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