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/capability.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/capability.h>
  31 #include <linux/smp_lock.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/security.h>
  41 #include <linux/initrd.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/nfs_fs.h>
  47 #include <linux/acpi.h>
  48
  49 #include <asm/uaccess.h>
  50 #include <asm/processor.h>
  51
  52 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
  53                      void __user *buffer, size_t *lenp, loff_t *ppos);
  54
  55 #ifdef CONFIG_X86
  56 #include <asm/nmi.h>
  57 #include <asm/stacktrace.h>
  58 #endif
  59
  60 #if defined(CONFIG_SYSCTL)
  61
  62 /* External variables not in a header file. */
  63 extern int C_A_D;
  64 extern int sysctl_overcommit_memory;
  65 extern int sysctl_overcommit_ratio;
  66 extern int sysctl_panic_on_oom;
  67 extern int max_threads;
  68 extern int core_uses_pid;
  69 extern int suid_dumpable;
  70 extern char core_pattern[];
  71 extern int pid_max;
  72 extern int min_free_kbytes;
  73 extern int printk_ratelimit_jiffies;
  74 extern int printk_ratelimit_burst;
  75 extern int pid_max_min, pid_max_max;
  76 extern int sysctl_drop_caches;
  77 extern int percpu_pagelist_fraction;
  78 extern int compat_log;
  79 extern int maps_protect;
  80 extern int sysctl_stat_interval;
  81
  82 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  83 static int maxolduid = 65535;
  84 static int minolduid;
  85 static int min_percpu_pagelist_fract = 8;
  86
  87 static int ngroups_max = NGROUPS_MAX;
  88
  89 #ifdef CONFIG_KMOD
  90 extern char modprobe_path[];
  91 #endif
  92 #ifdef CONFIG_CHR_DEV_SG
  93 extern int sg_big_buff;
  94 #endif
  95
  96 #ifdef __sparc__
  97 extern char reboot_command [];
  98 extern int stop_a_enabled;
  99 extern int scons_pwroff;
 100 #endif
 101
 102 #ifdef __hppa__
 103 extern int pwrsw_enabled;
 104 extern int unaligned_enabled;
 105 #endif
 106
 107 #ifdef CONFIG_S390
 108 #ifdef CONFIG_MATHEMU
 109 extern int sysctl_ieee_emulation_warnings;
 110 #endif
 111 extern int sysctl_userprocess_debug;
 112 extern int spin_retry;
 113 #endif
 114
 115 extern int sysctl_hz_timer;
 116
 117 #ifdef CONFIG_BSD_PROCESS_ACCT
 118 extern int acct_parm[];
 119 #endif
 120
 121 #ifdef CONFIG_IA64
 122 extern int no_unaligned_warning;
 123 #endif
 124
 125 #ifdef CONFIG_RT_MUTEXES
 126 extern int max_lock_depth;
 127 #endif
 128
 129 #ifdef CONFIG_SYSCTL_SYSCALL
 130 static int parse_table(int __user *, int, void __user *, size_t __user *,
 131                 void __user *, size_t, ctl_table *);
 132 #endif
 133
 134
 135 #ifdef CONFIG_PROC_SYSCTL
 136 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 137                   void __user *buffer, size_t *lenp, loff_t *ppos);
 138 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 139                                void __user *buffer, size_t *lenp, loff_t *ppos);
 140 #endif
 141
 142 static ctl_table root_table[];
 143 static struct ctl_table_header root_table_header =
 144         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 145
 146 static ctl_table kern_table[];
 147 static ctl_table vm_table[];
 148 static ctl_table fs_table[];
 149 static ctl_table debug_table[];
 150 static ctl_table dev_table[];
 151 extern ctl_table random_table[];
 152 #ifdef CONFIG_UNIX98_PTYS
 153 extern ctl_table pty_table[];
 154 #endif
 155 #ifdef CONFIG_INOTIFY_USER
 156 extern ctl_table inotify_table[];
 157 #endif
 158
 159 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 160 int sysctl_legacy_va_layout;
 161 #endif
 162
 163
 164 /* The default sysctl tables: */
 165
 166 static ctl_table root_table[] = {
 167         {
 168                 .ctl_name       = CTL_KERN,
 169                 .procname       = "kernel",
 170                 .mode           = 0555,
 171                 .child          = kern_table,
 172         },
 173         {
 174                 .ctl_name       = CTL_VM,
 175                 .procname       = "vm",
 176                 .mode           = 0555,
 177                 .child          = vm_table,
 178         },
 179 #ifdef CONFIG_NET
 180         {
 181                 .ctl_name       = CTL_NET,
 182                 .procname       = "net",
 183                 .mode           = 0555,
 184                 .child          = net_table,
 185         },
 186 #endif
 187         {
 188                 .ctl_name       = CTL_FS,
 189                 .procname       = "fs",
 190                 .mode           = 0555,
 191                 .child          = fs_table,
 192         },
 193         {
 194                 .ctl_name       = CTL_DEBUG,
 195                 .procname       = "debug",
 196                 .mode           = 0555,
 197                 .child          = debug_table,
 198         },
 199         {
 200                 .ctl_name       = CTL_DEV,
 201                 .procname       = "dev",
 202                 .mode           = 0555,
 203                 .child          = dev_table,
 204         },
 205
 206         { .ctl_name = 0 }
 207 };
 208
 209 #ifdef CONFIG_SCHED_DEBUG
 210 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 211 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 212 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 213 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 214 #endif
 215
 216 static ctl_table kern_table[] = {
 217 #ifdef CONFIG_SCHED_DEBUG
 218         {
 219                 .ctl_name       = CTL_UNNUMBERED,
 220                 .procname       = "sched_granularity_ns",
 221                 .data           = &sysctl_sched_granularity,
 222                 .maxlen         = sizeof(unsigned int),
 223                 .mode           = 0644,
 224                 .proc_handler   = &proc_dointvec_minmax,
 225                 .strategy       = &sysctl_intvec,
 226                 .extra1         = &min_sched_granularity_ns,
 227                 .extra2         = &max_sched_granularity_ns,
 228         },
 229         {
 230                 .ctl_name       = CTL_UNNUMBERED,
 231                 .procname       = "sched_wakeup_granularity_ns",
 232                 .data           = &sysctl_sched_wakeup_granularity,
 233                 .maxlen         = sizeof(unsigned int),
 234                 .mode           = 0644,
 235                 .proc_handler   = &proc_dointvec_minmax,
 236                 .strategy       = &sysctl_intvec,
 237                 .extra1         = &min_wakeup_granularity_ns,
 238                 .extra2         = &max_wakeup_granularity_ns,
 239         },
 240         {
 241                 .ctl_name       = CTL_UNNUMBERED,
 242                 .procname       = "sched_batch_wakeup_granularity_ns",
 243                 .data           = &sysctl_sched_batch_wakeup_granularity,
 244                 .maxlen         = sizeof(unsigned int),
 245                 .mode           = 0644,
 246                 .proc_handler   = &proc_dointvec_minmax,
 247                 .strategy       = &sysctl_intvec,
 248                 .extra1         = &min_wakeup_granularity_ns,
 249                 .extra2         = &max_wakeup_granularity_ns,
 250         },
 251         {
 252                 .ctl_name       = CTL_UNNUMBERED,
 253                 .procname       = "sched_stat_granularity_ns",
 254                 .data           = &sysctl_sched_stat_granularity,
 255                 .maxlen         = sizeof(unsigned int),
 256                 .mode           = 0644,
 257                 .proc_handler   = &proc_dointvec_minmax,
 258                 .strategy       = &sysctl_intvec,
 259                 .extra1         = &min_wakeup_granularity_ns,
 260                 .extra2         = &max_wakeup_granularity_ns,
 261         },
 262         {
 263                 .ctl_name       = CTL_UNNUMBERED,
 264                 .procname       = "sched_runtime_limit_ns",
 265                 .data           = &sysctl_sched_runtime_limit,
 266                 .maxlen         = sizeof(unsigned int),
 267                 .mode           = 0644,
 268                 .proc_handler   = &proc_dointvec_minmax,
 269                 .strategy       = &sysctl_intvec,
 270                 .extra1         = &min_sched_granularity_ns,
 271                 .extra2         = &max_sched_granularity_ns,
 272         },
 273         {
 274                 .ctl_name       = CTL_UNNUMBERED,
 275                 .procname       = "sched_child_runs_first",
 276                 .data           = &sysctl_sched_child_runs_first,
 277                 .maxlen         = sizeof(unsigned int),
 278                 .mode           = 0644,
 279                 .proc_handler   = &proc_dointvec,
 280         },
 281         {
 282                 .ctl_name       = CTL_UNNUMBERED,
 283                 .procname       = "sched_features",
 284                 .data           = &sysctl_sched_features,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289 #endif
 290         {
 291                 .ctl_name       = KERN_PANIC,
 292                 .procname       = "panic",
 293                 .data           = &panic_timeout,
 294                 .maxlen         = sizeof(int),
 295                 .mode           = 0644,
 296                 .proc_handler   = &proc_dointvec,
 297         },
 298         {
 299                 .ctl_name       = KERN_CORE_USES_PID,
 300                 .procname       = "core_uses_pid",
 301                 .data           = &core_uses_pid,
 302                 .maxlen         = sizeof(int),
 303                 .mode           = 0644,
 304                 .proc_handler   = &proc_dointvec,
 305         },
 306         {
 307                 .ctl_name       = KERN_CORE_PATTERN,
 308                 .procname       = "core_pattern",
 309                 .data           = core_pattern,
 310                 .maxlen         = CORENAME_MAX_SIZE,
 311                 .mode           = 0644,
 312                 .proc_handler   = &proc_dostring,
 313                 .strategy       = &sysctl_string,
 314         },
 315 #ifdef CONFIG_PROC_SYSCTL
 316         {
 317                 .ctl_name       = KERN_TAINTED,
 318                 .procname       = "tainted",
 319                 .data           = &tainted,
 320                 .maxlen         = sizeof(int),
 321                 .mode           = 0644,
 322                 .proc_handler   = &proc_dointvec_taint,
 323         },
 324 #endif
 325         {
 326                 .ctl_name       = KERN_CAP_BSET,
 327                 .procname       = "cap-bound",
 328                 .data           = &cap_bset,
 329                 .maxlen         = sizeof(kernel_cap_t),
 330                 .mode           = 0600,
 331                 .proc_handler   = &proc_dointvec_bset,
 332         },
 333 #ifdef CONFIG_BLK_DEV_INITRD
 334         {
 335                 .ctl_name       = KERN_REALROOTDEV,
 336                 .procname       = "real-root-dev",
 337                 .data           = &real_root_dev,
 338                 .maxlen         = sizeof(int),
 339                 .mode           = 0644,
 340                 .proc_handler   = &proc_dointvec,
 341         },
 342 #endif
 343 #ifdef __sparc__
 344         {
 345                 .ctl_name       = KERN_SPARC_REBOOT,
 346                 .procname       = "reboot-cmd",
 347                 .data           = reboot_command,
 348                 .maxlen         = 256,
 349                 .mode           = 0644,
 350                 .proc_handler   = &proc_dostring,
 351                 .strategy       = &sysctl_string,
 352         },
 353         {
 354                 .ctl_name       = KERN_SPARC_STOP_A,
 355                 .procname       = "stop-a",
 356                 .data           = &stop_a_enabled,
 357                 .maxlen         = sizeof (int),
 358                 .mode           = 0644,
 359                 .proc_handler   = &proc_dointvec,
 360         },
 361         {
 362                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 363                 .procname       = "scons-poweroff",
 364                 .data           = &scons_pwroff,
 365                 .maxlen         = sizeof (int),
 366                 .mode           = 0644,
 367                 .proc_handler   = &proc_dointvec,
 368         },
 369 #endif
 370 #ifdef __hppa__
 371         {
 372                 .ctl_name       = KERN_HPPA_PWRSW,
 373                 .procname       = "soft-power",
 374                 .data           = &pwrsw_enabled,
 375                 .maxlen         = sizeof (int),
 376                 .mode           = 0644,
 377                 .proc_handler   = &proc_dointvec,
 378         },
 379         {
 380                 .ctl_name       = KERN_HPPA_UNALIGNED,
 381                 .procname       = "unaligned-trap",
 382                 .data           = &unaligned_enabled,
 383                 .maxlen         = sizeof (int),
 384                 .mode           = 0644,
 385                 .proc_handler   = &proc_dointvec,
 386         },
 387 #endif
 388         {
 389                 .ctl_name       = KERN_CTLALTDEL,
 390                 .procname       = "ctrl-alt-del",
 391                 .data           = &C_A_D,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = &proc_dointvec,
 395         },
 396         {
 397                 .ctl_name       = KERN_PRINTK,
 398                 .procname       = "printk",
 399                 .data           = &console_loglevel,
 400                 .maxlen         = 4*sizeof(int),
 401                 .mode           = 0644,
 402                 .proc_handler   = &proc_dointvec,
 403         },
 404 #ifdef CONFIG_KMOD
 405         {
 406                 .ctl_name       = KERN_MODPROBE,
 407                 .procname       = "modprobe",
 408                 .data           = &modprobe_path,
 409                 .maxlen         = KMOD_PATH_LEN,
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dostring,
 412                 .strategy       = &sysctl_string,
 413         },
 414 #endif
 415 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 416         {
 417                 .ctl_name       = KERN_HOTPLUG,
 418                 .procname       = "hotplug",
 419                 .data           = &uevent_helper,
 420                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 421                 .mode           = 0644,
 422                 .proc_handler   = &proc_dostring,
 423                 .strategy       = &sysctl_string,
 424         },
 425 #endif
 426 #ifdef CONFIG_CHR_DEV_SG
 427         {
 428                 .ctl_name       = KERN_SG_BIG_BUFF,
 429                 .procname       = "sg-big-buff",
 430                 .data           = &sg_big_buff,
 431                 .maxlen         = sizeof (int),
 432                 .mode           = 0444,
 433                 .proc_handler   = &proc_dointvec,
 434         },
 435 #endif
 436 #ifdef CONFIG_BSD_PROCESS_ACCT
 437         {
 438                 .ctl_name       = KERN_ACCT,
 439                 .procname       = "acct",
 440                 .data           = &acct_parm,
 441                 .maxlen         = 3*sizeof(int),
 442                 .mode           = 0644,
 443                 .proc_handler   = &proc_dointvec,
 444         },
 445 #endif
 446 #ifdef CONFIG_MAGIC_SYSRQ
 447         {
 448                 .ctl_name       = KERN_SYSRQ,
 449                 .procname       = "sysrq",
 450                 .data           = &__sysrq_enabled,
 451                 .maxlen         = sizeof (int),
 452                 .mode           = 0644,
 453                 .proc_handler   = &proc_dointvec,
 454         },
 455 #endif
 456 #ifdef CONFIG_PROC_SYSCTL
 457         {
 458                 .ctl_name       = KERN_CADPID,
 459                 .procname       = "cad_pid",
 460                 .data           = NULL,
 461                 .maxlen         = sizeof (int),
 462                 .mode           = 0600,
 463                 .proc_handler   = &proc_do_cad_pid,
 464         },
 465 #endif
 466         {
 467                 .ctl_name       = KERN_MAX_THREADS,
 468                 .procname       = "threads-max",
 469                 .data           = &max_threads,
 470                 .maxlen         = sizeof(int),
 471                 .mode           = 0644,
 472                 .proc_handler   = &proc_dointvec,
 473         },
 474         {
 475                 .ctl_name       = KERN_RANDOM,
 476                 .procname       = "random",
 477                 .mode           = 0555,
 478                 .child          = random_table,
 479         },
 480 #ifdef CONFIG_UNIX98_PTYS
 481         {
 482                 .ctl_name       = KERN_PTY,
 483                 .procname       = "pty",
 484                 .mode           = 0555,
 485                 .child          = pty_table,
 486         },
 487 #endif
 488         {
 489                 .ctl_name       = KERN_OVERFLOWUID,
 490                 .procname       = "overflowuid",
 491                 .data           = &overflowuid,
 492                 .maxlen         = sizeof(int),
 493                 .mode           = 0644,
 494                 .proc_handler   = &proc_dointvec_minmax,
 495                 .strategy       = &sysctl_intvec,
 496                 .extra1         = &minolduid,
 497                 .extra2         = &maxolduid,
 498         },
 499         {
 500                 .ctl_name       = KERN_OVERFLOWGID,
 501                 .procname       = "overflowgid",
 502                 .data           = &overflowgid,
 503                 .maxlen         = sizeof(int),
 504                 .mode           = 0644,
 505                 .proc_handler   = &proc_dointvec_minmax,
 506                 .strategy       = &sysctl_intvec,
 507                 .extra1         = &minolduid,
 508                 .extra2         = &maxolduid,
 509         },
 510 #ifdef CONFIG_S390
 511 #ifdef CONFIG_MATHEMU
 512         {
 513                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 514                 .procname       = "ieee_emulation_warnings",
 515                 .data           = &sysctl_ieee_emulation_warnings,
 516                 .maxlen         = sizeof(int),
 517                 .mode           = 0644,
 518                 .proc_handler   = &proc_dointvec,
 519         },
 520 #endif
 521 #ifdef CONFIG_NO_IDLE_HZ
 522         {
 523                 .ctl_name       = KERN_HZ_TIMER,
 524                 .procname       = "hz_timer",
 525                 .data           = &sysctl_hz_timer,
 526                 .maxlen         = sizeof(int),
 527                 .mode           = 0644,
 528                 .proc_handler   = &proc_dointvec,
 529         },
 530 #endif
 531         {
 532                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 533                 .procname       = "userprocess_debug",
 534                 .data           = &sysctl_userprocess_debug,
 535                 .maxlen         = sizeof(int),
 536                 .mode           = 0644,
 537                 .proc_handler   = &proc_dointvec,
 538         },
 539 #endif
 540         {
 541                 .ctl_name       = KERN_PIDMAX,
 542                 .procname       = "pid_max",
 543                 .data           = &pid_max,
 544                 .maxlen         = sizeof (int),
 545                 .mode           = 0644,
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .strategy       = sysctl_intvec,
 548                 .extra1         = &pid_max_min,
 549                 .extra2         = &pid_max_max,
 550         },
 551         {
 552                 .ctl_name       = KERN_PANIC_ON_OOPS,
 553                 .procname       = "panic_on_oops",
 554                 .data           = &panic_on_oops,
 555                 .maxlen         = sizeof(int),
 556                 .mode           = 0644,
 557                 .proc_handler   = &proc_dointvec,
 558         },
 559         {
 560                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 561                 .procname       = "printk_ratelimit",
 562                 .data           = &printk_ratelimit_jiffies,
 563                 .maxlen         = sizeof(int),
 564                 .mode           = 0644,
 565                 .proc_handler   = &proc_dointvec_jiffies,
 566                 .strategy       = &sysctl_jiffies,
 567         },
 568         {
 569                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 570                 .procname       = "printk_ratelimit_burst",
 571                 .data           = &printk_ratelimit_burst,
 572                 .maxlen         = sizeof(int),
 573                 .mode           = 0644,
 574                 .proc_handler   = &proc_dointvec,
 575         },
 576         {
 577                 .ctl_name       = KERN_NGROUPS_MAX,
 578                 .procname       = "ngroups_max",
 579                 .data           = &ngroups_max,
 580                 .maxlen         = sizeof (int),
 581                 .mode           = 0444,
 582                 .proc_handler   = &proc_dointvec,
 583         },
 584 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 585         {
 586                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 587                 .procname       = "unknown_nmi_panic",
 588                 .data           = &unknown_nmi_panic,
 589                 .maxlen         = sizeof (int),
 590                 .mode           = 0644,
 591                 .proc_handler   = &proc_dointvec,
 592         },
 593         {
 594                 .ctl_name       = KERN_NMI_WATCHDOG,
 595                 .procname       = "nmi_watchdog",
 596                 .data           = &nmi_watchdog_enabled,
 597                 .maxlen         = sizeof (int),
 598                 .mode           = 0644,
 599                 .proc_handler   = &proc_nmi_enabled,
 600         },
 601 #endif
 602 #if defined(CONFIG_X86)
 603         {
 604                 .ctl_name       = KERN_PANIC_ON_NMI,
 605                 .procname       = "panic_on_unrecovered_nmi",
 606                 .data           = &panic_on_unrecovered_nmi,
 607                 .maxlen         = sizeof(int),
 608                 .mode           = 0644,
 609                 .proc_handler   = &proc_dointvec,
 610         },
 611         {
 612                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 613                 .procname       = "bootloader_type",
 614                 .data           = &bootloader_type,
 615                 .maxlen         = sizeof (int),
 616                 .mode           = 0444,
 617                 .proc_handler   = &proc_dointvec,
 618         },
 619         {
 620                 .ctl_name       = CTL_UNNUMBERED,
 621                 .procname       = "kstack_depth_to_print",
 622                 .data           = &kstack_depth_to_print,
 623                 .maxlen         = sizeof(int),
 624                 .mode           = 0644,
 625                 .proc_handler   = &proc_dointvec,
 626         },
 627 #endif
 628 #if defined(CONFIG_MMU)
 629         {
 630                 .ctl_name       = KERN_RANDOMIZE,
 631                 .procname       = "randomize_va_space",
 632                 .data           = &randomize_va_space,
 633                 .maxlen         = sizeof(int),
 634                 .mode           = 0644,
 635                 .proc_handler   = &proc_dointvec,
 636         },
 637 #endif
 638 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 639         {
 640                 .ctl_name       = KERN_SPIN_RETRY,
 641                 .procname       = "spin_retry",
 642                 .data           = &spin_retry,
 643                 .maxlen         = sizeof (int),
 644                 .mode           = 0644,
 645                 .proc_handler   = &proc_dointvec,
 646         },
 647 #endif
 648 #ifdef CONFIG_ACPI_SLEEP
 649         {
 650                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 651                 .procname       = "acpi_video_flags",
 652                 .data           = &acpi_video_flags,
 653                 .maxlen         = sizeof (unsigned long),
 654                 .mode           = 0644,
 655                 .proc_handler   = &proc_doulongvec_minmax,
 656         },
 657 #endif
 658 #ifdef CONFIG_IA64
 659         {
 660                 .ctl_name       = KERN_IA64_UNALIGNED,
 661                 .procname       = "ignore-unaligned-usertrap",
 662                 .data           = &no_unaligned_warning,
 663                 .maxlen         = sizeof (int),
 664                 .mode           = 0644,
 665                 .proc_handler   = &proc_dointvec,
 666         },
 667 #endif
 668 #ifdef CONFIG_COMPAT
 669         {
 670                 .ctl_name       = KERN_COMPAT_LOG,
 671                 .procname       = "compat-log",
 672                 .data           = &compat_log,
 673                 .maxlen         = sizeof (int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678 #ifdef CONFIG_RT_MUTEXES
 679         {
 680                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 681                 .procname       = "max_lock_depth",
 682                 .data           = &max_lock_depth,
 683                 .maxlen         = sizeof(int),
 684                 .mode           = 0644,
 685                 .proc_handler   = &proc_dointvec,
 686         },
 687 #endif
 688 #ifdef CONFIG_PROC_FS
 689         {
 690                 .ctl_name       = CTL_UNNUMBERED,
 691                 .procname       = "maps_protect",
 692                 .data           = &maps_protect,
 693                 .maxlen         = sizeof(int),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_dointvec,
 696         },
 697 #endif
 698
 699         { .ctl_name = 0 }
 700 };
 701
 702 /* Constants for minimum and maximum testing in vm_table.
 703    We use these as one-element integer vectors. */
 704 static int zero;
 705 static int one_hundred = 100;
 706
 707
 708 static ctl_table vm_table[] = {
 709         {
 710                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 711                 .procname       = "overcommit_memory",
 712                 .data           = &sysctl_overcommit_memory,
 713                 .maxlen         = sizeof(sysctl_overcommit_memory),
 714                 .mode           = 0644,
 715                 .proc_handler   = &proc_dointvec,
 716         },
 717         {
 718                 .ctl_name       = VM_PANIC_ON_OOM,
 719                 .procname       = "panic_on_oom",
 720                 .data           = &sysctl_panic_on_oom,
 721                 .maxlen         = sizeof(sysctl_panic_on_oom),
 722                 .mode           = 0644,
 723                 .proc_handler   = &proc_dointvec,
 724         },
 725         {
 726                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 727                 .procname       = "overcommit_ratio",
 728                 .data           = &sysctl_overcommit_ratio,
 729                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 730                 .mode           = 0644,
 731                 .proc_handler   = &proc_dointvec,
 732         },
 733         {
 734                 .ctl_name       = VM_PAGE_CLUSTER,
 735                 .procname       = "page-cluster",
 736                 .data           = &page_cluster,
 737                 .maxlen         = sizeof(int),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec,
 740         },
 741         {
 742                 .ctl_name       = VM_DIRTY_BACKGROUND,
 743                 .procname       = "dirty_background_ratio",
 744                 .data           = &dirty_background_ratio,
 745                 .maxlen         = sizeof(dirty_background_ratio),
 746                 .mode           = 0644,
 747                 .proc_handler   = &proc_dointvec_minmax,
 748                 .strategy       = &sysctl_intvec,
 749                 .extra1         = &zero,
 750                 .extra2         = &one_hundred,
 751         },
 752         {
 753                 .ctl_name       = VM_DIRTY_RATIO,
 754                 .procname       = "dirty_ratio",
 755                 .data           = &vm_dirty_ratio,
 756                 .maxlen         = sizeof(vm_dirty_ratio),
 757                 .mode           = 0644,
 758                 .proc_handler   = &proc_dointvec_minmax,
 759                 .strategy       = &sysctl_intvec,
 760                 .extra1         = &zero,
 761                 .extra2         = &one_hundred,
 762         },
 763         {
 764                 .ctl_name       = VM_DIRTY_WB_CS,
 765                 .procname       = "dirty_writeback_centisecs",
 766                 .data           = &dirty_writeback_interval,
 767                 .maxlen         = sizeof(dirty_writeback_interval),
 768                 .mode           = 0644,
 769                 .proc_handler   = &dirty_writeback_centisecs_handler,
 770         },
 771         {
 772                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 773                 .procname       = "dirty_expire_centisecs",
 774                 .data           = &dirty_expire_interval,
 775                 .maxlen         = sizeof(dirty_expire_interval),
 776                 .mode           = 0644,
 777                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 778         },
 779         {
 780                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 781                 .procname       = "nr_pdflush_threads",
 782                 .data           = &nr_pdflush_threads,
 783                 .maxlen         = sizeof nr_pdflush_threads,
 784                 .mode           = 0444 /* read-only*/,
 785                 .proc_handler   = &proc_dointvec,
 786         },
 787         {
 788                 .ctl_name       = VM_SWAPPINESS,
 789                 .procname       = "swappiness",
 790                 .data           = &vm_swappiness,
 791                 .maxlen         = sizeof(vm_swappiness),
 792                 .mode           = 0644,
 793                 .proc_handler   = &proc_dointvec_minmax,
 794                 .strategy       = &sysctl_intvec,
 795                 .extra1         = &zero,
 796                 .extra2         = &one_hundred,
 797         },
 798 #ifdef CONFIG_HUGETLB_PAGE
 799          {
 800                 .ctl_name       = VM_HUGETLB_PAGES,
 801                 .procname       = "nr_hugepages",
 802                 .data           = &max_huge_pages,
 803                 .maxlen         = sizeof(unsigned long),
 804                 .mode           = 0644,
 805                 .proc_handler   = &hugetlb_sysctl_handler,
 806                 .extra1         = (void *)&hugetlb_zero,
 807                 .extra2         = (void *)&hugetlb_infinity,
 808          },
 809          {
 810                 .ctl_name       = VM_HUGETLB_GROUP,
 811                 .procname       = "hugetlb_shm_group",
 812                 .data           = &sysctl_hugetlb_shm_group,
 813                 .maxlen         = sizeof(gid_t),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dointvec,
 816          },
 817 #endif
 818         {
 819                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 820                 .procname       = "lowmem_reserve_ratio",
 821                 .data           = &sysctl_lowmem_reserve_ratio,
 822                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 823                 .mode           = 0644,
 824                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 825                 .strategy       = &sysctl_intvec,
 826         },
 827         {
 828                 .ctl_name       = VM_DROP_PAGECACHE,
 829                 .procname       = "drop_caches",
 830                 .data           = &sysctl_drop_caches,
 831                 .maxlen         = sizeof(int),
 832                 .mode           = 0644,
 833                 .proc_handler   = drop_caches_sysctl_handler,
 834                 .strategy       = &sysctl_intvec,
 835         },
 836         {
 837                 .ctl_name       = VM_MIN_FREE_KBYTES,
 838                 .procname       = "min_free_kbytes",
 839                 .data           = &min_free_kbytes,
 840                 .maxlen         = sizeof(min_free_kbytes),
 841                 .mode           = 0644,
 842                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 843                 .strategy       = &sysctl_intvec,
 844                 .extra1         = &zero,
 845         },
 846         {
 847                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 848                 .procname       = "percpu_pagelist_fraction",
 849                 .data           = &percpu_pagelist_fraction,
 850                 .maxlen         = sizeof(percpu_pagelist_fraction),
 851                 .mode           = 0644,
 852                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 853                 .strategy       = &sysctl_intvec,
 854                 .extra1         = &min_percpu_pagelist_fract,
 855         },
 856 #ifdef CONFIG_MMU
 857         {
 858                 .ctl_name       = VM_MAX_MAP_COUNT,
 859                 .procname       = "max_map_count",
 860                 .data           = &sysctl_max_map_count,
 861                 .maxlen         = sizeof(sysctl_max_map_count),
 862                 .mode           = 0644,
 863                 .proc_handler   = &proc_dointvec
 864         },
 865 #endif
 866         {
 867                 .ctl_name       = VM_LAPTOP_MODE,
 868                 .procname       = "laptop_mode",
 869                 .data           = &laptop_mode,
 870                 .maxlen         = sizeof(laptop_mode),
 871                 .mode           = 0644,
 872                 .proc_handler   = &proc_dointvec_jiffies,
 873                 .strategy       = &sysctl_jiffies,
 874         },
 875         {
 876                 .ctl_name       = VM_BLOCK_DUMP,
 877                 .procname       = "block_dump",
 878                 .data           = &block_dump,
 879                 .maxlen         = sizeof(block_dump),
 880                 .mode           = 0644,
 881                 .proc_handler   = &proc_dointvec,
 882                 .strategy       = &sysctl_intvec,
 883                 .extra1         = &zero,
 884         },
 885         {
 886                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 887                 .procname       = "vfs_cache_pressure",
 888                 .data           = &sysctl_vfs_cache_pressure,
 889                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 890                 .mode           = 0644,
 891                 .proc_handler   = &proc_dointvec,
 892                 .strategy       = &sysctl_intvec,
 893                 .extra1         = &zero,
 894         },
 895 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 896         {
 897                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 898                 .procname       = "legacy_va_layout",
 899                 .data           = &sysctl_legacy_va_layout,
 900                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 901                 .mode           = 0644,
 902                 .proc_handler   = &proc_dointvec,
 903                 .strategy       = &sysctl_intvec,
 904                 .extra1         = &zero,
 905         },
 906 #endif
 907 #ifdef CONFIG_NUMA
 908         {
 909                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 910                 .procname       = "zone_reclaim_mode",
 911                 .data           = &zone_reclaim_mode,
 912                 .maxlen         = sizeof(zone_reclaim_mode),
 913                 .mode           = 0644,
 914                 .proc_handler   = &proc_dointvec,
 915                 .strategy       = &sysctl_intvec,
 916                 .extra1         = &zero,
 917         },
 918         {
 919                 .ctl_name       = VM_MIN_UNMAPPED,
 920                 .procname       = "min_unmapped_ratio",
 921                 .data           = &sysctl_min_unmapped_ratio,
 922                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 923                 .mode           = 0644,
 924                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 925                 .strategy       = &sysctl_intvec,
 926                 .extra1         = &zero,
 927                 .extra2         = &one_hundred,
 928         },
 929         {
 930                 .ctl_name       = VM_MIN_SLAB,
 931                 .procname       = "min_slab_ratio",
 932                 .data           = &sysctl_min_slab_ratio,
 933                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 934                 .mode           = 0644,
 935                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 936                 .strategy       = &sysctl_intvec,
 937                 .extra1         = &zero,
 938                 .extra2         = &one_hundred,
 939         },
 940 #endif
 941 #ifdef CONFIG_SMP
 942         {
 943                 .ctl_name       = CTL_UNNUMBERED,
 944                 .procname       = "stat_interval",
 945                 .data           = &sysctl_stat_interval,
 946                 .maxlen         = sizeof(sysctl_stat_interval),
 947                 .mode           = 0644,
 948                 .proc_handler   = &proc_dointvec_jiffies,
 949                 .strategy       = &sysctl_jiffies,
 950         },
 951 #endif
 952 #ifdef CONFIG_SECURITY
 953         {
 954                 .ctl_name       = CTL_UNNUMBERED,
 955                 .procname       = "mmap_min_addr",
 956                 .data           = &mmap_min_addr,
 957                 .maxlen         = sizeof(unsigned long),
 958                 .mode           = 0644,
 959                 .proc_handler   = &proc_doulongvec_minmax,
 960         },
 961 #ifdef CONFIG_NUMA
 962         {
 963                 .ctl_name       = CTL_UNNUMBERED,
 964                 .procname       = "numa_zonelist_order",
 965                 .data           = &numa_zonelist_order,
 966                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
 967                 .mode           = 0644,
 968                 .proc_handler   = &numa_zonelist_order_handler,
 969                 .strategy       = &sysctl_string,
 970         },
 971 #endif
 972 #endif
 973 #if defined(CONFIG_X86_32) || \
 974    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
 975         {
 976                 .ctl_name       = VM_VDSO_ENABLED,
 977                 .procname       = "vdso_enabled",
 978                 .data           = &vdso_enabled,
 979                 .maxlen         = sizeof(vdso_enabled),
 980                 .mode           = 0644,
 981                 .proc_handler   = &proc_dointvec,
 982                 .strategy       = &sysctl_intvec,
 983                 .extra1         = &zero,
 984         },
 985 #endif
 986         { .ctl_name = 0 }
 987 };
 988
 989 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
 990 static ctl_table binfmt_misc_table[] = {
 991         { .ctl_name = 0 }
 992 };
 993 #endif
 994
 995 static ctl_table fs_table[] = {
 996         {
 997                 .ctl_name       = FS_NRINODE,
 998                 .procname       = "inode-nr",
 999                 .data           = &inodes_stat,
1000                 .maxlen         = 2*sizeof(int),
1001                 .mode           = 0444,
1002                 .proc_handler   = &proc_dointvec,
1003         },
1004         {
1005                 .ctl_name       = FS_STATINODE,
1006                 .procname       = "inode-state",
1007                 .data           = &inodes_stat,
1008                 .maxlen         = 7*sizeof(int),
1009                 .mode           = 0444,
1010                 .proc_handler   = &proc_dointvec,
1011         },
1012         {
1013                 .ctl_name       = FS_NRFILE,
1014                 .procname       = "file-nr",
1015                 .data           = &files_stat,
1016                 .maxlen         = 3*sizeof(int),
1017                 .mode           = 0444,
1018                 .proc_handler   = &proc_nr_files,
1019         },
1020         {
1021                 .ctl_name       = FS_MAXFILE,
1022                 .procname       = "file-max",
1023                 .data           = &files_stat.max_files,
1024                 .maxlen         = sizeof(int),
1025                 .mode           = 0644,
1026                 .proc_handler   = &proc_dointvec,
1027         },
1028         {
1029                 .ctl_name       = FS_DENTRY,
1030                 .procname       = "dentry-state",
1031                 .data           = &dentry_stat,
1032                 .maxlen         = 6*sizeof(int),
1033                 .mode           = 0444,
1034                 .proc_handler   = &proc_dointvec,
1035         },
1036         {
1037                 .ctl_name       = FS_OVERFLOWUID,
1038                 .procname       = "overflowuid",
1039                 .data           = &fs_overflowuid,
1040                 .maxlen         = sizeof(int),
1041                 .mode           = 0644,
1042                 .proc_handler   = &proc_dointvec_minmax,
1043                 .strategy       = &sysctl_intvec,
1044                 .extra1         = &minolduid,
1045                 .extra2         = &maxolduid,
1046         },
1047         {
1048                 .ctl_name       = FS_OVERFLOWGID,
1049                 .procname       = "overflowgid",
1050                 .data           = &fs_overflowgid,
1051                 .maxlen         = sizeof(int),
1052                 .mode           = 0644,
1053                 .proc_handler   = &proc_dointvec_minmax,
1054                 .strategy       = &sysctl_intvec,
1055                 .extra1         = &minolduid,
1056                 .extra2         = &maxolduid,
1057         },
1058         {
1059                 .ctl_name       = FS_LEASES,
1060                 .procname       = "leases-enable",
1061                 .data           = &leases_enable,
1062                 .maxlen         = sizeof(int),
1063                 .mode           = 0644,
1064                 .proc_handler   = &proc_dointvec,
1065         },
1066 #ifdef CONFIG_DNOTIFY
1067         {
1068                 .ctl_name       = FS_DIR_NOTIFY,
1069                 .procname       = "dir-notify-enable",
1070                 .data           = &dir_notify_enable,
1071                 .maxlen         = sizeof(int),
1072                 .mode           = 0644,
1073                 .proc_handler   = &proc_dointvec,
1074         },
1075 #endif
1076 #ifdef CONFIG_MMU
1077         {
1078                 .ctl_name       = FS_LEASE_TIME,
1079                 .procname       = "lease-break-time",
1080                 .data           = &lease_break_time,
1081                 .maxlen         = sizeof(int),
1082                 .mode           = 0644,
1083                 .proc_handler   = &proc_dointvec,
1084         },
1085         {
1086                 .ctl_name       = FS_AIO_NR,
1087                 .procname       = "aio-nr",
1088                 .data           = &aio_nr,
1089                 .maxlen         = sizeof(aio_nr),
1090                 .mode           = 0444,
1091                 .proc_handler   = &proc_doulongvec_minmax,
1092         },
1093         {
1094                 .ctl_name       = FS_AIO_MAX_NR,
1095                 .procname       = "aio-max-nr",
1096                 .data           = &aio_max_nr,
1097                 .maxlen         = sizeof(aio_max_nr),
1098                 .mode           = 0644,
1099                 .proc_handler   = &proc_doulongvec_minmax,
1100         },
1101 #ifdef CONFIG_INOTIFY_USER
1102         {
1103                 .ctl_name       = FS_INOTIFY,
1104                 .procname       = "inotify",
1105                 .mode           = 0555,
1106                 .child          = inotify_table,
1107         },
1108 #endif
1109 #endif
1110         {
1111                 .ctl_name       = KERN_SETUID_DUMPABLE,
1112                 .procname       = "suid_dumpable",
1113                 .data           = &suid_dumpable,
1114                 .maxlen         = sizeof(int),
1115                 .mode           = 0644,
1116                 .proc_handler   = &proc_dointvec,
1117         },
1118 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1119         {
1120                 .ctl_name       = CTL_UNNUMBERED,
1121                 .procname       = "binfmt_misc",
1122                 .mode           = 0555,
1123                 .child          = binfmt_misc_table,
1124         },
1125 #endif
1126         { .ctl_name = 0 }
1127 };
1128
1129 static ctl_table debug_table[] = {
1130         { .ctl_name = 0 }
1131 };
1132
1133 static ctl_table dev_table[] = {
1134         { .ctl_name = 0 }
1135 };
1136
1137 static DEFINE_SPINLOCK(sysctl_lock);
1138
1139 /* called under sysctl_lock */
1140 static int use_table(struct ctl_table_header *p)
1141 {
1142         if (unlikely(p->unregistering))
1143                 return 0;
1144         p->used++;
1145         return 1;
1146 }
1147
1148 /* called under sysctl_lock */
1149 static void unuse_table(struct ctl_table_header *p)
1150 {
1151         if (!--p->used)
1152                 if (unlikely(p->unregistering))
1153                         complete(p->unregistering);
1154 }
1155
1156 /* called under sysctl_lock, will reacquire if has to wait */
1157 static void start_unregistering(struct ctl_table_header *p)
1158 {
1159         /*
1160          * if p->used is 0, nobody will ever touch that entry again;
1161          * we'll eliminate all paths to it before dropping sysctl_lock
1162          */
1163         if (unlikely(p->used)) {
1164                 struct completion wait;
1165                 init_completion(&wait);
1166                 p->unregistering = &wait;
1167                 spin_unlock(&sysctl_lock);
1168                 wait_for_completion(&wait);
1169                 spin_lock(&sysctl_lock);
1170         }
1171         /*
1172          * do not remove from the list until nobody holds it; walking the
1173          * list in do_sysctl() relies on that.
1174          */
1175         list_del_init(&p->ctl_entry);
1176 }
1177
1178 void sysctl_head_finish(struct ctl_table_header *head)
1179 {
1180         if (!head)
1181                 return;
1182         spin_lock(&sysctl_lock);
1183         unuse_table(head);
1184         spin_unlock(&sysctl_lock);
1185 }
1186
1187 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1188 {
1189         struct ctl_table_header *head;
1190         struct list_head *tmp;
1191         spin_lock(&sysctl_lock);
1192         if (prev) {
1193                 tmp = &prev->ctl_entry;
1194                 unuse_table(prev);
1195                 goto next;
1196         }
1197         tmp = &root_table_header.ctl_entry;
1198         for (;;) {
1199                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1200
1201                 if (!use_table(head))
1202                         goto next;
1203                 spin_unlock(&sysctl_lock);
1204                 return head;
1205         next:
1206                 tmp = tmp->next;
1207                 if (tmp == &root_table_header.ctl_entry)
1208                         break;
1209         }
1210         spin_unlock(&sysctl_lock);
1211         return NULL;
1212 }
1213
1214 #ifdef CONFIG_SYSCTL_SYSCALL
1215 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1216                void __user *newval, size_t newlen)
1217 {
1218         struct ctl_table_header *head;
1219         int error = -ENOTDIR;
1220
1221         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1222                 return -ENOTDIR;
1223         if (oldval) {
1224                 int old_len;
1225                 if (!oldlenp || get_user(old_len, oldlenp))
1226                         return -EFAULT;
1227         }
1228
1229         for (head = sysctl_head_next(NULL); head;
1230                         head = sysctl_head_next(head)) {
1231                 error = parse_table(name, nlen, oldval, oldlenp,
1232                                         newval, newlen, head->ctl_table);
1233                 if (error != -ENOTDIR) {
1234                         sysctl_head_finish(head);
1235                         break;
1236                 }
1237         }
1238         return error;
1239 }
1240
1241 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1242 {
1243         struct __sysctl_args tmp;
1244         int error;
1245
1246         if (copy_from_user(&tmp, args, sizeof(tmp)))
1247                 return -EFAULT;
1248
1249         lock_kernel();
1250         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1251                           tmp.newval, tmp.newlen);
1252         unlock_kernel();
1253         return error;
1254 }
1255 #endif /* CONFIG_SYSCTL_SYSCALL */
1256
1257 /*
1258  * sysctl_perm does NOT grant the superuser all rights automatically, because
1259  * some sysctl variables are readonly even to root.
1260  */
1261
1262 static int test_perm(int mode, int op)
1263 {
1264         if (!current->euid)
1265                 mode >>= 6;
1266         else if (in_egroup_p(0))
1267                 mode >>= 3;
1268         if ((mode & op & 0007) == op)
1269                 return 0;
1270         return -EACCES;
1271 }
1272
1273 int sysctl_perm(ctl_table *table, int op)
1274 {
1275         int error;
1276         error = security_sysctl(table, op);
1277         if (error)
1278                 return error;
1279         return test_perm(table->mode, op);
1280 }
1281
1282 #ifdef CONFIG_SYSCTL_SYSCALL
1283 static int parse_table(int __user *name, int nlen,
1284                        void __user *oldval, size_t __user *oldlenp,
1285                        void __user *newval, size_t newlen,
1286                        ctl_table *table)
1287 {
1288         int n;
1289 repeat:
1290         if (!nlen)
1291                 return -ENOTDIR;
1292         if (get_user(n, name))
1293                 return -EFAULT;
1294         for ( ; table->ctl_name || table->procname; table++) {
1295                 if (!table->ctl_name)
1296                         continue;
1297                 if (n == table->ctl_name) {
1298                         int error;
1299                         if (table->child) {
1300                                 if (sysctl_perm(table, 001))
1301                                         return -EPERM;
1302                                 name++;
1303                                 nlen--;
1304                                 table = table->child;
1305                                 goto repeat;
1306                         }
1307                         error = do_sysctl_strategy(table, name, nlen,
1308                                                    oldval, oldlenp,
1309                                                    newval, newlen);
1310                         return error;
1311                 }
1312         }
1313         return -ENOTDIR;
1314 }
1315
1316 /* Perform the actual read/write of a sysctl table entry. */
1317 int do_sysctl_strategy (ctl_table *table,
1318                         int __user *name, int nlen,
1319                         void __user *oldval, size_t __user *oldlenp,
1320                         void __user *newval, size_t newlen)
1321 {
1322         int op = 0, rc;
1323         size_t len;
1324
1325         if (oldval)
1326                 op |= 004;
1327         if (newval)
1328                 op |= 002;
1329         if (sysctl_perm(table, op))
1330                 return -EPERM;
1331
1332         if (table->strategy) {
1333                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1334                                      newval, newlen);
1335                 if (rc < 0)
1336                         return rc;
1337                 if (rc > 0)
1338                         return 0;
1339         }
1340
1341         /* If there is no strategy routine, or if the strategy returns
1342          * zero, proceed with automatic r/w */
1343         if (table->data && table->maxlen) {
1344                 if (oldval && oldlenp) {
1345                         if (get_user(len, oldlenp))
1346                                 return -EFAULT;
1347                         if (len) {
1348                                 if (len > table->maxlen)
1349                                         len = table->maxlen;
1350                                 if(copy_to_user(oldval, table->data, len))
1351                                         return -EFAULT;
1352                                 if(put_user(len, oldlenp))
1353                                         return -EFAULT;
1354                         }
1355                 }
1356                 if (newval && newlen) {
1357                         len = newlen;
1358                         if (len > table->maxlen)
1359                                 len = table->maxlen;
1360                         if(copy_from_user(table->data, newval, len))
1361                                 return -EFAULT;
1362                 }
1363         }
1364         return 0;
1365 }
1366 #endif /* CONFIG_SYSCTL_SYSCALL */
1367
1368 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1369 {
1370         for (; table->ctl_name || table->procname; table++) {
1371                 table->parent = parent;
1372                 if (table->child)
1373                         sysctl_set_parent(table, table->child);
1374         }
1375 }
1376
1377 static __init int sysctl_init(void)
1378 {
1379         sysctl_set_parent(NULL, root_table);
1380         return 0;
1381 }
1382
1383 core_initcall(sysctl_init);
1384
1385 /**
1386  * register_sysctl_table - register a sysctl hierarchy
1387  * @table: the top-level table structure
1388  *
1389  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1390  * array. An entry with a ctl_name of 0 terminates the table.
1391  *
1392  * The members of the &ctl_table structure are used as follows:
1393  *
1394  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1395  *            must be unique within that level of sysctl
1396  *
1397  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1398  *            enter a sysctl file
1399  *
1400  * data - a pointer to data for use by proc_handler
1401  *
1402  * maxlen - the maximum size in bytes of the data
1403  *
1404  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1405  *
1406  * child - a pointer to the child sysctl table if this entry is a directory, or
1407  *         %NULL.
1408  *
1409  * proc_handler - the text handler routine (described below)
1410  *
1411  * strategy - the strategy routine (described below)
1412  *
1413  * de - for internal use by the sysctl routines
1414  *
1415  * extra1, extra2 - extra pointers usable by the proc handler routines
1416  *
1417  * Leaf nodes in the sysctl tree will be represented by a single file
1418  * under /proc; non-leaf nodes will be represented by directories.
1419  *
1420  * sysctl(2) can automatically manage read and write requests through
1421  * the sysctl table.  The data and maxlen fields of the ctl_table
1422  * struct enable minimal validation of the values being written to be
1423  * performed, and the mode field allows minimal authentication.
1424  *
1425  * More sophisticated management can be enabled by the provision of a
1426  * strategy routine with the table entry.  This will be called before
1427  * any automatic read or write of the data is performed.
1428  *
1429  * The strategy routine may return
1430  *
1431  * < 0 - Error occurred (error is passed to user process)
1432  *
1433  * 0   - OK - proceed with automatic read or write.
1434  *
1435  * > 0 - OK - read or write has been done by the strategy routine, so
1436  *       return immediately.
1437  *
1438  * There must be a proc_handler routine for any terminal nodes
1439  * mirrored under /proc/sys (non-terminals are handled by a built-in
1440  * directory handler).  Several default handlers are available to
1441  * cover common cases -
1442  *
1443  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1444  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1445  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1446  *
1447  * It is the handler's job to read the input buffer from user memory
1448  * and process it. The handler should return 0 on success.
1449  *
1450  * This routine returns %NULL on a failure to register, and a pointer
1451  * to the table header on success.
1452  */
1453 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1454 {
1455         struct ctl_table_header *tmp;
1456         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1457         if (!tmp)
1458                 return NULL;
1459         tmp->ctl_table = table;
1460         INIT_LIST_HEAD(&tmp->ctl_entry);
1461         tmp->used = 0;
1462         tmp->unregistering = NULL;
1463         sysctl_set_parent(NULL, table);
1464         spin_lock(&sysctl_lock);
1465         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1466         spin_unlock(&sysctl_lock);
1467         return tmp;
1468 }
1469
1470 /**
1471  * unregister_sysctl_table - unregister a sysctl table hierarchy
1472  * @header: the header returned from register_sysctl_table
1473  *
1474  * Unregisters the sysctl table and all children. proc entries may not
1475  * actually be removed until they are no longer used by anyone.
1476  */
1477 void unregister_sysctl_table(struct ctl_table_header * header)
1478 {
1479         might_sleep();
1480         spin_lock(&sysctl_lock);
1481         start_unregistering(header);
1482         spin_unlock(&sysctl_lock);
1483         kfree(header);
1484 }
1485
1486 #else /* !CONFIG_SYSCTL */
1487 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1488 {
1489         return NULL;
1490 }
1491
1492 void unregister_sysctl_table(struct ctl_table_header * table)
1493 {
1494 }
1495
1496 #endif /* CONFIG_SYSCTL */
1497
1498 /*
1499  * /proc/sys support
1500  */
1501
1502 #ifdef CONFIG_PROC_SYSCTL
1503
1504 static int _proc_do_string(void* data, int maxlen, int write,
1505                            struct file *filp, void __user *buffer,
1506                            size_t *lenp, loff_t *ppos)
1507 {
1508         size_t len;
1509         char __user *p;
1510         char c;
1511
1512         if (!data || !maxlen || !*lenp) {
1513                 *lenp = 0;
1514                 return 0;
1515         }
1516
1517         if (write) {
1518                 len = 0;
1519                 p = buffer;
1520                 while (len < *lenp) {
1521                         if (get_user(c, p++))
1522                                 return -EFAULT;
1523                         if (c == 0 || c == '\n')
1524                                 break;
1525                         len++;
1526                 }
1527                 if (len >= maxlen)
1528                         len = maxlen-1;
1529                 if(copy_from_user(data, buffer, len))
1530                         return -EFAULT;
1531                 ((char *) data)[len] = 0;
1532                 *ppos += *lenp;
1533         } else {
1534                 len = strlen(data);
1535                 if (len > maxlen)
1536                         len = maxlen;
1537
1538                 if (*ppos > len) {
1539                         *lenp = 0;
1540                         return 0;
1541                 }
1542
1543                 data += *ppos;
1544                 len  -= *ppos;
1545
1546                 if (len > *lenp)
1547                         len = *lenp;
1548                 if (len)
1549                         if(copy_to_user(buffer, data, len))
1550                                 return -EFAULT;
1551                 if (len < *lenp) {
1552                         if(put_user('\n', ((char __user *) buffer) + len))
1553                                 return -EFAULT;
1554                         len++;
1555                 }
1556                 *lenp = len;
1557                 *ppos += len;
1558         }
1559         return 0;
1560 }
1561
1562 /**
1563  * proc_dostring - read a string sysctl
1564  * @table: the sysctl table
1565  * @write: %TRUE if this is a write to the sysctl file
1566  * @filp: the file structure
1567  * @buffer: the user buffer
1568  * @lenp: the size of the user buffer
1569  * @ppos: file position
1570  *
1571  * Reads/writes a string from/to the user buffer. If the kernel
1572  * buffer provided is not large enough to hold the string, the
1573  * string is truncated. The copied string is %NULL-terminated.
1574  * If the string is being read by the user process, it is copied
1575  * and a newline '\n' is added. It is truncated if the buffer is
1576  * not large enough.
1577  *
1578  * Returns 0 on success.
1579  */
1580 int proc_dostring(ctl_table *table, int write, struct file *filp,
1581                   void __user *buffer, size_t *lenp, loff_t *ppos)
1582 {
1583         return _proc_do_string(table->data, table->maxlen, write, filp,
1584                                buffer, lenp, ppos);
1585 }
1586
1587
1588 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1589                                  int *valp,
1590                                  int write, void *data)
1591 {
1592         if (write) {
1593                 *valp = *negp ? -*lvalp : *lvalp;
1594         } else {
1595                 int val = *valp;
1596                 if (val < 0) {
1597                         *negp = -1;
1598                         *lvalp = (unsigned long)-val;
1599                 } else {
1600                         *negp = 0;
1601                         *lvalp = (unsigned long)val;
1602                 }
1603         }
1604         return 0;
1605 }
1606
1607 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1608                   int write, struct file *filp, void __user *buffer,
1609                   size_t *lenp, loff_t *ppos,
1610                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1611                               int write, void *data),
1612                   void *data)
1613 {
1614 #define TMPBUFLEN 21
1615         int *i, vleft, first=1, neg, val;
1616         unsigned long lval;
1617         size_t left, len;
1618
1619         char buf[TMPBUFLEN], *p;
1620         char __user *s = buffer;
1621
1622         if (!tbl_data || !table->maxlen || !*lenp ||
1623             (*ppos && !write)) {
1624                 *lenp = 0;
1625                 return 0;
1626         }
1627
1628         i = (int *) tbl_data;
1629         vleft = table->maxlen / sizeof(*i);
1630         left = *lenp;
1631
1632         if (!conv)
1633                 conv = do_proc_dointvec_conv;
1634
1635         for (; left && vleft--; i++, first=0) {
1636                 if (write) {
1637                         while (left) {
1638                                 char c;
1639                                 if (get_user(c, s))
1640                                         return -EFAULT;
1641                                 if (!isspace(c))
1642                                         break;
1643                                 left--;
1644                                 s++;
1645                         }
1646                         if (!left)
1647                                 break;
1648                         neg = 0;
1649                         len = left;
1650                         if (len > sizeof(buf) - 1)
1651                                 len = sizeof(buf) - 1;
1652                         if (copy_from_user(buf, s, len))
1653                                 return -EFAULT;
1654                         buf[len] = 0;
1655                         p = buf;
1656                         if (*p == '-' && left > 1) {
1657                                 neg = 1;
1658                                 p++;
1659                         }
1660                         if (*p < '0' || *p > '9')
1661                                 break;
1662
1663                         lval = simple_strtoul(p, &p, 0);
1664
1665                         len = p-buf;
1666                         if ((len < left) && *p && !isspace(*p))
1667                                 break;
1668                         if (neg)
1669                                 val = -val;
1670                         s += len;
1671                         left -= len;
1672
1673                         if (conv(&neg, &lval, i, 1, data))
1674                                 break;
1675                 } else {
1676                         p = buf;
1677                         if (!first)
1678                                 *p++ = '\t';
1679
1680                         if (conv(&neg, &lval, i, 0, data))
1681                                 break;
1682
1683                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1684                         len = strlen(buf);
1685                         if (len > left)
1686                                 len = left;
1687                         if(copy_to_user(s, buf, len))
1688                                 return -EFAULT;
1689                         left -= len;
1690                         s += len;
1691                 }
1692         }
1693
1694         if (!write && !first && left) {
1695                 if(put_user('\n', s))
1696                         return -EFAULT;
1697                 left--, s++;
1698         }
1699         if (write) {
1700                 while (left) {
1701                         char c;
1702                         if (get_user(c, s++))
1703                                 return -EFAULT;
1704                         if (!isspace(c))
1705                                 break;
1706                         left--;
1707                 }
1708         }
1709         if (write && first)
1710                 return -EINVAL;
1711         *lenp -= left;
1712         *ppos += *lenp;
1713         return 0;
1714 #undef TMPBUFLEN
1715 }
1716
1717 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1718                   void __user *buffer, size_t *lenp, loff_t *ppos,
1719                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1720                               int write, void *data),
1721                   void *data)
1722 {
1723         return __do_proc_dointvec(table->data, table, write, filp,
1724                         buffer, lenp, ppos, conv, data);
1725 }
1726
1727 /**
1728  * proc_dointvec - read a vector of integers
1729  * @table: the sysctl table
1730  * @write: %TRUE if this is a write to the sysctl file
1731  * @filp: the file structure
1732  * @buffer: the user buffer
1733  * @lenp: the size of the user buffer
1734  * @ppos: file position
1735  *
1736  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1737  * values from/to the user buffer, treated as an ASCII string.
1738  *
1739  * Returns 0 on success.
1740  */
1741 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1742                      void __user *buffer, size_t *lenp, loff_t *ppos)
1743 {
1744     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1745                             NULL,NULL);
1746 }
1747
1748 #define OP_SET  0
1749 #define OP_AND  1
1750 #define OP_OR   2
1751
1752 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1753                                       int *valp,
1754                                       int write, void *data)
1755 {
1756         int op = *(int *)data;
1757         if (write) {
1758                 int val = *negp ? -*lvalp : *lvalp;
1759                 switch(op) {
1760                 case OP_SET:    *valp = val; break;
1761                 case OP_AND:    *valp &= val; break;
1762                 case OP_OR:     *valp |= val; break;
1763                 }
1764         } else {
1765                 int val = *valp;
1766                 if (val < 0) {
1767                         *negp = -1;
1768                         *lvalp = (unsigned long)-val;
1769                 } else {
1770                         *negp = 0;
1771                         *lvalp = (unsigned long)val;
1772                 }
1773         }
1774         return 0;
1775 }
1776
1777 /*
1778  *      init may raise the set.
1779  */
1780
1781 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1782                         void __user *buffer, size_t *lenp, loff_t *ppos)
1783 {
1784         int op;
1785
1786         if (write && !capable(CAP_SYS_MODULE)) {
1787                 return -EPERM;
1788         }
1789
1790         op = is_init(current) ? OP_SET : OP_AND;
1791         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1792                                 do_proc_dointvec_bset_conv,&op);
1793 }
1794
1795 /*
1796  *      Taint values can only be increased
1797  */
1798 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1799                                void __user *buffer, size_t *lenp, loff_t *ppos)
1800 {
1801         int op;
1802
1803         if (write && !capable(CAP_SYS_ADMIN))
1804                 return -EPERM;
1805
1806         op = OP_OR;
1807         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1808                                 do_proc_dointvec_bset_conv,&op);
1809 }
1810
1811 struct do_proc_dointvec_minmax_conv_param {
1812         int *min;
1813         int *max;
1814 };
1815
1816 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1817                                         int *valp,
1818                                         int write, void *data)
1819 {
1820         struct do_proc_dointvec_minmax_conv_param *param = data;
1821         if (write) {
1822                 int val = *negp ? -*lvalp : *lvalp;
1823                 if ((param->min && *param->min > val) ||
1824                     (param->max && *param->max < val))
1825                         return -EINVAL;
1826                 *valp = val;
1827         } else {
1828                 int val = *valp;
1829                 if (val < 0) {
1830                         *negp = -1;
1831                         *lvalp = (unsigned long)-val;
1832                 } else {
1833                         *negp = 0;
1834                         *lvalp = (unsigned long)val;
1835                 }
1836         }
1837         return 0;
1838 }
1839
1840 /**
1841  * proc_dointvec_minmax - read a vector of integers with min/max values
1842  * @table: the sysctl table
1843  * @write: %TRUE if this is a write to the sysctl file
1844  * @filp: the file structure
1845  * @buffer: the user buffer
1846  * @lenp: the size of the user buffer
1847  * @ppos: file position
1848  *
1849  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1850  * values from/to the user buffer, treated as an ASCII string.
1851  *
1852  * This routine will ensure the values are within the range specified by
1853  * table->extra1 (min) and table->extra2 (max).
1854  *
1855  * Returns 0 on success.
1856  */
1857 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1858                   void __user *buffer, size_t *lenp, loff_t *ppos)
1859 {
1860         struct do_proc_dointvec_minmax_conv_param param = {
1861                 .min = (int *) table->extra1,
1862                 .max = (int *) table->extra2,
1863         };
1864         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1865                                 do_proc_dointvec_minmax_conv, &param);
1866 }
1867
1868 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1869                                      struct file *filp,
1870                                      void __user *buffer,
1871                                      size_t *lenp, loff_t *ppos,
1872                                      unsigned long convmul,
1873                                      unsigned long convdiv)
1874 {
1875 #define TMPBUFLEN 21
1876         unsigned long *i, *min, *max, val;
1877         int vleft, first=1, neg;
1878         size_t len, left;
1879         char buf[TMPBUFLEN], *p;
1880         char __user *s = buffer;
1881
1882         if (!data || !table->maxlen || !*lenp ||
1883             (*ppos && !write)) {
1884                 *lenp = 0;
1885                 return 0;
1886         }
1887
1888         i = (unsigned long *) data;
1889         min = (unsigned long *) table->extra1;
1890         max = (unsigned long *) table->extra2;
1891         vleft = table->maxlen / sizeof(unsigned long);
1892         left = *lenp;
1893
1894         for (; left && vleft--; i++, min++, max++, first=0) {
1895                 if (write) {
1896                         while (left) {
1897                                 char c;
1898                                 if (get_user(c, s))
1899                                         return -EFAULT;
1900                                 if (!isspace(c))
1901                                         break;
1902                                 left--;
1903                                 s++;
1904                         }
1905                         if (!left)
1906                                 break;
1907                         neg = 0;
1908                         len = left;
1909                         if (len > TMPBUFLEN-1)
1910                                 len = TMPBUFLEN-1;
1911                         if (copy_from_user(buf, s, len))
1912                                 return -EFAULT;
1913                         buf[len] = 0;
1914                         p = buf;
1915                         if (*p == '-' && left > 1) {
1916                                 neg = 1;
1917                                 p++;
1918                         }
1919                         if (*p < '0' || *p > '9')
1920                                 break;
1921                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1922                         len = p-buf;
1923                         if ((len < left) && *p && !isspace(*p))
1924                                 break;
1925                         if (neg)
1926                                 val = -val;
1927                         s += len;
1928                         left -= len;
1929
1930                         if(neg)
1931                                 continue;
1932                         if ((min && val < *min) || (max && val > *max))
1933                                 continue;
1934                         *i = val;
1935                 } else {
1936                         p = buf;
1937                         if (!first)
1938                                 *p++ = '\t';
1939                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1940                         len = strlen(buf);
1941                         if (len > left)
1942                                 len = left;
1943                         if(copy_to_user(s, buf, len))
1944                                 return -EFAULT;
1945                         left -= len;
1946                         s += len;
1947                 }
1948         }
1949
1950         if (!write && !first && left) {
1951                 if(put_user('\n', s))
1952                         return -EFAULT;
1953                 left--, s++;
1954         }
1955         if (write) {
1956                 while (left) {
1957                         char c;
1958                         if (get_user(c, s++))
1959                                 return -EFAULT;
1960                         if (!isspace(c))
1961                                 break;
1962                         left--;
1963                 }
1964         }
1965         if (write && first)
1966                 return -EINVAL;
1967         *lenp -= left;
1968         *ppos += *lenp;
1969         return 0;
1970 #undef TMPBUFLEN
1971 }
1972
1973 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1974                                      struct file *filp,
1975                                      void __user *buffer,
1976                                      size_t *lenp, loff_t *ppos,
1977                                      unsigned long convmul,
1978                                      unsigned long convdiv)
1979 {
1980         return __do_proc_doulongvec_minmax(table->data, table, write,
1981                         filp, buffer, lenp, ppos, convmul, convdiv);
1982 }
1983
1984 /**
1985  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1986  * @table: the sysctl table
1987  * @write: %TRUE if this is a write to the sysctl file
1988  * @filp: the file structure
1989  * @buffer: the user buffer
1990  * @lenp: the size of the user buffer
1991  * @ppos: file position
1992  *
1993  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1994  * values from/to the user buffer, treated as an ASCII string.
1995  *
1996  * This routine will ensure the values are within the range specified by
1997  * table->extra1 (min) and table->extra2 (max).
1998  *
1999  * Returns 0 on success.
2000  */
2001 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2002                            void __user *buffer, size_t *lenp, loff_t *ppos)
2003 {
2004     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2005 }
2006
2007 /**
2008  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2009  * @table: the sysctl table
2010  * @write: %TRUE if this is a write to the sysctl file
2011  * @filp: the file structure
2012  * @buffer: the user buffer
2013  * @lenp: the size of the user buffer
2014  * @ppos: file position
2015  *
2016  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2017  * values from/to the user buffer, treated as an ASCII string. The values
2018  * are treated as milliseconds, and converted to jiffies when they are stored.
2019  *
2020  * This routine will ensure the values are within the range specified by
2021  * table->extra1 (min) and table->extra2 (max).
2022  *
2023  * Returns 0 on success.
2024  */
2025 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2026                                       struct file *filp,
2027                                       void __user *buffer,
2028                                       size_t *lenp, loff_t *ppos)
2029 {
2030     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2031                                      lenp, ppos, HZ, 1000l);
2032 }
2033
2034
2035 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2036                                          int *valp,
2037                                          int write, void *data)
2038 {
2039         if (write) {
2040                 if (*lvalp > LONG_MAX / HZ)
2041                         return 1;
2042                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2043         } else {
2044                 int val = *valp;
2045                 unsigned long lval;
2046                 if (val < 0) {
2047                         *negp = -1;
2048                         lval = (unsigned long)-val;
2049                 } else {
2050                         *negp = 0;
2051                         lval = (unsigned long)val;
2052                 }
2053                 *lvalp = lval / HZ;
2054         }
2055         return 0;
2056 }
2057
2058 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2059                                                 int *valp,
2060                                                 int write, void *data)
2061 {
2062         if (write) {
2063                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2064                         return 1;
2065                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2066         } else {
2067                 int val = *valp;
2068                 unsigned long lval;
2069                 if (val < 0) {
2070                         *negp = -1;
2071                         lval = (unsigned long)-val;
2072                 } else {
2073                         *negp = 0;
2074                         lval = (unsigned long)val;
2075                 }
2076                 *lvalp = jiffies_to_clock_t(lval);
2077         }
2078         return 0;
2079 }
2080
2081 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2082                                             int *valp,
2083                                             int write, void *data)
2084 {
2085         if (write) {
2086                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2087         } else {
2088                 int val = *valp;
2089                 unsigned long lval;
2090                 if (val < 0) {
2091                         *negp = -1;
2092                         lval = (unsigned long)-val;
2093                 } else {
2094                         *negp = 0;
2095                         lval = (unsigned long)val;
2096                 }
2097                 *lvalp = jiffies_to_msecs(lval);
2098         }
2099         return 0;
2100 }
2101
2102 /**
2103  * proc_dointvec_jiffies - read a vector of integers as seconds
2104  * @table: the sysctl table
2105  * @write: %TRUE if this is a write to the sysctl file
2106  * @filp: the file structure
2107  * @buffer: the user buffer
2108  * @lenp: the size of the user buffer
2109  * @ppos: file position
2110  *
2111  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2112  * values from/to the user buffer, treated as an ASCII string.
2113  * The values read are assumed to be in seconds, and are converted into
2114  * jiffies.
2115  *
2116  * Returns 0 on success.
2117  */
2118 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2119                           void __user *buffer, size_t *lenp, loff_t *ppos)
2120 {
2121     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2122                             do_proc_dointvec_jiffies_conv,NULL);
2123 }
2124
2125 /**
2126  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2127  * @table: the sysctl table
2128  * @write: %TRUE if this is a write to the sysctl file
2129  * @filp: the file structure
2130  * @buffer: the user buffer
2131  * @lenp: the size of the user buffer
2132  * @ppos: pointer to the file position
2133  *
2134  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2135  * values from/to the user buffer, treated as an ASCII string.
2136  * The values read are assumed to be in 1/USER_HZ seconds, and
2137  * are converted into jiffies.
2138  *
2139  * Returns 0 on success.
2140  */
2141 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2142                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2143 {
2144     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2145                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2146 }
2147
2148 /**
2149  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2150  * @table: the sysctl table
2151  * @write: %TRUE if this is a write to the sysctl file
2152  * @filp: the file structure
2153  * @buffer: the user buffer
2154  * @lenp: the size of the user buffer
2155  * @ppos: file position
2156  * @ppos: the current position in the file
2157  *
2158  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2159  * values from/to the user buffer, treated as an ASCII string.
2160  * The values read are assumed to be in 1/1000 seconds, and
2161  * are converted into jiffies.
2162  *
2163  * Returns 0 on success.
2164  */
2165 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2166                              void __user *buffer, size_t *lenp, loff_t *ppos)
2167 {
2168         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2169                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2170 }
2171
2172 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2173                            void __user *buffer, size_t *lenp, loff_t *ppos)
2174 {
2175         struct pid *new_pid;
2176         pid_t tmp;
2177         int r;
2178
2179         tmp = pid_nr(cad_pid);
2180
2181         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2182                                lenp, ppos, NULL, NULL);
2183         if (r || !write)
2184                 return r;
2185
2186         new_pid = find_get_pid(tmp);
2187         if (!new_pid)
2188                 return -ESRCH;
2189
2190         put_pid(xchg(&cad_pid, new_pid));
2191         return 0;
2192 }
2193
2194 #else /* CONFIG_PROC_FS */
2195
2196 int proc_dostring(ctl_table *table, int write, struct file *filp,
2197                   void __user *buffer, size_t *lenp, loff_t *ppos)
2198 {
2199         return -ENOSYS;
2200 }
2201
2202 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2203                   void __user *buffer, size_t *lenp, loff_t *ppos)
2204 {
2205         return -ENOSYS;
2206 }
2207
2208 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2209                         void __user *buffer, size_t *lenp, loff_t *ppos)
2210 {
2211         return -ENOSYS;
2212 }
2213
2214 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2215                     void __user *buffer, size_t *lenp, loff_t *ppos)
2216 {
2217         return -ENOSYS;
2218 }
2219
2220 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2221                     void __user *buffer, size_t *lenp, loff_t *ppos)
2222 {
2223         return -ENOSYS;
2224 }
2225
2226 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2227                     void __user *buffer, size_t *lenp, loff_t *ppos)
2228 {
2229         return -ENOSYS;
2230 }
2231
2232 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2233                              void __user *buffer, size_t *lenp, loff_t *ppos)
2234 {
2235         return -ENOSYS;
2236 }
2237
2238 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2239                     void __user *buffer, size_t *lenp, loff_t *ppos)
2240 {
2241         return -ENOSYS;
2242 }
2243
2244 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2245                                       struct file *filp,
2246                                       void __user *buffer,
2247                                       size_t *lenp, loff_t *ppos)
2248 {
2249     return -ENOSYS;
2250 }
2251
2252
2253 #endif /* CONFIG_PROC_FS */
2254
2255
2256 #ifdef CONFIG_SYSCTL_SYSCALL
2257 /*
2258  * General sysctl support routines
2259  */
2260
2261 /* The generic string strategy routine: */
2262 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2263                   void __user *oldval, size_t __user *oldlenp,
2264                   void __user *newval, size_t newlen)
2265 {
2266         if (!table->data || !table->maxlen)
2267                 return -ENOTDIR;
2268
2269         if (oldval && oldlenp) {
2270                 size_t bufsize;
2271                 if (get_user(bufsize, oldlenp))
2272                         return -EFAULT;
2273                 if (bufsize) {
2274                         size_t len = strlen(table->data), copied;
2275
2276                         /* This shouldn't trigger for a well-formed sysctl */
2277                         if (len > table->maxlen)
2278                                 len = table->maxlen;
2279
2280                         /* Copy up to a max of bufsize-1 bytes of the string */
2281                         copied = (len >= bufsize) ? bufsize - 1 : len;
2282
2283                         if (copy_to_user(oldval, table->data, copied) ||
2284                             put_user(0, (char __user *)(oldval + copied)))
2285                                 return -EFAULT;
2286                         if (put_user(len, oldlenp))
2287                                 return -EFAULT;
2288                 }
2289         }
2290         if (newval && newlen) {
2291                 size_t len = newlen;
2292                 if (len > table->maxlen)
2293                         len = table->maxlen;
2294                 if(copy_from_user(table->data, newval, len))
2295                         return -EFAULT;
2296                 if (len == table->maxlen)
2297                         len--;
2298                 ((char *) table->data)[len] = 0;
2299         }
2300         return 1;
2301 }
2302
2303 /*
2304  * This function makes sure that all of the integers in the vector
2305  * are between the minimum and maximum values given in the arrays
2306  * table->extra1 and table->extra2, respectively.
2307  */
2308 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2309                 void __user *oldval, size_t __user *oldlenp,
2310                 void __user *newval, size_t newlen)
2311 {
2312
2313         if (newval && newlen) {
2314                 int __user *vec = (int __user *) newval;
2315                 int *min = (int *) table->extra1;
2316                 int *max = (int *) table->extra2;
2317                 size_t length;
2318                 int i;
2319
2320                 if (newlen % sizeof(int) != 0)
2321                         return -EINVAL;
2322
2323                 if (!table->extra1 && !table->extra2)
2324                         return 0;
2325
2326                 if (newlen > table->maxlen)
2327                         newlen = table->maxlen;
2328                 length = newlen / sizeof(int);
2329
2330                 for (i = 0; i < length; i++) {
2331                         int value;
2332                         if (get_user(value, vec + i))
2333                                 return -EFAULT;
2334                         if (min && value < min[i])
2335                                 return -EINVAL;
2336                         if (max && value > max[i])
2337                                 return -EINVAL;
2338                 }
2339         }
2340         return 0;
2341 }
2342
2343 /* Strategy function to convert jiffies to seconds */
2344 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2345                 void __user *oldval, size_t __user *oldlenp,
2346                 void __user *newval, size_t newlen)
2347 {
2348         if (oldval && oldlenp) {
2349                 size_t olen;
2350
2351                 if (get_user(olen, oldlenp))
2352                         return -EFAULT;
2353                 if (olen) {
2354                         int val;
2355
2356                         if (olen < sizeof(int))
2357                                 return -EINVAL;
2358
2359                         val = *(int *)(table->data) / HZ;
2360                         if (put_user(val, (int __user *)oldval))
2361                                 return -EFAULT;
2362                         if (put_user(sizeof(int), oldlenp))
2363                                 return -EFAULT;
2364                 }
2365         }
2366         if (newval && newlen) {
2367                 int new;
2368                 if (newlen != sizeof(int))
2369                         return -EINVAL;
2370                 if (get_user(new, (int __user *)newval))
2371                         return -EFAULT;
2372                 *(int *)(table->data) = new*HZ;
2373         }
2374         return 1;
2375 }
2376
2377 /* Strategy function to convert jiffies to seconds */
2378 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2379                 void __user *oldval, size_t __user *oldlenp,
2380                 void __user *newval, size_t newlen)
2381 {
2382         if (oldval && oldlenp) {
2383                 size_t olen;
2384
2385                 if (get_user(olen, oldlenp))
2386                         return -EFAULT;
2387                 if (olen) {
2388                         int val;
2389
2390                         if (olen < sizeof(int))
2391                                 return -EINVAL;
2392
2393                         val = jiffies_to_msecs(*(int *)(table->data));
2394                         if (put_user(val, (int __user *)oldval))
2395                                 return -EFAULT;
2396                         if (put_user(sizeof(int), oldlenp))
2397                                 return -EFAULT;
2398                 }
2399         }
2400         if (newval && newlen) {
2401                 int new;
2402                 if (newlen != sizeof(int))
2403                         return -EINVAL;
2404                 if (get_user(new, (int __user *)newval))
2405                         return -EFAULT;
2406                 *(int *)(table->data) = msecs_to_jiffies(new);
2407         }
2408         return 1;
2409 }
2410
2411
2412
2413 #else /* CONFIG_SYSCTL_SYSCALL */
2414
2415
2416 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2417 {
2418         static int msg_count;
2419         struct __sysctl_args tmp;
2420         int name[CTL_MAXNAME];
2421         int i;
2422
2423         /* Read in the sysctl name for better debug message logging */
2424         if (copy_from_user(&tmp, args, sizeof(tmp)))
2425                 return -EFAULT;
2426         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2427                 return -ENOTDIR;
2428         for (i = 0; i < tmp.nlen; i++)
2429                 if (get_user(name[i], tmp.name + i))
2430                         return -EFAULT;
2431
2432         /* Ignore accesses to kernel.version */
2433         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2434                 goto out;
2435
2436         if (msg_count < 5) {
2437                 msg_count++;
2438                 printk(KERN_INFO
2439                         "warning: process `%s' used the removed sysctl "
2440                         "system call with ", current->comm);
2441                 for (i = 0; i < tmp.nlen; i++)
2442                         printk("%d.", name[i]);
2443                 printk("\n");
2444         }
2445 out:
2446         return -ENOSYS;
2447 }
2448
2449 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2450                   void __user *oldval, size_t __user *oldlenp,
2451                   void __user *newval, size_t newlen)
2452 {
2453         return -ENOSYS;
2454 }
2455
2456 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2457                 void __user *oldval, size_t __user *oldlenp,
2458                 void __user *newval, size_t newlen)
2459 {
2460         return -ENOSYS;
2461 }
2462
2463 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2464                 void __user *oldval, size_t __user *oldlenp,
2465                 void __user *newval, size_t newlen)
2466 {
2467         return -ENOSYS;
2468 }
2469
2470 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2471                 void __user *oldval, size_t __user *oldlenp,
2472                 void __user *newval, size_t newlen)
2473 {
2474         return -ENOSYS;
2475 }
2476
2477 #endif /* CONFIG_SYSCTL_SYSCALL */
2478
2479 /*
2480  * No sense putting this after each symbol definition, twice,
2481  * exception granted :-)
2482  */
2483 EXPORT_SYMBOL(proc_dointvec);
2484 EXPORT_SYMBOL(proc_dointvec_jiffies);
2485 EXPORT_SYMBOL(proc_dointvec_minmax);
2486 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2487 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2488 EXPORT_SYMBOL(proc_dostring);
2489 EXPORT_SYMBOL(proc_doulongvec_minmax);
2490 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2491 EXPORT_SYMBOL(register_sysctl_table);
2492 EXPORT_SYMBOL(sysctl_intvec);
2493 EXPORT_SYMBOL(sysctl_jiffies);
2494 EXPORT_SYMBOL(sysctl_ms_jiffies);
2495 EXPORT_SYMBOL(sysctl_string);
2496 EXPORT_SYMBOL(unregister_sysctl_table);