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

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