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/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/security.h>
  42 #include <linux/initrd.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50
  51 #include <asm/uaccess.h>
  52 #include <asm/processor.h>
  53
  54 #ifdef CONFIG_X86
  55 #include <asm/nmi.h>
  56 #include <asm/stacktrace.h>
  57 #endif
  58
  59 #if defined(CONFIG_SYSCTL)
  60
  61 /* External variables not in a header file. */
  62 extern int C_A_D;
  63 extern int print_fatal_signals;
  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 extern int audit_argv_kb;
  82
  83 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  84 static int maxolduid = 65535;
  85 static int minolduid;
  86 static int min_percpu_pagelist_fract = 8;
  87
  88 static int ngroups_max = NGROUPS_MAX;
  89
  90 #ifdef CONFIG_KMOD
  91 extern char modprobe_path[];
  92 #endif
  93 #ifdef CONFIG_CHR_DEV_SG
  94 extern int sg_big_buff;
  95 #endif
  96
  97 #ifdef __sparc__
  98 extern char reboot_command [];
  99 extern int stop_a_enabled;
 100 extern int scons_pwroff;
 101 #endif
 102
 103 #ifdef __hppa__
 104 extern int pwrsw_enabled;
 105 extern int unaligned_enabled;
 106 #endif
 107
 108 #ifdef CONFIG_S390
 109 #ifdef CONFIG_MATHEMU
 110 extern int sysctl_ieee_emulation_warnings;
 111 #endif
 112 extern int sysctl_userprocess_debug;
 113 extern int spin_retry;
 114 #endif
 115
 116 extern int sysctl_hz_timer;
 117
 118 #ifdef CONFIG_BSD_PROCESS_ACCT
 119 extern int acct_parm[];
 120 #endif
 121
 122 #ifdef CONFIG_IA64
 123 extern int no_unaligned_warning;
 124 #endif
 125
 126 #ifdef CONFIG_RT_MUTEXES
 127 extern int max_lock_depth;
 128 #endif
 129
 130 #ifdef CONFIG_SYSCTL_SYSCALL
 131 static int parse_table(int __user *, int, void __user *, size_t __user *,
 132                 void __user *, size_t, ctl_table *);
 133 #endif
 134
 135
 136 #ifdef CONFIG_PROC_SYSCTL
 137 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 138                   void __user *buffer, size_t *lenp, loff_t *ppos);
 139 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 140                                void __user *buffer, size_t *lenp, loff_t *ppos);
 141 #endif
 142
 143 static ctl_table root_table[];
 144 static struct ctl_table_header root_table_header =
 145         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 146
 147 static ctl_table kern_table[];
 148 static ctl_table vm_table[];
 149 static ctl_table fs_table[];
 150 static ctl_table debug_table[];
 151 static ctl_table dev_table[];
 152 extern ctl_table random_table[];
 153 #ifdef CONFIG_UNIX98_PTYS
 154 extern ctl_table pty_table[];
 155 #endif
 156 #ifdef CONFIG_INOTIFY_USER
 157 extern ctl_table inotify_table[];
 158 #endif
 159
 160 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 161 int sysctl_legacy_va_layout;
 162 #endif
 163
 164
 165 /* The default sysctl tables: */
 166
 167 static ctl_table root_table[] = {
 168         {
 169                 .ctl_name       = CTL_KERN,
 170                 .procname       = "kernel",
 171                 .mode           = 0555,
 172                 .child          = kern_table,
 173         },
 174         {
 175                 .ctl_name       = CTL_VM,
 176                 .procname       = "vm",
 177                 .mode           = 0555,
 178                 .child          = vm_table,
 179         },
 180 #ifdef CONFIG_NET
 181         {
 182                 .ctl_name       = CTL_NET,
 183                 .procname       = "net",
 184                 .mode           = 0555,
 185                 .child          = net_table,
 186         },
 187 #endif
 188         {
 189                 .ctl_name       = CTL_FS,
 190                 .procname       = "fs",
 191                 .mode           = 0555,
 192                 .child          = fs_table,
 193         },
 194         {
 195                 .ctl_name       = CTL_DEBUG,
 196                 .procname       = "debug",
 197                 .mode           = 0555,
 198                 .child          = debug_table,
 199         },
 200         {
 201                 .ctl_name       = CTL_DEV,
 202                 .procname       = "dev",
 203                 .mode           = 0555,
 204                 .child          = dev_table,
 205         },
 206 /*
 207  * NOTE: do not add new entries to this table unless you have read
 208  * Documentation/sysctl/ctl_unnumbered.txt
 209  */
 210         { .ctl_name = 0 }
 211 };
 212
 213 #ifdef CONFIG_SCHED_DEBUG
 214 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 215 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 216 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 217 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 218 #endif
 219
 220 static ctl_table kern_table[] = {
 221 #ifdef CONFIG_SCHED_DEBUG
 222         {
 223                 .ctl_name       = CTL_UNNUMBERED,
 224                 .procname       = "sched_granularity_ns",
 225                 .data           = &sysctl_sched_granularity,
 226                 .maxlen         = sizeof(unsigned int),
 227                 .mode           = 0644,
 228                 .proc_handler   = &proc_dointvec_minmax,
 229                 .strategy       = &sysctl_intvec,
 230                 .extra1         = &min_sched_granularity_ns,
 231                 .extra2         = &max_sched_granularity_ns,
 232         },
 233         {
 234                 .ctl_name       = CTL_UNNUMBERED,
 235                 .procname       = "sched_wakeup_granularity_ns",
 236                 .data           = &sysctl_sched_wakeup_granularity,
 237                 .maxlen         = sizeof(unsigned int),
 238                 .mode           = 0644,
 239                 .proc_handler   = &proc_dointvec_minmax,
 240                 .strategy       = &sysctl_intvec,
 241                 .extra1         = &min_wakeup_granularity_ns,
 242                 .extra2         = &max_wakeup_granularity_ns,
 243         },
 244         {
 245                 .ctl_name       = CTL_UNNUMBERED,
 246                 .procname       = "sched_batch_wakeup_granularity_ns",
 247                 .data           = &sysctl_sched_batch_wakeup_granularity,
 248                 .maxlen         = sizeof(unsigned int),
 249                 .mode           = 0644,
 250                 .proc_handler   = &proc_dointvec_minmax,
 251                 .strategy       = &sysctl_intvec,
 252                 .extra1         = &min_wakeup_granularity_ns,
 253                 .extra2         = &max_wakeup_granularity_ns,
 254         },
 255         {
 256                 .ctl_name       = CTL_UNNUMBERED,
 257                 .procname       = "sched_stat_granularity_ns",
 258                 .data           = &sysctl_sched_stat_granularity,
 259                 .maxlen         = sizeof(unsigned int),
 260                 .mode           = 0644,
 261                 .proc_handler   = &proc_dointvec_minmax,
 262                 .strategy       = &sysctl_intvec,
 263                 .extra1         = &min_wakeup_granularity_ns,
 264                 .extra2         = &max_wakeup_granularity_ns,
 265         },
 266         {
 267                 .ctl_name       = CTL_UNNUMBERED,
 268                 .procname       = "sched_runtime_limit_ns",
 269                 .data           = &sysctl_sched_runtime_limit,
 270                 .maxlen         = sizeof(unsigned int),
 271                 .mode           = 0644,
 272                 .proc_handler   = &proc_dointvec_minmax,
 273                 .strategy       = &sysctl_intvec,
 274                 .extra1         = &min_sched_granularity_ns,
 275                 .extra2         = &max_sched_granularity_ns,
 276         },
 277         {
 278                 .ctl_name       = CTL_UNNUMBERED,
 279                 .procname       = "sched_child_runs_first",
 280                 .data           = &sysctl_sched_child_runs_first,
 281                 .maxlen         = sizeof(unsigned int),
 282                 .mode           = 0644,
 283                 .proc_handler   = &proc_dointvec,
 284         },
 285         {
 286                 .ctl_name       = CTL_UNNUMBERED,
 287                 .procname       = "sched_features",
 288                 .data           = &sysctl_sched_features,
 289                 .maxlen         = sizeof(unsigned int),
 290                 .mode           = 0644,
 291                 .proc_handler   = &proc_dointvec,
 292         },
 293 #endif
 294         {
 295                 .ctl_name       = KERN_PANIC,
 296                 .procname       = "panic",
 297                 .data           = &panic_timeout,
 298                 .maxlen         = sizeof(int),
 299                 .mode           = 0644,
 300                 .proc_handler   = &proc_dointvec,
 301         },
 302         {
 303                 .ctl_name       = KERN_CORE_USES_PID,
 304                 .procname       = "core_uses_pid",
 305                 .data           = &core_uses_pid,
 306                 .maxlen         = sizeof(int),
 307                 .mode           = 0644,
 308                 .proc_handler   = &proc_dointvec,
 309         },
 310 #ifdef CONFIG_AUDITSYSCALL
 311         {
 312                 .ctl_name       = CTL_UNNUMBERED,
 313                 .procname       = "audit_argv_kb",
 314                 .data           = &audit_argv_kb,
 315                 .maxlen         = sizeof(int),
 316                 .mode           = 0644,
 317                 .proc_handler   = &proc_dointvec,
 318         },
 319 #endif
 320         {
 321                 .ctl_name       = KERN_CORE_PATTERN,
 322                 .procname       = "core_pattern",
 323                 .data           = core_pattern,
 324                 .maxlen         = CORENAME_MAX_SIZE,
 325                 .mode           = 0644,
 326                 .proc_handler   = &proc_dostring,
 327                 .strategy       = &sysctl_string,
 328         },
 329 #ifdef CONFIG_PROC_SYSCTL
 330         {
 331                 .ctl_name       = KERN_TAINTED,
 332                 .procname       = "tainted",
 333                 .data           = &tainted,
 334                 .maxlen         = sizeof(int),
 335                 .mode           = 0644,
 336                 .proc_handler   = &proc_dointvec_taint,
 337         },
 338 #endif
 339         {
 340                 .ctl_name       = KERN_CAP_BSET,
 341                 .procname       = "cap-bound",
 342                 .data           = &cap_bset,
 343                 .maxlen         = sizeof(kernel_cap_t),
 344                 .mode           = 0600,
 345                 .proc_handler   = &proc_dointvec_bset,
 346         },
 347 #ifdef CONFIG_BLK_DEV_INITRD
 348         {
 349                 .ctl_name       = KERN_REALROOTDEV,
 350                 .procname       = "real-root-dev",
 351                 .data           = &real_root_dev,
 352                 .maxlen         = sizeof(int),
 353                 .mode           = 0644,
 354                 .proc_handler   = &proc_dointvec,
 355         },
 356 #endif
 357         {
 358                 .ctl_name       = CTL_UNNUMBERED,
 359                 .procname       = "print-fatal-signals",
 360                 .data           = &print_fatal_signals,
 361                 .maxlen         = sizeof(int),
 362                 .mode           = 0644,
 363                 .proc_handler   = &proc_dointvec,
 364         },
 365 #ifdef __sparc__
 366         {
 367                 .ctl_name       = KERN_SPARC_REBOOT,
 368                 .procname       = "reboot-cmd",
 369                 .data           = reboot_command,
 370                 .maxlen         = 256,
 371                 .mode           = 0644,
 372                 .proc_handler   = &proc_dostring,
 373                 .strategy       = &sysctl_string,
 374         },
 375         {
 376                 .ctl_name       = KERN_SPARC_STOP_A,
 377                 .procname       = "stop-a",
 378                 .data           = &stop_a_enabled,
 379                 .maxlen         = sizeof (int),
 380                 .mode           = 0644,
 381                 .proc_handler   = &proc_dointvec,
 382         },
 383         {
 384                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 385                 .procname       = "scons-poweroff",
 386                 .data           = &scons_pwroff,
 387                 .maxlen         = sizeof (int),
 388                 .mode           = 0644,
 389                 .proc_handler   = &proc_dointvec,
 390         },
 391 #endif
 392 #ifdef __hppa__
 393         {
 394                 .ctl_name       = KERN_HPPA_PWRSW,
 395                 .procname       = "soft-power",
 396                 .data           = &pwrsw_enabled,
 397                 .maxlen         = sizeof (int),
 398                 .mode           = 0644,
 399                 .proc_handler   = &proc_dointvec,
 400         },
 401         {
 402                 .ctl_name       = KERN_HPPA_UNALIGNED,
 403                 .procname       = "unaligned-trap",
 404                 .data           = &unaligned_enabled,
 405                 .maxlen         = sizeof (int),
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_dointvec,
 408         },
 409 #endif
 410         {
 411                 .ctl_name       = KERN_CTLALTDEL,
 412                 .procname       = "ctrl-alt-del",
 413                 .data           = &C_A_D,
 414                 .maxlen         = sizeof(int),
 415                 .mode           = 0644,
 416                 .proc_handler   = &proc_dointvec,
 417         },
 418         {
 419                 .ctl_name       = KERN_PRINTK,
 420                 .procname       = "printk",
 421                 .data           = &console_loglevel,
 422                 .maxlen         = 4*sizeof(int),
 423                 .mode           = 0644,
 424                 .proc_handler   = &proc_dointvec,
 425         },
 426 #ifdef CONFIG_KMOD
 427         {
 428                 .ctl_name       = KERN_MODPROBE,
 429                 .procname       = "modprobe",
 430                 .data           = &modprobe_path,
 431                 .maxlen         = KMOD_PATH_LEN,
 432                 .mode           = 0644,
 433                 .proc_handler   = &proc_dostring,
 434                 .strategy       = &sysctl_string,
 435         },
 436 #endif
 437 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 438         {
 439                 .ctl_name       = KERN_HOTPLUG,
 440                 .procname       = "hotplug",
 441                 .data           = &uevent_helper,
 442                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 443                 .mode           = 0644,
 444                 .proc_handler   = &proc_dostring,
 445                 .strategy       = &sysctl_string,
 446         },
 447 #endif
 448 #ifdef CONFIG_CHR_DEV_SG
 449         {
 450                 .ctl_name       = KERN_SG_BIG_BUFF,
 451                 .procname       = "sg-big-buff",
 452                 .data           = &sg_big_buff,
 453                 .maxlen         = sizeof (int),
 454                 .mode           = 0444,
 455                 .proc_handler   = &proc_dointvec,
 456         },
 457 #endif
 458 #ifdef CONFIG_BSD_PROCESS_ACCT
 459         {
 460                 .ctl_name       = KERN_ACCT,
 461                 .procname       = "acct",
 462                 .data           = &acct_parm,
 463                 .maxlen         = 3*sizeof(int),
 464                 .mode           = 0644,
 465                 .proc_handler   = &proc_dointvec,
 466         },
 467 #endif
 468 #ifdef CONFIG_MAGIC_SYSRQ
 469         {
 470                 .ctl_name       = KERN_SYSRQ,
 471                 .procname       = "sysrq",
 472                 .data           = &__sysrq_enabled,
 473                 .maxlen         = sizeof (int),
 474                 .mode           = 0644,
 475                 .proc_handler   = &proc_dointvec,
 476         },
 477 #endif
 478 #ifdef CONFIG_PROC_SYSCTL
 479         {
 480                 .ctl_name       = KERN_CADPID,
 481                 .procname       = "cad_pid",
 482                 .data           = NULL,
 483                 .maxlen         = sizeof (int),
 484                 .mode           = 0600,
 485                 .proc_handler   = &proc_do_cad_pid,
 486         },
 487 #endif
 488         {
 489                 .ctl_name       = KERN_MAX_THREADS,
 490                 .procname       = "threads-max",
 491                 .data           = &max_threads,
 492                 .maxlen         = sizeof(int),
 493                 .mode           = 0644,
 494                 .proc_handler   = &proc_dointvec,
 495         },
 496         {
 497                 .ctl_name       = KERN_RANDOM,
 498                 .procname       = "random",
 499                 .mode           = 0555,
 500                 .child          = random_table,
 501         },
 502 #ifdef CONFIG_UNIX98_PTYS
 503         {
 504                 .ctl_name       = KERN_PTY,
 505                 .procname       = "pty",
 506                 .mode           = 0555,
 507                 .child          = pty_table,
 508         },
 509 #endif
 510         {
 511                 .ctl_name       = KERN_OVERFLOWUID,
 512                 .procname       = "overflowuid",
 513                 .data           = &overflowuid,
 514                 .maxlen         = sizeof(int),
 515                 .mode           = 0644,
 516                 .proc_handler   = &proc_dointvec_minmax,
 517                 .strategy       = &sysctl_intvec,
 518                 .extra1         = &minolduid,
 519                 .extra2         = &maxolduid,
 520         },
 521         {
 522                 .ctl_name       = KERN_OVERFLOWGID,
 523                 .procname       = "overflowgid",
 524                 .data           = &overflowgid,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = &proc_dointvec_minmax,
 528                 .strategy       = &sysctl_intvec,
 529                 .extra1         = &minolduid,
 530                 .extra2         = &maxolduid,
 531         },
 532 #ifdef CONFIG_S390
 533 #ifdef CONFIG_MATHEMU
 534         {
 535                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 536                 .procname       = "ieee_emulation_warnings",
 537                 .data           = &sysctl_ieee_emulation_warnings,
 538                 .maxlen         = sizeof(int),
 539                 .mode           = 0644,
 540                 .proc_handler   = &proc_dointvec,
 541         },
 542 #endif
 543 #ifdef CONFIG_NO_IDLE_HZ
 544         {
 545                 .ctl_name       = KERN_HZ_TIMER,
 546                 .procname       = "hz_timer",
 547                 .data           = &sysctl_hz_timer,
 548                 .maxlen         = sizeof(int),
 549                 .mode           = 0644,
 550                 .proc_handler   = &proc_dointvec,
 551         },
 552 #endif
 553         {
 554                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 555                 .procname       = "userprocess_debug",
 556                 .data           = &sysctl_userprocess_debug,
 557                 .maxlen         = sizeof(int),
 558                 .mode           = 0644,
 559                 .proc_handler   = &proc_dointvec,
 560         },
 561 #endif
 562         {
 563                 .ctl_name       = KERN_PIDMAX,
 564                 .procname       = "pid_max",
 565                 .data           = &pid_max,
 566                 .maxlen         = sizeof (int),
 567                 .mode           = 0644,
 568                 .proc_handler   = &proc_dointvec_minmax,
 569                 .strategy       = sysctl_intvec,
 570                 .extra1         = &pid_max_min,
 571                 .extra2         = &pid_max_max,
 572         },
 573         {
 574                 .ctl_name       = KERN_PANIC_ON_OOPS,
 575                 .procname       = "panic_on_oops",
 576                 .data           = &panic_on_oops,
 577                 .maxlen         = sizeof(int),
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dointvec,
 580         },
 581         {
 582                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 583                 .procname       = "printk_ratelimit",
 584                 .data           = &printk_ratelimit_jiffies,
 585                 .maxlen         = sizeof(int),
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dointvec_jiffies,
 588                 .strategy       = &sysctl_jiffies,
 589         },
 590         {
 591                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 592                 .procname       = "printk_ratelimit_burst",
 593                 .data           = &printk_ratelimit_burst,
 594                 .maxlen         = sizeof(int),
 595                 .mode           = 0644,
 596                 .proc_handler   = &proc_dointvec,
 597         },
 598         {
 599                 .ctl_name       = KERN_NGROUPS_MAX,
 600                 .procname       = "ngroups_max",
 601                 .data           = &ngroups_max,
 602                 .maxlen         = sizeof (int),
 603                 .mode           = 0444,
 604                 .proc_handler   = &proc_dointvec,
 605         },
 606 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 607         {
 608                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 609                 .procname       = "unknown_nmi_panic",
 610                 .data           = &unknown_nmi_panic,
 611                 .maxlen         = sizeof (int),
 612                 .mode           = 0644,
 613                 .proc_handler   = &proc_dointvec,
 614         },
 615         {
 616                 .ctl_name       = KERN_NMI_WATCHDOG,
 617                 .procname       = "nmi_watchdog",
 618                 .data           = &nmi_watchdog_enabled,
 619                 .maxlen         = sizeof (int),
 620                 .mode           = 0644,
 621                 .proc_handler   = &proc_nmi_enabled,
 622         },
 623 #endif
 624 #if defined(CONFIG_X86)
 625         {
 626                 .ctl_name       = KERN_PANIC_ON_NMI,
 627                 .procname       = "panic_on_unrecovered_nmi",
 628                 .data           = &panic_on_unrecovered_nmi,
 629                 .maxlen         = sizeof(int),
 630                 .mode           = 0644,
 631                 .proc_handler   = &proc_dointvec,
 632         },
 633         {
 634                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 635                 .procname       = "bootloader_type",
 636                 .data           = &bootloader_type,
 637                 .maxlen         = sizeof (int),
 638                 .mode           = 0444,
 639                 .proc_handler   = &proc_dointvec,
 640         },
 641         {
 642                 .ctl_name       = CTL_UNNUMBERED,
 643                 .procname       = "kstack_depth_to_print",
 644                 .data           = &kstack_depth_to_print,
 645                 .maxlen         = sizeof(int),
 646                 .mode           = 0644,
 647                 .proc_handler   = &proc_dointvec,
 648         },
 649 #endif
 650 #if defined(CONFIG_MMU)
 651         {
 652                 .ctl_name       = KERN_RANDOMIZE,
 653                 .procname       = "randomize_va_space",
 654                 .data           = &randomize_va_space,
 655                 .maxlen         = sizeof(int),
 656                 .mode           = 0644,
 657                 .proc_handler   = &proc_dointvec,
 658         },
 659 #endif
 660 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 661         {
 662                 .ctl_name       = KERN_SPIN_RETRY,
 663                 .procname       = "spin_retry",
 664                 .data           = &spin_retry,
 665                 .maxlen         = sizeof (int),
 666                 .mode           = 0644,
 667                 .proc_handler   = &proc_dointvec,
 668         },
 669 #endif
 670 #ifdef CONFIG_ACPI_SLEEP
 671         {
 672                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 673                 .procname       = "acpi_video_flags",
 674                 .data           = &acpi_realmode_flags,
 675                 .maxlen         = sizeof (unsigned long),
 676                 .mode           = 0644,
 677                 .proc_handler   = &proc_doulongvec_minmax,
 678         },
 679 #endif
 680 #ifdef CONFIG_IA64
 681         {
 682                 .ctl_name       = KERN_IA64_UNALIGNED,
 683                 .procname       = "ignore-unaligned-usertrap",
 684                 .data           = &no_unaligned_warning,
 685                 .maxlen         = sizeof (int),
 686                 .mode           = 0644,
 687                 .proc_handler   = &proc_dointvec,
 688         },
 689 #endif
 690 #ifdef CONFIG_COMPAT
 691         {
 692                 .ctl_name       = KERN_COMPAT_LOG,
 693                 .procname       = "compat-log",
 694                 .data           = &compat_log,
 695                 .maxlen         = sizeof (int),
 696                 .mode           = 0644,
 697                 .proc_handler   = &proc_dointvec,
 698         },
 699 #endif
 700 #ifdef CONFIG_RT_MUTEXES
 701         {
 702                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 703                 .procname       = "max_lock_depth",
 704                 .data           = &max_lock_depth,
 705                 .maxlen         = sizeof(int),
 706                 .mode           = 0644,
 707                 .proc_handler   = &proc_dointvec,
 708         },
 709 #endif
 710 #ifdef CONFIG_PROC_FS
 711         {
 712                 .ctl_name       = CTL_UNNUMBERED,
 713                 .procname       = "maps_protect",
 714                 .data           = &maps_protect,
 715                 .maxlen         = sizeof(int),
 716                 .mode           = 0644,
 717                 .proc_handler   = &proc_dointvec,
 718         },
 719 #endif
 720         {
 721                 .ctl_name       = CTL_UNNUMBERED,
 722                 .procname       = "poweroff_cmd",
 723                 .data           = &poweroff_cmd,
 724                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 725                 .mode           = 0644,
 726                 .proc_handler   = &proc_dostring,
 727                 .strategy       = &sysctl_string,
 728         },
 729
 730         { .ctl_name = 0 }
 731 };
 732
 733 /* Constants for minimum and maximum testing in vm_table.
 734    We use these as one-element integer vectors. */
 735 static int zero;
 736 static int one_hundred = 100;
 737
 738
 739 static ctl_table vm_table[] = {
 740         {
 741                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 742                 .procname       = "overcommit_memory",
 743                 .data           = &sysctl_overcommit_memory,
 744                 .maxlen         = sizeof(sysctl_overcommit_memory),
 745                 .mode           = 0644,
 746                 .proc_handler   = &proc_dointvec,
 747         },
 748         {
 749                 .ctl_name       = VM_PANIC_ON_OOM,
 750                 .procname       = "panic_on_oom",
 751                 .data           = &sysctl_panic_on_oom,
 752                 .maxlen         = sizeof(sysctl_panic_on_oom),
 753                 .mode           = 0644,
 754                 .proc_handler   = &proc_dointvec,
 755         },
 756         {
 757                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 758                 .procname       = "overcommit_ratio",
 759                 .data           = &sysctl_overcommit_ratio,
 760                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 761                 .mode           = 0644,
 762                 .proc_handler   = &proc_dointvec,
 763         },
 764         {
 765                 .ctl_name       = VM_PAGE_CLUSTER,
 766                 .procname       = "page-cluster",
 767                 .data           = &page_cluster,
 768                 .maxlen         = sizeof(int),
 769                 .mode           = 0644,
 770                 .proc_handler   = &proc_dointvec,
 771         },
 772         {
 773                 .ctl_name       = VM_DIRTY_BACKGROUND,
 774                 .procname       = "dirty_background_ratio",
 775                 .data           = &dirty_background_ratio,
 776                 .maxlen         = sizeof(dirty_background_ratio),
 777                 .mode           = 0644,
 778                 .proc_handler   = &proc_dointvec_minmax,
 779                 .strategy       = &sysctl_intvec,
 780                 .extra1         = &zero,
 781                 .extra2         = &one_hundred,
 782         },
 783         {
 784                 .ctl_name       = VM_DIRTY_RATIO,
 785                 .procname       = "dirty_ratio",
 786                 .data           = &vm_dirty_ratio,
 787                 .maxlen         = sizeof(vm_dirty_ratio),
 788                 .mode           = 0644,
 789                 .proc_handler   = &proc_dointvec_minmax,
 790                 .strategy       = &sysctl_intvec,
 791                 .extra1         = &zero,
 792                 .extra2         = &one_hundred,
 793         },
 794         {
 795                 .ctl_name       = VM_DIRTY_WB_CS,
 796                 .procname       = "dirty_writeback_centisecs",
 797                 .data           = &dirty_writeback_interval,
 798                 .maxlen         = sizeof(dirty_writeback_interval),
 799                 .mode           = 0644,
 800                 .proc_handler   = &dirty_writeback_centisecs_handler,
 801         },
 802         {
 803                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 804                 .procname       = "dirty_expire_centisecs",
 805                 .data           = &dirty_expire_interval,
 806                 .maxlen         = sizeof(dirty_expire_interval),
 807                 .mode           = 0644,
 808                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 809         },
 810         {
 811                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 812                 .procname       = "nr_pdflush_threads",
 813                 .data           = &nr_pdflush_threads,
 814                 .maxlen         = sizeof nr_pdflush_threads,
 815                 .mode           = 0444 /* read-only*/,
 816                 .proc_handler   = &proc_dointvec,
 817         },
 818         {
 819                 .ctl_name       = VM_SWAPPINESS,
 820                 .procname       = "swappiness",
 821                 .data           = &vm_swappiness,
 822                 .maxlen         = sizeof(vm_swappiness),
 823                 .mode           = 0644,
 824                 .proc_handler   = &proc_dointvec_minmax,
 825                 .strategy       = &sysctl_intvec,
 826                 .extra1         = &zero,
 827                 .extra2         = &one_hundred,
 828         },
 829 #ifdef CONFIG_HUGETLB_PAGE
 830          {
 831                 .ctl_name       = VM_HUGETLB_PAGES,
 832                 .procname       = "nr_hugepages",
 833                 .data           = &max_huge_pages,
 834                 .maxlen         = sizeof(unsigned long),
 835                 .mode           = 0644,
 836                 .proc_handler   = &hugetlb_sysctl_handler,
 837                 .extra1         = (void *)&hugetlb_zero,
 838                 .extra2         = (void *)&hugetlb_infinity,
 839          },
 840          {
 841                 .ctl_name       = VM_HUGETLB_GROUP,
 842                 .procname       = "hugetlb_shm_group",
 843                 .data           = &sysctl_hugetlb_shm_group,
 844                 .maxlen         = sizeof(gid_t),
 845                 .mode           = 0644,
 846                 .proc_handler   = &proc_dointvec,
 847          },
 848          {
 849                 .ctl_name       = CTL_UNNUMBERED,
 850                 .procname       = "hugepages_treat_as_movable",
 851                 .data           = &hugepages_treat_as_movable,
 852                 .maxlen         = sizeof(int),
 853                 .mode           = 0644,
 854                 .proc_handler   = &hugetlb_treat_movable_handler,
 855         },
 856 #endif
 857         {
 858                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 859                 .procname       = "lowmem_reserve_ratio",
 860                 .data           = &sysctl_lowmem_reserve_ratio,
 861                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 862                 .mode           = 0644,
 863                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 864                 .strategy       = &sysctl_intvec,
 865         },
 866         {
 867                 .ctl_name       = VM_DROP_PAGECACHE,
 868                 .procname       = "drop_caches",
 869                 .data           = &sysctl_drop_caches,
 870                 .maxlen         = sizeof(int),
 871                 .mode           = 0644,
 872                 .proc_handler   = drop_caches_sysctl_handler,
 873                 .strategy       = &sysctl_intvec,
 874         },
 875         {
 876                 .ctl_name       = VM_MIN_FREE_KBYTES,
 877                 .procname       = "min_free_kbytes",
 878                 .data           = &min_free_kbytes,
 879                 .maxlen         = sizeof(min_free_kbytes),
 880                 .mode           = 0644,
 881                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 882                 .strategy       = &sysctl_intvec,
 883                 .extra1         = &zero,
 884         },
 885         {
 886                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 887                 .procname       = "percpu_pagelist_fraction",
 888                 .data           = &percpu_pagelist_fraction,
 889                 .maxlen         = sizeof(percpu_pagelist_fraction),
 890                 .mode           = 0644,
 891                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 892                 .strategy       = &sysctl_intvec,
 893                 .extra1         = &min_percpu_pagelist_fract,
 894         },
 895 #ifdef CONFIG_MMU
 896         {
 897                 .ctl_name       = VM_MAX_MAP_COUNT,
 898                 .procname       = "max_map_count",
 899                 .data           = &sysctl_max_map_count,
 900                 .maxlen         = sizeof(sysctl_max_map_count),
 901                 .mode           = 0644,
 902                 .proc_handler   = &proc_dointvec
 903         },
 904 #endif
 905         {
 906                 .ctl_name       = VM_LAPTOP_MODE,
 907                 .procname       = "laptop_mode",
 908                 .data           = &laptop_mode,
 909                 .maxlen         = sizeof(laptop_mode),
 910                 .mode           = 0644,
 911                 .proc_handler   = &proc_dointvec_jiffies,
 912                 .strategy       = &sysctl_jiffies,
 913         },
 914         {
 915                 .ctl_name       = VM_BLOCK_DUMP,
 916                 .procname       = "block_dump",
 917                 .data           = &block_dump,
 918                 .maxlen         = sizeof(block_dump),
 919                 .mode           = 0644,
 920                 .proc_handler   = &proc_dointvec,
 921                 .strategy       = &sysctl_intvec,
 922                 .extra1         = &zero,
 923         },
 924         {
 925                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 926                 .procname       = "vfs_cache_pressure",
 927                 .data           = &sysctl_vfs_cache_pressure,
 928                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 929                 .mode           = 0644,
 930                 .proc_handler   = &proc_dointvec,
 931                 .strategy       = &sysctl_intvec,
 932                 .extra1         = &zero,
 933         },
 934 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 935         {
 936                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 937                 .procname       = "legacy_va_layout",
 938                 .data           = &sysctl_legacy_va_layout,
 939                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 940                 .mode           = 0644,
 941                 .proc_handler   = &proc_dointvec,
 942                 .strategy       = &sysctl_intvec,
 943                 .extra1         = &zero,
 944         },
 945 #endif
 946 #ifdef CONFIG_NUMA
 947         {
 948                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 949                 .procname       = "zone_reclaim_mode",
 950                 .data           = &zone_reclaim_mode,
 951                 .maxlen         = sizeof(zone_reclaim_mode),
 952                 .mode           = 0644,
 953                 .proc_handler   = &proc_dointvec,
 954                 .strategy       = &sysctl_intvec,
 955                 .extra1         = &zero,
 956         },
 957         {
 958                 .ctl_name       = VM_MIN_UNMAPPED,
 959                 .procname       = "min_unmapped_ratio",
 960                 .data           = &sysctl_min_unmapped_ratio,
 961                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 962                 .mode           = 0644,
 963                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 964                 .strategy       = &sysctl_intvec,
 965                 .extra1         = &zero,
 966                 .extra2         = &one_hundred,
 967         },
 968         {
 969                 .ctl_name       = VM_MIN_SLAB,
 970                 .procname       = "min_slab_ratio",
 971                 .data           = &sysctl_min_slab_ratio,
 972                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 973                 .mode           = 0644,
 974                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 975                 .strategy       = &sysctl_intvec,
 976                 .extra1         = &zero,
 977                 .extra2         = &one_hundred,
 978         },
 979 #endif
 980 #ifdef CONFIG_SMP
 981         {
 982                 .ctl_name       = CTL_UNNUMBERED,
 983                 .procname       = "stat_interval",
 984                 .data           = &sysctl_stat_interval,
 985                 .maxlen         = sizeof(sysctl_stat_interval),
 986                 .mode           = 0644,
 987                 .proc_handler   = &proc_dointvec_jiffies,
 988                 .strategy       = &sysctl_jiffies,
 989         },
 990 #endif
 991 #ifdef CONFIG_SECURITY
 992         {
 993                 .ctl_name       = CTL_UNNUMBERED,
 994                 .procname       = "mmap_min_addr",
 995                 .data           = &mmap_min_addr,
 996                 .maxlen         = sizeof(unsigned long),
 997                 .mode           = 0644,
 998                 .proc_handler   = &proc_doulongvec_minmax,
 999         },
1000 #ifdef CONFIG_NUMA
1001         {
1002                 .ctl_name       = CTL_UNNUMBERED,
1003                 .procname       = "numa_zonelist_order",
1004                 .data           = &numa_zonelist_order,
1005                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1006                 .mode           = 0644,
1007                 .proc_handler   = &numa_zonelist_order_handler,
1008                 .strategy       = &sysctl_string,
1009         },
1010 #endif
1011 #endif
1012 #if defined(CONFIG_X86_32) || \
1013    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1014         {
1015                 .ctl_name       = VM_VDSO_ENABLED,
1016                 .procname       = "vdso_enabled",
1017                 .data           = &vdso_enabled,
1018                 .maxlen         = sizeof(vdso_enabled),
1019                 .mode           = 0644,
1020                 .proc_handler   = &proc_dointvec,
1021                 .strategy       = &sysctl_intvec,
1022                 .extra1         = &zero,
1023         },
1024 #endif
1025 /*
1026  * NOTE: do not add new entries to this table unless you have read
1027  * Documentation/sysctl/ctl_unnumbered.txt
1028  */
1029         { .ctl_name = 0 }
1030 };
1031
1032 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1033 static ctl_table binfmt_misc_table[] = {
1034         { .ctl_name = 0 }
1035 };
1036 #endif
1037
1038 static ctl_table fs_table[] = {
1039         {
1040                 .ctl_name       = FS_NRINODE,
1041                 .procname       = "inode-nr",
1042                 .data           = &inodes_stat,
1043                 .maxlen         = 2*sizeof(int),
1044                 .mode           = 0444,
1045                 .proc_handler   = &proc_dointvec,
1046         },
1047         {
1048                 .ctl_name       = FS_STATINODE,
1049                 .procname       = "inode-state",
1050                 .data           = &inodes_stat,
1051                 .maxlen         = 7*sizeof(int),
1052                 .mode           = 0444,
1053                 .proc_handler   = &proc_dointvec,
1054         },
1055         {
1056                 .ctl_name       = FS_NRFILE,
1057                 .procname       = "file-nr",
1058                 .data           = &files_stat,
1059                 .maxlen         = 3*sizeof(int),
1060                 .mode           = 0444,
1061                 .proc_handler   = &proc_nr_files,
1062         },
1063         {
1064                 .ctl_name       = FS_MAXFILE,
1065                 .procname       = "file-max",
1066                 .data           = &files_stat.max_files,
1067                 .maxlen         = sizeof(int),
1068                 .mode           = 0644,
1069                 .proc_handler   = &proc_dointvec,
1070         },
1071         {
1072                 .ctl_name       = FS_DENTRY,
1073                 .procname       = "dentry-state",
1074                 .data           = &dentry_stat,
1075                 .maxlen         = 6*sizeof(int),
1076                 .mode           = 0444,
1077                 .proc_handler   = &proc_dointvec,
1078         },
1079         {
1080                 .ctl_name       = FS_OVERFLOWUID,
1081                 .procname       = "overflowuid",
1082                 .data           = &fs_overflowuid,
1083                 .maxlen         = sizeof(int),
1084                 .mode           = 0644,
1085                 .proc_handler   = &proc_dointvec_minmax,
1086                 .strategy       = &sysctl_intvec,
1087                 .extra1         = &minolduid,
1088                 .extra2         = &maxolduid,
1089         },
1090         {
1091                 .ctl_name       = FS_OVERFLOWGID,
1092                 .procname       = "overflowgid",
1093                 .data           = &fs_overflowgid,
1094                 .maxlen         = sizeof(int),
1095                 .mode           = 0644,
1096                 .proc_handler   = &proc_dointvec_minmax,
1097                 .strategy       = &sysctl_intvec,
1098                 .extra1         = &minolduid,
1099                 .extra2         = &maxolduid,
1100         },
1101         {
1102                 .ctl_name       = FS_LEASES,
1103                 .procname       = "leases-enable",
1104                 .data           = &leases_enable,
1105                 .maxlen         = sizeof(int),
1106                 .mode           = 0644,
1107                 .proc_handler   = &proc_dointvec,
1108         },
1109 #ifdef CONFIG_DNOTIFY
1110         {
1111                 .ctl_name       = FS_DIR_NOTIFY,
1112                 .procname       = "dir-notify-enable",
1113                 .data           = &dir_notify_enable,
1114                 .maxlen         = sizeof(int),
1115                 .mode           = 0644,
1116                 .proc_handler   = &proc_dointvec,
1117         },
1118 #endif
1119 #ifdef CONFIG_MMU
1120         {
1121                 .ctl_name       = FS_LEASE_TIME,
1122                 .procname       = "lease-break-time",
1123                 .data           = &lease_break_time,
1124                 .maxlen         = sizeof(int),
1125                 .mode           = 0644,
1126                 .proc_handler   = &proc_dointvec,
1127         },
1128         {
1129                 .ctl_name       = FS_AIO_NR,
1130                 .procname       = "aio-nr",
1131                 .data           = &aio_nr,
1132                 .maxlen         = sizeof(aio_nr),
1133                 .mode           = 0444,
1134                 .proc_handler   = &proc_doulongvec_minmax,
1135         },
1136         {
1137                 .ctl_name       = FS_AIO_MAX_NR,
1138                 .procname       = "aio-max-nr",
1139                 .data           = &aio_max_nr,
1140                 .maxlen         = sizeof(aio_max_nr),
1141                 .mode           = 0644,
1142                 .proc_handler   = &proc_doulongvec_minmax,
1143         },
1144 #ifdef CONFIG_INOTIFY_USER
1145         {
1146                 .ctl_name       = FS_INOTIFY,
1147                 .procname       = "inotify",
1148                 .mode           = 0555,
1149                 .child          = inotify_table,
1150         },
1151 #endif
1152 #endif
1153         {
1154                 .ctl_name       = KERN_SETUID_DUMPABLE,
1155                 .procname       = "suid_dumpable",
1156                 .data           = &suid_dumpable,
1157                 .maxlen         = sizeof(int),
1158                 .mode           = 0644,
1159                 .proc_handler   = &proc_dointvec,
1160         },
1161 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1162         {
1163                 .ctl_name       = CTL_UNNUMBERED,
1164                 .procname       = "binfmt_misc",
1165                 .mode           = 0555,
1166                 .child          = binfmt_misc_table,
1167         },
1168 #endif
1169 /*
1170  * NOTE: do not add new entries to this table unless you have read
1171  * Documentation/sysctl/ctl_unnumbered.txt
1172  */
1173         { .ctl_name = 0 }
1174 };
1175
1176 static ctl_table debug_table[] = {
1177         { .ctl_name = 0 }
1178 };
1179
1180 static ctl_table dev_table[] = {
1181         { .ctl_name = 0 }
1182 };
1183
1184 static DEFINE_SPINLOCK(sysctl_lock);
1185
1186 /* called under sysctl_lock */
1187 static int use_table(struct ctl_table_header *p)
1188 {
1189         if (unlikely(p->unregistering))
1190                 return 0;
1191         p->used++;
1192         return 1;
1193 }
1194
1195 /* called under sysctl_lock */
1196 static void unuse_table(struct ctl_table_header *p)
1197 {
1198         if (!--p->used)
1199                 if (unlikely(p->unregistering))
1200                         complete(p->unregistering);
1201 }
1202
1203 /* called under sysctl_lock, will reacquire if has to wait */
1204 static void start_unregistering(struct ctl_table_header *p)
1205 {
1206         /*
1207          * if p->used is 0, nobody will ever touch that entry again;
1208          * we'll eliminate all paths to it before dropping sysctl_lock
1209          */
1210         if (unlikely(p->used)) {
1211                 struct completion wait;
1212                 init_completion(&wait);
1213                 p->unregistering = &wait;
1214                 spin_unlock(&sysctl_lock);
1215                 wait_for_completion(&wait);
1216                 spin_lock(&sysctl_lock);
1217         }
1218         /*
1219          * do not remove from the list until nobody holds it; walking the
1220          * list in do_sysctl() relies on that.
1221          */
1222         list_del_init(&p->ctl_entry);
1223 }
1224
1225 void sysctl_head_finish(struct ctl_table_header *head)
1226 {
1227         if (!head)
1228                 return;
1229         spin_lock(&sysctl_lock);
1230         unuse_table(head);
1231         spin_unlock(&sysctl_lock);
1232 }
1233
1234 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1235 {
1236         struct ctl_table_header *head;
1237         struct list_head *tmp;
1238         spin_lock(&sysctl_lock);
1239         if (prev) {
1240                 tmp = &prev->ctl_entry;
1241                 unuse_table(prev);
1242                 goto next;
1243         }
1244         tmp = &root_table_header.ctl_entry;
1245         for (;;) {
1246                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1247
1248                 if (!use_table(head))
1249                         goto next;
1250                 spin_unlock(&sysctl_lock);
1251                 return head;
1252         next:
1253                 tmp = tmp->next;
1254                 if (tmp == &root_table_header.ctl_entry)
1255                         break;
1256         }
1257         spin_unlock(&sysctl_lock);
1258         return NULL;
1259 }
1260
1261 #ifdef CONFIG_SYSCTL_SYSCALL
1262 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1263                void __user *newval, size_t newlen)
1264 {
1265         struct ctl_table_header *head;
1266         int error = -ENOTDIR;
1267
1268         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1269                 return -ENOTDIR;
1270         if (oldval) {
1271                 int old_len;
1272                 if (!oldlenp || get_user(old_len, oldlenp))
1273                         return -EFAULT;
1274         }
1275
1276         for (head = sysctl_head_next(NULL); head;
1277                         head = sysctl_head_next(head)) {
1278                 error = parse_table(name, nlen, oldval, oldlenp,
1279                                         newval, newlen, head->ctl_table);
1280                 if (error != -ENOTDIR) {
1281                         sysctl_head_finish(head);
1282                         break;
1283                 }
1284         }
1285         return error;
1286 }
1287
1288 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1289 {
1290         struct __sysctl_args tmp;
1291         int error;
1292
1293         if (copy_from_user(&tmp, args, sizeof(tmp)))
1294                 return -EFAULT;
1295
1296         lock_kernel();
1297         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1298                           tmp.newval, tmp.newlen);
1299         unlock_kernel();
1300         return error;
1301 }
1302 #endif /* CONFIG_SYSCTL_SYSCALL */
1303
1304 /*
1305  * sysctl_perm does NOT grant the superuser all rights automatically, because
1306  * some sysctl variables are readonly even to root.
1307  */
1308
1309 static int test_perm(int mode, int op)
1310 {
1311         if (!current->euid)
1312                 mode >>= 6;
1313         else if (in_egroup_p(0))
1314                 mode >>= 3;
1315         if ((mode & op & 0007) == op)
1316                 return 0;
1317         return -EACCES;
1318 }
1319
1320 int sysctl_perm(ctl_table *table, int op)
1321 {
1322         int error;
1323         error = security_sysctl(table, op);
1324         if (error)
1325                 return error;
1326         return test_perm(table->mode, op);
1327 }
1328
1329 #ifdef CONFIG_SYSCTL_SYSCALL
1330 static int parse_table(int __user *name, int nlen,
1331                        void __user *oldval, size_t __user *oldlenp,
1332                        void __user *newval, size_t newlen,
1333                        ctl_table *table)
1334 {
1335         int n;
1336 repeat:
1337         if (!nlen)
1338                 return -ENOTDIR;
1339         if (get_user(n, name))
1340                 return -EFAULT;
1341         for ( ; table->ctl_name || table->procname; table++) {
1342                 if (!table->ctl_name)
1343                         continue;
1344                 if (n == table->ctl_name) {
1345                         int error;
1346                         if (table->child) {
1347                                 if (sysctl_perm(table, 001))
1348                                         return -EPERM;
1349                                 name++;
1350                                 nlen--;
1351                                 table = table->child;
1352                                 goto repeat;
1353                         }
1354                         error = do_sysctl_strategy(table, name, nlen,
1355                                                    oldval, oldlenp,
1356                                                    newval, newlen);
1357                         return error;
1358                 }
1359         }
1360         return -ENOTDIR;
1361 }
1362
1363 /* Perform the actual read/write of a sysctl table entry. */
1364 int do_sysctl_strategy (ctl_table *table,
1365                         int __user *name, int nlen,
1366                         void __user *oldval, size_t __user *oldlenp,
1367                         void __user *newval, size_t newlen)
1368 {
1369         int op = 0, rc;
1370         size_t len;
1371
1372         if (oldval)
1373                 op |= 004;
1374         if (newval)
1375                 op |= 002;
1376         if (sysctl_perm(table, op))
1377                 return -EPERM;
1378
1379         if (table->strategy) {
1380                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1381                                      newval, newlen);
1382                 if (rc < 0)
1383                         return rc;
1384                 if (rc > 0)
1385                         return 0;
1386         }
1387
1388         /* If there is no strategy routine, or if the strategy returns
1389          * zero, proceed with automatic r/w */
1390         if (table->data && table->maxlen) {
1391                 if (oldval && oldlenp) {
1392                         if (get_user(len, oldlenp))
1393                                 return -EFAULT;
1394                         if (len) {
1395                                 if (len > table->maxlen)
1396                                         len = table->maxlen;
1397                                 if(copy_to_user(oldval, table->data, len))
1398                                         return -EFAULT;
1399                                 if(put_user(len, oldlenp))
1400                                         return -EFAULT;
1401                         }
1402                 }
1403                 if (newval && newlen) {
1404                         len = newlen;
1405                         if (len > table->maxlen)
1406                                 len = table->maxlen;
1407                         if(copy_from_user(table->data, newval, len))
1408                                 return -EFAULT;
1409                 }
1410         }
1411         return 0;
1412 }
1413 #endif /* CONFIG_SYSCTL_SYSCALL */
1414
1415 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1416 {
1417         for (; table->ctl_name || table->procname; table++) {
1418                 table->parent = parent;
1419                 if (table->child)
1420                         sysctl_set_parent(table, table->child);
1421         }
1422 }
1423
1424 static __init int sysctl_init(void)
1425 {
1426         sysctl_set_parent(NULL, root_table);
1427         return 0;
1428 }
1429
1430 core_initcall(sysctl_init);
1431
1432 /**
1433  * register_sysctl_table - register a sysctl hierarchy
1434  * @table: the top-level table structure
1435  *
1436  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1437  * array. An entry with a ctl_name of 0 terminates the table.
1438  *
1439  * The members of the &ctl_table structure are used as follows:
1440  *
1441  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1442  *            must be unique within that level of sysctl
1443  *
1444  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1445  *            enter a sysctl file
1446  *
1447  * data - a pointer to data for use by proc_handler
1448  *
1449  * maxlen - the maximum size in bytes of the data
1450  *
1451  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1452  *
1453  * child - a pointer to the child sysctl table if this entry is a directory, or
1454  *         %NULL.
1455  *
1456  * proc_handler - the text handler routine (described below)
1457  *
1458  * strategy - the strategy routine (described below)
1459  *
1460  * de - for internal use by the sysctl routines
1461  *
1462  * extra1, extra2 - extra pointers usable by the proc handler routines
1463  *
1464  * Leaf nodes in the sysctl tree will be represented by a single file
1465  * under /proc; non-leaf nodes will be represented by directories.
1466  *
1467  * sysctl(2) can automatically manage read and write requests through
1468  * the sysctl table.  The data and maxlen fields of the ctl_table
1469  * struct enable minimal validation of the values being written to be
1470  * performed, and the mode field allows minimal authentication.
1471  *
1472  * More sophisticated management can be enabled by the provision of a
1473  * strategy routine with the table entry.  This will be called before
1474  * any automatic read or write of the data is performed.
1475  *
1476  * The strategy routine may return
1477  *
1478  * < 0 - Error occurred (error is passed to user process)
1479  *
1480  * 0   - OK - proceed with automatic read or write.
1481  *
1482  * > 0 - OK - read or write has been done by the strategy routine, so
1483  *       return immediately.
1484  *
1485  * There must be a proc_handler routine for any terminal nodes
1486  * mirrored under /proc/sys (non-terminals are handled by a built-in
1487  * directory handler).  Several default handlers are available to
1488  * cover common cases -
1489  *
1490  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1491  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1492  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1493  *
1494  * It is the handler's job to read the input buffer from user memory
1495  * and process it. The handler should return 0 on success.
1496  *
1497  * This routine returns %NULL on a failure to register, and a pointer
1498  * to the table header on success.
1499  */
1500 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1501 {
1502         struct ctl_table_header *tmp;
1503         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1504         if (!tmp)
1505                 return NULL;
1506         tmp->ctl_table = table;
1507         INIT_LIST_HEAD(&tmp->ctl_entry);
1508         tmp->used = 0;
1509         tmp->unregistering = NULL;
1510         sysctl_set_parent(NULL, table);
1511         spin_lock(&sysctl_lock);
1512         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1513         spin_unlock(&sysctl_lock);
1514         return tmp;
1515 }
1516
1517 /**
1518  * unregister_sysctl_table - unregister a sysctl table hierarchy
1519  * @header: the header returned from register_sysctl_table
1520  *
1521  * Unregisters the sysctl table and all children. proc entries may not
1522  * actually be removed until they are no longer used by anyone.
1523  */
1524 void unregister_sysctl_table(struct ctl_table_header * header)
1525 {
1526         might_sleep();
1527         spin_lock(&sysctl_lock);
1528         start_unregistering(header);
1529         spin_unlock(&sysctl_lock);
1530         kfree(header);
1531 }
1532
1533 #else /* !CONFIG_SYSCTL */
1534 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1535 {
1536         return NULL;
1537 }
1538
1539 void unregister_sysctl_table(struct ctl_table_header * table)
1540 {
1541 }
1542
1543 #endif /* CONFIG_SYSCTL */
1544
1545 /*
1546  * /proc/sys support
1547  */
1548
1549 #ifdef CONFIG_PROC_SYSCTL
1550
1551 static int _proc_do_string(void* data, int maxlen, int write,
1552                            struct file *filp, void __user *buffer,
1553                            size_t *lenp, loff_t *ppos)
1554 {
1555         size_t len;
1556         char __user *p;
1557         char c;
1558
1559         if (!data || !maxlen || !*lenp) {
1560                 *lenp = 0;
1561                 return 0;
1562         }
1563
1564         if (write) {
1565                 len = 0;
1566                 p = buffer;
1567                 while (len < *lenp) {
1568                         if (get_user(c, p++))
1569                                 return -EFAULT;
1570                         if (c == 0 || c == '\n')
1571                                 break;
1572                         len++;
1573                 }
1574                 if (len >= maxlen)
1575                         len = maxlen-1;
1576                 if(copy_from_user(data, buffer, len))
1577                         return -EFAULT;
1578                 ((char *) data)[len] = 0;
1579                 *ppos += *lenp;
1580         } else {
1581                 len = strlen(data);
1582                 if (len > maxlen)
1583                         len = maxlen;
1584
1585                 if (*ppos > len) {
1586                         *lenp = 0;
1587                         return 0;
1588                 }
1589
1590                 data += *ppos;
1591                 len  -= *ppos;
1592
1593                 if (len > *lenp)
1594                         len = *lenp;
1595                 if (len)
1596                         if(copy_to_user(buffer, data, len))
1597                                 return -EFAULT;
1598                 if (len < *lenp) {
1599                         if(put_user('\n', ((char __user *) buffer) + len))
1600                                 return -EFAULT;
1601                         len++;
1602                 }
1603                 *lenp = len;
1604                 *ppos += len;
1605         }
1606         return 0;
1607 }
1608
1609 /**
1610  * proc_dostring - read a string sysctl
1611  * @table: the sysctl table
1612  * @write: %TRUE if this is a write to the sysctl file
1613  * @filp: the file structure
1614  * @buffer: the user buffer
1615  * @lenp: the size of the user buffer
1616  * @ppos: file position
1617  *
1618  * Reads/writes a string from/to the user buffer. If the kernel
1619  * buffer provided is not large enough to hold the string, the
1620  * string is truncated. The copied string is %NULL-terminated.
1621  * If the string is being read by the user process, it is copied
1622  * and a newline '\n' is added. It is truncated if the buffer is
1623  * not large enough.
1624  *
1625  * Returns 0 on success.
1626  */
1627 int proc_dostring(ctl_table *table, int write, struct file *filp,
1628                   void __user *buffer, size_t *lenp, loff_t *ppos)
1629 {
1630         return _proc_do_string(table->data, table->maxlen, write, filp,
1631                                buffer, lenp, ppos);
1632 }
1633
1634
1635 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1636                                  int *valp,
1637                                  int write, void *data)
1638 {
1639         if (write) {
1640                 *valp = *negp ? -*lvalp : *lvalp;
1641         } else {
1642                 int val = *valp;
1643                 if (val < 0) {
1644                         *negp = -1;
1645                         *lvalp = (unsigned long)-val;
1646                 } else {
1647                         *negp = 0;
1648                         *lvalp = (unsigned long)val;
1649                 }
1650         }
1651         return 0;
1652 }
1653
1654 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1655                   int write, struct file *filp, void __user *buffer,
1656                   size_t *lenp, loff_t *ppos,
1657                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1658                               int write, void *data),
1659                   void *data)
1660 {
1661 #define TMPBUFLEN 21
1662         int *i, vleft, first=1, neg, val;
1663         unsigned long lval;
1664         size_t left, len;
1665
1666         char buf[TMPBUFLEN], *p;
1667         char __user *s = buffer;
1668
1669         if (!tbl_data || !table->maxlen || !*lenp ||
1670             (*ppos && !write)) {
1671                 *lenp = 0;
1672                 return 0;
1673         }
1674
1675         i = (int *) tbl_data;
1676         vleft = table->maxlen / sizeof(*i);
1677         left = *lenp;
1678
1679         if (!conv)
1680                 conv = do_proc_dointvec_conv;
1681
1682         for (; left && vleft--; i++, first=0) {
1683                 if (write) {
1684                         while (left) {
1685                                 char c;
1686                                 if (get_user(c, s))
1687                                         return -EFAULT;
1688                                 if (!isspace(c))
1689                                         break;
1690                                 left--;
1691                                 s++;
1692                         }
1693                         if (!left)
1694                                 break;
1695                         neg = 0;
1696                         len = left;
1697                         if (len > sizeof(buf) - 1)
1698                                 len = sizeof(buf) - 1;
1699                         if (copy_from_user(buf, s, len))
1700                                 return -EFAULT;
1701                         buf[len] = 0;
1702                         p = buf;
1703                         if (*p == '-' && left > 1) {
1704                                 neg = 1;
1705                                 p++;
1706                         }
1707                         if (*p < '0' || *p > '9')
1708                                 break;
1709
1710                         lval = simple_strtoul(p, &p, 0);
1711
1712                         len = p-buf;
1713                         if ((len < left) && *p && !isspace(*p))
1714                                 break;
1715                         if (neg)
1716                                 val = -val;
1717                         s += len;
1718                         left -= len;
1719
1720                         if (conv(&neg, &lval, i, 1, data))
1721                                 break;
1722                 } else {
1723                         p = buf;
1724                         if (!first)
1725                                 *p++ = '\t';
1726
1727                         if (conv(&neg, &lval, i, 0, data))
1728                                 break;
1729
1730                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1731                         len = strlen(buf);
1732                         if (len > left)
1733                                 len = left;
1734                         if(copy_to_user(s, buf, len))
1735                                 return -EFAULT;
1736                         left -= len;
1737                         s += len;
1738                 }
1739         }
1740
1741         if (!write && !first && left) {
1742                 if(put_user('\n', s))
1743                         return -EFAULT;
1744                 left--, s++;
1745         }
1746         if (write) {
1747                 while (left) {
1748                         char c;
1749                         if (get_user(c, s++))
1750                                 return -EFAULT;
1751                         if (!isspace(c))
1752                                 break;
1753                         left--;
1754                 }
1755         }
1756         if (write && first)
1757                 return -EINVAL;
1758         *lenp -= left;
1759         *ppos += *lenp;
1760         return 0;
1761 #undef TMPBUFLEN
1762 }
1763
1764 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1765                   void __user *buffer, size_t *lenp, loff_t *ppos,
1766                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1767                               int write, void *data),
1768                   void *data)
1769 {
1770         return __do_proc_dointvec(table->data, table, write, filp,
1771                         buffer, lenp, ppos, conv, data);
1772 }
1773
1774 /**
1775  * proc_dointvec - read a vector of integers
1776  * @table: the sysctl table
1777  * @write: %TRUE if this is a write to the sysctl file
1778  * @filp: the file structure
1779  * @buffer: the user buffer
1780  * @lenp: the size of the user buffer
1781  * @ppos: file position
1782  *
1783  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1784  * values from/to the user buffer, treated as an ASCII string.
1785  *
1786  * Returns 0 on success.
1787  */
1788 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1789                      void __user *buffer, size_t *lenp, loff_t *ppos)
1790 {
1791     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1792                             NULL,NULL);
1793 }
1794
1795 #define OP_SET  0
1796 #define OP_AND  1
1797 #define OP_OR   2
1798
1799 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1800                                       int *valp,
1801                                       int write, void *data)
1802 {
1803         int op = *(int *)data;
1804         if (write) {
1805                 int val = *negp ? -*lvalp : *lvalp;
1806                 switch(op) {
1807                 case OP_SET:    *valp = val; break;
1808                 case OP_AND:    *valp &= val; break;
1809                 case OP_OR:     *valp |= val; break;
1810                 }
1811         } else {
1812                 int val = *valp;
1813                 if (val < 0) {
1814                         *negp = -1;
1815                         *lvalp = (unsigned long)-val;
1816                 } else {
1817                         *negp = 0;
1818                         *lvalp = (unsigned long)val;
1819                 }
1820         }
1821         return 0;
1822 }
1823
1824 /*
1825  *      init may raise the set.
1826  */
1827
1828 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1829                         void __user *buffer, size_t *lenp, loff_t *ppos)
1830 {
1831         int op;
1832
1833         if (write && !capable(CAP_SYS_MODULE)) {
1834                 return -EPERM;
1835         }
1836
1837         op = is_init(current) ? OP_SET : OP_AND;
1838         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1839                                 do_proc_dointvec_bset_conv,&op);
1840 }
1841
1842 /*
1843  *      Taint values can only be increased
1844  */
1845 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1846                                void __user *buffer, size_t *lenp, loff_t *ppos)
1847 {
1848         int op;
1849
1850         if (write && !capable(CAP_SYS_ADMIN))
1851                 return -EPERM;
1852
1853         op = OP_OR;
1854         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1855                                 do_proc_dointvec_bset_conv,&op);
1856 }
1857
1858 struct do_proc_dointvec_minmax_conv_param {
1859         int *min;
1860         int *max;
1861 };
1862
1863 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1864                                         int *valp,
1865                                         int write, void *data)
1866 {
1867         struct do_proc_dointvec_minmax_conv_param *param = data;
1868         if (write) {
1869                 int val = *negp ? -*lvalp : *lvalp;
1870                 if ((param->min && *param->min > val) ||
1871                     (param->max && *param->max < val))
1872                         return -EINVAL;
1873                 *valp = val;
1874         } else {
1875                 int val = *valp;
1876                 if (val < 0) {
1877                         *negp = -1;
1878                         *lvalp = (unsigned long)-val;
1879                 } else {
1880                         *negp = 0;
1881                         *lvalp = (unsigned long)val;
1882                 }
1883         }
1884         return 0;
1885 }
1886
1887 /**
1888  * proc_dointvec_minmax - read a vector of integers with min/max values
1889  * @table: the sysctl table
1890  * @write: %TRUE if this is a write to the sysctl file
1891  * @filp: the file structure
1892  * @buffer: the user buffer
1893  * @lenp: the size of the user buffer
1894  * @ppos: file position
1895  *
1896  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1897  * values from/to the user buffer, treated as an ASCII string.
1898  *
1899  * This routine will ensure the values are within the range specified by
1900  * table->extra1 (min) and table->extra2 (max).
1901  *
1902  * Returns 0 on success.
1903  */
1904 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1905                   void __user *buffer, size_t *lenp, loff_t *ppos)
1906 {
1907         struct do_proc_dointvec_minmax_conv_param param = {
1908                 .min = (int *) table->extra1,
1909                 .max = (int *) table->extra2,
1910         };
1911         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1912                                 do_proc_dointvec_minmax_conv, &param);
1913 }
1914
1915 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1916                                      struct file *filp,
1917                                      void __user *buffer,
1918                                      size_t *lenp, loff_t *ppos,
1919                                      unsigned long convmul,
1920                                      unsigned long convdiv)
1921 {
1922 #define TMPBUFLEN 21
1923         unsigned long *i, *min, *max, val;
1924         int vleft, first=1, neg;
1925         size_t len, left;
1926         char buf[TMPBUFLEN], *p;
1927         char __user *s = buffer;
1928
1929         if (!data || !table->maxlen || !*lenp ||
1930             (*ppos && !write)) {
1931                 *lenp = 0;
1932                 return 0;
1933         }
1934
1935         i = (unsigned long *) data;
1936         min = (unsigned long *) table->extra1;
1937         max = (unsigned long *) table->extra2;
1938         vleft = table->maxlen / sizeof(unsigned long);
1939         left = *lenp;
1940
1941         for (; left && vleft--; i++, min++, max++, first=0) {
1942                 if (write) {
1943                         while (left) {
1944                                 char c;
1945                                 if (get_user(c, s))
1946                                         return -EFAULT;
1947                                 if (!isspace(c))
1948                                         break;
1949                                 left--;
1950                                 s++;
1951                         }
1952                         if (!left)
1953                                 break;
1954                         neg = 0;
1955                         len = left;
1956                         if (len > TMPBUFLEN-1)
1957                                 len = TMPBUFLEN-1;
1958                         if (copy_from_user(buf, s, len))
1959                                 return -EFAULT;
1960                         buf[len] = 0;
1961                         p = buf;
1962                         if (*p == '-' && left > 1) {
1963                                 neg = 1;
1964                                 p++;
1965                         }
1966                         if (*p < '0' || *p > '9')
1967                                 break;
1968                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1969                         len = p-buf;
1970                         if ((len < left) && *p && !isspace(*p))
1971                                 break;
1972                         if (neg)
1973                                 val = -val;
1974                         s += len;
1975                         left -= len;
1976
1977                         if(neg)
1978                                 continue;
1979                         if ((min && val < *min) || (max && val > *max))
1980                                 continue;
1981                         *i = val;
1982                 } else {
1983                         p = buf;
1984                         if (!first)
1985                                 *p++ = '\t';
1986                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1987                         len = strlen(buf);
1988                         if (len > left)
1989                                 len = left;
1990                         if(copy_to_user(s, buf, len))
1991                                 return -EFAULT;
1992                         left -= len;
1993                         s += len;
1994                 }
1995         }
1996
1997         if (!write && !first && left) {
1998                 if(put_user('\n', s))
1999                         return -EFAULT;
2000                 left--, s++;
2001         }
2002         if (write) {
2003                 while (left) {
2004                         char c;
2005                         if (get_user(c, s++))
2006                                 return -EFAULT;
2007                         if (!isspace(c))
2008                                 break;
2009                         left--;
2010                 }
2011         }
2012         if (write && first)
2013                 return -EINVAL;
2014         *lenp -= left;
2015         *ppos += *lenp;
2016         return 0;
2017 #undef TMPBUFLEN
2018 }
2019
2020 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2021                                      struct file *filp,
2022                                      void __user *buffer,
2023                                      size_t *lenp, loff_t *ppos,
2024                                      unsigned long convmul,
2025                                      unsigned long convdiv)
2026 {
2027         return __do_proc_doulongvec_minmax(table->data, table, write,
2028                         filp, buffer, lenp, ppos, convmul, convdiv);
2029 }
2030
2031 /**
2032  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2033  * @table: the sysctl table
2034  * @write: %TRUE if this is a write to the sysctl file
2035  * @filp: the file structure
2036  * @buffer: the user buffer
2037  * @lenp: the size of the user buffer
2038  * @ppos: file position
2039  *
2040  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2041  * values from/to the user buffer, treated as an ASCII string.
2042  *
2043  * This routine will ensure the values are within the range specified by
2044  * table->extra1 (min) and table->extra2 (max).
2045  *
2046  * Returns 0 on success.
2047  */
2048 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2049                            void __user *buffer, size_t *lenp, loff_t *ppos)
2050 {
2051     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2052 }
2053
2054 /**
2055  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2056  * @table: the sysctl table
2057  * @write: %TRUE if this is a write to the sysctl file
2058  * @filp: the file structure
2059  * @buffer: the user buffer
2060  * @lenp: the size of the user buffer
2061  * @ppos: file position
2062  *
2063  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2064  * values from/to the user buffer, treated as an ASCII string. The values
2065  * are treated as milliseconds, and converted to jiffies when they are stored.
2066  *
2067  * This routine will ensure the values are within the range specified by
2068  * table->extra1 (min) and table->extra2 (max).
2069  *
2070  * Returns 0 on success.
2071  */
2072 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2073                                       struct file *filp,
2074                                       void __user *buffer,
2075                                       size_t *lenp, loff_t *ppos)
2076 {
2077     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2078                                      lenp, ppos, HZ, 1000l);
2079 }
2080
2081
2082 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2083                                          int *valp,
2084                                          int write, void *data)
2085 {
2086         if (write) {
2087                 if (*lvalp > LONG_MAX / HZ)
2088                         return 1;
2089                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2090         } else {
2091                 int val = *valp;
2092                 unsigned long lval;
2093                 if (val < 0) {
2094                         *negp = -1;
2095                         lval = (unsigned long)-val;
2096                 } else {
2097                         *negp = 0;
2098                         lval = (unsigned long)val;
2099                 }
2100                 *lvalp = lval / HZ;
2101         }
2102         return 0;
2103 }
2104
2105 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2106                                                 int *valp,
2107                                                 int write, void *data)
2108 {
2109         if (write) {
2110                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2111                         return 1;
2112                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2113         } else {
2114                 int val = *valp;
2115                 unsigned long lval;
2116                 if (val < 0) {
2117                         *negp = -1;
2118                         lval = (unsigned long)-val;
2119                 } else {
2120                         *negp = 0;
2121                         lval = (unsigned long)val;
2122                 }
2123                 *lvalp = jiffies_to_clock_t(lval);
2124         }
2125         return 0;
2126 }
2127
2128 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2129                                             int *valp,
2130                                             int write, void *data)
2131 {
2132         if (write) {
2133                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2134         } else {
2135                 int val = *valp;
2136                 unsigned long lval;
2137                 if (val < 0) {
2138                         *negp = -1;
2139                         lval = (unsigned long)-val;
2140                 } else {
2141                         *negp = 0;
2142                         lval = (unsigned long)val;
2143                 }
2144                 *lvalp = jiffies_to_msecs(lval);
2145         }
2146         return 0;
2147 }
2148
2149 /**
2150  * proc_dointvec_jiffies - read a vector of integers as seconds
2151  * @table: the sysctl table
2152  * @write: %TRUE if this is a write to the sysctl file
2153  * @filp: the file structure
2154  * @buffer: the user buffer
2155  * @lenp: the size of the user buffer
2156  * @ppos: file position
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 seconds, and are converted into
2161  * jiffies.
2162  *
2163  * Returns 0 on success.
2164  */
2165 int proc_dointvec_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_jiffies_conv,NULL);
2170 }
2171
2172 /**
2173  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2174  * @table: the sysctl table
2175  * @write: %TRUE if this is a write to the sysctl file
2176  * @filp: the file structure
2177  * @buffer: the user buffer
2178  * @lenp: the size of the user buffer
2179  * @ppos: pointer to the file position
2180  *
2181  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2182  * values from/to the user buffer, treated as an ASCII string.
2183  * The values read are assumed to be in 1/USER_HZ seconds, and
2184  * are converted into jiffies.
2185  *
2186  * Returns 0 on success.
2187  */
2188 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2189                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2190 {
2191     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2192                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2193 }
2194
2195 /**
2196  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2197  * @table: the sysctl table
2198  * @write: %TRUE if this is a write to the sysctl file
2199  * @filp: the file structure
2200  * @buffer: the user buffer
2201  * @lenp: the size of the user buffer
2202  * @ppos: file position
2203  * @ppos: the current position in the file
2204  *
2205  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2206  * values from/to the user buffer, treated as an ASCII string.
2207  * The values read are assumed to be in 1/1000 seconds, and
2208  * are converted into jiffies.
2209  *
2210  * Returns 0 on success.
2211  */
2212 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2213                              void __user *buffer, size_t *lenp, loff_t *ppos)
2214 {
2215         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2216                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2217 }
2218
2219 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2220                            void __user *buffer, size_t *lenp, loff_t *ppos)
2221 {
2222         struct pid *new_pid;
2223         pid_t tmp;
2224         int r;
2225
2226         tmp = pid_nr(cad_pid);
2227
2228         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2229                                lenp, ppos, NULL, NULL);
2230         if (r || !write)
2231                 return r;
2232
2233         new_pid = find_get_pid(tmp);
2234         if (!new_pid)
2235                 return -ESRCH;
2236
2237         put_pid(xchg(&cad_pid, new_pid));
2238         return 0;
2239 }
2240
2241 #else /* CONFIG_PROC_FS */
2242
2243 int proc_dostring(ctl_table *table, int write, struct file *filp,
2244                   void __user *buffer, size_t *lenp, loff_t *ppos)
2245 {
2246         return -ENOSYS;
2247 }
2248
2249 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2250                   void __user *buffer, size_t *lenp, loff_t *ppos)
2251 {
2252         return -ENOSYS;
2253 }
2254
2255 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2256                         void __user *buffer, size_t *lenp, loff_t *ppos)
2257 {
2258         return -ENOSYS;
2259 }
2260
2261 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2262                     void __user *buffer, size_t *lenp, loff_t *ppos)
2263 {
2264         return -ENOSYS;
2265 }
2266
2267 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2268                     void __user *buffer, size_t *lenp, loff_t *ppos)
2269 {
2270         return -ENOSYS;
2271 }
2272
2273 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2274                     void __user *buffer, size_t *lenp, loff_t *ppos)
2275 {
2276         return -ENOSYS;
2277 }
2278
2279 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2280                              void __user *buffer, size_t *lenp, loff_t *ppos)
2281 {
2282         return -ENOSYS;
2283 }
2284
2285 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2286                     void __user *buffer, size_t *lenp, loff_t *ppos)
2287 {
2288         return -ENOSYS;
2289 }
2290
2291 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2292                                       struct file *filp,
2293                                       void __user *buffer,
2294                                       size_t *lenp, loff_t *ppos)
2295 {
2296     return -ENOSYS;
2297 }
2298
2299
2300 #endif /* CONFIG_PROC_FS */
2301
2302
2303 #ifdef CONFIG_SYSCTL_SYSCALL
2304 /*
2305  * General sysctl support routines
2306  */
2307
2308 /* The generic string strategy routine: */
2309 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2310                   void __user *oldval, size_t __user *oldlenp,
2311                   void __user *newval, size_t newlen)
2312 {
2313         if (!table->data || !table->maxlen)
2314                 return -ENOTDIR;
2315
2316         if (oldval && oldlenp) {
2317                 size_t bufsize;
2318                 if (get_user(bufsize, oldlenp))
2319                         return -EFAULT;
2320                 if (bufsize) {
2321                         size_t len = strlen(table->data), copied;
2322
2323                         /* This shouldn't trigger for a well-formed sysctl */
2324                         if (len > table->maxlen)
2325                                 len = table->maxlen;
2326
2327                         /* Copy up to a max of bufsize-1 bytes of the string */
2328                         copied = (len >= bufsize) ? bufsize - 1 : len;
2329
2330                         if (copy_to_user(oldval, table->data, copied) ||
2331                             put_user(0, (char __user *)(oldval + copied)))
2332                                 return -EFAULT;
2333                         if (put_user(len, oldlenp))
2334                                 return -EFAULT;
2335                 }
2336         }
2337         if (newval && newlen) {
2338                 size_t len = newlen;
2339                 if (len > table->maxlen)
2340                         len = table->maxlen;
2341                 if(copy_from_user(table->data, newval, len))
2342                         return -EFAULT;
2343                 if (len == table->maxlen)
2344                         len--;
2345                 ((char *) table->data)[len] = 0;
2346         }
2347         return 1;
2348 }
2349
2350 /*
2351  * This function makes sure that all of the integers in the vector
2352  * are between the minimum and maximum values given in the arrays
2353  * table->extra1 and table->extra2, respectively.
2354  */
2355 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2356                 void __user *oldval, size_t __user *oldlenp,
2357                 void __user *newval, size_t newlen)
2358 {
2359
2360         if (newval && newlen) {
2361                 int __user *vec = (int __user *) newval;
2362                 int *min = (int *) table->extra1;
2363                 int *max = (int *) table->extra2;
2364                 size_t length;
2365                 int i;
2366
2367                 if (newlen % sizeof(int) != 0)
2368                         return -EINVAL;
2369
2370                 if (!table->extra1 && !table->extra2)
2371                         return 0;
2372
2373                 if (newlen > table->maxlen)
2374                         newlen = table->maxlen;
2375                 length = newlen / sizeof(int);
2376
2377                 for (i = 0; i < length; i++) {
2378                         int value;
2379                         if (get_user(value, vec + i))
2380                                 return -EFAULT;
2381                         if (min && value < min[i])
2382                                 return -EINVAL;
2383                         if (max && value > max[i])
2384                                 return -EINVAL;
2385                 }
2386         }
2387         return 0;
2388 }
2389
2390 /* Strategy function to convert jiffies to seconds */
2391 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2392                 void __user *oldval, size_t __user *oldlenp,
2393                 void __user *newval, size_t newlen)
2394 {
2395         if (oldval && oldlenp) {
2396                 size_t olen;
2397
2398                 if (get_user(olen, oldlenp))
2399                         return -EFAULT;
2400                 if (olen) {
2401                         int val;
2402
2403                         if (olen < sizeof(int))
2404                                 return -EINVAL;
2405
2406                         val = *(int *)(table->data) / HZ;
2407                         if (put_user(val, (int __user *)oldval))
2408                                 return -EFAULT;
2409                         if (put_user(sizeof(int), oldlenp))
2410                                 return -EFAULT;
2411                 }
2412         }
2413         if (newval && newlen) {
2414                 int new;
2415                 if (newlen != sizeof(int))
2416                         return -EINVAL;
2417                 if (get_user(new, (int __user *)newval))
2418                         return -EFAULT;
2419                 *(int *)(table->data) = new*HZ;
2420         }
2421         return 1;
2422 }
2423
2424 /* Strategy function to convert jiffies to seconds */
2425 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2426                 void __user *oldval, size_t __user *oldlenp,
2427                 void __user *newval, size_t newlen)
2428 {
2429         if (oldval && oldlenp) {
2430                 size_t olen;
2431
2432                 if (get_user(olen, oldlenp))
2433                         return -EFAULT;
2434                 if (olen) {
2435                         int val;
2436
2437                         if (olen < sizeof(int))
2438                                 return -EINVAL;
2439
2440                         val = jiffies_to_msecs(*(int *)(table->data));
2441                         if (put_user(val, (int __user *)oldval))
2442                                 return -EFAULT;
2443                         if (put_user(sizeof(int), oldlenp))
2444                                 return -EFAULT;
2445                 }
2446         }
2447         if (newval && newlen) {
2448                 int new;
2449                 if (newlen != sizeof(int))
2450                         return -EINVAL;
2451                 if (get_user(new, (int __user *)newval))
2452                         return -EFAULT;
2453                 *(int *)(table->data) = msecs_to_jiffies(new);
2454         }
2455         return 1;
2456 }
2457
2458
2459
2460 #else /* CONFIG_SYSCTL_SYSCALL */
2461
2462
2463 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2464 {
2465         static int msg_count;
2466         struct __sysctl_args tmp;
2467         int name[CTL_MAXNAME];
2468         int i;
2469
2470         /* Read in the sysctl name for better debug message logging */
2471         if (copy_from_user(&tmp, args, sizeof(tmp)))
2472                 return -EFAULT;
2473         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2474                 return -ENOTDIR;
2475         for (i = 0; i < tmp.nlen; i++)
2476                 if (get_user(name[i], tmp.name + i))
2477                         return -EFAULT;
2478
2479         /* Ignore accesses to kernel.version */
2480         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2481                 goto out;
2482
2483         if (msg_count < 5) {
2484                 msg_count++;
2485                 printk(KERN_INFO
2486                         "warning: process `%s' used the removed sysctl "
2487                         "system call with ", current->comm);
2488                 for (i = 0; i < tmp.nlen; i++)
2489                         printk("%d.", name[i]);
2490                 printk("\n");
2491         }
2492 out:
2493         return -ENOSYS;
2494 }
2495
2496 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2497                   void __user *oldval, size_t __user *oldlenp,
2498                   void __user *newval, size_t newlen)
2499 {
2500         return -ENOSYS;
2501 }
2502
2503 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2504                 void __user *oldval, size_t __user *oldlenp,
2505                 void __user *newval, size_t newlen)
2506 {
2507         return -ENOSYS;
2508 }
2509
2510 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2511                 void __user *oldval, size_t __user *oldlenp,
2512                 void __user *newval, size_t newlen)
2513 {
2514         return -ENOSYS;
2515 }
2516
2517 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2518                 void __user *oldval, size_t __user *oldlenp,
2519                 void __user *newval, size_t newlen)
2520 {
2521         return -ENOSYS;
2522 }
2523
2524 #endif /* CONFIG_SYSCTL_SYSCALL */
2525
2526 /*
2527  * No sense putting this after each symbol definition, twice,
2528  * exception granted :-)
2529  */
2530 EXPORT_SYMBOL(proc_dointvec);
2531 EXPORT_SYMBOL(proc_dointvec_jiffies);
2532 EXPORT_SYMBOL(proc_dointvec_minmax);
2533 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2534 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2535 EXPORT_SYMBOL(proc_dostring);
2536 EXPORT_SYMBOL(proc_doulongvec_minmax);
2537 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2538 EXPORT_SYMBOL(register_sysctl_table);
2539 EXPORT_SYMBOL(sysctl_intvec);
2540 EXPORT_SYMBOL(sysctl_jiffies);
2541 EXPORT_SYMBOL(sysctl_ms_jiffies);
2542 EXPORT_SYMBOL(sysctl_string);
2543 EXPORT_SYMBOL(unregister_sysctl_table);