git.oblomov.eu Git - linux-2.6/blob - kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/kmemcheck.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_counter.h>
  54
  55 #include <asm/uaccess.h>
  56 #include <asm/processor.h>
  57
  58 #ifdef CONFIG_X86
  59 #include <asm/nmi.h>
  60 #include <asm/stacktrace.h>
  61 #include <asm/io.h>
  62 #endif
  63
  64 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  65
  66 #if defined(CONFIG_SYSCTL)
  67
  68 /* External variables not in a header file. */
  69 extern int C_A_D;
  70 extern int print_fatal_signals;
  71 extern int sysctl_overcommit_memory;
  72 extern int sysctl_overcommit_ratio;
  73 extern int sysctl_panic_on_oom;
  74 extern int sysctl_oom_kill_allocating_task;
  75 extern int sysctl_oom_dump_tasks;
  76 extern int max_threads;
  77 extern int core_uses_pid;
  78 extern int suid_dumpable;
  79 extern char core_pattern[];
  80 extern int pid_max;
  81 extern int min_free_kbytes;
  82 extern int pid_max_min, pid_max_max;
  83 extern int sysctl_drop_caches;
  84 extern int percpu_pagelist_fraction;
  85 extern int compat_log;
  86 extern int latencytop_enabled;
  87 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  88 #ifndef CONFIG_MMU
  89 extern int sysctl_nr_trim_pages;
  90 #endif
  91 #ifdef CONFIG_RCU_TORTURE_TEST
  92 extern int rcutorture_runnable;
  93 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  94
  95 /* Constants used for minimum and  maximum */
  96 #ifdef CONFIG_DETECT_SOFTLOCKUP
  97 static int sixty = 60;
  98 static int neg_one = -1;
  99 #endif
 100
 101 static int zero;
 102 static int __maybe_unused one = 1;
 103 static int __maybe_unused two = 2;
 104 static unsigned long one_ul = 1;
 105 static int one_hundred = 100;
 106
 107 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 108 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 109
 110 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 111 static int maxolduid = 65535;
 112 static int minolduid;
 113 static int min_percpu_pagelist_fract = 8;
 114
 115 static int ngroups_max = NGROUPS_MAX;
 116
 117 #ifdef CONFIG_MODULES
 118 extern char modprobe_path[];
 119 extern int modules_disabled;
 120 #endif
 121 #ifdef CONFIG_CHR_DEV_SG
 122 extern int sg_big_buff;
 123 #endif
 124
 125 #ifdef CONFIG_SPARC
 126 #include <asm/system.h>
 127 #endif
 128
 129 #ifdef CONFIG_SPARC64
 130 extern int sysctl_tsb_ratio;
 131 #endif
 132
 133 #ifdef __hppa__
 134 extern int pwrsw_enabled;
 135 extern int unaligned_enabled;
 136 #endif
 137
 138 #ifdef CONFIG_S390
 139 #ifdef CONFIG_MATHEMU
 140 extern int sysctl_ieee_emulation_warnings;
 141 #endif
 142 extern int sysctl_userprocess_debug;
 143 extern int spin_retry;
 144 #endif
 145
 146 #ifdef CONFIG_BSD_PROCESS_ACCT
 147 extern int acct_parm[];
 148 #endif
 149
 150 #ifdef CONFIG_IA64
 151 extern int no_unaligned_warning;
 152 extern int unaligned_dump_stack;
 153 #endif
 154
 155 #ifdef CONFIG_RT_MUTEXES
 156 extern int max_lock_depth;
 157 #endif
 158
 159 #ifdef CONFIG_PROC_SYSCTL
 160 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 161                   void __user *buffer, size_t *lenp, loff_t *ppos);
 162 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 163                                void __user *buffer, size_t *lenp, loff_t *ppos);
 164 #endif
 165
 166 static struct ctl_table root_table[];
 167 static struct ctl_table_root sysctl_table_root;
 168 static struct ctl_table_header root_table_header = {
 169         .count = 1,
 170         .ctl_table = root_table,
 171         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 172         .root = &sysctl_table_root,
 173         .set = &sysctl_table_root.default_set,
 174 };
 175 static struct ctl_table_root sysctl_table_root = {
 176         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 177         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 178 };
 179
 180 static struct ctl_table kern_table[];
 181 static struct ctl_table vm_table[];
 182 static struct ctl_table fs_table[];
 183 static struct ctl_table debug_table[];
 184 static struct ctl_table dev_table[];
 185 extern struct ctl_table random_table[];
 186 #ifdef CONFIG_INOTIFY_USER
 187 extern struct ctl_table inotify_table[];
 188 #endif
 189 #ifdef CONFIG_EPOLL
 190 extern struct ctl_table epoll_table[];
 191 #endif
 192
 193 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 194 int sysctl_legacy_va_layout;
 195 #endif
 196
 197 extern int prove_locking;
 198 extern int lock_stat;
 199
 200 /* The default sysctl tables: */
 201
 202 static struct ctl_table root_table[] = {
 203         {
 204                 .ctl_name       = CTL_KERN,
 205                 .procname       = "kernel",
 206                 .mode           = 0555,
 207                 .child          = kern_table,
 208         },
 209         {
 210                 .ctl_name       = CTL_VM,
 211                 .procname       = "vm",
 212                 .mode           = 0555,
 213                 .child          = vm_table,
 214         },
 215         {
 216                 .ctl_name       = CTL_FS,
 217                 .procname       = "fs",
 218                 .mode           = 0555,
 219                 .child          = fs_table,
 220         },
 221         {
 222                 .ctl_name       = CTL_DEBUG,
 223                 .procname       = "debug",
 224                 .mode           = 0555,
 225                 .child          = debug_table,
 226         },
 227         {
 228                 .ctl_name       = CTL_DEV,
 229                 .procname       = "dev",
 230                 .mode           = 0555,
 231                 .child          = dev_table,
 232         },
 233 /*
 234  * NOTE: do not add new entries to this table unless you have read
 235  * Documentation/sysctl/ctl_unnumbered.txt
 236  */
 237         { .ctl_name = 0 }
 238 };
 239
 240 #ifdef CONFIG_SCHED_DEBUG
 241 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 242 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 243 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 244 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 245 #endif
 246
 247 static struct ctl_table kern_table[] = {
 248 #ifdef CONFIG_SCHED_DEBUG
 249         {
 250                 .ctl_name       = CTL_UNNUMBERED,
 251                 .procname       = "sched_min_granularity_ns",
 252                 .data           = &sysctl_sched_min_granularity,
 253                 .maxlen         = sizeof(unsigned int),
 254                 .mode           = 0644,
 255                 .proc_handler   = &sched_nr_latency_handler,
 256                 .strategy       = &sysctl_intvec,
 257                 .extra1         = &min_sched_granularity_ns,
 258                 .extra2         = &max_sched_granularity_ns,
 259         },
 260         {
 261                 .ctl_name       = CTL_UNNUMBERED,
 262                 .procname       = "sched_latency_ns",
 263                 .data           = &sysctl_sched_latency,
 264                 .maxlen         = sizeof(unsigned int),
 265                 .mode           = 0644,
 266                 .proc_handler   = &sched_nr_latency_handler,
 267                 .strategy       = &sysctl_intvec,
 268                 .extra1         = &min_sched_granularity_ns,
 269                 .extra2         = &max_sched_granularity_ns,
 270         },
 271         {
 272                 .ctl_name       = CTL_UNNUMBERED,
 273                 .procname       = "sched_wakeup_granularity_ns",
 274                 .data           = &sysctl_sched_wakeup_granularity,
 275                 .maxlen         = sizeof(unsigned int),
 276                 .mode           = 0644,
 277                 .proc_handler   = &proc_dointvec_minmax,
 278                 .strategy       = &sysctl_intvec,
 279                 .extra1         = &min_wakeup_granularity_ns,
 280                 .extra2         = &max_wakeup_granularity_ns,
 281         },
 282         {
 283                 .ctl_name       = CTL_UNNUMBERED,
 284                 .procname       = "sched_shares_ratelimit",
 285                 .data           = &sysctl_sched_shares_ratelimit,
 286                 .maxlen         = sizeof(unsigned int),
 287                 .mode           = 0644,
 288                 .proc_handler   = &proc_dointvec,
 289         },
 290         {
 291                 .ctl_name       = CTL_UNNUMBERED,
 292                 .procname       = "sched_shares_thresh",
 293                 .data           = &sysctl_sched_shares_thresh,
 294                 .maxlen         = sizeof(unsigned int),
 295                 .mode           = 0644,
 296                 .proc_handler   = &proc_dointvec_minmax,
 297                 .strategy       = &sysctl_intvec,
 298                 .extra1         = &zero,
 299         },
 300         {
 301                 .ctl_name       = CTL_UNNUMBERED,
 302                 .procname       = "sched_child_runs_first",
 303                 .data           = &sysctl_sched_child_runs_first,
 304                 .maxlen         = sizeof(unsigned int),
 305                 .mode           = 0644,
 306                 .proc_handler   = &proc_dointvec,
 307         },
 308         {
 309                 .ctl_name       = CTL_UNNUMBERED,
 310                 .procname       = "sched_features",
 311                 .data           = &sysctl_sched_features,
 312                 .maxlen         = sizeof(unsigned int),
 313                 .mode           = 0644,
 314                 .proc_handler   = &proc_dointvec,
 315         },
 316         {
 317                 .ctl_name       = CTL_UNNUMBERED,
 318                 .procname       = "sched_migration_cost",
 319                 .data           = &sysctl_sched_migration_cost,
 320                 .maxlen         = sizeof(unsigned int),
 321                 .mode           = 0644,
 322                 .proc_handler   = &proc_dointvec,
 323         },
 324         {
 325                 .ctl_name       = CTL_UNNUMBERED,
 326                 .procname       = "sched_nr_migrate",
 327                 .data           = &sysctl_sched_nr_migrate,
 328                 .maxlen         = sizeof(unsigned int),
 329                 .mode           = 0644,
 330                 .proc_handler   = &proc_dointvec,
 331         },
 332 #endif
 333         {
 334                 .ctl_name       = CTL_UNNUMBERED,
 335                 .procname       = "sched_rt_period_us",
 336                 .data           = &sysctl_sched_rt_period,
 337                 .maxlen         = sizeof(unsigned int),
 338                 .mode           = 0644,
 339                 .proc_handler   = &sched_rt_handler,
 340         },
 341         {
 342                 .ctl_name       = CTL_UNNUMBERED,
 343                 .procname       = "sched_rt_runtime_us",
 344                 .data           = &sysctl_sched_rt_runtime,
 345                 .maxlen         = sizeof(int),
 346                 .mode           = 0644,
 347                 .proc_handler   = &sched_rt_handler,
 348         },
 349         {
 350                 .ctl_name       = CTL_UNNUMBERED,
 351                 .procname       = "sched_compat_yield",
 352                 .data           = &sysctl_sched_compat_yield,
 353                 .maxlen         = sizeof(unsigned int),
 354                 .mode           = 0644,
 355                 .proc_handler   = &proc_dointvec,
 356         },
 357 #ifdef CONFIG_PROVE_LOCKING
 358         {
 359                 .ctl_name       = CTL_UNNUMBERED,
 360                 .procname       = "prove_locking",
 361                 .data           = &prove_locking,
 362                 .maxlen         = sizeof(int),
 363                 .mode           = 0644,
 364                 .proc_handler   = &proc_dointvec,
 365         },
 366 #endif
 367 #ifdef CONFIG_LOCK_STAT
 368         {
 369                 .ctl_name       = CTL_UNNUMBERED,
 370                 .procname       = "lock_stat",
 371                 .data           = &lock_stat,
 372                 .maxlen         = sizeof(int),
 373                 .mode           = 0644,
 374                 .proc_handler   = &proc_dointvec,
 375         },
 376 #endif
 377         {
 378                 .ctl_name       = KERN_PANIC,
 379                 .procname       = "panic",
 380                 .data           = &panic_timeout,
 381                 .maxlen         = sizeof(int),
 382                 .mode           = 0644,
 383                 .proc_handler   = &proc_dointvec,
 384         },
 385         {
 386                 .ctl_name       = KERN_CORE_USES_PID,
 387                 .procname       = "core_uses_pid",
 388                 .data           = &core_uses_pid,
 389                 .maxlen         = sizeof(int),
 390                 .mode           = 0644,
 391                 .proc_handler   = &proc_dointvec,
 392         },
 393         {
 394                 .ctl_name       = KERN_CORE_PATTERN,
 395                 .procname       = "core_pattern",
 396                 .data           = core_pattern,
 397                 .maxlen         = CORENAME_MAX_SIZE,
 398                 .mode           = 0644,
 399                 .proc_handler   = &proc_dostring,
 400                 .strategy       = &sysctl_string,
 401         },
 402 #ifdef CONFIG_PROC_SYSCTL
 403         {
 404                 .procname       = "tainted",
 405                 .maxlen         = sizeof(long),
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_taint,
 408         },
 409 #endif
 410 #ifdef CONFIG_LATENCYTOP
 411         {
 412                 .procname       = "latencytop",
 413                 .data           = &latencytop_enabled,
 414                 .maxlen         = sizeof(int),
 415                 .mode           = 0644,
 416                 .proc_handler   = &proc_dointvec,
 417         },
 418 #endif
 419 #ifdef CONFIG_BLK_DEV_INITRD
 420         {
 421                 .ctl_name       = KERN_REALROOTDEV,
 422                 .procname       = "real-root-dev",
 423                 .data           = &real_root_dev,
 424                 .maxlen         = sizeof(int),
 425                 .mode           = 0644,
 426                 .proc_handler   = &proc_dointvec,
 427         },
 428 #endif
 429         {
 430                 .ctl_name       = CTL_UNNUMBERED,
 431                 .procname       = "print-fatal-signals",
 432                 .data           = &print_fatal_signals,
 433                 .maxlen         = sizeof(int),
 434                 .mode           = 0644,
 435                 .proc_handler   = &proc_dointvec,
 436         },
 437 #ifdef CONFIG_SPARC
 438         {
 439                 .ctl_name       = KERN_SPARC_REBOOT,
 440                 .procname       = "reboot-cmd",
 441                 .data           = reboot_command,
 442                 .maxlen         = 256,
 443                 .mode           = 0644,
 444                 .proc_handler   = &proc_dostring,
 445                 .strategy       = &sysctl_string,
 446         },
 447         {
 448                 .ctl_name       = KERN_SPARC_STOP_A,
 449                 .procname       = "stop-a",
 450                 .data           = &stop_a_enabled,
 451                 .maxlen         = sizeof (int),
 452                 .mode           = 0644,
 453                 .proc_handler   = &proc_dointvec,
 454         },
 455         {
 456                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 457                 .procname       = "scons-poweroff",
 458                 .data           = &scons_pwroff,
 459                 .maxlen         = sizeof (int),
 460                 .mode           = 0644,
 461                 .proc_handler   = &proc_dointvec,
 462         },
 463 #endif
 464 #ifdef CONFIG_SPARC64
 465         {
 466                 .ctl_name       = CTL_UNNUMBERED,
 467                 .procname       = "tsb-ratio",
 468                 .data           = &sysctl_tsb_ratio,
 469                 .maxlen         = sizeof (int),
 470                 .mode           = 0644,
 471                 .proc_handler   = &proc_dointvec,
 472         },
 473 #endif
 474 #ifdef __hppa__
 475         {
 476                 .ctl_name       = KERN_HPPA_PWRSW,
 477                 .procname       = "soft-power",
 478                 .data           = &pwrsw_enabled,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = &proc_dointvec,
 482         },
 483         {
 484                 .ctl_name       = KERN_HPPA_UNALIGNED,
 485                 .procname       = "unaligned-trap",
 486                 .data           = &unaligned_enabled,
 487                 .maxlen         = sizeof (int),
 488                 .mode           = 0644,
 489                 .proc_handler   = &proc_dointvec,
 490         },
 491 #endif
 492         {
 493                 .ctl_name       = KERN_CTLALTDEL,
 494                 .procname       = "ctrl-alt-del",
 495                 .data           = &C_A_D,
 496                 .maxlen         = sizeof(int),
 497                 .mode           = 0644,
 498                 .proc_handler   = &proc_dointvec,
 499         },
 500 #ifdef CONFIG_FUNCTION_TRACER
 501         {
 502                 .ctl_name       = CTL_UNNUMBERED,
 503                 .procname       = "ftrace_enabled",
 504                 .data           = &ftrace_enabled,
 505                 .maxlen         = sizeof(int),
 506                 .mode           = 0644,
 507                 .proc_handler   = &ftrace_enable_sysctl,
 508         },
 509 #endif
 510 #ifdef CONFIG_STACK_TRACER
 511         {
 512                 .ctl_name       = CTL_UNNUMBERED,
 513                 .procname       = "stack_tracer_enabled",
 514                 .data           = &stack_tracer_enabled,
 515                 .maxlen         = sizeof(int),
 516                 .mode           = 0644,
 517                 .proc_handler   = &stack_trace_sysctl,
 518         },
 519 #endif
 520 #ifdef CONFIG_TRACING
 521         {
 522                 .ctl_name       = CTL_UNNUMBERED,
 523                 .procname       = "ftrace_dump_on_oops",
 524                 .data           = &ftrace_dump_on_oops,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = &proc_dointvec,
 528         },
 529 #endif
 530 #ifdef CONFIG_MODULES
 531         {
 532                 .ctl_name       = KERN_MODPROBE,
 533                 .procname       = "modprobe",
 534                 .data           = &modprobe_path,
 535                 .maxlen         = KMOD_PATH_LEN,
 536                 .mode           = 0644,
 537                 .proc_handler   = &proc_dostring,
 538                 .strategy       = &sysctl_string,
 539         },
 540         {
 541                 .ctl_name       = CTL_UNNUMBERED,
 542                 .procname       = "modules_disabled",
 543                 .data           = &modules_disabled,
 544                 .maxlen         = sizeof(int),
 545                 .mode           = 0644,
 546                 /* only handle a transition from default "0" to "1" */
 547                 .proc_handler   = &proc_dointvec_minmax,
 548                 .extra1         = &one,
 549                 .extra2         = &one,
 550         },
 551 #endif
 552 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 553         {
 554                 .ctl_name       = KERN_HOTPLUG,
 555                 .procname       = "hotplug",
 556                 .data           = &uevent_helper,
 557                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 558                 .mode           = 0644,
 559                 .proc_handler   = &proc_dostring,
 560                 .strategy       = &sysctl_string,
 561         },
 562 #endif
 563 #ifdef CONFIG_CHR_DEV_SG
 564         {
 565                 .ctl_name       = KERN_SG_BIG_BUFF,
 566                 .procname       = "sg-big-buff",
 567                 .data           = &sg_big_buff,
 568                 .maxlen         = sizeof (int),
 569                 .mode           = 0444,
 570                 .proc_handler   = &proc_dointvec,
 571         },
 572 #endif
 573 #ifdef CONFIG_BSD_PROCESS_ACCT
 574         {
 575                 .ctl_name       = KERN_ACCT,
 576                 .procname       = "acct",
 577                 .data           = &acct_parm,
 578                 .maxlen         = 3*sizeof(int),
 579                 .mode           = 0644,
 580                 .proc_handler   = &proc_dointvec,
 581         },
 582 #endif
 583 #ifdef CONFIG_MAGIC_SYSRQ
 584         {
 585                 .ctl_name       = KERN_SYSRQ,
 586                 .procname       = "sysrq",
 587                 .data           = &__sysrq_enabled,
 588                 .maxlen         = sizeof (int),
 589                 .mode           = 0644,
 590                 .proc_handler   = &proc_dointvec,
 591         },
 592 #endif
 593 #ifdef CONFIG_PROC_SYSCTL
 594         {
 595                 .procname       = "cad_pid",
 596                 .data           = NULL,
 597                 .maxlen         = sizeof (int),
 598                 .mode           = 0600,
 599                 .proc_handler   = &proc_do_cad_pid,
 600         },
 601 #endif
 602         {
 603                 .ctl_name       = KERN_MAX_THREADS,
 604                 .procname       = "threads-max",
 605                 .data           = &max_threads,
 606                 .maxlen         = sizeof(int),
 607                 .mode           = 0644,
 608                 .proc_handler   = &proc_dointvec,
 609         },
 610         {
 611                 .ctl_name       = KERN_RANDOM,
 612                 .procname       = "random",
 613                 .mode           = 0555,
 614                 .child          = random_table,
 615         },
 616         {
 617                 .ctl_name       = KERN_OVERFLOWUID,
 618                 .procname       = "overflowuid",
 619                 .data           = &overflowuid,
 620                 .maxlen         = sizeof(int),
 621                 .mode           = 0644,
 622                 .proc_handler   = &proc_dointvec_minmax,
 623                 .strategy       = &sysctl_intvec,
 624                 .extra1         = &minolduid,
 625                 .extra2         = &maxolduid,
 626         },
 627         {
 628                 .ctl_name       = KERN_OVERFLOWGID,
 629                 .procname       = "overflowgid",
 630                 .data           = &overflowgid,
 631                 .maxlen         = sizeof(int),
 632                 .mode           = 0644,
 633                 .proc_handler   = &proc_dointvec_minmax,
 634                 .strategy       = &sysctl_intvec,
 635                 .extra1         = &minolduid,
 636                 .extra2         = &maxolduid,
 637         },
 638 #ifdef CONFIG_S390
 639 #ifdef CONFIG_MATHEMU
 640         {
 641                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 642                 .procname       = "ieee_emulation_warnings",
 643                 .data           = &sysctl_ieee_emulation_warnings,
 644                 .maxlen         = sizeof(int),
 645                 .mode           = 0644,
 646                 .proc_handler   = &proc_dointvec,
 647         },
 648 #endif
 649         {
 650                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 651                 .procname       = "userprocess_debug",
 652                 .data           = &sysctl_userprocess_debug,
 653                 .maxlen         = sizeof(int),
 654                 .mode           = 0644,
 655                 .proc_handler   = &proc_dointvec,
 656         },
 657 #endif
 658         {
 659                 .ctl_name       = KERN_PIDMAX,
 660                 .procname       = "pid_max",
 661                 .data           = &pid_max,
 662                 .maxlen         = sizeof (int),
 663                 .mode           = 0644,
 664                 .proc_handler   = &proc_dointvec_minmax,
 665                 .strategy       = sysctl_intvec,
 666                 .extra1         = &pid_max_min,
 667                 .extra2         = &pid_max_max,
 668         },
 669         {
 670                 .ctl_name       = KERN_PANIC_ON_OOPS,
 671                 .procname       = "panic_on_oops",
 672                 .data           = &panic_on_oops,
 673                 .maxlen         = sizeof(int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #if defined CONFIG_PRINTK
 678         {
 679                 .ctl_name       = KERN_PRINTK,
 680                 .procname       = "printk",
 681                 .data           = &console_loglevel,
 682                 .maxlen         = 4*sizeof(int),
 683                 .mode           = 0644,
 684                 .proc_handler   = &proc_dointvec,
 685         },
 686         {
 687                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 688                 .procname       = "printk_ratelimit",
 689                 .data           = &printk_ratelimit_state.interval,
 690                 .maxlen         = sizeof(int),
 691                 .mode           = 0644,
 692                 .proc_handler   = &proc_dointvec_jiffies,
 693                 .strategy       = &sysctl_jiffies,
 694         },
 695         {
 696                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 697                 .procname       = "printk_ratelimit_burst",
 698                 .data           = &printk_ratelimit_state.burst,
 699                 .maxlen         = sizeof(int),
 700                 .mode           = 0644,
 701                 .proc_handler   = &proc_dointvec,
 702         },
 703 #endif
 704         {
 705                 .ctl_name       = KERN_NGROUPS_MAX,
 706                 .procname       = "ngroups_max",
 707                 .data           = &ngroups_max,
 708                 .maxlen         = sizeof (int),
 709                 .mode           = 0444,
 710                 .proc_handler   = &proc_dointvec,
 711         },
 712 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 713         {
 714                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 715                 .procname       = "unknown_nmi_panic",
 716                 .data           = &unknown_nmi_panic,
 717                 .maxlen         = sizeof (int),
 718                 .mode           = 0644,
 719                 .proc_handler   = &proc_dointvec,
 720         },
 721         {
 722                 .procname       = "nmi_watchdog",
 723                 .data           = &nmi_watchdog_enabled,
 724                 .maxlen         = sizeof (int),
 725                 .mode           = 0644,
 726                 .proc_handler   = &proc_nmi_enabled,
 727         },
 728 #endif
 729 #if defined(CONFIG_X86)
 730         {
 731                 .ctl_name       = KERN_PANIC_ON_NMI,
 732                 .procname       = "panic_on_unrecovered_nmi",
 733                 .data           = &panic_on_unrecovered_nmi,
 734                 .maxlen         = sizeof(int),
 735                 .mode           = 0644,
 736                 .proc_handler   = &proc_dointvec,
 737         },
 738         {
 739                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 740                 .procname       = "bootloader_type",
 741                 .data           = &bootloader_type,
 742                 .maxlen         = sizeof (int),
 743                 .mode           = 0444,
 744                 .proc_handler   = &proc_dointvec,
 745         },
 746         {
 747                 .ctl_name       = CTL_UNNUMBERED,
 748                 .procname       = "bootloader_version",
 749                 .data           = &bootloader_version,
 750                 .maxlen         = sizeof (int),
 751                 .mode           = 0444,
 752                 .proc_handler   = &proc_dointvec,
 753         },
 754         {
 755                 .ctl_name       = CTL_UNNUMBERED,
 756                 .procname       = "kstack_depth_to_print",
 757                 .data           = &kstack_depth_to_print,
 758                 .maxlen         = sizeof(int),
 759                 .mode           = 0644,
 760                 .proc_handler   = &proc_dointvec,
 761         },
 762         {
 763                 .ctl_name       = CTL_UNNUMBERED,
 764                 .procname       = "io_delay_type",
 765                 .data           = &io_delay_type,
 766                 .maxlen         = sizeof(int),
 767                 .mode           = 0644,
 768                 .proc_handler   = &proc_dointvec,
 769         },
 770 #endif
 771 #if defined(CONFIG_MMU)
 772         {
 773                 .ctl_name       = KERN_RANDOMIZE,
 774                 .procname       = "randomize_va_space",
 775                 .data           = &randomize_va_space,
 776                 .maxlen         = sizeof(int),
 777                 .mode           = 0644,
 778                 .proc_handler   = &proc_dointvec,
 779         },
 780 #endif
 781 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 782         {
 783                 .ctl_name       = KERN_SPIN_RETRY,
 784                 .procname       = "spin_retry",
 785                 .data           = &spin_retry,
 786                 .maxlen         = sizeof (int),
 787                 .mode           = 0644,
 788                 .proc_handler   = &proc_dointvec,
 789         },
 790 #endif
 791 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 792         {
 793                 .procname       = "acpi_video_flags",
 794                 .data           = &acpi_realmode_flags,
 795                 .maxlen         = sizeof (unsigned long),
 796                 .mode           = 0644,
 797                 .proc_handler   = &proc_doulongvec_minmax,
 798         },
 799 #endif
 800 #ifdef CONFIG_IA64
 801         {
 802                 .ctl_name       = KERN_IA64_UNALIGNED,
 803                 .procname       = "ignore-unaligned-usertrap",
 804                 .data           = &no_unaligned_warning,
 805                 .maxlen         = sizeof (int),
 806                 .mode           = 0644,
 807                 .proc_handler   = &proc_dointvec,
 808         },
 809         {
 810                 .ctl_name       = CTL_UNNUMBERED,
 811                 .procname       = "unaligned-dump-stack",
 812                 .data           = &unaligned_dump_stack,
 813                 .maxlen         = sizeof (int),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dointvec,
 816         },
 817 #endif
 818 #ifdef CONFIG_DETECT_SOFTLOCKUP
 819         {
 820                 .ctl_name       = CTL_UNNUMBERED,
 821                 .procname       = "softlockup_panic",
 822                 .data           = &softlockup_panic,
 823                 .maxlen         = sizeof(int),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_dointvec_minmax,
 826                 .strategy       = &sysctl_intvec,
 827                 .extra1         = &zero,
 828                 .extra2         = &one,
 829         },
 830         {
 831                 .ctl_name       = CTL_UNNUMBERED,
 832                 .procname       = "softlockup_thresh",
 833                 .data           = &softlockup_thresh,
 834                 .maxlen         = sizeof(int),
 835                 .mode           = 0644,
 836                 .proc_handler   = &proc_dosoftlockup_thresh,
 837                 .strategy       = &sysctl_intvec,
 838                 .extra1         = &neg_one,
 839                 .extra2         = &sixty,
 840         },
 841 #endif
 842 #ifdef CONFIG_DETECT_HUNG_TASK
 843         {
 844                 .ctl_name       = CTL_UNNUMBERED,
 845                 .procname       = "hung_task_panic",
 846                 .data           = &sysctl_hung_task_panic,
 847                 .maxlen         = sizeof(int),
 848                 .mode           = 0644,
 849                 .proc_handler   = &proc_dointvec_minmax,
 850                 .strategy       = &sysctl_intvec,
 851                 .extra1         = &zero,
 852                 .extra2         = &one,
 853         },
 854         {
 855                 .ctl_name       = CTL_UNNUMBERED,
 856                 .procname       = "hung_task_check_count",
 857                 .data           = &sysctl_hung_task_check_count,
 858                 .maxlen         = sizeof(unsigned long),
 859                 .mode           = 0644,
 860                 .proc_handler   = &proc_doulongvec_minmax,
 861                 .strategy       = &sysctl_intvec,
 862         },
 863         {
 864                 .ctl_name       = CTL_UNNUMBERED,
 865                 .procname       = "hung_task_timeout_secs",
 866                 .data           = &sysctl_hung_task_timeout_secs,
 867                 .maxlen         = sizeof(unsigned long),
 868                 .mode           = 0644,
 869                 .proc_handler   = &proc_dohung_task_timeout_secs,
 870                 .strategy       = &sysctl_intvec,
 871         },
 872         {
 873                 .ctl_name       = CTL_UNNUMBERED,
 874                 .procname       = "hung_task_warnings",
 875                 .data           = &sysctl_hung_task_warnings,
 876                 .maxlen         = sizeof(unsigned long),
 877                 .mode           = 0644,
 878                 .proc_handler   = &proc_doulongvec_minmax,
 879                 .strategy       = &sysctl_intvec,
 880         },
 881 #endif
 882 #ifdef CONFIG_COMPAT
 883         {
 884                 .ctl_name       = KERN_COMPAT_LOG,
 885                 .procname       = "compat-log",
 886                 .data           = &compat_log,
 887                 .maxlen         = sizeof (int),
 888                 .mode           = 0644,
 889                 .proc_handler   = &proc_dointvec,
 890         },
 891 #endif
 892 #ifdef CONFIG_RT_MUTEXES
 893         {
 894                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 895                 .procname       = "max_lock_depth",
 896                 .data           = &max_lock_depth,
 897                 .maxlen         = sizeof(int),
 898                 .mode           = 0644,
 899                 .proc_handler   = &proc_dointvec,
 900         },
 901 #endif
 902         {
 903                 .ctl_name       = CTL_UNNUMBERED,
 904                 .procname       = "poweroff_cmd",
 905                 .data           = &poweroff_cmd,
 906                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 907                 .mode           = 0644,
 908                 .proc_handler   = &proc_dostring,
 909                 .strategy       = &sysctl_string,
 910         },
 911 #ifdef CONFIG_KEYS
 912         {
 913                 .ctl_name       = CTL_UNNUMBERED,
 914                 .procname       = "keys",
 915                 .mode           = 0555,
 916                 .child          = key_sysctls,
 917         },
 918 #endif
 919 #ifdef CONFIG_RCU_TORTURE_TEST
 920         {
 921                 .ctl_name       = CTL_UNNUMBERED,
 922                 .procname       = "rcutorture_runnable",
 923                 .data           = &rcutorture_runnable,
 924                 .maxlen         = sizeof(int),
 925                 .mode           = 0644,
 926                 .proc_handler   = &proc_dointvec,
 927         },
 928 #endif
 929 #ifdef CONFIG_SLOW_WORK
 930         {
 931                 .ctl_name       = CTL_UNNUMBERED,
 932                 .procname       = "slow-work",
 933                 .mode           = 0555,
 934                 .child          = slow_work_sysctls,
 935         },
 936 #endif
 937 #ifdef CONFIG_PERF_COUNTERS
 938         {
 939                 .ctl_name       = CTL_UNNUMBERED,
 940                 .procname       = "perf_counter_paranoid",
 941                 .data           = &sysctl_perf_counter_paranoid,
 942                 .maxlen         = sizeof(sysctl_perf_counter_paranoid),
 943                 .mode           = 0644,
 944                 .proc_handler   = &proc_dointvec,
 945         },
 946         {
 947                 .ctl_name       = CTL_UNNUMBERED,
 948                 .procname       = "perf_counter_mlock_kb",
 949                 .data           = &sysctl_perf_counter_mlock,
 950                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
 951                 .mode           = 0644,
 952                 .proc_handler   = &proc_dointvec,
 953         },
 954         {
 955                 .ctl_name       = CTL_UNNUMBERED,
 956                 .procname       = "perf_counter_max_sample_rate",
 957                 .data           = &sysctl_perf_counter_sample_rate,
 958                 .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
 959                 .mode           = 0644,
 960                 .proc_handler   = &proc_dointvec,
 961         },
 962 #endif
 963 #ifdef CONFIG_KMEMCHECK
 964         {
 965                 .ctl_name       = CTL_UNNUMBERED,
 966                 .procname       = "kmemcheck",
 967                 .data           = &kmemcheck_enabled,
 968                 .maxlen         = sizeof(int),
 969                 .mode           = 0644,
 970                 .proc_handler   = &proc_dointvec,
 971         },
 972 #endif
 973
 974 /*
 975  * NOTE: do not add new entries to this table unless you have read
 976  * Documentation/sysctl/ctl_unnumbered.txt
 977  */
 978         { .ctl_name = 0 }
 979 };
 980
 981 static struct ctl_table vm_table[] = {
 982         {
 983                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 984                 .procname       = "overcommit_memory",
 985                 .data           = &sysctl_overcommit_memory,
 986                 .maxlen         = sizeof(sysctl_overcommit_memory),
 987                 .mode           = 0644,
 988                 .proc_handler   = &proc_dointvec,
 989         },
 990         {
 991                 .ctl_name       = VM_PANIC_ON_OOM,
 992                 .procname       = "panic_on_oom",
 993                 .data           = &sysctl_panic_on_oom,
 994                 .maxlen         = sizeof(sysctl_panic_on_oom),
 995                 .mode           = 0644,
 996                 .proc_handler   = &proc_dointvec,
 997         },
 998         {
 999                 .ctl_name       = CTL_UNNUMBERED,
1000                 .procname       = "oom_kill_allocating_task",
1001                 .data           = &sysctl_oom_kill_allocating_task,
1002                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1003                 .mode           = 0644,
1004                 .proc_handler   = &proc_dointvec,
1005         },
1006         {
1007                 .ctl_name       = CTL_UNNUMBERED,
1008                 .procname       = "oom_dump_tasks",
1009                 .data           = &sysctl_oom_dump_tasks,
1010                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1011                 .mode           = 0644,
1012                 .proc_handler   = &proc_dointvec,
1013         },
1014         {
1015                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1016                 .procname       = "overcommit_ratio",
1017                 .data           = &sysctl_overcommit_ratio,
1018                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1019                 .mode           = 0644,
1020                 .proc_handler   = &proc_dointvec,
1021         },
1022         {
1023                 .ctl_name       = VM_PAGE_CLUSTER,
1024                 .procname       = "page-cluster",
1025                 .data           = &page_cluster,
1026                 .maxlen         = sizeof(int),
1027                 .mode           = 0644,
1028                 .proc_handler   = &proc_dointvec,
1029         },
1030         {
1031                 .ctl_name       = VM_DIRTY_BACKGROUND,
1032                 .procname       = "dirty_background_ratio",
1033                 .data           = &dirty_background_ratio,
1034                 .maxlen         = sizeof(dirty_background_ratio),
1035                 .mode           = 0644,
1036                 .proc_handler   = &dirty_background_ratio_handler,
1037                 .strategy       = &sysctl_intvec,
1038                 .extra1         = &zero,
1039                 .extra2         = &one_hundred,
1040         },
1041         {
1042                 .ctl_name       = CTL_UNNUMBERED,
1043                 .procname       = "dirty_background_bytes",
1044                 .data           = &dirty_background_bytes,
1045                 .maxlen         = sizeof(dirty_background_bytes),
1046                 .mode           = 0644,
1047                 .proc_handler   = &dirty_background_bytes_handler,
1048                 .strategy       = &sysctl_intvec,
1049                 .extra1         = &one_ul,
1050         },
1051         {
1052                 .ctl_name       = VM_DIRTY_RATIO,
1053                 .procname       = "dirty_ratio",
1054                 .data           = &vm_dirty_ratio,
1055                 .maxlen         = sizeof(vm_dirty_ratio),
1056                 .mode           = 0644,
1057                 .proc_handler   = &dirty_ratio_handler,
1058                 .strategy       = &sysctl_intvec,
1059                 .extra1         = &zero,
1060                 .extra2         = &one_hundred,
1061         },
1062         {
1063                 .ctl_name       = CTL_UNNUMBERED,
1064                 .procname       = "dirty_bytes",
1065                 .data           = &vm_dirty_bytes,
1066                 .maxlen         = sizeof(vm_dirty_bytes),
1067                 .mode           = 0644,
1068                 .proc_handler   = &dirty_bytes_handler,
1069                 .strategy       = &sysctl_intvec,
1070                 .extra1         = &dirty_bytes_min,
1071         },
1072         {
1073                 .procname       = "dirty_writeback_centisecs",
1074                 .data           = &dirty_writeback_interval,
1075                 .maxlen         = sizeof(dirty_writeback_interval),
1076                 .mode           = 0644,
1077                 .proc_handler   = &dirty_writeback_centisecs_handler,
1078         },
1079         {
1080                 .procname       = "dirty_expire_centisecs",
1081                 .data           = &dirty_expire_interval,
1082                 .maxlen         = sizeof(dirty_expire_interval),
1083                 .mode           = 0644,
1084                 .proc_handler   = &proc_dointvec,
1085         },
1086         {
1087                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1088                 .procname       = "nr_pdflush_threads",
1089                 .data           = &nr_pdflush_threads,
1090                 .maxlen         = sizeof nr_pdflush_threads,
1091                 .mode           = 0444 /* read-only*/,
1092                 .proc_handler   = &proc_dointvec,
1093         },
1094         {
1095                 .ctl_name       = VM_SWAPPINESS,
1096                 .procname       = "swappiness",
1097                 .data           = &vm_swappiness,
1098                 .maxlen         = sizeof(vm_swappiness),
1099                 .mode           = 0644,
1100                 .proc_handler   = &proc_dointvec_minmax,
1101                 .strategy       = &sysctl_intvec,
1102                 .extra1         = &zero,
1103                 .extra2         = &one_hundred,
1104         },
1105 #ifdef CONFIG_HUGETLB_PAGE
1106          {
1107                 .procname       = "nr_hugepages",
1108                 .data           = NULL,
1109                 .maxlen         = sizeof(unsigned long),
1110                 .mode           = 0644,
1111                 .proc_handler   = &hugetlb_sysctl_handler,
1112                 .extra1         = (void *)&hugetlb_zero,
1113                 .extra2         = (void *)&hugetlb_infinity,
1114          },
1115          {
1116                 .ctl_name       = VM_HUGETLB_GROUP,
1117                 .procname       = "hugetlb_shm_group",
1118                 .data           = &sysctl_hugetlb_shm_group,
1119                 .maxlen         = sizeof(gid_t),
1120                 .mode           = 0644,
1121                 .proc_handler   = &proc_dointvec,
1122          },
1123          {
1124                 .ctl_name       = CTL_UNNUMBERED,
1125                 .procname       = "hugepages_treat_as_movable",
1126                 .data           = &hugepages_treat_as_movable,
1127                 .maxlen         = sizeof(int),
1128                 .mode           = 0644,
1129                 .proc_handler   = &hugetlb_treat_movable_handler,
1130         },
1131         {
1132                 .ctl_name       = CTL_UNNUMBERED,
1133                 .procname       = "nr_overcommit_hugepages",
1134                 .data           = NULL,
1135                 .maxlen         = sizeof(unsigned long),
1136                 .mode           = 0644,
1137                 .proc_handler   = &hugetlb_overcommit_handler,
1138                 .extra1         = (void *)&hugetlb_zero,
1139                 .extra2         = (void *)&hugetlb_infinity,
1140         },
1141 #endif
1142         {
1143                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1144                 .procname       = "lowmem_reserve_ratio",
1145                 .data           = &sysctl_lowmem_reserve_ratio,
1146                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1147                 .mode           = 0644,
1148                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1149                 .strategy       = &sysctl_intvec,
1150         },
1151         {
1152                 .ctl_name       = VM_DROP_PAGECACHE,
1153                 .procname       = "drop_caches",
1154                 .data           = &sysctl_drop_caches,
1155                 .maxlen         = sizeof(int),
1156                 .mode           = 0644,
1157                 .proc_handler   = drop_caches_sysctl_handler,
1158                 .strategy       = &sysctl_intvec,
1159         },
1160         {
1161                 .ctl_name       = VM_MIN_FREE_KBYTES,
1162                 .procname       = "min_free_kbytes",
1163                 .data           = &min_free_kbytes,
1164                 .maxlen         = sizeof(min_free_kbytes),
1165                 .mode           = 0644,
1166                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1167                 .strategy       = &sysctl_intvec,
1168                 .extra1         = &zero,
1169         },
1170         {
1171                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1172                 .procname       = "percpu_pagelist_fraction",
1173                 .data           = &percpu_pagelist_fraction,
1174                 .maxlen         = sizeof(percpu_pagelist_fraction),
1175                 .mode           = 0644,
1176                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1177                 .strategy       = &sysctl_intvec,
1178                 .extra1         = &min_percpu_pagelist_fract,
1179         },
1180 #ifdef CONFIG_MMU
1181         {
1182                 .ctl_name       = VM_MAX_MAP_COUNT,
1183                 .procname       = "max_map_count",
1184                 .data           = &sysctl_max_map_count,
1185                 .maxlen         = sizeof(sysctl_max_map_count),
1186                 .mode           = 0644,
1187                 .proc_handler   = &proc_dointvec
1188         },
1189 #else
1190         {
1191                 .ctl_name       = CTL_UNNUMBERED,
1192                 .procname       = "nr_trim_pages",
1193                 .data           = &sysctl_nr_trim_pages,
1194                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1195                 .mode           = 0644,
1196                 .proc_handler   = &proc_dointvec_minmax,
1197                 .strategy       = &sysctl_intvec,
1198                 .extra1         = &zero,
1199         },
1200 #endif
1201         {
1202                 .ctl_name       = VM_LAPTOP_MODE,
1203                 .procname       = "laptop_mode",
1204                 .data           = &laptop_mode,
1205                 .maxlen         = sizeof(laptop_mode),
1206                 .mode           = 0644,
1207                 .proc_handler   = &proc_dointvec_jiffies,
1208                 .strategy       = &sysctl_jiffies,
1209         },
1210         {
1211                 .ctl_name       = VM_BLOCK_DUMP,
1212                 .procname       = "block_dump",
1213                 .data           = &block_dump,
1214                 .maxlen         = sizeof(block_dump),
1215                 .mode           = 0644,
1216                 .proc_handler   = &proc_dointvec,
1217                 .strategy       = &sysctl_intvec,
1218                 .extra1         = &zero,
1219         },
1220         {
1221                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1222                 .procname       = "vfs_cache_pressure",
1223                 .data           = &sysctl_vfs_cache_pressure,
1224                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1225                 .mode           = 0644,
1226                 .proc_handler   = &proc_dointvec,
1227                 .strategy       = &sysctl_intvec,
1228                 .extra1         = &zero,
1229         },
1230 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1231         {
1232                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1233                 .procname       = "legacy_va_layout",
1234                 .data           = &sysctl_legacy_va_layout,
1235                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1236                 .mode           = 0644,
1237                 .proc_handler   = &proc_dointvec,
1238                 .strategy       = &sysctl_intvec,
1239                 .extra1         = &zero,
1240         },
1241 #endif
1242 #ifdef CONFIG_NUMA
1243         {
1244                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1245                 .procname       = "zone_reclaim_mode",
1246                 .data           = &zone_reclaim_mode,
1247                 .maxlen         = sizeof(zone_reclaim_mode),
1248                 .mode           = 0644,
1249                 .proc_handler   = &proc_dointvec,
1250                 .strategy       = &sysctl_intvec,
1251                 .extra1         = &zero,
1252         },
1253         {
1254                 .ctl_name       = VM_MIN_UNMAPPED,
1255                 .procname       = "min_unmapped_ratio",
1256                 .data           = &sysctl_min_unmapped_ratio,
1257                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1258                 .mode           = 0644,
1259                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1260                 .strategy       = &sysctl_intvec,
1261                 .extra1         = &zero,
1262                 .extra2         = &one_hundred,
1263         },
1264         {
1265                 .ctl_name       = VM_MIN_SLAB,
1266                 .procname       = "min_slab_ratio",
1267                 .data           = &sysctl_min_slab_ratio,
1268                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1269                 .mode           = 0644,
1270                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1271                 .strategy       = &sysctl_intvec,
1272                 .extra1         = &zero,
1273                 .extra2         = &one_hundred,
1274         },
1275 #endif
1276 #ifdef CONFIG_SMP
1277         {
1278                 .ctl_name       = CTL_UNNUMBERED,
1279                 .procname       = "stat_interval",
1280                 .data           = &sysctl_stat_interval,
1281                 .maxlen         = sizeof(sysctl_stat_interval),
1282                 .mode           = 0644,
1283                 .proc_handler   = &proc_dointvec_jiffies,
1284                 .strategy       = &sysctl_jiffies,
1285         },
1286 #endif
1287         {
1288                 .ctl_name       = CTL_UNNUMBERED,
1289                 .procname       = "mmap_min_addr",
1290                 .data           = &mmap_min_addr,
1291                 .maxlen         = sizeof(unsigned long),
1292                 .mode           = 0644,
1293                 .proc_handler   = &proc_doulongvec_minmax,
1294         },
1295 #ifdef CONFIG_NUMA
1296         {
1297                 .ctl_name       = CTL_UNNUMBERED,
1298                 .procname       = "numa_zonelist_order",
1299                 .data           = &numa_zonelist_order,
1300                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1301                 .mode           = 0644,
1302                 .proc_handler   = &numa_zonelist_order_handler,
1303                 .strategy       = &sysctl_string,
1304         },
1305 #endif
1306 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1307    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1308         {
1309                 .ctl_name       = VM_VDSO_ENABLED,
1310                 .procname       = "vdso_enabled",
1311                 .data           = &vdso_enabled,
1312                 .maxlen         = sizeof(vdso_enabled),
1313                 .mode           = 0644,
1314                 .proc_handler   = &proc_dointvec,
1315                 .strategy       = &sysctl_intvec,
1316                 .extra1         = &zero,
1317         },
1318 #endif
1319 #ifdef CONFIG_HIGHMEM
1320         {
1321                 .ctl_name       = CTL_UNNUMBERED,
1322                 .procname       = "highmem_is_dirtyable",
1323                 .data           = &vm_highmem_is_dirtyable,
1324                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1325                 .mode           = 0644,
1326                 .proc_handler   = &proc_dointvec_minmax,
1327                 .strategy       = &sysctl_intvec,
1328                 .extra1         = &zero,
1329                 .extra2         = &one,
1330         },
1331 #endif
1332 #ifdef CONFIG_UNEVICTABLE_LRU
1333         {
1334                 .ctl_name       = CTL_UNNUMBERED,
1335                 .procname       = "scan_unevictable_pages",
1336                 .data           = &scan_unevictable_pages,
1337                 .maxlen         = sizeof(scan_unevictable_pages),
1338                 .mode           = 0644,
1339                 .proc_handler   = &scan_unevictable_handler,
1340         },
1341 #endif
1342 /*
1343  * NOTE: do not add new entries to this table unless you have read
1344  * Documentation/sysctl/ctl_unnumbered.txt
1345  */
1346         { .ctl_name = 0 }
1347 };
1348
1349 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1350 static struct ctl_table binfmt_misc_table[] = {
1351         { .ctl_name = 0 }
1352 };
1353 #endif
1354
1355 static struct ctl_table fs_table[] = {
1356         {
1357                 .ctl_name       = FS_NRINODE,
1358                 .procname       = "inode-nr",
1359                 .data           = &inodes_stat,
1360                 .maxlen         = 2*sizeof(int),
1361                 .mode           = 0444,
1362                 .proc_handler   = &proc_dointvec,
1363         },
1364         {
1365                 .ctl_name       = FS_STATINODE,
1366                 .procname       = "inode-state",
1367                 .data           = &inodes_stat,
1368                 .maxlen         = 7*sizeof(int),
1369                 .mode           = 0444,
1370                 .proc_handler   = &proc_dointvec,
1371         },
1372         {
1373                 .procname       = "file-nr",
1374                 .data           = &files_stat,
1375                 .maxlen         = 3*sizeof(int),
1376                 .mode           = 0444,
1377                 .proc_handler   = &proc_nr_files,
1378         },
1379         {
1380                 .ctl_name       = FS_MAXFILE,
1381                 .procname       = "file-max",
1382                 .data           = &files_stat.max_files,
1383                 .maxlen         = sizeof(int),
1384                 .mode           = 0644,
1385                 .proc_handler   = &proc_dointvec,
1386         },
1387         {
1388                 .ctl_name       = CTL_UNNUMBERED,
1389                 .procname       = "nr_open",
1390                 .data           = &sysctl_nr_open,
1391                 .maxlen         = sizeof(int),
1392                 .mode           = 0644,
1393                 .proc_handler   = &proc_dointvec_minmax,
1394                 .extra1         = &sysctl_nr_open_min,
1395                 .extra2         = &sysctl_nr_open_max,
1396         },
1397         {
1398                 .ctl_name       = FS_DENTRY,
1399                 .procname       = "dentry-state",
1400                 .data           = &dentry_stat,
1401                 .maxlen         = 6*sizeof(int),
1402                 .mode           = 0444,
1403                 .proc_handler   = &proc_dointvec,
1404         },
1405         {
1406                 .ctl_name       = FS_OVERFLOWUID,
1407                 .procname       = "overflowuid",
1408                 .data           = &fs_overflowuid,
1409                 .maxlen         = sizeof(int),
1410                 .mode           = 0644,
1411                 .proc_handler   = &proc_dointvec_minmax,
1412                 .strategy       = &sysctl_intvec,
1413                 .extra1         = &minolduid,
1414                 .extra2         = &maxolduid,
1415         },
1416         {
1417                 .ctl_name       = FS_OVERFLOWGID,
1418                 .procname       = "overflowgid",
1419                 .data           = &fs_overflowgid,
1420                 .maxlen         = sizeof(int),
1421                 .mode           = 0644,
1422                 .proc_handler   = &proc_dointvec_minmax,
1423                 .strategy       = &sysctl_intvec,
1424                 .extra1         = &minolduid,
1425                 .extra2         = &maxolduid,
1426         },
1427 #ifdef CONFIG_FILE_LOCKING
1428         {
1429                 .ctl_name       = FS_LEASES,
1430                 .procname       = "leases-enable",
1431                 .data           = &leases_enable,
1432                 .maxlen         = sizeof(int),
1433                 .mode           = 0644,
1434                 .proc_handler   = &proc_dointvec,
1435         },
1436 #endif
1437 #ifdef CONFIG_DNOTIFY
1438         {
1439                 .ctl_name       = FS_DIR_NOTIFY,
1440                 .procname       = "dir-notify-enable",
1441                 .data           = &dir_notify_enable,
1442                 .maxlen         = sizeof(int),
1443                 .mode           = 0644,
1444                 .proc_handler   = &proc_dointvec,
1445         },
1446 #endif
1447 #ifdef CONFIG_MMU
1448 #ifdef CONFIG_FILE_LOCKING
1449         {
1450                 .ctl_name       = FS_LEASE_TIME,
1451                 .procname       = "lease-break-time",
1452                 .data           = &lease_break_time,
1453                 .maxlen         = sizeof(int),
1454                 .mode           = 0644,
1455                 .proc_handler   = &proc_dointvec,
1456         },
1457 #endif
1458 #ifdef CONFIG_AIO
1459         {
1460                 .procname       = "aio-nr",
1461                 .data           = &aio_nr,
1462                 .maxlen         = sizeof(aio_nr),
1463                 .mode           = 0444,
1464                 .proc_handler   = &proc_doulongvec_minmax,
1465         },
1466         {
1467                 .procname       = "aio-max-nr",
1468                 .data           = &aio_max_nr,
1469                 .maxlen         = sizeof(aio_max_nr),
1470                 .mode           = 0644,
1471                 .proc_handler   = &proc_doulongvec_minmax,
1472         },
1473 #endif /* CONFIG_AIO */
1474 #ifdef CONFIG_INOTIFY_USER
1475         {
1476                 .ctl_name       = FS_INOTIFY,
1477                 .procname       = "inotify",
1478                 .mode           = 0555,
1479                 .child          = inotify_table,
1480         },
1481 #endif
1482 #ifdef CONFIG_EPOLL
1483         {
1484                 .procname       = "epoll",
1485                 .mode           = 0555,
1486                 .child          = epoll_table,
1487         },
1488 #endif
1489 #endif
1490         {
1491                 .ctl_name       = KERN_SETUID_DUMPABLE,
1492                 .procname       = "suid_dumpable",
1493                 .data           = &suid_dumpable,
1494                 .maxlen         = sizeof(int),
1495                 .mode           = 0644,
1496                 .proc_handler   = &proc_dointvec_minmax,
1497                 .strategy       = &sysctl_intvec,
1498                 .extra1         = &zero,
1499                 .extra2         = &two,
1500         },
1501 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1502         {
1503                 .ctl_name       = CTL_UNNUMBERED,
1504                 .procname       = "binfmt_misc",
1505                 .mode           = 0555,
1506                 .child          = binfmt_misc_table,
1507         },
1508 #endif
1509 /*
1510  * NOTE: do not add new entries to this table unless you have read
1511  * Documentation/sysctl/ctl_unnumbered.txt
1512  */
1513         { .ctl_name = 0 }
1514 };
1515
1516 static struct ctl_table debug_table[] = {
1517 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1518         {
1519                 .ctl_name       = CTL_UNNUMBERED,
1520                 .procname       = "exception-trace",
1521                 .data           = &show_unhandled_signals,
1522                 .maxlen         = sizeof(int),
1523                 .mode           = 0644,
1524                 .proc_handler   = proc_dointvec
1525         },
1526 #endif
1527         { .ctl_name = 0 }
1528 };
1529
1530 static struct ctl_table dev_table[] = {
1531         { .ctl_name = 0 }
1532 };
1533
1534 static DEFINE_SPINLOCK(sysctl_lock);
1535
1536 /* called under sysctl_lock */
1537 static int use_table(struct ctl_table_header *p)
1538 {
1539         if (unlikely(p->unregistering))
1540                 return 0;
1541         p->used++;
1542         return 1;
1543 }
1544
1545 /* called under sysctl_lock */
1546 static void unuse_table(struct ctl_table_header *p)
1547 {
1548         if (!--p->used)
1549                 if (unlikely(p->unregistering))
1550                         complete(p->unregistering);
1551 }
1552
1553 /* called under sysctl_lock, will reacquire if has to wait */
1554 static void start_unregistering(struct ctl_table_header *p)
1555 {
1556         /*
1557          * if p->used is 0, nobody will ever touch that entry again;
1558          * we'll eliminate all paths to it before dropping sysctl_lock
1559          */
1560         if (unlikely(p->used)) {
1561                 struct completion wait;
1562                 init_completion(&wait);
1563                 p->unregistering = &wait;
1564                 spin_unlock(&sysctl_lock);
1565                 wait_for_completion(&wait);
1566                 spin_lock(&sysctl_lock);
1567         } else {
1568                 /* anything non-NULL; we'll never dereference it */
1569                 p->unregistering = ERR_PTR(-EINVAL);
1570         }
1571         /*
1572          * do not remove from the list until nobody holds it; walking the
1573          * list in do_sysctl() relies on that.
1574          */
1575         list_del_init(&p->ctl_entry);
1576 }
1577
1578 void sysctl_head_get(struct ctl_table_header *head)
1579 {
1580         spin_lock(&sysctl_lock);
1581         head->count++;
1582         spin_unlock(&sysctl_lock);
1583 }
1584
1585 void sysctl_head_put(struct ctl_table_header *head)
1586 {
1587         spin_lock(&sysctl_lock);
1588         if (!--head->count)
1589                 kfree(head);
1590         spin_unlock(&sysctl_lock);
1591 }
1592
1593 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1594 {
1595         if (!head)
1596                 BUG();
1597         spin_lock(&sysctl_lock);
1598         if (!use_table(head))
1599                 head = ERR_PTR(-ENOENT);
1600         spin_unlock(&sysctl_lock);
1601         return head;
1602 }
1603
1604 void sysctl_head_finish(struct ctl_table_header *head)
1605 {
1606         if (!head)
1607                 return;
1608         spin_lock(&sysctl_lock);
1609         unuse_table(head);
1610         spin_unlock(&sysctl_lock);
1611 }
1612
1613 static struct ctl_table_set *
1614 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1615 {
1616         struct ctl_table_set *set = &root->default_set;
1617         if (root->lookup)
1618                 set = root->lookup(root, namespaces);
1619         return set;
1620 }
1621
1622 static struct list_head *
1623 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1624 {
1625         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1626         return &set->list;
1627 }
1628
1629 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1630                                             struct ctl_table_header *prev)
1631 {
1632         struct ctl_table_root *root;
1633         struct list_head *header_list;
1634         struct ctl_table_header *head;
1635         struct list_head *tmp;
1636
1637         spin_lock(&sysctl_lock);
1638         if (prev) {
1639                 head = prev;
1640                 tmp = &prev->ctl_entry;
1641                 unuse_table(prev);
1642                 goto next;
1643         }
1644         tmp = &root_table_header.ctl_entry;
1645         for (;;) {
1646                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1647
1648                 if (!use_table(head))
1649                         goto next;
1650                 spin_unlock(&sysctl_lock);
1651                 return head;
1652         next:
1653                 root = head->root;
1654                 tmp = tmp->next;
1655                 header_list = lookup_header_list(root, namespaces);
1656                 if (tmp != header_list)
1657                         continue;
1658
1659                 do {
1660                         root = list_entry(root->root_list.next,
1661                                         struct ctl_table_root, root_list);
1662                         if (root == &sysctl_table_root)
1663                                 goto out;
1664                         header_list = lookup_header_list(root, namespaces);
1665                 } while (list_empty(header_list));
1666                 tmp = header_list->next;
1667         }
1668 out:
1669         spin_unlock(&sysctl_lock);
1670         return NULL;
1671 }
1672
1673 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1674 {
1675         return __sysctl_head_next(current->nsproxy, prev);
1676 }
1677
1678 void register_sysctl_root(struct ctl_table_root *root)
1679 {
1680         spin_lock(&sysctl_lock);
1681         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1682         spin_unlock(&sysctl_lock);
1683 }
1684
1685 #ifdef CONFIG_SYSCTL_SYSCALL
1686 /* Perform the actual read/write of a sysctl table entry. */
1687 static int do_sysctl_strategy(struct ctl_table_root *root,
1688                         struct ctl_table *table,
1689                         void __user *oldval, size_t __user *oldlenp,
1690                         void __user *newval, size_t newlen)
1691 {
1692         int op = 0, rc;
1693
1694         if (oldval)
1695                 op |= MAY_READ;
1696         if (newval)
1697                 op |= MAY_WRITE;
1698         if (sysctl_perm(root, table, op))
1699                 return -EPERM;
1700
1701         if (table->strategy) {
1702                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1703                 if (rc < 0)
1704                         return rc;
1705                 if (rc > 0)
1706                         return 0;
1707         }
1708
1709         /* If there is no strategy routine, or if the strategy returns
1710          * zero, proceed with automatic r/w */
1711         if (table->data && table->maxlen) {
1712                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1713                 if (rc < 0)
1714                         return rc;
1715         }
1716         return 0;
1717 }
1718
1719 static int parse_table(int __user *name, int nlen,
1720                        void __user *oldval, size_t __user *oldlenp,
1721                        void __user *newval, size_t newlen,
1722                        struct ctl_table_root *root,
1723                        struct ctl_table *table)
1724 {
1725         int n;
1726 repeat:
1727         if (!nlen)
1728                 return -ENOTDIR;
1729         if (get_user(n, name))
1730                 return -EFAULT;
1731         for ( ; table->ctl_name || table->procname; table++) {
1732                 if (!table->ctl_name)
1733                         continue;
1734                 if (n == table->ctl_name) {
1735                         int error;
1736                         if (table->child) {
1737                                 if (sysctl_perm(root, table, MAY_EXEC))
1738                                         return -EPERM;
1739                                 name++;
1740                                 nlen--;
1741                                 table = table->child;
1742                                 goto repeat;
1743                         }
1744                         error = do_sysctl_strategy(root, table,
1745                                                    oldval, oldlenp,
1746                                                    newval, newlen);
1747                         return error;
1748                 }
1749         }
1750         return -ENOTDIR;
1751 }
1752
1753 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1754                void __user *newval, size_t newlen)
1755 {
1756         struct ctl_table_header *head;
1757         int error = -ENOTDIR;
1758
1759         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1760                 return -ENOTDIR;
1761         if (oldval) {
1762                 int old_len;
1763                 if (!oldlenp || get_user(old_len, oldlenp))
1764                         return -EFAULT;
1765         }
1766
1767         for (head = sysctl_head_next(NULL); head;
1768                         head = sysctl_head_next(head)) {
1769                 error = parse_table(name, nlen, oldval, oldlenp,
1770                                         newval, newlen,
1771                                         head->root, head->ctl_table);
1772                 if (error != -ENOTDIR) {
1773                         sysctl_head_finish(head);
1774                         break;
1775                 }
1776         }
1777         return error;
1778 }
1779
1780 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1781 {
1782         struct __sysctl_args tmp;
1783         int error;
1784
1785         if (copy_from_user(&tmp, args, sizeof(tmp)))
1786                 return -EFAULT;
1787
1788         error = deprecated_sysctl_warning(&tmp);
1789         if (error)
1790                 goto out;
1791
1792         lock_kernel();
1793         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1794                           tmp.newval, tmp.newlen);
1795         unlock_kernel();
1796 out:
1797         return error;
1798 }
1799 #endif /* CONFIG_SYSCTL_SYSCALL */
1800
1801 /*
1802  * sysctl_perm does NOT grant the superuser all rights automatically, because
1803  * some sysctl variables are readonly even to root.
1804  */
1805
1806 static int test_perm(int mode, int op)
1807 {
1808         if (!current_euid())
1809                 mode >>= 6;
1810         else if (in_egroup_p(0))
1811                 mode >>= 3;
1812         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1813                 return 0;
1814         return -EACCES;
1815 }
1816
1817 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1818 {
1819         int error;
1820         int mode;
1821
1822         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1823         if (error)
1824                 return error;
1825
1826         if (root->permissions)
1827                 mode = root->permissions(root, current->nsproxy, table);
1828         else
1829                 mode = table->mode;
1830
1831         return test_perm(mode, op);
1832 }
1833
1834 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1835 {
1836         for (; table->ctl_name || table->procname; table++) {
1837                 table->parent = parent;
1838                 if (table->child)
1839                         sysctl_set_parent(table, table->child);
1840         }
1841 }
1842
1843 static __init int sysctl_init(void)
1844 {
1845         sysctl_set_parent(NULL, root_table);
1846 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1847         {
1848                 int err;
1849                 err = sysctl_check_table(current->nsproxy, root_table);
1850         }
1851 #endif
1852         return 0;
1853 }
1854
1855 core_initcall(sysctl_init);
1856
1857 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1858                                       struct ctl_table *table)
1859 {
1860         struct ctl_table *p;
1861         const char *s = branch->procname;
1862
1863         /* branch should have named subdirectory as its first element */
1864         if (!s || !branch->child)
1865                 return NULL;
1866
1867         /* ... and nothing else */
1868         if (branch[1].procname || branch[1].ctl_name)
1869                 return NULL;
1870
1871         /* table should contain subdirectory with the same name */
1872         for (p = table; p->procname || p->ctl_name; p++) {
1873                 if (!p->child)
1874                         continue;
1875                 if (p->procname && strcmp(p->procname, s) == 0)
1876                         return p;
1877         }
1878         return NULL;
1879 }
1880
1881 /* see if attaching q to p would be an improvement */
1882 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1883 {
1884         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1885         struct ctl_table *next;
1886         int is_better = 0;
1887         int not_in_parent = !p->attached_by;
1888
1889         while ((next = is_branch_in(by, to)) != NULL) {
1890                 if (by == q->attached_by)
1891                         is_better = 1;
1892                 if (to == p->attached_by)
1893                         not_in_parent = 1;
1894                 by = by->child;
1895                 to = next->child;
1896         }
1897
1898         if (is_better && not_in_parent) {
1899                 q->attached_by = by;
1900                 q->attached_to = to;
1901                 q->parent = p;
1902         }
1903 }
1904
1905 /**
1906  * __register_sysctl_paths - register a sysctl hierarchy
1907  * @root: List of sysctl headers to register on
1908  * @namespaces: Data to compute which lists of sysctl entries are visible
1909  * @path: The path to the directory the sysctl table is in.
1910  * @table: the top-level table structure
1911  *
1912  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1913  * array. A completely 0 filled entry terminates the table.
1914  *
1915  * The members of the &struct ctl_table structure are used as follows:
1916  *
1917  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1918  *            must be unique within that level of sysctl
1919  *
1920  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1921  *            enter a sysctl file
1922  *
1923  * data - a pointer to data for use by proc_handler
1924  *
1925  * maxlen - the maximum size in bytes of the data
1926  *
1927  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1928  *
1929  * child - a pointer to the child sysctl table if this entry is a directory, or
1930  *         %NULL.
1931  *
1932  * proc_handler - the text handler routine (described below)
1933  *
1934  * strategy - the strategy routine (described below)
1935  *
1936  * de - for internal use by the sysctl routines
1937  *
1938  * extra1, extra2 - extra pointers usable by the proc handler routines
1939  *
1940  * Leaf nodes in the sysctl tree will be represented by a single file
1941  * under /proc; non-leaf nodes will be represented by directories.
1942  *
1943  * sysctl(2) can automatically manage read and write requests through
1944  * the sysctl table.  The data and maxlen fields of the ctl_table
1945  * struct enable minimal validation of the values being written to be
1946  * performed, and the mode field allows minimal authentication.
1947  *
1948  * More sophisticated management can be enabled by the provision of a
1949  * strategy routine with the table entry.  This will be called before
1950  * any automatic read or write of the data is performed.
1951  *
1952  * The strategy routine may return
1953  *
1954  * < 0 - Error occurred (error is passed to user process)
1955  *
1956  * 0   - OK - proceed with automatic read or write.
1957  *
1958  * > 0 - OK - read or write has been done by the strategy routine, so
1959  *       return immediately.
1960  *
1961  * There must be a proc_handler routine for any terminal nodes
1962  * mirrored under /proc/sys (non-terminals are handled by a built-in
1963  * directory handler).  Several default handlers are available to
1964  * cover common cases -
1965  *
1966  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1967  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1968  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1969  *
1970  * It is the handler's job to read the input buffer from user memory
1971  * and process it. The handler should return 0 on success.
1972  *
1973  * This routine returns %NULL on a failure to register, and a pointer
1974  * to the table header on success.
1975  */
1976 struct ctl_table_header *__register_sysctl_paths(
1977         struct ctl_table_root *root,
1978         struct nsproxy *namespaces,
1979         const struct ctl_path *path, struct ctl_table *table)
1980 {
1981         struct ctl_table_header *header;
1982         struct ctl_table *new, **prevp;
1983         unsigned int n, npath;
1984         struct ctl_table_set *set;
1985
1986         /* Count the path components */
1987         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1988                 ;
1989
1990         /*
1991          * For each path component, allocate a 2-element ctl_table array.
1992          * The first array element will be filled with the sysctl entry
1993          * for this, the second will be the sentinel (ctl_name == 0).
1994          *
1995          * We allocate everything in one go so that we don't have to
1996          * worry about freeing additional memory in unregister_sysctl_table.
1997          */
1998         header = kzalloc(sizeof(struct ctl_table_header) +
1999                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2000         if (!header)
2001                 return NULL;
2002
2003         new = (struct ctl_table *) (header + 1);
2004
2005         /* Now connect the dots */
2006         prevp = &header->ctl_table;
2007         for (n = 0; n < npath; ++n, ++path) {
2008                 /* Copy the procname */
2009                 new->procname = path->procname;
2010                 new->ctl_name = path->ctl_name;
2011                 new->mode     = 0555;
2012
2013                 *prevp = new;
2014                 prevp = &new->child;
2015
2016                 new += 2;
2017         }
2018         *prevp = table;
2019         header->ctl_table_arg = table;
2020
2021         INIT_LIST_HEAD(&header->ctl_entry);
2022         header->used = 0;
2023         header->unregistering = NULL;
2024         header->root = root;
2025         sysctl_set_parent(NULL, header->ctl_table);
2026         header->count = 1;
2027 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2028         if (sysctl_check_table(namespaces, header->ctl_table)) {
2029                 kfree(header);
2030                 return NULL;
2031         }
2032 #endif
2033         spin_lock(&sysctl_lock);
2034         header->set = lookup_header_set(root, namespaces);
2035         header->attached_by = header->ctl_table;
2036         header->attached_to = root_table;
2037         header->parent = &root_table_header;
2038         for (set = header->set; set; set = set->parent) {
2039                 struct ctl_table_header *p;
2040                 list_for_each_entry(p, &set->list, ctl_entry) {
2041                         if (p->unregistering)
2042                                 continue;
2043                         try_attach(p, header);
2044                 }
2045         }
2046         header->parent->count++;
2047         list_add_tail(&header->ctl_entry, &header->set->list);
2048         spin_unlock(&sysctl_lock);
2049
2050         return header;
2051 }
2052
2053 /**
2054  * register_sysctl_table_path - register a sysctl table hierarchy
2055  * @path: The path to the directory the sysctl table is in.
2056  * @table: the top-level table structure
2057  *
2058  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2059  * array. A completely 0 filled entry terminates the table.
2060  *
2061  * See __register_sysctl_paths for more details.
2062  */
2063 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2064                                                 struct ctl_table *table)
2065 {
2066         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2067                                         path, table);
2068 }
2069
2070 /**
2071  * register_sysctl_table - register a sysctl table hierarchy
2072  * @table: the top-level table structure
2073  *
2074  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2075  * array. A completely 0 filled entry terminates the table.
2076  *
2077  * See register_sysctl_paths for more details.
2078  */
2079 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2080 {
2081         static const struct ctl_path null_path[] = { {} };
2082
2083         return register_sysctl_paths(null_path, table);
2084 }
2085
2086 /**
2087  * unregister_sysctl_table - unregister a sysctl table hierarchy
2088  * @header: the header returned from register_sysctl_table
2089  *
2090  * Unregisters the sysctl table and all children. proc entries may not
2091  * actually be removed until they are no longer used by anyone.
2092  */
2093 void unregister_sysctl_table(struct ctl_table_header * header)
2094 {
2095         might_sleep();
2096
2097         if (header == NULL)
2098                 return;
2099
2100         spin_lock(&sysctl_lock);
2101         start_unregistering(header);
2102         if (!--header->parent->count) {
2103                 WARN_ON(1);
2104                 kfree(header->parent);
2105         }
2106         if (!--header->count)
2107                 kfree(header);
2108         spin_unlock(&sysctl_lock);
2109 }
2110
2111 int sysctl_is_seen(struct ctl_table_header *p)
2112 {
2113         struct ctl_table_set *set = p->set;
2114         int res;
2115         spin_lock(&sysctl_lock);
2116         if (p->unregistering)
2117                 res = 0;
2118         else if (!set->is_seen)
2119                 res = 1;
2120         else
2121                 res = set->is_seen(set);
2122         spin_unlock(&sysctl_lock);
2123         return res;
2124 }
2125
2126 void setup_sysctl_set(struct ctl_table_set *p,
2127         struct ctl_table_set *parent,
2128         int (*is_seen)(struct ctl_table_set *))
2129 {
2130         INIT_LIST_HEAD(&p->list);
2131         p->parent = parent ? parent : &sysctl_table_root.default_set;
2132         p->is_seen = is_seen;
2133 }
2134
2135 #else /* !CONFIG_SYSCTL */
2136 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2137 {
2138         return NULL;
2139 }
2140
2141 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2142                                                     struct ctl_table *table)
2143 {
2144         return NULL;
2145 }
2146
2147 void unregister_sysctl_table(struct ctl_table_header * table)
2148 {
2149 }
2150
2151 void setup_sysctl_set(struct ctl_table_set *p,
2152         struct ctl_table_set *parent,
2153         int (*is_seen)(struct ctl_table_set *))
2154 {
2155 }
2156
2157 void sysctl_head_put(struct ctl_table_header *head)
2158 {
2159 }
2160
2161 #endif /* CONFIG_SYSCTL */
2162
2163 /*
2164  * /proc/sys support
2165  */
2166
2167 #ifdef CONFIG_PROC_SYSCTL
2168
2169 static int _proc_do_string(void* data, int maxlen, int write,
2170                            struct file *filp, void __user *buffer,
2171                            size_t *lenp, loff_t *ppos)
2172 {
2173         size_t len;
2174         char __user *p;
2175         char c;
2176
2177         if (!data || !maxlen || !*lenp) {
2178                 *lenp = 0;
2179                 return 0;
2180         }
2181
2182         if (write) {
2183                 len = 0;
2184                 p = buffer;
2185                 while (len < *lenp) {
2186                         if (get_user(c, p++))
2187                                 return -EFAULT;
2188                         if (c == 0 || c == '\n')
2189                                 break;
2190                         len++;
2191                 }
2192                 if (len >= maxlen)
2193                         len = maxlen-1;
2194                 if(copy_from_user(data, buffer, len))
2195                         return -EFAULT;
2196                 ((char *) data)[len] = 0;
2197                 *ppos += *lenp;
2198         } else {
2199                 len = strlen(data);
2200                 if (len > maxlen)
2201                         len = maxlen;
2202
2203                 if (*ppos > len) {
2204                         *lenp = 0;
2205                         return 0;
2206                 }
2207
2208                 data += *ppos;
2209                 len  -= *ppos;
2210
2211                 if (len > *lenp)
2212                         len = *lenp;
2213                 if (len)
2214                         if(copy_to_user(buffer, data, len))
2215                                 return -EFAULT;
2216                 if (len < *lenp) {
2217                         if(put_user('\n', ((char __user *) buffer) + len))
2218                                 return -EFAULT;
2219                         len++;
2220                 }
2221                 *lenp = len;
2222                 *ppos += len;
2223         }
2224         return 0;
2225 }
2226
2227 /**
2228  * proc_dostring - read a string sysctl
2229  * @table: the sysctl table
2230  * @write: %TRUE if this is a write to the sysctl file
2231  * @filp: the file structure
2232  * @buffer: the user buffer
2233  * @lenp: the size of the user buffer
2234  * @ppos: file position
2235  *
2236  * Reads/writes a string from/to the user buffer. If the kernel
2237  * buffer provided is not large enough to hold the string, the
2238  * string is truncated. The copied string is %NULL-terminated.
2239  * If the string is being read by the user process, it is copied
2240  * and a newline '\n' is added. It is truncated if the buffer is
2241  * not large enough.
2242  *
2243  * Returns 0 on success.
2244  */
2245 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2246                   void __user *buffer, size_t *lenp, loff_t *ppos)
2247 {
2248         return _proc_do_string(table->data, table->maxlen, write, filp,
2249                                buffer, lenp, ppos);
2250 }
2251
2252
2253 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2254                                  int *valp,
2255                                  int write, void *data)
2256 {
2257         if (write) {
2258                 *valp = *negp ? -*lvalp : *lvalp;
2259         } else {
2260                 int val = *valp;
2261                 if (val < 0) {
2262                         *negp = -1;
2263                         *lvalp = (unsigned long)-val;
2264                 } else {
2265                         *negp = 0;
2266                         *lvalp = (unsigned long)val;
2267                 }
2268         }
2269         return 0;
2270 }
2271
2272 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2273                   int write, struct file *filp, void __user *buffer,
2274                   size_t *lenp, loff_t *ppos,
2275                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2276                               int write, void *data),
2277                   void *data)
2278 {
2279 #define TMPBUFLEN 21
2280         int *i, vleft, first=1, neg, val;
2281         unsigned long lval;
2282         size_t left, len;
2283
2284         char buf[TMPBUFLEN], *p;
2285         char __user *s = buffer;
2286
2287         if (!tbl_data || !table->maxlen || !*lenp ||
2288             (*ppos && !write)) {
2289                 *lenp = 0;
2290                 return 0;
2291         }
2292
2293         i = (int *) tbl_data;
2294         vleft = table->maxlen / sizeof(*i);
2295         left = *lenp;
2296
2297         if (!conv)
2298                 conv = do_proc_dointvec_conv;
2299
2300         for (; left && vleft--; i++, first=0) {
2301                 if (write) {
2302                         while (left) {
2303                                 char c;
2304                                 if (get_user(c, s))
2305                                         return -EFAULT;
2306                                 if (!isspace(c))
2307                                         break;
2308                                 left--;
2309                                 s++;
2310                         }
2311                         if (!left)
2312                                 break;
2313                         neg = 0;
2314                         len = left;
2315                         if (len > sizeof(buf) - 1)
2316                                 len = sizeof(buf) - 1;
2317                         if (copy_from_user(buf, s, len))
2318                                 return -EFAULT;
2319                         buf[len] = 0;
2320                         p = buf;
2321                         if (*p == '-' && left > 1) {
2322                                 neg = 1;
2323                                 p++;
2324                         }
2325                         if (*p < '0' || *p > '9')
2326                                 break;
2327
2328                         lval = simple_strtoul(p, &p, 0);
2329
2330                         len = p-buf;
2331                         if ((len < left) && *p && !isspace(*p))
2332                                 break;
2333                         if (neg)
2334                                 val = -val;
2335                         s += len;
2336                         left -= len;
2337
2338                         if (conv(&neg, &lval, i, 1, data))
2339                                 break;
2340                 } else {
2341                         p = buf;
2342                         if (!first)
2343                                 *p++ = '\t';
2344
2345                         if (conv(&neg, &lval, i, 0, data))
2346                                 break;
2347
2348                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2349                         len = strlen(buf);
2350                         if (len > left)
2351                                 len = left;
2352                         if(copy_to_user(s, buf, len))
2353                                 return -EFAULT;
2354                         left -= len;
2355                         s += len;
2356                 }
2357         }
2358
2359         if (!write && !first && left) {
2360                 if(put_user('\n', s))
2361                         return -EFAULT;
2362                 left--, s++;
2363         }
2364         if (write) {
2365                 while (left) {
2366                         char c;
2367                         if (get_user(c, s++))
2368                                 return -EFAULT;
2369                         if (!isspace(c))
2370                                 break;
2371                         left--;
2372                 }
2373         }
2374         if (write && first)
2375                 return -EINVAL;
2376         *lenp -= left;
2377         *ppos += *lenp;
2378         return 0;
2379 #undef TMPBUFLEN
2380 }
2381
2382 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2383                   void __user *buffer, size_t *lenp, loff_t *ppos,
2384                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2385                               int write, void *data),
2386                   void *data)
2387 {
2388         return __do_proc_dointvec(table->data, table, write, filp,
2389                         buffer, lenp, ppos, conv, data);
2390 }
2391
2392 /**
2393  * proc_dointvec - read a vector of integers
2394  * @table: the sysctl table
2395  * @write: %TRUE if this is a write to the sysctl file
2396  * @filp: the file structure
2397  * @buffer: the user buffer
2398  * @lenp: the size of the user buffer
2399  * @ppos: file position
2400  *
2401  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2402  * values from/to the user buffer, treated as an ASCII string.
2403  *
2404  * Returns 0 on success.
2405  */
2406 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2407                      void __user *buffer, size_t *lenp, loff_t *ppos)
2408 {
2409     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2410                             NULL,NULL);
2411 }
2412
2413 /*
2414  * Taint values can only be increased
2415  * This means we can safely use a temporary.
2416  */
2417 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2418                                void __user *buffer, size_t *lenp, loff_t *ppos)
2419 {
2420         struct ctl_table t;
2421         unsigned long tmptaint = get_taint();
2422         int err;
2423
2424         if (write && !capable(CAP_SYS_ADMIN))
2425                 return -EPERM;
2426
2427         t = *table;
2428         t.data = &tmptaint;
2429         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2430         if (err < 0)
2431                 return err;
2432
2433         if (write) {
2434                 /*
2435                  * Poor man's atomic or. Not worth adding a primitive
2436                  * to everyone's atomic.h for this
2437                  */
2438                 int i;
2439                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2440                         if ((tmptaint >> i) & 1)
2441                                 add_taint(i);
2442                 }
2443         }
2444
2445         return err;
2446 }
2447
2448 struct do_proc_dointvec_minmax_conv_param {
2449         int *min;
2450         int *max;
2451 };
2452
2453 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2454                                         int *valp,
2455                                         int write, void *data)
2456 {
2457         struct do_proc_dointvec_minmax_conv_param *param = data;
2458         if (write) {
2459                 int val = *negp ? -*lvalp : *lvalp;
2460                 if ((param->min && *param->min > val) ||
2461                     (param->max && *param->max < val))
2462                         return -EINVAL;
2463                 *valp = val;
2464         } else {
2465                 int val = *valp;
2466                 if (val < 0) {
2467                         *negp = -1;
2468                         *lvalp = (unsigned long)-val;
2469                 } else {
2470                         *negp = 0;
2471                         *lvalp = (unsigned long)val;
2472                 }
2473         }
2474         return 0;
2475 }
2476
2477 /**
2478  * proc_dointvec_minmax - read a vector of integers with min/max values
2479  * @table: the sysctl table
2480  * @write: %TRUE if this is a write to the sysctl file
2481  * @filp: the file structure
2482  * @buffer: the user buffer
2483  * @lenp: the size of the user buffer
2484  * @ppos: file position
2485  *
2486  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2487  * values from/to the user buffer, treated as an ASCII string.
2488  *
2489  * This routine will ensure the values are within the range specified by
2490  * table->extra1 (min) and table->extra2 (max).
2491  *
2492  * Returns 0 on success.
2493  */
2494 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2495                   void __user *buffer, size_t *lenp, loff_t *ppos)
2496 {
2497         struct do_proc_dointvec_minmax_conv_param param = {
2498                 .min = (int *) table->extra1,
2499                 .max = (int *) table->extra2,
2500         };
2501         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2502                                 do_proc_dointvec_minmax_conv, &param);
2503 }
2504
2505 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2506                                      struct file *filp,
2507                                      void __user *buffer,
2508                                      size_t *lenp, loff_t *ppos,
2509                                      unsigned long convmul,
2510                                      unsigned long convdiv)
2511 {
2512 #define TMPBUFLEN 21
2513         unsigned long *i, *min, *max, val;
2514         int vleft, first=1, neg;
2515         size_t len, left;
2516         char buf[TMPBUFLEN], *p;
2517         char __user *s = buffer;
2518
2519         if (!data || !table->maxlen || !*lenp ||
2520             (*ppos && !write)) {
2521                 *lenp = 0;
2522                 return 0;
2523         }
2524
2525         i = (unsigned long *) data;
2526         min = (unsigned long *) table->extra1;
2527         max = (unsigned long *) table->extra2;
2528         vleft = table->maxlen / sizeof(unsigned long);
2529         left = *lenp;
2530
2531         for (; left && vleft--; i++, min++, max++, first=0) {
2532                 if (write) {
2533                         while (left) {
2534                                 char c;
2535                                 if (get_user(c, s))
2536                                         return -EFAULT;
2537                                 if (!isspace(c))
2538                                         break;
2539                                 left--;
2540                                 s++;
2541                         }
2542                         if (!left)
2543                                 break;
2544                         neg = 0;
2545                         len = left;
2546                         if (len > TMPBUFLEN-1)
2547                                 len = TMPBUFLEN-1;
2548                         if (copy_from_user(buf, s, len))
2549                                 return -EFAULT;
2550                         buf[len] = 0;
2551                         p = buf;
2552                         if (*p == '-' && left > 1) {
2553                                 neg = 1;
2554                                 p++;
2555                         }
2556                         if (*p < '0' || *p > '9')
2557                                 break;
2558                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2559                         len = p-buf;
2560                         if ((len < left) && *p && !isspace(*p))
2561                                 break;
2562                         if (neg)
2563                                 val = -val;
2564                         s += len;
2565                         left -= len;
2566
2567                         if(neg)
2568                                 continue;
2569                         if ((min && val < *min) || (max && val > *max))
2570                                 continue;
2571                         *i = val;
2572                 } else {
2573                         p = buf;
2574                         if (!first)
2575                                 *p++ = '\t';
2576                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2577                         len = strlen(buf);
2578                         if (len > left)
2579                                 len = left;
2580                         if(copy_to_user(s, buf, len))
2581                                 return -EFAULT;
2582                         left -= len;
2583                         s += len;
2584                 }
2585         }
2586
2587         if (!write && !first && left) {
2588                 if(put_user('\n', s))
2589                         return -EFAULT;
2590                 left--, s++;
2591         }
2592         if (write) {
2593                 while (left) {
2594                         char c;
2595                         if (get_user(c, s++))
2596                                 return -EFAULT;
2597                         if (!isspace(c))
2598                                 break;
2599                         left--;
2600                 }
2601         }
2602         if (write && first)
2603                 return -EINVAL;
2604         *lenp -= left;
2605         *ppos += *lenp;
2606         return 0;
2607 #undef TMPBUFLEN
2608 }
2609
2610 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2611                                      struct file *filp,
2612                                      void __user *buffer,
2613                                      size_t *lenp, loff_t *ppos,
2614                                      unsigned long convmul,
2615                                      unsigned long convdiv)
2616 {
2617         return __do_proc_doulongvec_minmax(table->data, table, write,
2618                         filp, buffer, lenp, ppos, convmul, convdiv);
2619 }
2620
2621 /**
2622  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2623  * @table: the sysctl table
2624  * @write: %TRUE if this is a write to the sysctl file
2625  * @filp: the file structure
2626  * @buffer: the user buffer
2627  * @lenp: the size of the user buffer
2628  * @ppos: file position
2629  *
2630  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2631  * values from/to the user buffer, treated as an ASCII string.
2632  *
2633  * This routine will ensure the values are within the range specified by
2634  * table->extra1 (min) and table->extra2 (max).
2635  *
2636  * Returns 0 on success.
2637  */
2638 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2639                            void __user *buffer, size_t *lenp, loff_t *ppos)
2640 {
2641     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2642 }
2643
2644 /**
2645  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2646  * @table: the sysctl table
2647  * @write: %TRUE if this is a write to the sysctl file
2648  * @filp: the file structure
2649  * @buffer: the user buffer
2650  * @lenp: the size of the user buffer
2651  * @ppos: file position
2652  *
2653  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2654  * values from/to the user buffer, treated as an ASCII string. The values
2655  * are treated as milliseconds, and converted to jiffies when they are stored.
2656  *
2657  * This routine will ensure the values are within the range specified by
2658  * table->extra1 (min) and table->extra2 (max).
2659  *
2660  * Returns 0 on success.
2661  */
2662 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2663                                       struct file *filp,
2664                                       void __user *buffer,
2665                                       size_t *lenp, loff_t *ppos)
2666 {
2667     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2668                                      lenp, ppos, HZ, 1000l);
2669 }
2670
2671
2672 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2673                                          int *valp,
2674                                          int write, void *data)
2675 {
2676         if (write) {
2677                 if (*lvalp > LONG_MAX / HZ)
2678                         return 1;
2679                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2680         } else {
2681                 int val = *valp;
2682                 unsigned long lval;
2683                 if (val < 0) {
2684                         *negp = -1;
2685                         lval = (unsigned long)-val;
2686                 } else {
2687                         *negp = 0;
2688                         lval = (unsigned long)val;
2689                 }
2690                 *lvalp = lval / HZ;
2691         }
2692         return 0;
2693 }
2694
2695 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2696                                                 int *valp,
2697                                                 int write, void *data)
2698 {
2699         if (write) {
2700                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2701                         return 1;
2702                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2703         } else {
2704                 int val = *valp;
2705                 unsigned long lval;
2706                 if (val < 0) {
2707                         *negp = -1;
2708                         lval = (unsigned long)-val;
2709                 } else {
2710                         *negp = 0;
2711                         lval = (unsigned long)val;
2712                 }
2713                 *lvalp = jiffies_to_clock_t(lval);
2714         }
2715         return 0;
2716 }
2717
2718 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2719                                             int *valp,
2720                                             int write, void *data)
2721 {
2722         if (write) {
2723                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2724         } else {
2725                 int val = *valp;
2726                 unsigned long lval;
2727                 if (val < 0) {
2728                         *negp = -1;
2729                         lval = (unsigned long)-val;
2730                 } else {
2731                         *negp = 0;
2732                         lval = (unsigned long)val;
2733                 }
2734                 *lvalp = jiffies_to_msecs(lval);
2735         }
2736         return 0;
2737 }
2738
2739 /**
2740  * proc_dointvec_jiffies - read a vector of integers as seconds
2741  * @table: the sysctl table
2742  * @write: %TRUE if this is a write to the sysctl file
2743  * @filp: the file structure
2744  * @buffer: the user buffer
2745  * @lenp: the size of the user buffer
2746  * @ppos: file position
2747  *
2748  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2749  * values from/to the user buffer, treated as an ASCII string.
2750  * The values read are assumed to be in seconds, and are converted into
2751  * jiffies.
2752  *
2753  * Returns 0 on success.
2754  */
2755 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2756                           void __user *buffer, size_t *lenp, loff_t *ppos)
2757 {
2758     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2759                             do_proc_dointvec_jiffies_conv,NULL);
2760 }
2761
2762 /**
2763  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2764  * @table: the sysctl table
2765  * @write: %TRUE if this is a write to the sysctl file
2766  * @filp: the file structure
2767  * @buffer: the user buffer
2768  * @lenp: the size of the user buffer
2769  * @ppos: pointer to the file position
2770  *
2771  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2772  * values from/to the user buffer, treated as an ASCII string.
2773  * The values read are assumed to be in 1/USER_HZ seconds, and
2774  * are converted into jiffies.
2775  *
2776  * Returns 0 on success.
2777  */
2778 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2779                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2780 {
2781     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2782                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2783 }
2784
2785 /**
2786  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2787  * @table: the sysctl table
2788  * @write: %TRUE if this is a write to the sysctl file
2789  * @filp: the file structure
2790  * @buffer: the user buffer
2791  * @lenp: the size of the user buffer
2792  * @ppos: file position
2793  * @ppos: the current position in the file
2794  *
2795  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2796  * values from/to the user buffer, treated as an ASCII string.
2797  * The values read are assumed to be in 1/1000 seconds, and
2798  * are converted into jiffies.
2799  *
2800  * Returns 0 on success.
2801  */
2802 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2803                              void __user *buffer, size_t *lenp, loff_t *ppos)
2804 {
2805         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2806                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2807 }
2808
2809 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2810                            void __user *buffer, size_t *lenp, loff_t *ppos)
2811 {
2812         struct pid *new_pid;
2813         pid_t tmp;
2814         int r;
2815
2816         tmp = pid_vnr(cad_pid);
2817
2818         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2819                                lenp, ppos, NULL, NULL);
2820         if (r || !write)
2821                 return r;
2822
2823         new_pid = find_get_pid(tmp);
2824         if (!new_pid)
2825                 return -ESRCH;
2826
2827         put_pid(xchg(&cad_pid, new_pid));
2828         return 0;
2829 }
2830
2831 #else /* CONFIG_PROC_FS */
2832
2833 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2834                   void __user *buffer, size_t *lenp, loff_t *ppos)
2835 {
2836         return -ENOSYS;
2837 }
2838
2839 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2840                   void __user *buffer, size_t *lenp, loff_t *ppos)
2841 {
2842         return -ENOSYS;
2843 }
2844
2845 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2846                     void __user *buffer, size_t *lenp, loff_t *ppos)
2847 {
2848         return -ENOSYS;
2849 }
2850
2851 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2852                     void __user *buffer, size_t *lenp, loff_t *ppos)
2853 {
2854         return -ENOSYS;
2855 }
2856
2857 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2858                     void __user *buffer, size_t *lenp, loff_t *ppos)
2859 {
2860         return -ENOSYS;
2861 }
2862
2863 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2864                              void __user *buffer, size_t *lenp, loff_t *ppos)
2865 {
2866         return -ENOSYS;
2867 }
2868
2869 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2870                     void __user *buffer, size_t *lenp, loff_t *ppos)
2871 {
2872         return -ENOSYS;
2873 }
2874
2875 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2876                                       struct file *filp,
2877                                       void __user *buffer,
2878                                       size_t *lenp, loff_t *ppos)
2879 {
2880     return -ENOSYS;
2881 }
2882
2883
2884 #endif /* CONFIG_PROC_FS */
2885
2886
2887 #ifdef CONFIG_SYSCTL_SYSCALL
2888 /*
2889  * General sysctl support routines
2890  */
2891
2892 /* The generic sysctl data routine (used if no strategy routine supplied) */
2893 int sysctl_data(struct ctl_table *table,
2894                 void __user *oldval, size_t __user *oldlenp,
2895                 void __user *newval, size_t newlen)
2896 {
2897         size_t len;
2898
2899         /* Get out of I don't have a variable */
2900         if (!table->data || !table->maxlen)
2901                 return -ENOTDIR;
2902
2903         if (oldval && oldlenp) {
2904                 if (get_user(len, oldlenp))
2905                         return -EFAULT;
2906                 if (len) {
2907                         if (len > table->maxlen)
2908                                 len = table->maxlen;
2909                         if (copy_to_user(oldval, table->data, len))
2910                                 return -EFAULT;
2911                         if (put_user(len, oldlenp))
2912                                 return -EFAULT;
2913                 }
2914         }
2915
2916         if (newval && newlen) {
2917                 if (newlen > table->maxlen)
2918                         newlen = table->maxlen;
2919
2920                 if (copy_from_user(table->data, newval, newlen))
2921                         return -EFAULT;
2922         }
2923         return 1;
2924 }
2925
2926 /* The generic string strategy routine: */
2927 int sysctl_string(struct ctl_table *table,
2928                   void __user *oldval, size_t __user *oldlenp,
2929                   void __user *newval, size_t newlen)
2930 {
2931         if (!table->data || !table->maxlen)
2932                 return -ENOTDIR;
2933
2934         if (oldval && oldlenp) {
2935                 size_t bufsize;
2936                 if (get_user(bufsize, oldlenp))
2937                         return -EFAULT;
2938                 if (bufsize) {
2939                         size_t len = strlen(table->data), copied;
2940
2941                         /* This shouldn't trigger for a well-formed sysctl */
2942                         if (len > table->maxlen)
2943                                 len = table->maxlen;
2944
2945                         /* Copy up to a max of bufsize-1 bytes of the string */
2946                         copied = (len >= bufsize) ? bufsize - 1 : len;
2947
2948                         if (copy_to_user(oldval, table->data, copied) ||
2949                             put_user(0, (char __user *)(oldval + copied)))
2950                                 return -EFAULT;
2951                         if (put_user(len, oldlenp))
2952                                 return -EFAULT;
2953                 }
2954         }
2955         if (newval && newlen) {
2956                 size_t len = newlen;
2957                 if (len > table->maxlen)
2958                         len = table->maxlen;
2959                 if(copy_from_user(table->data, newval, len))
2960                         return -EFAULT;
2961                 if (len == table->maxlen)
2962                         len--;
2963                 ((char *) table->data)[len] = 0;
2964         }
2965         return 1;
2966 }
2967
2968 /*
2969  * This function makes sure that all of the integers in the vector
2970  * are between the minimum and maximum values given in the arrays
2971  * table->extra1 and table->extra2, respectively.
2972  */
2973 int sysctl_intvec(struct ctl_table *table,
2974                 void __user *oldval, size_t __user *oldlenp,
2975                 void __user *newval, size_t newlen)
2976 {
2977
2978         if (newval && newlen) {
2979                 int __user *vec = (int __user *) newval;
2980                 int *min = (int *) table->extra1;
2981                 int *max = (int *) table->extra2;
2982                 size_t length;
2983                 int i;
2984
2985                 if (newlen % sizeof(int) != 0)
2986                         return -EINVAL;
2987
2988                 if (!table->extra1 && !table->extra2)
2989                         return 0;
2990
2991                 if (newlen > table->maxlen)
2992                         newlen = table->maxlen;
2993                 length = newlen / sizeof(int);
2994
2995                 for (i = 0; i < length; i++) {
2996                         int value;
2997                         if (get_user(value, vec + i))
2998                                 return -EFAULT;
2999                         if (min && value < min[i])
3000                                 return -EINVAL;
3001                         if (max && value > max[i])
3002                                 return -EINVAL;
3003                 }
3004         }
3005         return 0;
3006 }
3007
3008 /* Strategy function to convert jiffies to seconds */
3009 int sysctl_jiffies(struct ctl_table *table,
3010                 void __user *oldval, size_t __user *oldlenp,
3011                 void __user *newval, size_t newlen)
3012 {
3013         if (oldval && oldlenp) {
3014                 size_t olen;
3015
3016                 if (get_user(olen, oldlenp))
3017                         return -EFAULT;
3018                 if (olen) {
3019                         int val;
3020
3021                         if (olen < sizeof(int))
3022                                 return -EINVAL;
3023
3024                         val = *(int *)(table->data) / HZ;
3025                         if (put_user(val, (int __user *)oldval))
3026                                 return -EFAULT;
3027                         if (put_user(sizeof(int), oldlenp))
3028                                 return -EFAULT;
3029                 }
3030         }
3031         if (newval && newlen) {
3032                 int new;
3033                 if (newlen != sizeof(int))
3034                         return -EINVAL;
3035                 if (get_user(new, (int __user *)newval))
3036                         return -EFAULT;
3037                 *(int *)(table->data) = new*HZ;
3038         }
3039         return 1;
3040 }
3041
3042 /* Strategy function to convert jiffies to seconds */
3043 int sysctl_ms_jiffies(struct ctl_table *table,
3044                 void __user *oldval, size_t __user *oldlenp,
3045                 void __user *newval, size_t newlen)
3046 {
3047         if (oldval && oldlenp) {
3048                 size_t olen;
3049
3050                 if (get_user(olen, oldlenp))
3051                         return -EFAULT;
3052                 if (olen) {
3053                         int val;
3054
3055                         if (olen < sizeof(int))
3056                                 return -EINVAL;
3057
3058                         val = jiffies_to_msecs(*(int *)(table->data));
3059                         if (put_user(val, (int __user *)oldval))
3060                                 return -EFAULT;
3061                         if (put_user(sizeof(int), oldlenp))
3062                                 return -EFAULT;
3063                 }
3064         }
3065         if (newval && newlen) {
3066                 int new;
3067                 if (newlen != sizeof(int))
3068                         return -EINVAL;
3069                 if (get_user(new, (int __user *)newval))
3070                         return -EFAULT;
3071                 *(int *)(table->data) = msecs_to_jiffies(new);
3072         }
3073         return 1;
3074 }
3075
3076
3077
3078 #else /* CONFIG_SYSCTL_SYSCALL */
3079
3080
3081 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3082 {
3083         struct __sysctl_args tmp;
3084         int error;
3085
3086         if (copy_from_user(&tmp, args, sizeof(tmp)))
3087                 return -EFAULT;
3088
3089         error = deprecated_sysctl_warning(&tmp);
3090
3091         /* If no error reading the parameters then just -ENOSYS ... */
3092         if (!error)
3093                 error = -ENOSYS;
3094
3095         return error;
3096 }
3097
3098 int sysctl_data(struct ctl_table *table,
3099                   void __user *oldval, size_t __user *oldlenp,
3100                   void __user *newval, size_t newlen)
3101 {
3102         return -ENOSYS;
3103 }
3104
3105 int sysctl_string(struct ctl_table *table,
3106                   void __user *oldval, size_t __user *oldlenp,
3107                   void __user *newval, size_t newlen)
3108 {
3109         return -ENOSYS;
3110 }
3111
3112 int sysctl_intvec(struct ctl_table *table,
3113                 void __user *oldval, size_t __user *oldlenp,
3114                 void __user *newval, size_t newlen)
3115 {
3116         return -ENOSYS;
3117 }
3118
3119 int sysctl_jiffies(struct ctl_table *table,
3120                 void __user *oldval, size_t __user *oldlenp,
3121                 void __user *newval, size_t newlen)
3122 {
3123         return -ENOSYS;
3124 }
3125
3126 int sysctl_ms_jiffies(struct ctl_table *table,
3127                 void __user *oldval, size_t __user *oldlenp,
3128                 void __user *newval, size_t newlen)
3129 {
3130         return -ENOSYS;
3131 }
3132
3133 #endif /* CONFIG_SYSCTL_SYSCALL */
3134
3135 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3136 {
3137         static int msg_count;
3138         int name[CTL_MAXNAME];
3139         int i;
3140
3141         /* Check args->nlen. */
3142         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3143                 return -ENOTDIR;
3144
3145         /* Read in the sysctl name for better debug message logging */
3146         for (i = 0; i < args->nlen; i++)
3147                 if (get_user(name[i], args->name + i))
3148                         return -EFAULT;
3149
3150         /* Ignore accesses to kernel.version */
3151         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3152                 return 0;
3153
3154         if (msg_count < 5) {
3155                 msg_count++;
3156                 printk(KERN_INFO
3157                         "warning: process `%s' used the deprecated sysctl "
3158                         "system call with ", current->comm);
3159                 for (i = 0; i < args->nlen; i++)
3160                         printk("%d.", name[i]);
3161                 printk("\n");
3162         }
3163         return 0;
3164 }
3165
3166 /*
3167  * No sense putting this after each symbol definition, twice,
3168  * exception granted :-)
3169  */
3170 EXPORT_SYMBOL(proc_dointvec);
3171 EXPORT_SYMBOL(proc_dointvec_jiffies);
3172 EXPORT_SYMBOL(proc_dointvec_minmax);
3173 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3174 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3175 EXPORT_SYMBOL(proc_dostring);
3176 EXPORT_SYMBOL(proc_doulongvec_minmax);
3177 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3178 EXPORT_SYMBOL(register_sysctl_table);
3179 EXPORT_SYMBOL(register_sysctl_paths);
3180 EXPORT_SYMBOL(sysctl_intvec);
3181 EXPORT_SYMBOL(sysctl_jiffies);
3182 EXPORT_SYMBOL(sysctl_ms_jiffies);
3183 EXPORT_SYMBOL(sysctl_string);
3184 EXPORT_SYMBOL(sysctl_data);
3185 EXPORT_SYMBOL(unregister_sysctl_table);