git.oblomov.eu Git - linux-2.6/blob - 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/utsname.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/hugetlb.h>
  40 #include <linux/initrd.h>
  41 #include <linux/key.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/vmstat.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50 #include <linux/ftrace.h>
  51 #include <linux/slow-work.h>
  52 #include <linux/perf_counter.h>
  53
  54 #include <asm/uaccess.h>
  55 #include <asm/processor.h>
  56
  57 #ifdef CONFIG_X86
  58 #include <asm/nmi.h>
  59 #include <asm/stacktrace.h>
  60 #include <asm/io.h>
  61 #endif
  62
  63 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  64
  65 #if defined(CONFIG_SYSCTL)
  66
  67 /* External variables not in a header file. */
  68 extern int C_A_D;
  69 extern int print_fatal_signals;
  70 extern int sysctl_overcommit_memory;
  71 extern int sysctl_overcommit_ratio;
  72 extern int sysctl_panic_on_oom;
  73 extern int sysctl_oom_kill_allocating_task;
  74 extern int sysctl_oom_dump_tasks;
  75 extern int max_threads;
  76 extern int core_uses_pid;
  77 extern int suid_dumpable;
  78 extern char core_pattern[];
  79 extern int pid_max;
  80 extern int min_free_kbytes;
  81 extern int pid_max_min, pid_max_max;
  82 extern int sysctl_drop_caches;
  83 extern int percpu_pagelist_fraction;
  84 extern int compat_log;
  85 extern int latencytop_enabled;
  86 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  87 #ifndef CONFIG_MMU
  88 extern int sysctl_nr_trim_pages;
  89 #endif
  90 #ifdef CONFIG_RCU_TORTURE_TEST
  91 extern int rcutorture_runnable;
  92 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  93
  94 /* Constants used for minimum and  maximum */
  95 #ifdef CONFIG_DETECT_SOFTLOCKUP
  96 static int sixty = 60;
  97 static int neg_one = -1;
  98 #endif
  99
 100 static int zero;
 101 static int __maybe_unused one = 1;
 102 static int __maybe_unused two = 2;
 103 static unsigned long one_ul = 1;
 104 static int one_hundred = 100;
 105
 106 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 107 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 108
 109 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 110 static int maxolduid = 65535;
 111 static int minolduid;
 112 static int min_percpu_pagelist_fract = 8;
 113
 114 static int ngroups_max = NGROUPS_MAX;
 115
 116 #ifdef CONFIG_MODULES
 117 extern char modprobe_path[];
 118 extern int modules_disabled;
 119 #endif
 120 #ifdef CONFIG_CHR_DEV_SG
 121 extern int sg_big_buff;
 122 #endif
 123
 124 #ifdef CONFIG_SPARC
 125 #include <asm/system.h>
 126 #endif
 127
 128 #ifdef CONFIG_SPARC64
 129 extern int sysctl_tsb_ratio;
 130 #endif
 131
 132 #ifdef __hppa__
 133 extern int pwrsw_enabled;
 134 extern int unaligned_enabled;
 135 #endif
 136
 137 #ifdef CONFIG_S390
 138 #ifdef CONFIG_MATHEMU
 139 extern int sysctl_ieee_emulation_warnings;
 140 #endif
 141 extern int sysctl_userprocess_debug;
 142 extern int spin_retry;
 143 #endif
 144
 145 #ifdef CONFIG_BSD_PROCESS_ACCT
 146 extern int acct_parm[];
 147 #endif
 148
 149 #ifdef CONFIG_IA64
 150 extern int no_unaligned_warning;
 151 extern int unaligned_dump_stack;
 152 #endif
 153
 154 #ifdef CONFIG_RT_MUTEXES
 155 extern int max_lock_depth;
 156 #endif
 157
 158 #ifdef CONFIG_PROC_SYSCTL
 159 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 160                   void __user *buffer, size_t *lenp, loff_t *ppos);
 161 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 162                                void __user *buffer, size_t *lenp, loff_t *ppos);
 163 #endif
 164
 165 static struct ctl_table root_table[];
 166 static struct ctl_table_root sysctl_table_root;
 167 static struct ctl_table_header root_table_header = {
 168         .count = 1,
 169         .ctl_table = root_table,
 170         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 171         .root = &sysctl_table_root,
 172         .set = &sysctl_table_root.default_set,
 173 };
 174 static struct ctl_table_root sysctl_table_root = {
 175         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 176         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 177 };
 178
 179 static struct ctl_table kern_table[];
 180 static struct ctl_table vm_table[];
 181 static struct ctl_table fs_table[];
 182 static struct ctl_table debug_table[];
 183 static struct ctl_table dev_table[];
 184 extern struct ctl_table random_table[];
 185 #ifdef CONFIG_INOTIFY_USER
 186 extern struct ctl_table inotify_table[];
 187 #endif
 188 #ifdef CONFIG_EPOLL
 189 extern struct ctl_table epoll_table[];
 190 #endif
 191
 192 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 193 int sysctl_legacy_va_layout;
 194 #endif
 195
 196 extern int prove_locking;
 197 extern int lock_stat;
 198
 199 /* The default sysctl tables: */
 200
 201 static struct ctl_table root_table[] = {
 202         {
 203                 .ctl_name       = CTL_KERN,
 204                 .procname       = "kernel",
 205                 .mode           = 0555,
 206                 .child          = kern_table,
 207         },
 208         {
 209                 .ctl_name       = CTL_VM,
 210                 .procname       = "vm",
 211                 .mode           = 0555,
 212                 .child          = vm_table,
 213         },
 214         {
 215                 .ctl_name       = CTL_FS,
 216                 .procname       = "fs",
 217                 .mode           = 0555,
 218                 .child          = fs_table,
 219         },
 220         {
 221                 .ctl_name       = CTL_DEBUG,
 222                 .procname       = "debug",
 223                 .mode           = 0555,
 224                 .child          = debug_table,
 225         },
 226         {
 227                 .ctl_name       = CTL_DEV,
 228                 .procname       = "dev",
 229                 .mode           = 0555,
 230                 .child          = dev_table,
 231         },
 232 /*
 233  * NOTE: do not add new entries to this table unless you have read
 234  * Documentation/sysctl/ctl_unnumbered.txt
 235  */
 236         { .ctl_name = 0 }
 237 };
 238
 239 #ifdef CONFIG_SCHED_DEBUG
 240 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 241 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 242 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 243 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 244 #endif
 245
 246 static struct ctl_table kern_table[] = {
 247 #ifdef CONFIG_SCHED_DEBUG
 248         {
 249                 .ctl_name       = CTL_UNNUMBERED,
 250                 .procname       = "sched_min_granularity_ns",
 251                 .data           = &sysctl_sched_min_granularity,
 252                 .maxlen         = sizeof(unsigned int),
 253                 .mode           = 0644,
 254                 .proc_handler   = &sched_nr_latency_handler,
 255                 .strategy       = &sysctl_intvec,
 256                 .extra1         = &min_sched_granularity_ns,
 257                 .extra2         = &max_sched_granularity_ns,
 258         },
 259         {
 260                 .ctl_name       = CTL_UNNUMBERED,
 261                 .procname       = "sched_latency_ns",
 262                 .data           = &sysctl_sched_latency,
 263                 .maxlen         = sizeof(unsigned int),
 264                 .mode           = 0644,
 265                 .proc_handler   = &sched_nr_latency_handler,
 266                 .strategy       = &sysctl_intvec,
 267                 .extra1         = &min_sched_granularity_ns,
 268                 .extra2         = &max_sched_granularity_ns,
 269         },
 270         {
 271                 .ctl_name       = CTL_UNNUMBERED,
 272                 .procname       = "sched_wakeup_granularity_ns",
 273                 .data           = &sysctl_sched_wakeup_granularity,
 274                 .maxlen         = sizeof(unsigned int),
 275                 .mode           = 0644,
 276                 .proc_handler   = &proc_dointvec_minmax,
 277                 .strategy       = &sysctl_intvec,
 278                 .extra1         = &min_wakeup_granularity_ns,
 279                 .extra2         = &max_wakeup_granularity_ns,
 280         },
 281         {
 282                 .ctl_name       = CTL_UNNUMBERED,
 283                 .procname       = "sched_shares_ratelimit",
 284                 .data           = &sysctl_sched_shares_ratelimit,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289         {
 290                 .ctl_name       = CTL_UNNUMBERED,
 291                 .procname       = "sched_shares_thresh",
 292                 .data           = &sysctl_sched_shares_thresh,
 293                 .maxlen         = sizeof(unsigned int),
 294                 .mode           = 0644,
 295                 .proc_handler   = &proc_dointvec_minmax,
 296                 .strategy       = &sysctl_intvec,
 297                 .extra1         = &zero,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_child_runs_first",
 302                 .data           = &sysctl_sched_child_runs_first,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec,
 306         },
 307         {
 308                 .ctl_name       = CTL_UNNUMBERED,
 309                 .procname       = "sched_features",
 310                 .data           = &sysctl_sched_features,
 311                 .maxlen         = sizeof(unsigned int),
 312                 .mode           = 0644,
 313                 .proc_handler   = &proc_dointvec,
 314         },
 315         {
 316                 .ctl_name       = CTL_UNNUMBERED,
 317                 .procname       = "sched_migration_cost",
 318                 .data           = &sysctl_sched_migration_cost,
 319                 .maxlen         = sizeof(unsigned int),
 320                 .mode           = 0644,
 321                 .proc_handler   = &proc_dointvec,
 322         },
 323         {
 324                 .ctl_name       = CTL_UNNUMBERED,
 325                 .procname       = "sched_nr_migrate",
 326                 .data           = &sysctl_sched_nr_migrate,
 327                 .maxlen         = sizeof(unsigned int),
 328                 .mode           = 0644,
 329                 .proc_handler   = &proc_dointvec,
 330         },
 331         {
 332                 .ctl_name       = CTL_UNNUMBERED,
 333                 .procname       = "timer_migration",
 334                 .data           = &sysctl_timer_migration,
 335                 .maxlen         = sizeof(unsigned int),
 336                 .mode           = 0644,
 337                 .proc_handler   = &proc_dointvec,
 338         },
 339 #endif
 340         {
 341                 .ctl_name       = CTL_UNNUMBERED,
 342                 .procname       = "sched_rt_period_us",
 343                 .data           = &sysctl_sched_rt_period,
 344                 .maxlen         = sizeof(unsigned int),
 345                 .mode           = 0644,
 346                 .proc_handler   = &sched_rt_handler,
 347         },
 348         {
 349                 .ctl_name       = CTL_UNNUMBERED,
 350                 .procname       = "sched_rt_runtime_us",
 351                 .data           = &sysctl_sched_rt_runtime,
 352                 .maxlen         = sizeof(int),
 353                 .mode           = 0644,
 354                 .proc_handler   = &sched_rt_handler,
 355         },
 356         {
 357                 .ctl_name       = CTL_UNNUMBERED,
 358                 .procname       = "sched_compat_yield",
 359                 .data           = &sysctl_sched_compat_yield,
 360                 .maxlen         = sizeof(unsigned int),
 361                 .mode           = 0644,
 362                 .proc_handler   = &proc_dointvec,
 363         },
 364 #ifdef CONFIG_PROVE_LOCKING
 365         {
 366                 .ctl_name       = CTL_UNNUMBERED,
 367                 .procname       = "prove_locking",
 368                 .data           = &prove_locking,
 369                 .maxlen         = sizeof(int),
 370                 .mode           = 0644,
 371                 .proc_handler   = &proc_dointvec,
 372         },
 373 #endif
 374 #ifdef CONFIG_LOCK_STAT
 375         {
 376                 .ctl_name       = CTL_UNNUMBERED,
 377                 .procname       = "lock_stat",
 378                 .data           = &lock_stat,
 379                 .maxlen         = sizeof(int),
 380                 .mode           = 0644,
 381                 .proc_handler   = &proc_dointvec,
 382         },
 383 #endif
 384         {
 385                 .ctl_name       = KERN_PANIC,
 386                 .procname       = "panic",
 387                 .data           = &panic_timeout,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = &proc_dointvec,
 391         },
 392         {
 393                 .ctl_name       = KERN_CORE_USES_PID,
 394                 .procname       = "core_uses_pid",
 395                 .data           = &core_uses_pid,
 396                 .maxlen         = sizeof(int),
 397                 .mode           = 0644,
 398                 .proc_handler   = &proc_dointvec,
 399         },
 400         {
 401                 .ctl_name       = KERN_CORE_PATTERN,
 402                 .procname       = "core_pattern",
 403                 .data           = core_pattern,
 404                 .maxlen         = CORENAME_MAX_SIZE,
 405                 .mode           = 0644,
 406                 .proc_handler   = &proc_dostring,
 407                 .strategy       = &sysctl_string,
 408         },
 409 #ifdef CONFIG_PROC_SYSCTL
 410         {
 411                 .procname       = "tainted",
 412                 .maxlen         = sizeof(long),
 413                 .mode           = 0644,
 414                 .proc_handler   = &proc_taint,
 415         },
 416 #endif
 417 #ifdef CONFIG_LATENCYTOP
 418         {
 419                 .procname       = "latencytop",
 420                 .data           = &latencytop_enabled,
 421                 .maxlen         = sizeof(int),
 422                 .mode           = 0644,
 423                 .proc_handler   = &proc_dointvec,
 424         },
 425 #endif
 426 #ifdef CONFIG_BLK_DEV_INITRD
 427         {
 428                 .ctl_name       = KERN_REALROOTDEV,
 429                 .procname       = "real-root-dev",
 430                 .data           = &real_root_dev,
 431                 .maxlen         = sizeof(int),
 432                 .mode           = 0644,
 433                 .proc_handler   = &proc_dointvec,
 434         },
 435 #endif
 436         {
 437                 .ctl_name       = CTL_UNNUMBERED,
 438                 .procname       = "print-fatal-signals",
 439                 .data           = &print_fatal_signals,
 440                 .maxlen         = sizeof(int),
 441                 .mode           = 0644,
 442                 .proc_handler   = &proc_dointvec,
 443         },
 444 #ifdef CONFIG_SPARC
 445         {
 446                 .ctl_name       = KERN_SPARC_REBOOT,
 447                 .procname       = "reboot-cmd",
 448                 .data           = reboot_command,
 449                 .maxlen         = 256,
 450                 .mode           = 0644,
 451                 .proc_handler   = &proc_dostring,
 452                 .strategy       = &sysctl_string,
 453         },
 454         {
 455                 .ctl_name       = KERN_SPARC_STOP_A,
 456                 .procname       = "stop-a",
 457                 .data           = &stop_a_enabled,
 458                 .maxlen         = sizeof (int),
 459                 .mode           = 0644,
 460                 .proc_handler   = &proc_dointvec,
 461         },
 462         {
 463                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 464                 .procname       = "scons-poweroff",
 465                 .data           = &scons_pwroff,
 466                 .maxlen         = sizeof (int),
 467                 .mode           = 0644,
 468                 .proc_handler   = &proc_dointvec,
 469         },
 470 #endif
 471 #ifdef CONFIG_SPARC64
 472         {
 473                 .ctl_name       = CTL_UNNUMBERED,
 474                 .procname       = "tsb-ratio",
 475                 .data           = &sysctl_tsb_ratio,
 476                 .maxlen         = sizeof (int),
 477                 .mode           = 0644,
 478                 .proc_handler   = &proc_dointvec,
 479         },
 480 #endif
 481 #ifdef __hppa__
 482         {
 483                 .ctl_name       = KERN_HPPA_PWRSW,
 484                 .procname       = "soft-power",
 485                 .data           = &pwrsw_enabled,
 486                 .maxlen         = sizeof (int),
 487                 .mode           = 0644,
 488                 .proc_handler   = &proc_dointvec,
 489         },
 490         {
 491                 .ctl_name       = KERN_HPPA_UNALIGNED,
 492                 .procname       = "unaligned-trap",
 493                 .data           = &unaligned_enabled,
 494                 .maxlen         = sizeof (int),
 495                 .mode           = 0644,
 496                 .proc_handler   = &proc_dointvec,
 497         },
 498 #endif
 499         {
 500                 .ctl_name       = KERN_CTLALTDEL,
 501                 .procname       = "ctrl-alt-del",
 502                 .data           = &C_A_D,
 503                 .maxlen         = sizeof(int),
 504                 .mode           = 0644,
 505                 .proc_handler   = &proc_dointvec,
 506         },
 507 #ifdef CONFIG_FUNCTION_TRACER
 508         {
 509                 .ctl_name       = CTL_UNNUMBERED,
 510                 .procname       = "ftrace_enabled",
 511                 .data           = &ftrace_enabled,
 512                 .maxlen         = sizeof(int),
 513                 .mode           = 0644,
 514                 .proc_handler   = &ftrace_enable_sysctl,
 515         },
 516 #endif
 517 #ifdef CONFIG_STACK_TRACER
 518         {
 519                 .ctl_name       = CTL_UNNUMBERED,
 520                 .procname       = "stack_tracer_enabled",
 521                 .data           = &stack_tracer_enabled,
 522                 .maxlen         = sizeof(int),
 523                 .mode           = 0644,
 524                 .proc_handler   = &stack_trace_sysctl,
 525         },
 526 #endif
 527 #ifdef CONFIG_TRACING
 528         {
 529                 .ctl_name       = CTL_UNNUMBERED,
 530                 .procname       = "ftrace_dump_on_oops",
 531                 .data           = &ftrace_dump_on_oops,
 532                 .maxlen         = sizeof(int),
 533                 .mode           = 0644,
 534                 .proc_handler   = &proc_dointvec,
 535         },
 536 #endif
 537 #ifdef CONFIG_MODULES
 538         {
 539                 .ctl_name       = KERN_MODPROBE,
 540                 .procname       = "modprobe",
 541                 .data           = &modprobe_path,
 542                 .maxlen         = KMOD_PATH_LEN,
 543                 .mode           = 0644,
 544                 .proc_handler   = &proc_dostring,
 545                 .strategy       = &sysctl_string,
 546         },
 547         {
 548                 .ctl_name       = CTL_UNNUMBERED,
 549                 .procname       = "modules_disabled",
 550                 .data           = &modules_disabled,
 551                 .maxlen         = sizeof(int),
 552                 .mode           = 0644,
 553                 /* only handle a transition from default "0" to "1" */
 554                 .proc_handler   = &proc_dointvec_minmax,
 555                 .extra1         = &one,
 556                 .extra2         = &one,
 557         },
 558 #endif
 559 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 560         {
 561                 .ctl_name       = KERN_HOTPLUG,
 562                 .procname       = "hotplug",
 563                 .data           = &uevent_helper,
 564                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 565                 .mode           = 0644,
 566                 .proc_handler   = &proc_dostring,
 567                 .strategy       = &sysctl_string,
 568         },
 569 #endif
 570 #ifdef CONFIG_CHR_DEV_SG
 571         {
 572                 .ctl_name       = KERN_SG_BIG_BUFF,
 573                 .procname       = "sg-big-buff",
 574                 .data           = &sg_big_buff,
 575                 .maxlen         = sizeof (int),
 576                 .mode           = 0444,
 577                 .proc_handler   = &proc_dointvec,
 578         },
 579 #endif
 580 #ifdef CONFIG_BSD_PROCESS_ACCT
 581         {
 582                 .ctl_name       = KERN_ACCT,
 583                 .procname       = "acct",
 584                 .data           = &acct_parm,
 585                 .maxlen         = 3*sizeof(int),
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dointvec,
 588         },
 589 #endif
 590 #ifdef CONFIG_MAGIC_SYSRQ
 591         {
 592                 .ctl_name       = KERN_SYSRQ,
 593                 .procname       = "sysrq",
 594                 .data           = &__sysrq_enabled,
 595                 .maxlen         = sizeof (int),
 596                 .mode           = 0644,
 597                 .proc_handler   = &proc_dointvec,
 598         },
 599 #endif
 600 #ifdef CONFIG_PROC_SYSCTL
 601         {
 602                 .procname       = "cad_pid",
 603                 .data           = NULL,
 604                 .maxlen         = sizeof (int),
 605                 .mode           = 0600,
 606                 .proc_handler   = &proc_do_cad_pid,
 607         },
 608 #endif
 609         {
 610                 .ctl_name       = KERN_MAX_THREADS,
 611                 .procname       = "threads-max",
 612                 .data           = &max_threads,
 613                 .maxlen         = sizeof(int),
 614                 .mode           = 0644,
 615                 .proc_handler   = &proc_dointvec,
 616         },
 617         {
 618                 .ctl_name       = KERN_RANDOM,
 619                 .procname       = "random",
 620                 .mode           = 0555,
 621                 .child          = random_table,
 622         },
 623         {
 624                 .ctl_name       = KERN_OVERFLOWUID,
 625                 .procname       = "overflowuid",
 626                 .data           = &overflowuid,
 627                 .maxlen         = sizeof(int),
 628                 .mode           = 0644,
 629                 .proc_handler   = &proc_dointvec_minmax,
 630                 .strategy       = &sysctl_intvec,
 631                 .extra1         = &minolduid,
 632                 .extra2         = &maxolduid,
 633         },
 634         {
 635                 .ctl_name       = KERN_OVERFLOWGID,
 636                 .procname       = "overflowgid",
 637                 .data           = &overflowgid,
 638                 .maxlen         = sizeof(int),
 639                 .mode           = 0644,
 640                 .proc_handler   = &proc_dointvec_minmax,
 641                 .strategy       = &sysctl_intvec,
 642                 .extra1         = &minolduid,
 643                 .extra2         = &maxolduid,
 644         },
 645 #ifdef CONFIG_S390
 646 #ifdef CONFIG_MATHEMU
 647         {
 648                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 649                 .procname       = "ieee_emulation_warnings",
 650                 .data           = &sysctl_ieee_emulation_warnings,
 651                 .maxlen         = sizeof(int),
 652                 .mode           = 0644,
 653                 .proc_handler   = &proc_dointvec,
 654         },
 655 #endif
 656         {
 657                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 658                 .procname       = "userprocess_debug",
 659                 .data           = &sysctl_userprocess_debug,
 660                 .maxlen         = sizeof(int),
 661                 .mode           = 0644,
 662                 .proc_handler   = &proc_dointvec,
 663         },
 664 #endif
 665         {
 666                 .ctl_name       = KERN_PIDMAX,
 667                 .procname       = "pid_max",
 668                 .data           = &pid_max,
 669                 .maxlen         = sizeof (int),
 670                 .mode           = 0644,
 671                 .proc_handler   = &proc_dointvec_minmax,
 672                 .strategy       = sysctl_intvec,
 673                 .extra1         = &pid_max_min,
 674                 .extra2         = &pid_max_max,
 675         },
 676         {
 677                 .ctl_name       = KERN_PANIC_ON_OOPS,
 678                 .procname       = "panic_on_oops",
 679                 .data           = &panic_on_oops,
 680                 .maxlen         = sizeof(int),
 681                 .mode           = 0644,
 682                 .proc_handler   = &proc_dointvec,
 683         },
 684 #if defined CONFIG_PRINTK
 685         {
 686                 .ctl_name       = KERN_PRINTK,
 687                 .procname       = "printk",
 688                 .data           = &console_loglevel,
 689                 .maxlen         = 4*sizeof(int),
 690                 .mode           = 0644,
 691                 .proc_handler   = &proc_dointvec,
 692         },
 693         {
 694                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 695                 .procname       = "printk_ratelimit",
 696                 .data           = &printk_ratelimit_state.interval,
 697                 .maxlen         = sizeof(int),
 698                 .mode           = 0644,
 699                 .proc_handler   = &proc_dointvec_jiffies,
 700                 .strategy       = &sysctl_jiffies,
 701         },
 702         {
 703                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 704                 .procname       = "printk_ratelimit_burst",
 705                 .data           = &printk_ratelimit_state.burst,
 706                 .maxlen         = sizeof(int),
 707                 .mode           = 0644,
 708                 .proc_handler   = &proc_dointvec,
 709         },
 710 #endif
 711         {
 712                 .ctl_name       = KERN_NGROUPS_MAX,
 713                 .procname       = "ngroups_max",
 714                 .data           = &ngroups_max,
 715                 .maxlen         = sizeof (int),
 716                 .mode           = 0444,
 717                 .proc_handler   = &proc_dointvec,
 718         },
 719 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 720         {
 721                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 722                 .procname       = "unknown_nmi_panic",
 723                 .data           = &unknown_nmi_panic,
 724                 .maxlen         = sizeof (int),
 725                 .mode           = 0644,
 726                 .proc_handler   = &proc_dointvec,
 727         },
 728         {
 729                 .procname       = "nmi_watchdog",
 730                 .data           = &nmi_watchdog_enabled,
 731                 .maxlen         = sizeof (int),
 732                 .mode           = 0644,
 733                 .proc_handler   = &proc_nmi_enabled,
 734         },
 735 #endif
 736 #if defined(CONFIG_X86)
 737         {
 738                 .ctl_name       = KERN_PANIC_ON_NMI,
 739                 .procname       = "panic_on_unrecovered_nmi",
 740                 .data           = &panic_on_unrecovered_nmi,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0644,
 743                 .proc_handler   = &proc_dointvec,
 744         },
 745         {
 746                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 747                 .procname       = "bootloader_type",
 748                 .data           = &bootloader_type,
 749                 .maxlen         = sizeof (int),
 750                 .mode           = 0444,
 751                 .proc_handler   = &proc_dointvec,
 752         },
 753         {
 754                 .ctl_name       = CTL_UNNUMBERED,
 755                 .procname       = "bootloader_version",
 756                 .data           = &bootloader_version,
 757                 .maxlen         = sizeof (int),
 758                 .mode           = 0444,
 759                 .proc_handler   = &proc_dointvec,
 760         },
 761         {
 762                 .ctl_name       = CTL_UNNUMBERED,
 763                 .procname       = "kstack_depth_to_print",
 764                 .data           = &kstack_depth_to_print,
 765                 .maxlen         = sizeof(int),
 766                 .mode           = 0644,
 767                 .proc_handler   = &proc_dointvec,
 768         },
 769         {
 770                 .ctl_name       = CTL_UNNUMBERED,
 771                 .procname       = "io_delay_type",
 772                 .data           = &io_delay_type,
 773                 .maxlen         = sizeof(int),
 774                 .mode           = 0644,
 775                 .proc_handler   = &proc_dointvec,
 776         },
 777 #endif
 778 #if defined(CONFIG_MMU)
 779         {
 780                 .ctl_name       = KERN_RANDOMIZE,
 781                 .procname       = "randomize_va_space",
 782                 .data           = &randomize_va_space,
 783                 .maxlen         = sizeof(int),
 784                 .mode           = 0644,
 785                 .proc_handler   = &proc_dointvec,
 786         },
 787 #endif
 788 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 789         {
 790                 .ctl_name       = KERN_SPIN_RETRY,
 791                 .procname       = "spin_retry",
 792                 .data           = &spin_retry,
 793                 .maxlen         = sizeof (int),
 794                 .mode           = 0644,
 795                 .proc_handler   = &proc_dointvec,
 796         },
 797 #endif
 798 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 799         {
 800                 .procname       = "acpi_video_flags",
 801                 .data           = &acpi_realmode_flags,
 802                 .maxlen         = sizeof (unsigned long),
 803                 .mode           = 0644,
 804                 .proc_handler   = &proc_doulongvec_minmax,
 805         },
 806 #endif
 807 #ifdef CONFIG_IA64
 808         {
 809                 .ctl_name       = KERN_IA64_UNALIGNED,
 810                 .procname       = "ignore-unaligned-usertrap",
 811                 .data           = &no_unaligned_warning,
 812                 .maxlen         = sizeof (int),
 813                 .mode           = 0644,
 814                 .proc_handler   = &proc_dointvec,
 815         },
 816         {
 817                 .ctl_name       = CTL_UNNUMBERED,
 818                 .procname       = "unaligned-dump-stack",
 819                 .data           = &unaligned_dump_stack,
 820                 .maxlen         = sizeof (int),
 821                 .mode           = 0644,
 822                 .proc_handler   = &proc_dointvec,
 823         },
 824 #endif
 825 #ifdef CONFIG_DETECT_SOFTLOCKUP
 826         {
 827                 .ctl_name       = CTL_UNNUMBERED,
 828                 .procname       = "softlockup_panic",
 829                 .data           = &softlockup_panic,
 830                 .maxlen         = sizeof(int),
 831                 .mode           = 0644,
 832                 .proc_handler   = &proc_dointvec_minmax,
 833                 .strategy       = &sysctl_intvec,
 834                 .extra1         = &zero,
 835                 .extra2         = &one,
 836         },
 837         {
 838                 .ctl_name       = CTL_UNNUMBERED,
 839                 .procname       = "softlockup_thresh",
 840                 .data           = &softlockup_thresh,
 841                 .maxlen         = sizeof(int),
 842                 .mode           = 0644,
 843                 .proc_handler   = &proc_dosoftlockup_thresh,
 844                 .strategy       = &sysctl_intvec,
 845                 .extra1         = &neg_one,
 846                 .extra2         = &sixty,
 847         },
 848 #endif
 849 #ifdef CONFIG_DETECT_HUNG_TASK
 850         {
 851                 .ctl_name       = CTL_UNNUMBERED,
 852                 .procname       = "hung_task_panic",
 853                 .data           = &sysctl_hung_task_panic,
 854                 .maxlen         = sizeof(int),
 855                 .mode           = 0644,
 856                 .proc_handler   = &proc_dointvec_minmax,
 857                 .strategy       = &sysctl_intvec,
 858                 .extra1         = &zero,
 859                 .extra2         = &one,
 860         },
 861         {
 862                 .ctl_name       = CTL_UNNUMBERED,
 863                 .procname       = "hung_task_check_count",
 864                 .data           = &sysctl_hung_task_check_count,
 865                 .maxlen         = sizeof(unsigned long),
 866                 .mode           = 0644,
 867                 .proc_handler   = &proc_doulongvec_minmax,
 868                 .strategy       = &sysctl_intvec,
 869         },
 870         {
 871                 .ctl_name       = CTL_UNNUMBERED,
 872                 .procname       = "hung_task_timeout_secs",
 873                 .data           = &sysctl_hung_task_timeout_secs,
 874                 .maxlen         = sizeof(unsigned long),
 875                 .mode           = 0644,
 876                 .proc_handler   = &proc_dohung_task_timeout_secs,
 877                 .strategy       = &sysctl_intvec,
 878         },
 879         {
 880                 .ctl_name       = CTL_UNNUMBERED,
 881                 .procname       = "hung_task_warnings",
 882                 .data           = &sysctl_hung_task_warnings,
 883                 .maxlen         = sizeof(unsigned long),
 884                 .mode           = 0644,
 885                 .proc_handler   = &proc_doulongvec_minmax,
 886                 .strategy       = &sysctl_intvec,
 887         },
 888 #endif
 889 #ifdef CONFIG_COMPAT
 890         {
 891                 .ctl_name       = KERN_COMPAT_LOG,
 892                 .procname       = "compat-log",
 893                 .data           = &compat_log,
 894                 .maxlen         = sizeof (int),
 895                 .mode           = 0644,
 896                 .proc_handler   = &proc_dointvec,
 897         },
 898 #endif
 899 #ifdef CONFIG_RT_MUTEXES
 900         {
 901                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 902                 .procname       = "max_lock_depth",
 903                 .data           = &max_lock_depth,
 904                 .maxlen         = sizeof(int),
 905                 .mode           = 0644,
 906                 .proc_handler   = &proc_dointvec,
 907         },
 908 #endif
 909         {
 910                 .ctl_name       = CTL_UNNUMBERED,
 911                 .procname       = "poweroff_cmd",
 912                 .data           = &poweroff_cmd,
 913                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 914                 .mode           = 0644,
 915                 .proc_handler   = &proc_dostring,
 916                 .strategy       = &sysctl_string,
 917         },
 918 #ifdef CONFIG_KEYS
 919         {
 920                 .ctl_name       = CTL_UNNUMBERED,
 921                 .procname       = "keys",
 922                 .mode           = 0555,
 923                 .child          = key_sysctls,
 924         },
 925 #endif
 926 #ifdef CONFIG_RCU_TORTURE_TEST
 927         {
 928                 .ctl_name       = CTL_UNNUMBERED,
 929                 .procname       = "rcutorture_runnable",
 930                 .data           = &rcutorture_runnable,
 931                 .maxlen         = sizeof(int),
 932                 .mode           = 0644,
 933                 .proc_handler   = &proc_dointvec,
 934         },
 935 #endif
 936 #ifdef CONFIG_SLOW_WORK
 937         {
 938                 .ctl_name       = CTL_UNNUMBERED,
 939                 .procname       = "slow-work",
 940                 .mode           = 0555,
 941                 .child          = slow_work_sysctls,
 942         },
 943 #endif
 944 #ifdef CONFIG_PERF_COUNTERS
 945         {
 946                 .ctl_name       = CTL_UNNUMBERED,
 947                 .procname       = "perf_counter_paranoid",
 948                 .data           = &sysctl_perf_counter_paranoid,
 949                 .maxlen         = sizeof(sysctl_perf_counter_paranoid),
 950                 .mode           = 0644,
 951                 .proc_handler   = &proc_dointvec,
 952         },
 953         {
 954                 .ctl_name       = CTL_UNNUMBERED,
 955                 .procname       = "perf_counter_mlock_kb",
 956                 .data           = &sysctl_perf_counter_mlock,
 957                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
 958                 .mode           = 0644,
 959                 .proc_handler   = &proc_dointvec,
 960         },
 961         {
 962                 .ctl_name       = CTL_UNNUMBERED,
 963                 .procname       = "perf_counter_max_sample_rate",
 964                 .data           = &sysctl_perf_counter_sample_rate,
 965                 .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
 966                 .mode           = 0644,
 967                 .proc_handler   = &proc_dointvec,
 968         },
 969 #endif
 970 /*
 971  * NOTE: do not add new entries to this table unless you have read
 972  * Documentation/sysctl/ctl_unnumbered.txt
 973  */
 974         { .ctl_name = 0 }
 975 };
 976
 977 static struct ctl_table vm_table[] = {
 978         {
 979                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 980                 .procname       = "overcommit_memory",
 981                 .data           = &sysctl_overcommit_memory,
 982                 .maxlen         = sizeof(sysctl_overcommit_memory),
 983                 .mode           = 0644,
 984                 .proc_handler   = &proc_dointvec,
 985         },
 986         {
 987                 .ctl_name       = VM_PANIC_ON_OOM,
 988                 .procname       = "panic_on_oom",
 989                 .data           = &sysctl_panic_on_oom,
 990                 .maxlen         = sizeof(sysctl_panic_on_oom),
 991                 .mode           = 0644,
 992                 .proc_handler   = &proc_dointvec,
 993         },
 994         {
 995                 .ctl_name       = CTL_UNNUMBERED,
 996                 .procname       = "oom_kill_allocating_task",
 997                 .data           = &sysctl_oom_kill_allocating_task,
 998                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 999                 .mode           = 0644,
1000                 .proc_handler   = &proc_dointvec,
1001         },
1002         {
1003                 .ctl_name       = CTL_UNNUMBERED,
1004                 .procname       = "oom_dump_tasks",
1005                 .data           = &sysctl_oom_dump_tasks,
1006                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1007                 .mode           = 0644,
1008                 .proc_handler   = &proc_dointvec,
1009         },
1010         {
1011                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1012                 .procname       = "overcommit_ratio",
1013                 .data           = &sysctl_overcommit_ratio,
1014                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1015                 .mode           = 0644,
1016                 .proc_handler   = &proc_dointvec,
1017         },
1018         {
1019                 .ctl_name       = VM_PAGE_CLUSTER,
1020                 .procname       = "page-cluster",
1021                 .data           = &page_cluster,
1022                 .maxlen         = sizeof(int),
1023                 .mode           = 0644,
1024                 .proc_handler   = &proc_dointvec,
1025         },
1026         {
1027                 .ctl_name       = VM_DIRTY_BACKGROUND,
1028                 .procname       = "dirty_background_ratio",
1029                 .data           = &dirty_background_ratio,
1030                 .maxlen         = sizeof(dirty_background_ratio),
1031                 .mode           = 0644,
1032                 .proc_handler   = &dirty_background_ratio_handler,
1033                 .strategy       = &sysctl_intvec,
1034                 .extra1         = &zero,
1035                 .extra2         = &one_hundred,
1036         },
1037         {
1038                 .ctl_name       = CTL_UNNUMBERED,
1039                 .procname       = "dirty_background_bytes",
1040                 .data           = &dirty_background_bytes,
1041                 .maxlen         = sizeof(dirty_background_bytes),
1042                 .mode           = 0644,
1043                 .proc_handler   = &dirty_background_bytes_handler,
1044                 .strategy       = &sysctl_intvec,
1045                 .extra1         = &one_ul,
1046         },
1047         {
1048                 .ctl_name       = VM_DIRTY_RATIO,
1049                 .procname       = "dirty_ratio",
1050                 .data           = &vm_dirty_ratio,
1051                 .maxlen         = sizeof(vm_dirty_ratio),
1052                 .mode           = 0644,
1053                 .proc_handler   = &dirty_ratio_handler,
1054                 .strategy       = &sysctl_intvec,
1055                 .extra1         = &zero,
1056                 .extra2         = &one_hundred,
1057         },
1058         {
1059                 .ctl_name       = CTL_UNNUMBERED,
1060                 .procname       = "dirty_bytes",
1061                 .data           = &vm_dirty_bytes,
1062                 .maxlen         = sizeof(vm_dirty_bytes),
1063                 .mode           = 0644,
1064                 .proc_handler   = &dirty_bytes_handler,
1065                 .strategy       = &sysctl_intvec,
1066                 .extra1         = &dirty_bytes_min,
1067         },
1068         {
1069                 .procname       = "dirty_writeback_centisecs",
1070                 .data           = &dirty_writeback_interval,
1071                 .maxlen         = sizeof(dirty_writeback_interval),
1072                 .mode           = 0644,
1073                 .proc_handler   = &dirty_writeback_centisecs_handler,
1074         },
1075         {
1076                 .procname       = "dirty_expire_centisecs",
1077                 .data           = &dirty_expire_interval,
1078                 .maxlen         = sizeof(dirty_expire_interval),
1079                 .mode           = 0644,
1080                 .proc_handler   = &proc_dointvec,
1081         },
1082         {
1083                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1084                 .procname       = "nr_pdflush_threads",
1085                 .data           = &nr_pdflush_threads,
1086                 .maxlen         = sizeof nr_pdflush_threads,
1087                 .mode           = 0444 /* read-only*/,
1088                 .proc_handler   = &proc_dointvec,
1089         },
1090         {
1091                 .ctl_name       = VM_SWAPPINESS,
1092                 .procname       = "swappiness",
1093                 .data           = &vm_swappiness,
1094                 .maxlen         = sizeof(vm_swappiness),
1095                 .mode           = 0644,
1096                 .proc_handler   = &proc_dointvec_minmax,
1097                 .strategy       = &sysctl_intvec,
1098                 .extra1         = &zero,
1099                 .extra2         = &one_hundred,
1100         },
1101 #ifdef CONFIG_HUGETLB_PAGE
1102          {
1103                 .procname       = "nr_hugepages",
1104                 .data           = NULL,
1105                 .maxlen         = sizeof(unsigned long),
1106                 .mode           = 0644,
1107                 .proc_handler   = &hugetlb_sysctl_handler,
1108                 .extra1         = (void *)&hugetlb_zero,
1109                 .extra2         = (void *)&hugetlb_infinity,
1110          },
1111          {
1112                 .ctl_name       = VM_HUGETLB_GROUP,
1113                 .procname       = "hugetlb_shm_group",
1114                 .data           = &sysctl_hugetlb_shm_group,
1115                 .maxlen         = sizeof(gid_t),
1116                 .mode           = 0644,
1117                 .proc_handler   = &proc_dointvec,
1118          },
1119          {
1120                 .ctl_name       = CTL_UNNUMBERED,
1121                 .procname       = "hugepages_treat_as_movable",
1122                 .data           = &hugepages_treat_as_movable,
1123                 .maxlen         = sizeof(int),
1124                 .mode           = 0644,
1125                 .proc_handler   = &hugetlb_treat_movable_handler,
1126         },
1127         {
1128                 .ctl_name       = CTL_UNNUMBERED,
1129                 .procname       = "nr_overcommit_hugepages",
1130                 .data           = NULL,
1131                 .maxlen         = sizeof(unsigned long),
1132                 .mode           = 0644,
1133                 .proc_handler   = &hugetlb_overcommit_handler,
1134                 .extra1         = (void *)&hugetlb_zero,
1135                 .extra2         = (void *)&hugetlb_infinity,
1136         },
1137 #endif
1138         {
1139                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1140                 .procname       = "lowmem_reserve_ratio",
1141                 .data           = &sysctl_lowmem_reserve_ratio,
1142                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1143                 .mode           = 0644,
1144                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1145                 .strategy       = &sysctl_intvec,
1146         },
1147         {
1148                 .ctl_name       = VM_DROP_PAGECACHE,
1149                 .procname       = "drop_caches",
1150                 .data           = &sysctl_drop_caches,
1151                 .maxlen         = sizeof(int),
1152                 .mode           = 0644,
1153                 .proc_handler   = drop_caches_sysctl_handler,
1154                 .strategy       = &sysctl_intvec,
1155         },
1156         {
1157                 .ctl_name       = VM_MIN_FREE_KBYTES,
1158                 .procname       = "min_free_kbytes",
1159                 .data           = &min_free_kbytes,
1160                 .maxlen         = sizeof(min_free_kbytes),
1161                 .mode           = 0644,
1162                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1163                 .strategy       = &sysctl_intvec,
1164                 .extra1         = &zero,
1165         },
1166         {
1167                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1168                 .procname       = "percpu_pagelist_fraction",
1169                 .data           = &percpu_pagelist_fraction,
1170                 .maxlen         = sizeof(percpu_pagelist_fraction),
1171                 .mode           = 0644,
1172                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1173                 .strategy       = &sysctl_intvec,
1174                 .extra1         = &min_percpu_pagelist_fract,
1175         },
1176 #ifdef CONFIG_MMU
1177         {
1178                 .ctl_name       = VM_MAX_MAP_COUNT,
1179                 .procname       = "max_map_count",
1180                 .data           = &sysctl_max_map_count,
1181                 .maxlen         = sizeof(sysctl_max_map_count),
1182                 .mode           = 0644,
1183                 .proc_handler   = &proc_dointvec
1184         },
1185 #else
1186         {
1187                 .ctl_name       = CTL_UNNUMBERED,
1188                 .procname       = "nr_trim_pages",
1189                 .data           = &sysctl_nr_trim_pages,
1190                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1191                 .mode           = 0644,
1192                 .proc_handler   = &proc_dointvec_minmax,
1193                 .strategy       = &sysctl_intvec,
1194                 .extra1         = &zero,
1195         },
1196 #endif
1197         {
1198                 .ctl_name       = VM_LAPTOP_MODE,
1199                 .procname       = "laptop_mode",
1200                 .data           = &laptop_mode,
1201                 .maxlen         = sizeof(laptop_mode),
1202                 .mode           = 0644,
1203                 .proc_handler   = &proc_dointvec_jiffies,
1204                 .strategy       = &sysctl_jiffies,
1205         },
1206         {
1207                 .ctl_name       = VM_BLOCK_DUMP,
1208                 .procname       = "block_dump",
1209                 .data           = &block_dump,
1210                 .maxlen         = sizeof(block_dump),
1211                 .mode           = 0644,
1212                 .proc_handler   = &proc_dointvec,
1213                 .strategy       = &sysctl_intvec,
1214                 .extra1         = &zero,
1215         },
1216         {
1217                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1218                 .procname       = "vfs_cache_pressure",
1219                 .data           = &sysctl_vfs_cache_pressure,
1220                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1221                 .mode           = 0644,
1222                 .proc_handler   = &proc_dointvec,
1223                 .strategy       = &sysctl_intvec,
1224                 .extra1         = &zero,
1225         },
1226 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1227         {
1228                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1229                 .procname       = "legacy_va_layout",
1230                 .data           = &sysctl_legacy_va_layout,
1231                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1232                 .mode           = 0644,
1233                 .proc_handler   = &proc_dointvec,
1234                 .strategy       = &sysctl_intvec,
1235                 .extra1         = &zero,
1236         },
1237 #endif
1238 #ifdef CONFIG_NUMA
1239         {
1240                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1241                 .procname       = "zone_reclaim_mode",
1242                 .data           = &zone_reclaim_mode,
1243                 .maxlen         = sizeof(zone_reclaim_mode),
1244                 .mode           = 0644,
1245                 .proc_handler   = &proc_dointvec,
1246                 .strategy       = &sysctl_intvec,
1247                 .extra1         = &zero,
1248         },
1249         {
1250                 .ctl_name       = VM_MIN_UNMAPPED,
1251                 .procname       = "min_unmapped_ratio",
1252                 .data           = &sysctl_min_unmapped_ratio,
1253                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1254                 .mode           = 0644,
1255                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1256                 .strategy       = &sysctl_intvec,
1257                 .extra1         = &zero,
1258                 .extra2         = &one_hundred,
1259         },
1260         {
1261                 .ctl_name       = VM_MIN_SLAB,
1262                 .procname       = "min_slab_ratio",
1263                 .data           = &sysctl_min_slab_ratio,
1264                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1265                 .mode           = 0644,
1266                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1267                 .strategy       = &sysctl_intvec,
1268                 .extra1         = &zero,
1269                 .extra2         = &one_hundred,
1270         },
1271 #endif
1272 #ifdef CONFIG_SMP
1273         {
1274                 .ctl_name       = CTL_UNNUMBERED,
1275                 .procname       = "stat_interval",
1276                 .data           = &sysctl_stat_interval,
1277                 .maxlen         = sizeof(sysctl_stat_interval),
1278                 .mode           = 0644,
1279                 .proc_handler   = &proc_dointvec_jiffies,
1280                 .strategy       = &sysctl_jiffies,
1281         },
1282 #endif
1283         {
1284                 .ctl_name       = CTL_UNNUMBERED,
1285                 .procname       = "mmap_min_addr",
1286                 .data           = &mmap_min_addr,
1287                 .maxlen         = sizeof(unsigned long),
1288                 .mode           = 0644,
1289                 .proc_handler   = &proc_doulongvec_minmax,
1290         },
1291 #ifdef CONFIG_NUMA
1292         {
1293                 .ctl_name       = CTL_UNNUMBERED,
1294                 .procname       = "numa_zonelist_order",
1295                 .data           = &numa_zonelist_order,
1296                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1297                 .mode           = 0644,
1298                 .proc_handler   = &numa_zonelist_order_handler,
1299                 .strategy       = &sysctl_string,
1300         },
1301 #endif
1302 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1303    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1304         {
1305                 .ctl_name       = VM_VDSO_ENABLED,
1306                 .procname       = "vdso_enabled",
1307                 .data           = &vdso_enabled,
1308                 .maxlen         = sizeof(vdso_enabled),
1309                 .mode           = 0644,
1310                 .proc_handler   = &proc_dointvec,
1311                 .strategy       = &sysctl_intvec,
1312                 .extra1         = &zero,
1313         },
1314 #endif
1315 #ifdef CONFIG_HIGHMEM
1316         {
1317                 .ctl_name       = CTL_UNNUMBERED,
1318                 .procname       = "highmem_is_dirtyable",
1319                 .data           = &vm_highmem_is_dirtyable,
1320                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1321                 .mode           = 0644,
1322                 .proc_handler   = &proc_dointvec_minmax,
1323                 .strategy       = &sysctl_intvec,
1324                 .extra1         = &zero,
1325                 .extra2         = &one,
1326         },
1327 #endif
1328 #ifdef CONFIG_UNEVICTABLE_LRU
1329         {
1330                 .ctl_name       = CTL_UNNUMBERED,
1331                 .procname       = "scan_unevictable_pages",
1332                 .data           = &scan_unevictable_pages,
1333                 .maxlen         = sizeof(scan_unevictable_pages),
1334                 .mode           = 0644,
1335                 .proc_handler   = &scan_unevictable_handler,
1336         },
1337 #endif
1338 /*
1339  * NOTE: do not add new entries to this table unless you have read
1340  * Documentation/sysctl/ctl_unnumbered.txt
1341  */
1342         { .ctl_name = 0 }
1343 };
1344
1345 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1346 static struct ctl_table binfmt_misc_table[] = {
1347         { .ctl_name = 0 }
1348 };
1349 #endif
1350
1351 static struct ctl_table fs_table[] = {
1352         {
1353                 .ctl_name       = FS_NRINODE,
1354                 .procname       = "inode-nr",
1355                 .data           = &inodes_stat,
1356                 .maxlen         = 2*sizeof(int),
1357                 .mode           = 0444,
1358                 .proc_handler   = &proc_dointvec,
1359         },
1360         {
1361                 .ctl_name       = FS_STATINODE,
1362                 .procname       = "inode-state",
1363                 .data           = &inodes_stat,
1364                 .maxlen         = 7*sizeof(int),
1365                 .mode           = 0444,
1366                 .proc_handler   = &proc_dointvec,
1367         },
1368         {
1369                 .procname       = "file-nr",
1370                 .data           = &files_stat,
1371                 .maxlen         = 3*sizeof(int),
1372                 .mode           = 0444,
1373                 .proc_handler   = &proc_nr_files,
1374         },
1375         {
1376                 .ctl_name       = FS_MAXFILE,
1377                 .procname       = "file-max",
1378                 .data           = &files_stat.max_files,
1379                 .maxlen         = sizeof(int),
1380                 .mode           = 0644,
1381                 .proc_handler   = &proc_dointvec,
1382         },
1383         {
1384                 .ctl_name       = CTL_UNNUMBERED,
1385                 .procname       = "nr_open",
1386                 .data           = &sysctl_nr_open,
1387                 .maxlen         = sizeof(int),
1388                 .mode           = 0644,
1389                 .proc_handler   = &proc_dointvec_minmax,
1390                 .extra1         = &sysctl_nr_open_min,
1391                 .extra2         = &sysctl_nr_open_max,
1392         },
1393         {
1394                 .ctl_name       = FS_DENTRY,
1395                 .procname       = "dentry-state",
1396                 .data           = &dentry_stat,
1397                 .maxlen         = 6*sizeof(int),
1398                 .mode           = 0444,
1399                 .proc_handler   = &proc_dointvec,
1400         },
1401         {
1402                 .ctl_name       = FS_OVERFLOWUID,
1403                 .procname       = "overflowuid",
1404                 .data           = &fs_overflowuid,
1405                 .maxlen         = sizeof(int),
1406                 .mode           = 0644,
1407                 .proc_handler   = &proc_dointvec_minmax,
1408                 .strategy       = &sysctl_intvec,
1409                 .extra1         = &minolduid,
1410                 .extra2         = &maxolduid,
1411         },
1412         {
1413                 .ctl_name       = FS_OVERFLOWGID,
1414                 .procname       = "overflowgid",
1415                 .data           = &fs_overflowgid,
1416                 .maxlen         = sizeof(int),
1417                 .mode           = 0644,
1418                 .proc_handler   = &proc_dointvec_minmax,
1419                 .strategy       = &sysctl_intvec,
1420                 .extra1         = &minolduid,
1421                 .extra2         = &maxolduid,
1422         },
1423 #ifdef CONFIG_FILE_LOCKING
1424         {
1425                 .ctl_name       = FS_LEASES,
1426                 .procname       = "leases-enable",
1427                 .data           = &leases_enable,
1428                 .maxlen         = sizeof(int),
1429                 .mode           = 0644,
1430                 .proc_handler   = &proc_dointvec,
1431         },
1432 #endif
1433 #ifdef CONFIG_DNOTIFY
1434         {
1435                 .ctl_name       = FS_DIR_NOTIFY,
1436                 .procname       = "dir-notify-enable",
1437                 .data           = &dir_notify_enable,
1438                 .maxlen         = sizeof(int),
1439                 .mode           = 0644,
1440                 .proc_handler   = &proc_dointvec,
1441         },
1442 #endif
1443 #ifdef CONFIG_MMU
1444 #ifdef CONFIG_FILE_LOCKING
1445         {
1446                 .ctl_name       = FS_LEASE_TIME,
1447                 .procname       = "lease-break-time",
1448                 .data           = &lease_break_time,
1449                 .maxlen         = sizeof(int),
1450                 .mode           = 0644,
1451                 .proc_handler   = &proc_dointvec,
1452         },
1453 #endif
1454 #ifdef CONFIG_AIO
1455         {
1456                 .procname       = "aio-nr",
1457                 .data           = &aio_nr,
1458                 .maxlen         = sizeof(aio_nr),
1459                 .mode           = 0444,
1460                 .proc_handler   = &proc_doulongvec_minmax,
1461         },
1462         {
1463                 .procname       = "aio-max-nr",
1464                 .data           = &aio_max_nr,
1465                 .maxlen         = sizeof(aio_max_nr),
1466                 .mode           = 0644,
1467                 .proc_handler   = &proc_doulongvec_minmax,
1468         },
1469 #endif /* CONFIG_AIO */
1470 #ifdef CONFIG_INOTIFY_USER
1471         {
1472                 .ctl_name       = FS_INOTIFY,
1473                 .procname       = "inotify",
1474                 .mode           = 0555,
1475                 .child          = inotify_table,
1476         },
1477 #endif
1478 #ifdef CONFIG_EPOLL
1479         {
1480                 .procname       = "epoll",
1481                 .mode           = 0555,
1482                 .child          = epoll_table,
1483         },
1484 #endif
1485 #endif
1486         {
1487                 .ctl_name       = KERN_SETUID_DUMPABLE,
1488                 .procname       = "suid_dumpable",
1489                 .data           = &suid_dumpable,
1490                 .maxlen         = sizeof(int),
1491                 .mode           = 0644,
1492                 .proc_handler   = &proc_dointvec_minmax,
1493                 .strategy       = &sysctl_intvec,
1494                 .extra1         = &zero,
1495                 .extra2         = &two,
1496         },
1497 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1498         {
1499                 .ctl_name       = CTL_UNNUMBERED,
1500                 .procname       = "binfmt_misc",
1501                 .mode           = 0555,
1502                 .child          = binfmt_misc_table,
1503         },
1504 #endif
1505 /*
1506  * NOTE: do not add new entries to this table unless you have read
1507  * Documentation/sysctl/ctl_unnumbered.txt
1508  */
1509         { .ctl_name = 0 }
1510 };
1511
1512 static struct ctl_table debug_table[] = {
1513 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1514         {
1515                 .ctl_name       = CTL_UNNUMBERED,
1516                 .procname       = "exception-trace",
1517                 .data           = &show_unhandled_signals,
1518                 .maxlen         = sizeof(int),
1519                 .mode           = 0644,
1520                 .proc_handler   = proc_dointvec
1521         },
1522 #endif
1523         { .ctl_name = 0 }
1524 };
1525
1526 static struct ctl_table dev_table[] = {
1527         { .ctl_name = 0 }
1528 };
1529
1530 static DEFINE_SPINLOCK(sysctl_lock);
1531
1532 /* called under sysctl_lock */
1533 static int use_table(struct ctl_table_header *p)
1534 {
1535         if (unlikely(p->unregistering))
1536                 return 0;
1537         p->used++;
1538         return 1;
1539 }
1540
1541 /* called under sysctl_lock */
1542 static void unuse_table(struct ctl_table_header *p)
1543 {
1544         if (!--p->used)
1545                 if (unlikely(p->unregistering))
1546                         complete(p->unregistering);
1547 }
1548
1549 /* called under sysctl_lock, will reacquire if has to wait */
1550 static void start_unregistering(struct ctl_table_header *p)
1551 {
1552         /*
1553          * if p->used is 0, nobody will ever touch that entry again;
1554          * we'll eliminate all paths to it before dropping sysctl_lock
1555          */
1556         if (unlikely(p->used)) {
1557                 struct completion wait;
1558                 init_completion(&wait);
1559                 p->unregistering = &wait;
1560                 spin_unlock(&sysctl_lock);
1561                 wait_for_completion(&wait);
1562                 spin_lock(&sysctl_lock);
1563         } else {
1564                 /* anything non-NULL; we'll never dereference it */
1565                 p->unregistering = ERR_PTR(-EINVAL);
1566         }
1567         /*
1568          * do not remove from the list until nobody holds it; walking the
1569          * list in do_sysctl() relies on that.
1570          */
1571         list_del_init(&p->ctl_entry);
1572 }
1573
1574 void sysctl_head_get(struct ctl_table_header *head)
1575 {
1576         spin_lock(&sysctl_lock);
1577         head->count++;
1578         spin_unlock(&sysctl_lock);
1579 }
1580
1581 void sysctl_head_put(struct ctl_table_header *head)
1582 {
1583         spin_lock(&sysctl_lock);
1584         if (!--head->count)
1585                 kfree(head);
1586         spin_unlock(&sysctl_lock);
1587 }
1588
1589 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1590 {
1591         if (!head)
1592                 BUG();
1593         spin_lock(&sysctl_lock);
1594         if (!use_table(head))
1595                 head = ERR_PTR(-ENOENT);
1596         spin_unlock(&sysctl_lock);
1597         return head;
1598 }
1599
1600 void sysctl_head_finish(struct ctl_table_header *head)
1601 {
1602         if (!head)
1603                 return;
1604         spin_lock(&sysctl_lock);
1605         unuse_table(head);
1606         spin_unlock(&sysctl_lock);
1607 }
1608
1609 static struct ctl_table_set *
1610 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1611 {
1612         struct ctl_table_set *set = &root->default_set;
1613         if (root->lookup)
1614                 set = root->lookup(root, namespaces);
1615         return set;
1616 }
1617
1618 static struct list_head *
1619 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1620 {
1621         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1622         return &set->list;
1623 }
1624
1625 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1626                                             struct ctl_table_header *prev)
1627 {
1628         struct ctl_table_root *root;
1629         struct list_head *header_list;
1630         struct ctl_table_header *head;
1631         struct list_head *tmp;
1632
1633         spin_lock(&sysctl_lock);
1634         if (prev) {
1635                 head = prev;
1636                 tmp = &prev->ctl_entry;
1637                 unuse_table(prev);
1638                 goto next;
1639         }
1640         tmp = &root_table_header.ctl_entry;
1641         for (;;) {
1642                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1643
1644                 if (!use_table(head))
1645                         goto next;
1646                 spin_unlock(&sysctl_lock);
1647                 return head;
1648         next:
1649                 root = head->root;
1650                 tmp = tmp->next;
1651                 header_list = lookup_header_list(root, namespaces);
1652                 if (tmp != header_list)
1653                         continue;
1654
1655                 do {
1656                         root = list_entry(root->root_list.next,
1657                                         struct ctl_table_root, root_list);
1658                         if (root == &sysctl_table_root)
1659                                 goto out;
1660                         header_list = lookup_header_list(root, namespaces);
1661                 } while (list_empty(header_list));
1662                 tmp = header_list->next;
1663         }
1664 out:
1665         spin_unlock(&sysctl_lock);
1666         return NULL;
1667 }
1668
1669 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1670 {
1671         return __sysctl_head_next(current->nsproxy, prev);
1672 }
1673
1674 void register_sysctl_root(struct ctl_table_root *root)
1675 {
1676         spin_lock(&sysctl_lock);
1677         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1678         spin_unlock(&sysctl_lock);
1679 }
1680
1681 #ifdef CONFIG_SYSCTL_SYSCALL
1682 /* Perform the actual read/write of a sysctl table entry. */
1683 static int do_sysctl_strategy(struct ctl_table_root *root,
1684                         struct ctl_table *table,
1685                         void __user *oldval, size_t __user *oldlenp,
1686                         void __user *newval, size_t newlen)
1687 {
1688         int op = 0, rc;
1689
1690         if (oldval)
1691                 op |= MAY_READ;
1692         if (newval)
1693                 op |= MAY_WRITE;
1694         if (sysctl_perm(root, table, op))
1695                 return -EPERM;
1696
1697         if (table->strategy) {
1698                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1699                 if (rc < 0)
1700                         return rc;
1701                 if (rc > 0)
1702                         return 0;
1703         }
1704
1705         /* If there is no strategy routine, or if the strategy returns
1706          * zero, proceed with automatic r/w */
1707         if (table->data && table->maxlen) {
1708                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1709                 if (rc < 0)
1710                         return rc;
1711         }
1712         return 0;
1713 }
1714
1715 static int parse_table(int __user *name, int nlen,
1716                        void __user *oldval, size_t __user *oldlenp,
1717                        void __user *newval, size_t newlen,
1718                        struct ctl_table_root *root,
1719                        struct ctl_table *table)
1720 {
1721         int n;
1722 repeat:
1723         if (!nlen)
1724                 return -ENOTDIR;
1725         if (get_user(n, name))
1726                 return -EFAULT;
1727         for ( ; table->ctl_name || table->procname; table++) {
1728                 if (!table->ctl_name)
1729                         continue;
1730                 if (n == table->ctl_name) {
1731                         int error;
1732                         if (table->child) {
1733                                 if (sysctl_perm(root, table, MAY_EXEC))
1734                                         return -EPERM;
1735                                 name++;
1736                                 nlen--;
1737                                 table = table->child;
1738                                 goto repeat;
1739                         }
1740                         error = do_sysctl_strategy(root, table,
1741                                                    oldval, oldlenp,
1742                                                    newval, newlen);
1743                         return error;
1744                 }
1745         }
1746         return -ENOTDIR;
1747 }
1748
1749 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1750                void __user *newval, size_t newlen)
1751 {
1752         struct ctl_table_header *head;
1753         int error = -ENOTDIR;
1754
1755         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1756                 return -ENOTDIR;
1757         if (oldval) {
1758                 int old_len;
1759                 if (!oldlenp || get_user(old_len, oldlenp))
1760                         return -EFAULT;
1761         }
1762
1763         for (head = sysctl_head_next(NULL); head;
1764                         head = sysctl_head_next(head)) {
1765                 error = parse_table(name, nlen, oldval, oldlenp,
1766                                         newval, newlen,
1767                                         head->root, head->ctl_table);
1768                 if (error != -ENOTDIR) {
1769                         sysctl_head_finish(head);
1770                         break;
1771                 }
1772         }
1773         return error;
1774 }
1775
1776 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1777 {
1778         struct __sysctl_args tmp;
1779         int error;
1780
1781         if (copy_from_user(&tmp, args, sizeof(tmp)))
1782                 return -EFAULT;
1783
1784         error = deprecated_sysctl_warning(&tmp);
1785         if (error)
1786                 goto out;
1787
1788         lock_kernel();
1789         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1790                           tmp.newval, tmp.newlen);
1791         unlock_kernel();
1792 out:
1793         return error;
1794 }
1795 #endif /* CONFIG_SYSCTL_SYSCALL */
1796
1797 /*
1798  * sysctl_perm does NOT grant the superuser all rights automatically, because
1799  * some sysctl variables are readonly even to root.
1800  */
1801
1802 static int test_perm(int mode, int op)
1803 {
1804         if (!current_euid())
1805                 mode >>= 6;
1806         else if (in_egroup_p(0))
1807                 mode >>= 3;
1808         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1809                 return 0;
1810         return -EACCES;
1811 }
1812
1813 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1814 {
1815         int error;
1816         int mode;
1817
1818         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1819         if (error)
1820                 return error;
1821
1822         if (root->permissions)
1823                 mode = root->permissions(root, current->nsproxy, table);
1824         else
1825                 mode = table->mode;
1826
1827         return test_perm(mode, op);
1828 }
1829
1830 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1831 {
1832         for (; table->ctl_name || table->procname; table++) {
1833                 table->parent = parent;
1834                 if (table->child)
1835                         sysctl_set_parent(table, table->child);
1836         }
1837 }
1838
1839 static __init int sysctl_init(void)
1840 {
1841         sysctl_set_parent(NULL, root_table);
1842 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1843         {
1844                 int err;
1845                 err = sysctl_check_table(current->nsproxy, root_table);
1846         }
1847 #endif
1848         return 0;
1849 }
1850
1851 core_initcall(sysctl_init);
1852
1853 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1854                                       struct ctl_table *table)
1855 {
1856         struct ctl_table *p;
1857         const char *s = branch->procname;
1858
1859         /* branch should have named subdirectory as its first element */
1860         if (!s || !branch->child)
1861                 return NULL;
1862
1863         /* ... and nothing else */
1864         if (branch[1].procname || branch[1].ctl_name)
1865                 return NULL;
1866
1867         /* table should contain subdirectory with the same name */
1868         for (p = table; p->procname || p->ctl_name; p++) {
1869                 if (!p->child)
1870                         continue;
1871                 if (p->procname && strcmp(p->procname, s) == 0)
1872                         return p;
1873         }
1874         return NULL;
1875 }
1876
1877 /* see if attaching q to p would be an improvement */
1878 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1879 {
1880         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1881         struct ctl_table *next;
1882         int is_better = 0;
1883         int not_in_parent = !p->attached_by;
1884
1885         while ((next = is_branch_in(by, to)) != NULL) {
1886                 if (by == q->attached_by)
1887                         is_better = 1;
1888                 if (to == p->attached_by)
1889                         not_in_parent = 1;
1890                 by = by->child;
1891                 to = next->child;
1892         }
1893
1894         if (is_better && not_in_parent) {
1895                 q->attached_by = by;
1896                 q->attached_to = to;
1897                 q->parent = p;
1898         }
1899 }
1900
1901 /**
1902  * __register_sysctl_paths - register a sysctl hierarchy
1903  * @root: List of sysctl headers to register on
1904  * @namespaces: Data to compute which lists of sysctl entries are visible
1905  * @path: The path to the directory the sysctl table is in.
1906  * @table: the top-level table structure
1907  *
1908  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1909  * array. A completely 0 filled entry terminates the table.
1910  *
1911  * The members of the &struct ctl_table structure are used as follows:
1912  *
1913  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1914  *            must be unique within that level of sysctl
1915  *
1916  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1917  *            enter a sysctl file
1918  *
1919  * data - a pointer to data for use by proc_handler
1920  *
1921  * maxlen - the maximum size in bytes of the data
1922  *
1923  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1924  *
1925  * child - a pointer to the child sysctl table if this entry is a directory, or
1926  *         %NULL.
1927  *
1928  * proc_handler - the text handler routine (described below)
1929  *
1930  * strategy - the strategy routine (described below)
1931  *
1932  * de - for internal use by the sysctl routines
1933  *
1934  * extra1, extra2 - extra pointers usable by the proc handler routines
1935  *
1936  * Leaf nodes in the sysctl tree will be represented by a single file
1937  * under /proc; non-leaf nodes will be represented by directories.
1938  *
1939  * sysctl(2) can automatically manage read and write requests through
1940  * the sysctl table.  The data and maxlen fields of the ctl_table
1941  * struct enable minimal validation of the values being written to be
1942  * performed, and the mode field allows minimal authentication.
1943  *
1944  * More sophisticated management can be enabled by the provision of a
1945  * strategy routine with the table entry.  This will be called before
1946  * any automatic read or write of the data is performed.
1947  *
1948  * The strategy routine may return
1949  *
1950  * < 0 - Error occurred (error is passed to user process)
1951  *
1952  * 0   - OK - proceed with automatic read or write.
1953  *
1954  * > 0 - OK - read or write has been done by the strategy routine, so
1955  *       return immediately.
1956  *
1957  * There must be a proc_handler routine for any terminal nodes
1958  * mirrored under /proc/sys (non-terminals are handled by a built-in
1959  * directory handler).  Several default handlers are available to
1960  * cover common cases -
1961  *
1962  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1963  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1964  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1965  *
1966  * It is the handler's job to read the input buffer from user memory
1967  * and process it. The handler should return 0 on success.
1968  *
1969  * This routine returns %NULL on a failure to register, and a pointer
1970  * to the table header on success.
1971  */
1972 struct ctl_table_header *__register_sysctl_paths(
1973         struct ctl_table_root *root,
1974         struct nsproxy *namespaces,
1975         const struct ctl_path *path, struct ctl_table *table)
1976 {
1977         struct ctl_table_header *header;
1978         struct ctl_table *new, **prevp;
1979         unsigned int n, npath;
1980         struct ctl_table_set *set;
1981
1982         /* Count the path components */
1983         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1984                 ;
1985
1986         /*
1987          * For each path component, allocate a 2-element ctl_table array.
1988          * The first array element will be filled with the sysctl entry
1989          * for this, the second will be the sentinel (ctl_name == 0).
1990          *
1991          * We allocate everything in one go so that we don't have to
1992          * worry about freeing additional memory in unregister_sysctl_table.
1993          */
1994         header = kzalloc(sizeof(struct ctl_table_header) +
1995                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1996         if (!header)
1997                 return NULL;
1998
1999         new = (struct ctl_table *) (header + 1);
2000
2001         /* Now connect the dots */
2002         prevp = &header->ctl_table;
2003         for (n = 0; n < npath; ++n, ++path) {
2004                 /* Copy the procname */
2005                 new->procname = path->procname;
2006                 new->ctl_name = path->ctl_name;
2007                 new->mode     = 0555;
2008
2009                 *prevp = new;
2010                 prevp = &new->child;
2011
2012                 new += 2;
2013         }
2014         *prevp = table;
2015         header->ctl_table_arg = table;
2016
2017         INIT_LIST_HEAD(&header->ctl_entry);
2018         header->used = 0;
2019         header->unregistering = NULL;
2020         header->root = root;
2021         sysctl_set_parent(NULL, header->ctl_table);
2022         header->count = 1;
2023 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2024         if (sysctl_check_table(namespaces, header->ctl_table)) {
2025                 kfree(header);
2026                 return NULL;
2027         }
2028 #endif
2029         spin_lock(&sysctl_lock);
2030         header->set = lookup_header_set(root, namespaces);
2031         header->attached_by = header->ctl_table;
2032         header->attached_to = root_table;
2033         header->parent = &root_table_header;
2034         for (set = header->set; set; set = set->parent) {
2035                 struct ctl_table_header *p;
2036                 list_for_each_entry(p, &set->list, ctl_entry) {
2037                         if (p->unregistering)
2038                                 continue;
2039                         try_attach(p, header);
2040                 }
2041         }
2042         header->parent->count++;
2043         list_add_tail(&header->ctl_entry, &header->set->list);
2044         spin_unlock(&sysctl_lock);
2045
2046         return header;
2047 }
2048
2049 /**
2050  * register_sysctl_table_path - register a sysctl table hierarchy
2051  * @path: The path to the directory the sysctl table is in.
2052  * @table: the top-level table structure
2053  *
2054  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2055  * array. A completely 0 filled entry terminates the table.
2056  *
2057  * See __register_sysctl_paths for more details.
2058  */
2059 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2060                                                 struct ctl_table *table)
2061 {
2062         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2063                                         path, table);
2064 }
2065
2066 /**
2067  * register_sysctl_table - register a sysctl table hierarchy
2068  * @table: the top-level table structure
2069  *
2070  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2071  * array. A completely 0 filled entry terminates the table.
2072  *
2073  * See register_sysctl_paths for more details.
2074  */
2075 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2076 {
2077         static const struct ctl_path null_path[] = { {} };
2078
2079         return register_sysctl_paths(null_path, table);
2080 }
2081
2082 /**
2083  * unregister_sysctl_table - unregister a sysctl table hierarchy
2084  * @header: the header returned from register_sysctl_table
2085  *
2086  * Unregisters the sysctl table and all children. proc entries may not
2087  * actually be removed until they are no longer used by anyone.
2088  */
2089 void unregister_sysctl_table(struct ctl_table_header * header)
2090 {
2091         might_sleep();
2092
2093         if (header == NULL)
2094                 return;
2095
2096         spin_lock(&sysctl_lock);
2097         start_unregistering(header);
2098         if (!--header->parent->count) {
2099                 WARN_ON(1);
2100                 kfree(header->parent);
2101         }
2102         if (!--header->count)
2103                 kfree(header);
2104         spin_unlock(&sysctl_lock);
2105 }
2106
2107 int sysctl_is_seen(struct ctl_table_header *p)
2108 {
2109         struct ctl_table_set *set = p->set;
2110         int res;
2111         spin_lock(&sysctl_lock);
2112         if (p->unregistering)
2113                 res = 0;
2114         else if (!set->is_seen)
2115                 res = 1;
2116         else
2117                 res = set->is_seen(set);
2118         spin_unlock(&sysctl_lock);
2119         return res;
2120 }
2121
2122 void setup_sysctl_set(struct ctl_table_set *p,
2123         struct ctl_table_set *parent,
2124         int (*is_seen)(struct ctl_table_set *))
2125 {
2126         INIT_LIST_HEAD(&p->list);
2127         p->parent = parent ? parent : &sysctl_table_root.default_set;
2128         p->is_seen = is_seen;
2129 }
2130
2131 #else /* !CONFIG_SYSCTL */
2132 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2133 {
2134         return NULL;
2135 }
2136
2137 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2138                                                     struct ctl_table *table)
2139 {
2140         return NULL;
2141 }
2142
2143 void unregister_sysctl_table(struct ctl_table_header * table)
2144 {
2145 }
2146
2147 void setup_sysctl_set(struct ctl_table_set *p,
2148         struct ctl_table_set *parent,
2149         int (*is_seen)(struct ctl_table_set *))
2150 {
2151 }
2152
2153 void sysctl_head_put(struct ctl_table_header *head)
2154 {
2155 }
2156
2157 #endif /* CONFIG_SYSCTL */
2158
2159 /*
2160  * /proc/sys support
2161  */
2162
2163 #ifdef CONFIG_PROC_SYSCTL
2164
2165 static int _proc_do_string(void* data, int maxlen, int write,
2166                            struct file *filp, void __user *buffer,
2167                            size_t *lenp, loff_t *ppos)
2168 {
2169         size_t len;
2170         char __user *p;
2171         char c;
2172
2173         if (!data || !maxlen || !*lenp) {
2174                 *lenp = 0;
2175                 return 0;
2176         }
2177
2178         if (write) {
2179                 len = 0;
2180                 p = buffer;
2181                 while (len < *lenp) {
2182                         if (get_user(c, p++))
2183                                 return -EFAULT;
2184                         if (c == 0 || c == '\n')
2185                                 break;
2186                         len++;
2187                 }
2188                 if (len >= maxlen)
2189                         len = maxlen-1;
2190                 if(copy_from_user(data, buffer, len))
2191                         return -EFAULT;
2192                 ((char *) data)[len] = 0;
2193                 *ppos += *lenp;
2194         } else {
2195                 len = strlen(data);
2196                 if (len > maxlen)
2197                         len = maxlen;
2198
2199                 if (*ppos > len) {
2200                         *lenp = 0;
2201                         return 0;
2202                 }
2203
2204                 data += *ppos;
2205                 len  -= *ppos;
2206
2207                 if (len > *lenp)
2208                         len = *lenp;
2209                 if (len)
2210                         if(copy_to_user(buffer, data, len))
2211                                 return -EFAULT;
2212                 if (len < *lenp) {
2213                         if(put_user('\n', ((char __user *) buffer) + len))
2214                                 return -EFAULT;
2215                         len++;
2216                 }
2217                 *lenp = len;
2218                 *ppos += len;
2219         }
2220         return 0;
2221 }
2222
2223 /**
2224  * proc_dostring - read a string sysctl
2225  * @table: the sysctl table
2226  * @write: %TRUE if this is a write to the sysctl file
2227  * @filp: the file structure
2228  * @buffer: the user buffer
2229  * @lenp: the size of the user buffer
2230  * @ppos: file position
2231  *
2232  * Reads/writes a string from/to the user buffer. If the kernel
2233  * buffer provided is not large enough to hold the string, the
2234  * string is truncated. The copied string is %NULL-terminated.
2235  * If the string is being read by the user process, it is copied
2236  * and a newline '\n' is added. It is truncated if the buffer is
2237  * not large enough.
2238  *
2239  * Returns 0 on success.
2240  */
2241 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2242                   void __user *buffer, size_t *lenp, loff_t *ppos)
2243 {
2244         return _proc_do_string(table->data, table->maxlen, write, filp,
2245                                buffer, lenp, ppos);
2246 }
2247
2248
2249 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2250                                  int *valp,
2251                                  int write, void *data)
2252 {
2253         if (write) {
2254                 *valp = *negp ? -*lvalp : *lvalp;
2255         } else {
2256                 int val = *valp;
2257                 if (val < 0) {
2258                         *negp = -1;
2259                         *lvalp = (unsigned long)-val;
2260                 } else {
2261                         *negp = 0;
2262                         *lvalp = (unsigned long)val;
2263                 }
2264         }
2265         return 0;
2266 }
2267
2268 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2269                   int write, struct file *filp, void __user *buffer,
2270                   size_t *lenp, loff_t *ppos,
2271                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2272                               int write, void *data),
2273                   void *data)
2274 {
2275 #define TMPBUFLEN 21
2276         int *i, vleft, first=1, neg, val;
2277         unsigned long lval;
2278         size_t left, len;
2279
2280         char buf[TMPBUFLEN], *p;
2281         char __user *s = buffer;
2282
2283         if (!tbl_data || !table->maxlen || !*lenp ||
2284             (*ppos && !write)) {
2285                 *lenp = 0;
2286                 return 0;
2287         }
2288
2289         i = (int *) tbl_data;
2290         vleft = table->maxlen / sizeof(*i);
2291         left = *lenp;
2292
2293         if (!conv)
2294                 conv = do_proc_dointvec_conv;
2295
2296         for (; left && vleft--; i++, first=0) {
2297                 if (write) {
2298                         while (left) {
2299                                 char c;
2300                                 if (get_user(c, s))
2301                                         return -EFAULT;
2302                                 if (!isspace(c))
2303                                         break;
2304                                 left--;
2305                                 s++;
2306                         }
2307                         if (!left)
2308                                 break;
2309                         neg = 0;
2310                         len = left;
2311                         if (len > sizeof(buf) - 1)
2312                                 len = sizeof(buf) - 1;
2313                         if (copy_from_user(buf, s, len))
2314                                 return -EFAULT;
2315                         buf[len] = 0;
2316                         p = buf;
2317                         if (*p == '-' && left > 1) {
2318                                 neg = 1;
2319                                 p++;
2320                         }
2321                         if (*p < '0' || *p > '9')
2322                                 break;
2323
2324                         lval = simple_strtoul(p, &p, 0);
2325
2326                         len = p-buf;
2327                         if ((len < left) && *p && !isspace(*p))
2328                                 break;
2329                         if (neg)
2330                                 val = -val;
2331                         s += len;
2332                         left -= len;
2333
2334                         if (conv(&neg, &lval, i, 1, data))
2335                                 break;
2336                 } else {
2337                         p = buf;
2338                         if (!first)
2339                                 *p++ = '\t';
2340
2341                         if (conv(&neg, &lval, i, 0, data))
2342                                 break;
2343
2344                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2345                         len = strlen(buf);
2346                         if (len > left)
2347                                 len = left;
2348                         if(copy_to_user(s, buf, len))
2349                                 return -EFAULT;
2350                         left -= len;
2351                         s += len;
2352                 }
2353         }
2354
2355         if (!write && !first && left) {
2356                 if(put_user('\n', s))
2357                         return -EFAULT;
2358                 left--, s++;
2359         }
2360         if (write) {
2361                 while (left) {
2362                         char c;
2363                         if (get_user(c, s++))
2364                                 return -EFAULT;
2365                         if (!isspace(c))
2366                                 break;
2367                         left--;
2368                 }
2369         }
2370         if (write && first)
2371                 return -EINVAL;
2372         *lenp -= left;
2373         *ppos += *lenp;
2374         return 0;
2375 #undef TMPBUFLEN
2376 }
2377
2378 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2379                   void __user *buffer, size_t *lenp, loff_t *ppos,
2380                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2381                               int write, void *data),
2382                   void *data)
2383 {
2384         return __do_proc_dointvec(table->data, table, write, filp,
2385                         buffer, lenp, ppos, conv, data);
2386 }
2387
2388 /**
2389  * proc_dointvec - read a vector of integers
2390  * @table: the sysctl table
2391  * @write: %TRUE if this is a write to the sysctl file
2392  * @filp: the file structure
2393  * @buffer: the user buffer
2394  * @lenp: the size of the user buffer
2395  * @ppos: file position
2396  *
2397  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2398  * values from/to the user buffer, treated as an ASCII string.
2399  *
2400  * Returns 0 on success.
2401  */
2402 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2403                      void __user *buffer, size_t *lenp, loff_t *ppos)
2404 {
2405     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2406                             NULL,NULL);
2407 }
2408
2409 /*
2410  * Taint values can only be increased
2411  * This means we can safely use a temporary.
2412  */
2413 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2414                                void __user *buffer, size_t *lenp, loff_t *ppos)
2415 {
2416         struct ctl_table t;
2417         unsigned long tmptaint = get_taint();
2418         int err;
2419
2420         if (write && !capable(CAP_SYS_ADMIN))
2421                 return -EPERM;
2422
2423         t = *table;
2424         t.data = &tmptaint;
2425         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2426         if (err < 0)
2427                 return err;
2428
2429         if (write) {
2430                 /*
2431                  * Poor man's atomic or. Not worth adding a primitive
2432                  * to everyone's atomic.h for this
2433                  */
2434                 int i;
2435                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2436                         if ((tmptaint >> i) & 1)
2437                                 add_taint(i);
2438                 }
2439         }
2440
2441         return err;
2442 }
2443
2444 struct do_proc_dointvec_minmax_conv_param {
2445         int *min;
2446         int *max;
2447 };
2448
2449 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2450                                         int *valp,
2451                                         int write, void *data)
2452 {
2453         struct do_proc_dointvec_minmax_conv_param *param = data;
2454         if (write) {
2455                 int val = *negp ? -*lvalp : *lvalp;
2456                 if ((param->min && *param->min > val) ||
2457                     (param->max && *param->max < val))
2458                         return -EINVAL;
2459                 *valp = val;
2460         } else {
2461                 int val = *valp;
2462                 if (val < 0) {
2463                         *negp = -1;
2464                         *lvalp = (unsigned long)-val;
2465                 } else {
2466                         *negp = 0;
2467                         *lvalp = (unsigned long)val;
2468                 }
2469         }
2470         return 0;
2471 }
2472
2473 /**
2474  * proc_dointvec_minmax - read a vector of integers with min/max values
2475  * @table: the sysctl table
2476  * @write: %TRUE if this is a write to the sysctl file
2477  * @filp: the file structure
2478  * @buffer: the user buffer
2479  * @lenp: the size of the user buffer
2480  * @ppos: file position
2481  *
2482  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2483  * values from/to the user buffer, treated as an ASCII string.
2484  *
2485  * This routine will ensure the values are within the range specified by
2486  * table->extra1 (min) and table->extra2 (max).
2487  *
2488  * Returns 0 on success.
2489  */
2490 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2491                   void __user *buffer, size_t *lenp, loff_t *ppos)
2492 {
2493         struct do_proc_dointvec_minmax_conv_param param = {
2494                 .min = (int *) table->extra1,
2495                 .max = (int *) table->extra2,
2496         };
2497         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2498                                 do_proc_dointvec_minmax_conv, &param);
2499 }
2500
2501 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2502                                      struct file *filp,
2503                                      void __user *buffer,
2504                                      size_t *lenp, loff_t *ppos,
2505                                      unsigned long convmul,
2506                                      unsigned long convdiv)
2507 {
2508 #define TMPBUFLEN 21
2509         unsigned long *i, *min, *max, val;
2510         int vleft, first=1, neg;
2511         size_t len, left;
2512         char buf[TMPBUFLEN], *p;
2513         char __user *s = buffer;
2514
2515         if (!data || !table->maxlen || !*lenp ||
2516             (*ppos && !write)) {
2517                 *lenp = 0;
2518                 return 0;
2519         }
2520
2521         i = (unsigned long *) data;
2522         min = (unsigned long *) table->extra1;
2523         max = (unsigned long *) table->extra2;
2524         vleft = table->maxlen / sizeof(unsigned long);
2525         left = *lenp;
2526
2527         for (; left && vleft--; i++, min++, max++, first=0) {
2528                 if (write) {
2529                         while (left) {
2530                                 char c;
2531                                 if (get_user(c, s))
2532                                         return -EFAULT;
2533                                 if (!isspace(c))
2534                                         break;
2535                                 left--;
2536                                 s++;
2537                         }
2538                         if (!left)
2539                                 break;
2540                         neg = 0;
2541                         len = left;
2542                         if (len > TMPBUFLEN-1)
2543                                 len = TMPBUFLEN-1;
2544                         if (copy_from_user(buf, s, len))
2545                                 return -EFAULT;
2546                         buf[len] = 0;
2547                         p = buf;
2548                         if (*p == '-' && left > 1) {
2549                                 neg = 1;
2550                                 p++;
2551                         }
2552                         if (*p < '0' || *p > '9')
2553                                 break;
2554                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2555                         len = p-buf;
2556                         if ((len < left) && *p && !isspace(*p))
2557                                 break;
2558                         if (neg)
2559                                 val = -val;
2560                         s += len;
2561                         left -= len;
2562
2563                         if(neg)
2564                                 continue;
2565                         if ((min && val < *min) || (max && val > *max))
2566                                 continue;
2567                         *i = val;
2568                 } else {
2569                         p = buf;
2570                         if (!first)
2571                                 *p++ = '\t';
2572                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2573                         len = strlen(buf);
2574                         if (len > left)
2575                                 len = left;
2576                         if(copy_to_user(s, buf, len))
2577                                 return -EFAULT;
2578                         left -= len;
2579                         s += len;
2580                 }
2581         }
2582
2583         if (!write && !first && left) {
2584                 if(put_user('\n', s))
2585                         return -EFAULT;
2586                 left--, s++;
2587         }
2588         if (write) {
2589                 while (left) {
2590                         char c;
2591                         if (get_user(c, s++))
2592                                 return -EFAULT;
2593                         if (!isspace(c))
2594                                 break;
2595                         left--;
2596                 }
2597         }
2598         if (write && first)
2599                 return -EINVAL;
2600         *lenp -= left;
2601         *ppos += *lenp;
2602         return 0;
2603 #undef TMPBUFLEN
2604 }
2605
2606 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2607                                      struct file *filp,
2608                                      void __user *buffer,
2609                                      size_t *lenp, loff_t *ppos,
2610                                      unsigned long convmul,
2611                                      unsigned long convdiv)
2612 {
2613         return __do_proc_doulongvec_minmax(table->data, table, write,
2614                         filp, buffer, lenp, ppos, convmul, convdiv);
2615 }
2616
2617 /**
2618  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2619  * @table: the sysctl table
2620  * @write: %TRUE if this is a write to the sysctl file
2621  * @filp: the file structure
2622  * @buffer: the user buffer
2623  * @lenp: the size of the user buffer
2624  * @ppos: file position
2625  *
2626  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2627  * values from/to the user buffer, treated as an ASCII string.
2628  *
2629  * This routine will ensure the values are within the range specified by
2630  * table->extra1 (min) and table->extra2 (max).
2631  *
2632  * Returns 0 on success.
2633  */
2634 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2635                            void __user *buffer, size_t *lenp, loff_t *ppos)
2636 {
2637     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2638 }
2639
2640 /**
2641  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2642  * @table: the sysctl table
2643  * @write: %TRUE if this is a write to the sysctl file
2644  * @filp: the file structure
2645  * @buffer: the user buffer
2646  * @lenp: the size of the user buffer
2647  * @ppos: file position
2648  *
2649  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2650  * values from/to the user buffer, treated as an ASCII string. The values
2651  * are treated as milliseconds, and converted to jiffies when they are stored.
2652  *
2653  * This routine will ensure the values are within the range specified by
2654  * table->extra1 (min) and table->extra2 (max).
2655  *
2656  * Returns 0 on success.
2657  */
2658 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2659                                       struct file *filp,
2660                                       void __user *buffer,
2661                                       size_t *lenp, loff_t *ppos)
2662 {
2663     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2664                                      lenp, ppos, HZ, 1000l);
2665 }
2666
2667
2668 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2669                                          int *valp,
2670                                          int write, void *data)
2671 {
2672         if (write) {
2673                 if (*lvalp > LONG_MAX / HZ)
2674                         return 1;
2675                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2676         } else {
2677                 int val = *valp;
2678                 unsigned long lval;
2679                 if (val < 0) {
2680                         *negp = -1;
2681                         lval = (unsigned long)-val;
2682                 } else {
2683                         *negp = 0;
2684                         lval = (unsigned long)val;
2685                 }
2686                 *lvalp = lval / HZ;
2687         }
2688         return 0;
2689 }
2690
2691 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2692                                                 int *valp,
2693                                                 int write, void *data)
2694 {
2695         if (write) {
2696                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2697                         return 1;
2698                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2699         } else {
2700                 int val = *valp;
2701                 unsigned long lval;
2702                 if (val < 0) {
2703                         *negp = -1;
2704                         lval = (unsigned long)-val;
2705                 } else {
2706                         *negp = 0;
2707                         lval = (unsigned long)val;
2708                 }
2709                 *lvalp = jiffies_to_clock_t(lval);
2710         }
2711         return 0;
2712 }
2713
2714 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2715                                             int *valp,
2716                                             int write, void *data)
2717 {
2718         if (write) {
2719                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2720         } else {
2721                 int val = *valp;
2722                 unsigned long lval;
2723                 if (val < 0) {
2724                         *negp = -1;
2725                         lval = (unsigned long)-val;
2726                 } else {
2727                         *negp = 0;
2728                         lval = (unsigned long)val;
2729                 }
2730                 *lvalp = jiffies_to_msecs(lval);
2731         }
2732         return 0;
2733 }
2734
2735 /**
2736  * proc_dointvec_jiffies - read a vector of integers as seconds
2737  * @table: the sysctl table
2738  * @write: %TRUE if this is a write to the sysctl file
2739  * @filp: the file structure
2740  * @buffer: the user buffer
2741  * @lenp: the size of the user buffer
2742  * @ppos: file position
2743  *
2744  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2745  * values from/to the user buffer, treated as an ASCII string.
2746  * The values read are assumed to be in seconds, and are converted into
2747  * jiffies.
2748  *
2749  * Returns 0 on success.
2750  */
2751 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2752                           void __user *buffer, size_t *lenp, loff_t *ppos)
2753 {
2754     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2755                             do_proc_dointvec_jiffies_conv,NULL);
2756 }
2757
2758 /**
2759  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2760  * @table: the sysctl table
2761  * @write: %TRUE if this is a write to the sysctl file
2762  * @filp: the file structure
2763  * @buffer: the user buffer
2764  * @lenp: the size of the user buffer
2765  * @ppos: pointer to the file position
2766  *
2767  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2768  * values from/to the user buffer, treated as an ASCII string.
2769  * The values read are assumed to be in 1/USER_HZ seconds, and
2770  * are converted into jiffies.
2771  *
2772  * Returns 0 on success.
2773  */
2774 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2775                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2776 {
2777     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2778                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2779 }
2780
2781 /**
2782  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2783  * @table: the sysctl table
2784  * @write: %TRUE if this is a write to the sysctl file
2785  * @filp: the file structure
2786  * @buffer: the user buffer
2787  * @lenp: the size of the user buffer
2788  * @ppos: file position
2789  * @ppos: the current position in the file
2790  *
2791  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2792  * values from/to the user buffer, treated as an ASCII string.
2793  * The values read are assumed to be in 1/1000 seconds, and
2794  * are converted into jiffies.
2795  *
2796  * Returns 0 on success.
2797  */
2798 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2799                              void __user *buffer, size_t *lenp, loff_t *ppos)
2800 {
2801         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2802                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2803 }
2804
2805 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2806                            void __user *buffer, size_t *lenp, loff_t *ppos)
2807 {
2808         struct pid *new_pid;
2809         pid_t tmp;
2810         int r;
2811
2812         tmp = pid_vnr(cad_pid);
2813
2814         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2815                                lenp, ppos, NULL, NULL);
2816         if (r || !write)
2817                 return r;
2818
2819         new_pid = find_get_pid(tmp);
2820         if (!new_pid)
2821                 return -ESRCH;
2822
2823         put_pid(xchg(&cad_pid, new_pid));
2824         return 0;
2825 }
2826
2827 #else /* CONFIG_PROC_FS */
2828
2829 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2830                   void __user *buffer, size_t *lenp, loff_t *ppos)
2831 {
2832         return -ENOSYS;
2833 }
2834
2835 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2836                   void __user *buffer, size_t *lenp, loff_t *ppos)
2837 {
2838         return -ENOSYS;
2839 }
2840
2841 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2842                     void __user *buffer, size_t *lenp, loff_t *ppos)
2843 {
2844         return -ENOSYS;
2845 }
2846
2847 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2848                     void __user *buffer, size_t *lenp, loff_t *ppos)
2849 {
2850         return -ENOSYS;
2851 }
2852
2853 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2854                     void __user *buffer, size_t *lenp, loff_t *ppos)
2855 {
2856         return -ENOSYS;
2857 }
2858
2859 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2860                              void __user *buffer, size_t *lenp, loff_t *ppos)
2861 {
2862         return -ENOSYS;
2863 }
2864
2865 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2866                     void __user *buffer, size_t *lenp, loff_t *ppos)
2867 {
2868         return -ENOSYS;
2869 }
2870
2871 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2872                                       struct file *filp,
2873                                       void __user *buffer,
2874                                       size_t *lenp, loff_t *ppos)
2875 {
2876     return -ENOSYS;
2877 }
2878
2879
2880 #endif /* CONFIG_PROC_FS */
2881
2882
2883 #ifdef CONFIG_SYSCTL_SYSCALL
2884 /*
2885  * General sysctl support routines
2886  */
2887
2888 /* The generic sysctl data routine (used if no strategy routine supplied) */
2889 int sysctl_data(struct ctl_table *table,
2890                 void __user *oldval, size_t __user *oldlenp,
2891                 void __user *newval, size_t newlen)
2892 {
2893         size_t len;
2894
2895         /* Get out of I don't have a variable */
2896         if (!table->data || !table->maxlen)
2897                 return -ENOTDIR;
2898
2899         if (oldval && oldlenp) {
2900                 if (get_user(len, oldlenp))
2901                         return -EFAULT;
2902                 if (len) {
2903                         if (len > table->maxlen)
2904                                 len = table->maxlen;
2905                         if (copy_to_user(oldval, table->data, len))
2906                                 return -EFAULT;
2907                         if (put_user(len, oldlenp))
2908                                 return -EFAULT;
2909                 }
2910         }
2911
2912         if (newval && newlen) {
2913                 if (newlen > table->maxlen)
2914                         newlen = table->maxlen;
2915
2916                 if (copy_from_user(table->data, newval, newlen))
2917                         return -EFAULT;
2918         }
2919         return 1;
2920 }
2921
2922 /* The generic string strategy routine: */
2923 int sysctl_string(struct ctl_table *table,
2924                   void __user *oldval, size_t __user *oldlenp,
2925                   void __user *newval, size_t newlen)
2926 {
2927         if (!table->data || !table->maxlen)
2928                 return -ENOTDIR;
2929
2930         if (oldval && oldlenp) {
2931                 size_t bufsize;
2932                 if (get_user(bufsize, oldlenp))
2933                         return -EFAULT;
2934                 if (bufsize) {
2935                         size_t len = strlen(table->data), copied;
2936
2937                         /* This shouldn't trigger for a well-formed sysctl */
2938                         if (len > table->maxlen)
2939                                 len = table->maxlen;
2940
2941                         /* Copy up to a max of bufsize-1 bytes of the string */
2942                         copied = (len >= bufsize) ? bufsize - 1 : len;
2943
2944                         if (copy_to_user(oldval, table->data, copied) ||
2945                             put_user(0, (char __user *)(oldval + copied)))
2946                                 return -EFAULT;
2947                         if (put_user(len, oldlenp))
2948                                 return -EFAULT;
2949                 }
2950         }
2951         if (newval && newlen) {
2952                 size_t len = newlen;
2953                 if (len > table->maxlen)
2954                         len = table->maxlen;
2955                 if(copy_from_user(table->data, newval, len))
2956                         return -EFAULT;
2957                 if (len == table->maxlen)
2958                         len--;
2959                 ((char *) table->data)[len] = 0;
2960         }
2961         return 1;
2962 }
2963
2964 /*
2965  * This function makes sure that all of the integers in the vector
2966  * are between the minimum and maximum values given in the arrays
2967  * table->extra1 and table->extra2, respectively.
2968  */
2969 int sysctl_intvec(struct ctl_table *table,
2970                 void __user *oldval, size_t __user *oldlenp,
2971                 void __user *newval, size_t newlen)
2972 {
2973
2974         if (newval && newlen) {
2975                 int __user *vec = (int __user *) newval;
2976                 int *min = (int *) table->extra1;
2977                 int *max = (int *) table->extra2;
2978                 size_t length;
2979                 int i;
2980
2981                 if (newlen % sizeof(int) != 0)
2982                         return -EINVAL;
2983
2984                 if (!table->extra1 && !table->extra2)
2985                         return 0;
2986
2987                 if (newlen > table->maxlen)
2988                         newlen = table->maxlen;
2989                 length = newlen / sizeof(int);
2990
2991                 for (i = 0; i < length; i++) {
2992                         int value;
2993                         if (get_user(value, vec + i))
2994                                 return -EFAULT;
2995                         if (min && value < min[i])
2996                                 return -EINVAL;
2997                         if (max && value > max[i])
2998                                 return -EINVAL;
2999                 }
3000         }
3001         return 0;
3002 }
3003
3004 /* Strategy function to convert jiffies to seconds */
3005 int sysctl_jiffies(struct ctl_table *table,
3006                 void __user *oldval, size_t __user *oldlenp,
3007                 void __user *newval, size_t newlen)
3008 {
3009         if (oldval && oldlenp) {
3010                 size_t olen;
3011
3012                 if (get_user(olen, oldlenp))
3013                         return -EFAULT;
3014                 if (olen) {
3015                         int val;
3016
3017                         if (olen < sizeof(int))
3018                                 return -EINVAL;
3019
3020                         val = *(int *)(table->data) / HZ;
3021                         if (put_user(val, (int __user *)oldval))
3022                                 return -EFAULT;
3023                         if (put_user(sizeof(int), oldlenp))
3024                                 return -EFAULT;
3025                 }
3026         }
3027         if (newval && newlen) {
3028                 int new;
3029                 if (newlen != sizeof(int))
3030                         return -EINVAL;
3031                 if (get_user(new, (int __user *)newval))
3032                         return -EFAULT;
3033                 *(int *)(table->data) = new*HZ;
3034         }
3035         return 1;
3036 }
3037
3038 /* Strategy function to convert jiffies to seconds */
3039 int sysctl_ms_jiffies(struct ctl_table *table,
3040                 void __user *oldval, size_t __user *oldlenp,
3041                 void __user *newval, size_t newlen)
3042 {
3043         if (oldval && oldlenp) {
3044                 size_t olen;
3045
3046                 if (get_user(olen, oldlenp))
3047                         return -EFAULT;
3048                 if (olen) {
3049                         int val;
3050
3051                         if (olen < sizeof(int))
3052                                 return -EINVAL;
3053
3054                         val = jiffies_to_msecs(*(int *)(table->data));
3055                         if (put_user(val, (int __user *)oldval))
3056                                 return -EFAULT;
3057                         if (put_user(sizeof(int), oldlenp))
3058                                 return -EFAULT;
3059                 }
3060         }
3061         if (newval && newlen) {
3062                 int new;
3063                 if (newlen != sizeof(int))
3064                         return -EINVAL;
3065                 if (get_user(new, (int __user *)newval))
3066                         return -EFAULT;
3067                 *(int *)(table->data) = msecs_to_jiffies(new);
3068         }
3069         return 1;
3070 }
3071
3072
3073
3074 #else /* CONFIG_SYSCTL_SYSCALL */
3075
3076
3077 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3078 {
3079         struct __sysctl_args tmp;
3080         int error;
3081
3082         if (copy_from_user(&tmp, args, sizeof(tmp)))
3083                 return -EFAULT;
3084
3085         error = deprecated_sysctl_warning(&tmp);
3086
3087         /* If no error reading the parameters then just -ENOSYS ... */
3088         if (!error)
3089                 error = -ENOSYS;
3090
3091         return error;
3092 }
3093
3094 int sysctl_data(struct ctl_table *table,
3095                   void __user *oldval, size_t __user *oldlenp,
3096                   void __user *newval, size_t newlen)
3097 {
3098         return -ENOSYS;
3099 }
3100
3101 int sysctl_string(struct ctl_table *table,
3102                   void __user *oldval, size_t __user *oldlenp,
3103                   void __user *newval, size_t newlen)
3104 {
3105         return -ENOSYS;
3106 }
3107
3108 int sysctl_intvec(struct ctl_table *table,
3109                 void __user *oldval, size_t __user *oldlenp,
3110                 void __user *newval, size_t newlen)
3111 {
3112         return -ENOSYS;
3113 }
3114
3115 int sysctl_jiffies(struct ctl_table *table,
3116                 void __user *oldval, size_t __user *oldlenp,
3117                 void __user *newval, size_t newlen)
3118 {
3119         return -ENOSYS;
3120 }
3121
3122 int sysctl_ms_jiffies(struct ctl_table *table,
3123                 void __user *oldval, size_t __user *oldlenp,
3124                 void __user *newval, size_t newlen)
3125 {
3126         return -ENOSYS;
3127 }
3128
3129 #endif /* CONFIG_SYSCTL_SYSCALL */
3130
3131 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3132 {
3133         static int msg_count;
3134         int name[CTL_MAXNAME];
3135         int i;
3136
3137         /* Check args->nlen. */
3138         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3139                 return -ENOTDIR;
3140
3141         /* Read in the sysctl name for better debug message logging */
3142         for (i = 0; i < args->nlen; i++)
3143                 if (get_user(name[i], args->name + i))
3144                         return -EFAULT;
3145
3146         /* Ignore accesses to kernel.version */
3147         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3148                 return 0;
3149
3150         if (msg_count < 5) {
3151                 msg_count++;
3152                 printk(KERN_INFO
3153                         "warning: process `%s' used the deprecated sysctl "
3154                         "system call with ", current->comm);
3155                 for (i = 0; i < args->nlen; i++)
3156                         printk("%d.", name[i]);
3157                 printk("\n");
3158         }
3159         return 0;
3160 }
3161
3162 /*
3163  * No sense putting this after each symbol definition, twice,
3164  * exception granted :-)
3165  */
3166 EXPORT_SYMBOL(proc_dointvec);
3167 EXPORT_SYMBOL(proc_dointvec_jiffies);
3168 EXPORT_SYMBOL(proc_dointvec_minmax);
3169 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3170 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3171 EXPORT_SYMBOL(proc_dostring);
3172 EXPORT_SYMBOL(proc_doulongvec_minmax);
3173 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3174 EXPORT_SYMBOL(register_sysctl_table);
3175 EXPORT_SYMBOL(register_sysctl_paths);
3176 EXPORT_SYMBOL(sysctl_intvec);
3177 EXPORT_SYMBOL(sysctl_jiffies);
3178 EXPORT_SYMBOL(sysctl_ms_jiffies);
3179 EXPORT_SYMBOL(sysctl_string);
3180 EXPORT_SYMBOL(sysctl_data);
3181 EXPORT_SYMBOL(unregister_sysctl_table);