .maxlen         = sizeof(unsigned long),
1163                 .mode           = 0644,
1164                 .proc_handler   = hugetlb_overcommit_handler,
1165                 .extra1         = (void *)&hugetlb_zero,
1166                 .extra2         = (void *)&hugetlb_infinity,
1167         },
1168 #endif
1169         {
1170                 .procname       = "lowmem_reserve_ratio",
1171                 .data           = &sysctl_lowmem_reserve_ratio,
1172                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1173                 .mode           = 0644,
1174                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1175         },
1176         {
1177                 .procname       = "drop_caches",
1178                 .data           = &sysctl_drop_caches,
1179                 .maxlen         = sizeof(int),
1180                 .mode           = 0644,
1181                 .proc_handler   = drop_caches_sysctl_handler,
1182                 .extra1         = &one,
1183                 .extra2         = &three,
1184         },
1185 #ifdef CONFIG_COMPACTION
1186         {
1187                 .procname       = "compact_memory",
1188                 .data           = &sysctl_compact_memory,
1189                 .maxlen         = sizeof(int),
1190                 .mode           = 0200,
1191                 .proc_handler   = sysctl_compaction_handler,
1192         },
1193         {
1194                 .procname       = "extfrag_threshold",
1195                 .data           = &sysctl_extfrag_threshold,
1196                 .maxlen         = sizeof(int),
1197                 .mode           = 0644,
1198                 .proc_handler   = sysctl_extfrag_handler,
1199                 .extra1         = &min_extfrag_threshold,
1200                 .extra2         = &max_extfrag_threshold,
1201         },
1202
1203 #endif /* CONFIG_COMPACTION */
1204         {
1205                 .procname       = "min_free_kbytes",
1206                 .data           = &min_free_kbytes,
1207                 .maxlen         = sizeof(min_free_kbytes),
1208                 .mode           = 0644,
1209                 .proc_handler   = min_free_kbytes_sysctl_handler,
1210                 .extra1         = &zero,
1211         },
1212         {
1213                 .procname       = "percpu_pagelist_fraction",
1214                 .data           = &percpu_pagelist_fraction,
1215                 .maxlen         = sizeof(percpu_pagelist_fraction),
1216                 .mode           = 0644,
1217                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1218                 .extra1         = &min_percpu_pagelist_fract,
1219         },
1220 #ifdef CONFIG_MMU
1221         {
1222                 .procname       = "max_map_count",
1223                 .data           = &sysctl_max_map_count,
1224                 .maxlen         = sizeof(sysctl_max_map_count),
1225                 .mode           = 0644,
1226                 .proc_handler   = proc_dointvec_minmax,
1227                 .extra1         = &zero,
1228         },
1229 #else
1230         {
1231                 .procname       = "nr_trim_pages",
1232                 .data           = &sysctl_nr_trim_pages,
1233                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1234                 .mode           = 0644,
1235                 .proc_handler   = proc_dointvec_minmax,
1236                 .extra1         = &zero,
1237         },
1238 #endif
1239         {
1240                 .procname       = "laptop_mode",
1241                 .data           = &laptop_mode,
1242                 .maxlen         = sizeof(laptop_mode),
1243                 .mode           = 0644,
1244                 .proc_handler   = proc_dointvec_jiffies,
1245         },
1246         {
1247                 .procname       = "block_dump",
1248                 .data           = &block_dump,
1249                 .maxlen         = sizeof(block_dump),
1250                 .mode           = 0644,
1251                 .proc_handler   = proc_dointvec,
1252                 .extra1         = &zero,
1253         },
1254         {
1255                 .procname       = "vfs_cache_pressure",
1256                 .data           = &sysctl_vfs_cache_pressure,
1257                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1258                 .mode           = 0644,
1259                 .proc_handler   = proc_dointvec,
1260                 .extra1         = &zero,
1261         },
1262 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1263         {
1264                 .procname       = "legacy_va_layout",
1265                 .data           = &sysctl_legacy_va_layout,
1266                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1267                 .mode           = 0644,
1268                 .proc_handler   = proc_dointvec,
1269                 .extra1         = &zero,
1270         },
1271 #endif
1272 #ifdef CONFIG_NUMA
1273         {
1274                 .procname       = "zone_reclaim_mode",
1275                 .data           = &zone_reclaim_mode,
1276                 .maxlen         = sizeof(zone_reclaim_mode),
1277                 .mode           = 0644,
1278                 .proc_handler   = proc_dointvec,
1279                 .extra1         = &zero,
1280         },
1281         {
1282                 .procname       = "min_unmapped_ratio",
1283                 .data           = &sysctl_min_unmapped_ratio,
1284                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1285                 .mode           = 0644,
1286                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1287                 .extra1         = &zero,
1288                 .extra2         = &one_hundred,
1289         },
1290         {
1291                 .procname       = "min_slab_ratio",
1292                 .data           = &sysctl_min_slab_ratio,
1293                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1294                 .mode           = 0644,
1295                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1296                 .extra1         = &zero,
1297                 .extra2         = &one_hundred,
1298         },
1299 #endif
1300 #ifdef CONFIG_SMP
1301         {
1302                 .procname       = "stat_interval",
1303                 .data           = &sysctl_stat_interval,
1304                 .maxlen         = sizeof(sysctl_stat_interval),
1305                 .mode           = 0644,
1306                 .proc_handler   = proc_dointvec_jiffies,
1307         },
1308 #endif
1309 #ifdef CONFIG_MMU
1310         {
1311                 .procname       = "mmap_min_addr",
1312                 .data           = &dac_mmap_min_addr,
1313                 .maxlen         = sizeof(unsigned long),
1314                 .mode           = 0644,
1315                 .proc_handler   = mmap_min_addr_handler,
1316         },
1317 #endif
1318 #ifdef CONFIG_NUMA
1319         {
1320                 .procname       = "numa_zonelist_order",
1321                 .data           = &numa_zonelist_order,
1322                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1323                 .mode           = 0644,
1324                 .proc_handler   = numa_zonelist_order_handler,
1325         },
1326 #endif
1327 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1328    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1329         {
1330                 .procname       = "vdso_enabled",
1331                 .data           = &vdso_enabled,
1332                 .maxlen         = sizeof(vdso_enabled),
1333                 .mode           = 0644,
1334                 .proc_handler   = proc_dointvec,
1335                 .extra1         = &zero,
1336         },
1337 #endif
1338 #ifdef CONFIG_HIGHMEM
1339         {
1340                 .procname       = "highmem_is_dirtyable",
1341                 .data           = &vm_highmem_is_dirtyable,
1342                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1343                 .mode           = 0644,
1344                 .proc_handler   = proc_dointvec_minmax,
1345                 .extra1         = &zero,
1346                 .extra2         = &one,
1347         },
1348 #endif
1349         {
1350                 .procname       = "scan_unevictable_pages",
1351                 .data           = &scan_unevictable_pages,
1352                 .maxlen         = sizeof(scan_unevictable_pages),
1353                 .mode           = 0644,
1354                 .proc_handler   = scan_unevictable_handler,
1355         },
1356 #ifdef CONFIG_MEMORY_FAILURE
1357         {
1358                 .procname       = "memory_failure_early_kill",
1359                 .data           = &sysctl_memory_failure_early_kill,
1360                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1361                 .mode           = 0644,
1362                 .proc_handler   = proc_dointvec_minmax,
1363                 .extra1         = &zero,
1364                 .extra2         = &one,
1365         },
1366         {
1367                 .procname       = "memory_failure_recovery",
1368                 .data           = &sysctl_memory_failure_recovery,
1369                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1370                 .mode           = 0644,
1371                 .proc_handler   = proc_dointvec_minmax,
1372                 .extra1         = &zero,
1373                 .extra2         = &one,
1374         },
1375 #endif
1376         { }
1377 };
1378
1379 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1380 static struct ctl_table binfmt_misc_table[] = {
1381         { }
1382 };
1383 #endif
1384
1385 static struct ctl_table fs_table[] = {
1386         {
1387                 .procname       = "inode-nr",
1388                 .data           = &inodes_stat,
1389                 .maxlen         = 2*sizeof(int),
1390                 .mode           = 0444,
1391                 .proc_handler   = proc_nr_inodes,
1392         },
1393         {
1394                 .procname       = "inode-state",
1395                 .data           = &inodes_stat,
1396                 .maxlen         = 7*sizeof(int),
1397                 .mode           = 0444,
1398                 .proc_handler   = proc_nr_inodes,
1399         },
1400         {
1401                 .procname       = "file-nr",
1402                 .data           = &files_stat,
1403                 .maxlen         = sizeof(files_stat),
1404                 .mode           = 0444,
1405                 .proc_handler   = proc_nr_files,
1406         },
1407         {
1408                 .procname       = "file-max",
1409                 .data           = &files_stat.max_files,
1410                 .maxlen         = sizeof(files_stat.max_files),
1411                 .mode           = 0644,
1412                 .proc_handler   = proc_doulongvec_minmax,
1413         },
1414         {
1415                 .procname       = "nr_open",
1416                 .data           = &sysctl_nr_open,
1417                 .maxlen         = sizeof(int),
1418                 .mode           = 0644,
1419                 .proc_handler   = proc_dointvec_minmax,
1420                 .extra1         = &sysctl_nr_open_min,
1421                 .extra2         = &sysctl_nr_open_max,
1422         },
1423         {
1424                 .procname       = "dentry-state",
1425                 .data           = &dentry_stat,
1426                 .maxlen         = 6*sizeof(int),
1427                 .mode           = 0444,
1428                 .proc_handler   = proc_nr_dentry,
1429         },
1430         {
1431                 .procname       = "overflowuid",
1432                 .data           = &fs_overflowuid,
1433                 .maxlen         = sizeof(int),
1434                 .mode           = 0644,
1435                 .proc_handler   = proc_dointvec_minmax,
1436                 .extra1         = &minolduid,
1437                 .extra2         = &maxolduid,
1438         },
1439         {
1440                 .procname       = "overflowgid",
1441                 .data           = &fs_overflowgid,
1442                 .maxlen         = sizeof(int),
1443                 .mode           = 0644,
1444                 .proc_handler   = proc_dointvec_minmax,
1445                 .extra1         = &minolduid,
1446                 .extra2         = &maxolduid,
1447         },
1448 #ifdef CONFIG_FILE_LOCKING
1449         {
1450                 .procname       = "leases-enable",
1451                 .data           = &leases_enable,
1452                 .maxlen         = sizeof(int),
1453                 .mode           = 0644,
1454                 .proc_handler   = proc_dointvec,
1455         },
1456 #endif
1457 #ifdef CONFIG_DNOTIFY
1458         {
1459                 .procname       = "dir-notify-enable",
1460                 .data           = &dir_notify_enable,
1461                 .maxlen         = sizeof(int),
1462                 .mode           = 0644,
1463                 .proc_handler   = proc_dointvec,
1464         },
1465 #endif
1466 #ifdef CONFIG_MMU
1467 #ifdef CONFIG_FILE_LOCKING
1468         {
1469                 .procname       = "lease-break-time",
1470                 .data           = &lease_break_time,
1471                 .maxlen         = sizeof(int),
1472                 .mode           = 0644,
1473                 .proc_handler   = proc_dointvec,
1474         },
1475 #endif
1476 #ifdef CONFIG_AIO
1477         {
1478                 .procname       = "aio-nr",
1479                 .data           = &aio_nr,
1480                 .maxlen         = sizeof(aio_nr),
1481                 .mode           = 0444,
1482                 .proc_handler   = proc_doulongvec_minmax,
1483         },
1484         {
1485                 .procname       = "aio-max-nr",
1486                 .data           = &aio_max_nr,
1487                 .maxlen         = sizeof(aio_max_nr),
1488                 .mode           = 0644,
1489                 .proc_handler   = proc_doulongvec_minmax,
1490         },
1491 #endif /* CONFIG_AIO */
1492 #ifdef CONFIG_INOTIFY_USER
1493         {
1494                 .procname       = "inotify",
1495                 .mode           = 0555,
1496                 .child          = inotify_table,
1497         },
1498 #endif
1499 #ifdef CONFIG_EPOLL
1500         {
1501                 .procname       = "epoll",
1502                 .mode           = 0555,
1503                 .child          = epoll_table,
1504         },
1505 #endif
1506 #endif
1507         {
1508                 .procname       = "suid_dumpable",
1509                 .data           = &suid_dumpable,
1510                 .maxlen         = sizeof(int),
1511                 .mode           = 0644,
1512                 .proc_handler   = proc_dointvec_minmax,
1513                 .extra1         = &zero,
1514                 .extra2         = &two,
1515         },
1516 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1517         {
1518                 .procname       = "binfmt_misc",
1519                 .mode           = 0555,
1520                 .child          = binfmt_misc_table,
1521         },
1522 #endif
1523         {
1524                 .procname       = "pipe-max-size",
1525                 .data           = &pipe_max_size,
1526                 .maxlen         = sizeof(int),
1527                 .mode           = 0644,
1528                 .proc_handler   = &pipe_proc_fn,
1529                 .extra1         = &pipe_min_size,
1530         },
1531         { }
1532 };
1533
1534 static struct ctl_table debug_table[] = {
1535 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1536     defined(CONFIG_S390) || defined(CONFIG_TILE)
1537         {
1538                 .procname       = "exception-trace",
1539                 .data           = &show_unhandled_signals,
1540                 .maxlen         = sizeof(int),
1541                 .mode           = 0644,
1542                 .proc_handler   = proc_dointvec
1543         },
1544 #endif
1545 #if defined(CONFIG_OPTPROBES)
1546         {
1547                 .procname       = "kprobes-optimization",
1548                 .data           = &sysctl_kprobes_optimization,
1549                 .maxlen         = sizeof(int),
1550                 .mode           = 0644,
1551                 .proc_handler   = proc_kprobes_optimization_handler,
1552                 .extra1         = &zero,
1553                 .extra2         = &one,
1554         },
1555 #endif
1556         { }
1557 };
1558
1559 static struct ctl_table dev_table[] = {
1560         { }
1561 };
1562
1563 static DEFINE_SPINLOCK(sysctl_lock);
1564
1565 /* called under sysctl_lock */
1566 static int use_table(struct ctl_table_header *p)
1567 {
1568         if (unlikely(p->unregistering))
1569                 return 0;
1570         p->used++;
1571         return 1;
1572 }
1573
1574 /* called under sysctl_lock */
1575 static void unuse_table(struct ctl_table_header *p)
1576 {
1577         if (!--p->used)
1578                 if (unlikely(p->unregistering))
1579                         complete(p->unregistering);
1580 }
1581
1582 /* called under sysctl_lock, will reacquire if has to wait */
1583 static void start_unregistering(struct ctl_table_header *p)
1584 {
1585         /*
1586          * if p->used is 0, nobody will ever touch that entry again;
1587          * we'll eliminate all paths to it before dropping sysctl_lock
1588          */
1589         if (unlikely(p->used)) {
1590                 struct completion wait;
1591                 init_completion(&wait);
1592                 p->unregistering = &wait;
1593                 spin_unlock(&sysctl_lock);
1594                 wait_for_completion(&wait);
1595                 spin_lock(&sysctl_lock);
1596         } else {
1597                 /* anything non-NULL; we'll never dereference it */
1598                 p->unregistering = ERR_PTR(-EINVAL);
1599         }
1600         /*
1601          * do not remove from the list until nobody holds it; walking the
1602          * list in do_sysctl() relies on that.
1603          */
1604         list_del_init(&p->ctl_entry);
1605 }
1606
1607 void sysctl_head_get(struct ctl_table_header *head)
1608 {
1609         spin_lock(&sysctl_lock);
1610         head->count++;
1611         spin_unlock(&sysctl_lock);
1612 }
1613
1614 void sysctl_head_put(struct ctl_table_header *head)
1615 {
1616         spin_lock(&sysctl_lock);
1617         if (!--head->count)
1618                 kfree_rcu(head, rcu);
1619         spin_unlock(&sysctl_lock);
1620 }
1621
1622 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1623 {
1624         if (!head)
1625                 BUG();
1626         spin_lock(&sysctl_lock);
1627         if (!use_table(head))
1628                 head = ERR_PTR(-ENOENT);
1629         spin_unlock(&sysctl_lock);
1630         return head;
1631 }
1632
1633 void sysctl_head_finish(struct ctl_table_header *head)
1634 {
1635         if (!head)
1636                 return;
1637         spin_lock(&sysctl_lock);
1638         unuse_table(head);
1639         spin_unlock(&sysctl_lock);
1640 }
1641
1642 static struct ctl_table_set *
1643 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1644 {
1645         struct ctl_table_set *set = &root->default_set;
1646         if (root->lookup)
1647                 set = root->lookup(root, namespaces);
1648         return set;
1649 }
1650
1651 static struct list_head *
1652 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1653 {
1654         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1655         return &set->list;
1656 }
1657
1658 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1659                                             struct ctl_table_header *prev)
1660 {
1661         struct ctl_table_root *root;
1662         struct list_head *header_list;
1663         struct ctl_table_header *head;
1664         struct list_head *tmp;
1665
1666         spin_lock(&sysctl_lock);
1667         if (prev) {
1668                 head = prev;
1669                 tmp = &prev->ctl_entry;
1670                 unuse_table(prev);
1671                 goto next;
1672         }
1673         tmp = &root_table_header.ctl_entry;
1674         for (;;) {
1675                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1676
1677                 if (!use_table(head))
1678                         goto next;
1679                 spin_unlock(&sysctl_lock);
1680                 return head;
1681         next:
1682                 root = head->root;
1683                 tmp = tmp->next;
1684                 header_list = lookup_header_list(root, namespaces);
1685                 if (tmp != header_list)
1686                         continue;
1687
1688                 do {
1689                         root = list_entry(root->root_list.next,
1690                                         struct ctl_table_root, root_list);
1691                         if (root == &sysctl_table_root)
1692                                 goto out;
1693                         header_list = lookup_header_list(root, namespaces);
1694                 } while (list_empty(header_list));
1695                 tmp = header_list->next;
1696         }
1697 out:
1698         spin_unlock(&sysctl_lock);
1699         return NULL;
1700 }
1701
1702 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1703 {
1704         return __sysctl_head_next(current->nsproxy, prev);
1705 }
1706
1707 void register_sysctl_root(struct ctl_table_root *root)
1708 {
1709         spin_lock(&sysctl_lock);
1710         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1711         spin_unlock(&sysctl_lock);
1712 }
1713
1714 /*
1715  * sysctl_perm does NOT grant the superuser all rights automatically, because
1716  * some sysctl variables are readonly even to root.
1717  */
1718
1719 static int test_perm(int mode, int op)
1720 {
1721         if (!current_euid())
1722                 mode >>= 6;
1723         else if (in_egroup_p(0))
1724                 mode >>= 3;
1725         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1726                 return 0;
1727         return -EACCES;
1728 }
1729
1730 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1731 {
1732         int mode;
1733
1734         if (root->permissions)
1735                 mode = root->permissions(root, current->nsproxy, table);
1736         else
1737                 mode = table->mode;
1738
1739         return test_perm(mode, op);
1740 }
1741
1742 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1743 {
1744         for (; table->procname; table++) {
1745                 table->parent = parent;
1746                 if (table->child)
1747                         sysctl_set_parent(table, table->child);
1748         }
1749 }
1750
1751 static __init int sysctl_init(void)
1752 {
1753         sysctl_set_parent(NULL, root_table);
1754 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1755         sysctl_check_table(current->nsproxy, root_table);
1756 #endif
1757         return 0;
1758 }
1759
1760 core_initcall(sysctl_init);
1761
1762 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1763                                       struct ctl_table *table)
1764 {
1765         struct ctl_table *p;
1766         const char *s = branch->procname;
1767
1768         /* branch should have named subdirectory as its first element */
1769         if (!s || !branch->child)
1770                 return NULL;
1771
1772         /* ... and nothing else */
1773         if (branch[1].procname)
1774                 return NULL;
1775
1776         /* table should contain subdirectory with the same name */
1777         for (p = table; p->procname; p++) {
1778                 if (!p->child)
1779                         continue;
1780                 if (p->procname && strcmp(p->procname, s) == 0)
1781                         return p;
1782         }
1783         return NULL;
1784 }
1785
1786 /* see if attaching q to p would be an improvement */
1787 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1788 {
1789         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1790         struct ctl_table *next;
1791         int is_better = 0;
1792         int not_in_parent = !p->attached_by;
1793
1794         while ((next = is_branch_in(by, to)) != NULL) {
1795                 if (by == q->attached_by)
1796                         is_better = 1;
1797                 if (to == p->attached_by)
1798                         not_in_parent = 1;
1799                 by = by->child;
1800                 to = next->child;
1801         }
1802
1803         if (is_better && not_in_parent) {
1804                 q->attached_by = by;
1805                 q->attached_to = to;
1806                 q->parent = p;
1807         }
1808 }
1809
1810 /**
1811  * __register_sysctl_paths - register a sysctl hierarchy
1812  * @root: List of sysctl headers to register on
1813  * @namespaces: Data to compute which lists of sysctl entries are visible
1814  * @path: The path to the directory the sysctl table is in.
1815  * @table: the top-level table structure
1816  *
1817  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1818  * array. A completely 0 filled entry terminates the table.
1819  *
1820  * The members of the &struct ctl_table structure are used as follows:
1821  *
1822  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1823  *            enter a sysctl file
1824  *
1825  * data - a pointer to data for use by proc_handler
1826  *
1827  * maxlen - the maximum size in bytes of the data
1828  *
1829  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1830  *
1831  * child - a pointer to the child sysctl table if this entry is a directory, or
1832  *         %NULL.
1833  *
1834  * proc_handler - the text handler routine (described below)
1835  *
1836  * de - for internal use by the sysctl routines
1837  *
1838  * extra1, extra2 - extra pointers usable by the proc handler routines
1839  *
1840  * Leaf nodes in the sysctl tree will be represented by a single file
1841  * under /proc; non-leaf nodes will be represented by directories.
1842  *
1843  * sysctl(2) can automatically manage read and write requests through
1844  * the sysctl table.  The data and maxlen fields of the ctl_table
1845  * struct enable minimal validation of the values being written to be
1846  * performed, and the mode field allows minimal authentication.
1847  *
1848  * There must be a proc_handler routine for any terminal nodes
1849  * mirrored under /proc/sys (non-terminals are handled by a built-in
1850  * directory handler).  Several default handlers are available to
1851  * cover common cases -
1852  *
1853  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1854  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1855  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1856  *
1857  * It is the handler's job to read the input buffer from user memory
1858  * and process it. The handler should return 0 on success.
1859  *
1860  * This routine returns %NULL on a failure to register, and a pointer
1861  * to the table header on success.
1862  */
1863 struct ctl_table_header *__register_sysctl_paths(
1864         struct ctl_table_root *root,
1865         struct nsproxy *namespaces,
1866         const struct ctl_path *path, struct ctl_table *table)
1867 {
1868         struct ctl_table_header *header;
1869         struct ctl_table *new, **prevp;
1870         unsigned int n, npath;
1871         struct ctl_table_set *set;
1872
1873         /* Count the path components */
1874         for (npath = 0; path[npath].procname; ++npath)
1875                 ;
1876
1877         /*
1878          * For each path component, allocate a 2-element ctl_table array.
1879          * The first array element will be filled with the sysctl entry
1880          * for this, the second will be the sentinel (procname == 0).
1881          *
1882          * We allocate everything in one go so that we don't have to
1883          * worry about freeing additional memory in unregister_sysctl_table.
1884          */
1885         header = kzalloc(sizeof(struct ctl_table_header) +
1886                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1887         if (!header)
1888                 return NULL;
1889
1890         new = (struct ctl_table *) (header + 1);
1891
1892         /* Now connect the dots */
1893         prevp = &header->ctl_table;
1894         for (n = 0; n < npath; ++n, ++path) {
1895                 /* Copy the procname */
1896                 new->procname = path->procname;
1897                 new->mode     = 0555;
1898
1899                 *prevp = new;
1900                 prevp = &new->child;
1901
1902                 new += 2;
1903         }
1904         *prevp = table;
1905         header->ctl_table_arg = table;
1906
1907         INIT_LIST_HEAD(&header->ctl_entry);
1908         header->used = 0;
1909         header->unregistering = NULL;
1910         header->root = root;
1911         sysctl_set_parent(NULL, header->ctl_table);
1912         header->count = 1;
1913 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1914         if (sysctl_check_table(namespaces, header->ctl_table)) {
1915                 kfree(header);
1916                 return NULL;
1917         }
1918 #endif
1919         spin_lock(&sysctl_lock);
1920         header->set = lookup_header_set(root, namespaces);
1921         header->attached_by = header->ctl_table;
1922         header->attached_to = root_table;
1923         header->parent = &root_table_header;
1924         for (set = header->set; set; set = set->parent) {
1925                 struct ctl_table_header *p;
1926                 list_for_each_entry(p, &set->list, ctl_entry) {
1927                         if (p->unregistering)
1928                                 continue;
1929                         try_attach(p, header);
1930                 }
1931         }
1932         header->parent->count++;
1933         list_add_tail(&header->ctl_entry, &header->set->list);
1934         spin_unlock(&sysctl_lock);
1935
1936         return header;
1937 }
1938
1939 /**
1940  * register_sysctl_table_path - register a sysctl table hierarchy
1941  * @path: The path to the directory the sysctl table is in.
1942  * @table: the top-level table structure
1943  *
1944  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1945  * array. A completely 0 filled entry terminates the table.
1946  *
1947  * See __register_sysctl_paths for more details.
1948  */
1949 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1950                                                 struct ctl_table *table)
1951 {
1952         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1953                                         path, table);
1954 }
1955
1956 /**
1957  * register_sysctl_table - register a sysctl table hierarchy
1958  * @table: the top-level table structure
1959  *
1960  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1961  * array. A completely 0 filled entry terminates the table.
1962  *
1963  * See register_sysctl_paths for more details.
1964  */
1965 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1966 {
1967         static const struct ctl_path null_path[] = { {} };
1968
1969         return register_sysctl_paths(null_path, table);
1970 }
1971
1972 /**
1973  * unregister_sysctl_table - unregister a sysctl table hierarchy
1974  * @header: the header returned from register_sysctl_table
1975  *
1976  * Unregisters the sysctl table and all children. proc entries may not
1977  * actually be removed until they are no longer used by anyone.
1978  */
1979 void unregister_sysctl_table(struct ctl_table_header * header)
1980 {
1981         might_sleep();
1982
1983         if (header == NULL)
1984                 return;
1985
1986         spin_lock(&sysctl_lock);
1987         start_unregistering(header);
1988         if (!--header->parent->count) {
1989                 WARN_ON(1);
1990                 kfree_rcu(header->parent, rcu);
1991         }
1992         if (!--header->count)
1993                 kfree_rcu(header, rcu);
1994         spin_unlock(&sysctl_lock);
1995 }
1996
1997 int sysctl_is_seen(struct ctl_table_header *p)
1998 {
1999         struct ctl_table_set *set = p->set;
2000         int res;
2001         spin_lock(&sysctl_lock);
2002         if (p->unregistering)
2003                 res = 0;
2004         else if (!set->is_seen)
2005                 res = 1;
2006         else
2007                 res = set->is_seen(set);
2008         spin_unlock(&sysctl_lock);
2009         return res;
2010 }
2011
2012 void setup_sysctl_set(struct ctl_table_set *p,
2013         struct ctl_table_set *parent,
2014         int (*is_seen)(struct ctl_table_set *))
2015 {
2016         INIT_LIST_HEAD(&p->list);
2017         p->parent = parent ? parent : &sysctl_table_root.default_set;
2018         p->is_seen = is_seen;
2019 }
2020
2021 #else /* !CONFIG_SYSCTL */
2022 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2023 {
2024         return NULL;
2025 }
2026
2027 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2028                                                     struct ctl_table *table)
2029 {
2030         return NULL;
2031 }
2032
2033 void unregister_sysctl_table(struct ctl_table_header * table)
2034 {
2035 }
2036
2037 void setup_sysctl_set(struct ctl_table_set *p,
2038         struct ctl_table_set *parent,
2039         int (*is_seen)(struct ctl_table_set *))
2040 {
2041 }
2042
2043 void sysctl_head_put(struct ctl_table_header *head)
2044 {
2045 }
2046
2047 #endif /* CONFIG_SYSCTL */
2048
2049 /*
2050  * /proc/sys support
2051  */
2052
2053 #ifdef CONFIG_PROC_SYSCTL
2054
2055 static int _proc_do_string(void* data, int maxlen, int write,
2056                            void __user *buffer,
2057                            size_t *lenp, loff_t *ppos)
2058 {
2059         size_t len;
2060         char __user *p;
2061         char c;
2062
2063         if (!data || !maxlen || !*lenp) {
2064                 *lenp = 0;
2065                 return 0;
2066         }
2067
2068         if (write) {
2069                 len = 0;
2070                 p = buffer;
2071                 while (len < *lenp) {
2072                         if (get_user(c, p++))
2073                                 return -EFAULT;
2074                         if (c == 0 || c == '\n')
2075                                 break;
2076                         len++;
2077                 }
2078                 if (len >= maxlen)
2079                         len = maxlen-1;
2080                 if(copy_from_user(data, buffer, len))
2081                         return -EFAULT;
2082                 ((char *) data)[len] = 0;
2083                 *ppos += *lenp;
2084         } else {
2085                 len = strlen(data);
2086                 if (len > maxlen)
2087                         len = maxlen;
2088
2089                 if (*ppos > len) {
2090                         *lenp = 0;
2091                         return 0;
2092                 }
2093
2094                 data += *ppos;
2095                 len  -= *ppos;
2096
2097                 if (len > *lenp)
2098                         len = *lenp;
2099                 if (len)
2100                         if(copy_to_user(buffer, data, len))
2101                                 return -EFAULT;
2102                 if (len < *lenp) {
2103                         if(put_user('\n', ((char __user *) buffer) + len))
2104                                 return -EFAULT;
2105                         len++;
2106                 }
2107                 *lenp = len;
2108                 *ppos += len;
2109         }
2110         return 0;
2111 }
2112
2113 /**
2114  * proc_dostring - read a string sysctl
2115  * @table: the sysctl table
2116  * @write: %TRUE if this is a write to the sysctl file
2117  * @buffer: the user buffer
2118  * @lenp: the size of the user buffer
2119  * @ppos: file position
2120  *
2121  * Reads/writes a string from/to the user buffer. If the kernel
2122  * buffer provided is not large enough to hold the string, the
2123  * string is truncated. The copied string is %NULL-terminated.
2124  * If the string is being read by the user process, it is copied
2125  * and a newline '\n' is added. It is truncated if the buffer is
2126  * not large enough.
2127  *
2128  * Returns 0 on success.
2129  */
2130 int proc_dostring(struct ctl_table *table, int write,
2131                   void __user *buffer, size_t *lenp, loff_t *ppos)
2132 {
2133         return _proc_do_string(table->data, table->maxlen, write,
2134                                buffer, lenp, ppos);
2135 }
2136
2137 static size_t proc_skip_spaces(char **buf)
2138 {
2139         size_t ret;
2140         char *tmp = skip_spaces(*buf);
2141         ret = tmp - *buf;
2142         *buf = tmp;
2143         return ret;
2144 }
2145
2146 static void proc_skip_char(char **buf, size_t *size, const char v)
2147 {
2148         while (*size) {
2149                 if (**buf != v)
2150                         break;
2151                 (*size)--;
2152                 (*buf)++;
2153         }
2154 }
2155
2156 #define TMPBUFLEN 22
2157 /**
2158  * proc_get_long - reads an ASCII formatted integer from a user buffer
2159  *
2160  * @buf: a kernel buffer
2161  * @size: size of the kernel buffer
2162  * @val: this is where the number will be stored
2163  * @neg: set to %TRUE if number is negative
2164  * @perm_tr: a vector which contains the allowed trailers
2165  * @perm_tr_len: size of the perm_tr vector
2166  * @tr: pointer to store the trailer character
2167  *
2168  * In case of success %0 is returned and @buf and @size are updated with
2169  * the amount of bytes read. If @tr is non-NULL and a trailing
2170  * character exists (size is non-zero after returning from this
2171  * function), @tr is updated with the trailing character.
2172  */
2173 static int proc_get_long(char **buf, size_t *size,
2174                           unsigned long *val, bool *neg,
2175                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2176 {
2177         int len;
2178         char *p, tmp[TMPBUFLEN];
2179
2180         if (!*size)
2181                 return -EINVAL;
2182
2183         len = *size;
2184         if (len > TMPBUFLEN - 1)
2185                 len = TMPBUFLEN - 1;
2186
2187         memcpy(tmp, *buf, len);
2188
2189         tmp[len] = 0;
2190         p = tmp;
2191         if (*p == '-' && *size > 1) {
2192                 *neg = true;
2193                 p++;
2194         } else
2195                 *neg = false;
2196         if (!isdigit(*p))
2197                 return -EINVAL;
2198
2199         *val = simple_strtoul(p, &p, 0);
2200
2201         len = p - tmp;
2202
2203         /* We don't know if the next char is whitespace thus we may accept
2204          * invalid integers (e.g. 1234...a) or two integers instead of one
2205          * (e.g. 123...1). So lets not allow such large numbers. */
2206         if (len == TMPBUFLEN - 1)
2207                 return -EINVAL;
2208
2209         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2210                 return -EINVAL;
2211
2212         if (tr && (len < *size))
2213                 *tr = *p;
2214
2215         *buf += len;
2216         *size -= len;
2217
2218         return 0;
2219 }
2220
2221 /**
2222  * proc_put_long - converts an integer to a decimal ASCII formatted string
2223  *
2224  * @buf: the user buffer
2225  * @size: the size of the user buffer
2226  * @val: the integer to be converted
2227  * @neg: sign of the number, %TRUE for negative
2228  *
2229  * In case of success %0 is returned and @buf and @size are updated with
2230  * the amount of bytes written.
2231  */
2232 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2233                           bool neg)
2234 {
2235         int len;
2236         char tmp[TMPBUFLEN], *p = tmp;
2237
2238         sprintf(p, "%s%lu", neg ? "-" : "", val);
2239         len = strlen(tmp);
2240         if (len > *size)
2241                 len = *size;
2242         if (copy_to_user(*buf, tmp, len))
2243                 return -EFAULT;
2244         *size -= len;
2245         *buf += len;
2246         return 0;
2247 }
2248 #undef TMPBUFLEN
2249
2250 static int proc_put_char(void __user **buf, size_t *size, char c)
2251 {
2252         if (*size) {
2253                 char __user **buffer = (char __user **)buf;
2254                 if (put_user(c, *buffer))
2255                         return -EFAULT;
2256                 (*size)--, (*buffer)++;
2257                 *buf = *buffer;
2258         }
2259         return 0;
2260 }
2261
2262 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2263                                  int *valp,
2264                                  int write, void *data)
2265 {
2266         if (write) {
2267                 *valp = *negp ? -*lvalp : *lvalp;
2268         } else {
2269                 int val = *valp;
2270                 if (val < 0) {
2271                         *negp = true;
2272                         *lvalp = (unsigned long)-val;
2273                 } else {
2274                         *negp = false;
2275                         *lvalp = (unsigned long)val;
2276                 }
2277         }
2278         return 0;
2279 }
2280
2281 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2282
2283 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2284                   int write, void __user *buffer,
2285                   size_t *lenp, loff_t *ppos,
2286                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2287                               int write, void *data),
2288                   void *data)
2289 {
2290         int *i, vleft, first = 1, err = 0;
2291         unsigned long page = 0;
2292         size_t left;
2293         char *kbuf;
2294
2295         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2296                 *lenp = 0;
2297                 return 0;
2298         }
2299
2300         i = (int *) tbl_data;
2301         vleft = table->maxlen / sizeof(*i);
2302         left = *lenp;
2303
2304         if (!conv)
2305                 conv = do_proc_dointvec_conv;
2306
2307         if (write) {
2308                 if (left > PAGE_SIZE - 1)
2309                         left = PAGE_SIZE - 1;
2310                 page = __get_free_page(GFP_TEMPORARY);
2311                 kbuf = (char *) page;
2312                 if (!kbuf)
2313                         return -ENOMEM;
2314                 if (copy_from_user(kbuf, buffer, left)) {
2315                         err = -EFAULT;
2316                         goto free;
2317                 }
2318                 kbuf[left] = 0;
2319         }
2320
2321         for (; left && vleft--; i++, first=0) {
2322                 unsigned long lval;
2323                 bool neg;
2324
2325                 if (write) {
2326                         left -= proc_skip_spaces(&kbuf);
2327
2328                         if (!left)
2329                                 break;
2330                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2331                                              proc_wspace_sep,
2332                                              sizeof(proc_wspace_sep), NULL);
2333                         if (err)
2334                                 break;
2335                         if (conv(&neg, &lval, i, 1, data)) {
2336                                 err = -EINVAL;
2337                                 break;
2338                         }
2339                 } else {
2340                         if (conv(&neg, &lval, i, 0, data)) {
2341                                 err = -EINVAL;
2342                                 break;
2343                         }
2344                         if (!first)
2345                                 err = proc_put_char(&buffer, &left, '\t');
2346                         if (err)
2347                                 break;
2348                         err = proc_put_long(&buffer, &left, lval, neg);
2349                         if (err)
2350                                 break;
2351                 }
2352         }
2353
2354         if (!write && !first && left && !err)
2355                 err = proc_put_char(&buffer, &left, '\n');
2356         if (write && !err && left)
2357                 left -= proc_skip_spaces(&kbuf);
2358 free:
2359         if (write) {
2360                 free_page(page);
2361                 if (first)
2362                         return err ? : -EINVAL;
2363         }
2364         *lenp -= left;
2365         *ppos += *lenp;
2366         return err;
2367 }
2368
2369 static int do_proc_dointvec(struct ctl_table *table, int write,
2370                   void __user *buffer, size_t *lenp, loff_t *ppos,
2371                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2372                               int write, void *data),
2373                   void *data)
2374 {
2375         return __do_proc_dointvec(table->data, table, write,
2376                         buffer, lenp, ppos, conv, data);
2377 }
2378
2379 /**
2380  * proc_dointvec - read a vector of integers
2381  * @table: the sysctl table
2382  * @write: %TRUE if this is a write to the sysctl file
2383  * @buffer: the user buffer
2384  * @lenp: the size of the user buffer
2385  * @ppos: file position
2386  *
2387  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2388  * values from/to the user buffer, treated as an ASCII string.
2389  *
2390  * Returns 0 on success.
2391  */
2392 int proc_dointvec(struct ctl_table *table, int write,
2393                      void __user *buffer, size_t *lenp, loff_t *ppos)
2394 {
2395     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2396                             NULL,NULL);
2397 }
2398
2399 /*
2400  * Taint values can only be increased
2401  * This means we can safely use a temporary.
2402  */
2403 static int proc_taint(struct ctl_table *table, int write,
2404                                void __user *buffer, size_t *lenp, loff_t *ppos)
2405 {
2406         struct ctl_table t;
2407         unsigned long tmptaint = get_taint();
2408         int err;
2409
2410         if (write && !capable(CAP_SYS_ADMIN))
2411                 return -EPERM;
2412
2413         t = *table;
2414         t.data = &tmptaint;
2415         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2416         if (err < 0)
2417                 return err;
2418
2419         if (write) {
2420                 /*
2421                  * Poor man's atomic or. Not worth adding a primitive
2422                  * to everyone's atomic.h for this
2423                  */
2424                 int i;
2425                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2426                         if ((tmptaint >> i) & 1)
2427                                 add_taint(i);
2428                 }
2429         }
2430
2431         return err;
2432 }
2433
2434 #ifdef CONFIG_PRINTK
2435 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2436                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2437 {
2438         if (write && !capable(CAP_SYS_ADMIN))
2439                 return -EPERM;
2440
2441         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2442 }
2443 #endif
2444
2445 struct do_proc_dointvec_minmax_conv_param {
2446         int *min;
2447         int *max;
2448 };
2449
2450 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2451                                         int *valp,
2452                                         int write, void *data)
2453 {
2454         struct do_proc_dointvec_minmax_conv_param *param = data;
2455         if (write) {
2456                 int val = *negp ? -*lvalp : *lvalp;
2457                 if ((param->min && *param->min > val) ||
2458                     (param->max && *param->max < val))
2459                         return -EINVAL;
2460                 *valp = val;
2461         } else {
2462                 int val = *valp;
2463                 if (val < 0) {
2464                         *negp = true;
2465                         *lvalp = (unsigned long)-val;
2466                 } else {
2467                         *negp = false;
2468                         *lvalp = (unsigned long)val;
2469                 }
2470         }
2471         return 0;
2472 }
2473
2474 /**
2475  * proc_dointvec_minmax - read a vector of integers with min/max values
2476  * @table: the sysctl table
2477  * @write: %TRUE if this is a write to the sysctl file
2478  * @buffer: the user buffer
2479  * @lenp: the size of the user buffer
2480  * @ppos: file position
2481  *
2482  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2483  * values from/to the user buffer, treated as an ASCII string.
2484  *
2485  * This routine will ensure the values are within the range specified by
2486  * table->extra1 (min) and table->extra2 (max).
2487  *
2488  * Returns 0 on success.
2489  */
2490 int proc_dointvec_minmax(struct ctl_table *table, int write,
2491                   void __user *buffer, size_t *lenp, loff_t *ppos)
2492 {
2493         struct do_proc_dointvec_minmax_conv_param param = {
2494                 .min = (int *) table->extra1,
2495                 .max = (int *) table->extra2,
2496         };
2497         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2498                                 do_proc_dointvec_minmax_conv, &param);
2499 }
2500
2501 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2502                                      void __user *buffer,
2503                                      size_t *lenp, loff_t *ppos,
2504                                      unsigned long convmul,
2505                                      unsigned long convdiv)
2506 {
2507         unsigned long *i, *min, *max;
2508         int vleft, first = 1, err = 0;
2509         unsigned long page = 0;
2510         size_t left;
2511         char *kbuf;
2512
2513         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2514                 *lenp = 0;
2515                 return 0;
2516         }
2517
2518         i = (unsigned long *) data;
2519         min = (unsigned long *) table->extra1;
2520         max = (unsigned long *) table->extra2;
2521         vleft = table->maxlen / sizeof(unsigned long);
2522         left = *lenp;
2523
2524         if (write) {
2525                 if (left > PAGE_SIZE - 1)
2526                         left = PAGE_SIZE - 1;
2527                 page = __get_free_page(GFP_TEMPORARY);
2528                 kbuf = (char *) page;
2529                 if (!kbuf)
2530                         return -ENOMEM;
2531                 if (copy_from_user(kbuf, buffer, left)) {
2532                         err = -EFAULT;
2533                         goto free;
2534                 }
2535                 kbuf[left] = 0;
2536         }
2537
2538         for (; left && vleft--; i++, first = 0) {
2539                 unsigned long val;
2540
2541                 if (write) {
2542                         bool neg;
2543
2544                         left -= proc_skip_spaces(&kbuf);
2545
2546                         err = proc_get_long(&kbuf, &left, &val, &neg,
2547                                              proc_wspace_sep,
2548                                              sizeof(proc_wspace_sep), NULL);
2549                         if (err)
2550                                 break;
2551                         if (neg)
2552                                 continue;
2553                         if ((min && val < *min) || (max && val > *max))
2554                                 continue;
2555                         *i = val;
2556                 } else {
2557                         val = convdiv * (*i) / convmul;
2558                         if (!first)
2559                                 err = proc_put_char(&buffer, &left, '\t');
2560                         err = proc_put_long(&buffer, &left, val, false);
2561                         if (err)
2562                                 break;
2563                 }
2564         }
2565
2566         if (!write && !first && left && !err)
2567                 err = proc_put_char(&buffer, &left, '\n');
2568         if (write && !err)
2569                 left -= proc_skip_spaces(&kbuf);
2570 free:
2571         if (write) {
2572                 free_page(page);
2573                 if (first)
2574                         return err ? : -EINVAL;
2575         }
2576         *lenp -= left;
2577         *ppos += *lenp;
2578         return err;
2579 }
2580
2581 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2582                                      void __user *buffer,
2583                                      size_t *lenp, loff_t *ppos,
2584                                      unsigned long convmul,
2585                                      unsigned long convdiv)
2586 {
2587         return __do_proc_doulongvec_minmax(table->data, table, write,
2588                         buffer, lenp, ppos, convmul, convdiv);
2589 }
2590
2591 /**
2592  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2593  * @table: the sysctl table
2594  * @write: %TRUE if this is a write to the sysctl file
2595  * @buffer: the user buffer
2596  * @lenp: the size of the user buffer
2597  * @ppos: file position
2598  *
2599  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2600  * values from/to the user buffer, treated as an ASCII string.
2601  *
2602  * This routine will ensure the values are within the range specified by
2603  * table->extra1 (min) and table->extra2 (max).
2604  *
2605  * Returns 0 on success.
2606  */
2607 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2608                            void __user *buffer, size_t *lenp, loff_t *ppos)
2609 {
2610     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2611 }
2612
2613 /**
2614  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2615  * @table: the sysctl table
2616  * @write: %TRUE if this is a write to the sysctl file
2617  * @buffer: the user buffer
2618  * @lenp: the size of the user buffer
2619  * @ppos: file position
2620  *
2621  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2622  * values from/to the user buffer, treated as an ASCII string. The values
2623  * are treated as milliseconds, and converted to jiffies when they are stored.
2624  *
2625  * This routine will ensure the values are within the range specified by
2626  * table->extra1 (min) and table->extra2 (max).
2627  *
2628  * Returns 0 on success.
2629  */
2630 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2631                                       void __user *buffer,
2632                                       size_t *lenp, loff_t *ppos)
2633 {
2634     return do_proc_doulongvec_minmax(table, write, buffer,
2635                                      lenp, ppos, HZ, 1000l);
2636 }
2637
2638
2639 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2640                                          int *valp,
2641                                          int write, void *data)
2642 {
2643         if (write) {
2644                 if (*lvalp > LONG_MAX / HZ)
2645                         return 1;
2646                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2647         } else {
2648                 int val = *valp;
2649                 unsigned long lval;
2650                 if (val < 0) {
2651                         *negp = true;
2652                         lval = (unsigned long)-val;
2653                 } else {
2654                         *negp = false;
2655                         lval = (unsigned long)val;
2656                 }
2657                 *lvalp = lval / HZ;
2658         }
2659         return 0;
2660 }
2661
2662 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2663                                                 int *valp,
2664                                                 int write, void *data)
2665 {
2666         if (write) {
2667                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2668                         return 1;
2669                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2670         } else {
2671                 int val = *valp;
2672                 unsigned long lval;
2673                 if (val < 0) {
2674                         *negp = true;
2675                         lval = (unsigned long)-val;
2676                 } else {
2677                         *negp = false;
2678                         lval = (unsigned long)val;
2679                 }
2680                 *lvalp = jiffies_to_clock_t(lval);
2681         }
2682         return 0;
2683 }
2684
2685 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2686                                             int *valp,
2687                                             int write, void *data)
2688 {
2689         if (write) {
2690                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2691         } else {
2692                 int val = *valp;
2693                 unsigned long lval;
2694                 if (val < 0) {
2695                         *negp = true;
2696                         lval = (unsigned long)-val;
2697                 } else {
2698                         *negp = false;
2699                         lval = (unsigned long)val;
2700                 }
2701                 *lvalp = jiffies_to_msecs(lval);
2702         }
2703         return 0;
2704 }
2705
2706 /**
2707  * proc_dointvec_jiffies - read a vector of integers as seconds
2708  * @table: the sysctl table
2709  * @write: %TRUE if this is a write to the sysctl file
2710  * @buffer: the user buffer
2711  * @lenp: the size of the user buffer
2712  * @ppos: file position
2713  *
2714  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715  * values from/to the user buffer, treated as an ASCII string.
2716  * The values read are assumed to be in seconds, and are converted into
2717  * jiffies.
2718  *
2719  * Returns 0 on success.
2720  */
2721 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2722                           void __user *buffer, size_t *lenp, loff_t *ppos)
2723 {
2724     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2725                             do_proc_dointvec_jiffies_conv,NULL);
2726 }
2727
2728 /**
2729  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2730  * @table: the sysctl table
2731  * @write: %TRUE if this is a write to the sysctl file
2732  * @buffer: the user buffer
2733  * @lenp: the size of the user buffer
2734  * @ppos: pointer to the file position
2735  *
2736  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2737  * values from/to the user buffer, treated as an ASCII string.
2738  * The values read are assumed to be in 1/USER_HZ seconds, and
2739  * are converted into jiffies.
2740  *
2741  * Returns 0 on success.
2742  */
2743 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2744                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2745 {
2746     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2747                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2748 }
2749
2750 /**
2751  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2752  * @table: the sysctl table
2753  * @write: %TRUE if this is a write to the sysctl file
2754  * @buffer: the user buffer
2755  * @lenp: the size of the user buffer
2756  * @ppos: file position
2757  * @ppos: the current position in the file
2758  *
2759  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2760  * values from/to the user buffer, treated as an ASCII string.
2761  * The values read are assumed to be in 1/1000 seconds, and
2762  * are converted into jiffies.
2763  *
2764  * Returns 0 on success.
2765  */
2766 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2767                              void __user *buffer, size_t *lenp, loff_t *ppos)
2768 {
2769         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2770                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2771 }
2772
2773 static int proc_do_cad_pid(struct ctl_table *table, int write,
2774                            void __user *buffer, size_t *lenp, loff_t *ppos)
2775 {
2776         struct pid *new_pid;
2777         pid_t tmp;
2778         int r;
2779
2780         tmp = pid_vnr(cad_pid);
2781
2782         r = __do_proc_dointvec(&tmp, table, write, buffer,
2783                                lenp, ppos, NULL, NULL);
2784         if (r || !write)
2785                 return r;
2786
2787         new_pid = find_get_pid(tmp);
2788         if (!new_pid)
2789                 return -ESRCH;
2790
2791         put_pid(xchg(&cad_pid, new_pid));
2792         return 0;
2793 }
2794
2795 /**
2796  * proc_do_large_bitmap - read/write from/to a large bitmap
2797  * @table: the sysctl table
2798  * @write: %TRUE if this is a write to the sysctl file
2799  * @buffer: the user buffer
2800  * @lenp: the size of the user buffer
2801  * @ppos: file position
2802  *
2803  * The bitmap is stored at table->data and the bitmap length (in bits)
2804  * in table->maxlen.
2805  *
2806  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2807  * large bitmaps may be represented in a compact manner. Writing into
2808  * the file will clear the bitmap then update it with the given input.
2809  *
2810  * Returns 0 on success.
2811  */
2812 int proc_do_large_bitmap(struct ctl_table *table, int write,
2813                          void __user *buffer, size_t *lenp, loff_t *ppos)
2814 {
2815         int err = 0;
2816         bool first = 1;
2817         size_t left = *lenp;
2818         unsigned long bitmap_len = table->maxlen;
2819         unsigned long *bitmap = (unsigned long *) table->data;
2820         unsigned long *tmp_bitmap = NULL;
2821         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2822
2823         if (!bitmap_len || !left || (*ppos && !write)) {
2824                 *lenp = 0;
2825                 return 0;
2826         }
2827
2828         if (write) {
2829                 unsigned long page = 0;
2830                 char *kbuf;
2831
2832                 if (left > PAGE_SIZE - 1)
2833                         left = PAGE_SIZE - 1;
2834
2835                 page = __get_free_page(GFP_TEMPORARY);
2836                 kbuf = (char *) page;
2837                 if (!kbuf)
2838                         return -ENOMEM;
2839                 if (copy_from_user(kbuf, buffer, left)) {
2840                         free_page(page);
2841                         return -EFAULT;
2842                 }
2843                 kbuf[left] = 0;
2844
2845                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2846                                      GFP_KERNEL);
2847                 if (!tmp_bitmap) {
2848                         free_page(page);
2849                         return -ENOMEM;
2850                 }
2851                 proc_skip_char(&kbuf, &left, '\n');
2852                 while (!err && left) {
2853                         unsigned long val_a, val_b;
2854                         bool neg;
2855
2856                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2857                                              sizeof(tr_a), &c);
2858                         if (err)
2859                                 break;
2860                         if (val_a >= bitmap_len || neg) {
2861                                 err = -EINVAL;
2862                                 break;
2863                         }
2864
2865                         val_b = val_a;
2866                         if (left) {
2867                                 kbuf++;
2868                                 left--;
2869                         }
2870
2871                         if (c == '-') {
2872                                 err = proc_get_long(&kbuf, &left, &val_b,
2873                                                      &neg, tr_b, sizeof(tr_b),
2874                                                      &c);
2875                                 if (err)
2876                                         break;
2877                                 if (val_b >= bitmap_len || neg ||
2878                                     val_a > val_b) {
2879                                         err = -EINVAL;
2880                                         break;
2881                                 }
2882                                 if (left) {
2883                                         kbuf++;
2884                                         left--;
2885                                 }
2886                         }
2887
2888                         while (val_a <= val_b)
2889                                 set_bit(val_a++, tmp_bitmap);
2890
2891                         first = 0;
2892                         proc_skip_char(&kbuf, &left, '\n');
2893                 }
2894                 free_page(page);
2895         } else {
2896                 unsigned long bit_a, bit_b = 0;
2897
2898                 while (left) {
2899                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2900                         if (bit_a >= bitmap_len)
2901                                 break;
2902                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2903                                                    bit_a + 1) - 1;
2904
2905                         if (!first) {
2906                                 err = proc_put_char(&buffer, &left, ',');
2907                                 if (err)
2908                                         break;
2909                         }
2910                         err = proc_put_long(&buffer, &left, bit_a, false);
2911                         if (err)
2912                                 break;
2913                         if (bit_a != bit_b) {
2914                                 err = proc_put_char(&buffer, &left, '-');
2915                                 if (err)
2916                                         break;
2917                                 err = proc_put_long(&buffer, &left, bit_b, false);
2918                                 if (err)
2919                                         break;
2920                         }
2921
2922                         first = 0; bit_b++;
2923                 }
2924                 if (!err)
2925                         err = proc_put_char(&buffer, &left, '\n');
2926         }
2927
2928         if (!err) {
2929                 if (write) {
2930                         if (*ppos)
2931                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2932                         else
2933                                 memcpy(bitmap, tmp_bitmap,
2934                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2935                 }
2936                 kfree(tmp_bitmap);
2937                 *lenp -= left;
2938                 *ppos += *lenp;
2939                 return 0;
2940         } else {
2941                 kfree(tmp_bitmap);
2942                 return err;
2943         }
2944 }
2945
2946 #else /* CONFIG_PROC_SYSCTL */
2947
2948 int proc_dostring(struct ctl_table *table, int write,
2949                   void __user *buffer, size_t *lenp, loff_t *ppos)
2950 {
2951         return -ENOSYS;
2952 }
2953
2954 int proc_dointvec(struct ctl_table *table, int write,
2955                   void __user *buffer, size_t *lenp, loff_t *ppos)
2956 {
2957         return -ENOSYS;
2958 }
2959
2960 int proc_dointvec_minmax(struct ctl_table *table, int write,
2961                     void __user *buffer, size_t *lenp, loff_t *ppos)
2962 {
2963         return -ENOSYS;
2964 }
2965
2966 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2967                     void __user *buffer, size_t *lenp, loff_t *ppos)
2968 {
2969         return -ENOSYS;
2970 }
2971
2972 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2973                     void __user *buffer, size_t *lenp, loff_t *ppos)
2974 {
2975         return -ENOSYS;
2976 }
2977
2978 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2979                              void __user *buffer, size_t *lenp, loff_t *ppos)
2980 {
2981         return -ENOSYS;
2982 }
2983
2984 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2985                     void __user *buffer, size_t *lenp, loff_t *ppos)
2986 {
2987         return -ENOSYS;
2988 }
2989
2990 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2991                                       void __user *buffer,
2992                                       size_t *lenp, loff_t *ppos)
2993 {
2994     return -ENOSYS;
2995 }
2996
2997
2998 #endif /* CONFIG_PROC_SYSCTL */
2999
3000 /*
3001  * No sense putting this after each symbol definition, twice,
3002  * exception granted :-)
3003  */
3004 EXPORT_SYMBOL(proc_dointvec);
3005 EXPORT_SYMBOL(proc_dointvec_jiffies);
3006 EXPORT_SYMBOL(proc_dointvec_minmax);
3007 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3008 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3009 EXPORT_SYMBOL(proc_dostring);
3010 EXPORT_SYMBOL(proc_doulongvec_minmax);
3011 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3012 EXPORT_SYMBOL(register_sysctl_table);
3013 EXPORT_SYMBOL(register_sysctl_paths);
3014 EXPORT_SYMBOL(unregister_sysctl_table);