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/proc_fs.h>
  27 #include <linux/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/kmemcheck.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/hugetlb.h>
  40 #include <linux/initrd.h>
  41 #include <linux/key.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/vmstat.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50 #include <linux/ftrace.h>
  51 #include <linux/slow-work.h>
  52 #include <linux/perf_event.h>
  53
  54 #include <asm/uaccess.h>
  55 #include <asm/processor.h>
  56
  57 #ifdef CONFIG_X86
  58 #include <asm/nmi.h>
  59 #include <asm/stacktrace.h>
  60 #include <asm/io.h>
  61 #endif
  62
  63 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  64
  65 #if defined(CONFIG_SYSCTL)
  66
  67 /* External variables not in a header file. */
  68 extern int C_A_D;
  69 extern int print_fatal_signals;
  70 extern int sysctl_overcommit_memory;
  71 extern int sysctl_overcommit_ratio;
  72 extern int sysctl_panic_on_oom;
  73 extern int sysctl_oom_kill_allocating_task;
  74 extern int sysctl_oom_dump_tasks;
  75 extern int max_threads;
  76 extern int core_uses_pid;
  77 extern int suid_dumpable;
  78 extern char core_pattern[];
  79 extern unsigned int core_pipe_limit;
  80 extern int pid_max;
  81 extern int min_free_kbytes;
  82 extern int min_free_order_shift;
  83 extern int pid_max_min, pid_max_max;
  84 extern int sysctl_drop_caches;
  85 extern int percpu_pagelist_fraction;
  86 extern int compat_log;
  87 extern int latencytop_enabled;
  88 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  89 #ifndef CONFIG_MMU
  90 extern int sysctl_nr_trim_pages;
  91 #endif
  92 #ifdef CONFIG_RCU_TORTURE_TEST
  93 extern int rcutorture_runnable;
  94 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  95 #ifdef CONFIG_BLOCK
  96 extern int blk_iopoll_enabled;
  97 #endif
  98
  99 /* Constants used for minimum and  maximum */
 100 #ifdef CONFIG_DETECT_SOFTLOCKUP
 101 static int sixty = 60;
 102 static int neg_one = -1;
 103 #endif
 104
 105 static int zero;
 106 static int __maybe_unused one = 1;
 107 static int __maybe_unused two = 2;
 108 static unsigned long one_ul = 1;
 109 static int one_hundred = 100;
 110 #ifdef CONFIG_PRINTK
 111 static int ten_thousand = 10000;
 112 #endif
 113
 114 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 115 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 116
 117 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 118 static int maxolduid = 65535;
 119 static int minolduid;
 120 static int min_percpu_pagelist_fract = 8;
 121
 122 static int ngroups_max = NGROUPS_MAX;
 123
 124 #ifdef CONFIG_MODULES
 125 extern char modprobe_path[];
 126 extern int modules_disabled;
 127 #endif
 128 #ifdef CONFIG_CHR_DEV_SG
 129 extern int sg_big_buff;
 130 #endif
 131
 132 #ifdef CONFIG_SPARC
 133 #include <asm/system.h>
 134 #endif
 135
 136 #ifdef CONFIG_SPARC64
 137 extern int sysctl_tsb_ratio;
 138 #endif
 139
 140 #ifdef __hppa__
 141 extern int pwrsw_enabled;
 142 extern int unaligned_enabled;
 143 #endif
 144
 145 #ifdef CONFIG_S390
 146 #ifdef CONFIG_MATHEMU
 147 extern int sysctl_ieee_emulation_warnings;
 148 #endif
 149 extern int sysctl_userprocess_debug;
 150 extern int spin_retry;
 151 #endif
 152
 153 #ifdef CONFIG_BSD_PROCESS_ACCT
 154 extern int acct_parm[];
 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_RT_MUTEXES
 163 extern int max_lock_depth;
 164 #endif
 165
 166 #ifdef CONFIG_PROC_SYSCTL
 167 static int proc_do_cad_pid(struct ctl_table *table, int write,
 168                   void __user *buffer, size_t *lenp, loff_t *ppos);
 169 static int proc_taint(struct ctl_table *table, int write,
 170                                void __user *buffer, size_t *lenp, loff_t *ppos);
 171 #endif
 172
 173 static struct ctl_table root_table[];
 174 static struct ctl_table_root sysctl_table_root;
 175 static struct ctl_table_header root_table_header = {
 176         .count = 1,
 177         .ctl_table = root_table,
 178         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 179         .root = &sysctl_table_root,
 180         .set = &sysctl_table_root.default_set,
 181 };
 182 static struct ctl_table_root sysctl_table_root = {
 183         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 184         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 185 };
 186
 187 static struct ctl_table kern_table[];
 188 static struct ctl_table vm_table[];
 189 static struct ctl_table fs_table[];
 190 static struct ctl_table debug_table[];
 191 static struct ctl_table dev_table[];
 192 extern struct ctl_table random_table[];
 193 #ifdef CONFIG_INOTIFY_USER
 194 extern struct ctl_table inotify_table[];
 195 #endif
 196 #ifdef CONFIG_EPOLL
 197 extern struct ctl_table epoll_table[];
 198 #endif
 199
 200 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 201 int sysctl_legacy_va_layout;
 202 #endif
 203
 204 extern int prove_locking;
 205 extern int lock_stat;
 206
 207 /* The default sysctl tables: */
 208
 209 static struct ctl_table root_table[] = {
 210         {
 211                 .ctl_name       = CTL_KERN,
 212                 .procname       = "kernel",
 213                 .mode           = 0555,
 214                 .child          = kern_table,
 215         },
 216         {
 217                 .ctl_name       = CTL_VM,
 218                 .procname       = "vm",
 219                 .mode           = 0555,
 220                 .child          = vm_table,
 221         },
 222         {
 223                 .ctl_name       = CTL_FS,
 224                 .procname       = "fs",
 225                 .mode           = 0555,
 226                 .child          = fs_table,
 227         },
 228         {
 229                 .ctl_name       = CTL_DEBUG,
 230                 .procname       = "debug",
 231                 .mode           = 0555,
 232                 .child          = debug_table,
 233         },
 234         {
 235                 .ctl_name       = CTL_DEV,
 236                 .procname       = "dev",
 237                 .mode           = 0555,
 238                 .child          = dev_table,
 239         },
 240 /*
 241  * NOTE: do not add new entries to this table unless you have read
 242  * Documentation/sysctl/ctl_unnumbered.txt
 243  */
 244         { .ctl_name = 0 }
 245 };
 246
 247 #ifdef CONFIG_SCHED_DEBUG
 248 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 249 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 250 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 251 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 252 #endif
 253
 254 static struct ctl_table kern_table[] = {
 255         {
 256                 .ctl_name       = CTL_UNNUMBERED,
 257                 .procname       = "sched_child_runs_first",
 258                 .data           = &sysctl_sched_child_runs_first,
 259                 .maxlen         = sizeof(unsigned int),
 260                 .mode           = 0644,
 261                 .proc_handler   = &proc_dointvec,
 262         },
 263 #ifdef CONFIG_SCHED_DEBUG
 264         {
 265                 .ctl_name       = CTL_UNNUMBERED,
 266                 .procname       = "sched_min_granularity_ns",
 267                 .data           = &sysctl_sched_min_granularity,
 268                 .maxlen         = sizeof(unsigned int),
 269                 .mode           = 0644,
 270                 .proc_handler   = &sched_nr_latency_handler,
 271                 .strategy       = &sysctl_intvec,
 272                 .extra1         = &min_sched_granularity_ns,
 273                 .extra2         = &max_sched_granularity_ns,
 274         },
 275         {
 276                 .ctl_name       = CTL_UNNUMBERED,
 277                 .procname       = "sched_latency_ns",
 278                 .data           = &sysctl_sched_latency,
 279                 .maxlen         = sizeof(unsigned int),
 280                 .mode           = 0644,
 281                 .proc_handler   = &sched_nr_latency_handler,
 282                 .strategy       = &sysctl_intvec,
 283                 .extra1         = &min_sched_granularity_ns,
 284                 .extra2         = &max_sched_granularity_ns,
 285         },
 286         {
 287                 .ctl_name       = CTL_UNNUMBERED,
 288                 .procname       = "sched_wakeup_granularity_ns",
 289                 .data           = &sysctl_sched_wakeup_granularity,
 290                 .maxlen         = sizeof(unsigned int),
 291                 .mode           = 0644,
 292                 .proc_handler   = &proc_dointvec_minmax,
 293                 .strategy       = &sysctl_intvec,
 294                 .extra1         = &min_wakeup_granularity_ns,
 295                 .extra2         = &max_wakeup_granularity_ns,
 296         },
 297         {
 298                 .ctl_name       = CTL_UNNUMBERED,
 299                 .procname       = "sched_shares_ratelimit",
 300                 .data           = &sysctl_sched_shares_ratelimit,
 301                 .maxlen         = sizeof(unsigned int),
 302                 .mode           = 0644,
 303                 .proc_handler   = &proc_dointvec,
 304         },
 305         {
 306                 .ctl_name       = CTL_UNNUMBERED,
 307                 .procname       = "sched_shares_thresh",
 308                 .data           = &sysctl_sched_shares_thresh,
 309                 .maxlen         = sizeof(unsigned int),
 310                 .mode           = 0644,
 311                 .proc_handler   = &proc_dointvec_minmax,
 312                 .strategy       = &sysctl_intvec,
 313                 .extra1         = &zero,
 314         },
 315         {
 316                 .ctl_name       = CTL_UNNUMBERED,
 317                 .procname       = "sched_features",
 318                 .data           = &sysctl_sched_features,
 319                 .maxlen         = sizeof(unsigned int),
 320                 .mode           = 0644,
 321                 .proc_handler   = &proc_dointvec,
 322         },
 323         {
 324                 .ctl_name       = CTL_UNNUMBERED,
 325                 .procname       = "sched_migration_cost",
 326                 .data           = &sysctl_sched_migration_cost,
 327                 .maxlen         = sizeof(unsigned int),
 328                 .mode           = 0644,
 329                 .proc_handler   = &proc_dointvec,
 330         },
 331         {
 332                 .ctl_name       = CTL_UNNUMBERED,
 333                 .procname       = "sched_nr_migrate",
 334                 .data           = &sysctl_sched_nr_migrate,
 335                 .maxlen         = sizeof(unsigned int),
 336                 .mode           = 0644,
 337                 .proc_handler   = &proc_dointvec,
 338         },
 339         {
 340                 .ctl_name       = CTL_UNNUMBERED,
 341                 .procname       = "sched_time_avg",
 342                 .data           = &sysctl_sched_time_avg,
 343                 .maxlen         = sizeof(unsigned int),
 344                 .mode           = 0644,
 345                 .proc_handler   = &proc_dointvec,
 346         },
 347         {
 348                 .ctl_name       = CTL_UNNUMBERED,
 349                 .procname       = "timer_migration",
 350                 .data           = &sysctl_timer_migration,
 351                 .maxlen         = sizeof(unsigned int),
 352                 .mode           = 0644,
 353                 .proc_handler   = &proc_dointvec_minmax,
 354                 .strategy       = &sysctl_intvec,
 355                 .extra1         = &zero,
 356                 .extra2         = &one,
 357         },
 358 #endif
 359         {
 360                 .ctl_name       = CTL_UNNUMBERED,
 361                 .procname       = "sched_rt_period_us",
 362                 .data           = &sysctl_sched_rt_period,
 363                 .maxlen         = sizeof(unsigned int),
 364                 .mode           = 0644,
 365                 .proc_handler   = &sched_rt_handler,
 366         },
 367         {
 368                 .ctl_name       = CTL_UNNUMBERED,
 369                 .procname       = "sched_rt_runtime_us",
 370                 .data           = &sysctl_sched_rt_runtime,
 371                 .maxlen         = sizeof(int),
 372                 .mode           = 0644,
 373                 .proc_handler   = &sched_rt_handler,
 374         },
 375         {
 376                 .ctl_name       = CTL_UNNUMBERED,
 377                 .procname       = "sched_compat_yield",
 378                 .data           = &sysctl_sched_compat_yield,
 379                 .maxlen         = sizeof(unsigned int),
 380                 .mode           = 0644,
 381                 .proc_handler   = &proc_dointvec,
 382         },
 383 #ifdef CONFIG_PROVE_LOCKING
 384         {
 385                 .ctl_name       = CTL_UNNUMBERED,
 386                 .procname       = "prove_locking",
 387                 .data           = &prove_locking,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = &proc_dointvec,
 391         },
 392 #endif
 393 #ifdef CONFIG_LOCK_STAT
 394         {
 395                 .ctl_name       = CTL_UNNUMBERED,
 396                 .procname       = "lock_stat",
 397                 .data           = &lock_stat,
 398                 .maxlen         = sizeof(int),
 399                 .mode           = 0644,
 400                 .proc_handler   = &proc_dointvec,
 401         },
 402 #endif
 403         {
 404                 .ctl_name       = KERN_PANIC,
 405                 .procname       = "panic",
 406                 .data           = &panic_timeout,
 407                 .maxlen         = sizeof(int),
 408                 .mode           = 0644,
 409                 .proc_handler   = &proc_dointvec,
 410         },
 411         {
 412                 .ctl_name       = KERN_CORE_USES_PID,
 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                 .ctl_name       = KERN_CORE_PATTERN,
 421                 .procname       = "core_pattern",
 422                 .data           = core_pattern,
 423                 .maxlen         = CORENAME_MAX_SIZE,
 424                 .mode           = 0644,
 425                 .proc_handler   = &proc_dostring,
 426                 .strategy       = &sysctl_string,
 427         },
 428         {
 429                 .ctl_name       = CTL_UNNUMBERED,
 430                 .procname       = "core_pipe_limit",
 431                 .data           = &core_pipe_limit,
 432                 .maxlen         = sizeof(unsigned int),
 433                 .mode           = 0644,
 434                 .proc_handler   = &proc_dointvec,
 435         },
 436 #ifdef CONFIG_PROC_SYSCTL
 437         {
 438                 .procname       = "tainted",
 439                 .maxlen         = sizeof(long),
 440                 .mode           = 0644,
 441                 .proc_handler   = &proc_taint,
 442         },
 443 #endif
 444 #ifdef CONFIG_LATENCYTOP
 445         {
 446                 .procname       = "latencytop",
 447                 .data           = &latencytop_enabled,
 448                 .maxlen         = sizeof(int),
 449                 .mode           = 0644,
 450                 .proc_handler   = &proc_dointvec,
 451         },
 452 #endif
 453 #ifdef CONFIG_BLK_DEV_INITRD
 454         {
 455                 .ctl_name       = KERN_REALROOTDEV,
 456                 .procname       = "real-root-dev",
 457                 .data           = &real_root_dev,
 458                 .maxlen         = sizeof(int),
 459                 .mode           = 0644,
 460                 .proc_handler   = &proc_dointvec,
 461         },
 462 #endif
 463         {
 464                 .ctl_name       = CTL_UNNUMBERED,
 465                 .procname       = "print-fatal-signals",
 466                 .data           = &print_fatal_signals,
 467                 .maxlen         = sizeof(int),
 468                 .mode           = 0644,
 469                 .proc_handler   = &proc_dointvec,
 470         },
 471 #ifdef CONFIG_SPARC
 472         {
 473                 .ctl_name       = KERN_SPARC_REBOOT,
 474                 .procname       = "reboot-cmd",
 475                 .data           = reboot_command,
 476                 .maxlen         = 256,
 477                 .mode           = 0644,
 478                 .proc_handler   = &proc_dostring,
 479                 .strategy       = &sysctl_string,
 480         },
 481         {
 482                 .ctl_name       = KERN_SPARC_STOP_A,
 483                 .procname       = "stop-a",
 484                 .data           = &stop_a_enabled,
 485                 .maxlen         = sizeof (int),
 486                 .mode           = 0644,
 487                 .proc_handler   = &proc_dointvec,
 488         },
 489         {
 490                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 491                 .procname       = "scons-poweroff",
 492                 .data           = &scons_pwroff,
 493                 .maxlen         = sizeof (int),
 494                 .mode           = 0644,
 495                 .proc_handler   = &proc_dointvec,
 496         },
 497 #endif
 498 #ifdef CONFIG_SPARC64
 499         {
 500                 .ctl_name       = CTL_UNNUMBERED,
 501                 .procname       = "tsb-ratio",
 502                 .data           = &sysctl_tsb_ratio,
 503                 .maxlen         = sizeof (int),
 504                 .mode           = 0644,
 505                 .proc_handler   = &proc_dointvec,
 506         },
 507 #endif
 508 #ifdef __hppa__
 509         {
 510                 .ctl_name       = KERN_HPPA_PWRSW,
 511                 .procname       = "soft-power",
 512                 .data           = &pwrsw_enabled,
 513                 .maxlen         = sizeof (int),
 514                 .mode           = 0644,
 515                 .proc_handler   = &proc_dointvec,
 516         },
 517         {
 518                 .ctl_name       = KERN_HPPA_UNALIGNED,
 519                 .procname       = "unaligned-trap",
 520                 .data           = &unaligned_enabled,
 521                 .maxlen         = sizeof (int),
 522                 .mode           = 0644,
 523                 .proc_handler   = &proc_dointvec,
 524         },
 525 #endif
 526         {
 527                 .ctl_name       = KERN_CTLALTDEL,
 528                 .procname       = "ctrl-alt-del",
 529                 .data           = &C_A_D,
 530                 .maxlen         = sizeof(int),
 531                 .mode           = 0644,
 532                 .proc_handler   = &proc_dointvec,
 533         },
 534 #ifdef CONFIG_FUNCTION_TRACER
 535         {
 536                 .ctl_name       = CTL_UNNUMBERED,
 537                 .procname       = "ftrace_enabled",
 538                 .data           = &ftrace_enabled,
 539                 .maxlen         = sizeof(int),
 540                 .mode           = 0644,
 541                 .proc_handler   = &ftrace_enable_sysctl,
 542         },
 543 #endif
 544 #ifdef CONFIG_STACK_TRACER
 545         {
 546                 .ctl_name       = CTL_UNNUMBERED,
 547                 .procname       = "stack_tracer_enabled",
 548                 .data           = &stack_tracer_enabled,
 549                 .maxlen         = sizeof(int),
 550                 .mode           = 0644,
 551                 .proc_handler   = &stack_trace_sysctl,
 552         },
 553 #endif
 554 #ifdef CONFIG_TRACING
 555         {
 556                 .ctl_name       = CTL_UNNUMBERED,
 557                 .procname       = "ftrace_dump_on_oops",
 558                 .data           = &ftrace_dump_on_oops,
 559                 .maxlen         = sizeof(int),
 560                 .mode           = 0644,
 561                 .proc_handler   = &proc_dointvec,
 562         },
 563 #endif
 564 #ifdef CONFIG_MODULES
 565         {
 566                 .ctl_name       = KERN_MODPROBE,
 567                 .procname       = "modprobe",
 568                 .data           = &modprobe_path,
 569                 .maxlen         = KMOD_PATH_LEN,
 570                 .mode           = 0644,
 571                 .proc_handler   = &proc_dostring,
 572                 .strategy       = &sysctl_string,
 573         },
 574         {
 575                 .ctl_name       = CTL_UNNUMBERED,
 576                 .procname       = "modules_disabled",
 577                 .data           = &modules_disabled,
 578                 .maxlen         = sizeof(int),
 579                 .mode           = 0644,
 580                 /* only handle a transition from default "0" to "1" */
 581                 .proc_handler   = &proc_dointvec_minmax,
 582                 .extra1         = &one,
 583                 .extra2         = &one,
 584         },
 585 #endif
 586 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 587         {
 588                 .ctl_name       = KERN_HOTPLUG,
 589                 .procname       = "hotplug",
 590                 .data           = &uevent_helper,
 591                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 592                 .mode           = 0644,
 593                 .proc_handler   = &proc_dostring,
 594                 .strategy       = &sysctl_string,
 595         },
 596 #endif
 597 #ifdef CONFIG_CHR_DEV_SG
 598         {
 599                 .ctl_name       = KERN_SG_BIG_BUFF,
 600                 .procname       = "sg-big-buff",
 601                 .data           = &sg_big_buff,
 602                 .maxlen         = sizeof (int),
 603                 .mode           = 0444,
 604                 .proc_handler   = &proc_dointvec,
 605         },
 606 #endif
 607 #ifdef CONFIG_BSD_PROCESS_ACCT
 608         {
 609                 .ctl_name       = KERN_ACCT,
 610                 .procname       = "acct",
 611                 .data           = &acct_parm,
 612                 .maxlen         = 3*sizeof(int),
 613                 .mode           = 0644,
 614                 .proc_handler   = &proc_dointvec,
 615         },
 616 #endif
 617 #ifdef CONFIG_MAGIC_SYSRQ
 618         {
 619                 .ctl_name       = KERN_SYSRQ,
 620                 .procname       = "sysrq",
 621                 .data           = &__sysrq_enabled,
 622                 .maxlen         = sizeof (int),
 623                 .mode           = 0644,
 624                 .proc_handler   = &proc_dointvec,
 625         },
 626 #endif
 627 #ifdef CONFIG_PROC_SYSCTL
 628         {
 629                 .procname       = "cad_pid",
 630                 .data           = NULL,
 631                 .maxlen         = sizeof (int),
 632                 .mode           = 0600,
 633                 .proc_handler   = &proc_do_cad_pid,
 634         },
 635 #endif
 636         {
 637                 .ctl_name       = KERN_MAX_THREADS,
 638                 .procname       = "threads-max",
 639                 .data           = &max_threads,
 640                 .maxlen         = sizeof(int),
 641                 .mode           = 0644,
 642                 .proc_handler   = &proc_dointvec,
 643         },
 644         {
 645                 .ctl_name       = KERN_RANDOM,
 646                 .procname       = "random",
 647                 .mode           = 0555,
 648                 .child          = random_table,
 649         },
 650         {
 651                 .ctl_name       = KERN_OVERFLOWUID,
 652                 .procname       = "overflowuid",
 653                 .data           = &overflowuid,
 654                 .maxlen         = sizeof(int),
 655                 .mode           = 0644,
 656                 .proc_handler   = &proc_dointvec_minmax,
 657                 .strategy       = &sysctl_intvec,
 658                 .extra1         = &minolduid,
 659                 .extra2         = &maxolduid,
 660         },
 661         {
 662                 .ctl_name       = KERN_OVERFLOWGID,
 663                 .procname       = "overflowgid",
 664                 .data           = &overflowgid,
 665                 .maxlen         = sizeof(int),
 666                 .mode           = 0644,
 667                 .proc_handler   = &proc_dointvec_minmax,
 668                 .strategy       = &sysctl_intvec,
 669                 .extra1         = &minolduid,
 670                 .extra2         = &maxolduid,
 671         },
 672 #ifdef CONFIG_S390
 673 #ifdef CONFIG_MATHEMU
 674         {
 675                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 676                 .procname       = "ieee_emulation_warnings",
 677                 .data           = &sysctl_ieee_emulation_warnings,
 678                 .maxlen         = sizeof(int),
 679                 .mode           = 0644,
 680                 .proc_handler   = &proc_dointvec,
 681         },
 682 #endif
 683         {
 684                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 685                 .procname       = "userprocess_debug",
 686                 .data           = &sysctl_userprocess_debug,
 687                 .maxlen         = sizeof(int),
 688                 .mode           = 0644,
 689                 .proc_handler   = &proc_dointvec,
 690         },
 691 #endif
 692         {
 693                 .ctl_name       = KERN_PIDMAX,
 694                 .procname       = "pid_max",
 695                 .data           = &pid_max,
 696                 .maxlen         = sizeof (int),
 697                 .mode           = 0644,
 698                 .proc_handler   = &proc_dointvec_minmax,
 699                 .strategy       = sysctl_intvec,
 700                 .extra1         = &pid_max_min,
 701                 .extra2         = &pid_max_max,
 702         },
 703         {
 704                 .ctl_name       = KERN_PANIC_ON_OOPS,
 705                 .procname       = "panic_on_oops",
 706                 .data           = &panic_on_oops,
 707                 .maxlen         = sizeof(int),
 708                 .mode           = 0644,
 709                 .proc_handler   = &proc_dointvec,
 710         },
 711 #if defined CONFIG_PRINTK
 712         {
 713                 .ctl_name       = KERN_PRINTK,
 714                 .procname       = "printk",
 715                 .data           = &console_loglevel,
 716                 .maxlen         = 4*sizeof(int),
 717                 .mode           = 0644,
 718                 .proc_handler   = &proc_dointvec,
 719         },
 720         {
 721                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 722                 .procname       = "printk_ratelimit",
 723                 .data           = &printk_ratelimit_state.interval,
 724                 .maxlen         = sizeof(int),
 725                 .mode           = 0644,
 726                 .proc_handler   = &proc_dointvec_jiffies,
 727                 .strategy       = &sysctl_jiffies,
 728         },
 729         {
 730                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 731                 .procname       = "printk_ratelimit_burst",
 732                 .data           = &printk_ratelimit_state.burst,
 733                 .maxlen         = sizeof(int),
 734                 .mode           = 0644,
 735                 .proc_handler   = &proc_dointvec,
 736         },
 737         {
 738                 .ctl_name       = CTL_UNNUMBERED,
 739                 .procname       = "printk_delay",
 740                 .data           = &printk_delay_msec,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0644,
 743                 .proc_handler   = &proc_dointvec_minmax,
 744                 .strategy       = &sysctl_intvec,
 745                 .extra1         = &zero,
 746                 .extra2         = &ten_thousand,
 747         },
 748 #endif
 749         {
 750                 .ctl_name       = KERN_NGROUPS_MAX,
 751                 .procname       = "ngroups_max",
 752                 .data           = &ngroups_max,
 753                 .maxlen         = sizeof (int),
 754                 .mode           = 0444,
 755                 .proc_handler   = &proc_dointvec,
 756         },
 757 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 758         {
 759                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 760                 .procname       = "unknown_nmi_panic",
 761                 .data           = &unknown_nmi_panic,
 762                 .maxlen         = sizeof (int),
 763                 .mode           = 0644,
 764                 .proc_handler   = &proc_dointvec,
 765         },
 766         {
 767                 .procname       = "nmi_watchdog",
 768                 .data           = &nmi_watchdog_enabled,
 769                 .maxlen         = sizeof (int),
 770                 .mode           = 0644,
 771                 .proc_handler   = &proc_nmi_enabled,
 772         },
 773 #endif
 774 #if defined(CONFIG_X86)
 775         {
 776                 .ctl_name       = KERN_PANIC_ON_NMI,
 777                 .procname       = "panic_on_unrecovered_nmi",
 778                 .data           = &panic_on_unrecovered_nmi,
 779                 .maxlen         = sizeof(int),
 780                 .mode           = 0644,
 781                 .proc_handler   = &proc_dointvec,
 782         },
 783         {
 784                 .ctl_name       = CTL_UNNUMBERED,
 785                 .procname       = "panic_on_io_nmi",
 786                 .data           = &panic_on_io_nmi,
 787                 .maxlen         = sizeof(int),
 788                 .mode           = 0644,
 789                 .proc_handler   = &proc_dointvec,
 790         },
 791         {
 792                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 793                 .procname       = "bootloader_type",
 794                 .data           = &bootloader_type,
 795                 .maxlen         = sizeof (int),
 796                 .mode           = 0444,
 797                 .proc_handler   = &proc_dointvec,
 798         },
 799         {
 800                 .ctl_name       = CTL_UNNUMBERED,
 801                 .procname       = "bootloader_version",
 802                 .data           = &bootloader_version,
 803                 .maxlen         = sizeof (int),
 804                 .mode           = 0444,
 805                 .proc_handler   = &proc_dointvec,
 806         },
 807         {
 808                 .ctl_name       = CTL_UNNUMBERED,
 809                 .procname       = "kstack_depth_to_print",
 810                 .data           = &kstack_depth_to_print,
 811                 .maxlen         = sizeof(int),
 812                 .mode           = 0644,
 813                 .proc_handler   = &proc_dointvec,
 814         },
 815         {
 816                 .ctl_name       = CTL_UNNUMBERED,
 817                 .procname       = "io_delay_type",
 818                 .data           = &io_delay_type,
 819                 .maxlen         = sizeof(int),
 820                 .mode           = 0644,
 821                 .proc_handler   = &proc_dointvec,
 822         },
 823 #endif
 824 #if defined(CONFIG_MMU)
 825         {
 826                 .ctl_name       = KERN_RANDOMIZE,
 827                 .procname       = "randomize_va_space",
 828                 .data           = &randomize_va_space,
 829                 .maxlen         = sizeof(int),
 830                 .mode           = 0644,
 831                 .proc_handler   = &proc_dointvec,
 832         },
 833 #endif
 834 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 835         {
 836                 .ctl_name       = KERN_SPIN_RETRY,
 837                 .procname       = "spin_retry",
 838                 .data           = &spin_retry,
 839                 .maxlen         = sizeof (int),
 840                 .mode           = 0644,
 841                 .proc_handler   = &proc_dointvec,
 842         },
 843 #endif
 844 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 845         {
 846                 .procname       = "acpi_video_flags",
 847                 .data           = &acpi_realmode_flags,
 848                 .maxlen         = sizeof (unsigned long),
 849                 .mode           = 0644,
 850                 .proc_handler   = &proc_doulongvec_minmax,
 851         },
 852 #endif
 853 #ifdef CONFIG_IA64
 854         {
 855                 .ctl_name       = KERN_IA64_UNALIGNED,
 856                 .procname       = "ignore-unaligned-usertrap",
 857                 .data           = &no_unaligned_warning,
 858                 .maxlen         = sizeof (int),
 859                 .mode           = 0644,
 860                 .proc_handler   = &proc_dointvec,
 861         },
 862         {
 863                 .ctl_name       = CTL_UNNUMBERED,
 864                 .procname       = "unaligned-dump-stack",
 865                 .data           = &unaligned_dump_stack,
 866                 .maxlen         = sizeof (int),
 867                 .mode           = 0644,
 868                 .proc_handler   = &proc_dointvec,
 869         },
 870 #endif
 871 #ifdef CONFIG_DETECT_SOFTLOCKUP
 872         {
 873                 .ctl_name       = CTL_UNNUMBERED,
 874                 .procname       = "softlockup_panic",
 875                 .data           = &softlockup_panic,
 876                 .maxlen         = sizeof(int),
 877                 .mode           = 0644,
 878                 .proc_handler   = &proc_dointvec_minmax,
 879                 .strategy       = &sysctl_intvec,
 880                 .extra1         = &zero,
 881                 .extra2         = &one,
 882         },
 883         {
 884                 .ctl_name       = CTL_UNNUMBERED,
 885                 .procname       = "softlockup_thresh",
 886                 .data           = &softlockup_thresh,
 887                 .maxlen         = sizeof(int),
 888                 .mode           = 0644,
 889                 .proc_handler   = &proc_dosoftlockup_thresh,
 890                 .strategy       = &sysctl_intvec,
 891                 .extra1         = &neg_one,
 892                 .extra2         = &sixty,
 893         },
 894 #endif
 895 #ifdef CONFIG_DETECT_HUNG_TASK
 896         {
 897                 .ctl_name       = CTL_UNNUMBERED,
 898                 .procname       = "hung_task_panic",
 899                 .data           = &sysctl_hung_task_panic,
 900                 .maxlen         = sizeof(int),
 901                 .mode           = 0644,
 902                 .proc_handler   = &proc_dointvec_minmax,
 903                 .strategy       = &sysctl_intvec,
 904                 .extra1         = &zero,
 905                 .extra2         = &one,
 906         },
 907         {
 908                 .ctl_name       = CTL_UNNUMBERED,
 909                 .procname       = "hung_task_check_count",
 910                 .data           = &sysctl_hung_task_check_count,
 911                 .maxlen         = sizeof(unsigned long),
 912                 .mode           = 0644,
 913                 .proc_handler   = &proc_doulongvec_minmax,
 914                 .strategy       = &sysctl_intvec,
 915         },
 916         {
 917                 .ctl_name       = CTL_UNNUMBERED,
 918                 .procname       = "hung_task_timeout_secs",
 919                 .data           = &sysctl_hung_task_timeout_secs,
 920                 .maxlen         = sizeof(unsigned long),
 921                 .mode           = 0644,
 922                 .proc_handler   = &proc_dohung_task_timeout_secs,
 923                 .strategy       = &sysctl_intvec,
 924         },
 925         {
 926                 .ctl_name       = CTL_UNNUMBERED,
 927                 .procname       = "hung_task_warnings",
 928                 .data           = &sysctl_hung_task_warnings,
 929                 .maxlen         = sizeof(unsigned long),
 930                 .mode           = 0644,
 931                 .proc_handler   = &proc_doulongvec_minmax,
 932                 .strategy       = &sysctl_intvec,
 933         },
 934 #endif
 935 #ifdef CONFIG_COMPAT
 936         {
 937                 .ctl_name       = KERN_COMPAT_LOG,
 938                 .procname       = "compat-log",
 939                 .data           = &compat_log,
 940                 .maxlen         = sizeof (int),
 941                 .mode           = 0644,
 942                 .proc_handler   = &proc_dointvec,
 943         },
 944 #endif
 945 #ifdef CONFIG_RT_MUTEXES
 946         {
 947                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 948                 .procname       = "max_lock_depth",
 949                 .data           = &max_lock_depth,
 950                 .maxlen         = sizeof(int),
 951                 .mode           = 0644,
 952                 .proc_handler   = &proc_dointvec,
 953         },
 954 #endif
 955         {
 956                 .ctl_name       = CTL_UNNUMBERED,
 957                 .procname       = "poweroff_cmd",
 958                 .data           = &poweroff_cmd,
 959                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 960                 .mode           = 0644,
 961                 .proc_handler   = &proc_dostring,
 962                 .strategy       = &sysctl_string,
 963         },
 964 #ifdef CONFIG_KEYS
 965         {
 966                 .ctl_name       = CTL_UNNUMBERED,
 967                 .procname       = "keys",
 968                 .mode           = 0555,
 969                 .child          = key_sysctls,
 970         },
 971 #endif
 972 #ifdef CONFIG_RCU_TORTURE_TEST
 973         {
 974                 .ctl_name       = CTL_UNNUMBERED,
 975                 .procname       = "rcutorture_runnable",
 976                 .data           = &rcutorture_runnable,
 977                 .maxlen         = sizeof(int),
 978                 .mode           = 0644,
 979                 .proc_handler   = &proc_dointvec,
 980         },
 981 #endif
 982 #ifdef CONFIG_SLOW_WORK
 983         {
 984                 .ctl_name       = CTL_UNNUMBERED,
 985                 .procname       = "slow-work",
 986                 .mode           = 0555,
 987                 .child          = slow_work_sysctls,
 988         },
 989 #endif
 990 #ifdef CONFIG_PERF_EVENTS
 991         {
 992                 .ctl_name       = CTL_UNNUMBERED,
 993                 .procname       = "perf_event_paranoid",
 994                 .data           = &sysctl_perf_event_paranoid,
 995                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 996                 .mode           = 0644,
 997                 .proc_handler   = &proc_dointvec,
 998         },
 999         {
1000                 .ctl_name       = CTL_UNNUMBERED,
1001                 .procname       = "perf_event_mlock_kb",
1002                 .data           = &sysctl_perf_event_mlock,
1003                 .maxlen         = sizeof(sysctl_perf_event_mlock),
1004                 .mode           = 0644,
1005                 .proc_handler   = &proc_dointvec,
1006         },
1007         {
1008                 .ctl_name       = CTL_UNNUMBERED,
1009                 .procname       = "perf_event_max_sample_rate",
1010                 .data           = &sysctl_perf_event_sample_rate,
1011                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
1012                 .mode           = 0644,
1013                 .proc_handler   = &proc_dointvec,
1014         },
1015 #endif
1016 #ifdef CONFIG_KMEMCHECK
1017         {
1018                 .ctl_name       = CTL_UNNUMBERED,
1019                 .procname       = "kmemcheck",
1020                 .data           = &kmemcheck_enabled,
1021                 .maxlen         = sizeof(int),
1022                 .mode           = 0644,
1023                 .proc_handler   = &proc_dointvec,
1024         },
1025 #endif
1026 #ifdef CONFIG_BLOCK
1027         {
1028                 .ctl_name       = CTL_UNNUMBERED,
1029                 .procname       = "blk_iopoll",
1030                 .data           = &blk_iopoll_enabled,
1031                 .maxlen         = sizeof(int),
1032                 .mode           = 0644,
1033                 .proc_handler   = &proc_dointvec,
1034         },
1035 #endif
1036 /*
1037  * NOTE: do not add new entries to this table unless you have read
1038  * Documentation/sysctl/ctl_unnumbered.txt
1039  */
1040         { .ctl_name = 0 }
1041 };
1042
1043 static struct ctl_table vm_table[] = {
1044         {
1045                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
1046                 .procname       = "overcommit_memory",
1047                 .data           = &sysctl_overcommit_memory,
1048                 .maxlen         = sizeof(sysctl_overcommit_memory),
1049                 .mode           = 0644,
1050                 .proc_handler   = &proc_dointvec,
1051         },
1052         {
1053                 .ctl_name       = VM_PANIC_ON_OOM,
1054                 .procname       = "panic_on_oom",
1055                 .data           = &sysctl_panic_on_oom,
1056                 .maxlen         = sizeof(sysctl_panic_on_oom),
1057                 .mode           = 0644,
1058                 .proc_handler   = &proc_dointvec,
1059         },
1060         {
1061                 .ctl_name       = CTL_UNNUMBERED,
1062                 .procname       = "oom_kill_allocating_task",
1063                 .data           = &sysctl_oom_kill_allocating_task,
1064                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1065                 .mode           = 0644,
1066                 .proc_handler   = &proc_dointvec,
1067         },
1068         {
1069                 .ctl_name       = CTL_UNNUMBERED,
1070                 .procname       = "oom_dump_tasks",
1071                 .data           = &sysctl_oom_dump_tasks,
1072                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1073                 .mode           = 0644,
1074                 .proc_handler   = &proc_dointvec,
1075         },
1076         {
1077                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1078                 .procname       = "overcommit_ratio",
1079                 .data           = &sysctl_overcommit_ratio,
1080                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1081                 .mode           = 0644,
1082                 .proc_handler   = &proc_dointvec,
1083         },
1084         {
1085                 .ctl_name       = VM_PAGE_CLUSTER,
1086                 .procname       = "page-cluster",
1087                 .data           = &page_cluster,
1088                 .maxlen         = sizeof(int),
1089                 .mode           = 0644,
1090                 .proc_handler   = &proc_dointvec,
1091         },
1092         {
1093                 .ctl_name       = VM_DIRTY_BACKGROUND,
1094                 .procname       = "dirty_background_ratio",
1095                 .data           = &dirty_background_ratio,
1096                 .maxlen         = sizeof(dirty_background_ratio),
1097                 .mode           = 0644,
1098                 .proc_handler   = &dirty_background_ratio_handler,
1099                 .strategy       = &sysctl_intvec,
1100                 .extra1         = &zero,
1101                 .extra2         = &one_hundred,
1102         },
1103         {
1104                 .ctl_name       = CTL_UNNUMBERED,
1105                 .procname       = "dirty_background_bytes",
1106                 .data           = &dirty_background_bytes,
1107                 .maxlen         = sizeof(dirty_background_bytes),
1108                 .mode           = 0644,
1109                 .proc_handler   = &dirty_background_bytes_handler,
1110                 .strategy       = &sysctl_intvec,
1111                 .extra1         = &one_ul,
1112         },
1113         {
1114                 .ctl_name       = VM_DIRTY_RATIO,
1115                 .procname       = "dirty_ratio",
1116                 .data           = &vm_dirty_ratio,
1117                 .maxlen         = sizeof(vm_dirty_ratio),
1118                 .mode           = 0644,
1119                 .proc_handler   = &dirty_ratio_handler,
1120                 .strategy       = &sysctl_intvec,
1121                 .extra1         = &zero,
1122                 .extra2         = &one_hundred,
1123         },
1124         {
1125                 .ctl_name       = CTL_UNNUMBERED,
1126                 .procname       = "dirty_bytes",
1127                 .data           = &vm_dirty_bytes,
1128                 .maxlen         = sizeof(vm_dirty_bytes),
1129                 .mode           = 0644,
1130                 .proc_handler   = &dirty_bytes_handler,
1131                 .strategy       = &sysctl_intvec,
1132                 .extra1         = &dirty_bytes_min,
1133         },
1134         {
1135                 .procname       = "dirty_writeback_centisecs",
1136                 .data           = &dirty_writeback_interval,
1137                 .maxlen         = sizeof(dirty_writeback_interval),
1138                 .mode           = 0644,
1139                 .proc_handler   = &dirty_writeback_centisecs_handler,
1140         },
1141         {
1142                 .procname       = "dirty_expire_centisecs",
1143                 .data           = &dirty_expire_interval,
1144                 .maxlen         = sizeof(dirty_expire_interval),
1145                 .mode           = 0644,
1146                 .proc_handler   = &proc_dointvec,
1147         },
1148         {
1149                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1150                 .procname       = "nr_pdflush_threads",
1151                 .data           = &nr_pdflush_threads,
1152                 .maxlen         = sizeof nr_pdflush_threads,
1153                 .mode           = 0444 /* read-only*/,
1154                 .proc_handler   = &proc_dointvec,
1155         },
1156         {
1157                 .ctl_name       = VM_SWAPPINESS,
1158                 .procname       = "swappiness",
1159                 .data           = &vm_swappiness,
1160                 .maxlen         = sizeof(vm_swappiness),
1161                 .mode           = 0644,
1162                 .proc_handler   = &proc_dointvec_minmax,
1163                 .strategy       = &sysctl_intvec,
1164                 .extra1         = &zero,
1165                 .extra2         = &one_hundred,
1166         },
1167 #ifdef CONFIG_HUGETLB_PAGE
1168          {
1169                 .procname       = "nr_hugepages",
1170                 .data           = NULL,
1171                 .maxlen         = sizeof(unsigned long),
1172                 .mode           = 0644,
1173                 .proc_handler   = &hugetlb_sysctl_handler,
1174                 .extra1         = (void *)&hugetlb_zero,
1175                 .extra2         = (void *)&hugetlb_infinity,
1176          },
1177          {
1178                 .ctl_name       = VM_HUGETLB_GROUP,
1179                 .procname       = "hugetlb_shm_group",
1180                 .data           = &sysctl_hugetlb_shm_group,
1181                 .maxlen         = sizeof(gid_t),
1182                 .mode           = 0644,
1183                 .proc_handler   = &proc_dointvec,
1184          },
1185          {
1186                 .ctl_name       = CTL_UNNUMBERED,
1187                 .procname       = "hugepages_treat_as_movable",
1188                 .data           = &hugepages_treat_as_movable,
1189                 .maxlen         = sizeof(int),
1190                 .mode           = 0644,
1191                 .proc_handler   = &hugetlb_treat_movable_handler,
1192         },
1193         {
1194                 .ctl_name       = CTL_UNNUMBERED,
1195                 .procname       = "nr_overcommit_hugepages",
1196                 .data           = NULL,
1197                 .maxlen         = sizeof(unsigned long),
1198                 .mode           = 0644,
1199                 .proc_handler   = &hugetlb_overcommit_handler,
1200                 .extra1         = (void *)&hugetlb_zero,
1201                 .extra2         = (void *)&hugetlb_infinity,
1202         },
1203 #endif
1204         {
1205                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1206                 .procname       = "lowmem_reserve_ratio",
1207                 .data           = &sysctl_lowmem_reserve_ratio,
1208                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1209                 .mode           = 0644,
1210                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1211                 .strategy       = &sysctl_intvec,
1212         },
1213         {
1214                 .ctl_name       = VM_DROP_PAGECACHE,
1215                 .procname       = "drop_caches",
1216                 .data           = &sysctl_drop_caches,
1217                 .maxlen         = sizeof(int),
1218                 .mode           = 0644,
1219                 .proc_handler   = drop_caches_sysctl_handler,
1220                 .strategy       = &sysctl_intvec,
1221         },
1222         {
1223                 .ctl_name       = VM_MIN_FREE_KBYTES,
1224                 .procname       = "min_free_kbytes",
1225                 .data           = &min_free_kbytes,
1226                 .maxlen         = sizeof(min_free_kbytes),
1227                 .mode           = 0644,
1228                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1229                 .strategy       = &sysctl_intvec,
1230                 .extra1         = &zero,
1231         },
1232         {
1233                 .ctl_name       = CTL_UNNUMBERED,
1234                 .procname       = "min_free_order_shift",
1235                 .data           = &min_free_order_shift,
1236                 .maxlen         = sizeof(min_free_order_shift),
1237                 .mode           = 0644,
1238                 .proc_handler   = &proc_dointvec
1239         },
1240         {
1241                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1242                 .procname       = "percpu_pagelist_fraction",
1243                 .data           = &percpu_pagelist_fraction,
1244                 .maxlen         = sizeof(percpu_pagelist_fraction),
1245                 .mode           = 0644,
1246                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1247                 .strategy       = &sysctl_intvec,
1248                 .extra1         = &min_percpu_pagelist_fract,
1249         },
1250 #ifdef CONFIG_MMU
1251         {
1252                 .ctl_name       = VM_MAX_MAP_COUNT,
1253                 .procname       = "max_map_count",
1254                 .data           = &sysctl_max_map_count,
1255                 .maxlen         = sizeof(sysctl_max_map_count),
1256                 .mode           = 0644,
1257                 .proc_handler   = &proc_dointvec
1258         },
1259 #else
1260         {
1261                 .ctl_name       = CTL_UNNUMBERED,
1262                 .procname       = "nr_trim_pages",
1263                 .data           = &sysctl_nr_trim_pages,
1264                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1265                 .mode           = 0644,
1266                 .proc_handler   = &proc_dointvec_minmax,
1267                 .strategy       = &sysctl_intvec,
1268                 .extra1         = &zero,
1269         },
1270 #endif
1271         {
1272                 .ctl_name       = VM_LAPTOP_MODE,
1273                 .procname       = "laptop_mode",
1274                 .data           = &laptop_mode,
1275                 .maxlen         = sizeof(laptop_mode),
1276                 .mode           = 0644,
1277                 .proc_handler   = &proc_dointvec_jiffies,
1278                 .strategy       = &sysctl_jiffies,
1279         },
1280         {
1281                 .ctl_name       = VM_BLOCK_DUMP,
1282                 .procname       = "block_dump",
1283                 .data           = &block_dump,
1284                 .maxlen         = sizeof(block_dump),
1285                 .mode           = 0644,
1286                 .proc_handler   = &proc_dointvec,
1287                 .strategy       = &sysctl_intvec,
1288                 .extra1         = &zero,
1289         },
1290         {
1291                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1292                 .procname       = "vfs_cache_pressure",
1293                 .data           = &sysctl_vfs_cache_pressure,
1294                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1295                 .mode           = 0644,
1296                 .proc_handler   = &proc_dointvec,
1297                 .strategy       = &sysctl_intvec,
1298                 .extra1         = &zero,
1299         },
1300 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1301         {
1302                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1303                 .procname       = "legacy_va_layout",
1304                 .data           = &sysctl_legacy_va_layout,
1305                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1306                 .mode           = 0644,
1307                 .proc_handler   = &proc_dointvec,
1308                 .strategy       = &sysctl_intvec,
1309                 .extra1         = &zero,
1310         },
1311 #endif
1312 #ifdef CONFIG_NUMA
1313         {
1314                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1315                 .procname       = "zone_reclaim_mode",
1316                 .data           = &zone_reclaim_mode,
1317                 .maxlen         = sizeof(zone_reclaim_mode),
1318                 .mode           = 0644,
1319                 .proc_handler   = &proc_dointvec,
1320                 .strategy       = &sysctl_intvec,
1321                 .extra1         = &zero,
1322         },
1323         {
1324                 .ctl_name       = VM_MIN_UNMAPPED,
1325                 .procname       = "min_unmapped_ratio",
1326                 .data           = &sysctl_min_unmapped_ratio,
1327                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1328                 .mode           = 0644,
1329                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1330                 .strategy       = &sysctl_intvec,
1331                 .extra1         = &zero,
1332                 .extra2         = &one_hundred,
1333         },
1334         {
1335                 .ctl_name       = VM_MIN_SLAB,
1336                 .procname       = "min_slab_ratio",
1337                 .data           = &sysctl_min_slab_ratio,
1338                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1339                 .mode           = 0644,
1340                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1341                 .strategy       = &sysctl_intvec,
1342                 .extra1         = &zero,
1343                 .extra2         = &one_hundred,
1344         },
1345 #endif
1346 #ifdef CONFIG_SMP
1347         {
1348                 .ctl_name       = CTL_UNNUMBERED,
1349                 .procname       = "stat_interval",
1350                 .data           = &sysctl_stat_interval,
1351                 .maxlen         = sizeof(sysctl_stat_interval),
1352                 .mode           = 0644,
1353                 .proc_handler   = &proc_dointvec_jiffies,
1354                 .strategy       = &sysctl_jiffies,
1355         },
1356 #endif
1357 #ifdef CONFIG_MMU
1358         {
1359                 .ctl_name       = CTL_UNNUMBERED,
1360                 .procname       = "mmap_min_addr",
1361                 .data           = &dac_mmap_min_addr,
1362                 .maxlen         = sizeof(unsigned long),
1363                 .mode           = 0644,
1364                 .proc_handler   = &mmap_min_addr_handler,
1365         },
1366 #endif
1367 #ifdef CONFIG_NUMA
1368         {
1369                 .ctl_name       = CTL_UNNUMBERED,
1370                 .procname       = "numa_zonelist_order",
1371                 .data           = &numa_zonelist_order,
1372                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1373                 .mode           = 0644,
1374                 .proc_handler   = &numa_zonelist_order_handler,
1375                 .strategy       = &sysctl_string,
1376         },
1377 #endif
1378 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1379    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1380         {
1381                 .ctl_name       = VM_VDSO_ENABLED,
1382                 .procname       = "vdso_enabled",
1383                 .data           = &vdso_enabled,
1384                 .maxlen         = sizeof(vdso_enabled),
1385                 .mode           = 0644,
1386                 .proc_handler   = &proc_dointvec,
1387                 .strategy       = &sysctl_intvec,
1388                 .extra1         = &zero,
1389         },
1390 #endif
1391 #ifdef CONFIG_HIGHMEM
1392         {
1393                 .ctl_name       = CTL_UNNUMBERED,
1394                 .procname       = "highmem_is_dirtyable",
1395                 .data           = &vm_highmem_is_dirtyable,
1396                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1397                 .mode           = 0644,
1398                 .proc_handler   = &proc_dointvec_minmax,
1399                 .strategy       = &sysctl_intvec,
1400                 .extra1         = &zero,
1401                 .extra2         = &one,
1402         },
1403 #endif
1404         {
1405                 .ctl_name       = CTL_UNNUMBERED,
1406                 .procname       = "scan_unevictable_pages",
1407                 .data           = &scan_unevictable_pages,
1408                 .maxlen         = sizeof(scan_unevictable_pages),
1409                 .mode           = 0644,
1410                 .proc_handler   = &scan_unevictable_handler,
1411         },
1412 #ifdef CONFIG_MEMORY_FAILURE
1413         {
1414                 .ctl_name       = CTL_UNNUMBERED,
1415                 .procname       = "memory_failure_early_kill",
1416                 .data           = &sysctl_memory_failure_early_kill,
1417                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1418                 .mode           = 0644,
1419                 .proc_handler   = &proc_dointvec_minmax,
1420                 .strategy       = &sysctl_intvec,
1421                 .extra1         = &zero,
1422                 .extra2         = &one,
1423         },
1424         {
1425                 .ctl_name       = CTL_UNNUMBERED,
1426                 .procname       = "memory_failure_recovery",
1427                 .data           = &sysctl_memory_failure_recovery,
1428                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1429                 .mode           = 0644,
1430                 .proc_handler   = &proc_dointvec_minmax,
1431                 .strategy       = &sysctl_intvec,
1432                 .extra1         = &zero,
1433                 .extra2         = &one,
1434         },
1435 #endif
1436
1437 /*
1438  * NOTE: do not add new entries to this table unless you have read
1439  * Documentation/sysctl/ctl_unnumbered.txt
1440  */
1441         { .ctl_name = 0 }
1442 };
1443
1444 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1445 static struct ctl_table binfmt_misc_table[] = {
1446         { .ctl_name = 0 }
1447 };
1448 #endif
1449
1450 static struct ctl_table fs_table[] = {
1451         {
1452                 .ctl_name       = FS_NRINODE,
1453                 .procname       = "inode-nr",
1454                 .data           = &inodes_stat,
1455                 .maxlen         = 2*sizeof(int),
1456                 .mode           = 0444,
1457                 .proc_handler   = &proc_dointvec,
1458         },
1459         {
1460                 .ctl_name       = FS_STATINODE,
1461                 .procname       = "inode-state",
1462                 .data           = &inodes_stat,
1463                 .maxlen         = 7*sizeof(int),
1464                 .mode           = 0444,
1465                 .proc_handler   = &proc_dointvec,
1466         },
1467         {
1468                 .procname       = "file-nr",
1469                 .data           = &files_stat,
1470                 .maxlen         = 3*sizeof(int),
1471                 .mode           = 0444,
1472                 .proc_handler   = &proc_nr_files,
1473         },
1474         {
1475                 .ctl_name       = FS_MAXFILE,
1476                 .procname       = "file-max",
1477                 .data           = &files_stat.max_files,
1478                 .maxlen         = sizeof(int),
1479                 .mode           = 0644,
1480                 .proc_handler   = &proc_dointvec,
1481         },
1482         {
1483                 .ctl_name       = CTL_UNNUMBERED,
1484                 .procname       = "nr_open",
1485                 .data           = &sysctl_nr_open,
1486                 .maxlen         = sizeof(int),
1487                 .mode           = 0644,
1488                 .proc_handler   = &proc_dointvec_minmax,
1489                 .extra1         = &sysctl_nr_open_min,
1490                 .extra2         = &sysctl_nr_open_max,
1491         },
1492         {
1493                 .ctl_name       = FS_DENTRY,
1494                 .procname       = "dentry-state",
1495                 .data           = &dentry_stat,
1496                 .maxlen         = 6*sizeof(int),
1497                 .mode           = 0444,
1498                 .proc_handler   = &proc_dointvec,
1499         },
1500         {
1501                 .ctl_name       = FS_OVERFLOWUID,
1502                 .procname       = "overflowuid",
1503                 .data           = &fs_overflowuid,
1504                 .maxlen         = sizeof(int),
1505                 .mode           = 0644,
1506                 .proc_handler   = &proc_dointvec_minmax,
1507                 .strategy       = &sysctl_intvec,
1508                 .extra1         = &minolduid,
1509                 .extra2         = &maxolduid,
1510         },
1511         {
1512                 .ctl_name       = FS_OVERFLOWGID,
1513                 .procname       = "overflowgid",
1514                 .data           = &fs_overflowgid,
1515                 .maxlen         = sizeof(int),
1516                 .mode           = 0644,
1517                 .proc_handler   = &proc_dointvec_minmax,
1518                 .strategy       = &sysctl_intvec,
1519                 .extra1         = &minolduid,
1520                 .extra2         = &maxolduid,
1521         },
1522 #ifdef CONFIG_FILE_LOCKING
1523         {
1524                 .ctl_name       = FS_LEASES,
1525                 .procname       = "leases-enable",
1526                 .data           = &leases_enable,
1527                 .maxlen         = sizeof(int),
1528                 .mode           = 0644,
1529                 .proc_handler   = &proc_dointvec,
1530         },
1531 #endif
1532 #ifdef CONFIG_DNOTIFY
1533         {
1534                 .ctl_name       = FS_DIR_NOTIFY,
1535                 .procname       = "dir-notify-enable",
1536                 .data           = &dir_notify_enable,
1537                 .maxlen         = sizeof(int),
1538                 .mode           = 0644,
1539                 .proc_handler   = &proc_dointvec,
1540         },
1541 #endif
1542 #ifdef CONFIG_MMU
1543 #ifdef CONFIG_FILE_LOCKING
1544         {
1545                 .ctl_name       = FS_LEASE_TIME,
1546                 .procname       = "lease-break-time",
1547                 .data           = &lease_break_time,
1548                 .maxlen         = sizeof(int),
1549                 .mode           = 0644,
1550                 .proc_handler   = &proc_dointvec,
1551         },
1552 #endif
1553 #ifdef CONFIG_AIO
1554         {
1555                 .procname       = "aio-nr",
1556                 .data           = &aio_nr,
1557                 .maxlen         = sizeof(aio_nr),
1558                 .mode           = 0444,
1559                 .proc_handler   = &proc_doulongvec_minmax,
1560         },
1561         {
1562                 .procname       = "aio-max-nr",
1563                 .data           = &aio_max_nr,
1564                 .maxlen         = sizeof(aio_max_nr),
1565                 .mode           = 0644,
1566                 .proc_handler   = &proc_doulongvec_minmax,
1567         },
1568 #endif /* CONFIG_AIO */
1569 #ifdef CONFIG_INOTIFY_USER
1570         {
1571                 .ctl_name       = FS_INOTIFY,
1572                 .procname       = "inotify",
1573                 .mode           = 0555,
1574                 .child          = inotify_table,
1575         },
1576 #endif
1577 #ifdef CONFIG_EPOLL
1578         {
1579                 .procname       = "epoll",
1580                 .mode           = 0555,
1581                 .child          = epoll_table,
1582         },
1583 #endif
1584 #endif
1585         {
1586                 .ctl_name       = KERN_SETUID_DUMPABLE,
1587                 .procname       = "suid_dumpable",
1588                 .data           = &suid_dumpable,
1589                 .maxlen         = sizeof(int),
1590                 .mode           = 0644,
1591                 .proc_handler   = &proc_dointvec_minmax,
1592                 .strategy       = &sysctl_intvec,
1593                 .extra1         = &zero,
1594                 .extra2         = &two,
1595         },
1596 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1597         {
1598                 .ctl_name       = CTL_UNNUMBERED,
1599                 .procname       = "binfmt_misc",
1600                 .mode           = 0555,
1601                 .child          = binfmt_misc_table,
1602         },
1603 #endif
1604 /*
1605  * NOTE: do not add new entries to this table unless you have read
1606  * Documentation/sysctl/ctl_unnumbered.txt
1607  */
1608         { .ctl_name = 0 }
1609 };
1610
1611 static struct ctl_table debug_table[] = {
1612 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1613         {
1614                 .ctl_name       = CTL_UNNUMBERED,
1615                 .procname       = "exception-trace",
1616                 .data           = &show_unhandled_signals,
1617                 .maxlen         = sizeof(int),
1618                 .mode           = 0644,
1619                 .proc_handler   = proc_dointvec_minmax,
1620                 .extra1         = &zero,
1621         },
1622 #endif
1623         { .ctl_name = 0 }
1624 };
1625
1626 static struct ctl_table dev_table[] = {
1627         { .ctl_name = 0 }
1628 };
1629
1630 static DEFINE_SPINLOCK(sysctl_lock);
1631
1632 /* called under sysctl_lock */
1633 static int use_table(struct ctl_table_header *p)
1634 {
1635         if (unlikely(p->unregistering))
1636                 return 0;
1637         p->used++;
1638         return 1;
1639 }
1640
1641 /* called under sysctl_lock */
1642 static void unuse_table(struct ctl_table_header *p)
1643 {
1644         if (!--p->used)
1645                 if (unlikely(p->unregistering))
1646                         complete(p->unregistering);
1647 }
1648
1649 /* called under sysctl_lock, will reacquire if has to wait */
1650 static void start_unregistering(struct ctl_table_header *p)
1651 {
1652         /*
1653          * if p->used is 0, nobody will ever touch that entry again;
1654          * we'll eliminate all paths to it before dropping sysctl_lock
1655          */
1656         if (unlikely(p->used)) {
1657                 struct completion wait;
1658                 init_completion(&wait);
1659                 p->unregistering = &wait;
1660                 spin_unlock(&sysctl_lock);
1661                 wait_for_completion(&wait);
1662                 spin_lock(&sysctl_lock);
1663         } else {
1664                 /* anything non-NULL; we'll never dereference it */
1665                 p->unregistering = ERR_PTR(-EINVAL);
1666         }
1667         /*
1668          * do not remove from the list until nobody holds it; walking the
1669          * list in do_sysctl() relies on that.
1670          */
1671         list_del_init(&p->ctl_entry);
1672 }
1673
1674 void sysctl_head_get(struct ctl_table_header *head)
1675 {
1676         spin_lock(&sysctl_lock);
1677         head->count++;
1678         spin_unlock(&sysctl_lock);
1679 }
1680
1681 void sysctl_head_put(struct ctl_table_header *head)
1682 {
1683         spin_lock(&sysctl_lock);
1684         if (!--head->count)
1685                 kfree(head);
1686         spin_unlock(&sysctl_lock);
1687 }
1688
1689 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1690 {
1691         if (!head)
1692                 BUG();
1693         spin_lock(&sysctl_lock);
1694         if (!use_table(head))
1695                 head = ERR_PTR(-ENOENT);
1696         spin_unlock(&sysctl_lock);
1697         return head;
1698 }
1699
1700 void sysctl_head_finish(struct ctl_table_header *head)
1701 {
1702         if (!head)
1703                 return;
1704         spin_lock(&sysctl_lock);
1705         unuse_table(head);
1706         spin_unlock(&sysctl_lock);
1707 }
1708
1709 static struct ctl_table_set *
1710 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1711 {
1712         struct ctl_table_set *set = &root->default_set;
1713         if (root->lookup)
1714                 set = root->lookup(root, namespaces);
1715         return set;
1716 }
1717
1718 static struct list_head *
1719 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1720 {
1721         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1722         return &set->list;
1723 }
1724
1725 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1726                                             struct ctl_table_header *prev)
1727 {
1728         struct ctl_table_root *root;
1729         struct list_head *header_list;
1730         struct ctl_table_header *head;
1731         struct list_head *tmp;
1732
1733         spin_lock(&sysctl_lock);
1734         if (prev) {
1735                 head = prev;
1736                 tmp = &prev->ctl_entry;
1737                 unuse_table(prev);
1738                 goto next;
1739         }
1740         tmp = &root_table_header.ctl_entry;
1741         for (;;) {
1742                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1743
1744                 if (!use_table(head))
1745                         goto next;
1746                 spin_unlock(&sysctl_lock);
1747                 return head;
1748         next:
1749                 root = head->root;
1750                 tmp = tmp->next;
1751                 header_list = lookup_header_list(root, namespaces);
1752                 if (tmp != header_list)
1753                         continue;
1754
1755                 do {
1756                         root = list_entry(root->root_list.next,
1757                                         struct ctl_table_root, root_list);
1758                         if (root == &sysctl_table_root)
1759                                 goto out;
1760                         header_list = lookup_header_list(root, namespaces);
1761                 } while (list_empty(header_list));
1762                 tmp = header_list->next;
1763         }
1764 out:
1765         spin_unlock(&sysctl_lock);
1766         return NULL;
1767 }
1768
1769 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1770 {
1771         return __sysctl_head_next(current->nsproxy, prev);
1772 }
1773
1774 void register_sysctl_root(struct ctl_table_root *root)
1775 {
1776         spin_lock(&sysctl_lock);
1777         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1778         spin_unlock(&sysctl_lock);
1779 }
1780
1781 #ifdef CONFIG_SYSCTL_SYSCALL
1782 /* Perform the actual read/write of a sysctl table entry. */
1783 static int do_sysctl_strategy(struct ctl_table_root *root,
1784                         struct ctl_table *table,
1785                         void __user *oldval, size_t __user *oldlenp,
1786                         void __user *newval, size_t newlen)
1787 {
1788         int op = 0, rc;
1789
1790         if (oldval)
1791                 op |= MAY_READ;
1792         if (newval)
1793                 op |= MAY_WRITE;
1794         if (sysctl_perm(root, table, op))
1795                 return -EPERM;
1796
1797         if (table->strategy) {
1798                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1799                 if (rc < 0)
1800                         return rc;
1801                 if (rc > 0)
1802                         return 0;
1803         }
1804
1805         /* If there is no strategy routine, or if the strategy returns
1806          * zero, proceed with automatic r/w */
1807         if (table->data && table->maxlen) {
1808                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1809                 if (rc < 0)
1810                         return rc;
1811         }
1812         return 0;
1813 }
1814
1815 static int parse_table(int __user *name, int nlen,
1816                        void __user *oldval, size_t __user *oldlenp,
1817                        void __user *newval, size_t newlen,
1818                        struct ctl_table_root *root,
1819                        struct ctl_table *table)
1820 {
1821         int n;
1822 repeat:
1823         if (!nlen)
1824                 return -ENOTDIR;
1825         if (get_user(n, name))
1826                 return -EFAULT;
1827         for ( ; table->ctl_name || table->procname; table++) {
1828                 if (!table->ctl_name)
1829                         continue;
1830                 if (n == table->ctl_name) {
1831                         int error;
1832                         if (table->child) {
1833                                 if (sysctl_perm(root, table, MAY_EXEC))
1834                                         return -EPERM;
1835                                 name++;
1836                                 nlen--;
1837                                 table = table->child;
1838                                 goto repeat;
1839                         }
1840                         error = do_sysctl_strategy(root, table,
1841                                                    oldval, oldlenp,
1842                                                    newval, newlen);
1843                         return error;
1844                 }
1845         }
1846         return -ENOTDIR;
1847 }
1848
1849 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1850                void __user *newval, size_t newlen)
1851 {
1852         struct ctl_table_header *head;
1853         int error = -ENOTDIR;
1854
1855         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1856                 return -ENOTDIR;
1857         if (oldval) {
1858                 int old_len;
1859                 if (!oldlenp || get_user(old_len, oldlenp))
1860                         return -EFAULT;
1861         }
1862
1863         for (head = sysctl_head_next(NULL); head;
1864                         head = sysctl_head_next(head)) {
1865                 error = parse_table(name, nlen, oldval, oldlenp,
1866                                         newval, newlen,
1867                                         head->root, head->ctl_table);
1868                 if (error != -ENOTDIR) {
1869                         sysctl_head_finish(head);
1870                         break;
1871                 }
1872         }
1873         return error;
1874 }
1875
1876 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1877 {
1878         struct __sysctl_args tmp;
1879         int error;
1880
1881         if (copy_from_user(&tmp, args, sizeof(tmp)))
1882                 return -EFAULT;
1883
1884         error = deprecated_sysctl_warning(&tmp);
1885         if (error)
1886                 goto out;
1887
1888         lock_kernel();
1889         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1890                           tmp.newval, tmp.newlen);
1891         unlock_kernel();
1892 out:
1893         return error;
1894 }
1895 #endif /* CONFIG_SYSCTL_SYSCALL */
1896
1897 /*
1898  * sysctl_perm does NOT grant the superuser all rights automatically, because
1899  * some sysctl variables are readonly even to root.
1900  */
1901
1902 static int test_perm(int mode, int op)
1903 {
1904         if (!current_euid())
1905                 mode >>= 6;
1906         else if (in_egroup_p(0))
1907                 mode >>= 3;
1908         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1909                 return 0;
1910         return -EACCES;
1911 }
1912
1913 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1914 {
1915         int error;
1916         int mode;
1917
1918         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1919         if (error)
1920                 return error;
1921
1922         if (root->permissions)
1923                 mode = root->permissions(root, current->nsproxy, table);
1924         else
1925                 mode = table->mode;
1926
1927         return test_perm(mode, op);
1928 }
1929
1930 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1931 {
1932         for (; table->ctl_name || table->procname; table++) {
1933                 table->parent = parent;
1934                 if (table->child)
1935                         sysctl_set_parent(table, table->child);
1936         }
1937 }
1938
1939 static __init int sysctl_init(void)
1940 {
1941         sysctl_set_parent(NULL, root_table);
1942 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1943         {
1944                 int err;
1945                 err = sysctl_check_table(current->nsproxy, root_table);
1946         }
1947 #endif
1948         return 0;
1949 }
1950
1951 core_initcall(sysctl_init);
1952
1953 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1954                                       struct ctl_table *table)
1955 {
1956         struct ctl_table *p;
1957         const char *s = branch->procname;
1958
1959         /* branch should have named subdirectory as its first element */
1960         if (!s || !branch->child)
1961                 return NULL;
1962
1963         /* ... and nothing else */
1964         if (branch[1].procname || branch[1].ctl_name)
1965                 return NULL;
1966
1967         /* table should contain subdirectory with the same name */
1968         for (p = table; p->procname || p->ctl_name; p++) {
1969                 if (!p->child)
1970                         continue;
1971                 if (p->procname && strcmp(p->procname, s) == 0)
1972                         return p;
1973         }
1974         return NULL;
1975 }
1976
1977 /* see if attaching q to p would be an improvement */
1978 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1979 {
1980         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1981         struct ctl_table *next;
1982         int is_better = 0;
1983         int not_in_parent = !p->attached_by;
1984
1985         while ((next = is_branch_in(by, to)) != NULL) {
1986                 if (by == q->attached_by)
1987                         is_better = 1;
1988                 if (to == p->attached_by)
1989                         not_in_parent = 1;
1990                 by = by->child;
1991                 to = next->child;
1992         }
1993
1994         if (is_better && not_in_parent) {
1995                 q->attached_by = by;
1996                 q->attached_to = to;
1997                 q->parent = p;
1998         }
1999 }
2000
2001 /**
2002  * __register_sysctl_paths - register a sysctl hierarchy
2003  * @root: List of sysctl headers to register on
2004  * @namespaces: Data to compute which lists of sysctl entries are visible
2005  * @path: The path to the directory the sysctl table is in.
2006  * @table: the top-level table structure
2007  *
2008  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2009  * array. A completely 0 filled entry terminates the table.
2010  *
2011  * The members of the &struct ctl_table structure are used as follows:
2012  *
2013  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
2014  *            must be unique within that level of sysctl
2015  *
2016  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
2017  *            enter a sysctl file
2018  *
2019  * data - a pointer to data for use by proc_handler
2020  *
2021  * maxlen - the maximum size in bytes of the data
2022  *
2023  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
2024  *
2025  * child - a pointer to the child sysctl table if this entry is a directory, or
2026  *         %NULL.
2027  *
2028  * proc_handler - the text handler routine (described below)
2029  *
2030  * strategy - the strategy routine (described below)
2031  *
2032  * de - for internal use by the sysctl routines
2033  *
2034  * extra1, extra2 - extra pointers usable by the proc handler routines
2035  *
2036  * Leaf nodes in the sysctl tree will be represented by a single file
2037  * under /proc; non-leaf nodes will be represented by directories.
2038  *
2039  * sysctl(2) can automatically manage read and write requests through
2040  * the sysctl table.  The data and maxlen fields of the ctl_table
2041  * struct enable minimal validation of the values being written to be
2042  * performed, and the mode field allows minimal authentication.
2043  *
2044  * More sophisticated management can be enabled by the provision of a
2045  * strategy routine with the table entry.  This will be called before
2046  * any automatic read or write of the data is performed.
2047  *
2048  * The strategy routine may return
2049  *
2050  * < 0 - Error occurred (error is passed to user process)
2051  *
2052  * 0   - OK - proceed with automatic read or write.
2053  *
2054  * > 0 - OK - read or write has been done by the strategy routine, so
2055  *       return immediately.
2056  *
2057  * There must be a proc_handler routine for any terminal nodes
2058  * mirrored under /proc/sys (non-terminals are handled by a built-in
2059  * directory handler).  Several default handlers are available to
2060  * cover common cases -
2061  *
2062  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
2063  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
2064  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
2065  *
2066  * It is the handler's job to read the input buffer from user memory
2067  * and process it. The handler should return 0 on success.
2068  *
2069  * This routine returns %NULL on a failure to register, and a pointer
2070  * to the table header on success.
2071  */
2072 struct ctl_table_header *__register_sysctl_paths(
2073         struct ctl_table_root *root,
2074         struct nsproxy *namespaces,
2075         const struct ctl_path *path, struct ctl_table *table)
2076 {
2077         struct ctl_table_header *header;
2078         struct ctl_table *new, **prevp;
2079         unsigned int n, npath;
2080         struct ctl_table_set *set;
2081
2082         /* Count the path components */
2083         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2084                 ;
2085
2086         /*
2087          * For each path component, allocate a 2-element ctl_table array.
2088          * The first array element will be filled with the sysctl entry
2089          * for this, the second will be the sentinel (ctl_name == 0).
2090          *
2091          * We allocate everything in one go so that we don't have to
2092          * worry about freeing additional memory in unregister_sysctl_table.
2093          */
2094         header = kzalloc(sizeof(struct ctl_table_header) +
2095                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2096         if (!header)
2097                 return NULL;
2098
2099         new = (struct ctl_table *) (header + 1);
2100
2101         /* Now connect the dots */
2102         prevp = &header->ctl_table;
2103         for (n = 0; n < npath; ++n, ++path) {
2104                 /* Copy the procname */
2105                 new->procname = path->procname;
2106                 new->ctl_name = path->ctl_name;
2107                 new->mode     = 0555;
2108
2109                 *prevp = new;
2110                 prevp = &new->child;
2111
2112                 new += 2;
2113         }
2114         *prevp = table;
2115         header->ctl_table_arg = table;
2116
2117         INIT_LIST_HEAD(&header->ctl_entry);
2118         header->used = 0;
2119         header->unregistering = NULL;
2120         header->root = root;
2121         sysctl_set_parent(NULL, header->ctl_table);
2122         header->count = 1;
2123 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2124         if (sysctl_check_table(namespaces, header->ctl_table)) {
2125                 kfree(header);
2126                 return NULL;
2127         }
2128 #endif
2129         spin_lock(&sysctl_lock);
2130         header->set = lookup_header_set(root, namespaces);
2131         header->attached_by = header->ctl_table;
2132         header->attached_to = root_table;
2133         header->parent = &root_table_header;
2134         for (set = header->set; set; set = set->parent) {
2135                 struct ctl_table_header *p;
2136                 list_for_each_entry(p, &set->list, ctl_entry) {
2137                         if (p->unregistering)
2138                                 continue;
2139                         try_attach(p, header);
2140                 }
2141         }
2142         header->parent->count++;
2143         list_add_tail(&header->ctl_entry, &header->set->list);
2144         spin_unlock(&sysctl_lock);
2145
2146         return header;
2147 }
2148
2149 /**
2150  * register_sysctl_table_path - register a sysctl table hierarchy
2151  * @path: The path to the directory the sysctl table is in.
2152  * @table: the top-level table structure
2153  *
2154  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2155  * array. A completely 0 filled entry terminates the table.
2156  *
2157  * See __register_sysctl_paths for more details.
2158  */
2159 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2160                                                 struct ctl_table *table)
2161 {
2162         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2163                                         path, table);
2164 }
2165
2166 /**
2167  * register_sysctl_table - register a sysctl table hierarchy
2168  * @table: the top-level table structure
2169  *
2170  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2171  * array. A completely 0 filled entry terminates the table.
2172  *
2173  * See register_sysctl_paths for more details.
2174  */
2175 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2176 {
2177         static const struct ctl_path null_path[] = { {} };
2178
2179         return register_sysctl_paths(null_path, table);
2180 }
2181
2182 /**
2183  * unregister_sysctl_table - unregister a sysctl table hierarchy
2184  * @header: the header returned from register_sysctl_table
2185  *
2186  * Unregisters the sysctl table and all children. proc entries may not
2187  * actually be removed until they are no longer used by anyone.
2188  */
2189 void unregister_sysctl_table(struct ctl_table_header * header)
2190 {
2191         might_sleep();
2192
2193         if (header == NULL)
2194                 return;
2195
2196         spin_lock(&sysctl_lock);
2197         start_unregistering(header);
2198         if (!--header->parent->count) {
2199                 WARN_ON(1);
2200                 kfree(header->parent);
2201         }
2202         if (!--header->count)
2203                 kfree(header);
2204         spin_unlock(&sysctl_lock);
2205 }
2206
2207 int sysctl_is_seen(struct ctl_table_header *p)
2208 {
2209         struct ctl_table_set *set = p->set;
2210         int res;
2211         spin_lock(&sysctl_lock);
2212         if (p->unregistering)
2213                 res = 0;
2214         else if (!set->is_seen)
2215                 res = 1;
2216         else
2217                 res = set->is_seen(set);
2218         spin_unlock(&sysctl_lock);
2219         return res;
2220 }
2221
2222 void setup_sysctl_set(struct ctl_table_set *p,
2223         struct ctl_table_set *parent,
2224         int (*is_seen)(struct ctl_table_set *))
2225 {
2226         INIT_LIST_HEAD(&p->list);
2227         p->parent = parent ? parent : &sysctl_table_root.default_set;
2228         p->is_seen = is_seen;
2229 }
2230
2231 #else /* !CONFIG_SYSCTL */
2232 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2233 {
2234         return NULL;
2235 }
2236
2237 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2238                                                     struct ctl_table *table)
2239 {
2240         return NULL;
2241 }
2242
2243 void unregister_sysctl_table(struct ctl_table_header * table)
2244 {
2245 }
2246
2247 void setup_sysctl_set(struct ctl_table_set *p,
2248         struct ctl_table_set *parent,
2249         int (*is_seen)(struct ctl_table_set *))
2250 {
2251 }
2252
2253 void sysctl_head_put(struct ctl_table_header *head)
2254 {
2255 }
2256
2257 #endif /* CONFIG_SYSCTL */
2258
2259 /*
2260  * /proc/sys support
2261  */
2262
2263 #ifdef CONFIG_PROC_SYSCTL
2264
2265 static int _proc_do_string(void* data, int maxlen, int write,
2266                            void __user *buffer,
2267                            size_t *lenp, loff_t *ppos)
2268 {
2269         size_t len;
2270         char __user *p;
2271         char c;
2272
2273         if (!data || !maxlen || !*lenp) {
2274                 *lenp = 0;
2275                 return 0;
2276         }
2277
2278         if (write) {
2279                 len = 0;
2280                 p = buffer;
2281                 while (len < *lenp) {
2282                         if (get_user(c, p++))
2283                                 return -EFAULT;
2284                         if (c == 0 || c == '\n')
2285                                 break;
2286                         len++;
2287                 }
2288                 if (len >= maxlen)
2289                         len = maxlen-1;
2290                 if(copy_from_user(data, buffer, len))
2291                         return -EFAULT;
2292                 ((char *) data)[len] = 0;
2293                 *ppos += *lenp;
2294         } else {
2295                 len = strlen(data);
2296                 if (len > maxlen)
2297                         len = maxlen;
2298
2299                 if (*ppos > len) {
2300                         *lenp = 0;
2301                         return 0;
2302                 }
2303
2304                 data += *ppos;
2305                 len  -= *ppos;
2306
2307                 if (len > *lenp)
2308                         len = *lenp;
2309                 if (len)
2310                         if(copy_to_user(buffer, data, len))
2311                                 return -EFAULT;
2312                 if (len < *lenp) {
2313                         if(put_user('\n', ((char __user *) buffer) + len))
2314                                 return -EFAULT;
2315                         len++;
2316                 }
2317                 *lenp = len;
2318                 *ppos += len;
2319         }
2320         return 0;
2321 }
2322
2323 /**
2324  * proc_dostring - read a string sysctl
2325  * @table: the sysctl table
2326  * @write: %TRUE if this is a write to the sysctl file
2327  * @buffer: the user buffer
2328  * @lenp: the size of the user buffer
2329  * @ppos: file position
2330  *
2331  * Reads/writes a string from/to the user buffer. If the kernel
2332  * buffer provided is not large enough to hold the string, the
2333  * string is truncated. The copied string is %NULL-terminated.
2334  * If the string is being read by the user process, it is copied
2335  * and a newline '\n' is added. It is truncated if the buffer is
2336  * not large enough.
2337  *
2338  * Returns 0 on success.
2339  */
2340 int proc_dostring(struct ctl_table *table, int write,
2341                   void __user *buffer, size_t *lenp, loff_t *ppos)
2342 {
2343         return _proc_do_string(table->data, table->maxlen, write,
2344                                buffer, lenp, ppos);
2345 }
2346
2347
2348 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2349                                  int *valp,
2350                                  int write, void *data)
2351 {
2352         if (write) {
2353                 *valp = *negp ? -*lvalp : *lvalp;
2354         } else {
2355                 int val = *valp;
2356                 if (val < 0) {
2357                         *negp = -1;
2358                         *lvalp = (unsigned long)-val;
2359                 } else {
2360                         *negp = 0;
2361                         *lvalp = (unsigned long)val;
2362                 }
2363         }
2364         return 0;
2365 }
2366
2367 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2368                   int write, void __user *buffer,
2369                   size_t *lenp, loff_t *ppos,
2370                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2371                               int write, void *data),
2372                   void *data)
2373 {
2374 #define TMPBUFLEN 21
2375         int *i, vleft, first = 1, neg;
2376         unsigned long lval;
2377         size_t left, len;
2378
2379         char buf[TMPBUFLEN], *p;
2380         char __user *s = buffer;
2381
2382         if (!tbl_data || !table->maxlen || !*lenp ||
2383             (*ppos && !write)) {
2384                 *lenp = 0;
2385                 return 0;
2386         }
2387
2388         i = (int *) tbl_data;
2389         vleft = table->maxlen / sizeof(*i);
2390         left = *lenp;
2391
2392         if (!conv)
2393                 conv = do_proc_dointvec_conv;
2394
2395         for (; left && vleft--; i++, first=0) {
2396                 if (write) {
2397                         while (left) {
2398                                 char c;
2399                                 if (get_user(c, s))
2400                                         return -EFAULT;
2401                                 if (!isspace(c))
2402                                         break;
2403                                 left--;
2404                                 s++;
2405                         }
2406                         if (!left)
2407                                 break;
2408                         neg = 0;
2409                         len = left;
2410                         if (len > sizeof(buf) - 1)
2411                                 len = sizeof(buf) - 1;
2412                         if (copy_from_user(buf, s, len))
2413                                 return -EFAULT;
2414                         buf[len] = 0;
2415                         p = buf;
2416                         if (*p == '-' && left > 1) {
2417                                 neg = 1;
2418                                 p++;
2419                         }
2420                         if (*p < '0' || *p > '9')
2421                                 break;
2422
2423                         lval = simple_strtoul(p, &p, 0);
2424
2425                         len = p-buf;
2426                         if ((len < left) && *p && !isspace(*p))
2427                                 break;
2428                         s += len;
2429                         left -= len;
2430
2431                         if (conv(&neg, &lval, i, 1, data))
2432                                 break;
2433                 } else {
2434                         p = buf;
2435                         if (!first)
2436                                 *p++ = '\t';
2437
2438                         if (conv(&neg, &lval, i, 0, data))
2439                                 break;
2440
2441                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2442                         len = strlen(buf);
2443                         if (len > left)
2444                                 len = left;
2445                         if(copy_to_user(s, buf, len))
2446                                 return -EFAULT;
2447                         left -= len;
2448                         s += len;
2449                 }
2450         }
2451
2452         if (!write && !first && left) {
2453                 if(put_user('\n', s))
2454                         return -EFAULT;
2455                 left--, s++;
2456         }
2457         if (write) {
2458                 while (left) {
2459                         char c;
2460                         if (get_user(c, s++))
2461                                 return -EFAULT;
2462                         if (!isspace(c))
2463                                 break;
2464                         left--;
2465                 }
2466         }
2467         if (write && first)
2468                 return -EINVAL;
2469         *lenp -= left;
2470         *ppos += *lenp;
2471         return 0;
2472 #undef TMPBUFLEN
2473 }
2474
2475 static int do_proc_dointvec(struct ctl_table *table, int write,
2476                   void __user *buffer, size_t *lenp, loff_t *ppos,
2477                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2478                               int write, void *data),
2479                   void *data)
2480 {
2481         return __do_proc_dointvec(table->data, table, write,
2482                         buffer, lenp, ppos, conv, data);
2483 }
2484
2485 /**
2486  * proc_dointvec - read a vector of integers
2487  * @table: the sysctl table
2488  * @write: %TRUE if this is a write to the sysctl file
2489  * @buffer: the user buffer
2490  * @lenp: the size of the user buffer
2491  * @ppos: file position
2492  *
2493  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2494  * values from/to the user buffer, treated as an ASCII string.
2495  *
2496  * Returns 0 on success.
2497  */
2498 int proc_dointvec(struct ctl_table *table, int write,
2499                      void __user *buffer, size_t *lenp, loff_t *ppos)
2500 {
2501     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2502                             NULL,NULL);
2503 }
2504
2505 /*
2506  * Taint values can only be increased
2507  * This means we can safely use a temporary.
2508  */
2509 static int proc_taint(struct ctl_table *table, int write,
2510                                void __user *buffer, size_t *lenp, loff_t *ppos)
2511 {
2512         struct ctl_table t;
2513         unsigned long tmptaint = get_taint();
2514         int err;
2515
2516         if (write && !capable(CAP_SYS_ADMIN))
2517                 return -EPERM;
2518
2519         t = *table;
2520         t.data = &tmptaint;
2521         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2522         if (err < 0)
2523                 return err;
2524
2525         if (write) {
2526                 /*
2527                  * Poor man's atomic or. Not worth adding a primitive
2528                  * to everyone's atomic.h for this
2529                  */
2530                 int i;
2531                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2532                         if ((tmptaint >> i) & 1)
2533                                 add_taint(i);
2534                 }
2535         }
2536
2537         return err;
2538 }
2539
2540 struct do_proc_dointvec_minmax_conv_param {
2541         int *min;
2542         int *max;
2543 };
2544
2545 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2546                                         int *valp,
2547                                         int write, void *data)
2548 {
2549         struct do_proc_dointvec_minmax_conv_param *param = data;
2550         if (write) {
2551                 int val = *negp ? -*lvalp : *lvalp;
2552                 if ((param->min && *param->min > val) ||
2553                     (param->max && *param->max < val))
2554                         return -EINVAL;
2555                 *valp = val;
2556         } else {
2557                 int val = *valp;
2558                 if (val < 0) {
2559                         *negp = -1;
2560                         *lvalp = (unsigned long)-val;
2561                 } else {
2562                         *negp = 0;
2563                         *lvalp = (unsigned long)val;
2564                 }
2565         }
2566         return 0;
2567 }
2568
2569 /**
2570  * proc_dointvec_minmax - read a vector of integers with min/max values
2571  * @table: the sysctl table
2572  * @write: %TRUE if this is a write to the sysctl file
2573  * @buffer: the user buffer
2574  * @lenp: the size of the user buffer
2575  * @ppos: file position
2576  *
2577  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2578  * values from/to the user buffer, treated as an ASCII string.
2579  *
2580  * This routine will ensure the values are within the range specified by
2581  * table->extra1 (min) and table->extra2 (max).
2582  *
2583  * Returns 0 on success.
2584  */
2585 int proc_dointvec_minmax(struct ctl_table *table, int write,
2586                   void __user *buffer, size_t *lenp, loff_t *ppos)
2587 {
2588         struct do_proc_dointvec_minmax_conv_param param = {
2589                 .min = (int *) table->extra1,
2590                 .max = (int *) table->extra2,
2591         };
2592         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2593                                 do_proc_dointvec_minmax_conv, &param);
2594 }
2595
2596 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2597                                      void __user *buffer,
2598                                      size_t *lenp, loff_t *ppos,
2599                                      unsigned long convmul,
2600                                      unsigned long convdiv)
2601 {
2602 #define TMPBUFLEN 21
2603         unsigned long *i, *min, *max, val;
2604         int vleft, first=1, neg;
2605         size_t len, left;
2606         char buf[TMPBUFLEN], *p;
2607         char __user *s = buffer;
2608
2609         if (!data || !table->maxlen || !*lenp ||
2610             (*ppos && !write)) {
2611                 *lenp = 0;
2612                 return 0;
2613         }
2614
2615         i = (unsigned long *) data;
2616         min = (unsigned long *) table->extra1;
2617         max = (unsigned long *) table->extra2;
2618         vleft = table->maxlen / sizeof(unsigned long);
2619         left = *lenp;
2620
2621         for (; left && vleft--; i++, min++, max++, first=0) {
2622                 if (write) {
2623                         while (left) {
2624                                 char c;
2625                                 if (get_user(c, s))
2626                                         return -EFAULT;
2627                                 if (!isspace(c))
2628                                         break;
2629                                 left--;
2630                                 s++;
2631                         }
2632                         if (!left)
2633                                 break;
2634                         neg = 0;
2635                         len = left;
2636                         if (len > TMPBUFLEN-1)
2637                                 len = TMPBUFLEN-1;
2638                         if (copy_from_user(buf, s, len))
2639                                 return -EFAULT;
2640                         buf[len] = 0;
2641                         p = buf;
2642                         if (*p == '-' && left > 1) {
2643                                 neg = 1;
2644                                 p++;
2645                         }
2646                         if (*p < '0' || *p > '9')
2647                                 break;
2648                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2649                         len = p-buf;
2650                         if ((len < left) && *p && !isspace(*p))
2651                                 break;
2652                         if (neg)
2653                                 val = -val;
2654                         s += len;
2655                         left -= len;
2656
2657                         if(neg)
2658                                 continue;
2659                         if ((min && val < *min) || (max && val > *max))
2660                                 continue;
2661                         *i = val;
2662                 } else {
2663                         p = buf;
2664                         if (!first)
2665                                 *p++ = '\t';
2666                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2667                         len = strlen(buf);
2668                         if (len > left)
2669                                 len = left;
2670                         if(copy_to_user(s, buf, len))
2671                                 return -EFAULT;
2672                         left -= len;
2673                         s += len;
2674                 }
2675         }
2676
2677         if (!write && !first && left) {
2678                 if(put_user('\n', s))
2679                         return -EFAULT;
2680                 left--, s++;
2681         }
2682         if (write) {
2683                 while (left) {
2684                         char c;
2685                         if (get_user(c, s++))
2686                                 return -EFAULT;
2687                         if (!isspace(c))
2688                                 break;
2689                         left--;
2690                 }
2691         }
2692         if (write && first)
2693                 return -EINVAL;
2694         *lenp -= left;
2695         *ppos += *lenp;
2696         return 0;
2697 #undef TMPBUFLEN
2698 }
2699
2700 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2701                                      void __user *buffer,
2702                                      size_t *lenp, loff_t *ppos,
2703                                      unsigned long convmul,
2704                                      unsigned long convdiv)
2705 {
2706         return __do_proc_doulongvec_minmax(table->data, table, write,
2707                         buffer, lenp, ppos, convmul, convdiv);
2708 }
2709
2710 /**
2711  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2712  * @table: the sysctl table
2713  * @write: %TRUE if this is a write to the sysctl file
2714  * @buffer: the user buffer
2715  * @lenp: the size of the user buffer
2716  * @ppos: file position
2717  *
2718  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2719  * values from/to the user buffer, treated as an ASCII string.
2720  *
2721  * This routine will ensure the values are within the range specified by
2722  * table->extra1 (min) and table->extra2 (max).
2723  *
2724  * Returns 0 on success.
2725  */
2726 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2727                            void __user *buffer, size_t *lenp, loff_t *ppos)
2728 {
2729     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2730 }
2731
2732 /**
2733  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2734  * @table: the sysctl table
2735  * @write: %TRUE if this is a write to the sysctl file
2736  * @buffer: the user buffer
2737  * @lenp: the size of the user buffer
2738  * @ppos: file position
2739  *
2740  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2741  * values from/to the user buffer, treated as an ASCII string. The values
2742  * are treated as milliseconds, and converted to jiffies when they are stored.
2743  *
2744  * This routine will ensure the values are within the range specified by
2745  * table->extra1 (min) and table->extra2 (max).
2746  *
2747  * Returns 0 on success.
2748  */
2749 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2750                                       void __user *buffer,
2751                                       size_t *lenp, loff_t *ppos)
2752 {
2753     return do_proc_doulongvec_minmax(table, write, buffer,
2754                                      lenp, ppos, HZ, 1000l);
2755 }
2756
2757
2758 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2759                                          int *valp,
2760                                          int write, void *data)
2761 {
2762         if (write) {
2763                 if (*lvalp > LONG_MAX / HZ)
2764                         return 1;
2765                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2766         } else {
2767                 int val = *valp;
2768                 unsigned long lval;
2769                 if (val < 0) {
2770                         *negp = -1;
2771                         lval = (unsigned long)-val;
2772                 } else {
2773                         *negp = 0;
2774                         lval = (unsigned long)val;
2775                 }
2776                 *lvalp = lval / HZ;
2777         }
2778         return 0;
2779 }
2780
2781 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2782                                                 int *valp,
2783                                                 int write, void *data)
2784 {
2785         if (write) {
2786                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2787                         return 1;
2788                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2789         } else {
2790                 int val = *valp;
2791                 unsigned long lval;
2792                 if (val < 0) {
2793                         *negp = -1;
2794                         lval = (unsigned long)-val;
2795                 } else {
2796                         *negp = 0;
2797                         lval = (unsigned long)val;
2798                 }
2799                 *lvalp = jiffies_to_clock_t(lval);
2800         }
2801         return 0;
2802 }
2803
2804 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2805                                             int *valp,
2806                                             int write, void *data)
2807 {
2808         if (write) {
2809                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2810         } else {
2811                 int val = *valp;
2812                 unsigned long lval;
2813                 if (val < 0) {
2814                         *negp = -1;
2815                         lval = (unsigned long)-val;
2816                 } else {
2817                         *negp = 0;
2818                         lval = (unsigned long)val;
2819                 }
2820                 *lvalp = jiffies_to_msecs(lval);
2821         }
2822         return 0;
2823 }
2824
2825 /**
2826  * proc_dointvec_jiffies - read a vector of integers as seconds
2827  * @table: the sysctl table
2828  * @write: %TRUE if this is a write to the sysctl file
2829  * @buffer: the user buffer
2830  * @lenp: the size of the user buffer
2831  * @ppos: file position
2832  *
2833  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2834  * values from/to the user buffer, treated as an ASCII string.
2835  * The values read are assumed to be in seconds, and are converted into
2836  * jiffies.
2837  *
2838  * Returns 0 on success.
2839  */
2840 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2841                           void __user *buffer, size_t *lenp, loff_t *ppos)
2842 {
2843     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2844                             do_proc_dointvec_jiffies_conv,NULL);
2845 }
2846
2847 /**
2848  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2849  * @table: the sysctl table
2850  * @write: %TRUE if this is a write to the sysctl file
2851  * @buffer: the user buffer
2852  * @lenp: the size of the user buffer
2853  * @ppos: pointer to the file position
2854  *
2855  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2856  * values from/to the user buffer, treated as an ASCII string.
2857  * The values read are assumed to be in 1/USER_HZ seconds, and
2858  * are converted into jiffies.
2859  *
2860  * Returns 0 on success.
2861  */
2862 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2863                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2864 {
2865     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2866                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2867 }
2868
2869 /**
2870  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2871  * @table: the sysctl table
2872  * @write: %TRUE if this is a write to the sysctl file
2873  * @buffer: the user buffer
2874  * @lenp: the size of the user buffer
2875  * @ppos: file position
2876  * @ppos: the current position in the file
2877  *
2878  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2879  * values from/to the user buffer, treated as an ASCII string.
2880  * The values read are assumed to be in 1/1000 seconds, and
2881  * are converted into jiffies.
2882  *
2883  * Returns 0 on success.
2884  */
2885 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2886                              void __user *buffer, size_t *lenp, loff_t *ppos)
2887 {
2888         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2889                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2890 }
2891
2892 static int proc_do_cad_pid(struct ctl_table *table, int write,
2893                            void __user *buffer, size_t *lenp, loff_t *ppos)
2894 {
2895         struct pid *new_pid;
2896         pid_t tmp;
2897         int r;
2898
2899         tmp = pid_vnr(cad_pid);
2900
2901         r = __do_proc_dointvec(&tmp, table, write, buffer,
2902                                lenp, ppos, NULL, NULL);
2903         if (r || !write)
2904                 return r;
2905
2906         new_pid = find_get_pid(tmp);
2907         if (!new_pid)
2908                 return -ESRCH;
2909
2910         put_pid(xchg(&cad_pid, new_pid));
2911         return 0;
2912 }
2913
2914 #else /* CONFIG_PROC_FS */
2915
2916 int proc_dostring(struct ctl_table *table, int write,
2917                   void __user *buffer, size_t *lenp, loff_t *ppos)
2918 {
2919         return -ENOSYS;
2920 }
2921
2922 int proc_dointvec(struct ctl_table *table, int write,
2923                   void __user *buffer, size_t *lenp, loff_t *ppos)
2924 {
2925         return -ENOSYS;
2926 }
2927
2928 int proc_dointvec_minmax(struct ctl_table *table, int write,
2929                     void __user *buffer, size_t *lenp, loff_t *ppos)
2930 {
2931         return -ENOSYS;
2932 }
2933
2934 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2935                     void __user *buffer, size_t *lenp, loff_t *ppos)
2936 {
2937         return -ENOSYS;
2938 }
2939
2940 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2941                     void __user *buffer, size_t *lenp, loff_t *ppos)
2942 {
2943         return -ENOSYS;
2944 }
2945
2946 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2947                              void __user *buffer, size_t *lenp, loff_t *ppos)
2948 {
2949         return -ENOSYS;
2950 }
2951
2952 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2953                     void __user *buffer, size_t *lenp, loff_t *ppos)
2954 {
2955         return -ENOSYS;
2956 }
2957
2958 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2959                                       void __user *buffer,
2960                                       size_t *lenp, loff_t *ppos)
2961 {
2962     return -ENOSYS;
2963 }
2964
2965
2966 #endif /* CONFIG_PROC_FS */
2967
2968
2969 #ifdef CONFIG_SYSCTL_SYSCALL
2970 /*
2971  * General sysctl support routines
2972  */
2973
2974 /* The generic sysctl data routine (used if no strategy routine supplied) */
2975 int sysctl_data(struct ctl_table *table,
2976                 void __user *oldval, size_t __user *oldlenp,
2977                 void __user *newval, size_t newlen)
2978 {
2979         size_t len;
2980
2981         /* Get out of I don't have a variable */
2982         if (!table->data || !table->maxlen)
2983                 return -ENOTDIR;
2984
2985         if (oldval && oldlenp) {
2986                 if (get_user(len, oldlenp))
2987                         return -EFAULT;
2988                 if (len) {
2989                         if (len > table->maxlen)
2990                                 len = table->maxlen;
2991                         if (copy_to_user(oldval, table->data, len))
2992                                 return -EFAULT;
2993                         if (put_user(len, oldlenp))
2994                                 return -EFAULT;
2995                 }
2996         }
2997
2998         if (newval && newlen) {
2999                 if (newlen > table->maxlen)
3000                         newlen = table->maxlen;
3001
3002                 if (copy_from_user(table->data, newval, newlen))
3003                         return -EFAULT;
3004         }
3005         return 1;
3006 }
3007
3008 /* The generic string strategy routine: */
3009 int sysctl_string(struct ctl_table *table,
3010                   void __user *oldval, size_t __user *oldlenp,
3011                   void __user *newval, size_t newlen)
3012 {
3013         if (!table->data || !table->maxlen)
3014                 return -ENOTDIR;
3015
3016         if (oldval && oldlenp) {
3017                 size_t bufsize;
3018                 if (get_user(bufsize, oldlenp))
3019                         return -EFAULT;
3020                 if (bufsize) {
3021                         size_t len = strlen(table->data), copied;
3022
3023                         /* This shouldn't trigger for a well-formed sysctl */
3024                         if (len > table->maxlen)
3025                                 len = table->maxlen;
3026
3027                         /* Copy up to a max of bufsize-1 bytes of the string */
3028                         copied = (len >= bufsize) ? bufsize - 1 : len;
3029
3030                         if (copy_to_user(oldval, table->data, copied) ||
3031                             put_user(0, (char __user *)(oldval + copied)))
3032                                 return -EFAULT;
3033                         if (put_user(len, oldlenp))
3034                                 return -EFAULT;
3035                 }
3036         }
3037         if (newval && newlen) {
3038                 size_t len = newlen;
3039                 if (len > table->maxlen)
3040                         len = table->maxlen;
3041                 if(copy_from_user(table->data, newval, len))
3042                         return -EFAULT;
3043                 if (len == table->maxlen)
3044                         len--;
3045                 ((char *) table->data)[len] = 0;
3046         }
3047         return 1;
3048 }
3049
3050 /*
3051  * This function makes sure that all of the integers in the vector
3052  * are between the minimum and maximum values given in the arrays
3053  * table->extra1 and table->extra2, respectively.
3054  */
3055 int sysctl_intvec(struct ctl_table *table,
3056                 void __user *oldval, size_t __user *oldlenp,
3057                 void __user *newval, size_t newlen)
3058 {
3059
3060         if (newval && newlen) {
3061                 int __user *vec = (int __user *) newval;
3062                 int *min = (int *) table->extra1;
3063                 int *max = (int *) table->extra2;
3064                 size_t length;
3065                 int i;
3066
3067                 if (newlen % sizeof(int) != 0)
3068                         return -EINVAL;
3069
3070                 if (!table->extra1 && !table->extra2)
3071                         return 0;
3072
3073                 if (newlen > table->maxlen)
3074                         newlen = table->maxlen;
3075                 length = newlen / sizeof(int);
3076
3077                 for (i = 0; i < length; i++) {
3078                         int value;
3079                         if (get_user(value, vec + i))
3080                                 return -EFAULT;
3081                         if (min && value < min[i])
3082                                 return -EINVAL;
3083                         if (max && value > max[i])
3084                                 return -EINVAL;
3085                 }
3086         }
3087         return 0;
3088 }
3089
3090 /* Strategy function to convert jiffies to seconds */
3091 int sysctl_jiffies(struct ctl_table *table,
3092                 void __user *oldval, size_t __user *oldlenp,
3093                 void __user *newval, size_t newlen)
3094 {
3095         if (oldval && oldlenp) {
3096                 size_t olen;
3097
3098                 if (get_user(olen, oldlenp))
3099                         return -EFAULT;
3100                 if (olen) {
3101                         int val;
3102
3103                         if (olen < sizeof(int))
3104                                 return -EINVAL;
3105
3106                         val = *(int *)(table->data) / HZ;
3107                         if (put_user(val, (int __user *)oldval))
3108                                 return -EFAULT;
3109                         if (put_user(sizeof(int), oldlenp))
3110                                 return -EFAULT;
3111                 }
3112         }
3113         if (newval && newlen) {
3114                 int new;
3115                 if (newlen != sizeof(int))
3116                         return -EINVAL;
3117                 if (get_user(new, (int __user *)newval))
3118                         return -EFAULT;
3119                 *(int *)(table->data) = new*HZ;
3120         }
3121         return 1;
3122 }
3123
3124 /* Strategy function to convert jiffies to seconds */
3125 int sysctl_ms_jiffies(struct ctl_table *table,
3126                 void __user *oldval, size_t __user *oldlenp,
3127                 void __user *newval, size_t newlen)
3128 {
3129         if (oldval && oldlenp) {
3130                 size_t olen;
3131
3132                 if (get_user(olen, oldlenp))
3133                         return -EFAULT;
3134                 if (olen) {
3135                         int val;
3136
3137                         if (olen < sizeof(int))
3138                                 return -EINVAL;
3139
3140                         val = jiffies_to_msecs(*(int *)(table->data));
3141                         if (put_user(val, (int __user *)oldval))
3142                                 return -EFAULT;
3143                         if (put_user(sizeof(int), oldlenp))
3144                                 return -EFAULT;
3145                 }
3146         }
3147         if (newval && newlen) {
3148                 int new;
3149                 if (newlen != sizeof(int))
3150                         return -EINVAL;
3151                 if (get_user(new, (int __user *)newval))
3152                         return -EFAULT;
3153                 *(int *)(table->data) = msecs_to_jiffies(new);
3154         }
3155         return 1;
3156 }
3157
3158
3159
3160 #else /* CONFIG_SYSCTL_SYSCALL */
3161
3162
3163 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3164 {
3165         struct __sysctl_args tmp;
3166         int error;
3167
3168         if (copy_from_user(&tmp, args, sizeof(tmp)))
3169                 return -EFAULT;
3170
3171         error = deprecated_sysctl_warning(&tmp);
3172
3173         /* If no error reading the parameters then just -ENOSYS ... */
3174         if (!error)
3175                 error = -ENOSYS;
3176
3177         return error;
3178 }
3179
3180 int sysctl_data(struct ctl_table *table,
3181                   void __user *oldval, size_t __user *oldlenp,
3182                   void __user *newval, size_t newlen)
3183 {
3184         return -ENOSYS;
3185 }
3186
3187 int sysctl_string(struct ctl_table *table,
3188                   void __user *oldval, size_t __user *oldlenp,
3189                   void __user *newval, size_t newlen)
3190 {
3191         return -ENOSYS;
3192 }
3193
3194 int sysctl_intvec(struct ctl_table *table,
3195                 void __user *oldval, size_t __user *oldlenp,
3196                 void __user *newval, size_t newlen)
3197 {
3198         return -ENOSYS;
3199 }
3200
3201 int sysctl_jiffies(struct ctl_table *table,
3202                 void __user *oldval, size_t __user *oldlenp,
3203                 void __user *newval, size_t newlen)
3204 {
3205         return -ENOSYS;
3206 }
3207
3208 int sysctl_ms_jiffies(struct ctl_table *table,
3209                 void __user *oldval, size_t __user *oldlenp,
3210                 void __user *newval, size_t newlen)
3211 {
3212         return -ENOSYS;
3213 }
3214
3215 #endif /* CONFIG_SYSCTL_SYSCALL */
3216
3217 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3218 {
3219         static int msg_count;
3220         int name[CTL_MAXNAME];
3221         int i;
3222
3223         /* Check args->nlen. */
3224         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3225                 return -ENOTDIR;
3226
3227         /* Read in the sysctl name for better debug message logging */
3228         for (i = 0; i < args->nlen; i++)
3229                 if (get_user(name[i], args->name + i))
3230                         return -EFAULT;
3231
3232         /* Ignore accesses to kernel.version */
3233         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3234                 return 0;
3235
3236         if (msg_count < 5) {
3237                 msg_count++;
3238                 printk(KERN_INFO
3239                         "warning: process `%s' used the deprecated sysctl "
3240                         "system call with ", current->comm);
3241                 for (i = 0; i < args->nlen; i++)
3242                         printk("%d.", name[i]);
3243                 printk("\n");
3244         }
3245         return 0;
3246 }
3247
3248 /*
3249  * No sense putting this after each symbol definition, twice,
3250  * exception granted :-)
3251  */
3252 EXPORT_SYMBOL(proc_dointvec);
3253 EXPORT_SYMBOL(proc_dointvec_jiffies);
3254 EXPORT_SYMBOL(proc_dointvec_minmax);
3255 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3256 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3257 EXPORT_SYMBOL(proc_dostring);
3258 EXPORT_SYMBOL(proc_doulongvec_minmax);
3259 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3260 EXPORT_SYMBOL(register_sysctl_table);
3261 EXPORT_SYMBOL(register_sysctl_paths);
3262 EXPORT_SYMBOL(sysctl_intvec);
3263 EXPORT_SYMBOL(sysctl_jiffies);
3264 EXPORT_SYMBOL(sysctl_ms_jiffies);
3265 EXPORT_SYMBOL(sysctl_string);
3266 EXPORT_SYMBOL(sysctl_data);
3267 EXPORT_SYMBOL(unregister_sysctl_table);