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   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/kmemcheck.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/ratelimit.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_event.h>
  54
  55 #include <asm/uaccess.h>
  56 #include <asm/processor.h>
  57
  58 #ifdef CONFIG_X86
  59 #include <asm/nmi.h>
  60 #include <asm/stacktrace.h>
  61 #include <asm/io.h>
  62 #endif
  63
  64 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  65
  66 #if defined(CONFIG_SYSCTL)
  67
  68 /* External variables not in a header file. */
  69 extern int C_A_D;
  70 extern int print_fatal_signals;
  71 extern int sysctl_overcommit_memory;
  72 extern int sysctl_overcommit_ratio;
  73 extern int sysctl_panic_on_oom;
  74 extern int sysctl_oom_kill_allocating_task;
  75 extern int sysctl_oom_dump_tasks;
  76 extern int max_threads;
  77 extern int core_uses_pid;
  78 extern int suid_dumpable;
  79 extern char core_pattern[];
  80 extern unsigned int core_pipe_limit;
  81 extern int pid_max;
  82 extern int min_free_kbytes;
  83 extern int pid_max_min, pid_max_max;
  84 extern int sysctl_drop_caches;
  85 extern int percpu_pagelist_fraction;
  86 extern int compat_log;
  87 extern int latencytop_enabled;
  88 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  89 #ifndef CONFIG_MMU
  90 extern int sysctl_nr_trim_pages;
  91 #endif
  92 #ifdef CONFIG_RCU_TORTURE_TEST
  93 extern int rcutorture_runnable;
  94 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  95 #ifdef CONFIG_BLOCK
  96 extern int blk_iopoll_enabled;
  97 #endif
  98
  99 /* Constants used for minimum and  maximum */
 100 #ifdef CONFIG_DETECT_SOFTLOCKUP
 101 static int sixty = 60;
 102 static int neg_one = -1;
 103 #endif
 104
 105 static int zero;
 106 static int __maybe_unused one = 1;
 107 static int __maybe_unused two = 2;
 108 static unsigned long one_ul = 1;
 109 static int one_hundred = 100;
 110 #ifdef CONFIG_PRINTK
 111 static int ten_thousand = 10000;
 112 #endif
 113
 114 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 115 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 116
 117 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 118 static int maxolduid = 65535;
 119 static int minolduid;
 120 static int min_percpu_pagelist_fract = 8;
 121
 122 static int ngroups_max = NGROUPS_MAX;
 123
 124 #ifdef CONFIG_MODULES
 125 extern char modprobe_path[];
 126 extern int modules_disabled;
 127 #endif
 128 #ifdef CONFIG_CHR_DEV_SG
 129 extern int sg_big_buff;
 130 #endif
 131
 132 #ifdef CONFIG_SPARC
 133 #include <asm/system.h>
 134 #endif
 135
 136 #ifdef CONFIG_SPARC64
 137 extern int sysctl_tsb_ratio;
 138 #endif
 139
 140 #ifdef __hppa__
 141 extern int pwrsw_enabled;
 142 extern int unaligned_enabled;
 143 #endif
 144
 145 #ifdef CONFIG_S390
 146 #ifdef CONFIG_MATHEMU
 147 extern int sysctl_ieee_emulation_warnings;
 148 #endif
 149 extern int sysctl_userprocess_debug;
 150 extern int spin_retry;
 151 #endif
 152
 153 #ifdef CONFIG_BSD_PROCESS_ACCT
 154 extern int acct_parm[];
 155 #endif
 156
 157 #ifdef CONFIG_IA64
 158 extern int no_unaligned_warning;
 159 extern int unaligned_dump_stack;
 160 #endif
 161
 162 extern struct ratelimit_state printk_ratelimit_state;
 163
 164 #ifdef CONFIG_RT_MUTEXES
 165 extern int max_lock_depth;
 166 #endif
 167
 168 #ifdef CONFIG_PROC_SYSCTL
 169 static int proc_do_cad_pid(struct ctl_table *table, int write,
 170                   void __user *buffer, size_t *lenp, loff_t *ppos);
 171 static int proc_taint(struct ctl_table *table, int write,
 172                                void __user *buffer, size_t *lenp, loff_t *ppos);
 173 #endif
 174
 175 static struct ctl_table root_table[];
 176 static struct ctl_table_root sysctl_table_root;
 177 static struct ctl_table_header root_table_header = {
 178         .count = 1,
 179         .ctl_table = root_table,
 180         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 181         .root = &sysctl_table_root,
 182         .set = &sysctl_table_root.default_set,
 183 };
 184 static struct ctl_table_root sysctl_table_root = {
 185         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 186         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 187 };
 188
 189 static struct ctl_table kern_table[];
 190 static struct ctl_table vm_table[];
 191 static struct ctl_table fs_table[];
 192 static struct ctl_table debug_table[];
 193 static struct ctl_table dev_table[];
 194 extern struct ctl_table random_table[];
 195 #ifdef CONFIG_INOTIFY_USER
 196 extern struct ctl_table inotify_table[];
 197 #endif
 198 #ifdef CONFIG_EPOLL
 199 extern struct ctl_table epoll_table[];
 200 #endif
 201
 202 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 203 int sysctl_legacy_va_layout;
 204 #endif
 205
 206 extern int prove_locking;
 207 extern int lock_stat;
 208
 209 /* The default sysctl tables: */
 210
 211 static struct ctl_table root_table[] = {
 212         {
 213                 .ctl_name       = CTL_KERN,
 214                 .procname       = "kernel",
 215                 .mode           = 0555,
 216                 .child          = kern_table,
 217         },
 218         {
 219                 .ctl_name       = CTL_VM,
 220                 .procname       = "vm",
 221                 .mode           = 0555,
 222                 .child          = vm_table,
 223         },
 224         {
 225                 .ctl_name       = CTL_FS,
 226                 .procname       = "fs",
 227                 .mode           = 0555,
 228                 .child          = fs_table,
 229         },
 230         {
 231                 .ctl_name       = CTL_DEBUG,
 232                 .procname       = "debug",
 233                 .mode           = 0555,
 234                 .child          = debug_table,
 235         },
 236         {
 237                 .ctl_name       = CTL_DEV,
 238                 .procname       = "dev",
 239                 .mode           = 0555,
 240                 .child          = dev_table,
 241         },
 242 /*
 243  * NOTE: do not add new entries to this table unless you have read
 244  * Documentation/sysctl/ctl_unnumbered.txt
 245  */
 246         { .ctl_name = 0 }
 247 };
 248
 249 #ifdef CONFIG_SCHED_DEBUG
 250 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 251 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 252 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 253 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 254 #endif
 255
 256 static struct ctl_table kern_table[] = {
 257         {
 258                 .ctl_name       = CTL_UNNUMBERED,
 259                 .procname       = "sched_child_runs_first",
 260                 .data           = &sysctl_sched_child_runs_first,
 261                 .maxlen         = sizeof(unsigned int),
 262                 .mode           = 0644,
 263                 .proc_handler   = &proc_dointvec,
 264         },
 265 #ifdef CONFIG_SCHED_DEBUG
 266         {
 267                 .ctl_name       = CTL_UNNUMBERED,
 268                 .procname       = "sched_min_granularity_ns",
 269                 .data           = &sysctl_sched_min_granularity,
 270                 .maxlen         = sizeof(unsigned int),
 271                 .mode           = 0644,
 272                 .proc_handler   = &sched_nr_latency_handler,
 273                 .strategy       = &sysctl_intvec,
 274                 .extra1         = &min_sched_granularity_ns,
 275                 .extra2         = &max_sched_granularity_ns,
 276         },
 277         {
 278                 .ctl_name       = CTL_UNNUMBERED,
 279                 .procname       = "sched_latency_ns",
 280                 .data           = &sysctl_sched_latency,
 281                 .maxlen         = sizeof(unsigned int),
 282                 .mode           = 0644,
 283                 .proc_handler   = &sched_nr_latency_handler,
 284                 .strategy       = &sysctl_intvec,
 285                 .extra1         = &min_sched_granularity_ns,
 286                 .extra2         = &max_sched_granularity_ns,
 287         },
 288         {
 289                 .ctl_name       = CTL_UNNUMBERED,
 290                 .procname       = "sched_wakeup_granularity_ns",
 291                 .data           = &sysctl_sched_wakeup_granularity,
 292                 .maxlen         = sizeof(unsigned int),
 293                 .mode           = 0644,
 294                 .proc_handler   = &proc_dointvec_minmax,
 295                 .strategy       = &sysctl_intvec,
 296                 .extra1         = &min_wakeup_granularity_ns,
 297                 .extra2         = &max_wakeup_granularity_ns,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_shares_ratelimit",
 302                 .data           = &sysctl_sched_shares_ratelimit,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec,
 306         },
 307         {
 308                 .ctl_name       = CTL_UNNUMBERED,
 309                 .procname       = "sched_shares_thresh",
 310                 .data           = &sysctl_sched_shares_thresh,
 311                 .maxlen         = sizeof(unsigned int),
 312                 .mode           = 0644,
 313                 .proc_handler   = &proc_dointvec_minmax,
 314                 .strategy       = &sysctl_intvec,
 315                 .extra1         = &zero,
 316         },
 317         {
 318                 .ctl_name       = CTL_UNNUMBERED,
 319                 .procname       = "sched_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         {
 423                 .ctl_name       = CTL_UNNUMBERED,
 424                 .procname       = "core_pipe_limit",
 425                 .data           = &core_pipe_limit,
 426                 .maxlen         = sizeof(unsigned int),
 427                 .mode           = 0644,
 428                 .proc_handler   = &proc_dointvec,
 429         },
 430 #ifdef CONFIG_PROC_SYSCTL
 431         {
 432                 .procname       = "tainted",
 433                 .maxlen         = sizeof(long),
 434                 .mode           = 0644,
 435                 .proc_handler   = &proc_taint,
 436         },
 437 #endif
 438 #ifdef CONFIG_LATENCYTOP
 439         {
 440                 .procname       = "latencytop",
 441                 .data           = &latencytop_enabled,
 442                 .maxlen         = sizeof(int),
 443                 .mode           = 0644,
 444                 .proc_handler   = &proc_dointvec,
 445         },
 446 #endif
 447 #ifdef CONFIG_BLK_DEV_INITRD
 448         {
 449                 .ctl_name       = KERN_REALROOTDEV,
 450                 .procname       = "real-root-dev",
 451                 .data           = &real_root_dev,
 452                 .maxlen         = sizeof(int),
 453                 .mode           = 0644,
 454                 .proc_handler   = &proc_dointvec,
 455         },
 456 #endif
 457         {
 458                 .ctl_name       = CTL_UNNUMBERED,
 459                 .procname       = "print-fatal-signals",
 460                 .data           = &print_fatal_signals,
 461                 .maxlen         = sizeof(int),
 462                 .mode           = 0644,
 463                 .proc_handler   = &proc_dointvec,
 464         },
 465 #ifdef CONFIG_SPARC
 466         {
 467                 .ctl_name       = KERN_SPARC_REBOOT,
 468                 .procname       = "reboot-cmd",
 469                 .data           = reboot_command,
 470                 .maxlen         = 256,
 471                 .mode           = 0644,
 472                 .proc_handler   = &proc_dostring,
 473                 .strategy       = &sysctl_string,
 474         },
 475         {
 476                 .ctl_name       = KERN_SPARC_STOP_A,
 477                 .procname       = "stop-a",
 478                 .data           = &stop_a_enabled,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = &proc_dointvec,
 482         },
 483         {
 484                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 485                 .procname       = "scons-poweroff",
 486                 .data           = &scons_pwroff,
 487                 .maxlen         = sizeof (int),
 488                 .mode           = 0644,
 489                 .proc_handler   = &proc_dointvec,
 490         },
 491 #endif
 492 #ifdef CONFIG_SPARC64
 493         {
 494                 .ctl_name       = CTL_UNNUMBERED,
 495                 .procname       = "tsb-ratio",
 496                 .data           = &sysctl_tsb_ratio,
 497                 .maxlen         = sizeof (int),
 498                 .mode           = 0644,
 499                 .proc_handler   = &proc_dointvec,
 500         },
 501 #endif
 502 #ifdef __hppa__
 503         {
 504                 .ctl_name       = KERN_HPPA_PWRSW,
 505                 .procname       = "soft-power",
 506                 .data           = &pwrsw_enabled,
 507                 .maxlen         = sizeof (int),
 508                 .mode           = 0644,
 509                 .proc_handler   = &proc_dointvec,
 510         },
 511         {
 512                 .ctl_name       = KERN_HPPA_UNALIGNED,
 513                 .procname       = "unaligned-trap",
 514                 .data           = &unaligned_enabled,
 515                 .maxlen         = sizeof (int),
 516                 .mode           = 0644,
 517                 .proc_handler   = &proc_dointvec,
 518         },
 519 #endif
 520         {
 521                 .ctl_name       = KERN_CTLALTDEL,
 522                 .procname       = "ctrl-alt-del",
 523                 .data           = &C_A_D,
 524                 .maxlen         = sizeof(int),
 525                 .mode           = 0644,
 526                 .proc_handler   = &proc_dointvec,
 527         },
 528 #ifdef CONFIG_FUNCTION_TRACER
 529         {
 530                 .ctl_name       = CTL_UNNUMBERED,
 531                 .procname       = "ftrace_enabled",
 532                 .data           = &ftrace_enabled,
 533                 .maxlen         = sizeof(int),
 534                 .mode           = 0644,
 535                 .proc_handler   = &ftrace_enable_sysctl,
 536         },
 537 #endif
 538 #ifdef CONFIG_STACK_TRACER
 539         {
 540                 .ctl_name       = CTL_UNNUMBERED,
 541                 .procname       = "stack_tracer_enabled",
 542                 .data           = &stack_tracer_enabled,
 543                 .maxlen         = sizeof(int),
 544                 .mode           = 0644,
 545                 .proc_handler   = &stack_trace_sysctl,
 546         },
 547 #endif
 548 #ifdef CONFIG_TRACING
 549         {
 550                 .ctl_name       = CTL_UNNUMBERED,
 551                 .procname       = "ftrace_dump_on_oops",
 552                 .data           = &ftrace_dump_on_oops,
 553                 .maxlen         = sizeof(int),
 554                 .mode           = 0644,
 555                 .proc_handler   = &proc_dointvec,
 556         },
 557 #endif
 558 #ifdef CONFIG_MODULES
 559         {
 560                 .ctl_name       = KERN_MODPROBE,
 561                 .procname       = "modprobe",
 562                 .data           = &modprobe_path,
 563                 .maxlen         = KMOD_PATH_LEN,
 564                 .mode           = 0644,
 565                 .proc_handler   = &proc_dostring,
 566                 .strategy       = &sysctl_string,
 567         },
 568         {
 569                 .ctl_name       = CTL_UNNUMBERED,
 570                 .procname       = "modules_disabled",
 571                 .data           = &modules_disabled,
 572                 .maxlen         = sizeof(int),
 573                 .mode           = 0644,
 574                 /* only handle a transition from default "0" to "1" */
 575                 .proc_handler   = &proc_dointvec_minmax,
 576                 .extra1         = &one,
 577                 .extra2         = &one,
 578         },
 579 #endif
 580 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 581         {
 582                 .ctl_name       = KERN_HOTPLUG,
 583                 .procname       = "hotplug",
 584                 .data           = &uevent_helper,
 585                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dostring,
 588                 .strategy       = &sysctl_string,
 589         },
 590 #endif
 591 #ifdef CONFIG_CHR_DEV_SG
 592         {
 593                 .ctl_name       = KERN_SG_BIG_BUFF,
 594                 .procname       = "sg-big-buff",
 595                 .data           = &sg_big_buff,
 596                 .maxlen         = sizeof (int),
 597                 .mode           = 0444,
 598                 .proc_handler   = &proc_dointvec,
 599         },
 600 #endif
 601 #ifdef CONFIG_BSD_PROCESS_ACCT
 602         {
 603                 .ctl_name       = KERN_ACCT,
 604                 .procname       = "acct",
 605                 .data           = &acct_parm,
 606                 .maxlen         = 3*sizeof(int),
 607                 .mode           = 0644,
 608                 .proc_handler   = &proc_dointvec,
 609         },
 610 #endif
 611 #ifdef CONFIG_MAGIC_SYSRQ
 612         {
 613                 .ctl_name       = KERN_SYSRQ,
 614                 .procname       = "sysrq",
 615                 .data           = &__sysrq_enabled,
 616                 .maxlen         = sizeof (int),
 617                 .mode           = 0644,
 618                 .proc_handler   = &proc_dointvec,
 619         },
 620 #endif
 621 #ifdef CONFIG_PROC_SYSCTL
 622         {
 623                 .procname       = "cad_pid",
 624                 .data           = NULL,
 625                 .maxlen         = sizeof (int),
 626                 .mode           = 0600,
 627                 .proc_handler   = &proc_do_cad_pid,
 628         },
 629 #endif
 630         {
 631                 .ctl_name       = KERN_MAX_THREADS,
 632                 .procname       = "threads-max",
 633                 .data           = &max_threads,
 634                 .maxlen         = sizeof(int),
 635                 .mode           = 0644,
 636                 .proc_handler   = &proc_dointvec,
 637         },
 638         {
 639                 .ctl_name       = KERN_RANDOM,
 640                 .procname       = "random",
 641                 .mode           = 0555,
 642                 .child          = random_table,
 643         },
 644         {
 645                 .ctl_name       = KERN_OVERFLOWUID,
 646                 .procname       = "overflowuid",
 647                 .data           = &overflowuid,
 648                 .maxlen         = sizeof(int),
 649                 .mode           = 0644,
 650                 .proc_handler   = &proc_dointvec_minmax,
 651                 .strategy       = &sysctl_intvec,
 652                 .extra1         = &minolduid,
 653                 .extra2         = &maxolduid,
 654         },
 655         {
 656                 .ctl_name       = KERN_OVERFLOWGID,
 657                 .procname       = "overflowgid",
 658                 .data           = &overflowgid,
 659                 .maxlen         = sizeof(int),
 660                 .mode           = 0644,
 661                 .proc_handler   = &proc_dointvec_minmax,
 662                 .strategy       = &sysctl_intvec,
 663                 .extra1         = &minolduid,
 664                 .extra2         = &maxolduid,
 665         },
 666 #ifdef CONFIG_S390
 667 #ifdef CONFIG_MATHEMU
 668         {
 669                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 670                 .procname       = "ieee_emulation_warnings",
 671                 .data           = &sysctl_ieee_emulation_warnings,
 672                 .maxlen         = sizeof(int),
 673                 .mode           = 0644,
 674                 .proc_handler   = &proc_dointvec,
 675         },
 676 #endif
 677         {
 678                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 679                 .procname       = "userprocess_debug",
 680                 .data           = &sysctl_userprocess_debug,
 681                 .maxlen         = sizeof(int),
 682                 .mode           = 0644,
 683                 .proc_handler   = &proc_dointvec,
 684         },
 685 #endif
 686         {
 687                 .ctl_name       = KERN_PIDMAX,
 688                 .procname       = "pid_max",
 689                 .data           = &pid_max,
 690                 .maxlen         = sizeof (int),
 691                 .mode           = 0644,
 692                 .proc_handler   = &proc_dointvec_minmax,
 693                 .strategy       = sysctl_intvec,
 694                 .extra1         = &pid_max_min,
 695                 .extra2         = &pid_max_max,
 696         },
 697         {
 698                 .ctl_name       = KERN_PANIC_ON_OOPS,
 699                 .procname       = "panic_on_oops",
 700                 .data           = &panic_on_oops,
 701                 .maxlen         = sizeof(int),
 702                 .mode           = 0644,
 703                 .proc_handler   = &proc_dointvec,
 704         },
 705 #if defined CONFIG_PRINTK
 706         {
 707                 .ctl_name       = KERN_PRINTK,
 708                 .procname       = "printk",
 709                 .data           = &console_loglevel,
 710                 .maxlen         = 4*sizeof(int),
 711                 .mode           = 0644,
 712                 .proc_handler   = &proc_dointvec,
 713         },
 714         {
 715                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 716                 .procname       = "printk_ratelimit",
 717                 .data           = &printk_ratelimit_state.interval,
 718                 .maxlen         = sizeof(int),
 719                 .mode           = 0644,
 720                 .proc_handler   = &proc_dointvec_jiffies,
 721                 .strategy       = &sysctl_jiffies,
 722         },
 723         {
 724                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 725                 .procname       = "printk_ratelimit_burst",
 726                 .data           = &printk_ratelimit_state.burst,
 727                 .maxlen         = sizeof(int),
 728                 .mode           = 0644,
 729                 .proc_handler   = &proc_dointvec,
 730         },
 731         {
 732                 .ctl_name       = CTL_UNNUMBERED,
 733                 .procname       = "printk_delay",
 734                 .data           = &printk_delay_msec,
 735                 .maxlen         = sizeof(int),
 736                 .mode           = 0644,
 737                 .proc_handler   = &proc_dointvec_minmax,
 738                 .strategy       = &sysctl_intvec,
 739                 .extra1         = &zero,
 740                 .extra2         = &ten_thousand,
 741         },
 742 #endif
 743         {
 744                 .ctl_name       = KERN_NGROUPS_MAX,
 745                 .procname       = "ngroups_max",
 746                 .data           = &ngroups_max,
 747                 .maxlen         = sizeof (int),
 748                 .mode           = 0444,
 749                 .proc_handler   = &proc_dointvec,
 750         },
 751 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 752         {
 753                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 754                 .procname       = "unknown_nmi_panic",
 755                 .data           = &unknown_nmi_panic,
 756                 .maxlen         = sizeof (int),
 757                 .mode           = 0644,
 758                 .proc_handler   = &proc_dointvec,
 759         },
 760         {
 761                 .procname       = "nmi_watchdog",
 762                 .data           = &nmi_watchdog_enabled,
 763                 .maxlen         = sizeof (int),
 764                 .mode           = 0644,
 765                 .proc_handler   = &proc_nmi_enabled,
 766         },
 767 #endif
 768 #if defined(CONFIG_X86)
 769         {
 770                 .ctl_name       = KERN_PANIC_ON_NMI,
 771                 .procname       = "panic_on_unrecovered_nmi",
 772                 .data           = &panic_on_unrecovered_nmi,
 773                 .maxlen         = sizeof(int),
 774                 .mode           = 0644,
 775                 .proc_handler   = &proc_dointvec,
 776         },
 777         {
 778                 .ctl_name       = CTL_UNNUMBERED,
 779                 .procname       = "panic_on_io_nmi",
 780                 .data           = &panic_on_io_nmi,
 781                 .maxlen         = sizeof(int),
 782                 .mode           = 0644,
 783                 .proc_handler   = &proc_dointvec,
 784         },
 785         {
 786                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 787                 .procname       = "bootloader_type",
 788                 .data           = &bootloader_type,
 789                 .maxlen         = sizeof (int),
 790                 .mode           = 0444,
 791                 .proc_handler   = &proc_dointvec,
 792         },
 793         {
 794                 .ctl_name       = CTL_UNNUMBERED,
 795                 .procname       = "bootloader_version",
 796                 .data           = &bootloader_version,
 797                 .maxlen         = sizeof (int),
 798                 .mode           = 0444,
 799                 .proc_handler   = &proc_dointvec,
 800         },
 801         {
 802                 .ctl_name       = CTL_UNNUMBERED,
 803                 .procname       = "kstack_depth_to_print",
 804                 .data           = &kstack_depth_to_print,
 805                 .maxlen         = sizeof(int),
 806                 .mode           = 0644,
 807                 .proc_handler   = &proc_dointvec,
 808         },
 809         {
 810                 .ctl_name       = CTL_UNNUMBERED,
 811                 .procname       = "io_delay_type",
 812                 .data           = &io_delay_type,
 813                 .maxlen         = sizeof(int),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dointvec,
 816         },
 817 #endif
 818 #if defined(CONFIG_MMU)
 819         {
 820                 .ctl_name       = KERN_RANDOMIZE,
 821                 .procname       = "randomize_va_space",
 822                 .data           = &randomize_va_space,
 823                 .maxlen         = sizeof(int),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_dointvec,
 826         },
 827 #endif
 828 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 829         {
 830                 .ctl_name       = KERN_SPIN_RETRY,
 831                 .procname       = "spin_retry",
 832                 .data           = &spin_retry,
 833                 .maxlen         = sizeof (int),
 834                 .mode           = 0644,
 835                 .proc_handler   = &proc_dointvec,
 836         },
 837 #endif
 838 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 839         {
 840                 .procname       = "acpi_video_flags",
 841                 .data           = &acpi_realmode_flags,
 842                 .maxlen         = sizeof (unsigned long),
 843                 .mode           = 0644,
 844                 .proc_handler   = &proc_doulongvec_minmax,
 845         },
 846 #endif
 847 #ifdef CONFIG_IA64
 848         {
 849                 .ctl_name       = KERN_IA64_UNALIGNED,
 850                 .procname       = "ignore-unaligned-usertrap",
 851                 .data           = &no_unaligned_warning,
 852                 .maxlen         = sizeof (int),
 853                 .mode           = 0644,
 854                 .proc_handler   = &proc_dointvec,
 855         },
 856         {
 857                 .ctl_name       = CTL_UNNUMBERED,
 858                 .procname       = "unaligned-dump-stack",
 859                 .data           = &unaligned_dump_stack,
 860                 .maxlen         = sizeof (int),
 861                 .mode           = 0644,
 862                 .proc_handler   = &proc_dointvec,
 863         },
 864 #endif
 865 #ifdef CONFIG_DETECT_SOFTLOCKUP
 866         {
 867                 .ctl_name       = CTL_UNNUMBERED,
 868                 .procname       = "softlockup_panic",
 869                 .data           = &softlockup_panic,
 870                 .maxlen         = sizeof(int),
 871                 .mode           = 0644,
 872                 .proc_handler   = &proc_dointvec_minmax,
 873                 .strategy       = &sysctl_intvec,
 874                 .extra1         = &zero,
 875                 .extra2         = &one,
 876         },
 877         {
 878                 .ctl_name       = CTL_UNNUMBERED,
 879                 .procname       = "softlockup_thresh",
 880                 .data           = &softlockup_thresh,
 881                 .maxlen         = sizeof(int),
 882                 .mode           = 0644,
 883                 .proc_handler   = &proc_dosoftlockup_thresh,
 884                 .strategy       = &sysctl_intvec,
 885                 .extra1         = &neg_one,
 886                 .extra2         = &sixty,
 887         },
 888 #endif
 889 #ifdef CONFIG_DETECT_HUNG_TASK
 890         {
 891                 .ctl_name       = CTL_UNNUMBERED,
 892                 .procname       = "hung_task_panic",
 893                 .data           = &sysctl_hung_task_panic,
 894                 .maxlen         = sizeof(int),
 895                 .mode           = 0644,
 896                 .proc_handler   = &proc_dointvec_minmax,
 897                 .strategy       = &sysctl_intvec,
 898                 .extra1         = &zero,
 899                 .extra2         = &one,
 900         },
 901         {
 902                 .ctl_name       = CTL_UNNUMBERED,
 903                 .procname       = "hung_task_check_count",
 904                 .data           = &sysctl_hung_task_check_count,
 905                 .maxlen         = sizeof(unsigned long),
 906                 .mode           = 0644,
 907                 .proc_handler   = &proc_doulongvec_minmax,
 908                 .strategy       = &sysctl_intvec,
 909         },
 910         {
 911                 .ctl_name       = CTL_UNNUMBERED,
 912                 .procname       = "hung_task_timeout_secs",
 913                 .data           = &sysctl_hung_task_timeout_secs,
 914                 .maxlen         = sizeof(unsigned long),
 915                 .mode           = 0644,
 916                 .proc_handler   = &proc_dohung_task_timeout_secs,
 917                 .strategy       = &sysctl_intvec,
 918         },
 919         {
 920                 .ctl_name       = CTL_UNNUMBERED,
 921                 .procname       = "hung_task_warnings",
 922                 .data           = &sysctl_hung_task_warnings,
 923                 .maxlen         = sizeof(unsigned long),
 924                 .mode           = 0644,
 925                 .proc_handler   = &proc_doulongvec_minmax,
 926                 .strategy       = &sysctl_intvec,
 927         },
 928 #endif
 929 #ifdef CONFIG_COMPAT
 930         {
 931                 .ctl_name       = KERN_COMPAT_LOG,
 932                 .procname       = "compat-log",
 933                 .data           = &compat_log,
 934                 .maxlen         = sizeof (int),
 935                 .mode           = 0644,
 936                 .proc_handler   = &proc_dointvec,
 937         },
 938 #endif
 939 #ifdef CONFIG_RT_MUTEXES
 940         {
 941                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 942                 .procname       = "max_lock_depth",
 943                 .data           = &max_lock_depth,
 944                 .maxlen         = sizeof(int),
 945                 .mode           = 0644,
 946                 .proc_handler   = &proc_dointvec,
 947         },
 948 #endif
 949         {
 950                 .ctl_name       = CTL_UNNUMBERED,
 951                 .procname       = "poweroff_cmd",
 952                 .data           = &poweroff_cmd,
 953                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 954                 .mode           = 0644,
 955                 .proc_handler   = &proc_dostring,
 956                 .strategy       = &sysctl_string,
 957         },
 958 #ifdef CONFIG_KEYS
 959         {
 960                 .ctl_name       = CTL_UNNUMBERED,
 961                 .procname       = "keys",
 962                 .mode           = 0555,
 963                 .child          = key_sysctls,
 964         },
 965 #endif
 966 #ifdef CONFIG_RCU_TORTURE_TEST
 967         {
 968                 .ctl_name       = CTL_UNNUMBERED,
 969                 .procname       = "rcutorture_runnable",
 970                 .data           = &rcutorture_runnable,
 971                 .maxlen         = sizeof(int),
 972                 .mode           = 0644,
 973                 .proc_handler   = &proc_dointvec,
 974         },
 975 #endif
 976 #ifdef CONFIG_SLOW_WORK
 977         {
 978                 .ctl_name       = CTL_UNNUMBERED,
 979                 .procname       = "slow-work",
 980                 .mode           = 0555,
 981                 .child          = slow_work_sysctls,
 982         },
 983 #endif
 984 #ifdef CONFIG_PERF_EVENTS
 985         {
 986                 .ctl_name       = CTL_UNNUMBERED,
 987                 .procname       = "perf_event_paranoid",
 988                 .data           = &sysctl_perf_event_paranoid,
 989                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 990                 .mode           = 0644,
 991                 .proc_handler   = &proc_dointvec,
 992         },
 993         {
 994                 .ctl_name       = CTL_UNNUMBERED,
 995                 .procname       = "perf_event_mlock_kb",
 996                 .data           = &sysctl_perf_event_mlock,
 997                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 998                 .mode           = 0644,
 999                 .proc_handler   = &proc_dointvec,
1000         },
1001         {
1002                 .ctl_name       = CTL_UNNUMBERED,
1003                 .procname       = "perf_event_max_sample_rate",
1004                 .data           = &sysctl_perf_event_sample_rate,
1005                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
1006                 .mode           = 0644,
1007                 .proc_handler   = &proc_dointvec,
1008         },
1009 #endif
1010 #ifdef CONFIG_KMEMCHECK
1011         {
1012                 .ctl_name       = CTL_UNNUMBERED,
1013                 .procname       = "kmemcheck",
1014                 .data           = &kmemcheck_enabled,
1015                 .maxlen         = sizeof(int),
1016                 .mode           = 0644,
1017                 .proc_handler   = &proc_dointvec,
1018         },
1019 #endif
1020 #ifdef CONFIG_BLOCK
1021         {
1022                 .ctl_name       = CTL_UNNUMBERED,
1023                 .procname       = "blk_iopoll",
1024                 .data           = &blk_iopoll_enabled,
1025                 .maxlen         = sizeof(int),
1026                 .mode           = 0644,
1027                 .proc_handler   = &proc_dointvec,
1028         },
1029 #endif
1030 /*
1031  * NOTE: do not add new entries to this table unless you have read
1032  * Documentation/sysctl/ctl_unnumbered.txt
1033  */
1034         { .ctl_name = 0 }
1035 };
1036
1037 static struct ctl_table vm_table[] = {
1038         {
1039                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
1040                 .procname       = "overcommit_memory",
1041                 .data           = &sysctl_overcommit_memory,
1042                 .maxlen         = sizeof(sysctl_overcommit_memory),
1043                 .mode           = 0644,
1044                 .proc_handler   = &proc_dointvec,
1045         },
1046         {
1047                 .ctl_name       = VM_PANIC_ON_OOM,
1048                 .procname       = "panic_on_oom",
1049                 .data           = &sysctl_panic_on_oom,
1050                 .maxlen         = sizeof(sysctl_panic_on_oom),
1051                 .mode           = 0644,
1052                 .proc_handler   = &proc_dointvec,
1053         },
1054         {
1055                 .ctl_name       = CTL_UNNUMBERED,
1056                 .procname       = "oom_kill_allocating_task",
1057                 .data           = &sysctl_oom_kill_allocating_task,
1058                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1059                 .mode           = 0644,
1060                 .proc_handler   = &proc_dointvec,
1061         },
1062         {
1063                 .ctl_name       = CTL_UNNUMBERED,
1064                 .procname       = "oom_dump_tasks",
1065                 .data           = &sysctl_oom_dump_tasks,
1066                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1067                 .mode           = 0644,
1068                 .proc_handler   = &proc_dointvec,
1069         },
1070         {
1071                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1072                 .procname       = "overcommit_ratio",
1073                 .data           = &sysctl_overcommit_ratio,
1074                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1075                 .mode           = 0644,
1076                 .proc_handler   = &proc_dointvec,
1077         },
1078         {
1079                 .ctl_name       = VM_PAGE_CLUSTER,
1080                 .procname       = "page-cluster",
1081                 .data           = &page_cluster,
1082                 .maxlen         = sizeof(int),
1083                 .mode           = 0644,
1084                 .proc_handler   = &proc_dointvec,
1085         },
1086         {
1087                 .ctl_name       = VM_DIRTY_BACKGROUND,
1088                 .procname       = "dirty_background_ratio",
1089                 .data           = &dirty_background_ratio,
1090                 .maxlen         = sizeof(dirty_background_ratio),
1091                 .mode           = 0644,
1092                 .proc_handler   = &dirty_background_ratio_handler,
1093                 .strategy       = &sysctl_intvec,
1094                 .extra1         = &zero,
1095                 .extra2         = &one_hundred,
1096         },
1097         {
1098                 .ctl_name       = CTL_UNNUMBERED,
1099                 .procname       = "dirty_background_bytes",
1100                 .data           = &dirty_background_bytes,
1101                 .maxlen         = sizeof(dirty_background_bytes),
1102                 .mode           = 0644,
1103                 .proc_handler   = &dirty_background_bytes_handler,
1104                 .strategy       = &sysctl_intvec,
1105                 .extra1         = &one_ul,
1106         },
1107         {
1108                 .ctl_name       = VM_DIRTY_RATIO,
1109                 .procname       = "dirty_ratio",
1110                 .data           = &vm_dirty_ratio,
1111                 .maxlen         = sizeof(vm_dirty_ratio),
1112                 .mode           = 0644,
1113                 .proc_handler   = &dirty_ratio_handler,
1114                 .strategy       = &sysctl_intvec,
1115                 .extra1         = &zero,
1116                 .extra2         = &one_hundred,
1117         },
1118         {
1119                 .ctl_name       = CTL_UNNUMBERED,
1120                 .procname       = "dirty_bytes",
1121                 .data           = &vm_dirty_bytes,
1122                 .maxlen         = sizeof(vm_dirty_bytes),
1123                 .mode           = 0644,
1124                 .proc_handler   = &dirty_bytes_handler,
1125                 .strategy       = &sysctl_intvec,
1126                 .extra1         = &dirty_bytes_min,
1127         },
1128         {
1129                 .procname       = "dirty_writeback_centisecs",
1130                 .data           = &dirty_writeback_interval,
1131                 .maxlen         = sizeof(dirty_writeback_interval),
1132                 .mode           = 0644,
1133                 .proc_handler   = &dirty_writeback_centisecs_handler,
1134         },
1135         {
1136                 .procname       = "dirty_expire_centisecs",
1137                 .data           = &dirty_expire_interval,
1138                 .maxlen         = sizeof(dirty_expire_interval),
1139                 .mode           = 0644,
1140                 .proc_handler   = &proc_dointvec,
1141         },
1142         {
1143                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1144                 .procname       = "nr_pdflush_threads",
1145                 .data           = &nr_pdflush_threads,
1146                 .maxlen         = sizeof nr_pdflush_threads,
1147                 .mode           = 0444 /* read-only*/,
1148                 .proc_handler   = &proc_dointvec,
1149         },
1150         {
1151                 .ctl_name       = VM_SWAPPINESS,
1152                 .procname       = "swappiness",
1153                 .data           = &vm_swappiness,
1154                 .maxlen         = sizeof(vm_swappiness),
1155                 .mode           = 0644,
1156                 .proc_handler   = &proc_dointvec_minmax,
1157                 .strategy       = &sysctl_intvec,
1158                 .extra1         = &zero,
1159                 .extra2         = &one_hundred,
1160         },
1161 #ifdef CONFIG_HUGETLB_PAGE
1162          {
1163                 .procname       = "nr_hugepages",
1164                 .data           = NULL,
1165                 .maxlen         = sizeof(unsigned long),
1166                 .mode           = 0644,
1167                 .proc_handler   = &hugetlb_sysctl_handler,
1168                 .extra1         = (void *)&hugetlb_zero,
1169                 .extra2         = (void *)&hugetlb_infinity,
1170          },
1171          {
1172                 .ctl_name       = VM_HUGETLB_GROUP,
1173                 .procname       = "hugetlb_shm_group",
1174                 .data           = &sysctl_hugetlb_shm_group,
1175                 .maxlen         = sizeof(gid_t),
1176                 .mode           = 0644,
1177                 .proc_handler   = &proc_dointvec,
1178          },
1179          {
1180                 .ctl_name       = CTL_UNNUMBERED,
1181                 .procname       = "hugepages_treat_as_movable",
1182                 .data           = &hugepages_treat_as_movable,
1183                 .maxlen         = sizeof(int),
1184                 .mode           = 0644,
1185                 .proc_handler   = &hugetlb_treat_movable_handler,
1186         },
1187         {
1188                 .ctl_name       = CTL_UNNUMBERED,
1189                 .procname       = "nr_overcommit_hugepages",
1190                 .data           = NULL,
1191                 .maxlen         = sizeof(unsigned long),
1192                 .mode           = 0644,
1193                 .proc_handler   = &hugetlb_overcommit_handler,
1194                 .extra1         = (void *)&hugetlb_zero,
1195                 .extra2         = (void *)&hugetlb_infinity,
1196         },
1197 #endif
1198         {
1199                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1200                 .procname       = "lowmem_reserve_ratio",
1201                 .data           = &sysctl_lowmem_reserve_ratio,
1202                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1203                 .mode           = 0644,
1204                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1205                 .strategy       = &sysctl_intvec,
1206         },
1207         {
1208                 .ctl_name       = VM_DROP_PAGECACHE,
1209                 .procname       = "drop_caches",
1210                 .data           = &sysctl_drop_caches,
1211                 .maxlen         = sizeof(int),
1212                 .mode           = 0644,
1213                 .proc_handler   = drop_caches_sysctl_handler,
1214                 .strategy       = &sysctl_intvec,
1215         },
1216         {
1217                 .ctl_name       = VM_MIN_FREE_KBYTES,
1218                 .procname       = "min_free_kbytes",
1219                 .data           = &min_free_kbytes,
1220                 .maxlen         = sizeof(min_free_kbytes),
1221                 .mode           = 0644,
1222                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1223                 .strategy       = &sysctl_intvec,
1224                 .extra1         = &zero,
1225         },
1226         {
1227                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1228                 .procname       = "percpu_pagelist_fraction",
1229                 .data           = &percpu_pagelist_fraction,
1230                 .maxlen         = sizeof(percpu_pagelist_fraction),
1231                 .mode           = 0644,
1232                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1233                 .strategy       = &sysctl_intvec,
1234                 .extra1         = &min_percpu_pagelist_fract,
1235         },
1236 #ifdef CONFIG_MMU
1237         {
1238                 .ctl_name       = VM_MAX_MAP_COUNT,
1239                 .procname       = "max_map_count",
1240                 .data           = &sysctl_max_map_count,
1241                 .maxlen         = sizeof(sysctl_max_map_count),
1242                 .mode           = 0644,
1243                 .proc_handler   = &proc_dointvec
1244         },
1245 #else
1246         {
1247                 .ctl_name       = CTL_UNNUMBERED,
1248                 .procname       = "nr_trim_pages",
1249                 .data           = &sysctl_nr_trim_pages,
1250                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1251                 .mode           = 0644,
1252                 .proc_handler   = &proc_dointvec_minmax,
1253                 .strategy       = &sysctl_intvec,
1254                 .extra1         = &zero,
1255         },
1256 #endif
1257         {
1258                 .ctl_name       = VM_LAPTOP_MODE,
1259                 .procname       = "laptop_mode",
1260                 .data           = &laptop_mode,
1261                 .maxlen         = sizeof(laptop_mode),
1262                 .mode           = 0644,
1263                 .proc_handler   = &proc_dointvec_jiffies,
1264                 .strategy       = &sysctl_jiffies,
1265         },
1266         {
1267                 .ctl_name       = VM_BLOCK_DUMP,
1268                 .procname       = "block_dump",
1269                 .data           = &block_dump,
1270                 .maxlen         = sizeof(block_dump),
1271                 .mode           = 0644,
1272                 .proc_handler   = &proc_dointvec,
1273                 .strategy       = &sysctl_intvec,
1274                 .extra1         = &zero,
1275         },
1276         {
1277                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1278                 .procname       = "vfs_cache_pressure",
1279                 .data           = &sysctl_vfs_cache_pressure,
1280                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1281                 .mode           = 0644,
1282                 .proc_handler   = &proc_dointvec,
1283                 .strategy       = &sysctl_intvec,
1284                 .extra1         = &zero,
1285         },
1286 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1287         {
1288                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1289                 .procname       = "legacy_va_layout",
1290                 .data           = &sysctl_legacy_va_layout,
1291                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1292                 .mode           = 0644,
1293                 .proc_handler   = &proc_dointvec,
1294                 .strategy       = &sysctl_intvec,
1295                 .extra1         = &zero,
1296         },
1297 #endif
1298 #ifdef CONFIG_NUMA
1299         {
1300                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1301                 .procname       = "zone_reclaim_mode",
1302                 .data           = &zone_reclaim_mode,
1303                 .maxlen         = sizeof(zone_reclaim_mode),
1304                 .mode           = 0644,
1305                 .proc_handler   = &proc_dointvec,
1306                 .strategy       = &sysctl_intvec,
1307                 .extra1         = &zero,
1308         },
1309         {
1310                 .ctl_name       = VM_MIN_UNMAPPED,
1311                 .procname       = "min_unmapped_ratio",
1312                 .data           = &sysctl_min_unmapped_ratio,
1313                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1314                 .mode           = 0644,
1315                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1316                 .strategy       = &sysctl_intvec,
1317                 .extra1         = &zero,
1318                 .extra2         = &one_hundred,
1319         },
1320         {
1321                 .ctl_name       = VM_MIN_SLAB,
1322                 .procname       = "min_slab_ratio",
1323                 .data           = &sysctl_min_slab_ratio,
1324                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1325                 .mode           = 0644,
1326                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1327                 .strategy       = &sysctl_intvec,
1328                 .extra1         = &zero,
1329                 .extra2         = &one_hundred,
1330         },
1331 #endif
1332 #ifdef CONFIG_SMP
1333         {
1334                 .ctl_name       = CTL_UNNUMBERED,
1335                 .procname       = "stat_interval",
1336                 .data           = &sysctl_stat_interval,
1337                 .maxlen         = sizeof(sysctl_stat_interval),
1338                 .mode           = 0644,
1339                 .proc_handler   = &proc_dointvec_jiffies,
1340                 .strategy       = &sysctl_jiffies,
1341         },
1342 #endif
1343         {
1344                 .ctl_name       = CTL_UNNUMBERED,
1345                 .procname       = "mmap_min_addr",
1346                 .data           = &dac_mmap_min_addr,
1347                 .maxlen         = sizeof(unsigned long),
1348                 .mode           = 0644,
1349                 .proc_handler   = &mmap_min_addr_handler,
1350         },
1351 #ifdef CONFIG_NUMA
1352         {
1353                 .ctl_name       = CTL_UNNUMBERED,
1354                 .procname       = "numa_zonelist_order",
1355                 .data           = &numa_zonelist_order,
1356                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1357                 .mode           = 0644,
1358                 .proc_handler   = &numa_zonelist_order_handler,
1359                 .strategy       = &sysctl_string,
1360         },
1361 #endif
1362 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1363    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1364         {
1365                 .ctl_name       = VM_VDSO_ENABLED,
1366                 .procname       = "vdso_enabled",
1367                 .data           = &vdso_enabled,
1368                 .maxlen         = sizeof(vdso_enabled),
1369                 .mode           = 0644,
1370                 .proc_handler   = &proc_dointvec,
1371                 .strategy       = &sysctl_intvec,
1372                 .extra1         = &zero,
1373         },
1374 #endif
1375 #ifdef CONFIG_HIGHMEM
1376         {
1377                 .ctl_name       = CTL_UNNUMBERED,
1378                 .procname       = "highmem_is_dirtyable",
1379                 .data           = &vm_highmem_is_dirtyable,
1380                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1381                 .mode           = 0644,
1382                 .proc_handler   = &proc_dointvec_minmax,
1383                 .strategy       = &sysctl_intvec,
1384                 .extra1         = &zero,
1385                 .extra2         = &one,
1386         },
1387 #endif
1388         {
1389                 .ctl_name       = CTL_UNNUMBERED,
1390                 .procname       = "scan_unevictable_pages",
1391                 .data           = &scan_unevictable_pages,
1392                 .maxlen         = sizeof(scan_unevictable_pages),
1393                 .mode           = 0644,
1394                 .proc_handler   = &scan_unevictable_handler,
1395         },
1396 #ifdef CONFIG_MEMORY_FAILURE
1397         {
1398                 .ctl_name       = CTL_UNNUMBERED,
1399                 .procname       = "memory_failure_early_kill",
1400                 .data           = &sysctl_memory_failure_early_kill,
1401                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1402                 .mode           = 0644,
1403                 .proc_handler   = &proc_dointvec_minmax,
1404                 .strategy       = &sysctl_intvec,
1405                 .extra1         = &zero,
1406                 .extra2         = &one,
1407         },
1408         {
1409                 .ctl_name       = CTL_UNNUMBERED,
1410                 .procname       = "memory_failure_recovery",
1411                 .data           = &sysctl_memory_failure_recovery,
1412                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1413                 .mode           = 0644,
1414                 .proc_handler   = &proc_dointvec_minmax,
1415                 .strategy       = &sysctl_intvec,
1416                 .extra1         = &zero,
1417                 .extra2         = &one,
1418         },
1419 #endif
1420
1421 /*
1422  * NOTE: do not add new entries to this table unless you have read
1423  * Documentation/sysctl/ctl_unnumbered.txt
1424  */
1425         { .ctl_name = 0 }
1426 };
1427
1428 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1429 static struct ctl_table binfmt_misc_table[] = {
1430         { .ctl_name = 0 }
1431 };
1432 #endif
1433
1434 static struct ctl_table fs_table[] = {
1435         {
1436                 .ctl_name       = FS_NRINODE,
1437                 .procname       = "inode-nr",
1438                 .data           = &inodes_stat,
1439                 .maxlen         = 2*sizeof(int),
1440                 .mode           = 0444,
1441                 .proc_handler   = &proc_dointvec,
1442         },
1443         {
1444                 .ctl_name       = FS_STATINODE,
1445                 .procname       = "inode-state",
1446                 .data           = &inodes_stat,
1447                 .maxlen         = 7*sizeof(int),
1448                 .mode           = 0444,
1449                 .proc_handler   = &proc_dointvec,
1450         },
1451         {
1452                 .procname       = "file-nr",
1453                 .data           = &files_stat,
1454                 .maxlen         = 3*sizeof(int),
1455                 .mode           = 0444,
1456                 .proc_handler   = &proc_nr_files,
1457         },
1458         {
1459                 .ctl_name       = FS_MAXFILE,
1460                 .procname       = "file-max",
1461                 .data           = &files_stat.max_files,
1462                 .maxlen         = sizeof(int),
1463                 .mode           = 0644,
1464                 .proc_handler   = &proc_dointvec,
1465         },
1466         {
1467                 .ctl_name       = CTL_UNNUMBERED,
1468                 .procname       = "nr_open",
1469                 .data           = &sysctl_nr_open,
1470                 .maxlen         = sizeof(int),
1471                 .mode           = 0644,
1472                 .proc_handler   = &proc_dointvec_minmax,
1473                 .extra1         = &sysctl_nr_open_min,
1474                 .extra2         = &sysctl_nr_open_max,
1475         },
1476         {
1477                 .ctl_name       = FS_DENTRY,
1478                 .procname       = "dentry-state",
1479                 .data           = &dentry_stat,
1480                 .maxlen         = 6*sizeof(int),
1481                 .mode           = 0444,
1482                 .proc_handler   = &proc_dointvec,
1483         },
1484         {
1485                 .ctl_name       = FS_OVERFLOWUID,
1486                 .procname       = "overflowuid",
1487                 .data           = &fs_overflowuid,
1488                 .maxlen         = sizeof(int),
1489                 .mode           = 0644,
1490                 .proc_handler   = &proc_dointvec_minmax,
1491                 .strategy       = &sysctl_intvec,
1492                 .extra1         = &minolduid,
1493                 .extra2         = &maxolduid,
1494         },
1495         {
1496                 .ctl_name       = FS_OVERFLOWGID,
1497                 .procname       = "overflowgid",
1498                 .data           = &fs_overflowgid,
1499                 .maxlen         = sizeof(int),
1500                 .mode           = 0644,
1501                 .proc_handler   = &proc_dointvec_minmax,
1502                 .strategy       = &sysctl_intvec,
1503                 .extra1         = &minolduid,
1504                 .extra2         = &maxolduid,
1505         },
1506 #ifdef CONFIG_FILE_LOCKING
1507         {
1508                 .ctl_name       = FS_LEASES,
1509                 .procname       = "leases-enable",
1510                 .data           = &leases_enable,
1511                 .maxlen         = sizeof(int),
1512                 .mode           = 0644,
1513                 .proc_handler   = &proc_dointvec,
1514         },
1515 #endif
1516 #ifdef CONFIG_DNOTIFY
1517         {
1518                 .ctl_name       = FS_DIR_NOTIFY,
1519                 .procname       = "dir-notify-enable",
1520                 .data           = &dir_notify_enable,
1521                 .maxlen         = sizeof(int),
1522                 .mode           = 0644,
1523                 .proc_handler   = &proc_dointvec,
1524         },
1525 #endif
1526 #ifdef CONFIG_MMU
1527 #ifdef CONFIG_FILE_LOCKING
1528         {
1529                 .ctl_name       = FS_LEASE_TIME,
1530                 .procname       = "lease-break-time",
1531                 .data           = &lease_break_time,
1532                 .maxlen         = sizeof(int),
1533                 .mode           = 0644,
1534                 .proc_handler   = &proc_dointvec,
1535         },
1536 #endif
1537 #ifdef CONFIG_AIO
1538         {
1539                 .procname       = "aio-nr",
1540                 .data           = &aio_nr,
1541                 .maxlen         = sizeof(aio_nr),
1542                 .mode           = 0444,
1543                 .proc_handler   = &proc_doulongvec_minmax,
1544         },
1545         {
1546                 .procname       = "aio-max-nr",
1547                 .data           = &aio_max_nr,
1548                 .maxlen         = sizeof(aio_max_nr),
1549                 .mode           = 0644,
1550                 .proc_handler   = &proc_doulongvec_minmax,
1551         },
1552 #endif /* CONFIG_AIO */
1553 #ifdef CONFIG_INOTIFY_USER
1554         {
1555                 .ctl_name       = FS_INOTIFY,
1556                 .procname       = "inotify",
1557                 .mode           = 0555,
1558                 .child          = inotify_table,
1559         },
1560 #endif
1561 #ifdef CONFIG_EPOLL
1562         {
1563                 .procname       = "epoll",
1564                 .mode           = 0555,
1565                 .child          = epoll_table,
1566         },
1567 #endif
1568 #endif
1569         {
1570                 .ctl_name       = KERN_SETUID_DUMPABLE,
1571                 .procname       = "suid_dumpable",
1572                 .data           = &suid_dumpable,
1573                 .maxlen         = sizeof(int),
1574                 .mode           = 0644,
1575                 .proc_handler   = &proc_dointvec_minmax,
1576                 .strategy       = &sysctl_intvec,
1577                 .extra1         = &zero,
1578                 .extra2         = &two,
1579         },
1580 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1581         {
1582                 .ctl_name       = CTL_UNNUMBERED,
1583                 .procname       = "binfmt_misc",
1584                 .mode           = 0555,
1585                 .child          = binfmt_misc_table,
1586         },
1587 #endif
1588 /*
1589  * NOTE: do not add new entries to this table unless you have read
1590  * Documentation/sysctl/ctl_unnumbered.txt
1591  */
1592         { .ctl_name = 0 }
1593 };
1594
1595 static struct ctl_table debug_table[] = {
1596 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1597         {
1598                 .ctl_name       = CTL_UNNUMBERED,
1599                 .procname       = "exception-trace",
1600                 .data           = &show_unhandled_signals,
1601                 .maxlen         = sizeof(int),
1602                 .mode           = 0644,
1603                 .proc_handler   = proc_dointvec
1604         },
1605 #endif
1606         { .ctl_name = 0 }
1607 };
1608
1609 static struct ctl_table dev_table[] = {
1610         { .ctl_name = 0 }
1611 };
1612
1613 static DEFINE_SPINLOCK(sysctl_lock);
1614
1615 /* called under sysctl_lock */
1616 static int use_table(struct ctl_table_header *p)
1617 {
1618         if (unlikely(p->unregistering))
1619                 return 0;
1620         p->used++;
1621         return 1;
1622 }
1623
1624 /* called under sysctl_lock */
1625 static void unuse_table(struct ctl_table_header *p)
1626 {
1627         if (!--p->used)
1628                 if (unlikely(p->unregistering))
1629                         complete(p->unregistering);
1630 }
1631
1632 /* called under sysctl_lock, will reacquire if has to wait */
1633 static void start_unregistering(struct ctl_table_header *p)
1634 {
1635         /*
1636          * if p->used is 0, nobody will ever touch that entry again;
1637          * we'll eliminate all paths to it before dropping sysctl_lock
1638          */
1639         if (unlikely(p->used)) {
1640                 struct completion wait;
1641                 init_completion(&wait);
1642                 p->unregistering = &wait;
1643                 spin_unlock(&sysctl_lock);
1644                 wait_for_completion(&wait);
1645                 spin_lock(&sysctl_lock);
1646         } else {
1647                 /* anything non-NULL; we'll never dereference it */
1648                 p->unregistering = ERR_PTR(-EINVAL);
1649         }
1650         /*
1651          * do not remove from the list until nobody holds it; walking the
1652          * list in do_sysctl() relies on that.
1653          */
1654         list_del_init(&p->ctl_entry);
1655 }
1656
1657 void sysctl_head_get(struct ctl_table_header *head)
1658 {
1659         spin_lock(&sysctl_lock);
1660         head->count++;
1661         spin_unlock(&sysctl_lock);
1662 }
1663
1664 void sysctl_head_put(struct ctl_table_header *head)
1665 {
1666         spin_lock(&sysctl_lock);
1667         if (!--head->count)
1668                 kfree(head);
1669         spin_unlock(&sysctl_lock);
1670 }
1671
1672 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1673 {
1674         if (!head)
1675                 BUG();
1676         spin_lock(&sysctl_lock);
1677         if (!use_table(head))
1678                 head = ERR_PTR(-ENOENT);
1679         spin_unlock(&sysctl_lock);
1680         return head;
1681 }
1682
1683 void sysctl_head_finish(struct ctl_table_header *head)
1684 {
1685         if (!head)
1686                 return;
1687         spin_lock(&sysctl_lock);
1688         unuse_table(head);
1689         spin_unlock(&sysctl_lock);
1690 }
1691
1692 static struct ctl_table_set *
1693 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1694 {
1695         struct ctl_table_set *set = &root->default_set;
1696         if (root->lookup)
1697                 set = root->lookup(root, namespaces);
1698         return set;
1699 }
1700
1701 static struct list_head *
1702 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1703 {
1704         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1705         return &set->list;
1706 }
1707
1708 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1709                                             struct ctl_table_header *prev)
1710 {
1711         struct ctl_table_root *root;
1712         struct list_head *header_list;
1713         struct ctl_table_header *head;
1714         struct list_head *tmp;
1715
1716         spin_lock(&sysctl_lock);
1717         if (prev) {
1718                 head = prev;
1719                 tmp = &prev->ctl_entry;
1720                 unuse_table(prev);
1721                 goto next;
1722         }
1723         tmp = &root_table_header.ctl_entry;
1724         for (;;) {
1725                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1726
1727                 if (!use_table(head))
1728                         goto next;
1729                 spin_unlock(&sysctl_lock);
1730                 return head;
1731         next:
1732                 root = head->root;
1733                 tmp = tmp->next;
1734                 header_list = lookup_header_list(root, namespaces);
1735                 if (tmp != header_list)
1736                         continue;
1737
1738                 do {
1739                         root = list_entry(root->root_list.next,
1740                                         struct ctl_table_root, root_list);
1741                         if (root == &sysctl_table_root)
1742                                 goto out;
1743                         header_list = lookup_header_list(root, namespaces);
1744                 } while (list_empty(header_list));
1745                 tmp = header_list->next;
1746         }
1747 out:
1748         spin_unlock(&sysctl_lock);
1749         return NULL;
1750 }
1751
1752 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1753 {
1754         return __sysctl_head_next(current->nsproxy, prev);
1755 }
1756
1757 void register_sysctl_root(struct ctl_table_root *root)
1758 {
1759         spin_lock(&sysctl_lock);
1760         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1761         spin_unlock(&sysctl_lock);
1762 }
1763
1764 #ifdef CONFIG_SYSCTL_SYSCALL
1765 /* Perform the actual read/write of a sysctl table entry. */
1766 static int do_sysctl_strategy(struct ctl_table_root *root,
1767                         struct ctl_table *table,
1768                         void __user *oldval, size_t __user *oldlenp,
1769                         void __user *newval, size_t newlen)
1770 {
1771         int op = 0, rc;
1772
1773         if (oldval)
1774                 op |= MAY_READ;
1775         if (newval)
1776                 op |= MAY_WRITE;
1777         if (sysctl_perm(root, table, op))
1778                 return -EPERM;
1779
1780         if (table->strategy) {
1781                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1782                 if (rc < 0)
1783                         return rc;
1784                 if (rc > 0)
1785                         return 0;
1786         }
1787
1788         /* If there is no strategy routine, or if the strategy returns
1789          * zero, proceed with automatic r/w */
1790         if (table->data && table->maxlen) {
1791                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1792                 if (rc < 0)
1793                         return rc;
1794         }
1795         return 0;
1796 }
1797
1798 static int parse_table(int __user *name, int nlen,
1799                        void __user *oldval, size_t __user *oldlenp,
1800                        void __user *newval, size_t newlen,
1801                        struct ctl_table_root *root,
1802                        struct ctl_table *table)
1803 {
1804         int n;
1805 repeat:
1806         if (!nlen)
1807                 return -ENOTDIR;
1808         if (get_user(n, name))
1809                 return -EFAULT;
1810         for ( ; table->ctl_name || table->procname; table++) {
1811                 if (!table->ctl_name)
1812                         continue;
1813                 if (n == table->ctl_name) {
1814                         int error;
1815                         if (table->child) {
1816                                 if (sysctl_perm(root, table, MAY_EXEC))
1817                                         return -EPERM;
1818                                 name++;
1819                                 nlen--;
1820                                 table = table->child;
1821                                 goto repeat;
1822                         }
1823                         error = do_sysctl_strategy(root, table,
1824                                                    oldval, oldlenp,
1825                                                    newval, newlen);
1826                         return error;
1827                 }
1828         }
1829         return -ENOTDIR;
1830 }
1831
1832 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1833                void __user *newval, size_t newlen)
1834 {
1835         struct ctl_table_header *head;
1836         int error = -ENOTDIR;
1837
1838         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1839                 return -ENOTDIR;
1840         if (oldval) {
1841                 int old_len;
1842                 if (!oldlenp || get_user(old_len, oldlenp))
1843                         return -EFAULT;
1844         }
1845
1846         for (head = sysctl_head_next(NULL); head;
1847                         head = sysctl_head_next(head)) {
1848                 error = parse_table(name, nlen, oldval, oldlenp,
1849                                         newval, newlen,
1850                                         head->root, head->ctl_table);
1851                 if (error != -ENOTDIR) {
1852                         sysctl_head_finish(head);
1853                         break;
1854                 }
1855         }
1856         return error;
1857 }
1858
1859 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1860 {
1861         struct __sysctl_args tmp;
1862         int error;
1863
1864         if (copy_from_user(&tmp, args, sizeof(tmp)))
1865                 return -EFAULT;
1866
1867         error = deprecated_sysctl_warning(&tmp);
1868         if (error)
1869                 goto out;
1870
1871         lock_kernel();
1872         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1873                           tmp.newval, tmp.newlen);
1874         unlock_kernel();
1875 out:
1876         return error;
1877 }
1878 #endif /* CONFIG_SYSCTL_SYSCALL */
1879
1880 /*
1881  * sysctl_perm does NOT grant the superuser all rights automatically, because
1882  * some sysctl variables are readonly even to root.
1883  */
1884
1885 static int test_perm(int mode, int op)
1886 {
1887         if (!current_euid())
1888                 mode >>= 6;
1889         else if (in_egroup_p(0))
1890                 mode >>= 3;
1891         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1892                 return 0;
1893         return -EACCES;
1894 }
1895
1896 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1897 {
1898         int error;
1899         int mode;
1900
1901         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1902         if (error)
1903                 return error;
1904
1905         if (root->permissions)
1906                 mode = root->permissions(root, current->nsproxy, table);
1907         else
1908                 mode = table->mode;
1909
1910         return test_perm(mode, op);
1911 }
1912
1913 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1914 {
1915         for (; table->ctl_name || table->procname; table++) {
1916                 table->parent = parent;
1917                 if (table->child)
1918                         sysctl_set_parent(table, table->child);
1919         }
1920 }
1921
1922 static __init int sysctl_init(void)
1923 {
1924         sysctl_set_parent(NULL, root_table);
1925 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1926         {
1927                 int err;
1928                 err = sysctl_check_table(current->nsproxy, root_table);
1929         }
1930 #endif
1931         return 0;
1932 }
1933
1934 core_initcall(sysctl_init);
1935
1936 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1937                                       struct ctl_table *table)
1938 {
1939         struct ctl_table *p;
1940         const char *s = branch->procname;
1941
1942         /* branch should have named subdirectory as its first element */
1943         if (!s || !branch->child)
1944                 return NULL;
1945
1946         /* ... and nothing else */
1947         if (branch[1].procname || branch[1].ctl_name)
1948                 return NULL;
1949
1950         /* table should contain subdirectory with the same name */
1951         for (p = table; p->procname || p->ctl_name; p++) {
1952                 if (!p->child)
1953                         continue;
1954                 if (p->procname && strcmp(p->procname, s) == 0)
1955                         return p;
1956         }
1957         return NULL;
1958 }
1959
1960 /* see if attaching q to p would be an improvement */
1961 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1962 {
1963         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1964         struct ctl_table *next;
1965         int is_better = 0;
1966         int not_in_parent = !p->attached_by;
1967
1968         while ((next = is_branch_in(by, to)) != NULL) {
1969                 if (by == q->attached_by)
1970                         is_better = 1;
1971                 if (to == p->attached_by)
1972                         not_in_parent = 1;
1973                 by = by->child;
1974                 to = next->child;
1975         }
1976
1977         if (is_better && not_in_parent) {
1978                 q->attached_by = by;
1979                 q->attached_to = to;
1980                 q->parent = p;
1981         }
1982 }
1983
1984 /**
1985  * __register_sysctl_paths - register a sysctl hierarchy
1986  * @root: List of sysctl headers to register on
1987  * @namespaces: Data to compute which lists of sysctl entries are visible
1988  * @path: The path to the directory the sysctl table is in.
1989  * @table: the top-level table structure
1990  *
1991  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1992  * array. A completely 0 filled entry terminates the table.
1993  *
1994  * The members of the &struct ctl_table structure are used as follows:
1995  *
1996  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1997  *            must be unique within that level of sysctl
1998  *
1999  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
2000  *            enter a sysctl file
2001  *
2002  * data - a pointer to data for use by proc_handler
2003  *
2004  * maxlen - the maximum size in bytes of the data
2005  *
2006  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
2007  *
2008  * child - a pointer to the child sysctl table if this entry is a directory, or
2009  *         %NULL.
2010  *
2011  * proc_handler - the text handler routine (described below)
2012  *
2013  * strategy - the strategy routine (described below)
2014  *
2015  * de - for internal use by the sysctl routines
2016  *
2017  * extra1, extra2 - extra pointers usable by the proc handler routines
2018  *
2019  * Leaf nodes in the sysctl tree will be represented by a single file
2020  * under /proc; non-leaf nodes will be represented by directories.
2021  *
2022  * sysctl(2) can automatically manage read and write requests through
2023  * the sysctl table.  The data and maxlen fields of the ctl_table
2024  * struct enable minimal validation of the values being written to be
2025  * performed, and the mode field allows minimal authentication.
2026  *
2027  * More sophisticated management can be enabled by the provision of a
2028  * strategy routine with the table entry.  This will be called before
2029  * any automatic read or write of the data is performed.
2030  *
2031  * The strategy routine may return
2032  *
2033  * < 0 - Error occurred (error is passed to user process)
2034  *
2035  * 0   - OK - proceed with automatic read or write.
2036  *
2037  * > 0 - OK - read or write has been done by the strategy routine, so
2038  *       return immediately.
2039  *
2040  * There must be a proc_handler routine for any terminal nodes
2041  * mirrored under /proc/sys (non-terminals are handled by a built-in
2042  * directory handler).  Several default handlers are available to
2043  * cover common cases -
2044  *
2045  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
2046  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
2047  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
2048  *
2049  * It is the handler's job to read the input buffer from user memory
2050  * and process it. The handler should return 0 on success.
2051  *
2052  * This routine returns %NULL on a failure to register, and a pointer
2053  * to the table header on success.
2054  */
2055 struct ctl_table_header *__register_sysctl_paths(
2056         struct ctl_table_root *root,
2057         struct nsproxy *namespaces,
2058         const struct ctl_path *path, struct ctl_table *table)
2059 {
2060         struct ctl_table_header *header;
2061         struct ctl_table *new, **prevp;
2062         unsigned int n, npath;
2063         struct ctl_table_set *set;
2064
2065         /* Count the path components */
2066         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2067                 ;
2068
2069         /*
2070          * For each path component, allocate a 2-element ctl_table array.
2071          * The first array element will be filled with the sysctl entry
2072          * for this, the second will be the sentinel (ctl_name == 0).
2073          *
2074          * We allocate everything in one go so that we don't have to
2075          * worry about freeing additional memory in unregister_sysctl_table.
2076          */
2077         header = kzalloc(sizeof(struct ctl_table_header) +
2078                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2079         if (!header)
2080                 return NULL;
2081
2082         new = (struct ctl_table *) (header + 1);
2083
2084         /* Now connect the dots */
2085         prevp = &header->ctl_table;
2086         for (n = 0; n < npath; ++n, ++path) {
2087                 /* Copy the procname */
2088                 new->procname = path->procname;
2089                 new->ctl_name = path->ctl_name;
2090                 new->mode     = 0555;
2091
2092                 *prevp = new;
2093                 prevp = &new->child;
2094
2095                 new += 2;
2096         }
2097         *prevp = table;
2098         header->ctl_table_arg = table;
2099
2100         INIT_LIST_HEAD(&header->ctl_entry);
2101         header->used = 0;
2102         header->unregistering = NULL;
2103         header->root = root;
2104         sysctl_set_parent(NULL, header->ctl_table);
2105         header->count = 1;
2106 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2107         if (sysctl_check_table(namespaces, header->ctl_table)) {
2108                 kfree(header);
2109                 return NULL;
2110         }
2111 #endif
2112         spin_lock(&sysctl_lock);
2113         header->set = lookup_header_set(root, namespaces);
2114         header->attached_by = header->ctl_table;
2115         header->attached_to = root_table;
2116         header->parent = &root_table_header;
2117         for (set = header->set; set; set = set->parent) {
2118                 struct ctl_table_header *p;
2119                 list_for_each_entry(p, &set->list, ctl_entry) {
2120                         if (p->unregistering)
2121                                 continue;
2122                         try_attach(p, header);
2123                 }
2124         }
2125         header->parent->count++;
2126         list_add_tail(&header->ctl_entry, &header->set->list);
2127         spin_unlock(&sysctl_lock);
2128
2129         return header;
2130 }
2131
2132 /**
2133  * register_sysctl_table_path - register a sysctl table hierarchy
2134  * @path: The path to the directory the sysctl table is in.
2135  * @table: the top-level table structure
2136  *
2137  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2138  * array. A completely 0 filled entry terminates the table.
2139  *
2140  * See __register_sysctl_paths for more details.
2141  */
2142 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2143                                                 struct ctl_table *table)
2144 {
2145         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2146                                         path, table);
2147 }
2148
2149 /**
2150  * register_sysctl_table - register a sysctl table hierarchy
2151  * @table: the top-level table structure
2152  *
2153  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2154  * array. A completely 0 filled entry terminates the table.
2155  *
2156  * See register_sysctl_paths for more details.
2157  */
2158 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2159 {
2160         static const struct ctl_path null_path[] = { {} };
2161
2162         return register_sysctl_paths(null_path, table);
2163 }
2164
2165 /**
2166  * unregister_sysctl_table - unregister a sysctl table hierarchy
2167  * @header: the header returned from register_sysctl_table
2168  *
2169  * Unregisters the sysctl table and all children. proc entries may not
2170  * actually be removed until they are no longer used by anyone.
2171  */
2172 void unregister_sysctl_table(struct ctl_table_header * header)
2173 {
2174         might_sleep();
2175
2176         if (header == NULL)
2177                 return;
2178
2179         spin_lock(&sysctl_lock);
2180         start_unregistering(header);
2181         if (!--header->parent->count) {
2182                 WARN_ON(1);
2183                 kfree(header->parent);
2184         }
2185         if (!--header->count)
2186                 kfree(header);
2187         spin_unlock(&sysctl_lock);
2188 }
2189
2190 int sysctl_is_seen(struct ctl_table_header *p)
2191 {
2192         struct ctl_table_set *set = p->set;
2193         int res;
2194         spin_lock(&sysctl_lock);
2195         if (p->unregistering)
2196                 res = 0;
2197         else if (!set->is_seen)
2198                 res = 1;
2199         else
2200                 res = set->is_seen(set);
2201         spin_unlock(&sysctl_lock);
2202         return res;
2203 }
2204
2205 void setup_sysctl_set(struct ctl_table_set *p,
2206         struct ctl_table_set *parent,
2207         int (*is_seen)(struct ctl_table_set *))
2208 {
2209         INIT_LIST_HEAD(&p->list);
2210         p->parent = parent ? parent : &sysctl_table_root.default_set;
2211         p->is_seen = is_seen;
2212 }
2213
2214 #else /* !CONFIG_SYSCTL */
2215 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2216 {
2217         return NULL;
2218 }
2219
2220 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2221                                                     struct ctl_table *table)
2222 {
2223         return NULL;
2224 }
2225
2226 void unregister_sysctl_table(struct ctl_table_header * table)
2227 {
2228 }
2229
2230 void setup_sysctl_set(struct ctl_table_set *p,
2231         struct ctl_table_set *parent,
2232         int (*is_seen)(struct ctl_table_set *))
2233 {
2234 }
2235
2236 void sysctl_head_put(struct ctl_table_header *head)
2237 {
2238 }
2239
2240 #endif /* CONFIG_SYSCTL */
2241
2242 /*
2243  * /proc/sys support
2244  */
2245
2246 #ifdef CONFIG_PROC_SYSCTL
2247
2248 static int _proc_do_string(void* data, int maxlen, int write,
2249                            void __user *buffer,
2250                            size_t *lenp, loff_t *ppos)
2251 {
2252         size_t len;
2253         char __user *p;
2254         char c;
2255
2256         if (!data || !maxlen || !*lenp) {
2257                 *lenp = 0;
2258                 return 0;
2259         }
2260
2261         if (write) {
2262                 len = 0;
2263                 p = buffer;
2264                 while (len < *lenp) {
2265                         if (get_user(c, p++))
2266                                 return -EFAULT;
2267                         if (c == 0 || c == '\n')
2268                                 break;
2269                         len++;
2270                 }
2271                 if (len >= maxlen)
2272                         len = maxlen-1;
2273                 if(copy_from_user(data, buffer, len))
2274                         return -EFAULT;
2275                 ((char *) data)[len] = 0;
2276                 *ppos += *lenp;
2277         } else {
2278                 len = strlen(data);
2279                 if (len > maxlen)
2280                         len = maxlen;
2281
2282                 if (*ppos > len) {
2283                         *lenp = 0;
2284                         return 0;
2285                 }
2286
2287                 data += *ppos;
2288                 len  -= *ppos;
2289
2290                 if (len > *lenp)
2291                         len = *lenp;
2292                 if (len)
2293                         if(copy_to_user(buffer, data, len))
2294                                 return -EFAULT;
2295                 if (len < *lenp) {
2296                         if(put_user('\n', ((char __user *) buffer) + len))
2297                                 return -EFAULT;
2298                         len++;
2299                 }
2300                 *lenp = len;
2301                 *ppos += len;
2302         }
2303         return 0;
2304 }
2305
2306 /**
2307  * proc_dostring - read a string sysctl
2308  * @table: the sysctl table
2309  * @write: %TRUE if this is a write to the sysctl file
2310  * @buffer: the user buffer
2311  * @lenp: the size of the user buffer
2312  * @ppos: file position
2313  *
2314  * Reads/writes a string from/to the user buffer. If the kernel
2315  * buffer provided is not large enough to hold the string, the
2316  * string is truncated. The copied string is %NULL-terminated.
2317  * If the string is being read by the user process, it is copied
2318  * and a newline '\n' is added. It is truncated if the buffer is
2319  * not large enough.
2320  *
2321  * Returns 0 on success.
2322  */
2323 int proc_dostring(struct ctl_table *table, int write,
2324                   void __user *buffer, size_t *lenp, loff_t *ppos)
2325 {
2326         return _proc_do_string(table->data, table->maxlen, write,
2327                                buffer, lenp, ppos);
2328 }
2329
2330
2331 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2332                                  int *valp,
2333                                  int write, void *data)
2334 {
2335         if (write) {
2336                 *valp = *negp ? -*lvalp : *lvalp;
2337         } else {
2338                 int val = *valp;
2339                 if (val < 0) {
2340                         *negp = -1;
2341                         *lvalp = (unsigned long)-val;
2342                 } else {
2343                         *negp = 0;
2344                         *lvalp = (unsigned long)val;
2345                 }
2346         }
2347         return 0;
2348 }
2349
2350 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2351                   int write, void __user *buffer,
2352                   size_t *lenp, loff_t *ppos,
2353                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2354                               int write, void *data),
2355                   void *data)
2356 {
2357 #define TMPBUFLEN 21
2358         int *i, vleft, first = 1, neg;
2359         unsigned long lval;
2360         size_t left, len;
2361
2362         char buf[TMPBUFLEN], *p;
2363         char __user *s = buffer;
2364
2365         if (!tbl_data || !table->maxlen || !*lenp ||
2366             (*ppos && !write)) {
2367                 *lenp = 0;
2368                 return 0;
2369         }
2370
2371         i = (int *) tbl_data;
2372         vleft = table->maxlen / sizeof(*i);
2373         left = *lenp;
2374
2375         if (!conv)
2376                 conv = do_proc_dointvec_conv;
2377
2378         for (; left && vleft--; i++, first=0) {
2379                 if (write) {
2380                         while (left) {
2381                                 char c;
2382                                 if (get_user(c, s))
2383                                         return -EFAULT;
2384                                 if (!isspace(c))
2385                                         break;
2386                                 left--;
2387                                 s++;
2388                         }
2389                         if (!left)
2390                                 break;
2391                         neg = 0;
2392                         len = left;
2393                         if (len > sizeof(buf) - 1)
2394                                 len = sizeof(buf) - 1;
2395                         if (copy_from_user(buf, s, len))
2396                                 return -EFAULT;
2397                         buf[len] = 0;
2398                         p = buf;
2399                         if (*p == '-' && left > 1) {
2400                                 neg = 1;
2401                                 p++;
2402                         }
2403                         if (*p < '0' || *p > '9')
2404                                 break;
2405
2406                         lval = simple_strtoul(p, &p, 0);
2407
2408                         len = p-buf;
2409                         if ((len < left) && *p && !isspace(*p))
2410                                 break;
2411                         s += len;
2412                         left -= len;
2413
2414                         if (conv(&neg, &lval, i, 1, data))
2415                                 break;
2416                 } else {
2417                         p = buf;
2418                         if (!first)
2419                                 *p++ = '\t';
2420
2421                         if (conv(&neg, &lval, i, 0, data))
2422                                 break;
2423
2424                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2425                         len = strlen(buf);
2426                         if (len > left)
2427                                 len = left;
2428                         if(copy_to_user(s, buf, len))
2429                                 return -EFAULT;
2430                         left -= len;
2431                         s += len;
2432                 }
2433         }
2434
2435         if (!write && !first && left) {
2436                 if(put_user('\n', s))
2437                         return -EFAULT;
2438                 left--, s++;
2439         }
2440         if (write) {
2441                 while (left) {
2442                         char c;
2443                         if (get_user(c, s++))
2444                                 return -EFAULT;
2445                         if (!isspace(c))
2446                                 break;
2447                         left--;
2448                 }
2449         }
2450         if (write && first)
2451                 return -EINVAL;
2452         *lenp -= left;
2453         *ppos += *lenp;
2454         return 0;
2455 #undef TMPBUFLEN
2456 }
2457
2458 static int do_proc_dointvec(struct ctl_table *table, int write,
2459                   void __user *buffer, size_t *lenp, loff_t *ppos,
2460                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2461                               int write, void *data),
2462                   void *data)
2463 {
2464         return __do_proc_dointvec(table->data, table, write,
2465                         buffer, lenp, ppos, conv, data);
2466 }
2467
2468 /**
2469  * proc_dointvec - read a vector of integers
2470  * @table: the sysctl table
2471  * @write: %TRUE if this is a write to the sysctl file
2472  * @buffer: the user buffer
2473  * @lenp: the size of the user buffer
2474  * @ppos: file position
2475  *
2476  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2477  * values from/to the user buffer, treated as an ASCII string.
2478  *
2479  * Returns 0 on success.
2480  */
2481 int proc_dointvec(struct ctl_table *table, int write,
2482                      void __user *buffer, size_t *lenp, loff_t *ppos)
2483 {
2484     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2485                             NULL,NULL);
2486 }
2487
2488 /*
2489  * Taint values can only be increased
2490  * This means we can safely use a temporary.
2491  */
2492 static int proc_taint(struct ctl_table *table, int write,
2493                                void __user *buffer, size_t *lenp, loff_t *ppos)
2494 {
2495         struct ctl_table t;
2496         unsigned long tmptaint = get_taint();
2497         int err;
2498
2499         if (write && !capable(CAP_SYS_ADMIN))
2500                 return -EPERM;
2501
2502         t = *table;
2503         t.data = &tmptaint;
2504         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2505         if (err < 0)
2506                 return err;
2507
2508         if (write) {
2509                 /*
2510                  * Poor man's atomic or. Not worth adding a primitive
2511                  * to everyone's atomic.h for this
2512                  */
2513                 int i;
2514                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2515                         if ((tmptaint >> i) & 1)
2516                                 add_taint(i);
2517                 }
2518         }
2519
2520         return err;
2521 }
2522
2523 struct do_proc_dointvec_minmax_conv_param {
2524         int *min;
2525         int *max;
2526 };
2527
2528 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2529                                         int *valp,
2530                                         int write, void *data)
2531 {
2532         struct do_proc_dointvec_minmax_conv_param *param = data;
2533         if (write) {
2534                 int val = *negp ? -*lvalp : *lvalp;
2535                 if ((param->min && *param->min > val) ||
2536                     (param->max && *param->max < val))
2537                         return -EINVAL;
2538                 *valp = val;
2539         } else {
2540                 int val = *valp;
2541                 if (val < 0) {
2542                         *negp = -1;
2543                         *lvalp = (unsigned long)-val;
2544                 } else {
2545                         *negp = 0;
2546                         *lvalp = (unsigned long)val;
2547                 }
2548         }
2549         return 0;
2550 }
2551
2552 /**
2553  * proc_dointvec_minmax - read a vector of integers with min/max values
2554  * @table: the sysctl table
2555  * @write: %TRUE if this is a write to the sysctl file
2556  * @buffer: the user buffer
2557  * @lenp: the size of the user buffer
2558  * @ppos: file position
2559  *
2560  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2561  * values from/to the user buffer, treated as an ASCII string.
2562  *
2563  * This routine will ensure the values are within the range specified by
2564  * table->extra1 (min) and table->extra2 (max).
2565  *
2566  * Returns 0 on success.
2567  */
2568 int proc_dointvec_minmax(struct ctl_table *table, int write,
2569                   void __user *buffer, size_t *lenp, loff_t *ppos)
2570 {
2571         struct do_proc_dointvec_minmax_conv_param param = {
2572                 .min = (int *) table->extra1,
2573                 .max = (int *) table->extra2,
2574         };
2575         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2576                                 do_proc_dointvec_minmax_conv, &param);
2577 }
2578
2579 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2580                                      void __user *buffer,
2581                                      size_t *lenp, loff_t *ppos,
2582                                      unsigned long convmul,
2583                                      unsigned long convdiv)
2584 {
2585 #define TMPBUFLEN 21
2586         unsigned long *i, *min, *max, val;
2587         int vleft, first=1, neg;
2588         size_t len, left;
2589         char buf[TMPBUFLEN], *p;
2590         char __user *s = buffer;
2591
2592         if (!data || !table->maxlen || !*lenp ||
2593             (*ppos && !write)) {
2594                 *lenp = 0;
2595                 return 0;
2596         }
2597
2598         i = (unsigned long *) data;
2599         min = (unsigned long *) table->extra1;
2600         max = (unsigned long *) table->extra2;
2601         vleft = table->maxlen / sizeof(unsigned long);
2602         left = *lenp;
2603
2604         for (; left && vleft--; i++, min++, max++, first=0) {
2605                 if (write) {
2606                         while (left) {
2607                                 char c;
2608                                 if (get_user(c, s))
2609                                         return -EFAULT;
2610                                 if (!isspace(c))
2611                                         break;
2612                                 left--;
2613                                 s++;
2614                         }
2615                         if (!left)
2616                                 break;
2617                         neg = 0;
2618                         len = left;
2619                         if (len > TMPBUFLEN-1)
2620                                 len = TMPBUFLEN-1;
2621                         if (copy_from_user(buf, s, len))
2622                                 return -EFAULT;
2623                         buf[len] = 0;
2624                         p = buf;
2625                         if (*p == '-' && left > 1) {
2626                                 neg = 1;
2627                                 p++;
2628                         }
2629                         if (*p < '0' || *p > '9')
2630                                 break;
2631                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2632                         len = p-buf;
2633                         if ((len < left) && *p && !isspace(*p))
2634                                 break;
2635                         if (neg)
2636                                 val = -val;
2637                         s += len;
2638                         left -= len;
2639
2640                         if(neg)
2641                                 continue;
2642                         if ((min && val < *min) || (max && val > *max))
2643                                 continue;
2644                         *i = val;
2645                 } else {
2646                         p = buf;
2647                         if (!first)
2648                                 *p++ = '\t';
2649                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2650                         len = strlen(buf);
2651                         if (len > left)
2652                                 len = left;
2653                         if(copy_to_user(s, buf, len))
2654                                 return -EFAULT;
2655                         left -= len;
2656                         s += len;
2657                 }
2658         }
2659
2660         if (!write && !first && left) {
2661                 if(put_user('\n', s))
2662                         return -EFAULT;
2663                 left--, s++;
2664         }
2665         if (write) {
2666                 while (left) {
2667                         char c;
2668                         if (get_user(c, s++))
2669                                 return -EFAULT;
2670                         if (!isspace(c))
2671                                 break;
2672                         left--;
2673                 }
2674         }
2675         if (write && first)
2676                 return -EINVAL;
2677         *lenp -= left;
2678         *ppos += *lenp;
2679         return 0;
2680 #undef TMPBUFLEN
2681 }
2682
2683 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2684                                      void __user *buffer,
2685                                      size_t *lenp, loff_t *ppos,
2686                                      unsigned long convmul,
2687                                      unsigned long convdiv)
2688 {
2689         return __do_proc_doulongvec_minmax(table->data, table, write,
2690                         buffer, lenp, ppos, convmul, convdiv);
2691 }
2692
2693 /**
2694  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2695  * @table: the sysctl table
2696  * @write: %TRUE if this is a write to the sysctl file
2697  * @buffer: the user buffer
2698  * @lenp: the size of the user buffer
2699  * @ppos: file position
2700  *
2701  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2702  * values from/to the user buffer, treated as an ASCII string.
2703  *
2704  * This routine will ensure the values are within the range specified by
2705  * table->extra1 (min) and table->extra2 (max).
2706  *
2707  * Returns 0 on success.
2708  */
2709 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2710                            void __user *buffer, size_t *lenp, loff_t *ppos)
2711 {
2712     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2713 }
2714
2715 /**
2716  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2717  * @table: the sysctl table
2718  * @write: %TRUE if this is a write to the sysctl file
2719  * @buffer: the user buffer
2720  * @lenp: the size of the user buffer
2721  * @ppos: file position
2722  *
2723  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2724  * values from/to the user buffer, treated as an ASCII string. The values
2725  * are treated as milliseconds, and converted to jiffies when they are stored.
2726  *
2727  * This routine will ensure the values are within the range specified by
2728  * table->extra1 (min) and table->extra2 (max).
2729  *
2730  * Returns 0 on success.
2731  */
2732 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2733                                       void __user *buffer,
2734                                       size_t *lenp, loff_t *ppos)
2735 {
2736     return do_proc_doulongvec_minmax(table, write, buffer,
2737                                      lenp, ppos, HZ, 1000l);
2738 }
2739
2740
2741 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2742                                          int *valp,
2743                                          int write, void *data)
2744 {
2745         if (write) {
2746                 if (*lvalp > LONG_MAX / HZ)
2747                         return 1;
2748                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2749         } else {
2750                 int val = *valp;
2751                 unsigned long lval;
2752                 if (val < 0) {
2753                         *negp = -1;
2754                         lval = (unsigned long)-val;
2755                 } else {
2756                         *negp = 0;
2757                         lval = (unsigned long)val;
2758                 }
2759                 *lvalp = lval / HZ;
2760         }
2761         return 0;
2762 }
2763
2764 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2765                                                 int *valp,
2766                                                 int write, void *data)
2767 {
2768         if (write) {
2769                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2770                         return 1;
2771                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2772         } else {
2773                 int val = *valp;
2774                 unsigned long lval;
2775                 if (val < 0) {
2776                         *negp = -1;
2777                         lval = (unsigned long)-val;
2778                 } else {
2779                         *negp = 0;
2780                         lval = (unsigned long)val;
2781                 }
2782                 *lvalp = jiffies_to_clock_t(lval);
2783         }
2784         return 0;
2785 }
2786
2787 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2788                                             int *valp,
2789                                             int write, void *data)
2790 {
2791         if (write) {
2792                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2793         } else {
2794                 int val = *valp;
2795                 unsigned long lval;
2796                 if (val < 0) {
2797                         *negp = -1;
2798                         lval = (unsigned long)-val;
2799                 } else {
2800                         *negp = 0;
2801                         lval = (unsigned long)val;
2802                 }
2803                 *lvalp = jiffies_to_msecs(lval);
2804         }
2805         return 0;
2806 }
2807
2808 /**
2809  * proc_dointvec_jiffies - read a vector of integers as seconds
2810  * @table: the sysctl table
2811  * @write: %TRUE if this is a write to the sysctl file
2812  * @buffer: the user buffer
2813  * @lenp: the size of the user buffer
2814  * @ppos: file position
2815  *
2816  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2817  * values from/to the user buffer, treated as an ASCII string.
2818  * The values read are assumed to be in seconds, and are converted into
2819  * jiffies.
2820  *
2821  * Returns 0 on success.
2822  */
2823 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2824                           void __user *buffer, size_t *lenp, loff_t *ppos)
2825 {
2826     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2827                             do_proc_dointvec_jiffies_conv,NULL);
2828 }
2829
2830 /**
2831  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2832  * @table: the sysctl table
2833  * @write: %TRUE if this is a write to the sysctl file
2834  * @buffer: the user buffer
2835  * @lenp: the size of the user buffer
2836  * @ppos: pointer to the file position
2837  *
2838  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2839  * values from/to the user buffer, treated as an ASCII string.
2840  * The values read are assumed to be in 1/USER_HZ seconds, and
2841  * are converted into jiffies.
2842  *
2843  * Returns 0 on success.
2844  */
2845 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2846                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2847 {
2848     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2849                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2850 }
2851
2852 /**
2853  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2854  * @table: the sysctl table
2855  * @write: %TRUE if this is a write to the sysctl file
2856  * @buffer: the user buffer
2857  * @lenp: the size of the user buffer
2858  * @ppos: file position
2859  * @ppos: the current position in the file
2860  *
2861  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2862  * values from/to the user buffer, treated as an ASCII string.
2863  * The values read are assumed to be in 1/1000 seconds, and
2864  * are converted into jiffies.
2865  *
2866  * Returns 0 on success.
2867  */
2868 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2869                              void __user *buffer, size_t *lenp, loff_t *ppos)
2870 {
2871         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2872                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2873 }
2874
2875 static int proc_do_cad_pid(struct ctl_table *table, int write,
2876                            void __user *buffer, size_t *lenp, loff_t *ppos)
2877 {
2878         struct pid *new_pid;
2879         pid_t tmp;
2880         int r;
2881
2882         tmp = pid_vnr(cad_pid);
2883
2884         r = __do_proc_dointvec(&tmp, table, write, buffer,
2885                                lenp, ppos, NULL, NULL);
2886         if (r || !write)
2887                 return r;
2888
2889         new_pid = find_get_pid(tmp);
2890         if (!new_pid)
2891                 return -ESRCH;
2892
2893         put_pid(xchg(&cad_pid, new_pid));
2894         return 0;
2895 }
2896
2897 #else /* CONFIG_PROC_FS */
2898
2899 int proc_dostring(struct ctl_table *table, int write,
2900                   void __user *buffer, size_t *lenp, loff_t *ppos)
2901 {
2902         return -ENOSYS;
2903 }
2904
2905 int proc_dointvec(struct ctl_table *table, int write,
2906                   void __user *buffer, size_t *lenp, loff_t *ppos)
2907 {
2908         return -ENOSYS;
2909 }
2910
2911 int proc_dointvec_minmax(struct ctl_table *table, int write,
2912                     void __user *buffer, size_t *lenp, loff_t *ppos)
2913 {
2914         return -ENOSYS;
2915 }
2916
2917 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2918                     void __user *buffer, size_t *lenp, loff_t *ppos)
2919 {
2920         return -ENOSYS;
2921 }
2922
2923 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2924                     void __user *buffer, size_t *lenp, loff_t *ppos)
2925 {
2926         return -ENOSYS;
2927 }
2928
2929 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2930                              void __user *buffer, size_t *lenp, loff_t *ppos)
2931 {
2932         return -ENOSYS;
2933 }
2934
2935 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2936                     void __user *buffer, size_t *lenp, loff_t *ppos)
2937 {
2938         return -ENOSYS;
2939 }
2940
2941 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2942                                       void __user *buffer,
2943                                       size_t *lenp, loff_t *ppos)
2944 {
2945     return -ENOSYS;
2946 }
2947
2948
2949 #endif /* CONFIG_PROC_FS */
2950
2951
2952 #ifdef CONFIG_SYSCTL_SYSCALL
2953 /*
2954  * General sysctl support routines
2955  */
2956
2957 /* The generic sysctl data routine (used if no strategy routine supplied) */
2958 int sysctl_data(struct ctl_table *table,
2959                 void __user *oldval, size_t __user *oldlenp,
2960                 void __user *newval, size_t newlen)
2961 {
2962         size_t len;
2963
2964         /* Get out of I don't have a variable */
2965         if (!table->data || !table->maxlen)
2966                 return -ENOTDIR;
2967
2968         if (oldval && oldlenp) {
2969                 if (get_user(len, oldlenp))
2970                         return -EFAULT;
2971                 if (len) {
2972                         if (len > table->maxlen)
2973                                 len = table->maxlen;
2974                         if (copy_to_user(oldval, table->data, len))
2975                                 return -EFAULT;
2976                         if (put_user(len, oldlenp))
2977                                 return -EFAULT;
2978                 }
2979         }
2980
2981         if (newval && newlen) {
2982                 if (newlen > table->maxlen)
2983                         newlen = table->maxlen;
2984
2985                 if (copy_from_user(table->data, newval, newlen))
2986                         return -EFAULT;
2987         }
2988         return 1;
2989 }
2990
2991 /* The generic string strategy routine: */
2992 int sysctl_string(struct ctl_table *table,
2993                   void __user *oldval, size_t __user *oldlenp,
2994                   void __user *newval, size_t newlen)
2995 {
2996         if (!table->data || !table->maxlen)
2997                 return -ENOTDIR;
2998
2999         if (oldval && oldlenp) {
3000                 size_t bufsize;
3001                 if (get_user(bufsize, oldlenp))
3002                         return -EFAULT;
3003                 if (bufsize) {
3004                         size_t len = strlen(table->data), copied;
3005
3006                         /* This shouldn't trigger for a well-formed sysctl */
3007                         if (len > table->maxlen)
3008                                 len = table->maxlen;
3009
3010                         /* Copy up to a max of bufsize-1 bytes of the string */
3011                         copied = (len >= bufsize) ? bufsize - 1 : len;
3012
3013                         if (copy_to_user(oldval, table->data, copied) ||
3014                             put_user(0, (char __user *)(oldval + copied)))
3015                                 return -EFAULT;
3016                         if (put_user(len, oldlenp))
3017                                 return -EFAULT;
3018                 }
3019         }
3020         if (newval && newlen) {
3021                 size_t len = newlen;
3022                 if (len > table->maxlen)
3023                         len = table->maxlen;
3024                 if(copy_from_user(table->data, newval, len))
3025                         return -EFAULT;
3026                 if (len == table->maxlen)
3027                         len--;
3028                 ((char *) table->data)[len] = 0;
3029         }
3030         return 1;
3031 }
3032
3033 /*
3034  * This function makes sure that all of the integers in the vector
3035  * are between the minimum and maximum values given in the arrays
3036  * table->extra1 and table->extra2, respectively.
3037  */
3038 int sysctl_intvec(struct ctl_table *table,
3039                 void __user *oldval, size_t __user *oldlenp,
3040                 void __user *newval, size_t newlen)
3041 {
3042
3043         if (newval && newlen) {
3044                 int __user *vec = (int __user *) newval;
3045                 int *min = (int *) table->extra1;
3046                 int *max = (int *) table->extra2;
3047                 size_t length;
3048                 int i;
3049
3050                 if (newlen % sizeof(int) != 0)
3051                         return -EINVAL;
3052
3053                 if (!table->extra1 && !table->extra2)
3054                         return 0;
3055
3056                 if (newlen > table->maxlen)
3057                         newlen = table->maxlen;
3058                 length = newlen / sizeof(int);
3059
3060                 for (i = 0; i < length; i++) {
3061                         int value;
3062                         if (get_user(value, vec + i))
3063                                 return -EFAULT;
3064                         if (min && value < min[i])
3065                                 return -EINVAL;
3066                         if (max && value > max[i])
3067                                 return -EINVAL;
3068                 }
3069         }
3070         return 0;
3071 }
3072
3073 /* Strategy function to convert jiffies to seconds */
3074 int sysctl_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 = *(int *)(table->data) / HZ;
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) = new*HZ;
3103         }
3104         return 1;
3105 }
3106
3107 /* Strategy function to convert jiffies to seconds */
3108 int sysctl_ms_jiffies(struct ctl_table *table,
3109                 void __user *oldval, size_t __user *oldlenp,
3110                 void __user *newval, size_t newlen)
3111 {
3112         if (oldval && oldlenp) {
3113                 size_t olen;
3114
3115                 if (get_user(olen, oldlenp))
3116                         return -EFAULT;
3117                 if (olen) {
3118                         int val;
3119
3120                         if (olen < sizeof(int))
3121                                 return -EINVAL;
3122
3123                         val = jiffies_to_msecs(*(int *)(table->data));
3124                         if (put_user(val, (int __user *)oldval))
3125                                 return -EFAULT;
3126                         if (put_user(sizeof(int), oldlenp))
3127                                 return -EFAULT;
3128                 }
3129         }
3130         if (newval && newlen) {
3131                 int new;
3132                 if (newlen != sizeof(int))
3133                         return -EINVAL;
3134                 if (get_user(new, (int __user *)newval))
3135                         return -EFAULT;
3136                 *(int *)(table->data) = msecs_to_jiffies(new);
3137         }
3138         return 1;
3139 }
3140
3141
3142
3143 #else /* CONFIG_SYSCTL_SYSCALL */
3144
3145
3146 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3147 {
3148         struct __sysctl_args tmp;
3149         int error;
3150
3151         if (copy_from_user(&tmp, args, sizeof(tmp)))
3152                 return -EFAULT;
3153
3154         error = deprecated_sysctl_warning(&tmp);
3155
3156         /* If no error reading the parameters then just -ENOSYS ... */
3157         if (!error)
3158                 error = -ENOSYS;
3159
3160         return error;
3161 }
3162
3163 int sysctl_data(struct ctl_table *table,
3164                   void __user *oldval, size_t __user *oldlenp,
3165                   void __user *newval, size_t newlen)
3166 {
3167         return -ENOSYS;
3168 }
3169
3170 int sysctl_string(struct ctl_table *table,
3171                   void __user *oldval, size_t __user *oldlenp,
3172                   void __user *newval, size_t newlen)
3173 {
3174         return -ENOSYS;
3175 }
3176
3177 int sysctl_intvec(struct ctl_table *table,
3178                 void __user *oldval, size_t __user *oldlenp,
3179                 void __user *newval, size_t newlen)
3180 {
3181         return -ENOSYS;
3182 }
3183
3184 int sysctl_jiffies(struct ctl_table *table,
3185                 void __user *oldval, size_t __user *oldlenp,
3186                 void __user *newval, size_t newlen)
3187 {
3188         return -ENOSYS;
3189 }
3190
3191 int sysctl_ms_jiffies(struct ctl_table *table,
3192                 void __user *oldval, size_t __user *oldlenp,
3193                 void __user *newval, size_t newlen)
3194 {
3195         return -ENOSYS;
3196 }
3197
3198 #endif /* CONFIG_SYSCTL_SYSCALL */
3199
3200 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3201 {
3202         static int msg_count;
3203         int name[CTL_MAXNAME];
3204         int i;
3205
3206         /* Check args->nlen. */
3207         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3208                 return -ENOTDIR;
3209
3210         /* Read in the sysctl name for better debug message logging */
3211         for (i = 0; i < args->nlen; i++)
3212                 if (get_user(name[i], args->name + i))
3213                         return -EFAULT;
3214
3215         /* Ignore accesses to kernel.version */
3216         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3217                 return 0;
3218
3219         if (msg_count < 5) {
3220                 msg_count++;
3221                 printk(KERN_INFO
3222                         "warning: process `%s' used the deprecated sysctl "
3223                         "system call with ", current->comm);
3224                 for (i = 0; i < args->nlen; i++)
3225                         printk("%d.", name[i]);
3226                 printk("\n");
3227         }
3228         return 0;
3229 }
3230
3231 /*
3232  * No sense putting this after each symbol definition, twice,
3233  * exception granted :-)
3234  */
3235 EXPORT_SYMBOL(proc_dointvec);
3236 EXPORT_SYMBOL(proc_dointvec_jiffies);
3237 EXPORT_SYMBOL(proc_dointvec_minmax);
3238 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3239 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3240 EXPORT_SYMBOL(proc_dostring);
3241 EXPORT_SYMBOL(proc_doulongvec_minmax);
3242 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3243 EXPORT_SYMBOL(register_sysctl_table);
3244 EXPORT_SYMBOL(register_sysctl_paths);
3245 EXPORT_SYMBOL(sysctl_intvec);
3246 EXPORT_SYMBOL(sysctl_jiffies);
3247 EXPORT_SYMBOL(sysctl_ms_jiffies);
3248 EXPORT_SYMBOL(sysctl_string);
3249 EXPORT_SYMBOL(sysctl_data);
3250 EXPORT_SYMBOL(unregister_sysctl_table);