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/kmemcheck.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_counter.h>
  54
  55 #include <asm/uaccess.h>
  56 #include <asm/processor.h>
  57
  58 #ifdef CONFIG_X86
  59 #include <asm/nmi.h>
  60 #include <asm/stacktrace.h>
  61 #include <asm/io.h>
  62 #endif
  63
  64 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  65
  66 #if defined(CONFIG_SYSCTL)
  67
  68 /* External variables not in a header file. */
  69 extern int C_A_D;
  70 extern int print_fatal_signals;
  71 extern int sysctl_overcommit_memory;
  72 extern int sysctl_overcommit_ratio;
  73 extern int sysctl_panic_on_oom;
  74 extern int sysctl_oom_kill_allocating_task;
  75 extern int sysctl_oom_dump_tasks;
  76 extern int max_threads;
  77 extern int core_uses_pid;
  78 extern int suid_dumpable;
  79 extern char core_pattern[];
  80 extern int pid_max;
  81 extern int min_free_kbytes;
  82 extern int pid_max_min, pid_max_max;
  83 extern int sysctl_drop_caches;
  84 extern int percpu_pagelist_fraction;
  85 extern int compat_log;
  86 extern int latencytop_enabled;
  87 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  88 #ifndef CONFIG_MMU
  89 extern int sysctl_nr_trim_pages;
  90 #endif
  91 #ifdef CONFIG_RCU_TORTURE_TEST
  92 extern int rcutorture_runnable;
  93 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  94 extern int blk_iopoll_enabled;
  95
  96 /* Constants used for minimum and  maximum */
  97 #ifdef CONFIG_DETECT_SOFTLOCKUP
  98 static int sixty = 60;
  99 static int neg_one = -1;
 100 #endif
 101
 102 static int zero;
 103 static int __maybe_unused one = 1;
 104 static int __maybe_unused two = 2;
 105 static unsigned long one_ul = 1;
 106 static int one_hundred = 100;
 107
 108 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 109 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 110
 111 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 112 static int maxolduid = 65535;
 113 static int minolduid;
 114 static int min_percpu_pagelist_fract = 8;
 115
 116 static int ngroups_max = NGROUPS_MAX;
 117
 118 #ifdef CONFIG_MODULES
 119 extern char modprobe_path[];
 120 extern int modules_disabled;
 121 #endif
 122 #ifdef CONFIG_CHR_DEV_SG
 123 extern int sg_big_buff;
 124 #endif
 125
 126 #ifdef CONFIG_SPARC
 127 #include <asm/system.h>
 128 #endif
 129
 130 #ifdef CONFIG_SPARC64
 131 extern int sysctl_tsb_ratio;
 132 #endif
 133
 134 #ifdef __hppa__
 135 extern int pwrsw_enabled;
 136 extern int unaligned_enabled;
 137 #endif
 138
 139 #ifdef CONFIG_S390
 140 #ifdef CONFIG_MATHEMU
 141 extern int sysctl_ieee_emulation_warnings;
 142 #endif
 143 extern int sysctl_userprocess_debug;
 144 extern int spin_retry;
 145 #endif
 146
 147 #ifdef CONFIG_BSD_PROCESS_ACCT
 148 extern int acct_parm[];
 149 #endif
 150
 151 #ifdef CONFIG_IA64
 152 extern int no_unaligned_warning;
 153 extern int unaligned_dump_stack;
 154 #endif
 155
 156 #ifdef CONFIG_RT_MUTEXES
 157 extern int max_lock_depth;
 158 #endif
 159
 160 #ifdef CONFIG_PROC_SYSCTL
 161 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 162                   void __user *buffer, size_t *lenp, loff_t *ppos);
 163 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 164                                void __user *buffer, size_t *lenp, loff_t *ppos);
 165 #endif
 166
 167 static struct ctl_table root_table[];
 168 static struct ctl_table_root sysctl_table_root;
 169 static struct ctl_table_header root_table_header = {
 170         .count = 1,
 171         .ctl_table = root_table,
 172         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 173         .root = &sysctl_table_root,
 174         .set = &sysctl_table_root.default_set,
 175 };
 176 static struct ctl_table_root sysctl_table_root = {
 177         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 178         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 179 };
 180
 181 static struct ctl_table kern_table[];
 182 static struct ctl_table vm_table[];
 183 static struct ctl_table fs_table[];
 184 static struct ctl_table debug_table[];
 185 static struct ctl_table dev_table[];
 186 extern struct ctl_table random_table[];
 187 #ifdef CONFIG_INOTIFY_USER
 188 extern struct ctl_table inotify_table[];
 189 #endif
 190 #ifdef CONFIG_EPOLL
 191 extern struct ctl_table epoll_table[];
 192 #endif
 193
 194 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 195 int sysctl_legacy_va_layout;
 196 #endif
 197
 198 extern int prove_locking;
 199 extern int lock_stat;
 200
 201 /* The default sysctl tables: */
 202
 203 static struct ctl_table root_table[] = {
 204         {
 205                 .ctl_name       = CTL_KERN,
 206                 .procname       = "kernel",
 207                 .mode           = 0555,
 208                 .child          = kern_table,
 209         },
 210         {
 211                 .ctl_name       = CTL_VM,
 212                 .procname       = "vm",
 213                 .mode           = 0555,
 214                 .child          = vm_table,
 215         },
 216         {
 217                 .ctl_name       = CTL_FS,
 218                 .procname       = "fs",
 219                 .mode           = 0555,
 220                 .child          = fs_table,
 221         },
 222         {
 223                 .ctl_name       = CTL_DEBUG,
 224                 .procname       = "debug",
 225                 .mode           = 0555,
 226                 .child          = debug_table,
 227         },
 228         {
 229                 .ctl_name       = CTL_DEV,
 230                 .procname       = "dev",
 231                 .mode           = 0555,
 232                 .child          = dev_table,
 233         },
 234 /*
 235  * NOTE: do not add new entries to this table unless you have read
 236  * Documentation/sysctl/ctl_unnumbered.txt
 237  */
 238         { .ctl_name = 0 }
 239 };
 240
 241 #ifdef CONFIG_SCHED_DEBUG
 242 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 243 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 244 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 245 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 246 #endif
 247
 248 static struct ctl_table kern_table[] = {
 249         {
 250                 .ctl_name       = CTL_UNNUMBERED,
 251                 .procname       = "sched_child_runs_first",
 252                 .data           = &sysctl_sched_child_runs_first,
 253                 .maxlen         = sizeof(unsigned int),
 254                 .mode           = 0644,
 255                 .proc_handler   = &proc_dointvec,
 256         },
 257 #ifdef CONFIG_SCHED_DEBUG
 258         {
 259                 .ctl_name       = CTL_UNNUMBERED,
 260                 .procname       = "sched_min_granularity_ns",
 261                 .data           = &sysctl_sched_min_granularity,
 262                 .maxlen         = sizeof(unsigned int),
 263                 .mode           = 0644,
 264                 .proc_handler   = &sched_nr_latency_handler,
 265                 .strategy       = &sysctl_intvec,
 266                 .extra1         = &min_sched_granularity_ns,
 267                 .extra2         = &max_sched_granularity_ns,
 268         },
 269         {
 270                 .ctl_name       = CTL_UNNUMBERED,
 271                 .procname       = "sched_latency_ns",
 272                 .data           = &sysctl_sched_latency,
 273                 .maxlen         = sizeof(unsigned int),
 274                 .mode           = 0644,
 275                 .proc_handler   = &sched_nr_latency_handler,
 276                 .strategy       = &sysctl_intvec,
 277                 .extra1         = &min_sched_granularity_ns,
 278                 .extra2         = &max_sched_granularity_ns,
 279         },
 280         {
 281                 .ctl_name       = CTL_UNNUMBERED,
 282                 .procname       = "sched_wakeup_granularity_ns",
 283                 .data           = &sysctl_sched_wakeup_granularity,
 284                 .maxlen         = sizeof(unsigned int),
 285                 .mode           = 0644,
 286                 .proc_handler   = &proc_dointvec_minmax,
 287                 .strategy       = &sysctl_intvec,
 288                 .extra1         = &min_wakeup_granularity_ns,
 289                 .extra2         = &max_wakeup_granularity_ns,
 290         },
 291         {
 292                 .ctl_name       = CTL_UNNUMBERED,
 293                 .procname       = "sched_shares_ratelimit",
 294                 .data           = &sysctl_sched_shares_ratelimit,
 295                 .maxlen         = sizeof(unsigned int),
 296                 .mode           = 0644,
 297                 .proc_handler   = &proc_dointvec,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_shares_thresh",
 302                 .data           = &sysctl_sched_shares_thresh,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec_minmax,
 306                 .strategy       = &sysctl_intvec,
 307                 .extra1         = &zero,
 308         },
 309         {
 310                 .ctl_name       = CTL_UNNUMBERED,
 311                 .procname       = "sched_features",
 312                 .data           = &sysctl_sched_features,
 313                 .maxlen         = sizeof(unsigned int),
 314                 .mode           = 0644,
 315                 .proc_handler   = &proc_dointvec,
 316         },
 317         {
 318                 .ctl_name       = CTL_UNNUMBERED,
 319                 .procname       = "sched_migration_cost",
 320                 .data           = &sysctl_sched_migration_cost,
 321                 .maxlen         = sizeof(unsigned int),
 322                 .mode           = 0644,
 323                 .proc_handler   = &proc_dointvec,
 324         },
 325         {
 326                 .ctl_name       = CTL_UNNUMBERED,
 327                 .procname       = "sched_nr_migrate",
 328                 .data           = &sysctl_sched_nr_migrate,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = &proc_dointvec,
 332         },
 333         {
 334                 .ctl_name       = CTL_UNNUMBERED,
 335                 .procname       = "sched_time_avg",
 336                 .data           = &sysctl_sched_time_avg,
 337                 .maxlen         = sizeof(unsigned int),
 338                 .mode           = 0644,
 339                 .proc_handler   = &proc_dointvec,
 340         },
 341         {
 342                 .ctl_name       = CTL_UNNUMBERED,
 343                 .procname       = "timer_migration",
 344                 .data           = &sysctl_timer_migration,
 345                 .maxlen         = sizeof(unsigned int),
 346                 .mode           = 0644,
 347                 .proc_handler   = &proc_dointvec_minmax,
 348                 .strategy       = &sysctl_intvec,
 349                 .extra1         = &zero,
 350                 .extra2         = &one,
 351         },
 352 #endif
 353         {
 354                 .ctl_name       = CTL_UNNUMBERED,
 355                 .procname       = "sched_rt_period_us",
 356                 .data           = &sysctl_sched_rt_period,
 357                 .maxlen         = sizeof(unsigned int),
 358                 .mode           = 0644,
 359                 .proc_handler   = &sched_rt_handler,
 360         },
 361         {
 362                 .ctl_name       = CTL_UNNUMBERED,
 363                 .procname       = "sched_rt_runtime_us",
 364                 .data           = &sysctl_sched_rt_runtime,
 365                 .maxlen         = sizeof(int),
 366                 .mode           = 0644,
 367                 .proc_handler   = &sched_rt_handler,
 368         },
 369         {
 370                 .ctl_name       = CTL_UNNUMBERED,
 371                 .procname       = "sched_compat_yield",
 372                 .data           = &sysctl_sched_compat_yield,
 373                 .maxlen         = sizeof(unsigned int),
 374                 .mode           = 0644,
 375                 .proc_handler   = &proc_dointvec,
 376         },
 377 #ifdef CONFIG_PROVE_LOCKING
 378         {
 379                 .ctl_name       = CTL_UNNUMBERED,
 380                 .procname       = "prove_locking",
 381                 .data           = &prove_locking,
 382                 .maxlen         = sizeof(int),
 383                 .mode           = 0644,
 384                 .proc_handler   = &proc_dointvec,
 385         },
 386 #endif
 387 #ifdef CONFIG_LOCK_STAT
 388         {
 389                 .ctl_name       = CTL_UNNUMBERED,
 390                 .procname       = "lock_stat",
 391                 .data           = &lock_stat,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = &proc_dointvec,
 395         },
 396 #endif
 397         {
 398                 .ctl_name       = KERN_PANIC,
 399                 .procname       = "panic",
 400                 .data           = &panic_timeout,
 401                 .maxlen         = sizeof(int),
 402                 .mode           = 0644,
 403                 .proc_handler   = &proc_dointvec,
 404         },
 405         {
 406                 .ctl_name       = KERN_CORE_USES_PID,
 407                 .procname       = "core_uses_pid",
 408                 .data           = &core_uses_pid,
 409                 .maxlen         = sizeof(int),
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dointvec,
 412         },
 413         {
 414                 .ctl_name       = KERN_CORE_PATTERN,
 415                 .procname       = "core_pattern",
 416                 .data           = core_pattern,
 417                 .maxlen         = CORENAME_MAX_SIZE,
 418                 .mode           = 0644,
 419                 .proc_handler   = &proc_dostring,
 420                 .strategy       = &sysctl_string,
 421         },
 422 #ifdef CONFIG_PROC_SYSCTL
 423         {
 424                 .procname       = "tainted",
 425                 .maxlen         = sizeof(long),
 426                 .mode           = 0644,
 427                 .proc_handler   = &proc_taint,
 428         },
 429 #endif
 430 #ifdef CONFIG_LATENCYTOP
 431         {
 432                 .procname       = "latencytop",
 433                 .data           = &latencytop_enabled,
 434                 .maxlen         = sizeof(int),
 435                 .mode           = 0644,
 436                 .proc_handler   = &proc_dointvec,
 437         },
 438 #endif
 439 #ifdef CONFIG_BLK_DEV_INITRD
 440         {
 441                 .ctl_name       = KERN_REALROOTDEV,
 442                 .procname       = "real-root-dev",
 443                 .data           = &real_root_dev,
 444                 .maxlen         = sizeof(int),
 445                 .mode           = 0644,
 446                 .proc_handler   = &proc_dointvec,
 447         },
 448 #endif
 449         {
 450                 .ctl_name       = CTL_UNNUMBERED,
 451                 .procname       = "print-fatal-signals",
 452                 .data           = &print_fatal_signals,
 453                 .maxlen         = sizeof(int),
 454                 .mode           = 0644,
 455                 .proc_handler   = &proc_dointvec,
 456         },
 457 #ifdef CONFIG_SPARC
 458         {
 459                 .ctl_name       = KERN_SPARC_REBOOT,
 460                 .procname       = "reboot-cmd",
 461                 .data           = reboot_command,
 462                 .maxlen         = 256,
 463                 .mode           = 0644,
 464                 .proc_handler   = &proc_dostring,
 465                 .strategy       = &sysctl_string,
 466         },
 467         {
 468                 .ctl_name       = KERN_SPARC_STOP_A,
 469                 .procname       = "stop-a",
 470                 .data           = &stop_a_enabled,
 471                 .maxlen         = sizeof (int),
 472                 .mode           = 0644,
 473                 .proc_handler   = &proc_dointvec,
 474         },
 475         {
 476                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 477                 .procname       = "scons-poweroff",
 478                 .data           = &scons_pwroff,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = &proc_dointvec,
 482         },
 483 #endif
 484 #ifdef CONFIG_SPARC64
 485         {
 486                 .ctl_name       = CTL_UNNUMBERED,
 487                 .procname       = "tsb-ratio",
 488                 .data           = &sysctl_tsb_ratio,
 489                 .maxlen         = sizeof (int),
 490                 .mode           = 0644,
 491                 .proc_handler   = &proc_dointvec,
 492         },
 493 #endif
 494 #ifdef __hppa__
 495         {
 496                 .ctl_name       = KERN_HPPA_PWRSW,
 497                 .procname       = "soft-power",
 498                 .data           = &pwrsw_enabled,
 499                 .maxlen         = sizeof (int),
 500                 .mode           = 0644,
 501                 .proc_handler   = &proc_dointvec,
 502         },
 503         {
 504                 .ctl_name       = KERN_HPPA_UNALIGNED,
 505                 .procname       = "unaligned-trap",
 506                 .data           = &unaligned_enabled,
 507                 .maxlen         = sizeof (int),
 508                 .mode           = 0644,
 509                 .proc_handler   = &proc_dointvec,
 510         },
 511 #endif
 512         {
 513                 .ctl_name       = KERN_CTLALTDEL,
 514                 .procname       = "ctrl-alt-del",
 515                 .data           = &C_A_D,
 516                 .maxlen         = sizeof(int),
 517                 .mode           = 0644,
 518                 .proc_handler   = &proc_dointvec,
 519         },
 520 #ifdef CONFIG_FUNCTION_TRACER
 521         {
 522                 .ctl_name       = CTL_UNNUMBERED,
 523                 .procname       = "ftrace_enabled",
 524                 .data           = &ftrace_enabled,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = &ftrace_enable_sysctl,
 528         },
 529 #endif
 530 #ifdef CONFIG_STACK_TRACER
 531         {
 532                 .ctl_name       = CTL_UNNUMBERED,
 533                 .procname       = "stack_tracer_enabled",
 534                 .data           = &stack_tracer_enabled,
 535                 .maxlen         = sizeof(int),
 536                 .mode           = 0644,
 537                 .proc_handler   = &stack_trace_sysctl,
 538         },
 539 #endif
 540 #ifdef CONFIG_TRACING
 541         {
 542                 .ctl_name       = CTL_UNNUMBERED,
 543                 .procname       = "ftrace_dump_on_oops",
 544                 .data           = &ftrace_dump_on_oops,
 545                 .maxlen         = sizeof(int),
 546                 .mode           = 0644,
 547                 .proc_handler   = &proc_dointvec,
 548         },
 549 #endif
 550 #ifdef CONFIG_MODULES
 551         {
 552                 .ctl_name       = KERN_MODPROBE,
 553                 .procname       = "modprobe",
 554                 .data           = &modprobe_path,
 555                 .maxlen         = KMOD_PATH_LEN,
 556                 .mode           = 0644,
 557                 .proc_handler   = &proc_dostring,
 558                 .strategy       = &sysctl_string,
 559         },
 560         {
 561                 .ctl_name       = CTL_UNNUMBERED,
 562                 .procname       = "modules_disabled",
 563                 .data           = &modules_disabled,
 564                 .maxlen         = sizeof(int),
 565                 .mode           = 0644,
 566                 /* only handle a transition from default "0" to "1" */
 567                 .proc_handler   = &proc_dointvec_minmax,
 568                 .extra1         = &one,
 569                 .extra2         = &one,
 570         },
 571 #endif
 572 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 573         {
 574                 .ctl_name       = KERN_HOTPLUG,
 575                 .procname       = "hotplug",
 576                 .data           = &uevent_helper,
 577                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dostring,
 580                 .strategy       = &sysctl_string,
 581         },
 582 #endif
 583 #ifdef CONFIG_CHR_DEV_SG
 584         {
 585                 .ctl_name       = KERN_SG_BIG_BUFF,
 586                 .procname       = "sg-big-buff",
 587                 .data           = &sg_big_buff,
 588                 .maxlen         = sizeof (int),
 589                 .mode           = 0444,
 590                 .proc_handler   = &proc_dointvec,
 591         },
 592 #endif
 593 #ifdef CONFIG_BSD_PROCESS_ACCT
 594         {
 595                 .ctl_name       = KERN_ACCT,
 596                 .procname       = "acct",
 597                 .data           = &acct_parm,
 598                 .maxlen         = 3*sizeof(int),
 599                 .mode           = 0644,
 600                 .proc_handler   = &proc_dointvec,
 601         },
 602 #endif
 603 #ifdef CONFIG_MAGIC_SYSRQ
 604         {
 605                 .ctl_name       = KERN_SYSRQ,
 606                 .procname       = "sysrq",
 607                 .data           = &__sysrq_enabled,
 608                 .maxlen         = sizeof (int),
 609                 .mode           = 0644,
 610                 .proc_handler   = &proc_dointvec,
 611         },
 612 #endif
 613 #ifdef CONFIG_PROC_SYSCTL
 614         {
 615                 .procname       = "cad_pid",
 616                 .data           = NULL,
 617                 .maxlen         = sizeof (int),
 618                 .mode           = 0600,
 619                 .proc_handler   = &proc_do_cad_pid,
 620         },
 621 #endif
 622         {
 623                 .ctl_name       = KERN_MAX_THREADS,
 624                 .procname       = "threads-max",
 625                 .data           = &max_threads,
 626                 .maxlen         = sizeof(int),
 627                 .mode           = 0644,
 628                 .proc_handler   = &proc_dointvec,
 629         },
 630         {
 631                 .ctl_name       = KERN_RANDOM,
 632                 .procname       = "random",
 633                 .mode           = 0555,
 634                 .child          = random_table,
 635         },
 636         {
 637                 .ctl_name       = KERN_OVERFLOWUID,
 638                 .procname       = "overflowuid",
 639                 .data           = &overflowuid,
 640                 .maxlen         = sizeof(int),
 641                 .mode           = 0644,
 642                 .proc_handler   = &proc_dointvec_minmax,
 643                 .strategy       = &sysctl_intvec,
 644                 .extra1         = &minolduid,
 645                 .extra2         = &maxolduid,
 646         },
 647         {
 648                 .ctl_name       = KERN_OVERFLOWGID,
 649                 .procname       = "overflowgid",
 650                 .data           = &overflowgid,
 651                 .maxlen         = sizeof(int),
 652                 .mode           = 0644,
 653                 .proc_handler   = &proc_dointvec_minmax,
 654                 .strategy       = &sysctl_intvec,
 655                 .extra1         = &minolduid,
 656                 .extra2         = &maxolduid,
 657         },
 658 #ifdef CONFIG_S390
 659 #ifdef CONFIG_MATHEMU
 660         {
 661                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 662                 .procname       = "ieee_emulation_warnings",
 663                 .data           = &sysctl_ieee_emulation_warnings,
 664                 .maxlen         = sizeof(int),
 665                 .mode           = 0644,
 666                 .proc_handler   = &proc_dointvec,
 667         },
 668 #endif
 669         {
 670                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 671                 .procname       = "userprocess_debug",
 672                 .data           = &sysctl_userprocess_debug,
 673                 .maxlen         = sizeof(int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678         {
 679                 .ctl_name       = KERN_PIDMAX,
 680                 .procname       = "pid_max",
 681                 .data           = &pid_max,
 682                 .maxlen         = sizeof (int),
 683                 .mode           = 0644,
 684                 .proc_handler   = &proc_dointvec_minmax,
 685                 .strategy       = sysctl_intvec,
 686                 .extra1         = &pid_max_min,
 687                 .extra2         = &pid_max_max,
 688         },
 689         {
 690                 .ctl_name       = KERN_PANIC_ON_OOPS,
 691                 .procname       = "panic_on_oops",
 692                 .data           = &panic_on_oops,
 693                 .maxlen         = sizeof(int),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_dointvec,
 696         },
 697 #if defined CONFIG_PRINTK
 698         {
 699                 .ctl_name       = KERN_PRINTK,
 700                 .procname       = "printk",
 701                 .data           = &console_loglevel,
 702                 .maxlen         = 4*sizeof(int),
 703                 .mode           = 0644,
 704                 .proc_handler   = &proc_dointvec,
 705         },
 706         {
 707                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 708                 .procname       = "printk_ratelimit",
 709                 .data           = &printk_ratelimit_state.interval,
 710                 .maxlen         = sizeof(int),
 711                 .mode           = 0644,
 712                 .proc_handler   = &proc_dointvec_jiffies,
 713                 .strategy       = &sysctl_jiffies,
 714         },
 715         {
 716                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 717                 .procname       = "printk_ratelimit_burst",
 718                 .data           = &printk_ratelimit_state.burst,
 719                 .maxlen         = sizeof(int),
 720                 .mode           = 0644,
 721                 .proc_handler   = &proc_dointvec,
 722         },
 723 #endif
 724         {
 725                 .ctl_name       = KERN_NGROUPS_MAX,
 726                 .procname       = "ngroups_max",
 727                 .data           = &ngroups_max,
 728                 .maxlen         = sizeof (int),
 729                 .mode           = 0444,
 730                 .proc_handler   = &proc_dointvec,
 731         },
 732 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 733         {
 734                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 735                 .procname       = "unknown_nmi_panic",
 736                 .data           = &unknown_nmi_panic,
 737                 .maxlen         = sizeof (int),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec,
 740         },
 741         {
 742                 .procname       = "nmi_watchdog",
 743                 .data           = &nmi_watchdog_enabled,
 744                 .maxlen         = sizeof (int),
 745                 .mode           = 0644,
 746                 .proc_handler   = &proc_nmi_enabled,
 747         },
 748 #endif
 749 #if defined(CONFIG_X86)
 750         {
 751                 .ctl_name       = KERN_PANIC_ON_NMI,
 752                 .procname       = "panic_on_unrecovered_nmi",
 753                 .data           = &panic_on_unrecovered_nmi,
 754                 .maxlen         = sizeof(int),
 755                 .mode           = 0644,
 756                 .proc_handler   = &proc_dointvec,
 757         },
 758         {
 759                 .ctl_name       = CTL_UNNUMBERED,
 760                 .procname       = "panic_on_io_nmi",
 761                 .data           = &panic_on_io_nmi,
 762                 .maxlen         = sizeof(int),
 763                 .mode           = 0644,
 764                 .proc_handler   = &proc_dointvec,
 765         },
 766         {
 767                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 768                 .procname       = "bootloader_type",
 769                 .data           = &bootloader_type,
 770                 .maxlen         = sizeof (int),
 771                 .mode           = 0444,
 772                 .proc_handler   = &proc_dointvec,
 773         },
 774         {
 775                 .ctl_name       = CTL_UNNUMBERED,
 776                 .procname       = "bootloader_version",
 777                 .data           = &bootloader_version,
 778                 .maxlen         = sizeof (int),
 779                 .mode           = 0444,
 780                 .proc_handler   = &proc_dointvec,
 781         },
 782         {
 783                 .ctl_name       = CTL_UNNUMBERED,
 784                 .procname       = "kstack_depth_to_print",
 785                 .data           = &kstack_depth_to_print,
 786                 .maxlen         = sizeof(int),
 787                 .mode           = 0644,
 788                 .proc_handler   = &proc_dointvec,
 789         },
 790         {
 791                 .ctl_name       = CTL_UNNUMBERED,
 792                 .procname       = "io_delay_type",
 793                 .data           = &io_delay_type,
 794                 .maxlen         = sizeof(int),
 795                 .mode           = 0644,
 796                 .proc_handler   = &proc_dointvec,
 797         },
 798 #endif
 799 #if defined(CONFIG_MMU)
 800         {
 801                 .ctl_name       = KERN_RANDOMIZE,
 802                 .procname       = "randomize_va_space",
 803                 .data           = &randomize_va_space,
 804                 .maxlen         = sizeof(int),
 805                 .mode           = 0644,
 806                 .proc_handler   = &proc_dointvec,
 807         },
 808 #endif
 809 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 810         {
 811                 .ctl_name       = KERN_SPIN_RETRY,
 812                 .procname       = "spin_retry",
 813                 .data           = &spin_retry,
 814                 .maxlen         = sizeof (int),
 815                 .mode           = 0644,
 816                 .proc_handler   = &proc_dointvec,
 817         },
 818 #endif
 819 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 820         {
 821                 .procname       = "acpi_video_flags",
 822                 .data           = &acpi_realmode_flags,
 823                 .maxlen         = sizeof (unsigned long),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_doulongvec_minmax,
 826         },
 827 #endif
 828 #ifdef CONFIG_IA64
 829         {
 830                 .ctl_name       = KERN_IA64_UNALIGNED,
 831                 .procname       = "ignore-unaligned-usertrap",
 832                 .data           = &no_unaligned_warning,
 833                 .maxlen         = sizeof (int),
 834                 .mode           = 0644,
 835                 .proc_handler   = &proc_dointvec,
 836         },
 837         {
 838                 .ctl_name       = CTL_UNNUMBERED,
 839                 .procname       = "unaligned-dump-stack",
 840                 .data           = &unaligned_dump_stack,
 841                 .maxlen         = sizeof (int),
 842                 .mode           = 0644,
 843                 .proc_handler   = &proc_dointvec,
 844         },
 845 #endif
 846 #ifdef CONFIG_DETECT_SOFTLOCKUP
 847         {
 848                 .ctl_name       = CTL_UNNUMBERED,
 849                 .procname       = "softlockup_panic",
 850                 .data           = &softlockup_panic,
 851                 .maxlen         = sizeof(int),
 852                 .mode           = 0644,
 853                 .proc_handler   = &proc_dointvec_minmax,
 854                 .strategy       = &sysctl_intvec,
 855                 .extra1         = &zero,
 856                 .extra2         = &one,
 857         },
 858         {
 859                 .ctl_name       = CTL_UNNUMBERED,
 860                 .procname       = "softlockup_thresh",
 861                 .data           = &softlockup_thresh,
 862                 .maxlen         = sizeof(int),
 863                 .mode           = 0644,
 864                 .proc_handler   = &proc_dosoftlockup_thresh,
 865                 .strategy       = &sysctl_intvec,
 866                 .extra1         = &neg_one,
 867                 .extra2         = &sixty,
 868         },
 869 #endif
 870 #ifdef CONFIG_DETECT_HUNG_TASK
 871         {
 872                 .ctl_name       = CTL_UNNUMBERED,
 873                 .procname       = "hung_task_panic",
 874                 .data           = &sysctl_hung_task_panic,
 875                 .maxlen         = sizeof(int),
 876                 .mode           = 0644,
 877                 .proc_handler   = &proc_dointvec_minmax,
 878                 .strategy       = &sysctl_intvec,
 879                 .extra1         = &zero,
 880                 .extra2         = &one,
 881         },
 882         {
 883                 .ctl_name       = CTL_UNNUMBERED,
 884                 .procname       = "hung_task_check_count",
 885                 .data           = &sysctl_hung_task_check_count,
 886                 .maxlen         = sizeof(unsigned long),
 887                 .mode           = 0644,
 888                 .proc_handler   = &proc_doulongvec_minmax,
 889                 .strategy       = &sysctl_intvec,
 890         },
 891         {
 892                 .ctl_name       = CTL_UNNUMBERED,
 893                 .procname       = "hung_task_timeout_secs",
 894                 .data           = &sysctl_hung_task_timeout_secs,
 895                 .maxlen         = sizeof(unsigned long),
 896                 .mode           = 0644,
 897                 .proc_handler   = &proc_dohung_task_timeout_secs,
 898                 .strategy       = &sysctl_intvec,
 899         },
 900         {
 901                 .ctl_name       = CTL_UNNUMBERED,
 902                 .procname       = "hung_task_warnings",
 903                 .data           = &sysctl_hung_task_warnings,
 904                 .maxlen         = sizeof(unsigned long),
 905                 .mode           = 0644,
 906                 .proc_handler   = &proc_doulongvec_minmax,
 907                 .strategy       = &sysctl_intvec,
 908         },
 909 #endif
 910 #ifdef CONFIG_COMPAT
 911         {
 912                 .ctl_name       = KERN_COMPAT_LOG,
 913                 .procname       = "compat-log",
 914                 .data           = &compat_log,
 915                 .maxlen         = sizeof (int),
 916                 .mode           = 0644,
 917                 .proc_handler   = &proc_dointvec,
 918         },
 919 #endif
 920 #ifdef CONFIG_RT_MUTEXES
 921         {
 922                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 923                 .procname       = "max_lock_depth",
 924                 .data           = &max_lock_depth,
 925                 .maxlen         = sizeof(int),
 926                 .mode           = 0644,
 927                 .proc_handler   = &proc_dointvec,
 928         },
 929 #endif
 930         {
 931                 .ctl_name       = CTL_UNNUMBERED,
 932                 .procname       = "poweroff_cmd",
 933                 .data           = &poweroff_cmd,
 934                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 935                 .mode           = 0644,
 936                 .proc_handler   = &proc_dostring,
 937                 .strategy       = &sysctl_string,
 938         },
 939 #ifdef CONFIG_KEYS
 940         {
 941                 .ctl_name       = CTL_UNNUMBERED,
 942                 .procname       = "keys",
 943                 .mode           = 0555,
 944                 .child          = key_sysctls,
 945         },
 946 #endif
 947 #ifdef CONFIG_RCU_TORTURE_TEST
 948         {
 949                 .ctl_name       = CTL_UNNUMBERED,
 950                 .procname       = "rcutorture_runnable",
 951                 .data           = &rcutorture_runnable,
 952                 .maxlen         = sizeof(int),
 953                 .mode           = 0644,
 954                 .proc_handler   = &proc_dointvec,
 955         },
 956 #endif
 957 #ifdef CONFIG_SLOW_WORK
 958         {
 959                 .ctl_name       = CTL_UNNUMBERED,
 960                 .procname       = "slow-work",
 961                 .mode           = 0555,
 962                 .child          = slow_work_sysctls,
 963         },
 964 #endif
 965 #ifdef CONFIG_PERF_COUNTERS
 966         {
 967                 .ctl_name       = CTL_UNNUMBERED,
 968                 .procname       = "perf_counter_paranoid",
 969                 .data           = &sysctl_perf_counter_paranoid,
 970                 .maxlen         = sizeof(sysctl_perf_counter_paranoid),
 971                 .mode           = 0644,
 972                 .proc_handler   = &proc_dointvec,
 973         },
 974         {
 975                 .ctl_name       = CTL_UNNUMBERED,
 976                 .procname       = "perf_counter_mlock_kb",
 977                 .data           = &sysctl_perf_counter_mlock,
 978                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
 979                 .mode           = 0644,
 980                 .proc_handler   = &proc_dointvec,
 981         },
 982         {
 983                 .ctl_name       = CTL_UNNUMBERED,
 984                 .procname       = "perf_counter_max_sample_rate",
 985                 .data           = &sysctl_perf_counter_sample_rate,
 986                 .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
 987                 .mode           = 0644,
 988                 .proc_handler   = &proc_dointvec,
 989         },
 990 #endif
 991 #ifdef CONFIG_KMEMCHECK
 992         {
 993                 .ctl_name       = CTL_UNNUMBERED,
 994                 .procname       = "kmemcheck",
 995                 .data           = &kmemcheck_enabled,
 996                 .maxlen         = sizeof(int),
 997                 .mode           = 0644,
 998                 .proc_handler   = &proc_dointvec,
 999         },
1000 #endif
1001         {
1002                 .ctl_name       = CTL_UNNUMBERED,
1003                 .procname       = "blk_iopoll",
1004                 .data           = &blk_iopoll_enabled,
1005                 .maxlen         = sizeof(int),
1006                 .mode           = 0644,
1007                 .proc_handler   = &proc_dointvec,
1008         },
1009 /*
1010  * NOTE: do not add new entries to this table unless you have read
1011  * Documentation/sysctl/ctl_unnumbered.txt
1012  */
1013         { .ctl_name = 0 }
1014 };
1015
1016 static struct ctl_table vm_table[] = {
1017         {
1018                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
1019                 .procname       = "overcommit_memory",
1020                 .data           = &sysctl_overcommit_memory,
1021                 .maxlen         = sizeof(sysctl_overcommit_memory),
1022                 .mode           = 0644,
1023                 .proc_handler   = &proc_dointvec,
1024         },
1025         {
1026                 .ctl_name       = VM_PANIC_ON_OOM,
1027                 .procname       = "panic_on_oom",
1028                 .data           = &sysctl_panic_on_oom,
1029                 .maxlen         = sizeof(sysctl_panic_on_oom),
1030                 .mode           = 0644,
1031                 .proc_handler   = &proc_dointvec,
1032         },
1033         {
1034                 .ctl_name       = CTL_UNNUMBERED,
1035                 .procname       = "oom_kill_allocating_task",
1036                 .data           = &sysctl_oom_kill_allocating_task,
1037                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1038                 .mode           = 0644,
1039                 .proc_handler   = &proc_dointvec,
1040         },
1041         {
1042                 .ctl_name       = CTL_UNNUMBERED,
1043                 .procname       = "oom_dump_tasks",
1044                 .data           = &sysctl_oom_dump_tasks,
1045                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1046                 .mode           = 0644,
1047                 .proc_handler   = &proc_dointvec,
1048         },
1049         {
1050                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1051                 .procname       = "overcommit_ratio",
1052                 .data           = &sysctl_overcommit_ratio,
1053                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1054                 .mode           = 0644,
1055                 .proc_handler   = &proc_dointvec,
1056         },
1057         {
1058                 .ctl_name       = VM_PAGE_CLUSTER,
1059                 .procname       = "page-cluster",
1060                 .data           = &page_cluster,
1061                 .maxlen         = sizeof(int),
1062                 .mode           = 0644,
1063                 .proc_handler   = &proc_dointvec,
1064         },
1065         {
1066                 .ctl_name       = VM_DIRTY_BACKGROUND,
1067                 .procname       = "dirty_background_ratio",
1068                 .data           = &dirty_background_ratio,
1069                 .maxlen         = sizeof(dirty_background_ratio),
1070                 .mode           = 0644,
1071                 .proc_handler   = &dirty_background_ratio_handler,
1072                 .strategy       = &sysctl_intvec,
1073                 .extra1         = &zero,
1074                 .extra2         = &one_hundred,
1075         },
1076         {
1077                 .ctl_name       = CTL_UNNUMBERED,
1078                 .procname       = "dirty_background_bytes",
1079                 .data           = &dirty_background_bytes,
1080                 .maxlen         = sizeof(dirty_background_bytes),
1081                 .mode           = 0644,
1082                 .proc_handler   = &dirty_background_bytes_handler,
1083                 .strategy       = &sysctl_intvec,
1084                 .extra1         = &one_ul,
1085         },
1086         {
1087                 .ctl_name       = VM_DIRTY_RATIO,
1088                 .procname       = "dirty_ratio",
1089                 .data           = &vm_dirty_ratio,
1090                 .maxlen         = sizeof(vm_dirty_ratio),
1091                 .mode           = 0644,
1092                 .proc_handler   = &dirty_ratio_handler,
1093                 .strategy       = &sysctl_intvec,
1094                 .extra1         = &zero,
1095                 .extra2         = &one_hundred,
1096         },
1097         {
1098                 .ctl_name       = CTL_UNNUMBERED,
1099                 .procname       = "dirty_bytes",
1100                 .data           = &vm_dirty_bytes,
1101                 .maxlen         = sizeof(vm_dirty_bytes),
1102                 .mode           = 0644,
1103                 .proc_handler   = &dirty_bytes_handler,
1104                 .strategy       = &sysctl_intvec,
1105                 .extra1         = &dirty_bytes_min,
1106         },
1107         {
1108                 .procname       = "dirty_writeback_centisecs",
1109                 .data           = &dirty_writeback_interval,
1110                 .maxlen         = sizeof(dirty_writeback_interval),
1111                 .mode           = 0644,
1112                 .proc_handler   = &dirty_writeback_centisecs_handler,
1113         },
1114         {
1115                 .procname       = "dirty_expire_centisecs",
1116                 .data           = &dirty_expire_interval,
1117                 .maxlen         = sizeof(dirty_expire_interval),
1118                 .mode           = 0644,
1119                 .proc_handler   = &proc_dointvec,
1120         },
1121         {
1122                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1123                 .procname       = "nr_pdflush_threads",
1124                 .data           = &nr_pdflush_threads,
1125                 .maxlen         = sizeof nr_pdflush_threads,
1126                 .mode           = 0444 /* read-only*/,
1127                 .proc_handler   = &proc_dointvec,
1128         },
1129         {
1130                 .ctl_name       = VM_SWAPPINESS,
1131                 .procname       = "swappiness",
1132                 .data           = &vm_swappiness,
1133                 .maxlen         = sizeof(vm_swappiness),
1134                 .mode           = 0644,
1135                 .proc_handler   = &proc_dointvec_minmax,
1136                 .strategy       = &sysctl_intvec,
1137                 .extra1         = &zero,
1138                 .extra2         = &one_hundred,
1139         },
1140 #ifdef CONFIG_HUGETLB_PAGE
1141          {
1142                 .procname       = "nr_hugepages",
1143                 .data           = NULL,
1144                 .maxlen         = sizeof(unsigned long),
1145                 .mode           = 0644,
1146                 .proc_handler   = &hugetlb_sysctl_handler,
1147                 .extra1         = (void *)&hugetlb_zero,
1148                 .extra2         = (void *)&hugetlb_infinity,
1149          },
1150          {
1151                 .ctl_name       = VM_HUGETLB_GROUP,
1152                 .procname       = "hugetlb_shm_group",
1153                 .data           = &sysctl_hugetlb_shm_group,
1154                 .maxlen         = sizeof(gid_t),
1155                 .mode           = 0644,
1156                 .proc_handler   = &proc_dointvec,
1157          },
1158          {
1159                 .ctl_name       = CTL_UNNUMBERED,
1160                 .procname       = "hugepages_treat_as_movable",
1161                 .data           = &hugepages_treat_as_movable,
1162                 .maxlen         = sizeof(int),
1163                 .mode           = 0644,
1164                 .proc_handler   = &hugetlb_treat_movable_handler,
1165         },
1166         {
1167                 .ctl_name       = CTL_UNNUMBERED,
1168                 .procname       = "nr_overcommit_hugepages",
1169                 .data           = NULL,
1170                 .maxlen         = sizeof(unsigned long),
1171                 .mode           = 0644,
1172                 .proc_handler   = &hugetlb_overcommit_handler,
1173                 .extra1         = (void *)&hugetlb_zero,
1174                 .extra2         = (void *)&hugetlb_infinity,
1175         },
1176 #endif
1177         {
1178                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1179                 .procname       = "lowmem_reserve_ratio",
1180                 .data           = &sysctl_lowmem_reserve_ratio,
1181                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1182                 .mode           = 0644,
1183                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1184                 .strategy       = &sysctl_intvec,
1185         },
1186         {
1187                 .ctl_name       = VM_DROP_PAGECACHE,
1188                 .procname       = "drop_caches",
1189                 .data           = &sysctl_drop_caches,
1190                 .maxlen         = sizeof(int),
1191                 .mode           = 0644,
1192                 .proc_handler   = drop_caches_sysctl_handler,
1193                 .strategy       = &sysctl_intvec,
1194         },
1195         {
1196                 .ctl_name       = VM_MIN_FREE_KBYTES,
1197                 .procname       = "min_free_kbytes",
1198                 .data           = &min_free_kbytes,
1199                 .maxlen         = sizeof(min_free_kbytes),
1200                 .mode           = 0644,
1201                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1202                 .strategy       = &sysctl_intvec,
1203                 .extra1         = &zero,
1204         },
1205         {
1206                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1207                 .procname       = "percpu_pagelist_fraction",
1208                 .data           = &percpu_pagelist_fraction,
1209                 .maxlen         = sizeof(percpu_pagelist_fraction),
1210                 .mode           = 0644,
1211                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1212                 .strategy       = &sysctl_intvec,
1213                 .extra1         = &min_percpu_pagelist_fract,
1214         },
1215 #ifdef CONFIG_MMU
1216         {
1217                 .ctl_name       = VM_MAX_MAP_COUNT,
1218                 .procname       = "max_map_count",
1219                 .data           = &sysctl_max_map_count,
1220                 .maxlen         = sizeof(sysctl_max_map_count),
1221                 .mode           = 0644,
1222                 .proc_handler   = &proc_dointvec
1223         },
1224 #else
1225         {
1226                 .ctl_name       = CTL_UNNUMBERED,
1227                 .procname       = "nr_trim_pages",
1228                 .data           = &sysctl_nr_trim_pages,
1229                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1230                 .mode           = 0644,
1231                 .proc_handler   = &proc_dointvec_minmax,
1232                 .strategy       = &sysctl_intvec,
1233                 .extra1         = &zero,
1234         },
1235 #endif
1236         {
1237                 .ctl_name       = VM_LAPTOP_MODE,
1238                 .procname       = "laptop_mode",
1239                 .data           = &laptop_mode,
1240                 .maxlen         = sizeof(laptop_mode),
1241                 .mode           = 0644,
1242                 .proc_handler   = &proc_dointvec_jiffies,
1243                 .strategy       = &sysctl_jiffies,
1244         },
1245         {
1246                 .ctl_name       = VM_BLOCK_DUMP,
1247                 .procname       = "block_dump",
1248                 .data           = &block_dump,
1249                 .maxlen         = sizeof(block_dump),
1250                 .mode           = 0644,
1251                 .proc_handler   = &proc_dointvec,
1252                 .strategy       = &sysctl_intvec,
1253                 .extra1         = &zero,
1254         },
1255         {
1256                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1257                 .procname       = "vfs_cache_pressure",
1258                 .data           = &sysctl_vfs_cache_pressure,
1259                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1260                 .mode           = 0644,
1261                 .proc_handler   = &proc_dointvec,
1262                 .strategy       = &sysctl_intvec,
1263                 .extra1         = &zero,
1264         },
1265 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1266         {
1267                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1268                 .procname       = "legacy_va_layout",
1269                 .data           = &sysctl_legacy_va_layout,
1270                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1271                 .mode           = 0644,
1272                 .proc_handler   = &proc_dointvec,
1273                 .strategy       = &sysctl_intvec,
1274                 .extra1         = &zero,
1275         },
1276 #endif
1277 #ifdef CONFIG_NUMA
1278         {
1279                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1280                 .procname       = "zone_reclaim_mode",
1281                 .data           = &zone_reclaim_mode,
1282                 .maxlen         = sizeof(zone_reclaim_mode),
1283                 .mode           = 0644,
1284                 .proc_handler   = &proc_dointvec,
1285                 .strategy       = &sysctl_intvec,
1286                 .extra1         = &zero,
1287         },
1288         {
1289                 .ctl_name       = VM_MIN_UNMAPPED,
1290                 .procname       = "min_unmapped_ratio",
1291                 .data           = &sysctl_min_unmapped_ratio,
1292                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1293                 .mode           = 0644,
1294                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1295                 .strategy       = &sysctl_intvec,
1296                 .extra1         = &zero,
1297                 .extra2         = &one_hundred,
1298         },
1299         {
1300                 .ctl_name       = VM_MIN_SLAB,
1301                 .procname       = "min_slab_ratio",
1302                 .data           = &sysctl_min_slab_ratio,
1303                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1304                 .mode           = 0644,
1305                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1306                 .strategy       = &sysctl_intvec,
1307                 .extra1         = &zero,
1308                 .extra2         = &one_hundred,
1309         },
1310 #endif
1311 #ifdef CONFIG_SMP
1312         {
1313                 .ctl_name       = CTL_UNNUMBERED,
1314                 .procname       = "stat_interval",
1315                 .data           = &sysctl_stat_interval,
1316                 .maxlen         = sizeof(sysctl_stat_interval),
1317                 .mode           = 0644,
1318                 .proc_handler   = &proc_dointvec_jiffies,
1319                 .strategy       = &sysctl_jiffies,
1320         },
1321 #endif
1322         {
1323                 .ctl_name       = CTL_UNNUMBERED,
1324                 .procname       = "mmap_min_addr",
1325                 .data           = &dac_mmap_min_addr,
1326                 .maxlen         = sizeof(unsigned long),
1327                 .mode           = 0644,
1328                 .proc_handler   = &mmap_min_addr_handler,
1329         },
1330 #ifdef CONFIG_NUMA
1331         {
1332                 .ctl_name       = CTL_UNNUMBERED,
1333                 .procname       = "numa_zonelist_order",
1334                 .data           = &numa_zonelist_order,
1335                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1336                 .mode           = 0644,
1337                 .proc_handler   = &numa_zonelist_order_handler,
1338                 .strategy       = &sysctl_string,
1339         },
1340 #endif
1341 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1342    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1343         {
1344                 .ctl_name       = VM_VDSO_ENABLED,
1345                 .procname       = "vdso_enabled",
1346                 .data           = &vdso_enabled,
1347                 .maxlen         = sizeof(vdso_enabled),
1348                 .mode           = 0644,
1349                 .proc_handler   = &proc_dointvec,
1350                 .strategy       = &sysctl_intvec,
1351                 .extra1         = &zero,
1352         },
1353 #endif
1354 #ifdef CONFIG_HIGHMEM
1355         {
1356                 .ctl_name       = CTL_UNNUMBERED,
1357                 .procname       = "highmem_is_dirtyable",
1358                 .data           = &vm_highmem_is_dirtyable,
1359                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1360                 .mode           = 0644,
1361                 .proc_handler   = &proc_dointvec_minmax,
1362                 .strategy       = &sysctl_intvec,
1363                 .extra1         = &zero,
1364                 .extra2         = &one,
1365         },
1366 #endif
1367         {
1368                 .ctl_name       = CTL_UNNUMBERED,
1369                 .procname       = "scan_unevictable_pages",
1370                 .data           = &scan_unevictable_pages,
1371                 .maxlen         = sizeof(scan_unevictable_pages),
1372                 .mode           = 0644,
1373                 .proc_handler   = &scan_unevictable_handler,
1374         },
1375 /*
1376  * NOTE: do not add new entries to this table unless you have read
1377  * Documentation/sysctl/ctl_unnumbered.txt
1378  */
1379         { .ctl_name = 0 }
1380 };
1381
1382 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1383 static struct ctl_table binfmt_misc_table[] = {
1384         { .ctl_name = 0 }
1385 };
1386 #endif
1387
1388 static struct ctl_table fs_table[] = {
1389         {
1390                 .ctl_name       = FS_NRINODE,
1391                 .procname       = "inode-nr",
1392                 .data           = &inodes_stat,
1393                 .maxlen         = 2*sizeof(int),
1394                 .mode           = 0444,
1395                 .proc_handler   = &proc_dointvec,
1396         },
1397         {
1398                 .ctl_name       = FS_STATINODE,
1399                 .procname       = "inode-state",
1400                 .data           = &inodes_stat,
1401                 .maxlen         = 7*sizeof(int),
1402                 .mode           = 0444,
1403                 .proc_handler   = &proc_dointvec,
1404         },
1405         {
1406                 .procname       = "file-nr",
1407                 .data           = &files_stat,
1408                 .maxlen         = 3*sizeof(int),
1409                 .mode           = 0444,
1410                 .proc_handler   = &proc_nr_files,
1411         },
1412         {
1413                 .ctl_name       = FS_MAXFILE,
1414                 .procname       = "file-max",
1415                 .data           = &files_stat.max_files,
1416                 .maxlen         = sizeof(int),
1417                 .mode           = 0644,
1418                 .proc_handler   = &proc_dointvec,
1419         },
1420         {
1421                 .ctl_name       = CTL_UNNUMBERED,
1422                 .procname       = "nr_open",
1423                 .data           = &sysctl_nr_open,
1424                 .maxlen         = sizeof(int),
1425                 .mode           = 0644,
1426                 .proc_handler   = &proc_dointvec_minmax,
1427                 .extra1         = &sysctl_nr_open_min,
1428                 .extra2         = &sysctl_nr_open_max,
1429         },
1430         {
1431                 .ctl_name       = FS_DENTRY,
1432                 .procname       = "dentry-state",
1433                 .data           = &dentry_stat,
1434                 .maxlen         = 6*sizeof(int),
1435                 .mode           = 0444,
1436                 .proc_handler   = &proc_dointvec,
1437         },
1438         {
1439                 .ctl_name       = FS_OVERFLOWUID,
1440                 .procname       = "overflowuid",
1441                 .data           = &fs_overflowuid,
1442                 .maxlen         = sizeof(int),
1443                 .mode           = 0644,
1444                 .proc_handler   = &proc_dointvec_minmax,
1445                 .strategy       = &sysctl_intvec,
1446                 .extra1         = &minolduid,
1447                 .extra2         = &maxolduid,
1448         },
1449         {
1450                 .ctl_name       = FS_OVERFLOWGID,
1451                 .procname       = "overflowgid",
1452                 .data           = &fs_overflowgid,
1453                 .maxlen         = sizeof(int),
1454                 .mode           = 0644,
1455                 .proc_handler   = &proc_dointvec_minmax,
1456                 .strategy       = &sysctl_intvec,
1457                 .extra1         = &minolduid,
1458                 .extra2         = &maxolduid,
1459         },
1460 #ifdef CONFIG_FILE_LOCKING
1461         {
1462                 .ctl_name       = FS_LEASES,
1463                 .procname       = "leases-enable",
1464                 .data           = &leases_enable,
1465                 .maxlen         = sizeof(int),
1466                 .mode           = 0644,
1467                 .proc_handler   = &proc_dointvec,
1468         },
1469 #endif
1470 #ifdef CONFIG_DNOTIFY
1471         {
1472                 .ctl_name       = FS_DIR_NOTIFY,
1473                 .procname       = "dir-notify-enable",
1474                 .data           = &dir_notify_enable,
1475                 .maxlen         = sizeof(int),
1476                 .mode           = 0644,
1477                 .proc_handler   = &proc_dointvec,
1478         },
1479 #endif
1480 #ifdef CONFIG_MMU
1481 #ifdef CONFIG_FILE_LOCKING
1482         {
1483                 .ctl_name       = FS_LEASE_TIME,
1484                 .procname       = "lease-break-time",
1485                 .data           = &lease_break_time,
1486                 .maxlen         = sizeof(int),
1487                 .mode           = 0644,
1488                 .proc_handler   = &proc_dointvec,
1489         },
1490 #endif
1491 #ifdef CONFIG_AIO
1492         {
1493                 .procname       = "aio-nr",
1494                 .data           = &aio_nr,
1495                 .maxlen         = sizeof(aio_nr),
1496                 .mode           = 0444,
1497                 .proc_handler   = &proc_doulongvec_minmax,
1498         },
1499         {
1500                 .procname       = "aio-max-nr",
1501                 .data           = &aio_max_nr,
1502                 .maxlen         = sizeof(aio_max_nr),
1503                 .mode           = 0644,
1504                 .proc_handler   = &proc_doulongvec_minmax,
1505         },
1506 #endif /* CONFIG_AIO */
1507 #ifdef CONFIG_INOTIFY_USER
1508         {
1509                 .ctl_name       = FS_INOTIFY,
1510                 .procname       = "inotify",
1511                 .mode           = 0555,
1512                 .child          = inotify_table,
1513         },
1514 #endif
1515 #ifdef CONFIG_EPOLL
1516         {
1517                 .procname       = "epoll",
1518                 .mode           = 0555,
1519                 .child          = epoll_table,
1520         },
1521 #endif
1522 #endif
1523         {
1524                 .ctl_name       = KERN_SETUID_DUMPABLE,
1525                 .procname       = "suid_dumpable",
1526                 .data           = &suid_dumpable,
1527                 .maxlen         = sizeof(int),
1528                 .mode           = 0644,
1529                 .proc_handler   = &proc_dointvec_minmax,
1530                 .strategy       = &sysctl_intvec,
1531                 .extra1         = &zero,
1532                 .extra2         = &two,
1533         },
1534 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1535         {
1536                 .ctl_name       = CTL_UNNUMBERED,
1537                 .procname       = "binfmt_misc",
1538                 .mode           = 0555,
1539                 .child          = binfmt_misc_table,
1540         },
1541 #endif
1542 /*
1543  * NOTE: do not add new entries to this table unless you have read
1544  * Documentation/sysctl/ctl_unnumbered.txt
1545  */
1546         { .ctl_name = 0 }
1547 };
1548
1549 static struct ctl_table debug_table[] = {
1550 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1551         {
1552                 .ctl_name       = CTL_UNNUMBERED,
1553                 .procname       = "exception-trace",
1554                 .data           = &show_unhandled_signals,
1555                 .maxlen         = sizeof(int),
1556                 .mode           = 0644,
1557                 .proc_handler   = proc_dointvec
1558         },
1559 #endif
1560         { .ctl_name = 0 }
1561 };
1562
1563 static struct ctl_table dev_table[] = {
1564         { .ctl_name = 0 }
1565 };
1566
1567 static DEFINE_SPINLOCK(sysctl_lock);
1568
1569 /* called under sysctl_lock */
1570 static int use_table(struct ctl_table_header *p)
1571 {
1572         if (unlikely(p->unregistering))
1573                 return 0;
1574         p->used++;
1575         return 1;
1576 }
1577
1578 /* called under sysctl_lock */
1579 static void unuse_table(struct ctl_table_header *p)
1580 {
1581         if (!--p->used)
1582                 if (unlikely(p->unregistering))
1583                         complete(p->unregistering);
1584 }
1585
1586 /* called under sysctl_lock, will reacquire if has to wait */
1587 static void start_unregistering(struct ctl_table_header *p)
1588 {
1589         /*
1590          * if p->used is 0, nobody will ever touch that entry again;
1591          * we'll eliminate all paths to it before dropping sysctl_lock
1592          */
1593         if (unlikely(p->used)) {
1594                 struct completion wait;
1595                 init_completion(&wait);
1596                 p->unregistering = &wait;
1597                 spin_unlock(&sysctl_lock);
1598                 wait_for_completion(&wait);
1599                 spin_lock(&sysctl_lock);
1600         } else {
1601                 /* anything non-NULL; we'll never dereference it */
1602                 p->unregistering = ERR_PTR(-EINVAL);
1603         }
1604         /*
1605          * do not remove from the list until nobody holds it; walking the
1606          * list in do_sysctl() relies on that.
1607          */
1608         list_del_init(&p->ctl_entry);
1609 }
1610
1611 void sysctl_head_get(struct ctl_table_header *head)
1612 {
1613         spin_lock(&sysctl_lock);
1614         head->count++;
1615         spin_unlock(&sysctl_lock);
1616 }
1617
1618 void sysctl_head_put(struct ctl_table_header *head)
1619 {
1620         spin_lock(&sysctl_lock);
1621         if (!--head->count)
1622                 kfree(head);
1623         spin_unlock(&sysctl_lock);
1624 }
1625
1626 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1627 {
1628         if (!head)
1629                 BUG();
1630         spin_lock(&sysctl_lock);
1631         if (!use_table(head))
1632                 head = ERR_PTR(-ENOENT);
1633         spin_unlock(&sysctl_lock);
1634         return head;
1635 }
1636
1637 void sysctl_head_finish(struct ctl_table_header *head)
1638 {
1639         if (!head)
1640                 return;
1641         spin_lock(&sysctl_lock);
1642         unuse_table(head);
1643         spin_unlock(&sysctl_lock);
1644 }
1645
1646 static struct ctl_table_set *
1647 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1648 {
1649         struct ctl_table_set *set = &root->default_set;
1650         if (root->lookup)
1651                 set = root->lookup(root, namespaces);
1652         return set;
1653 }
1654
1655 static struct list_head *
1656 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1657 {
1658         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1659         return &set->list;
1660 }
1661
1662 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1663                                             struct ctl_table_header *prev)
1664 {
1665         struct ctl_table_root *root;
1666         struct list_head *header_list;
1667         struct ctl_table_header *head;
1668         struct list_head *tmp;
1669
1670         spin_lock(&sysctl_lock);
1671         if (prev) {
1672                 head = prev;
1673                 tmp = &prev->ctl_entry;
1674                 unuse_table(prev);
1675                 goto next;
1676         }
1677         tmp = &root_table_header.ctl_entry;
1678         for (;;) {
1679                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1680
1681                 if (!use_table(head))
1682                         goto next;
1683                 spin_unlock(&sysctl_lock);
1684                 return head;
1685         next:
1686                 root = head->root;
1687                 tmp = tmp->next;
1688                 header_list = lookup_header_list(root, namespaces);
1689                 if (tmp != header_list)
1690                         continue;
1691
1692                 do {
1693                         root = list_entry(root->root_list.next,
1694                                         struct ctl_table_root, root_list);
1695                         if (root == &sysctl_table_root)
1696                                 goto out;
1697                         header_list = lookup_header_list(root, namespaces);
1698                 } while (list_empty(header_list));
1699                 tmp = header_list->next;
1700         }
1701 out:
1702         spin_unlock(&sysctl_lock);
1703         return NULL;
1704 }
1705
1706 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1707 {
1708         return __sysctl_head_next(current->nsproxy, prev);
1709 }
1710
1711 void register_sysctl_root(struct ctl_table_root *root)
1712 {
1713         spin_lock(&sysctl_lock);
1714         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1715         spin_unlock(&sysctl_lock);
1716 }
1717
1718 #ifdef CONFIG_SYSCTL_SYSCALL
1719 /* Perform the actual read/write of a sysctl table entry. */
1720 static int do_sysctl_strategy(struct ctl_table_root *root,
1721                         struct ctl_table *table,
1722                         void __user *oldval, size_t __user *oldlenp,
1723                         void __user *newval, size_t newlen)
1724 {
1725         int op = 0, rc;
1726
1727         if (oldval)
1728                 op |= MAY_READ;
1729         if (newval)
1730                 op |= MAY_WRITE;
1731         if (sysctl_perm(root, table, op))
1732                 return -EPERM;
1733
1734         if (table->strategy) {
1735                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1736                 if (rc < 0)
1737                         return rc;
1738                 if (rc > 0)
1739                         return 0;
1740         }
1741
1742         /* If there is no strategy routine, or if the strategy returns
1743          * zero, proceed with automatic r/w */
1744         if (table->data && table->maxlen) {
1745                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1746                 if (rc < 0)
1747                         return rc;
1748         }
1749         return 0;
1750 }
1751
1752 static int parse_table(int __user *name, int nlen,
1753                        void __user *oldval, size_t __user *oldlenp,
1754                        void __user *newval, size_t newlen,
1755                        struct ctl_table_root *root,
1756                        struct ctl_table *table)
1757 {
1758         int n;
1759 repeat:
1760         if (!nlen)
1761                 return -ENOTDIR;
1762         if (get_user(n, name))
1763                 return -EFAULT;
1764         for ( ; table->ctl_name || table->procname; table++) {
1765                 if (!table->ctl_name)
1766                         continue;
1767                 if (n == table->ctl_name) {
1768                         int error;
1769                         if (table->child) {
1770                                 if (sysctl_perm(root, table, MAY_EXEC))
1771                                         return -EPERM;
1772                                 name++;
1773                                 nlen--;
1774                                 table = table->child;
1775                                 goto repeat;
1776                         }
1777                         error = do_sysctl_strategy(root, table,
1778                                                    oldval, oldlenp,
1779                                                    newval, newlen);
1780                         return error;
1781                 }
1782         }
1783         return -ENOTDIR;
1784 }
1785
1786 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1787                void __user *newval, size_t newlen)
1788 {
1789         struct ctl_table_header *head;
1790         int error = -ENOTDIR;
1791
1792         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1793                 return -ENOTDIR;
1794         if (oldval) {
1795                 int old_len;
1796                 if (!oldlenp || get_user(old_len, oldlenp))
1797                         return -EFAULT;
1798         }
1799
1800         for (head = sysctl_head_next(NULL); head;
1801                         head = sysctl_head_next(head)) {
1802                 error = parse_table(name, nlen, oldval, oldlenp,
1803                                         newval, newlen,
1804                                         head->root, head->ctl_table);
1805                 if (error != -ENOTDIR) {
1806                         sysctl_head_finish(head);
1807                         break;
1808                 }
1809         }
1810         return error;
1811 }
1812
1813 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1814 {
1815         struct __sysctl_args tmp;
1816         int error;
1817
1818         if (copy_from_user(&tmp, args, sizeof(tmp)))
1819                 return -EFAULT;
1820
1821         error = deprecated_sysctl_warning(&tmp);
1822         if (error)
1823                 goto out;
1824
1825         lock_kernel();
1826         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1827                           tmp.newval, tmp.newlen);
1828         unlock_kernel();
1829 out:
1830         return error;
1831 }
1832 #endif /* CONFIG_SYSCTL_SYSCALL */
1833
1834 /*
1835  * sysctl_perm does NOT grant the superuser all rights automatically, because
1836  * some sysctl variables are readonly even to root.
1837  */
1838
1839 static int test_perm(int mode, int op)
1840 {
1841         if (!current_euid())
1842                 mode >>= 6;
1843         else if (in_egroup_p(0))
1844                 mode >>= 3;
1845         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1846                 return 0;
1847         return -EACCES;
1848 }
1849
1850 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1851 {
1852         int error;
1853         int mode;
1854
1855         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1856         if (error)
1857                 return error;
1858
1859         if (root->permissions)
1860                 mode = root->permissions(root, current->nsproxy, table);
1861         else
1862                 mode = table->mode;
1863
1864         return test_perm(mode, op);
1865 }
1866
1867 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1868 {
1869         for (; table->ctl_name || table->procname; table++) {
1870                 table->parent = parent;
1871                 if (table->child)
1872                         sysctl_set_parent(table, table->child);
1873         }
1874 }
1875
1876 static __init int sysctl_init(void)
1877 {
1878         sysctl_set_parent(NULL, root_table);
1879 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1880         {
1881                 int err;
1882                 err = sysctl_check_table(current->nsproxy, root_table);
1883         }
1884 #endif
1885         return 0;
1886 }
1887
1888 core_initcall(sysctl_init);
1889
1890 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1891                                       struct ctl_table *table)
1892 {
1893         struct ctl_table *p;
1894         const char *s = branch->procname;
1895
1896         /* branch should have named subdirectory as its first element */
1897         if (!s || !branch->child)
1898                 return NULL;
1899
1900         /* ... and nothing else */
1901         if (branch[1].procname || branch[1].ctl_name)
1902                 return NULL;
1903
1904         /* table should contain subdirectory with the same name */
1905         for (p = table; p->procname || p->ctl_name; p++) {
1906                 if (!p->child)
1907                         continue;
1908                 if (p->procname && strcmp(p->procname, s) == 0)
1909                         return p;
1910         }
1911         return NULL;
1912 }
1913
1914 /* see if attaching q to p would be an improvement */
1915 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1916 {
1917         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1918         struct ctl_table *next;
1919         int is_better = 0;
1920         int not_in_parent = !p->attached_by;
1921
1922         while ((next = is_branch_in(by, to)) != NULL) {
1923                 if (by == q->attached_by)
1924                         is_better = 1;
1925                 if (to == p->attached_by)
1926                         not_in_parent = 1;
1927                 by = by->child;
1928                 to = next->child;
1929         }
1930
1931         if (is_better && not_in_parent) {
1932                 q->attached_by = by;
1933                 q->attached_to = to;
1934                 q->parent = p;
1935         }
1936 }
1937
1938 /**
1939  * __register_sysctl_paths - register a sysctl hierarchy
1940  * @root: List of sysctl headers to register on
1941  * @namespaces: Data to compute which lists of sysctl entries are visible
1942  * @path: The path to the directory the sysctl table is in.
1943  * @table: the top-level table structure
1944  *
1945  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1946  * array. A completely 0 filled entry terminates the table.
1947  *
1948  * The members of the &struct ctl_table structure are used as follows:
1949  *
1950  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1951  *            must be unique within that level of sysctl
1952  *
1953  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1954  *            enter a sysctl file
1955  *
1956  * data - a pointer to data for use by proc_handler
1957  *
1958  * maxlen - the maximum size in bytes of the data
1959  *
1960  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1961  *
1962  * child - a pointer to the child sysctl table if this entry is a directory, or
1963  *         %NULL.
1964  *
1965  * proc_handler - the text handler routine (described below)
1966  *
1967  * strategy - the strategy routine (described below)
1968  *
1969  * de - for internal use by the sysctl routines
1970  *
1971  * extra1, extra2 - extra pointers usable by the proc handler routines
1972  *
1973  * Leaf nodes in the sysctl tree will be represented by a single file
1974  * under /proc; non-leaf nodes will be represented by directories.
1975  *
1976  * sysctl(2) can automatically manage read and write requests through
1977  * the sysctl table.  The data and maxlen fields of the ctl_table
1978  * struct enable minimal validation of the values being written to be
1979  * performed, and the mode field allows minimal authentication.
1980  *
1981  * More sophisticated management can be enabled by the provision of a
1982  * strategy routine with the table entry.  This will be called before
1983  * any automatic read or write of the data is performed.
1984  *
1985  * The strategy routine may return
1986  *
1987  * < 0 - Error occurred (error is passed to user process)
1988  *
1989  * 0   - OK - proceed with automatic read or write.
1990  *
1991  * > 0 - OK - read or write has been done by the strategy routine, so
1992  *       return immediately.
1993  *
1994  * There must be a proc_handler routine for any terminal nodes
1995  * mirrored under /proc/sys (non-terminals are handled by a built-in
1996  * directory handler).  Several default handlers are available to
1997  * cover common cases -
1998  *
1999  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
2000  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
2001  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
2002  *
2003  * It is the handler's job to read the input buffer from user memory
2004  * and process it. The handler should return 0 on success.
2005  *
2006  * This routine returns %NULL on a failure to register, and a pointer
2007  * to the table header on success.
2008  */
2009 struct ctl_table_header *__register_sysctl_paths(
2010         struct ctl_table_root *root,
2011         struct nsproxy *namespaces,
2012         const struct ctl_path *path, struct ctl_table *table)
2013 {
2014         struct ctl_table_header *header;
2015         struct ctl_table *new, **prevp;
2016         unsigned int n, npath;
2017         struct ctl_table_set *set;
2018
2019         /* Count the path components */
2020         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2021                 ;
2022
2023         /*
2024          * For each path component, allocate a 2-element ctl_table array.
2025          * The first array element will be filled with the sysctl entry
2026          * for this, the second will be the sentinel (ctl_name == 0).
2027          *
2028          * We allocate everything in one go so that we don't have to
2029          * worry about freeing additional memory in unregister_sysctl_table.
2030          */
2031         header = kzalloc(sizeof(struct ctl_table_header) +
2032                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2033         if (!header)
2034                 return NULL;
2035
2036         new = (struct ctl_table *) (header + 1);
2037
2038         /* Now connect the dots */
2039         prevp = &header->ctl_table;
2040         for (n = 0; n < npath; ++n, ++path) {
2041                 /* Copy the procname */
2042                 new->procname = path->procname;
2043                 new->ctl_name = path->ctl_name;
2044                 new->mode     = 0555;
2045
2046                 *prevp = new;
2047                 prevp = &new->child;
2048
2049                 new += 2;
2050         }
2051         *prevp = table;
2052         header->ctl_table_arg = table;
2053
2054         INIT_LIST_HEAD(&header->ctl_entry);
2055         header->used = 0;
2056         header->unregistering = NULL;
2057         header->root = root;
2058         sysctl_set_parent(NULL, header->ctl_table);
2059         header->count = 1;
2060 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2061         if (sysctl_check_table(namespaces, header->ctl_table)) {
2062                 kfree(header);
2063                 return NULL;
2064         }
2065 #endif
2066         spin_lock(&sysctl_lock);
2067         header->set = lookup_header_set(root, namespaces);
2068         header->attached_by = header->ctl_table;
2069         header->attached_to = root_table;
2070         header->parent = &root_table_header;
2071         for (set = header->set; set; set = set->parent) {
2072                 struct ctl_table_header *p;
2073                 list_for_each_entry(p, &set->list, ctl_entry) {
2074                         if (p->unregistering)
2075                                 continue;
2076                         try_attach(p, header);
2077                 }
2078         }
2079         header->parent->count++;
2080         list_add_tail(&header->ctl_entry, &header->set->list);
2081         spin_unlock(&sysctl_lock);
2082
2083         return header;
2084 }
2085
2086 /**
2087  * register_sysctl_table_path - register a sysctl table hierarchy
2088  * @path: The path to the directory the sysctl table is in.
2089  * @table: the top-level table structure
2090  *
2091  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2092  * array. A completely 0 filled entry terminates the table.
2093  *
2094  * See __register_sysctl_paths for more details.
2095  */
2096 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2097                                                 struct ctl_table *table)
2098 {
2099         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2100                                         path, table);
2101 }
2102
2103 /**
2104  * register_sysctl_table - register a sysctl table hierarchy
2105  * @table: the top-level table structure
2106  *
2107  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2108  * array. A completely 0 filled entry terminates the table.
2109  *
2110  * See register_sysctl_paths for more details.
2111  */
2112 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2113 {
2114         static const struct ctl_path null_path[] = { {} };
2115
2116         return register_sysctl_paths(null_path, table);
2117 }
2118
2119 /**
2120  * unregister_sysctl_table - unregister a sysctl table hierarchy
2121  * @header: the header returned from register_sysctl_table
2122  *
2123  * Unregisters the sysctl table and all children. proc entries may not
2124  * actually be removed until they are no longer used by anyone.
2125  */
2126 void unregister_sysctl_table(struct ctl_table_header * header)
2127 {
2128         might_sleep();
2129
2130         if (header == NULL)
2131                 return;
2132
2133         spin_lock(&sysctl_lock);
2134         start_unregistering(header);
2135         if (!--header->parent->count) {
2136                 WARN_ON(1);
2137                 kfree(header->parent);
2138         }
2139         if (!--header->count)
2140                 kfree(header);
2141         spin_unlock(&sysctl_lock);
2142 }
2143
2144 int sysctl_is_seen(struct ctl_table_header *p)
2145 {
2146         struct ctl_table_set *set = p->set;
2147         int res;
2148         spin_lock(&sysctl_lock);
2149         if (p->unregistering)
2150                 res = 0;
2151         else if (!set->is_seen)
2152                 res = 1;
2153         else
2154                 res = set->is_seen(set);
2155         spin_unlock(&sysctl_lock);
2156         return res;
2157 }
2158
2159 void setup_sysctl_set(struct ctl_table_set *p,
2160         struct ctl_table_set *parent,
2161         int (*is_seen)(struct ctl_table_set *))
2162 {
2163         INIT_LIST_HEAD(&p->list);
2164         p->parent = parent ? parent : &sysctl_table_root.default_set;
2165         p->is_seen = is_seen;
2166 }
2167
2168 #else /* !CONFIG_SYSCTL */
2169 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2170 {
2171         return NULL;
2172 }
2173
2174 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2175                                                     struct ctl_table *table)
2176 {
2177         return NULL;
2178 }
2179
2180 void unregister_sysctl_table(struct ctl_table_header * table)
2181 {
2182 }
2183
2184 void setup_sysctl_set(struct ctl_table_set *p,
2185         struct ctl_table_set *parent,
2186         int (*is_seen)(struct ctl_table_set *))
2187 {
2188 }
2189
2190 void sysctl_head_put(struct ctl_table_header *head)
2191 {
2192 }
2193
2194 #endif /* CONFIG_SYSCTL */
2195
2196 /*
2197  * /proc/sys support
2198  */
2199
2200 #ifdef CONFIG_PROC_SYSCTL
2201
2202 static int _proc_do_string(void* data, int maxlen, int write,
2203                            struct file *filp, void __user *buffer,
2204                            size_t *lenp, loff_t *ppos)
2205 {
2206         size_t len;
2207         char __user *p;
2208         char c;
2209
2210         if (!data || !maxlen || !*lenp) {
2211                 *lenp = 0;
2212                 return 0;
2213         }
2214
2215         if (write) {
2216                 len = 0;
2217                 p = buffer;
2218                 while (len < *lenp) {
2219                         if (get_user(c, p++))
2220                                 return -EFAULT;
2221                         if (c == 0 || c == '\n')
2222                                 break;
2223                         len++;
2224                 }
2225                 if (len >= maxlen)
2226                         len = maxlen-1;
2227                 if(copy_from_user(data, buffer, len))
2228                         return -EFAULT;
2229                 ((char *) data)[len] = 0;
2230                 *ppos += *lenp;
2231         } else {
2232                 len = strlen(data);
2233                 if (len > maxlen)
2234                         len = maxlen;
2235
2236                 if (*ppos > len) {
2237                         *lenp = 0;
2238                         return 0;
2239                 }
2240
2241                 data += *ppos;
2242                 len  -= *ppos;
2243
2244                 if (len > *lenp)
2245                         len = *lenp;
2246                 if (len)
2247                         if(copy_to_user(buffer, data, len))
2248                                 return -EFAULT;
2249                 if (len < *lenp) {
2250                         if(put_user('\n', ((char __user *) buffer) + len))
2251                                 return -EFAULT;
2252                         len++;
2253                 }
2254                 *lenp = len;
2255                 *ppos += len;
2256         }
2257         return 0;
2258 }
2259
2260 /**
2261  * proc_dostring - read a string sysctl
2262  * @table: the sysctl table
2263  * @write: %TRUE if this is a write to the sysctl file
2264  * @filp: the file structure
2265  * @buffer: the user buffer
2266  * @lenp: the size of the user buffer
2267  * @ppos: file position
2268  *
2269  * Reads/writes a string from/to the user buffer. If the kernel
2270  * buffer provided is not large enough to hold the string, the
2271  * string is truncated. The copied string is %NULL-terminated.
2272  * If the string is being read by the user process, it is copied
2273  * and a newline '\n' is added. It is truncated if the buffer is
2274  * not large enough.
2275  *
2276  * Returns 0 on success.
2277  */
2278 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2279                   void __user *buffer, size_t *lenp, loff_t *ppos)
2280 {
2281         return _proc_do_string(table->data, table->maxlen, write, filp,
2282                                buffer, lenp, ppos);
2283 }
2284
2285
2286 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2287                                  int *valp,
2288                                  int write, void *data)
2289 {
2290         if (write) {
2291                 *valp = *negp ? -*lvalp : *lvalp;
2292         } else {
2293                 int val = *valp;
2294                 if (val < 0) {
2295                         *negp = -1;
2296                         *lvalp = (unsigned long)-val;
2297                 } else {
2298                         *negp = 0;
2299                         *lvalp = (unsigned long)val;
2300                 }
2301         }
2302         return 0;
2303 }
2304
2305 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2306                   int write, struct file *filp, void __user *buffer,
2307                   size_t *lenp, loff_t *ppos,
2308                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2309                               int write, void *data),
2310                   void *data)
2311 {
2312 #define TMPBUFLEN 21
2313         int *i, vleft, first = 1, neg;
2314         unsigned long lval;
2315         size_t left, len;
2316
2317         char buf[TMPBUFLEN], *p;
2318         char __user *s = buffer;
2319
2320         if (!tbl_data || !table->maxlen || !*lenp ||
2321             (*ppos && !write)) {
2322                 *lenp = 0;
2323                 return 0;
2324         }
2325
2326         i = (int *) tbl_data;
2327         vleft = table->maxlen / sizeof(*i);
2328         left = *lenp;
2329
2330         if (!conv)
2331                 conv = do_proc_dointvec_conv;
2332
2333         for (; left && vleft--; i++, first=0) {
2334                 if (write) {
2335                         while (left) {
2336                                 char c;
2337                                 if (get_user(c, s))
2338                                         return -EFAULT;
2339                                 if (!isspace(c))
2340                                         break;
2341                                 left--;
2342                                 s++;
2343                         }
2344                         if (!left)
2345                                 break;
2346                         neg = 0;
2347                         len = left;
2348                         if (len > sizeof(buf) - 1)
2349                                 len = sizeof(buf) - 1;
2350                         if (copy_from_user(buf, s, len))
2351                                 return -EFAULT;
2352                         buf[len] = 0;
2353                         p = buf;
2354                         if (*p == '-' && left > 1) {
2355                                 neg = 1;
2356                                 p++;
2357                         }
2358                         if (*p < '0' || *p > '9')
2359                                 break;
2360
2361                         lval = simple_strtoul(p, &p, 0);
2362
2363                         len = p-buf;
2364                         if ((len < left) && *p && !isspace(*p))
2365                                 break;
2366                         s += len;
2367                         left -= len;
2368
2369                         if (conv(&neg, &lval, i, 1, data))
2370                                 break;
2371                 } else {
2372                         p = buf;
2373                         if (!first)
2374                                 *p++ = '\t';
2375
2376                         if (conv(&neg, &lval, i, 0, data))
2377                                 break;
2378
2379                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2380                         len = strlen(buf);
2381                         if (len > left)
2382                                 len = left;
2383                         if(copy_to_user(s, buf, len))
2384                                 return -EFAULT;
2385                         left -= len;
2386                         s += len;
2387                 }
2388         }
2389
2390         if (!write && !first && left) {
2391                 if(put_user('\n', s))
2392                         return -EFAULT;
2393                 left--, s++;
2394         }
2395         if (write) {
2396                 while (left) {
2397                         char c;
2398                         if (get_user(c, s++))
2399                                 return -EFAULT;
2400                         if (!isspace(c))
2401                                 break;
2402                         left--;
2403                 }
2404         }
2405         if (write && first)
2406                 return -EINVAL;
2407         *lenp -= left;
2408         *ppos += *lenp;
2409         return 0;
2410 #undef TMPBUFLEN
2411 }
2412
2413 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2414                   void __user *buffer, size_t *lenp, loff_t *ppos,
2415                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2416                               int write, void *data),
2417                   void *data)
2418 {
2419         return __do_proc_dointvec(table->data, table, write, filp,
2420                         buffer, lenp, ppos, conv, data);
2421 }
2422
2423 /**
2424  * proc_dointvec - read a vector of integers
2425  * @table: the sysctl table
2426  * @write: %TRUE if this is a write to the sysctl file
2427  * @filp: the file structure
2428  * @buffer: the user buffer
2429  * @lenp: the size of the user buffer
2430  * @ppos: file position
2431  *
2432  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2433  * values from/to the user buffer, treated as an ASCII string.
2434  *
2435  * Returns 0 on success.
2436  */
2437 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2438                      void __user *buffer, size_t *lenp, loff_t *ppos)
2439 {
2440     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2441                             NULL,NULL);
2442 }
2443
2444 /*
2445  * Taint values can only be increased
2446  * This means we can safely use a temporary.
2447  */
2448 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2449                                void __user *buffer, size_t *lenp, loff_t *ppos)
2450 {
2451         struct ctl_table t;
2452         unsigned long tmptaint = get_taint();
2453         int err;
2454
2455         if (write && !capable(CAP_SYS_ADMIN))
2456                 return -EPERM;
2457
2458         t = *table;
2459         t.data = &tmptaint;
2460         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2461         if (err < 0)
2462                 return err;
2463
2464         if (write) {
2465                 /*
2466                  * Poor man's atomic or. Not worth adding a primitive
2467                  * to everyone's atomic.h for this
2468                  */
2469                 int i;
2470                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2471                         if ((tmptaint >> i) & 1)
2472                                 add_taint(i);
2473                 }
2474         }
2475
2476         return err;
2477 }
2478
2479 struct do_proc_dointvec_minmax_conv_param {
2480         int *min;
2481         int *max;
2482 };
2483
2484 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2485                                         int *valp,
2486                                         int write, void *data)
2487 {
2488         struct do_proc_dointvec_minmax_conv_param *param = data;
2489         if (write) {
2490                 int val = *negp ? -*lvalp : *lvalp;
2491                 if ((param->min && *param->min > val) ||
2492                     (param->max && *param->max < val))
2493                         return -EINVAL;
2494                 *valp = val;
2495         } else {
2496                 int val = *valp;
2497                 if (val < 0) {
2498                         *negp = -1;
2499                         *lvalp = (unsigned long)-val;
2500                 } else {
2501                         *negp = 0;
2502                         *lvalp = (unsigned long)val;
2503                 }
2504         }
2505         return 0;
2506 }
2507
2508 /**
2509  * proc_dointvec_minmax - read a vector of integers with min/max values
2510  * @table: the sysctl table
2511  * @write: %TRUE if this is a write to the sysctl file
2512  * @filp: the file structure
2513  * @buffer: the user buffer
2514  * @lenp: the size of the user buffer
2515  * @ppos: file position
2516  *
2517  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2518  * values from/to the user buffer, treated as an ASCII string.
2519  *
2520  * This routine will ensure the values are within the range specified by
2521  * table->extra1 (min) and table->extra2 (max).
2522  *
2523  * Returns 0 on success.
2524  */
2525 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2526                   void __user *buffer, size_t *lenp, loff_t *ppos)
2527 {
2528         struct do_proc_dointvec_minmax_conv_param param = {
2529                 .min = (int *) table->extra1,
2530                 .max = (int *) table->extra2,
2531         };
2532         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2533                                 do_proc_dointvec_minmax_conv, &param);
2534 }
2535
2536 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2537                                      struct file *filp,
2538                                      void __user *buffer,
2539                                      size_t *lenp, loff_t *ppos,
2540                                      unsigned long convmul,
2541                                      unsigned long convdiv)
2542 {
2543 #define TMPBUFLEN 21
2544         unsigned long *i, *min, *max, val;
2545         int vleft, first=1, neg;
2546         size_t len, left;
2547         char buf[TMPBUFLEN], *p;
2548         char __user *s = buffer;
2549
2550         if (!data || !table->maxlen || !*lenp ||
2551             (*ppos && !write)) {
2552                 *lenp = 0;
2553                 return 0;
2554         }
2555
2556         i = (unsigned long *) data;
2557         min = (unsigned long *) table->extra1;
2558         max = (unsigned long *) table->extra2;
2559         vleft = table->maxlen / sizeof(unsigned long);
2560         left = *lenp;
2561
2562         for (; left && vleft--; i++, min++, max++, first=0) {
2563                 if (write) {
2564                         while (left) {
2565                                 char c;
2566                                 if (get_user(c, s))
2567                                         return -EFAULT;
2568                                 if (!isspace(c))
2569                                         break;
2570                                 left--;
2571                                 s++;
2572                         }
2573                         if (!left)
2574                                 break;
2575                         neg = 0;
2576                         len = left;
2577                         if (len > TMPBUFLEN-1)
2578                                 len = TMPBUFLEN-1;
2579                         if (copy_from_user(buf, s, len))
2580                                 return -EFAULT;
2581                         buf[len] = 0;
2582                         p = buf;
2583                         if (*p == '-' && left > 1) {
2584                                 neg = 1;
2585                                 p++;
2586                         }
2587                         if (*p < '0' || *p > '9')
2588                                 break;
2589                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2590                         len = p-buf;
2591                         if ((len < left) && *p && !isspace(*p))
2592                                 break;
2593                         if (neg)
2594                                 val = -val;
2595                         s += len;
2596                         left -= len;
2597
2598                         if(neg)
2599                                 continue;
2600                         if ((min && val < *min) || (max && val > *max))
2601                                 continue;
2602                         *i = val;
2603                 } else {
2604                         p = buf;
2605                         if (!first)
2606                                 *p++ = '\t';
2607                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2608                         len = strlen(buf);
2609                         if (len > left)
2610                                 len = left;
2611                         if(copy_to_user(s, buf, len))
2612                                 return -EFAULT;
2613                         left -= len;
2614                         s += len;
2615                 }
2616         }
2617
2618         if (!write && !first && left) {
2619                 if(put_user('\n', s))
2620                         return -EFAULT;
2621                 left--, s++;
2622         }
2623         if (write) {
2624                 while (left) {
2625                         char c;
2626                         if (get_user(c, s++))
2627                                 return -EFAULT;
2628                         if (!isspace(c))
2629                                 break;
2630                         left--;
2631                 }
2632         }
2633         if (write && first)
2634                 return -EINVAL;
2635         *lenp -= left;
2636         *ppos += *lenp;
2637         return 0;
2638 #undef TMPBUFLEN
2639 }
2640
2641 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2642                                      struct file *filp,
2643                                      void __user *buffer,
2644                                      size_t *lenp, loff_t *ppos,
2645                                      unsigned long convmul,
2646                                      unsigned long convdiv)
2647 {
2648         return __do_proc_doulongvec_minmax(table->data, table, write,
2649                         filp, buffer, lenp, ppos, convmul, convdiv);
2650 }
2651
2652 /**
2653  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2654  * @table: the sysctl table
2655  * @write: %TRUE if this is a write to the sysctl file
2656  * @filp: the file structure
2657  * @buffer: the user buffer
2658  * @lenp: the size of the user buffer
2659  * @ppos: file position
2660  *
2661  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2662  * values from/to the user buffer, treated as an ASCII string.
2663  *
2664  * This routine will ensure the values are within the range specified by
2665  * table->extra1 (min) and table->extra2 (max).
2666  *
2667  * Returns 0 on success.
2668  */
2669 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2670                            void __user *buffer, size_t *lenp, loff_t *ppos)
2671 {
2672     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2673 }
2674
2675 /**
2676  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2677  * @table: the sysctl table
2678  * @write: %TRUE if this is a write to the sysctl file
2679  * @filp: the file structure
2680  * @buffer: the user buffer
2681  * @lenp: the size of the user buffer
2682  * @ppos: file position
2683  *
2684  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2685  * values from/to the user buffer, treated as an ASCII string. The values
2686  * are treated as milliseconds, and converted to jiffies when they are stored.
2687  *
2688  * This routine will ensure the values are within the range specified by
2689  * table->extra1 (min) and table->extra2 (max).
2690  *
2691  * Returns 0 on success.
2692  */
2693 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2694                                       struct file *filp,
2695                                       void __user *buffer,
2696                                       size_t *lenp, loff_t *ppos)
2697 {
2698     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2699                                      lenp, ppos, HZ, 1000l);
2700 }
2701
2702
2703 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2704                                          int *valp,
2705                                          int write, void *data)
2706 {
2707         if (write) {
2708                 if (*lvalp > LONG_MAX / HZ)
2709                         return 1;
2710                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2711         } else {
2712                 int val = *valp;
2713                 unsigned long lval;
2714                 if (val < 0) {
2715                         *negp = -1;
2716                         lval = (unsigned long)-val;
2717                 } else {
2718                         *negp = 0;
2719                         lval = (unsigned long)val;
2720                 }
2721                 *lvalp = lval / HZ;
2722         }
2723         return 0;
2724 }
2725
2726 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2727                                                 int *valp,
2728                                                 int write, void *data)
2729 {
2730         if (write) {
2731                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2732                         return 1;
2733                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2734         } else {
2735                 int val = *valp;
2736                 unsigned long lval;
2737                 if (val < 0) {
2738                         *negp = -1;
2739                         lval = (unsigned long)-val;
2740                 } else {
2741                         *negp = 0;
2742                         lval = (unsigned long)val;
2743                 }
2744                 *lvalp = jiffies_to_clock_t(lval);
2745         }
2746         return 0;
2747 }
2748
2749 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2750                                             int *valp,
2751                                             int write, void *data)
2752 {
2753         if (write) {
2754                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2755         } else {
2756                 int val = *valp;
2757                 unsigned long lval;
2758                 if (val < 0) {
2759                         *negp = -1;
2760                         lval = (unsigned long)-val;
2761                 } else {
2762                         *negp = 0;
2763                         lval = (unsigned long)val;
2764                 }
2765                 *lvalp = jiffies_to_msecs(lval);
2766         }
2767         return 0;
2768 }
2769
2770 /**
2771  * proc_dointvec_jiffies - read a vector of integers as seconds
2772  * @table: the sysctl table
2773  * @write: %TRUE if this is a write to the sysctl file
2774  * @filp: the file structure
2775  * @buffer: the user buffer
2776  * @lenp: the size of the user buffer
2777  * @ppos: file position
2778  *
2779  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2780  * values from/to the user buffer, treated as an ASCII string.
2781  * The values read are assumed to be in seconds, and are converted into
2782  * jiffies.
2783  *
2784  * Returns 0 on success.
2785  */
2786 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2787                           void __user *buffer, size_t *lenp, loff_t *ppos)
2788 {
2789     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2790                             do_proc_dointvec_jiffies_conv,NULL);
2791 }
2792
2793 /**
2794  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2795  * @table: the sysctl table
2796  * @write: %TRUE if this is a write to the sysctl file
2797  * @filp: the file structure
2798  * @buffer: the user buffer
2799  * @lenp: the size of the user buffer
2800  * @ppos: pointer to the file position
2801  *
2802  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2803  * values from/to the user buffer, treated as an ASCII string.
2804  * The values read are assumed to be in 1/USER_HZ seconds, and
2805  * are converted into jiffies.
2806  *
2807  * Returns 0 on success.
2808  */
2809 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2810                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2811 {
2812     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2813                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2814 }
2815
2816 /**
2817  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2818  * @table: the sysctl table
2819  * @write: %TRUE if this is a write to the sysctl file
2820  * @filp: the file structure
2821  * @buffer: the user buffer
2822  * @lenp: the size of the user buffer
2823  * @ppos: file position
2824  * @ppos: the current position in the file
2825  *
2826  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2827  * values from/to the user buffer, treated as an ASCII string.
2828  * The values read are assumed to be in 1/1000 seconds, and
2829  * are converted into jiffies.
2830  *
2831  * Returns 0 on success.
2832  */
2833 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2834                              void __user *buffer, size_t *lenp, loff_t *ppos)
2835 {
2836         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2837                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2838 }
2839
2840 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2841                            void __user *buffer, size_t *lenp, loff_t *ppos)
2842 {
2843         struct pid *new_pid;
2844         pid_t tmp;
2845         int r;
2846
2847         tmp = pid_vnr(cad_pid);
2848
2849         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2850                                lenp, ppos, NULL, NULL);
2851         if (r || !write)
2852                 return r;
2853
2854         new_pid = find_get_pid(tmp);
2855         if (!new_pid)
2856                 return -ESRCH;
2857
2858         put_pid(xchg(&cad_pid, new_pid));
2859         return 0;
2860 }
2861
2862 #else /* CONFIG_PROC_FS */
2863
2864 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2865                   void __user *buffer, size_t *lenp, loff_t *ppos)
2866 {
2867         return -ENOSYS;
2868 }
2869
2870 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2871                   void __user *buffer, size_t *lenp, loff_t *ppos)
2872 {
2873         return -ENOSYS;
2874 }
2875
2876 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2877                     void __user *buffer, size_t *lenp, loff_t *ppos)
2878 {
2879         return -ENOSYS;
2880 }
2881
2882 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2883                     void __user *buffer, size_t *lenp, loff_t *ppos)
2884 {
2885         return -ENOSYS;
2886 }
2887
2888 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2889                     void __user *buffer, size_t *lenp, loff_t *ppos)
2890 {
2891         return -ENOSYS;
2892 }
2893
2894 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2895                              void __user *buffer, size_t *lenp, loff_t *ppos)
2896 {
2897         return -ENOSYS;
2898 }
2899
2900 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2901                     void __user *buffer, size_t *lenp, loff_t *ppos)
2902 {
2903         return -ENOSYS;
2904 }
2905
2906 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2907                                       struct file *filp,
2908                                       void __user *buffer,
2909                                       size_t *lenp, loff_t *ppos)
2910 {
2911     return -ENOSYS;
2912 }
2913
2914
2915 #endif /* CONFIG_PROC_FS */
2916
2917
2918 #ifdef CONFIG_SYSCTL_SYSCALL
2919 /*
2920  * General sysctl support routines
2921  */
2922
2923 /* The generic sysctl data routine (used if no strategy routine supplied) */
2924 int sysctl_data(struct ctl_table *table,
2925                 void __user *oldval, size_t __user *oldlenp,
2926                 void __user *newval, size_t newlen)
2927 {
2928         size_t len;
2929
2930         /* Get out of I don't have a variable */
2931         if (!table->data || !table->maxlen)
2932                 return -ENOTDIR;
2933
2934         if (oldval && oldlenp) {
2935                 if (get_user(len, oldlenp))
2936                         return -EFAULT;
2937                 if (len) {
2938                         if (len > table->maxlen)
2939                                 len = table->maxlen;
2940                         if (copy_to_user(oldval, table->data, len))
2941                                 return -EFAULT;
2942                         if (put_user(len, oldlenp))
2943                                 return -EFAULT;
2944                 }
2945         }
2946
2947         if (newval && newlen) {
2948                 if (newlen > table->maxlen)
2949                         newlen = table->maxlen;
2950
2951                 if (copy_from_user(table->data, newval, newlen))
2952                         return -EFAULT;
2953         }
2954         return 1;
2955 }
2956
2957 /* The generic string strategy routine: */
2958 int sysctl_string(struct ctl_table *table,
2959                   void __user *oldval, size_t __user *oldlenp,
2960                   void __user *newval, size_t newlen)
2961 {
2962         if (!table->data || !table->maxlen)
2963                 return -ENOTDIR;
2964
2965         if (oldval && oldlenp) {
2966                 size_t bufsize;
2967                 if (get_user(bufsize, oldlenp))
2968                         return -EFAULT;
2969                 if (bufsize) {
2970                         size_t len = strlen(table->data), copied;
2971
2972                         /* This shouldn't trigger for a well-formed sysctl */
2973                         if (len > table->maxlen)
2974                                 len = table->maxlen;
2975
2976                         /* Copy up to a max of bufsize-1 bytes of the string */
2977                         copied = (len >= bufsize) ? bufsize - 1 : len;
2978
2979                         if (copy_to_user(oldval, table->data, copied) ||
2980                             put_user(0, (char __user *)(oldval + copied)))
2981                                 return -EFAULT;
2982                         if (put_user(len, oldlenp))
2983                                 return -EFAULT;
2984                 }
2985         }
2986         if (newval && newlen) {
2987                 size_t len = newlen;
2988                 if (len > table->maxlen)
2989                         len = table->maxlen;
2990                 if(copy_from_user(table->data, newval, len))
2991                         return -EFAULT;
2992                 if (len == table->maxlen)
2993                         len--;
2994                 ((char *) table->data)[len] = 0;
2995         }
2996         return 1;
2997 }
2998
2999 /*
3000  * This function makes sure that all of the integers in the vector
3001  * are between the minimum and maximum values given in the arrays
3002  * table->extra1 and table->extra2, respectively.
3003  */
3004 int sysctl_intvec(struct ctl_table *table,
3005                 void __user *oldval, size_t __user *oldlenp,
3006                 void __user *newval, size_t newlen)
3007 {
3008
3009         if (newval && newlen) {
3010                 int __user *vec = (int __user *) newval;
3011                 int *min = (int *) table->extra1;
3012                 int *max = (int *) table->extra2;
3013                 size_t length;
3014                 int i;
3015
3016                 if (newlen % sizeof(int) != 0)
3017                         return -EINVAL;
3018
3019                 if (!table->extra1 && !table->extra2)
3020                         return 0;
3021
3022                 if (newlen > table->maxlen)
3023                         newlen = table->maxlen;
3024                 length = newlen / sizeof(int);
3025
3026                 for (i = 0; i < length; i++) {
3027                         int value;
3028                         if (get_user(value, vec + i))
3029                                 return -EFAULT;
3030                         if (min && value < min[i])
3031                                 return -EINVAL;
3032                         if (max && value > max[i])
3033                                 return -EINVAL;
3034                 }
3035         }
3036         return 0;
3037 }
3038
3039 /* Strategy function to convert jiffies to seconds */
3040 int sysctl_jiffies(struct ctl_table *table,
3041                 void __user *oldval, size_t __user *oldlenp,
3042                 void __user *newval, size_t newlen)
3043 {
3044         if (oldval && oldlenp) {
3045                 size_t olen;
3046
3047                 if (get_user(olen, oldlenp))
3048                         return -EFAULT;
3049                 if (olen) {
3050                         int val;
3051
3052                         if (olen < sizeof(int))
3053                                 return -EINVAL;
3054
3055                         val = *(int *)(table->data) / HZ;
3056                         if (put_user(val, (int __user *)oldval))
3057                                 return -EFAULT;
3058                         if (put_user(sizeof(int), oldlenp))
3059                                 return -EFAULT;
3060                 }
3061         }
3062         if (newval && newlen) {
3063                 int new;
3064                 if (newlen != sizeof(int))
3065                         return -EINVAL;
3066                 if (get_user(new, (int __user *)newval))
3067                         return -EFAULT;
3068                 *(int *)(table->data) = new*HZ;
3069         }
3070         return 1;
3071 }
3072
3073 /* Strategy function to convert jiffies to seconds */
3074 int sysctl_ms_jiffies(struct ctl_table *table,
3075                 void __user *oldval, size_t __user *oldlenp,
3076                 void __user *newval, size_t newlen)
3077 {
3078         if (oldval && oldlenp) {
3079                 size_t olen;
3080
3081                 if (get_user(olen, oldlenp))
3082                         return -EFAULT;
3083                 if (olen) {
3084                         int val;
3085
3086                         if (olen < sizeof(int))
3087                                 return -EINVAL;
3088
3089                         val = jiffies_to_msecs(*(int *)(table->data));
3090                         if (put_user(val, (int __user *)oldval))
3091                                 return -EFAULT;
3092                         if (put_user(sizeof(int), oldlenp))
3093                                 return -EFAULT;
3094                 }
3095         }
3096         if (newval && newlen) {
3097                 int new;
3098                 if (newlen != sizeof(int))
3099                         return -EINVAL;
3100                 if (get_user(new, (int __user *)newval))
3101                         return -EFAULT;
3102                 *(int *)(table->data) = msecs_to_jiffies(new);
3103         }
3104         return 1;
3105 }
3106
3107
3108
3109 #else /* CONFIG_SYSCTL_SYSCALL */
3110
3111
3112 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3113 {
3114         struct __sysctl_args tmp;
3115         int error;
3116
3117         if (copy_from_user(&tmp, args, sizeof(tmp)))
3118                 return -EFAULT;
3119
3120         error = deprecated_sysctl_warning(&tmp);
3121
3122         /* If no error reading the parameters then just -ENOSYS ... */
3123         if (!error)
3124                 error = -ENOSYS;
3125
3126         return error;
3127 }
3128
3129 int sysctl_data(struct ctl_table *table,
3130                   void __user *oldval, size_t __user *oldlenp,
3131                   void __user *newval, size_t newlen)
3132 {
3133         return -ENOSYS;
3134 }
3135
3136 int sysctl_string(struct ctl_table *table,
3137                   void __user *oldval, size_t __user *oldlenp,
3138                   void __user *newval, size_t newlen)
3139 {
3140         return -ENOSYS;
3141 }
3142
3143 int sysctl_intvec(struct ctl_table *table,
3144                 void __user *oldval, size_t __user *oldlenp,
3145                 void __user *newval, size_t newlen)
3146 {
3147         return -ENOSYS;
3148 }
3149
3150 int sysctl_jiffies(struct ctl_table *table,
3151                 void __user *oldval, size_t __user *oldlenp,
3152                 void __user *newval, size_t newlen)
3153 {
3154         return -ENOSYS;
3155 }
3156
3157 int sysctl_ms_jiffies(struct ctl_table *table,
3158                 void __user *oldval, size_t __user *oldlenp,
3159                 void __user *newval, size_t newlen)
3160 {
3161         return -ENOSYS;
3162 }
3163
3164 #endif /* CONFIG_SYSCTL_SYSCALL */
3165
3166 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3167 {
3168         static int msg_count;
3169         int name[CTL_MAXNAME];
3170         int i;
3171
3172         /* Check args->nlen. */
3173         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3174                 return -ENOTDIR;
3175
3176         /* Read in the sysctl name for better debug message logging */
3177         for (i = 0; i < args->nlen; i++)
3178                 if (get_user(name[i], args->name + i))
3179                         return -EFAULT;
3180
3181         /* Ignore accesses to kernel.version */
3182         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3183                 return 0;
3184
3185         if (msg_count < 5) {
3186                 msg_count++;
3187                 printk(KERN_INFO
3188                         "warning: process `%s' used the deprecated sysctl "
3189                         "system call with ", current->comm);
3190                 for (i = 0; i < args->nlen; i++)
3191                         printk("%d.", name[i]);
3192                 printk("\n");
3193         }
3194         return 0;
3195 }
3196
3197 /*
3198  * No sense putting this after each symbol definition, twice,
3199  * exception granted :-)
3200  */
3201 EXPORT_SYMBOL(proc_dointvec);
3202 EXPORT_SYMBOL(proc_dointvec_jiffies);
3203 EXPORT_SYMBOL(proc_dointvec_minmax);
3204 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3205 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3206 EXPORT_SYMBOL(proc_dostring);
3207 EXPORT_SYMBOL(proc_doulongvec_minmax);
3208 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3209 EXPORT_SYMBOL(register_sysctl_table);
3210 EXPORT_SYMBOL(register_sysctl_paths);
3211 EXPORT_SYMBOL(sysctl_intvec);
3212 EXPORT_SYMBOL(sysctl_jiffies);
3213 EXPORT_SYMBOL(sysctl_ms_jiffies);
3214 EXPORT_SYMBOL(sysctl_string);
3215 EXPORT_SYMBOL(sysctl_data);
3216 EXPORT_SYMBOL(unregister_sysctl_table);