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/ratelimit.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_event.h>
  54
  55 #include <asm/uaccess.h>
  56 #include <asm/processor.h>
  57
  58 #ifdef CONFIG_X86
  59 #include <asm/nmi.h>
  60 #include <asm/stacktrace.h>
  61 #include <asm/io.h>
  62 #endif
  63
  64 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  65
  66 #if defined(CONFIG_SYSCTL)
  67
  68 /* External variables not in a header file. */
  69 extern int C_A_D;
  70 extern int print_fatal_signals;
  71 extern int sysctl_overcommit_memory;
  72 extern int sysctl_overcommit_ratio;
  73 extern int sysctl_panic_on_oom;
  74 extern int sysctl_oom_kill_allocating_task;
  75 extern int sysctl_oom_dump_tasks;
  76 extern int max_threads;
  77 extern int core_uses_pid;
  78 extern int suid_dumpable;
  79 extern char core_pattern[];
  80 extern unsigned int core_pipe_limit;
  81 extern int pid_max;
  82 extern int min_free_kbytes;
  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 extern struct ratelimit_state printk_ratelimit_state;
 163
 164 #ifdef CONFIG_RT_MUTEXES
 165 extern int max_lock_depth;
 166 #endif
 167
 168 #ifdef CONFIG_PROC_SYSCTL
 169 static int proc_do_cad_pid(struct ctl_table *table, int write,
 170                   void __user *buffer, size_t *lenp, loff_t *ppos);
 171 static int proc_taint(struct ctl_table *table, int write,
 172                                void __user *buffer, size_t *lenp, loff_t *ppos);
 173 #endif
 174
 175 static struct ctl_table root_table[];
 176 static struct ctl_table_root sysctl_table_root;
 177 static struct ctl_table_header root_table_header = {
 178         .count = 1,
 179         .ctl_table = root_table,
 180         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 181         .root = &sysctl_table_root,
 182         .set = &sysctl_table_root.default_set,
 183 };
 184 static struct ctl_table_root sysctl_table_root = {
 185         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 186         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 187 };
 188
 189 static struct ctl_table kern_table[];
 190 static struct ctl_table vm_table[];
 191 static struct ctl_table fs_table[];
 192 static struct ctl_table debug_table[];
 193 static struct ctl_table dev_table[];
 194 extern struct ctl_table random_table[];
 195 #ifdef CONFIG_INOTIFY_USER
 196 extern struct ctl_table inotify_table[];
 197 #endif
 198 #ifdef CONFIG_EPOLL
 199 extern struct ctl_table epoll_table[];
 200 #endif
 201
 202 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 203 int sysctl_legacy_va_layout;
 204 #endif
 205
 206 extern int prove_locking;
 207 extern int lock_stat;
 208
 209 /* The default sysctl tables: */
 210
 211 static struct ctl_table root_table[] = {
 212         {
 213                 .ctl_name       = CTL_KERN,
 214                 .procname       = "kernel",
 215                 .mode           = 0555,
 216                 .child          = kern_table,
 217         },
 218         {
 219                 .ctl_name       = CTL_VM,
 220                 .procname       = "vm",
 221                 .mode           = 0555,
 222                 .child          = vm_table,
 223         },
 224         {
 225                 .ctl_name       = CTL_FS,
 226                 .procname       = "fs",
 227                 .mode           = 0555,
 228                 .child          = fs_table,
 229         },
 230         {
 231                 .ctl_name       = CTL_DEBUG,
 232                 .procname       = "debug",
 233                 .mode           = 0555,
 234                 .child          = debug_table,
 235         },
 236         {
 237                 .ctl_name       = CTL_DEV,
 238                 .procname       = "dev",
 239                 .mode           = 0555,
 240                 .child          = dev_table,
 241         },
 242 /*
 243  * NOTE: do not add new entries to this table unless you have read
 244  * Documentation/sysctl/ctl_unnumbered.txt
 245  */
 246         { .ctl_name = 0 }
 247 };
 248
 249 #ifdef CONFIG_SCHED_DEBUG
 250 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 251 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 252 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 253 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 254 #endif
 255
 256 static struct ctl_table kern_table[] = {
 257         {
 258                 .ctl_name       = CTL_UNNUMBERED,
 259                 .procname       = "sched_child_runs_first",
 260                 .data           = &sysctl_sched_child_runs_first,
 261                 .maxlen         = sizeof(unsigned int),
 262                 .mode           = 0644,
 263                 .proc_handler   = &proc_dointvec,
 264         },
 265 #ifdef CONFIG_SCHED_DEBUG
 266         {
 267                 .ctl_name       = CTL_UNNUMBERED,
 268                 .procname       = "sched_min_granularity_ns",
 269                 .data           = &sysctl_sched_min_granularity,
 270                 .maxlen         = sizeof(unsigned int),
 271                 .mode           = 0644,
 272                 .proc_handler   = &sched_nr_latency_handler,
 273                 .strategy       = &sysctl_intvec,
 274                 .extra1         = &min_sched_granularity_ns,
 275                 .extra2         = &max_sched_granularity_ns,
 276         },
 277         {
 278                 .ctl_name       = CTL_UNNUMBERED,
 279                 .procname       = "sched_latency_ns",
 280                 .data           = &sysctl_sched_latency,
 281                 .maxlen         = sizeof(unsigned int),
 282                 .mode           = 0644,
 283                 .proc_handler   = &sched_nr_latency_handler,
 284                 .strategy       = &sysctl_intvec,
 285                 .extra1         = &min_sched_granularity_ns,
 286                 .extra2         = &max_sched_granularity_ns,
 287         },
 288         {
 289                 .ctl_name       = CTL_UNNUMBERED,
 290                 .procname       = "sched_wakeup_granularity_ns",
 291                 .data           = &sysctl_sched_wakeup_granularity,
 292                 .maxlen         = sizeof(unsigned int),
 293                 .mode           = 0644,
 294                 .proc_handler   = &proc_dointvec_minmax,
 295                 .strategy       = &sysctl_intvec,
 296                 .extra1         = &min_wakeup_granularity_ns,
 297                 .extra2         = &max_wakeup_granularity_ns,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_shares_ratelimit",
 302                 .data           = &sysctl_sched_shares_ratelimit,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec,
 306         },
 307         {
 308                 .ctl_name       = CTL_UNNUMBERED,
 309                 .procname       = "sched_shares_thresh",
 310                 .data           = &sysctl_sched_shares_thresh,
 311                 .maxlen         = sizeof(unsigned int),
 312                 .mode           = 0644,
 313                 .proc_handler   = &proc_dointvec_minmax,
 314                 .strategy       = &sysctl_intvec,
 315                 .extra1         = &zero,
 316         },
 317         {
 318                 .ctl_name       = CTL_UNNUMBERED,
 319                 .procname       = "sched_features",
 320                 .data           = &sysctl_sched_features,
 321                 .maxlen         = sizeof(unsigned int),
 322                 .mode           = 0644,
 323                 .proc_handler   = &proc_dointvec,
 324         },
 325         {
 326                 .ctl_name       = CTL_UNNUMBERED,
 327                 .procname       = "sched_migration_cost",
 328                 .data           = &sysctl_sched_migration_cost,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = &proc_dointvec,
 332         },
 333         {
 334                 .ctl_name       = CTL_UNNUMBERED,
 335                 .procname       = "sched_nr_migrate",
 336                 .data           = &sysctl_sched_nr_migrate,
 337                 .maxlen         = sizeof(unsigned int),
 338                 .mode           = 0644,
 339                 .proc_handler   = &proc_dointvec,
 340         },
 341         {
 342                 .ctl_name       = CTL_UNNUMBERED,
 343                 .procname       = "sched_time_avg",
 344                 .data           = &sysctl_sched_time_avg,
 345                 .maxlen         = sizeof(unsigned int),
 346                 .mode           = 0644,
 347                 .proc_handler   = &proc_dointvec,
 348         },
 349         {
 350                 .ctl_name       = CTL_UNNUMBERED,
 351                 .procname       = "timer_migration",
 352                 .data           = &sysctl_timer_migration,
 353                 .maxlen         = sizeof(unsigned int),
 354                 .mode           = 0644,
 355                 .proc_handler   = &proc_dointvec_minmax,
 356                 .strategy       = &sysctl_intvec,
 357                 .extra1         = &zero,
 358                 .extra2         = &one,
 359         },
 360 #endif
 361         {
 362                 .ctl_name       = CTL_UNNUMBERED,
 363                 .procname       = "sched_rt_period_us",
 364                 .data           = &sysctl_sched_rt_period,
 365                 .maxlen         = sizeof(unsigned int),
 366                 .mode           = 0644,
 367                 .proc_handler   = &sched_rt_handler,
 368         },
 369         {
 370                 .ctl_name       = CTL_UNNUMBERED,
 371                 .procname       = "sched_rt_runtime_us",
 372                 .data           = &sysctl_sched_rt_runtime,
 373                 .maxlen         = sizeof(int),
 374                 .mode           = 0644,
 375                 .proc_handler   = &sched_rt_handler,
 376         },
 377         {
 378                 .ctl_name       = CTL_UNNUMBERED,
 379                 .procname       = "sched_compat_yield",
 380                 .data           = &sysctl_sched_compat_yield,
 381                 .maxlen         = sizeof(unsigned int),
 382                 .mode           = 0644,
 383                 .proc_handler   = &proc_dointvec,
 384         },
 385 #ifdef CONFIG_PROVE_LOCKING
 386         {
 387                 .ctl_name       = CTL_UNNUMBERED,
 388                 .procname       = "prove_locking",
 389                 .data           = &prove_locking,
 390                 .maxlen         = sizeof(int),
 391                 .mode           = 0644,
 392                 .proc_handler   = &proc_dointvec,
 393         },
 394 #endif
 395 #ifdef CONFIG_LOCK_STAT
 396         {
 397                 .ctl_name       = CTL_UNNUMBERED,
 398                 .procname       = "lock_stat",
 399                 .data           = &lock_stat,
 400                 .maxlen         = sizeof(int),
 401                 .mode           = 0644,
 402                 .proc_handler   = &proc_dointvec,
 403         },
 404 #endif
 405         {
 406                 .ctl_name       = KERN_PANIC,
 407                 .procname       = "panic",
 408                 .data           = &panic_timeout,
 409                 .maxlen         = sizeof(int),
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dointvec,
 412         },
 413         {
 414                 .ctl_name       = KERN_CORE_USES_PID,
 415                 .procname       = "core_uses_pid",
 416                 .data           = &core_uses_pid,
 417                 .maxlen         = sizeof(int),
 418                 .mode           = 0644,
 419                 .proc_handler   = &proc_dointvec,
 420         },
 421         {
 422                 .ctl_name       = KERN_CORE_PATTERN,
 423                 .procname       = "core_pattern",
 424                 .data           = core_pattern,
 425                 .maxlen         = CORENAME_MAX_SIZE,
 426                 .mode           = 0644,
 427                 .proc_handler   = &proc_dostring,
 428                 .strategy       = &sysctl_string,
 429         },
 430         {
 431                 .ctl_name       = CTL_UNNUMBERED,
 432                 .procname       = "core_pipe_limit",
 433                 .data           = &core_pipe_limit,
 434                 .maxlen         = sizeof(unsigned int),
 435                 .mode           = 0644,
 436                 .proc_handler   = &proc_dointvec,
 437         },
 438 #ifdef CONFIG_PROC_SYSCTL
 439         {
 440                 .procname       = "tainted",
 441                 .maxlen         = sizeof(long),
 442                 .mode           = 0644,
 443                 .proc_handler   = &proc_taint,
 444         },
 445 #endif
 446 #ifdef CONFIG_LATENCYTOP
 447         {
 448                 .procname       = "latencytop",
 449                 .data           = &latencytop_enabled,
 450                 .maxlen         = sizeof(int),
 451                 .mode           = 0644,
 452                 .proc_handler   = &proc_dointvec,
 453         },
 454 #endif
 455 #ifdef CONFIG_BLK_DEV_INITRD
 456         {
 457                 .ctl_name       = KERN_REALROOTDEV,
 458                 .procname       = "real-root-dev",
 459                 .data           = &real_root_dev,
 460                 .maxlen         = sizeof(int),
 461                 .mode           = 0644,
 462                 .proc_handler   = &proc_dointvec,
 463         },
 464 #endif
 465         {
 466                 .ctl_name       = CTL_UNNUMBERED,
 467                 .procname       = "print-fatal-signals",
 468                 .data           = &print_fatal_signals,
 469                 .maxlen         = sizeof(int),
 470                 .mode           = 0644,
 471                 .proc_handler   = &proc_dointvec,
 472         },
 473 #ifdef CONFIG_SPARC
 474         {
 475                 .ctl_name       = KERN_SPARC_REBOOT,
 476                 .procname       = "reboot-cmd",
 477                 .data           = reboot_command,
 478                 .maxlen         = 256,
 479                 .mode           = 0644,
 480                 .proc_handler   = &proc_dostring,
 481                 .strategy       = &sysctl_string,
 482         },
 483         {
 484                 .ctl_name       = KERN_SPARC_STOP_A,
 485                 .procname       = "stop-a",
 486                 .data           = &stop_a_enabled,
 487                 .maxlen         = sizeof (int),
 488                 .mode           = 0644,
 489                 .proc_handler   = &proc_dointvec,
 490         },
 491         {
 492                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 493                 .procname       = "scons-poweroff",
 494                 .data           = &scons_pwroff,
 495                 .maxlen         = sizeof (int),
 496                 .mode           = 0644,
 497                 .proc_handler   = &proc_dointvec,
 498         },
 499 #endif
 500 #ifdef CONFIG_SPARC64
 501         {
 502                 .ctl_name       = CTL_UNNUMBERED,
 503                 .procname       = "tsb-ratio",
 504                 .data           = &sysctl_tsb_ratio,
 505                 .maxlen         = sizeof (int),
 506                 .mode           = 0644,
 507                 .proc_handler   = &proc_dointvec,
 508         },
 509 #endif
 510 #ifdef __hppa__
 511         {
 512                 .ctl_name       = KERN_HPPA_PWRSW,
 513                 .procname       = "soft-power",
 514                 .data           = &pwrsw_enabled,
 515                 .maxlen         = sizeof (int),
 516                 .mode           = 0644,
 517                 .proc_handler   = &proc_dointvec,
 518         },
 519         {
 520                 .ctl_name       = KERN_HPPA_UNALIGNED,
 521                 .procname       = "unaligned-trap",
 522                 .data           = &unaligned_enabled,
 523                 .maxlen         = sizeof (int),
 524                 .mode           = 0644,
 525                 .proc_handler   = &proc_dointvec,
 526         },
 527 #endif
 528         {
 529                 .ctl_name       = KERN_CTLALTDEL,
 530                 .procname       = "ctrl-alt-del",
 531                 .data           = &C_A_D,
 532                 .maxlen         = sizeof(int),
 533                 .mode           = 0644,
 534                 .proc_handler   = &proc_dointvec,
 535         },
 536 #ifdef CONFIG_FUNCTION_TRACER
 537         {
 538                 .ctl_name       = CTL_UNNUMBERED,
 539                 .procname       = "ftrace_enabled",
 540                 .data           = &ftrace_enabled,
 541                 .maxlen         = sizeof(int),
 542                 .mode           = 0644,
 543                 .proc_handler   = &ftrace_enable_sysctl,
 544         },
 545 #endif
 546 #ifdef CONFIG_STACK_TRACER
 547         {
 548                 .ctl_name       = CTL_UNNUMBERED,
 549                 .procname       = "stack_tracer_enabled",
 550                 .data           = &stack_tracer_enabled,
 551                 .maxlen         = sizeof(int),
 552                 .mode           = 0644,
 553                 .proc_handler   = &stack_trace_sysctl,
 554         },
 555 #endif
 556 #ifdef CONFIG_TRACING
 557         {
 558                 .ctl_name       = CTL_UNNUMBERED,
 559                 .procname       = "ftrace_dump_on_oops",
 560                 .data           = &ftrace_dump_on_oops,
 561                 .maxlen         = sizeof(int),
 562                 .mode           = 0644,
 563                 .proc_handler   = &proc_dointvec,
 564         },
 565 #endif
 566 #ifdef CONFIG_MODULES
 567         {
 568                 .ctl_name       = KERN_MODPROBE,
 569                 .procname       = "modprobe",
 570                 .data           = &modprobe_path,
 571                 .maxlen         = KMOD_PATH_LEN,
 572                 .mode           = 0644,
 573                 .proc_handler   = &proc_dostring,
 574                 .strategy       = &sysctl_string,
 575         },
 576         {
 577                 .ctl_name       = CTL_UNNUMBERED,
 578                 .procname       = "modules_disabled",
 579                 .data           = &modules_disabled,
 580                 .maxlen         = sizeof(int),
 581                 .mode           = 0644,
 582                 /* only handle a transition from default "0" to "1" */
 583                 .proc_handler   = &proc_dointvec_minmax,
 584                 .extra1         = &one,
 585                 .extra2         = &one,
 586         },
 587 #endif
 588 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 589         {
 590                 .ctl_name       = KERN_HOTPLUG,
 591                 .procname       = "hotplug",
 592                 .data           = &uevent_helper,
 593                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 594                 .mode           = 0644,
 595                 .proc_handler   = &proc_dostring,
 596                 .strategy       = &sysctl_string,
 597         },
 598 #endif
 599 #ifdef CONFIG_CHR_DEV_SG
 600         {
 601                 .ctl_name       = KERN_SG_BIG_BUFF,
 602                 .procname       = "sg-big-buff",
 603                 .data           = &sg_big_buff,
 604                 .maxlen         = sizeof (int),
 605                 .mode           = 0444,
 606                 .proc_handler   = &proc_dointvec,
 607         },
 608 #endif
 609 #ifdef CONFIG_BSD_PROCESS_ACCT
 610         {
 611                 .ctl_name       = KERN_ACCT,
 612                 .procname       = "acct",
 613                 .data           = &acct_parm,
 614                 .maxlen         = 3*sizeof(int),
 615                 .mode           = 0644,
 616                 .proc_handler   = &proc_dointvec,
 617         },
 618 #endif
 619 #ifdef CONFIG_MAGIC_SYSRQ
 620         {
 621                 .ctl_name       = KERN_SYSRQ,
 622                 .procname       = "sysrq",
 623                 .data           = &__sysrq_enabled,
 624                 .maxlen         = sizeof (int),
 625                 .mode           = 0644,
 626                 .proc_handler   = &proc_dointvec,
 627         },
 628 #endif
 629 #ifdef CONFIG_PROC_SYSCTL
 630         {
 631                 .procname       = "cad_pid",
 632                 .data           = NULL,
 633                 .maxlen         = sizeof (int),
 634                 .mode           = 0600,
 635                 .proc_handler   = &proc_do_cad_pid,
 636         },
 637 #endif
 638         {
 639                 .ctl_name       = KERN_MAX_THREADS,
 640                 .procname       = "threads-max",
 641                 .data           = &max_threads,
 642                 .maxlen         = sizeof(int),
 643                 .mode           = 0644,
 644                 .proc_handler   = &proc_dointvec,
 645         },
 646         {
 647                 .ctl_name       = KERN_RANDOM,
 648                 .procname       = "random",
 649                 .mode           = 0555,
 650                 .child          = random_table,
 651         },
 652         {
 653                 .ctl_name       = KERN_OVERFLOWUID,
 654                 .procname       = "overflowuid",
 655                 .data           = &overflowuid,
 656                 .maxlen         = sizeof(int),
 657                 .mode           = 0644,
 658                 .proc_handler   = &proc_dointvec_minmax,
 659                 .strategy       = &sysctl_intvec,
 660                 .extra1         = &minolduid,
 661                 .extra2         = &maxolduid,
 662         },
 663         {
 664                 .ctl_name       = KERN_OVERFLOWGID,
 665                 .procname       = "overflowgid",
 666                 .data           = &overflowgid,
 667                 .maxlen         = sizeof(int),
 668                 .mode           = 0644,
 669                 .proc_handler   = &proc_dointvec_minmax,
 670                 .strategy       = &sysctl_intvec,
 671                 .extra1         = &minolduid,
 672                 .extra2         = &maxolduid,
 673         },
 674 #ifdef CONFIG_S390
 675 #ifdef CONFIG_MATHEMU
 676         {
 677                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 678                 .procname       = "ieee_emulation_warnings",
 679                 .data           = &sysctl_ieee_emulation_warnings,
 680                 .maxlen         = sizeof(int),
 681                 .mode           = 0644,
 682                 .proc_handler   = &proc_dointvec,
 683         },
 684 #endif
 685         {
 686                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 687                 .procname       = "userprocess_debug",
 688                 .data           = &sysctl_userprocess_debug,
 689                 .maxlen         = sizeof(int),
 690                 .mode           = 0644,
 691                 .proc_handler   = &proc_dointvec,
 692         },
 693 #endif
 694         {
 695                 .ctl_name       = KERN_PIDMAX,
 696                 .procname       = "pid_max",
 697                 .data           = &pid_max,
 698                 .maxlen         = sizeof (int),
 699                 .mode           = 0644,
 700                 .proc_handler   = &proc_dointvec_minmax,
 701                 .strategy       = sysctl_intvec,
 702                 .extra1         = &pid_max_min,
 703                 .extra2         = &pid_max_max,
 704         },
 705         {
 706                 .ctl_name       = KERN_PANIC_ON_OOPS,
 707                 .procname       = "panic_on_oops",
 708                 .data           = &panic_on_oops,
 709                 .maxlen         = sizeof(int),
 710                 .mode           = 0644,
 711                 .proc_handler   = &proc_dointvec,
 712         },
 713 #if defined CONFIG_PRINTK
 714         {
 715                 .ctl_name       = KERN_PRINTK,
 716                 .procname       = "printk",
 717                 .data           = &console_loglevel,
 718                 .maxlen         = 4*sizeof(int),
 719                 .mode           = 0644,
 720                 .proc_handler   = &proc_dointvec,
 721         },
 722         {
 723                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 724                 .procname       = "printk_ratelimit",
 725                 .data           = &printk_ratelimit_state.interval,
 726                 .maxlen         = sizeof(int),
 727                 .mode           = 0644,
 728                 .proc_handler   = &proc_dointvec_jiffies,
 729                 .strategy       = &sysctl_jiffies,
 730         },
 731         {
 732                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 733                 .procname       = "printk_ratelimit_burst",
 734                 .data           = &printk_ratelimit_state.burst,
 735                 .maxlen         = sizeof(int),
 736                 .mode           = 0644,
 737                 .proc_handler   = &proc_dointvec,
 738         },
 739         {
 740                 .ctl_name       = CTL_UNNUMBERED,
 741                 .procname       = "printk_delay",
 742                 .data           = &printk_delay_msec,
 743                 .maxlen         = sizeof(int),
 744                 .mode           = 0644,
 745                 .proc_handler   = &proc_dointvec_minmax,
 746                 .strategy       = &sysctl_intvec,
 747                 .extra1         = &zero,
 748                 .extra2         = &ten_thousand,
 749         },
 750 #endif
 751         {
 752                 .ctl_name       = KERN_NGROUPS_MAX,
 753                 .procname       = "ngroups_max",
 754                 .data           = &ngroups_max,
 755                 .maxlen         = sizeof (int),
 756                 .mode           = 0444,
 757                 .proc_handler   = &proc_dointvec,
 758         },
 759 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 760         {
 761                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 762                 .procname       = "unknown_nmi_panic",
 763                 .data           = &unknown_nmi_panic,
 764                 .maxlen         = sizeof (int),
 765                 .mode           = 0644,
 766                 .proc_handler   = &proc_dointvec,
 767         },
 768         {
 769                 .procname       = "nmi_watchdog",
 770                 .data           = &nmi_watchdog_enabled,
 771                 .maxlen         = sizeof (int),
 772                 .mode           = 0644,
 773                 .proc_handler   = &proc_nmi_enabled,
 774         },
 775 #endif
 776 #if defined(CONFIG_X86)
 777         {
 778                 .ctl_name       = KERN_PANIC_ON_NMI,
 779                 .procname       = "panic_on_unrecovered_nmi",
 780                 .data           = &panic_on_unrecovered_nmi,
 781                 .maxlen         = sizeof(int),
 782                 .mode           = 0644,
 783                 .proc_handler   = &proc_dointvec,
 784         },
 785         {
 786                 .ctl_name       = CTL_UNNUMBERED,
 787                 .procname       = "panic_on_io_nmi",
 788                 .data           = &panic_on_io_nmi,
 789                 .maxlen         = sizeof(int),
 790                 .mode           = 0644,
 791                 .proc_handler   = &proc_dointvec,
 792         },
 793         {
 794                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 795                 .procname       = "bootloader_type",
 796                 .data           = &bootloader_type,
 797                 .maxlen         = sizeof (int),
 798                 .mode           = 0444,
 799                 .proc_handler   = &proc_dointvec,
 800         },
 801         {
 802                 .ctl_name       = CTL_UNNUMBERED,
 803                 .procname       = "bootloader_version",
 804                 .data           = &bootloader_version,
 805                 .maxlen         = sizeof (int),
 806                 .mode           = 0444,
 807                 .proc_handler   = &proc_dointvec,
 808         },
 809         {
 810                 .ctl_name       = CTL_UNNUMBERED,
 811                 .procname       = "kstack_depth_to_print",
 812                 .data           = &kstack_depth_to_print,
 813                 .maxlen         = sizeof(int),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dointvec,
 816         },
 817         {
 818                 .ctl_name       = CTL_UNNUMBERED,
 819                 .procname       = "io_delay_type",
 820                 .data           = &io_delay_type,
 821                 .maxlen         = sizeof(int),
 822                 .mode           = 0644,
 823                 .proc_handler   = &proc_dointvec,
 824         },
 825 #endif
 826 #if defined(CONFIG_MMU)
 827         {
 828                 .ctl_name       = KERN_RANDOMIZE,
 829                 .procname       = "randomize_va_space",
 830                 .data           = &randomize_va_space,
 831                 .maxlen         = sizeof(int),
 832                 .mode           = 0644,
 833                 .proc_handler   = &proc_dointvec,
 834         },
 835 #endif
 836 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 837         {
 838                 .ctl_name       = KERN_SPIN_RETRY,
 839                 .procname       = "spin_retry",
 840                 .data           = &spin_retry,
 841                 .maxlen         = sizeof (int),
 842                 .mode           = 0644,
 843                 .proc_handler   = &proc_dointvec,
 844         },
 845 #endif
 846 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 847         {
 848                 .procname       = "acpi_video_flags",
 849                 .data           = &acpi_realmode_flags,
 850                 .maxlen         = sizeof (unsigned long),
 851                 .mode           = 0644,
 852                 .proc_handler   = &proc_doulongvec_minmax,
 853         },
 854 #endif
 855 #ifdef CONFIG_IA64
 856         {
 857                 .ctl_name       = KERN_IA64_UNALIGNED,
 858                 .procname       = "ignore-unaligned-usertrap",
 859                 .data           = &no_unaligned_warning,
 860                 .maxlen         = sizeof (int),
 861                 .mode           = 0644,
 862                 .proc_handler   = &proc_dointvec,
 863         },
 864         {
 865                 .ctl_name       = CTL_UNNUMBERED,
 866                 .procname       = "unaligned-dump-stack",
 867                 .data           = &unaligned_dump_stack,
 868                 .maxlen         = sizeof (int),
 869                 .mode           = 0644,
 870                 .proc_handler   = &proc_dointvec,
 871         },
 872 #endif
 873 #ifdef CONFIG_DETECT_SOFTLOCKUP
 874         {
 875                 .ctl_name       = CTL_UNNUMBERED,
 876                 .procname       = "softlockup_panic",
 877                 .data           = &softlockup_panic,
 878                 .maxlen         = sizeof(int),
 879                 .mode           = 0644,
 880                 .proc_handler   = &proc_dointvec_minmax,
 881                 .strategy       = &sysctl_intvec,
 882                 .extra1         = &zero,
 883                 .extra2         = &one,
 884         },
 885         {
 886                 .ctl_name       = CTL_UNNUMBERED,
 887                 .procname       = "softlockup_thresh",
 888                 .data           = &softlockup_thresh,
 889                 .maxlen         = sizeof(int),
 890                 .mode           = 0644,
 891                 .proc_handler   = &proc_dosoftlockup_thresh,
 892                 .strategy       = &sysctl_intvec,
 893                 .extra1         = &neg_one,
 894                 .extra2         = &sixty,
 895         },
 896 #endif
 897 #ifdef CONFIG_DETECT_HUNG_TASK
 898         {
 899                 .ctl_name       = CTL_UNNUMBERED,
 900                 .procname       = "hung_task_panic",
 901                 .data           = &sysctl_hung_task_panic,
 902                 .maxlen         = sizeof(int),
 903                 .mode           = 0644,
 904                 .proc_handler   = &proc_dointvec_minmax,
 905                 .strategy       = &sysctl_intvec,
 906                 .extra1         = &zero,
 907                 .extra2         = &one,
 908         },
 909         {
 910                 .ctl_name       = CTL_UNNUMBERED,
 911                 .procname       = "hung_task_check_count",
 912                 .data           = &sysctl_hung_task_check_count,
 913                 .maxlen         = sizeof(unsigned long),
 914                 .mode           = 0644,
 915                 .proc_handler   = &proc_doulongvec_minmax,
 916                 .strategy       = &sysctl_intvec,
 917         },
 918         {
 919                 .ctl_name       = CTL_UNNUMBERED,
 920                 .procname       = "hung_task_timeout_secs",
 921                 .data           = &sysctl_hung_task_timeout_secs,
 922                 .maxlen         = sizeof(unsigned long),
 923                 .mode           = 0644,
 924                 .proc_handler   = &proc_dohung_task_timeout_secs,
 925                 .strategy       = &sysctl_intvec,
 926         },
 927         {
 928                 .ctl_name       = CTL_UNNUMBERED,
 929                 .procname       = "hung_task_warnings",
 930                 .data           = &sysctl_hung_task_warnings,
 931                 .maxlen         = sizeof(unsigned long),
 932                 .mode           = 0644,
 933                 .proc_handler   = &proc_doulongvec_minmax,
 934                 .strategy       = &sysctl_intvec,
 935         },
 936 #endif
 937 #ifdef CONFIG_COMPAT
 938         {
 939                 .ctl_name       = KERN_COMPAT_LOG,
 940                 .procname       = "compat-log",
 941                 .data           = &compat_log,
 942                 .maxlen         = sizeof (int),
 943                 .mode           = 0644,
 944                 .proc_handler   = &proc_dointvec,
 945         },
 946 #endif
 947 #ifdef CONFIG_RT_MUTEXES
 948         {
 949                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 950                 .procname       = "max_lock_depth",
 951                 .data           = &max_lock_depth,
 952                 .maxlen         = sizeof(int),
 953                 .mode           = 0644,
 954                 .proc_handler   = &proc_dointvec,
 955         },
 956 #endif
 957         {
 958                 .ctl_name       = CTL_UNNUMBERED,
 959                 .procname       = "poweroff_cmd",
 960                 .data           = &poweroff_cmd,
 961                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 962                 .mode           = 0644,
 963                 .proc_handler   = &proc_dostring,
 964                 .strategy       = &sysctl_string,
 965         },
 966 #ifdef CONFIG_KEYS
 967         {
 968                 .ctl_name       = CTL_UNNUMBERED,
 969                 .procname       = "keys",
 970                 .mode           = 0555,
 971                 .child          = key_sysctls,
 972         },
 973 #endif
 974 #ifdef CONFIG_RCU_TORTURE_TEST
 975         {
 976                 .ctl_name       = CTL_UNNUMBERED,
 977                 .procname       = "rcutorture_runnable",
 978                 .data           = &rcutorture_runnable,
 979                 .maxlen         = sizeof(int),
 980                 .mode           = 0644,
 981                 .proc_handler   = &proc_dointvec,
 982         },
 983 #endif
 984 #ifdef CONFIG_SLOW_WORK
 985         {
 986                 .ctl_name       = CTL_UNNUMBERED,
 987                 .procname       = "slow-work",
 988                 .mode           = 0555,
 989                 .child          = slow_work_sysctls,
 990         },
 991 #endif
 992 #ifdef CONFIG_PERF_EVENTS
 993         {
 994                 .ctl_name       = CTL_UNNUMBERED,
 995                 .procname       = "perf_event_paranoid",
 996                 .data           = &sysctl_perf_event_paranoid,
 997                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 998                 .mode           = 0644,
 999                 .proc_handler   = &proc_dointvec,
1000         },
1001         {
1002                 .ctl_name       = CTL_UNNUMBERED,
1003                 .procname       = "perf_event_mlock_kb",
1004                 .data           = &sysctl_perf_event_mlock,
1005                 .maxlen         = sizeof(sysctl_perf_event_mlock),
1006                 .mode           = 0644,
1007                 .proc_handler   = &proc_dointvec,
1008         },
1009         {
1010                 .ctl_name       = CTL_UNNUMBERED,
1011                 .procname       = "perf_event_max_sample_rate",
1012                 .data           = &sysctl_perf_event_sample_rate,
1013                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
1014                 .mode           = 0644,
1015                 .proc_handler   = &proc_dointvec,
1016         },
1017 #endif
1018 #ifdef CONFIG_KMEMCHECK
1019         {
1020                 .ctl_name       = CTL_UNNUMBERED,
1021                 .procname       = "kmemcheck",
1022                 .data           = &kmemcheck_enabled,
1023                 .maxlen         = sizeof(int),
1024                 .mode           = 0644,
1025                 .proc_handler   = &proc_dointvec,
1026         },
1027 #endif
1028 #ifdef CONFIG_BLOCK
1029         {
1030                 .ctl_name       = CTL_UNNUMBERED,
1031                 .procname       = "blk_iopoll",
1032                 .data           = &blk_iopoll_enabled,
1033                 .maxlen         = sizeof(int),
1034                 .mode           = 0644,
1035                 .proc_handler   = &proc_dointvec,
1036         },
1037 #endif
1038 /*
1039  * NOTE: do not add new entries to this table unless you have read
1040  * Documentation/sysctl/ctl_unnumbered.txt
1041  */
1042         { .ctl_name = 0 }
1043 };
1044
1045 static struct ctl_table vm_table[] = {
1046         {
1047                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
1048                 .procname       = "overcommit_memory",
1049                 .data           = &sysctl_overcommit_memory,
1050                 .maxlen         = sizeof(sysctl_overcommit_memory),
1051                 .mode           = 0644,
1052                 .proc_handler   = &proc_dointvec,
1053         },
1054         {
1055                 .ctl_name       = VM_PANIC_ON_OOM,
1056                 .procname       = "panic_on_oom",
1057                 .data           = &sysctl_panic_on_oom,
1058                 .maxlen         = sizeof(sysctl_panic_on_oom),
1059                 .mode           = 0644,
1060                 .proc_handler   = &proc_dointvec,
1061         },
1062         {
1063                 .ctl_name       = CTL_UNNUMBERED,
1064                 .procname       = "oom_kill_allocating_task",
1065                 .data           = &sysctl_oom_kill_allocating_task,
1066                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1067                 .mode           = 0644,
1068                 .proc_handler   = &proc_dointvec,
1069         },
1070         {
1071                 .ctl_name       = CTL_UNNUMBERED,
1072                 .procname       = "oom_dump_tasks",
1073                 .data           = &sysctl_oom_dump_tasks,
1074                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1075                 .mode           = 0644,
1076                 .proc_handler   = &proc_dointvec,
1077         },
1078         {
1079                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1080                 .procname       = "overcommit_ratio",
1081                 .data           = &sysctl_overcommit_ratio,
1082                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1083                 .mode           = 0644,
1084                 .proc_handler   = &proc_dointvec,
1085         },
1086         {
1087                 .ctl_name       = VM_PAGE_CLUSTER,
1088                 .procname       = "page-cluster",
1089                 .data           = &page_cluster,
1090                 .maxlen         = sizeof(int),
1091                 .mode           = 0644,
1092                 .proc_handler   = &proc_dointvec,
1093         },
1094         {
1095                 .ctl_name       = VM_DIRTY_BACKGROUND,
1096                 .procname       = "dirty_background_ratio",
1097                 .data           = &dirty_background_ratio,
1098                 .maxlen         = sizeof(dirty_background_ratio),
1099                 .mode           = 0644,
1100                 .proc_handler   = &dirty_background_ratio_handler,
1101                 .strategy       = &sysctl_intvec,
1102                 .extra1         = &zero,
1103                 .extra2         = &one_hundred,
1104         },
1105         {
1106                 .ctl_name       = CTL_UNNUMBERED,
1107                 .procname       = "dirty_background_bytes",
1108                 .data           = &dirty_background_bytes,
1109                 .maxlen         = sizeof(dirty_background_bytes),
1110                 .mode           = 0644,
1111                 .proc_handler   = &dirty_background_bytes_handler,
1112                 .strategy       = &sysctl_intvec,
1113                 .extra1         = &one_ul,
1114         },
1115         {
1116                 .ctl_name       = VM_DIRTY_RATIO,
1117                 .procname       = "dirty_ratio",
1118                 .data           = &vm_dirty_ratio,
1119                 .maxlen         = sizeof(vm_dirty_ratio),
1120                 .mode           = 0644,
1121                 .proc_handler   = &dirty_ratio_handler,
1122                 .strategy       = &sysctl_intvec,
1123                 .extra1         = &zero,
1124                 .extra2         = &one_hundred,
1125         },
1126         {
1127                 .ctl_name       = CTL_UNNUMBERED,
1128                 .procname       = "dirty_bytes",
1129                 .data           = &vm_dirty_bytes,
1130                 .maxlen         = sizeof(vm_dirty_bytes),
1131                 .mode           = 0644,
1132                 .proc_handler   = &dirty_bytes_handler,
1133                 .strategy       = &sysctl_intvec,
1134                 .extra1         = &dirty_bytes_min,
1135         },
1136         {
1137                 .procname       = "dirty_writeback_centisecs",
1138                 .data           = &dirty_writeback_interval,
1139                 .maxlen         = sizeof(dirty_writeback_interval),
1140                 .mode           = 0644,
1141                 .proc_handler   = &dirty_writeback_centisecs_handler,
1142         },
1143         {
1144                 .procname       = "dirty_expire_centisecs",
1145                 .data           = &dirty_expire_interval,
1146                 .maxlen         = sizeof(dirty_expire_interval),
1147                 .mode           = 0644,
1148                 .proc_handler   = &proc_dointvec,
1149         },
1150         {
1151                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1152                 .procname       = "nr_pdflush_threads",
1153                 .data           = &nr_pdflush_threads,
1154                 .maxlen         = sizeof nr_pdflush_threads,
1155                 .mode           = 0444 /* read-only*/,
1156                 .proc_handler   = &proc_dointvec,
1157         },
1158         {
1159                 .ctl_name       = VM_SWAPPINESS,
1160                 .procname       = "swappiness",
1161                 .data           = &vm_swappiness,
1162                 .maxlen         = sizeof(vm_swappiness),
1163                 .mode           = 0644,
1164                 .proc_handler   = &proc_dointvec_minmax,
1165                 .strategy       = &sysctl_intvec,
1166                 .extra1         = &zero,
1167                 .extra2         = &one_hundred,
1168         },
1169 #ifdef CONFIG_HUGETLB_PAGE
1170          {
1171                 .procname       = "nr_hugepages",
1172                 .data           = NULL,
1173                 .maxlen         = sizeof(unsigned long),
1174                 .mode           = 0644,
1175                 .proc_handler   = &hugetlb_sysctl_handler,
1176                 .extra1         = (void *)&hugetlb_zero,
1177                 .extra2         = (void *)&hugetlb_infinity,
1178          },
1179          {
1180                 .ctl_name       = VM_HUGETLB_GROUP,
1181                 .procname       = "hugetlb_shm_group",
1182                 .data           = &sysctl_hugetlb_shm_group,
1183                 .maxlen         = sizeof(gid_t),
1184                 .mode           = 0644,
1185                 .proc_handler   = &proc_dointvec,
1186          },
1187          {
1188                 .ctl_name       = CTL_UNNUMBERED,
1189                 .procname       = "hugepages_treat_as_movable",
1190                 .data           = &hugepages_treat_as_movable,
1191                 .maxlen         = sizeof(int),
1192                 .mode           = 0644,
1193                 .proc_handler   = &hugetlb_treat_movable_handler,
1194         },
1195         {
1196                 .ctl_name       = CTL_UNNUMBERED,
1197                 .procname       = "nr_overcommit_hugepages",
1198                 .data           = NULL,
1199                 .maxlen         = sizeof(unsigned long),
1200                 .mode           = 0644,
1201                 .proc_handler   = &hugetlb_overcommit_handler,
1202                 .extra1         = (void *)&hugetlb_zero,
1203                 .extra2         = (void *)&hugetlb_infinity,
1204         },
1205 #endif
1206         {
1207                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1208                 .procname       = "lowmem_reserve_ratio",
1209                 .data           = &sysctl_lowmem_reserve_ratio,
1210                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1211                 .mode           = 0644,
1212                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1213                 .strategy       = &sysctl_intvec,
1214         },
1215         {
1216                 .ctl_name       = VM_DROP_PAGECACHE,
1217                 .procname       = "drop_caches",
1218                 .data           = &sysctl_drop_caches,
1219                 .maxlen         = sizeof(int),
1220                 .mode           = 0644,
1221                 .proc_handler   = drop_caches_sysctl_handler,
1222                 .strategy       = &sysctl_intvec,
1223         },
1224         {
1225                 .ctl_name       = VM_MIN_FREE_KBYTES,
1226                 .procname       = "min_free_kbytes",
1227                 .data           = &min_free_kbytes,
1228                 .maxlen         = sizeof(min_free_kbytes),
1229                 .mode           = 0644,
1230                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1231                 .strategy       = &sysctl_intvec,
1232                 .extra1         = &zero,
1233         },
1234         {
1235                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1236                 .procname       = "percpu_pagelist_fraction",
1237                 .data           = &percpu_pagelist_fraction,
1238                 .maxlen         = sizeof(percpu_pagelist_fraction),
1239                 .mode           = 0644,
1240                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1241                 .strategy       = &sysctl_intvec,
1242                 .extra1         = &min_percpu_pagelist_fract,
1243         },
1244 #ifdef CONFIG_MMU
1245         {
1246                 .ctl_name       = VM_MAX_MAP_COUNT,
1247                 .procname       = "max_map_count",
1248                 .data           = &sysctl_max_map_count,
1249                 .maxlen         = sizeof(sysctl_max_map_count),
1250                 .mode           = 0644,
1251                 .proc_handler   = &proc_dointvec
1252         },
1253 #else
1254         {
1255                 .ctl_name       = CTL_UNNUMBERED,
1256                 .procname       = "nr_trim_pages",
1257                 .data           = &sysctl_nr_trim_pages,
1258                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1259                 .mode           = 0644,
1260                 .proc_handler   = &proc_dointvec_minmax,
1261                 .strategy       = &sysctl_intvec,
1262                 .extra1         = &zero,
1263         },
1264 #endif
1265         {
1266                 .ctl_name       = VM_LAPTOP_MODE,
1267                 .procname       = "laptop_mode",
1268                 .data           = &laptop_mode,
1269                 .maxlen         = sizeof(laptop_mode),
1270                 .mode           = 0644,
1271                 .proc_handler   = &proc_dointvec_jiffies,
1272                 .strategy       = &sysctl_jiffies,
1273         },
1274         {
1275                 .ctl_name       = VM_BLOCK_DUMP,
1276                 .procname       = "block_dump",
1277                 .data           = &block_dump,
1278                 .maxlen         = sizeof(block_dump),
1279                 .mode           = 0644,
1280                 .proc_handler   = &proc_dointvec,
1281                 .strategy       = &sysctl_intvec,
1282                 .extra1         = &zero,
1283         },
1284         {
1285                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1286                 .procname       = "vfs_cache_pressure",
1287                 .data           = &sysctl_vfs_cache_pressure,
1288                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1289                 .mode           = 0644,
1290                 .proc_handler   = &proc_dointvec,
1291                 .strategy       = &sysctl_intvec,
1292                 .extra1         = &zero,
1293         },
1294 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1295         {
1296                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1297                 .procname       = "legacy_va_layout",
1298                 .data           = &sysctl_legacy_va_layout,
1299                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1300                 .mode           = 0644,
1301                 .proc_handler   = &proc_dointvec,
1302                 .strategy       = &sysctl_intvec,
1303                 .extra1         = &zero,
1304         },
1305 #endif
1306 #ifdef CONFIG_NUMA
1307         {
1308                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1309                 .procname       = "zone_reclaim_mode",
1310                 .data           = &zone_reclaim_mode,
1311                 .maxlen         = sizeof(zone_reclaim_mode),
1312                 .mode           = 0644,
1313                 .proc_handler   = &proc_dointvec,
1314                 .strategy       = &sysctl_intvec,
1315                 .extra1         = &zero,
1316         },
1317         {
1318                 .ctl_name       = VM_MIN_UNMAPPED,
1319                 .procname       = "min_unmapped_ratio",
1320                 .data           = &sysctl_min_unmapped_ratio,
1321                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1322                 .mode           = 0644,
1323                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1324                 .strategy       = &sysctl_intvec,
1325                 .extra1         = &zero,
1326                 .extra2         = &one_hundred,
1327         },
1328         {
1329                 .ctl_name       = VM_MIN_SLAB,
1330                 .procname       = "min_slab_ratio",
1331                 .data           = &sysctl_min_slab_ratio,
1332                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1333                 .mode           = 0644,
1334                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1335                 .strategy       = &sysctl_intvec,
1336                 .extra1         = &zero,
1337                 .extra2         = &one_hundred,
1338         },
1339 #endif
1340 #ifdef CONFIG_SMP
1341         {
1342                 .ctl_name       = CTL_UNNUMBERED,
1343                 .procname       = "stat_interval",
1344                 .data           = &sysctl_stat_interval,
1345                 .maxlen         = sizeof(sysctl_stat_interval),
1346                 .mode           = 0644,
1347                 .proc_handler   = &proc_dointvec_jiffies,
1348                 .strategy       = &sysctl_jiffies,
1349         },
1350 #endif
1351         {
1352                 .ctl_name       = CTL_UNNUMBERED,
1353                 .procname       = "mmap_min_addr",
1354                 .data           = &dac_mmap_min_addr,
1355                 .maxlen         = sizeof(unsigned long),
1356                 .mode           = 0644,
1357                 .proc_handler   = &mmap_min_addr_handler,
1358         },
1359 #ifdef CONFIG_NUMA
1360         {
1361                 .ctl_name       = CTL_UNNUMBERED,
1362                 .procname       = "numa_zonelist_order",
1363                 .data           = &numa_zonelist_order,
1364                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1365                 .mode           = 0644,
1366                 .proc_handler   = &numa_zonelist_order_handler,
1367                 .strategy       = &sysctl_string,
1368         },
1369 #endif
1370 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1371    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1372         {
1373                 .ctl_name       = VM_VDSO_ENABLED,
1374                 .procname       = "vdso_enabled",
1375                 .data           = &vdso_enabled,
1376                 .maxlen         = sizeof(vdso_enabled),
1377                 .mode           = 0644,
1378                 .proc_handler   = &proc_dointvec,
1379                 .strategy       = &sysctl_intvec,
1380                 .extra1         = &zero,
1381         },
1382 #endif
1383 #ifdef CONFIG_HIGHMEM
1384         {
1385                 .ctl_name       = CTL_UNNUMBERED,
1386                 .procname       = "highmem_is_dirtyable",
1387                 .data           = &vm_highmem_is_dirtyable,
1388                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1389                 .mode           = 0644,
1390                 .proc_handler   = &proc_dointvec_minmax,
1391                 .strategy       = &sysctl_intvec,
1392                 .extra1         = &zero,
1393                 .extra2         = &one,
1394         },
1395 #endif
1396         {
1397                 .ctl_name       = CTL_UNNUMBERED,
1398                 .procname       = "scan_unevictable_pages",
1399                 .data           = &scan_unevictable_pages,
1400                 .maxlen         = sizeof(scan_unevictable_pages),
1401                 .mode           = 0644,
1402                 .proc_handler   = &scan_unevictable_handler,
1403         },
1404 #ifdef CONFIG_MEMORY_FAILURE
1405         {
1406                 .ctl_name       = CTL_UNNUMBERED,
1407                 .procname       = "memory_failure_early_kill",
1408                 .data           = &sysctl_memory_failure_early_kill,
1409                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1410                 .mode           = 0644,
1411                 .proc_handler   = &proc_dointvec_minmax,
1412                 .strategy       = &sysctl_intvec,
1413                 .extra1         = &zero,
1414                 .extra2         = &one,
1415         },
1416         {
1417                 .ctl_name       = CTL_UNNUMBERED,
1418                 .procname       = "memory_failure_recovery",
1419                 .data           = &sysctl_memory_failure_recovery,
1420                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1421                 .mode           = 0644,
1422                 .proc_handler   = &proc_dointvec_minmax,
1423                 .strategy       = &sysctl_intvec,
1424                 .extra1         = &zero,
1425                 .extra2         = &one,
1426         },
1427 #endif
1428
1429 /*
1430  * NOTE: do not add new entries to this table unless you have read
1431  * Documentation/sysctl/ctl_unnumbered.txt
1432  */
1433         { .ctl_name = 0 }
1434 };
1435
1436 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1437 static struct ctl_table binfmt_misc_table[] = {
1438         { .ctl_name = 0 }
1439 };
1440 #endif
1441
1442 static struct ctl_table fs_table[] = {
1443         {
1444                 .ctl_name       = FS_NRINODE,
1445                 .procname       = "inode-nr",
1446                 .data           = &inodes_stat,
1447                 .maxlen         = 2*sizeof(int),
1448                 .mode           = 0444,
1449                 .proc_handler   = &proc_dointvec,
1450         },
1451         {
1452                 .ctl_name       = FS_STATINODE,
1453                 .procname       = "inode-state",
1454                 .data           = &inodes_stat,
1455                 .maxlen         = 7*sizeof(int),
1456                 .mode           = 0444,
1457                 .proc_handler   = &proc_dointvec,
1458         },
1459         {
1460                 .procname       = "file-nr",
1461                 .data           = &files_stat,
1462                 .maxlen         = 3*sizeof(int),
1463                 .mode           = 0444,
1464                 .proc_handler   = &proc_nr_files,
1465         },
1466         {
1467                 .ctl_name       = FS_MAXFILE,
1468                 .procname       = "file-max",
1469                 .data           = &files_stat.max_files,
1470                 .maxlen         = sizeof(int),
1471                 .mode           = 0644,
1472                 .proc_handler   = &proc_dointvec,
1473         },
1474         {
1475                 .ctl_name       = CTL_UNNUMBERED,
1476                 .procname       = "nr_open",
1477                 .data           = &sysctl_nr_open,
1478                 .maxlen         = sizeof(int),
1479                 .mode           = 0644,
1480                 .proc_handler   = &proc_dointvec_minmax,
1481                 .extra1         = &sysctl_nr_open_min,
1482                 .extra2         = &sysctl_nr_open_max,
1483         },
1484         {
1485                 .ctl_name       = FS_DENTRY,
1486                 .procname       = "dentry-state",
1487                 .data           = &dentry_stat,
1488                 .maxlen         = 6*sizeof(int),
1489                 .mode           = 0444,
1490                 .proc_handler   = &proc_dointvec,
1491         },
1492         {
1493                 .ctl_name       = FS_OVERFLOWUID,
1494                 .procname       = "overflowuid",
1495                 .data           = &fs_overflowuid,
1496                 .maxlen         = sizeof(int),
1497                 .mode           = 0644,
1498                 .proc_handler   = &proc_dointvec_minmax,
1499                 .strategy       = &sysctl_intvec,
1500                 .extra1         = &minolduid,
1501                 .extra2         = &maxolduid,
1502         },
1503         {
1504                 .ctl_name       = FS_OVERFLOWGID,
1505                 .procname       = "overflowgid",
1506                 .data           = &fs_overflowgid,
1507                 .maxlen         = sizeof(int),
1508                 .mode           = 0644,
1509                 .proc_handler   = &proc_dointvec_minmax,
1510                 .strategy       = &sysctl_intvec,
1511                 .extra1         = &minolduid,
1512                 .extra2         = &maxolduid,
1513         },
1514 #ifdef CONFIG_FILE_LOCKING
1515         {
1516                 .ctl_name       = FS_LEASES,
1517                 .procname       = "leases-enable",
1518                 .data           = &leases_enable,
1519                 .maxlen         = sizeof(int),
1520                 .mode           = 0644,
1521                 .proc_handler   = &proc_dointvec,
1522         },
1523 #endif
1524 #ifdef CONFIG_DNOTIFY
1525         {
1526                 .ctl_name       = FS_DIR_NOTIFY,
1527                 .procname       = "dir-notify-enable",
1528                 .data           = &dir_notify_enable,
1529                 .maxlen         = sizeof(int),
1530                 .mode           = 0644,
1531                 .proc_handler   = &proc_dointvec,
1532         },
1533 #endif
1534 #ifdef CONFIG_MMU
1535 #ifdef CONFIG_FILE_LOCKING
1536         {
1537                 .ctl_name       = FS_LEASE_TIME,
1538                 .procname       = "lease-break-time",
1539                 .data           = &lease_break_time,
1540                 .maxlen         = sizeof(int),
1541                 .mode           = 0644,
1542                 .proc_handler   = &proc_dointvec,
1543         },
1544 #endif
1545 #ifdef CONFIG_AIO
1546         {
1547                 .procname       = "aio-nr",
1548                 .data           = &aio_nr,
1549                 .maxlen         = sizeof(aio_nr),
1550                 .mode           = 0444,
1551                 .proc_handler   = &proc_doulongvec_minmax,
1552         },
1553         {
1554                 .procname       = "aio-max-nr",
1555                 .data           = &aio_max_nr,
1556                 .maxlen         = sizeof(aio_max_nr),
1557                 .mode           = 0644,
1558                 .proc_handler   = &proc_doulongvec_minmax,
1559         },
1560 #endif /* CONFIG_AIO */
1561 #ifdef CONFIG_INOTIFY_USER
1562         {
1563                 .ctl_name       = FS_INOTIFY,
1564                 .procname       = "inotify",
1565                 .mode           = 0555,
1566                 .child          = inotify_table,
1567         },
1568 #endif
1569 #ifdef CONFIG_EPOLL
1570         {
1571                 .procname       = "epoll",
1572                 .mode           = 0555,
1573                 .child          = epoll_table,
1574         },
1575 #endif
1576 #endif
1577         {
1578                 .ctl_name       = KERN_SETUID_DUMPABLE,
1579                 .procname       = "suid_dumpable",
1580                 .data           = &suid_dumpable,
1581                 .maxlen         = sizeof(int),
1582                 .mode           = 0644,
1583                 .proc_handler   = &proc_dointvec_minmax,
1584                 .strategy       = &sysctl_intvec,
1585                 .extra1         = &zero,
1586                 .extra2         = &two,
1587         },
1588 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1589         {
1590                 .ctl_name       = CTL_UNNUMBERED,
1591                 .procname       = "binfmt_misc",
1592                 .mode           = 0555,
1593                 .child          = binfmt_misc_table,
1594         },
1595 #endif
1596 /*
1597  * NOTE: do not add new entries to this table unless you have read
1598  * Documentation/sysctl/ctl_unnumbered.txt
1599  */
1600         { .ctl_name = 0 }
1601 };
1602
1603 static struct ctl_table debug_table[] = {
1604 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1605         {
1606                 .ctl_name       = CTL_UNNUMBERED,
1607                 .procname       = "exception-trace",
1608                 .data           = &show_unhandled_signals,
1609                 .maxlen         = sizeof(int),
1610                 .mode           = 0644,
1611                 .proc_handler   = proc_dointvec
1612         },
1613 #endif
1614         { .ctl_name = 0 }
1615 };
1616
1617 static struct ctl_table dev_table[] = {
1618         { .ctl_name = 0 }
1619 };
1620
1621 static DEFINE_SPINLOCK(sysctl_lock);
1622
1623 /* called under sysctl_lock */
1624 static int use_table(struct ctl_table_header *p)
1625 {
1626         if (unlikely(p->unregistering))
1627                 return 0;
1628         p->used++;
1629         return 1;
1630 }
1631
1632 /* called under sysctl_lock */
1633 static void unuse_table(struct ctl_table_header *p)
1634 {
1635         if (!--p->used)
1636                 if (unlikely(p->unregistering))
1637                         complete(p->unregistering);
1638 }
1639
1640 /* called under sysctl_lock, will reacquire if has to wait */
1641 static void start_unregistering(struct ctl_table_header *p)
1642 {
1643         /*
1644          * if p->used is 0, nobody will ever touch that entry again;
1645          * we'll eliminate all paths to it before dropping sysctl_lock
1646          */
1647         if (unlikely(p->used)) {
1648                 struct completion wait;
1649                 init_completion(&wait);
1650                 p->unregistering = &wait;
1651                 spin_unlock(&sysctl_lock);
1652                 wait_for_completion(&wait);
1653                 spin_lock(&sysctl_lock);
1654         } else {
1655                 /* anything non-NULL; we'll never dereference it */
1656                 p->unregistering = ERR_PTR(-EINVAL);
1657         }
1658         /*
1659          * do not remove from the list until nobody holds it; walking the
1660          * list in do_sysctl() relies on that.
1661          */
1662         list_del_init(&p->ctl_entry);
1663 }
1664
1665 void sysctl_head_get(struct ctl_table_header *head)
1666 {
1667         spin_lock(&sysctl_lock);
1668         head->count++;
1669         spin_unlock(&sysctl_lock);
1670 }
1671
1672 void sysctl_head_put(struct ctl_table_header *head)
1673 {
1674         spin_lock(&sysctl_lock);
1675         if (!--head->count)
1676                 kfree(head);
1677         spin_unlock(&sysctl_lock);
1678 }
1679
1680 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1681 {
1682         if (!head)
1683                 BUG();
1684         spin_lock(&sysctl_lock);
1685         if (!use_table(head))
1686                 head = ERR_PTR(-ENOENT);
1687         spin_unlock(&sysctl_lock);
1688         return head;
1689 }
1690
1691 void sysctl_head_finish(struct ctl_table_header *head)
1692 {
1693         if (!head)
1694                 return;
1695         spin_lock(&sysctl_lock);
1696         unuse_table(head);
1697         spin_unlock(&sysctl_lock);
1698 }
1699
1700 static struct ctl_table_set *
1701 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1702 {
1703         struct ctl_table_set *set = &root->default_set;
1704         if (root->lookup)
1705                 set = root->lookup(root, namespaces);
1706         return set;
1707 }
1708
1709 static struct list_head *
1710 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1711 {
1712         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1713         return &set->list;
1714 }
1715
1716 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1717                                             struct ctl_table_header *prev)
1718 {
1719         struct ctl_table_root *root;
1720         struct list_head *header_list;
1721         struct ctl_table_header *head;
1722         struct list_head *tmp;
1723
1724         spin_lock(&sysctl_lock);
1725         if (prev) {
1726                 head = prev;
1727                 tmp = &prev->ctl_entry;
1728                 unuse_table(prev);
1729                 goto next;
1730         }
1731         tmp = &root_table_header.ctl_entry;
1732         for (;;) {
1733                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1734
1735                 if (!use_table(head))
1736                         goto next;
1737                 spin_unlock(&sysctl_lock);
1738                 return head;
1739         next:
1740                 root = head->root;
1741                 tmp = tmp->next;
1742                 header_list = lookup_header_list(root, namespaces);
1743                 if (tmp != header_list)
1744                         continue;
1745
1746                 do {
1747                         root = list_entry(root->root_list.next,
1748                                         struct ctl_table_root, root_list);
1749                         if (root == &sysctl_table_root)
1750                                 goto out;
1751                         header_list = lookup_header_list(root, namespaces);
1752                 } while (list_empty(header_list));
1753                 tmp = header_list->next;
1754         }
1755 out:
1756         spin_unlock(&sysctl_lock);
1757         return NULL;
1758 }
1759
1760 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1761 {
1762         return __sysctl_head_next(current->nsproxy, prev);
1763 }
1764
1765 void register_sysctl_root(struct ctl_table_root *root)
1766 {
1767         spin_lock(&sysctl_lock);
1768         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1769         spin_unlock(&sysctl_lock);
1770 }
1771
1772 #ifdef CONFIG_SYSCTL_SYSCALL
1773 /* Perform the actual read/write of a sysctl table entry. */
1774 static int do_sysctl_strategy(struct ctl_table_root *root,
1775                         struct ctl_table *table,
1776                         void __user *oldval, size_t __user *oldlenp,
1777                         void __user *newval, size_t newlen)
1778 {
1779         int op = 0, rc;
1780
1781         if (oldval)
1782                 op |= MAY_READ;
1783         if (newval)
1784                 op |= MAY_WRITE;
1785         if (sysctl_perm(root, table, op))
1786                 return -EPERM;
1787
1788         if (table->strategy) {
1789                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1790                 if (rc < 0)
1791                         return rc;
1792                 if (rc > 0)
1793                         return 0;
1794         }
1795
1796         /* If there is no strategy routine, or if the strategy returns
1797          * zero, proceed with automatic r/w */
1798         if (table->data && table->maxlen) {
1799                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1800                 if (rc < 0)
1801                         return rc;
1802         }
1803         return 0;
1804 }
1805
1806 static int parse_table(int __user *name, int nlen,
1807                        void __user *oldval, size_t __user *oldlenp,
1808                        void __user *newval, size_t newlen,
1809                        struct ctl_table_root *root,
1810                        struct ctl_table *table)
1811 {
1812         int n;
1813 repeat:
1814         if (!nlen)
1815                 return -ENOTDIR;
1816         if (get_user(n, name))
1817                 return -EFAULT;
1818         for ( ; table->ctl_name || table->procname; table++) {
1819                 if (!table->ctl_name)
1820                         continue;
1821                 if (n == table->ctl_name) {
1822                         int error;
1823                         if (table->child) {
1824                                 if (sysctl_perm(root, table, MAY_EXEC))
1825                                         return -EPERM;
1826                                 name++;
1827                                 nlen--;
1828                                 table = table->child;
1829                                 goto repeat;
1830                         }
1831                         error = do_sysctl_strategy(root, table,
1832                                                    oldval, oldlenp,
1833                                                    newval, newlen);
1834                         return error;
1835                 }
1836         }
1837         return -ENOTDIR;
1838 }
1839
1840 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1841                void __user *newval, size_t newlen)
1842 {
1843         struct ctl_table_header *head;
1844         int error = -ENOTDIR;
1845
1846         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1847                 return -ENOTDIR;
1848         if (oldval) {
1849                 int old_len;
1850                 if (!oldlenp || get_user(old_len, oldlenp))
1851                         return -EFAULT;
1852         }
1853
1854         for (head = sysctl_head_next(NULL); head;
1855                         head = sysctl_head_next(head)) {
1856                 error = parse_table(name, nlen, oldval, oldlenp,
1857                                         newval, newlen,
1858                                         head->root, head->ctl_table);
1859                 if (error != -ENOTDIR) {
1860                         sysctl_head_finish(head);
1861                         break;
1862                 }
1863         }
1864         return error;
1865 }
1866
1867 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1868 {
1869         struct __sysctl_args tmp;
1870         int error;
1871
1872         if (copy_from_user(&tmp, args, sizeof(tmp)))
1873                 return -EFAULT;
1874
1875         error = deprecated_sysctl_warning(&tmp);
1876         if (error)
1877                 goto out;
1878
1879         lock_kernel();
1880         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1881                           tmp.newval, tmp.newlen);
1882         unlock_kernel();
1883 out:
1884         return error;
1885 }
1886 #endif /* CONFIG_SYSCTL_SYSCALL */
1887
1888 /*
1889  * sysctl_perm does NOT grant the superuser all rights automatically, because
1890  * some sysctl variables are readonly even to root.
1891  */
1892
1893 static int test_perm(int mode, int op)
1894 {
1895         if (!current_euid())
1896                 mode >>= 6;
1897         else if (in_egroup_p(0))
1898                 mode >>= 3;
1899         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1900                 return 0;
1901         return -EACCES;
1902 }
1903
1904 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1905 {
1906         int error;
1907         int mode;
1908
1909         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1910         if (error)
1911                 return error;
1912
1913         if (root->permissions)
1914                 mode = root->permissions(root, current->nsproxy, table);
1915         else
1916                 mode = table->mode;
1917
1918         return test_perm(mode, op);
1919 }
1920
1921 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1922 {
1923         for (; table->ctl_name || table->procname; table++) {
1924                 table->parent = parent;
1925                 if (table->child)
1926                         sysctl_set_parent(table, table->child);
1927         }
1928 }
1929
1930 static __init int sysctl_init(void)
1931 {
1932         sysctl_set_parent(NULL, root_table);
1933 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1934         {
1935                 int err;
1936                 err = sysctl_check_table(current->nsproxy, root_table);
1937         }
1938 #endif
1939         return 0;
1940 }
1941
1942 core_initcall(sysctl_init);
1943
1944 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1945                                       struct ctl_table *table)
1946 {
1947         struct ctl_table *p;
1948         const char *s = branch->procname;
1949
1950         /* branch should have named subdirectory as its first element */
1951         if (!s || !branch->child)
1952                 return NULL;
1953
1954         /* ... and nothing else */
1955         if (branch[1].procname || branch[1].ctl_name)
1956                 return NULL;
1957
1958         /* table should contain subdirectory with the same name */
1959         for (p = table; p->procname || p->ctl_name; p++) {
1960                 if (!p->child)
1961                         continue;
1962                 if (p->procname && strcmp(p->procname, s) == 0)
1963                         return p;
1964         }
1965         return NULL;
1966 }
1967
1968 /* see if attaching q to p would be an improvement */
1969 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1970 {
1971         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1972         struct ctl_table *next;
1973         int is_better = 0;
1974         int not_in_parent = !p->attached_by;
1975
1976         while ((next = is_branch_in(by, to)) != NULL) {
1977                 if (by == q->attached_by)
1978                         is_better = 1;
1979                 if (to == p->attached_by)
1980                         not_in_parent = 1;
1981                 by = by->child;
1982                 to = next->child;
1983         }
1984
1985         if (is_better && not_in_parent) {
1986                 q->attached_by = by;
1987                 q->attached_to = to;
1988                 q->parent = p;
1989         }
1990 }
1991
1992 /**
1993  * __register_sysctl_paths - register a sysctl hierarchy
1994  * @root: List of sysctl headers to register on
1995  * @namespaces: Data to compute which lists of sysctl entries are visible
1996  * @path: The path to the directory the sysctl table is in.
1997  * @table: the top-level table structure
1998  *
1999  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2000  * array. A completely 0 filled entry terminates the table.
2001  *
2002  * The members of the &struct ctl_table structure are used as follows:
2003  *
2004  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
2005  *            must be unique within that level of sysctl
2006  *
2007  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
2008  *            enter a sysctl file
2009  *
2010  * data - a pointer to data for use by proc_handler
2011  *
2012  * maxlen - the maximum size in bytes of the data
2013  *
2014  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
2015  *
2016  * child - a pointer to the child sysctl table if this entry is a directory, or
2017  *         %NULL.
2018  *
2019  * proc_handler - the text handler routine (described below)
2020  *
2021  * strategy - the strategy routine (described below)
2022  *
2023  * de - for internal use by the sysctl routines
2024  *
2025  * extra1, extra2 - extra pointers usable by the proc handler routines
2026  *
2027  * Leaf nodes in the sysctl tree will be represented by a single file
2028  * under /proc; non-leaf nodes will be represented by directories.
2029  *
2030  * sysctl(2) can automatically manage read and write requests through
2031  * the sysctl table.  The data and maxlen fields of the ctl_table
2032  * struct enable minimal validation of the values being written to be
2033  * performed, and the mode field allows minimal authentication.
2034  *
2035  * More sophisticated management can be enabled by the provision of a
2036  * strategy routine with the table entry.  This will be called before
2037  * any automatic read or write of the data is performed.
2038  *
2039  * The strategy routine may return
2040  *
2041  * < 0 - Error occurred (error is passed to user process)
2042  *
2043  * 0   - OK - proceed with automatic read or write.
2044  *
2045  * > 0 - OK - read or write has been done by the strategy routine, so
2046  *       return immediately.
2047  *
2048  * There must be a proc_handler routine for any terminal nodes
2049  * mirrored under /proc/sys (non-terminals are handled by a built-in
2050  * directory handler).  Several default handlers are available to
2051  * cover common cases -
2052  *
2053  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
2054  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
2055  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
2056  *
2057  * It is the handler's job to read the input buffer from user memory
2058  * and process it. The handler should return 0 on success.
2059  *
2060  * This routine returns %NULL on a failure to register, and a pointer
2061  * to the table header on success.
2062  */
2063 struct ctl_table_header *__register_sysctl_paths(
2064         struct ctl_table_root *root,
2065         struct nsproxy *namespaces,
2066         const struct ctl_path *path, struct ctl_table *table)
2067 {
2068         struct ctl_table_header *header;
2069         struct ctl_table *new, **prevp;
2070         unsigned int n, npath;
2071         struct ctl_table_set *set;
2072
2073         /* Count the path components */
2074         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2075                 ;
2076
2077         /*
2078          * For each path component, allocate a 2-element ctl_table array.
2079          * The first array element will be filled with the sysctl entry
2080          * for this, the second will be the sentinel (ctl_name == 0).
2081          *
2082          * We allocate everything in one go so that we don't have to
2083          * worry about freeing additional memory in unregister_sysctl_table.
2084          */
2085         header = kzalloc(sizeof(struct ctl_table_header) +
2086                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2087         if (!header)
2088                 return NULL;
2089
2090         new = (struct ctl_table *) (header + 1);
2091
2092         /* Now connect the dots */
2093         prevp = &header->ctl_table;
2094         for (n = 0; n < npath; ++n, ++path) {
2095                 /* Copy the procname */
2096                 new->procname = path->procname;
2097                 new->ctl_name = path->ctl_name;
2098                 new->mode     = 0555;
2099
2100                 *prevp = new;
2101                 prevp = &new->child;
2102
2103                 new += 2;
2104         }
2105         *prevp = table;
2106         header->ctl_table_arg = table;
2107
2108         INIT_LIST_HEAD(&header->ctl_entry);
2109         header->used = 0;
2110         header->unregistering = NULL;
2111         header->root = root;
2112         sysctl_set_parent(NULL, header->ctl_table);
2113         header->count = 1;
2114 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2115         if (sysctl_check_table(namespaces, header->ctl_table)) {
2116                 kfree(header);
2117                 return NULL;
2118         }
2119 #endif
2120         spin_lock(&sysctl_lock);
2121         header->set = lookup_header_set(root, namespaces);
2122         header->attached_by = header->ctl_table;
2123         header->attached_to = root_table;
2124         header->parent = &root_table_header;
2125         for (set = header->set; set; set = set->parent) {
2126                 struct ctl_table_header *p;
2127                 list_for_each_entry(p, &set->list, ctl_entry) {
2128                         if (p->unregistering)
2129                                 continue;
2130                         try_attach(p, header);
2131                 }
2132         }
2133         header->parent->count++;
2134         list_add_tail(&header->ctl_entry, &header->set->list);
2135         spin_unlock(&sysctl_lock);
2136
2137         return header;
2138 }
2139
2140 /**
2141  * register_sysctl_table_path - register a sysctl table hierarchy
2142  * @path: The path to the directory the sysctl table is in.
2143  * @table: the top-level table structure
2144  *
2145  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2146  * array. A completely 0 filled entry terminates the table.
2147  *
2148  * See __register_sysctl_paths for more details.
2149  */
2150 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2151                                                 struct ctl_table *table)
2152 {
2153         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2154                                         path, table);
2155 }
2156
2157 /**
2158  * register_sysctl_table - register a sysctl table hierarchy
2159  * @table: the top-level table structure
2160  *
2161  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2162  * array. A completely 0 filled entry terminates the table.
2163  *
2164  * See register_sysctl_paths for more details.
2165  */
2166 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2167 {
2168         static const struct ctl_path null_path[] = { {} };
2169
2170         return register_sysctl_paths(null_path, table);
2171 }
2172
2173 /**
2174  * unregister_sysctl_table - unregister a sysctl table hierarchy
2175  * @header: the header returned from register_sysctl_table
2176  *
2177  * Unregisters the sysctl table and all children. proc entries may not
2178  * actually be removed until they are no longer used by anyone.
2179  */
2180 void unregister_sysctl_table(struct ctl_table_header * header)
2181 {
2182         might_sleep();
2183
2184         if (header == NULL)
2185                 return;
2186
2187         spin_lock(&sysctl_lock);
2188         start_unregistering(header);
2189         if (!--header->parent->count) {
2190                 WARN_ON(1);
2191                 kfree(header->parent);
2192         }
2193         if (!--header->count)
2194                 kfree(header);
2195         spin_unlock(&sysctl_lock);
2196 }
2197
2198 int sysctl_is_seen(struct ctl_table_header *p)
2199 {
2200         struct ctl_table_set *set = p->set;
2201         int res;
2202         spin_lock(&sysctl_lock);
2203         if (p->unregistering)
2204                 res = 0;
2205         else if (!set->is_seen)
2206                 res = 1;
2207         else
2208                 res = set->is_seen(set);
2209         spin_unlock(&sysctl_lock);
2210         return res;
2211 }
2212
2213 void setup_sysctl_set(struct ctl_table_set *p,
2214         struct ctl_table_set *parent,
2215         int (*is_seen)(struct ctl_table_set *))
2216 {
2217         INIT_LIST_HEAD(&p->list);
2218         p->parent = parent ? parent : &sysctl_table_root.default_set;
2219         p->is_seen = is_seen;
2220 }
2221
2222 #else /* !CONFIG_SYSCTL */
2223 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2224 {
2225         return NULL;
2226 }
2227
2228 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2229                                                     struct ctl_table *table)
2230 {
2231         return NULL;
2232 }
2233
2234 void unregister_sysctl_table(struct ctl_table_header * table)
2235 {
2236 }
2237
2238 void setup_sysctl_set(struct ctl_table_set *p,
2239         struct ctl_table_set *parent,
2240         int (*is_seen)(struct ctl_table_set *))
2241 {
2242 }
2243
2244 void sysctl_head_put(struct ctl_table_header *head)
2245 {
2246 }
2247
2248 #endif /* CONFIG_SYSCTL */
2249
2250 /*
2251  * /proc/sys support
2252  */
2253
2254 #ifdef CONFIG_PROC_SYSCTL
2255
2256 static int _proc_do_string(void* data, int maxlen, int write,
2257                            void __user *buffer,
2258                            size_t *lenp, loff_t *ppos)
2259 {
2260         size_t len;
2261         char __user *p;
2262         char c;
2263
2264         if (!data || !maxlen || !*lenp) {
2265                 *lenp = 0;
2266                 return 0;
2267         }
2268
2269         if (write) {
2270                 len = 0;
2271                 p = buffer;
2272                 while (len < *lenp) {
2273                         if (get_user(c, p++))
2274                                 return -EFAULT;
2275                         if (c == 0 || c == '\n')
2276                                 break;
2277                         len++;
2278                 }
2279                 if (len >= maxlen)
2280                         len = maxlen-1;
2281                 if(copy_from_user(data, buffer, len))
2282                         return -EFAULT;
2283                 ((char *) data)[len] = 0;
2284                 *ppos += *lenp;
2285         } else {
2286                 len = strlen(data);
2287                 if (len > maxlen)
2288                         len = maxlen;
2289
2290                 if (*ppos > len) {
2291                         *lenp = 0;
2292                         return 0;
2293                 }
2294
2295                 data += *ppos;
2296                 len  -= *ppos;
2297
2298                 if (len > *lenp)
2299                         len = *lenp;
2300                 if (len)
2301                         if(copy_to_user(buffer, data, len))
2302                                 return -EFAULT;
2303                 if (len < *lenp) {
2304                         if(put_user('\n', ((char __user *) buffer) + len))
2305                                 return -EFAULT;
2306                         len++;
2307                 }
2308                 *lenp = len;
2309                 *ppos += len;
2310         }
2311         return 0;
2312 }
2313
2314 /**
2315  * proc_dostring - read a string sysctl
2316  * @table: the sysctl table
2317  * @write: %TRUE if this is a write to the sysctl file
2318  * @buffer: the user buffer
2319  * @lenp: the size of the user buffer
2320  * @ppos: file position
2321  *
2322  * Reads/writes a string from/to the user buffer. If the kernel
2323  * buffer provided is not large enough to hold the string, the
2324  * string is truncated. The copied string is %NULL-terminated.
2325  * If the string is being read by the user process, it is copied
2326  * and a newline '\n' is added. It is truncated if the buffer is
2327  * not large enough.
2328  *
2329  * Returns 0 on success.
2330  */
2331 int proc_dostring(struct ctl_table *table, int write,
2332                   void __user *buffer, size_t *lenp, loff_t *ppos)
2333 {
2334         return _proc_do_string(table->data, table->maxlen, write,
2335                                buffer, lenp, ppos);
2336 }
2337
2338
2339 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2340                                  int *valp,
2341                                  int write, void *data)
2342 {
2343         if (write) {
2344                 *valp = *negp ? -*lvalp : *lvalp;
2345         } else {
2346                 int val = *valp;
2347                 if (val < 0) {
2348                         *negp = -1;
2349                         *lvalp = (unsigned long)-val;
2350                 } else {
2351                         *negp = 0;
2352                         *lvalp = (unsigned long)val;
2353                 }
2354         }
2355         return 0;
2356 }
2357
2358 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2359                   int write, void __user *buffer,
2360                   size_t *lenp, loff_t *ppos,
2361                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2362                               int write, void *data),
2363                   void *data)
2364 {
2365 #define TMPBUFLEN 21
2366         int *i, vleft, first = 1, neg;
2367         unsigned long lval;
2368         size_t left, len;
2369
2370         char buf[TMPBUFLEN], *p;
2371         char __user *s = buffer;
2372
2373         if (!tbl_data || !table->maxlen || !*lenp ||
2374             (*ppos && !write)) {
2375                 *lenp = 0;
2376                 return 0;
2377         }
2378
2379         i = (int *) tbl_data;
2380         vleft = table->maxlen / sizeof(*i);
2381         left = *lenp;
2382
2383         if (!conv)
2384                 conv = do_proc_dointvec_conv;
2385
2386         for (; left && vleft--; i++, first=0) {
2387                 if (write) {
2388                         while (left) {
2389                                 char c;
2390                                 if (get_user(c, s))
2391                                         return -EFAULT;
2392                                 if (!isspace(c))
2393                                         break;
2394                                 left--;
2395                                 s++;
2396                         }
2397                         if (!left)
2398                                 break;
2399                         neg = 0;
2400                         len = left;
2401                         if (len > sizeof(buf) - 1)
2402                                 len = sizeof(buf) - 1;
2403                         if (copy_from_user(buf, s, len))
2404                                 return -EFAULT;
2405                         buf[len] = 0;
2406                         p = buf;
2407                         if (*p == '-' && left > 1) {
2408                                 neg = 1;
2409                                 p++;
2410                         }
2411                         if (*p < '0' || *p > '9')
2412                                 break;
2413
2414                         lval = simple_strtoul(p, &p, 0);
2415
2416                         len = p-buf;
2417                         if ((len < left) && *p && !isspace(*p))
2418                                 break;
2419                         s += len;
2420                         left -= len;
2421
2422                         if (conv(&neg, &lval, i, 1, data))
2423                                 break;
2424                 } else {
2425                         p = buf;
2426                         if (!first)
2427                                 *p++ = '\t';
2428
2429                         if (conv(&neg, &lval, i, 0, data))
2430                                 break;
2431
2432                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2433                         len = strlen(buf);
2434                         if (len > left)
2435                                 len = left;
2436                         if(copy_to_user(s, buf, len))
2437                                 return -EFAULT;
2438                         left -= len;
2439                         s += len;
2440                 }
2441         }
2442
2443         if (!write && !first && left) {
2444                 if(put_user('\n', s))
2445                         return -EFAULT;
2446                 left--, s++;
2447         }
2448         if (write) {
2449                 while (left) {
2450                         char c;
2451                         if (get_user(c, s++))
2452                                 return -EFAULT;
2453                         if (!isspace(c))
2454                                 break;
2455                         left--;
2456                 }
2457         }
2458         if (write && first)
2459                 return -EINVAL;
2460         *lenp -= left;
2461         *ppos += *lenp;
2462         return 0;
2463 #undef TMPBUFLEN
2464 }
2465
2466 static int do_proc_dointvec(struct ctl_table *table, int write,
2467                   void __user *buffer, size_t *lenp, loff_t *ppos,
2468                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2469                               int write, void *data),
2470                   void *data)
2471 {
2472         return __do_proc_dointvec(table->data, table, write,
2473                         buffer, lenp, ppos, conv, data);
2474 }
2475
2476 /**
2477  * proc_dointvec - read a vector of integers
2478  * @table: the sysctl table
2479  * @write: %TRUE if this is a write to the sysctl file
2480  * @buffer: the user buffer
2481  * @lenp: the size of the user buffer
2482  * @ppos: file position
2483  *
2484  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2485  * values from/to the user buffer, treated as an ASCII string.
2486  *
2487  * Returns 0 on success.
2488  */
2489 int proc_dointvec(struct ctl_table *table, int write,
2490                      void __user *buffer, size_t *lenp, loff_t *ppos)
2491 {
2492     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2493                             NULL,NULL);
2494 }
2495
2496 /*
2497  * Taint values can only be increased
2498  * This means we can safely use a temporary.
2499  */
2500 static int proc_taint(struct ctl_table *table, int write,
2501                                void __user *buffer, size_t *lenp, loff_t *ppos)
2502 {
2503         struct ctl_table t;
2504         unsigned long tmptaint = get_taint();
2505         int err;
2506
2507         if (write && !capable(CAP_SYS_ADMIN))
2508                 return -EPERM;
2509
2510         t = *table;
2511         t.data = &tmptaint;
2512         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2513         if (err < 0)
2514                 return err;
2515
2516         if (write) {
2517                 /*
2518                  * Poor man's atomic or. Not worth adding a primitive
2519                  * to everyone's atomic.h for this
2520                  */
2521                 int i;
2522                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2523                         if ((tmptaint >> i) & 1)
2524                                 add_taint(i);
2525                 }
2526         }
2527
2528         return err;
2529 }
2530
2531 struct do_proc_dointvec_minmax_conv_param {
2532         int *min;
2533         int *max;
2534 };
2535
2536 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2537                                         int *valp,
2538                                         int write, void *data)
2539 {
2540         struct do_proc_dointvec_minmax_conv_param *param = data;
2541         if (write) {
2542                 int val = *negp ? -*lvalp : *lvalp;
2543                 if ((param->min && *param->min > val) ||
2544                     (param->max && *param->max < val))
2545                         return -EINVAL;
2546                 *valp = val;
2547         } else {
2548                 int val = *valp;
2549                 if (val < 0) {
2550                         *negp = -1;
2551                         *lvalp = (unsigned long)-val;
2552                 } else {
2553                         *negp = 0;
2554                         *lvalp = (unsigned long)val;
2555                 }
2556         }
2557         return 0;
2558 }
2559
2560 /**
2561  * proc_dointvec_minmax - read a vector of integers with min/max values
2562  * @table: the sysctl table
2563  * @write: %TRUE if this is a write to the sysctl file
2564  * @buffer: the user buffer
2565  * @lenp: the size of the user buffer
2566  * @ppos: file position
2567  *
2568  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2569  * values from/to the user buffer, treated as an ASCII string.
2570  *
2571  * This routine will ensure the values are within the range specified by
2572  * table->extra1 (min) and table->extra2 (max).
2573  *
2574  * Returns 0 on success.
2575  */
2576 int proc_dointvec_minmax(struct ctl_table *table, int write,
2577                   void __user *buffer, size_t *lenp, loff_t *ppos)
2578 {
2579         struct do_proc_dointvec_minmax_conv_param param = {
2580                 .min = (int *) table->extra1,
2581                 .max = (int *) table->extra2,
2582         };
2583         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2584                                 do_proc_dointvec_minmax_conv, &param);
2585 }
2586
2587 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2588                                      void __user *buffer,
2589                                      size_t *lenp, loff_t *ppos,
2590                                      unsigned long convmul,
2591                                      unsigned long convdiv)
2592 {
2593 #define TMPBUFLEN 21
2594         unsigned long *i, *min, *max, val;
2595         int vleft, first=1, neg;
2596         size_t len, left;
2597         char buf[TMPBUFLEN], *p;
2598         char __user *s = buffer;
2599
2600         if (!data || !table->maxlen || !*lenp ||
2601             (*ppos && !write)) {
2602                 *lenp = 0;
2603                 return 0;
2604         }
2605
2606         i = (unsigned long *) data;
2607         min = (unsigned long *) table->extra1;
2608         max = (unsigned long *) table->extra2;
2609         vleft = table->maxlen / sizeof(unsigned long);
2610         left = *lenp;
2611
2612         for (; left && vleft--; i++, min++, max++, first=0) {
2613                 if (write) {
2614                         while (left) {
2615                                 char c;
2616                                 if (get_user(c, s))
2617                                         return -EFAULT;
2618                                 if (!isspace(c))
2619                                         break;
2620                                 left--;
2621                                 s++;
2622                         }
2623                         if (!left)
2624                                 break;
2625                         neg = 0;
2626                         len = left;
2627                         if (len > TMPBUFLEN-1)
2628                                 len = TMPBUFLEN-1;
2629                         if (copy_from_user(buf, s, len))
2630                                 return -EFAULT;
2631                         buf[len] = 0;
2632                         p = buf;
2633                         if (*p == '-' && left > 1) {
2634                                 neg = 1;
2635                                 p++;
2636                         }
2637                         if (*p < '0' || *p > '9')
2638                                 break;
2639                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2640                         len = p-buf;
2641                         if ((len < left) && *p && !isspace(*p))
2642                                 break;
2643                         if (neg)
2644                                 val = -val;
2645                         s += len;
2646                         left -= len;
2647
2648                         if(neg)
2649                                 continue;
2650                         if ((min && val < *min) || (max && val > *max))
2651                                 continue;
2652                         *i = val;
2653                 } else {
2654                         p = buf;
2655                         if (!first)
2656                                 *p++ = '\t';
2657                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2658                         len = strlen(buf);
2659                         if (len > left)
2660                                 len = left;
2661                         if(copy_to_user(s, buf, len))
2662                                 return -EFAULT;
2663                         left -= len;
2664                         s += len;
2665                 }
2666         }
2667
2668         if (!write && !first && left) {
2669                 if(put_user('\n', s))
2670                         return -EFAULT;
2671                 left--, s++;
2672         }
2673         if (write) {
2674                 while (left) {
2675                         char c;
2676                         if (get_user(c, s++))
2677                                 return -EFAULT;
2678                         if (!isspace(c))
2679                                 break;
2680                         left--;
2681                 }
2682         }
2683         if (write && first)
2684                 return -EINVAL;
2685         *lenp -= left;
2686         *ppos += *lenp;
2687         return 0;
2688 #undef TMPBUFLEN
2689 }
2690
2691 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2692                                      void __user *buffer,
2693                                      size_t *lenp, loff_t *ppos,
2694                                      unsigned long convmul,
2695                                      unsigned long convdiv)
2696 {
2697         return __do_proc_doulongvec_minmax(table->data, table, write,
2698                         buffer, lenp, ppos, convmul, convdiv);
2699 }
2700
2701 /**
2702  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2703  * @table: the sysctl table
2704  * @write: %TRUE if this is a write to the sysctl file
2705  * @buffer: the user buffer
2706  * @lenp: the size of the user buffer
2707  * @ppos: file position
2708  *
2709  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2710  * values from/to the user buffer, treated as an ASCII string.
2711  *
2712  * This routine will ensure the values are within the range specified by
2713  * table->extra1 (min) and table->extra2 (max).
2714  *
2715  * Returns 0 on success.
2716  */
2717 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2718                            void __user *buffer, size_t *lenp, loff_t *ppos)
2719 {
2720     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2721 }
2722
2723 /**
2724  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2725  * @table: the sysctl table
2726  * @write: %TRUE if this is a write to the sysctl file
2727  * @buffer: the user buffer
2728  * @lenp: the size of the user buffer
2729  * @ppos: file position
2730  *
2731  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2732  * values from/to the user buffer, treated as an ASCII string. The values
2733  * are treated as milliseconds, and converted to jiffies when they are stored.
2734  *
2735  * This routine will ensure the values are within the range specified by
2736  * table->extra1 (min) and table->extra2 (max).
2737  *
2738  * Returns 0 on success.
2739  */
2740 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2741                                       void __user *buffer,
2742                                       size_t *lenp, loff_t *ppos)
2743 {
2744     return do_proc_doulongvec_minmax(table, write, buffer,
2745                                      lenp, ppos, HZ, 1000l);
2746 }
2747
2748
2749 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2750                                          int *valp,
2751                                          int write, void *data)
2752 {
2753         if (write) {
2754                 if (*lvalp > LONG_MAX / HZ)
2755                         return 1;
2756                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2757         } else {
2758                 int val = *valp;
2759                 unsigned long lval;
2760                 if (val < 0) {
2761                         *negp = -1;
2762                         lval = (unsigned long)-val;
2763                 } else {
2764                         *negp = 0;
2765                         lval = (unsigned long)val;
2766                 }
2767                 *lvalp = lval / HZ;
2768         }
2769         return 0;
2770 }
2771
2772 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2773                                                 int *valp,
2774                                                 int write, void *data)
2775 {
2776         if (write) {
2777                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2778                         return 1;
2779                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2780         } else {
2781                 int val = *valp;
2782                 unsigned long lval;
2783                 if (val < 0) {
2784                         *negp = -1;
2785                         lval = (unsigned long)-val;
2786                 } else {
2787                         *negp = 0;
2788                         lval = (unsigned long)val;
2789                 }
2790                 *lvalp = jiffies_to_clock_t(lval);
2791         }
2792         return 0;
2793 }
2794
2795 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2796                                             int *valp,
2797                                             int write, void *data)
2798 {
2799         if (write) {
2800                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2801         } else {
2802                 int val = *valp;
2803                 unsigned long lval;
2804                 if (val < 0) {
2805                         *negp = -1;
2806                         lval = (unsigned long)-val;
2807                 } else {
2808                         *negp = 0;
2809                         lval = (unsigned long)val;
2810                 }
2811                 *lvalp = jiffies_to_msecs(lval);
2812         }
2813         return 0;
2814 }
2815
2816 /**
2817  * proc_dointvec_jiffies - read a vector of integers as seconds
2818  * @table: the sysctl table
2819  * @write: %TRUE if this is a write to the sysctl file
2820  * @buffer: the user buffer
2821  * @lenp: the size of the user buffer
2822  * @ppos: file position
2823  *
2824  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2825  * values from/to the user buffer, treated as an ASCII string.
2826  * The values read are assumed to be in seconds, and are converted into
2827  * jiffies.
2828  *
2829  * Returns 0 on success.
2830  */
2831 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2832                           void __user *buffer, size_t *lenp, loff_t *ppos)
2833 {
2834     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2835                             do_proc_dointvec_jiffies_conv,NULL);
2836 }
2837
2838 /**
2839  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2840  * @table: the sysctl table
2841  * @write: %TRUE if this is a write to the sysctl file
2842  * @buffer: the user buffer
2843  * @lenp: the size of the user buffer
2844  * @ppos: pointer to the file position
2845  *
2846  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2847  * values from/to the user buffer, treated as an ASCII string.
2848  * The values read are assumed to be in 1/USER_HZ seconds, and
2849  * are converted into jiffies.
2850  *
2851  * Returns 0 on success.
2852  */
2853 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2854                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2855 {
2856     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2857                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2858 }
2859
2860 /**
2861  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2862  * @table: the sysctl table
2863  * @write: %TRUE if this is a write to the sysctl file
2864  * @buffer: the user buffer
2865  * @lenp: the size of the user buffer
2866  * @ppos: file position
2867  * @ppos: the current position in the file
2868  *
2869  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2870  * values from/to the user buffer, treated as an ASCII string.
2871  * The values read are assumed to be in 1/1000 seconds, and
2872  * are converted into jiffies.
2873  *
2874  * Returns 0 on success.
2875  */
2876 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2877                              void __user *buffer, size_t *lenp, loff_t *ppos)
2878 {
2879         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2880                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2881 }
2882
2883 static int proc_do_cad_pid(struct ctl_table *table, int write,
2884                            void __user *buffer, size_t *lenp, loff_t *ppos)
2885 {
2886         struct pid *new_pid;
2887         pid_t tmp;
2888         int r;
2889
2890         tmp = pid_vnr(cad_pid);
2891
2892         r = __do_proc_dointvec(&tmp, table, write, buffer,
2893                                lenp, ppos, NULL, NULL);
2894         if (r || !write)
2895                 return r;
2896
2897         new_pid = find_get_pid(tmp);
2898         if (!new_pid)
2899                 return -ESRCH;
2900
2901         put_pid(xchg(&cad_pid, new_pid));
2902         return 0;
2903 }
2904
2905 #else /* CONFIG_PROC_FS */
2906
2907 int proc_dostring(struct ctl_table *table, int write,
2908                   void __user *buffer, size_t *lenp, loff_t *ppos)
2909 {
2910         return -ENOSYS;
2911 }
2912
2913 int proc_dointvec(struct ctl_table *table, int write,
2914                   void __user *buffer, size_t *lenp, loff_t *ppos)
2915 {
2916         return -ENOSYS;
2917 }
2918
2919 int proc_dointvec_minmax(struct ctl_table *table, int write,
2920                     void __user *buffer, size_t *lenp, loff_t *ppos)
2921 {
2922         return -ENOSYS;
2923 }
2924
2925 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2926                     void __user *buffer, size_t *lenp, loff_t *ppos)
2927 {
2928         return -ENOSYS;
2929 }
2930
2931 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2932                     void __user *buffer, size_t *lenp, loff_t *ppos)
2933 {
2934         return -ENOSYS;
2935 }
2936
2937 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2938                              void __user *buffer, size_t *lenp, loff_t *ppos)
2939 {
2940         return -ENOSYS;
2941 }
2942
2943 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2944                     void __user *buffer, size_t *lenp, loff_t *ppos)
2945 {
2946         return -ENOSYS;
2947 }
2948
2949 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2950                                       void __user *buffer,
2951                                       size_t *lenp, loff_t *ppos)
2952 {
2953     return -ENOSYS;
2954 }
2955
2956
2957 #endif /* CONFIG_PROC_FS */
2958
2959
2960 #ifdef CONFIG_SYSCTL_SYSCALL
2961 /*
2962  * General sysctl support routines
2963  */
2964
2965 /* The generic sysctl data routine (used if no strategy routine supplied) */
2966 int sysctl_data(struct ctl_table *table,
2967                 void __user *oldval, size_t __user *oldlenp,
2968                 void __user *newval, size_t newlen)
2969 {
2970         size_t len;
2971
2972         /* Get out of I don't have a variable */
2973         if (!table->data || !table->maxlen)
2974                 return -ENOTDIR;
2975
2976         if (oldval && oldlenp) {
2977                 if (get_user(len, oldlenp))
2978                         return -EFAULT;
2979                 if (len) {
2980                         if (len > table->maxlen)
2981                                 len = table->maxlen;
2982                         if (copy_to_user(oldval, table->data, len))
2983                                 return -EFAULT;
2984                         if (put_user(len, oldlenp))
2985                                 return -EFAULT;
2986                 }
2987         }
2988
2989         if (newval && newlen) {
2990                 if (newlen > table->maxlen)
2991                         newlen = table->maxlen;
2992
2993                 if (copy_from_user(table->data, newval, newlen))
2994                         return -EFAULT;
2995         }
2996         return 1;
2997 }
2998
2999 /* The generic string strategy routine: */
3000 int sysctl_string(struct ctl_table *table,
3001                   void __user *oldval, size_t __user *oldlenp,
3002                   void __user *newval, size_t newlen)
3003 {
3004         if (!table->data || !table->maxlen)
3005                 return -ENOTDIR;
3006
3007         if (oldval && oldlenp) {
3008                 size_t bufsize;
3009                 if (get_user(bufsize, oldlenp))
3010                         return -EFAULT;
3011                 if (bufsize) {
3012                         size_t len = strlen(table->data), copied;
3013
3014                         /* This shouldn't trigger for a well-formed sysctl */
3015                         if (len > table->maxlen)
3016                                 len = table->maxlen;
3017
3018                         /* Copy up to a max of bufsize-1 bytes of the string */
3019                         copied = (len >= bufsize) ? bufsize - 1 : len;
3020
3021                         if (copy_to_user(oldval, table->data, copied) ||
3022                             put_user(0, (char __user *)(oldval + copied)))
3023                                 return -EFAULT;
3024                         if (put_user(len, oldlenp))
3025                                 return -EFAULT;
3026                 }
3027         }
3028         if (newval && newlen) {
3029                 size_t len = newlen;
3030                 if (len > table->maxlen)
3031                         len = table->maxlen;
3032                 if(copy_from_user(table->data, newval, len))
3033                         return -EFAULT;
3034                 if (len == table->maxlen)
3035                         len--;
3036                 ((char *) table->data)[len] = 0;
3037         }
3038         return 1;
3039 }
3040
3041 /*
3042  * This function makes sure that all of the integers in the vector
3043  * are between the minimum and maximum values given in the arrays
3044  * table->extra1 and table->extra2, respectively.
3045  */
3046 int sysctl_intvec(struct ctl_table *table,
3047                 void __user *oldval, size_t __user *oldlenp,
3048                 void __user *newval, size_t newlen)
3049 {
3050
3051         if (newval && newlen) {
3052                 int __user *vec = (int __user *) newval;
3053                 int *min = (int *) table->extra1;
3054                 int *max = (int *) table->extra2;
3055                 size_t length;
3056                 int i;
3057
3058                 if (newlen % sizeof(int) != 0)
3059                         return -EINVAL;
3060
3061                 if (!table->extra1 && !table->extra2)
3062                         return 0;
3063
3064                 if (newlen > table->maxlen)
3065                         newlen = table->maxlen;
3066                 length = newlen / sizeof(int);
3067
3068                 for (i = 0; i < length; i++) {
3069                         int value;
3070                         if (get_user(value, vec + i))
3071                                 return -EFAULT;
3072                         if (min && value < min[i])
3073                                 return -EINVAL;
3074                         if (max && value > max[i])
3075                                 return -EINVAL;
3076                 }
3077         }
3078         return 0;
3079 }
3080
3081 /* Strategy function to convert jiffies to seconds */
3082 int sysctl_jiffies(struct ctl_table *table,
3083                 void __user *oldval, size_t __user *oldlenp,
3084                 void __user *newval, size_t newlen)
3085 {
3086         if (oldval && oldlenp) {
3087                 size_t olen;
3088
3089                 if (get_user(olen, oldlenp))
3090                         return -EFAULT;
3091                 if (olen) {
3092                         int val;
3093
3094                         if (olen < sizeof(int))
3095                                 return -EINVAL;
3096
3097                         val = *(int *)(table->data) / HZ;
3098                         if (put_user(val, (int __user *)oldval))
3099                                 return -EFAULT;
3100                         if (put_user(sizeof(int), oldlenp))
3101                                 return -EFAULT;
3102                 }
3103         }
3104         if (newval && newlen) {
3105                 int new;
3106                 if (newlen != sizeof(int))
3107                         return -EINVAL;
3108                 if (get_user(new, (int __user *)newval))
3109                         return -EFAULT;
3110                 *(int *)(table->data) = new*HZ;
3111         }
3112         return 1;
3113 }
3114
3115 /* Strategy function to convert jiffies to seconds */
3116 int sysctl_ms_jiffies(struct ctl_table *table,
3117                 void __user *oldval, size_t __user *oldlenp,
3118                 void __user *newval, size_t newlen)
3119 {
3120         if (oldval && oldlenp) {
3121                 size_t olen;
3122
3123                 if (get_user(olen, oldlenp))
3124                         return -EFAULT;
3125                 if (olen) {
3126                         int val;
3127
3128                         if (olen < sizeof(int))
3129                                 return -EINVAL;
3130
3131                         val = jiffies_to_msecs(*(int *)(table->data));
3132                         if (put_user(val, (int __user *)oldval))
3133                                 return -EFAULT;
3134                         if (put_user(sizeof(int), oldlenp))
3135                                 return -EFAULT;
3136                 }
3137         }
3138         if (newval && newlen) {
3139                 int new;
3140                 if (newlen != sizeof(int))
3141                         return -EINVAL;
3142                 if (get_user(new, (int __user *)newval))
3143                         return -EFAULT;
3144                 *(int *)(table->data) = msecs_to_jiffies(new);
3145         }
3146         return 1;
3147 }
3148
3149
3150
3151 #else /* CONFIG_SYSCTL_SYSCALL */
3152
3153
3154 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3155 {
3156         struct __sysctl_args tmp;
3157         int error;
3158
3159         if (copy_from_user(&tmp, args, sizeof(tmp)))
3160                 return -EFAULT;
3161
3162         error = deprecated_sysctl_warning(&tmp);
3163
3164         /* If no error reading the parameters then just -ENOSYS ... */
3165         if (!error)
3166                 error = -ENOSYS;
3167
3168         return error;
3169 }
3170
3171 int sysctl_data(struct ctl_table *table,
3172                   void __user *oldval, size_t __user *oldlenp,
3173                   void __user *newval, size_t newlen)
3174 {
3175         return -ENOSYS;
3176 }
3177
3178 int sysctl_string(struct ctl_table *table,
3179                   void __user *oldval, size_t __user *oldlenp,
3180                   void __user *newval, size_t newlen)
3181 {
3182         return -ENOSYS;
3183 }
3184
3185 int sysctl_intvec(struct ctl_table *table,
3186                 void __user *oldval, size_t __user *oldlenp,
3187                 void __user *newval, size_t newlen)
3188 {
3189         return -ENOSYS;
3190 }
3191
3192 int sysctl_jiffies(struct ctl_table *table,
3193                 void __user *oldval, size_t __user *oldlenp,
3194                 void __user *newval, size_t newlen)
3195 {
3196         return -ENOSYS;
3197 }
3198
3199 int sysctl_ms_jiffies(struct ctl_table *table,
3200                 void __user *oldval, size_t __user *oldlenp,
3201                 void __user *newval, size_t newlen)
3202 {
3203         return -ENOSYS;
3204 }
3205
3206 #endif /* CONFIG_SYSCTL_SYSCALL */
3207
3208 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3209 {
3210         static int msg_count;
3211         int name[CTL_MAXNAME];
3212         int i;
3213
3214         /* Check args->nlen. */
3215         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3216                 return -ENOTDIR;
3217
3218         /* Read in the sysctl name for better debug message logging */
3219         for (i = 0; i < args->nlen; i++)
3220                 if (get_user(name[i], args->name + i))
3221                         return -EFAULT;
3222
3223         /* Ignore accesses to kernel.version */
3224         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3225                 return 0;
3226
3227         if (msg_count < 5) {
3228                 msg_count++;
3229                 printk(KERN_INFO
3230                         "warning: process `%s' used the deprecated sysctl "
3231                         "system call with ", current->comm);
3232                 for (i = 0; i < args->nlen; i++)
3233                         printk("%d.", name[i]);
3234                 printk("\n");
3235         }
3236         return 0;
3237 }
3238
3239 /*
3240  * No sense putting this after each symbol definition, twice,
3241  * exception granted :-)
3242  */
3243 EXPORT_SYMBOL(proc_dointvec);
3244 EXPORT_SYMBOL(proc_dointvec_jiffies);
3245 EXPORT_SYMBOL(proc_dointvec_minmax);
3246 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3247 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3248 EXPORT_SYMBOL(proc_dostring);
3249 EXPORT_SYMBOL(proc_doulongvec_minmax);
3250 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3251 EXPORT_SYMBOL(register_sysctl_table);
3252 EXPORT_SYMBOL(register_sysctl_paths);
3253 EXPORT_SYMBOL(sysctl_intvec);
3254 EXPORT_SYMBOL(sysctl_jiffies);
3255 EXPORT_SYMBOL(sysctl_ms_jiffies);
3256 EXPORT_SYMBOL(sysctl_string);
3257 EXPORT_SYMBOL(sysctl_data);
3258 EXPORT_SYMBOL(unregister_sysctl_table);