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