kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/capability.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/capability.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/hugetlb.h>
  40 #include <linux/security.h>
  41 #include <linux/initrd.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/nfs_fs.h>
  47 #include <linux/acpi.h>
  48
  49 #include <asm/uaccess.h>
  50 #include <asm/processor.h>
  51
  52 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
  53                      void __user *buffer, size_t *lenp, loff_t *ppos);
  54
  55 #ifdef CONFIG_X86
  56 #include <asm/nmi.h>
  57 #include <asm/stacktrace.h>
  58 #endif
  59
  60 #if defined(CONFIG_SYSCTL)
  61
  62 /* External variables not in a header file. */
  63 extern int C_A_D;
  64 extern int sysctl_overcommit_memory;
  65 extern int sysctl_overcommit_ratio;
  66 extern int sysctl_panic_on_oom;
  67 extern int max_threads;
  68 extern int core_uses_pid;
  69 extern int suid_dumpable;
  70 extern char core_pattern[];
  71 extern int pid_max;
  72 extern int min_free_kbytes;
  73 extern int printk_ratelimit_jiffies;
  74 extern int printk_ratelimit_burst;
  75 extern int pid_max_min, pid_max_max;
  76 extern int sysctl_drop_caches;
  77 extern int percpu_pagelist_fraction;
  78 extern int compat_log;
  79 extern int maps_protect;
  80 extern int sysctl_stat_interval;
  81
  82 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  83 static int maxolduid = 65535;
  84 static int minolduid;
  85 static int min_percpu_pagelist_fract = 8;
  86
  87 static int ngroups_max = NGROUPS_MAX;
  88
  89 #ifdef CONFIG_KMOD
  90 extern char modprobe_path[];
  91 #endif
  92 #ifdef CONFIG_CHR_DEV_SG
  93 extern int sg_big_buff;
  94 #endif
  95
  96 #ifdef __sparc__
  97 extern char reboot_command [];
  98 extern int stop_a_enabled;
  99 extern int scons_pwroff;
 100 #endif
 101
 102 #ifdef __hppa__
 103 extern int pwrsw_enabled;
 104 extern int unaligned_enabled;
 105 #endif
 106
 107 #ifdef CONFIG_S390
 108 #ifdef CONFIG_MATHEMU
 109 extern int sysctl_ieee_emulation_warnings;
 110 #endif
 111 extern int sysctl_userprocess_debug;
 112 extern int spin_retry;
 113 #endif
 114
 115 extern int sysctl_hz_timer;
 116
 117 #ifdef CONFIG_BSD_PROCESS_ACCT
 118 extern int acct_parm[];
 119 #endif
 120
 121 #ifdef CONFIG_IA64
 122 extern int no_unaligned_warning;
 123 #endif
 124
 125 #ifdef CONFIG_RT_MUTEXES
 126 extern int max_lock_depth;
 127 #endif
 128
 129 #ifdef CONFIG_SYSCTL_SYSCALL
 130 static int parse_table(int __user *, int, void __user *, size_t __user *,
 131                 void __user *, size_t, ctl_table *);
 132 #endif
 133
 134
 135 #ifdef CONFIG_PROC_SYSCTL
 136 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 137                   void __user *buffer, size_t *lenp, loff_t *ppos);
 138 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 139                                void __user *buffer, size_t *lenp, loff_t *ppos);
 140 #endif
 141
 142 static ctl_table root_table[];
 143 static struct ctl_table_header root_table_header =
 144         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 145
 146 static ctl_table kern_table[];
 147 static ctl_table vm_table[];
 148 static ctl_table fs_table[];
 149 static ctl_table debug_table[];
 150 static ctl_table dev_table[];
 151 extern ctl_table random_table[];
 152 #ifdef CONFIG_UNIX98_PTYS
 153 extern ctl_table pty_table[];
 154 #endif
 155 #ifdef CONFIG_INOTIFY_USER
 156 extern ctl_table inotify_table[];
 157 #endif
 158
 159 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 160 int sysctl_legacy_va_layout;
 161 #endif
 162
 163
 164 /* The default sysctl tables: */
 165
 166 static ctl_table root_table[] = {
 167         {
 168                 .ctl_name       = CTL_KERN,
 169                 .procname       = "kernel",
 170                 .mode           = 0555,
 171                 .child          = kern_table,
 172         },
 173         {
 174                 .ctl_name       = CTL_VM,
 175                 .procname       = "vm",
 176                 .mode           = 0555,
 177                 .child          = vm_table,
 178         },
 179 #ifdef CONFIG_NET
 180         {
 181                 .ctl_name       = CTL_NET,
 182                 .procname       = "net",
 183                 .mode           = 0555,
 184                 .child          = net_table,
 185         },
 186 #endif
 187         {
 188                 .ctl_name       = CTL_FS,
 189                 .procname       = "fs",
 190                 .mode           = 0555,
 191                 .child          = fs_table,
 192         },
 193         {
 194                 .ctl_name       = CTL_DEBUG,
 195                 .procname       = "debug",
 196                 .mode           = 0555,
 197                 .child          = debug_table,
 198         },
 199         {
 200                 .ctl_name       = CTL_DEV,
 201                 .procname       = "dev",
 202                 .mode           = 0555,
 203                 .child          = dev_table,
 204         },
 205
 206         { .ctl_name = 0 }
 207 };
 208
 209 #ifdef CONFIG_SCHED_DEBUG
 210 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 211 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 212 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 213 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 214 #endif
 215
 216 static ctl_table kern_table[] = {
 217 #ifdef CONFIG_SCHED_DEBUG
 218         {
 219                 .ctl_name       = CTL_UNNUMBERED,
 220                 .procname       = "sched_granularity_ns",
 221                 .data           = &sysctl_sched_granularity,
 222                 .maxlen         = sizeof(unsigned int),
 223                 .mode           = 0644,
 224                 .proc_handler   = &proc_dointvec_minmax,
 225                 .strategy       = &sysctl_intvec,
 226                 .extra1         = &min_sched_granularity_ns,
 227                 .extra2         = &max_sched_granularity_ns,
 228         },
 229         {
 230                 .ctl_name       = CTL_UNNUMBERED,
 231                 .procname       = "sched_wakeup_granularity_ns",
 232                 .data           = &sysctl_sched_wakeup_granularity,
 233                 .maxlen         = sizeof(unsigned int),
 234                 .mode           = 0644,
 235                 .proc_handler   = &proc_dointvec_minmax,
 236                 .strategy       = &sysctl_intvec,
 237                 .extra1         = &min_wakeup_granularity_ns,
 238                 .extra2         = &max_wakeup_granularity_ns,
 239         },
 240         {
 241                 .ctl_name       = CTL_UNNUMBERED,
 242                 .procname       = "sched_batch_wakeup_granularity_ns",
 243                 .data           = &sysctl_sched_batch_wakeup_granularity,
 244                 .maxlen         = sizeof(unsigned int),
 245                 .mode           = 0644,
 246                 .proc_handler   = &proc_dointvec_minmax,
 247                 .strategy       = &sysctl_intvec,
 248                 .extra1         = &min_wakeup_granularity_ns,
 249                 .extra2         = &max_wakeup_granularity_ns,
 250         },
 251         {
 252                 .ctl_name       = CTL_UNNUMBERED,
 253                 .procname       = "sched_stat_granularity_ns",
 254                 .data           = &sysctl_sched_stat_granularity,
 255                 .maxlen         = sizeof(unsigned int),
 256                 .mode           = 0644,
 257                 .proc_handler   = &proc_dointvec_minmax,
 258                 .strategy       = &sysctl_intvec,
 259                 .extra1         = &min_wakeup_granularity_ns,
 260                 .extra2         = &max_wakeup_granularity_ns,
 261         },
 262         {
 263                 .ctl_name       = CTL_UNNUMBERED,
 264                 .procname       = "sched_runtime_limit_ns",
 265                 .data           = &sysctl_sched_runtime_limit,
 266                 .maxlen         = sizeof(unsigned int),
 267                 .mode           = 0644,
 268                 .proc_handler   = &proc_dointvec_minmax,
 269                 .strategy       = &sysctl_intvec,
 270                 .extra1         = &min_sched_granularity_ns,
 271                 .extra2         = &max_sched_granularity_ns,
 272         },
 273         {
 274                 .ctl_name       = CTL_UNNUMBERED,
 275                 .procname       = "sched_child_runs_first",
 276                 .data           = &sysctl_sched_child_runs_first,
 277                 .maxlen         = sizeof(unsigned int),
 278                 .mode           = 0644,
 279                 .proc_handler   = &proc_dointvec,
 280         },
 281         {
 282                 .ctl_name       = CTL_UNNUMBERED,
 283                 .procname       = "sched_features",
 284                 .data           = &sysctl_sched_features,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289 #endif
 290         {
 291                 .ctl_name       = KERN_PANIC,
 292                 .procname       = "panic",
 293                 .data           = &panic_timeout,
 294                 .maxlen         = sizeof(int),
 295                 .mode           = 0644,
 296                 .proc_handler   = &proc_dointvec,
 297         },
 298         {
 299                 .ctl_name       = KERN_CORE_USES_PID,
 300                 .procname       = "core_uses_pid",
 301                 .data           = &core_uses_pid,
 302                 .maxlen         = sizeof(int),
 303                 .mode           = 0644,
 304                 .proc_handler   = &proc_dointvec,
 305         },
 306         {
 307                 .ctl_name       = KERN_CORE_PATTERN,
 308                 .procname       = "core_pattern",
 309                 .data           = core_pattern,
 310                 .maxlen         = CORENAME_MAX_SIZE,
 311                 .mode           = 0644,
 312                 .proc_handler   = &proc_dostring,
 313                 .strategy       = &sysctl_string,
 314         },
 315 #ifdef CONFIG_PROC_SYSCTL
 316         {
 317                 .ctl_name       = KERN_TAINTED,
 318                 .procname       = "tainted",
 319                 .data           = &tainted,
 320                 .maxlen         = sizeof(int),
 321                 .mode           = 0644,
 322                 .proc_handler   = &proc_dointvec_taint,
 323         },
 324 #endif
 325         {
 326                 .ctl_name       = KERN_CAP_BSET,
 327                 .procname       = "cap-bound",
 328                 .data           = &cap_bset,
 329                 .maxlen         = sizeof(kernel_cap_t),
 330                 .mode           = 0600,
 331                 .proc_handler   = &proc_dointvec_bset,
 332         },
 333 #ifdef CONFIG_BLK_DEV_INITRD
 334         {
 335                 .ctl_name       = KERN_REALROOTDEV,
 336                 .procname       = "real-root-dev",
 337                 .data           = &real_root_dev,
 338                 .maxlen         = sizeof(int),
 339                 .mode           = 0644,
 340                 .proc_handler   = &proc_dointvec,
 341         },
 342 #endif
 343 #ifdef __sparc__
 344         {
 345                 .ctl_name       = KERN_SPARC_REBOOT,
 346                 .procname       = "reboot-cmd",
 347                 .data           = reboot_command,
 348                 .maxlen         = 256,
 349                 .mode           = 0644,
 350                 .proc_handler   = &proc_dostring,
 351                 .strategy       = &sysctl_string,
 352         },
 353         {
 354                 .ctl_name       = KERN_SPARC_STOP_A,
 355                 .procname       = "stop-a",
 356                 .data           = &stop_a_enabled,
 357                 .maxlen         = sizeof (int),
 358                 .mode           = 0644,
 359                 .proc_handler   = &proc_dointvec,
 360         },
 361         {
 362                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 363                 .procname       = "scons-poweroff",
 364                 .data           = &scons_pwroff,
 365                 .maxlen         = sizeof (int),
 366                 .mode           = 0644,
 367                 .proc_handler   = &proc_dointvec,
 368         },
 369 #endif
 370 #ifdef __hppa__
 371         {
 372                 .ctl_name       = KERN_HPPA_PWRSW,
 373                 .procname       = "soft-power",
 374                 .data           = &pwrsw_enabled,
 375                 .maxlen         = sizeof (int),
 376                 .mode           = 0644,
 377                 .proc_handler   = &proc_dointvec,
 378         },
 379         {
 380                 .ctl_name       = KERN_HPPA_UNALIGNED,
 381                 .procname       = "unaligned-trap",
 382                 .data           = &unaligned_enabled,
 383                 .maxlen         = sizeof (int),
 384                 .mode           = 0644,
 385                 .proc_handler   = &proc_dointvec,
 386         },
 387 #endif
 388         {
 389                 .ctl_name       = KERN_CTLALTDEL,
 390                 .procname       = "ctrl-alt-del",
 391                 .data           = &C_A_D,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = &proc_dointvec,
 395         },
 396         {
 397                 .ctl_name       = KERN_PRINTK,
 398                 .procname       = "printk",
 399                 .data           = &console_loglevel,
 400                 .maxlen         = 4*sizeof(int),
 401                 .mode           = 0644,
 402                 .proc_handler   = &proc_dointvec,
 403         },
 404 #ifdef CONFIG_KMOD
 405         {
 406                 .ctl_name       = KERN_MODPROBE,
 407                 .procname       = "modprobe",
 408                 .data           = &modprobe_path,
 409                 .maxlen         = KMOD_PATH_LEN,
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dostring,
 412                 .strategy       = &sysctl_string,
 413         },
 414 #endif
 415 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 416         {
 417                 .ctl_name       = KERN_HOTPLUG,
 418                 .procname       = "hotplug",
 419                 .data           = &uevent_helper,
 420                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 421                 .mode           = 0644,
 422                 .proc_handler   = &proc_dostring,
 423                 .strategy       = &sysctl_string,
 424         },
 425 #endif
 426 #ifdef CONFIG_CHR_DEV_SG
 427         {
 428                 .ctl_name       = KERN_SG_BIG_BUFF,
 429                 .procname       = "sg-big-buff",
 430                 .data           = &sg_big_buff,
 431                 .maxlen         = sizeof (int),
 432                 .mode           = 0444,
 433                 .proc_handler   = &proc_dointvec,
 434         },
 435 #endif
 436 #ifdef CONFIG_BSD_PROCESS_ACCT
 437         {
 438                 .ctl_name       = KERN_ACCT,
 439                 .procname       = "acct",
 440                 .data           = &acct_parm,
 441                 .maxlen         = 3*sizeof(int),
 442                 .mode           = 0644,
 443                 .proc_handler   = &proc_dointvec,
 444         },
 445 #endif
 446 #ifdef CONFIG_MAGIC_SYSRQ
 447         {
 448                 .ctl_name       = KERN_SYSRQ,
 449                 .procname       = "sysrq",
 450                 .data           = &__sysrq_enabled,
 451                 .maxlen         = sizeof (int),
 452                 .mode           = 0644,
 453                 .proc_handler   = &proc_dointvec,
 454         },
 455 #endif
 456 #ifdef CONFIG_PROC_SYSCTL
 457         {
 458                 .ctl_name       = KERN_CADPID,
 459                 .procname       = "cad_pid",
 460                 .data           = NULL,
 461                 .maxlen         = sizeof (int),
 462                 .mode           = 0600,
 463                 .proc_handler   = &proc_do_cad_pid,
 464         },
 465 #endif
 466         {
 467                 .ctl_name       = KERN_MAX_THREADS,
 468                 .procname       = "threads-max",
 469                 .data           = &max_threads,
 470                 .maxlen         = sizeof(int),
 471                 .mode           = 0644,
 472                 .proc_handler   = &proc_dointvec,
 473         },
 474         {
 475                 .ctl_name       = KERN_RANDOM,
 476                 .procname       = "random",
 477                 .mode           = 0555,
 478                 .child          = random_table,
 479         },
 480 #ifdef CONFIG_UNIX98_PTYS
 481         {
 482                 .ctl_name       = KERN_PTY,
 483                 .procname       = "pty",
 484                 .mode           = 0555,
 485                 .child          = pty_table,
 486         },
 487 #endif
 488         {
 489                 .ctl_name       = KERN_OVERFLOWUID,
 490                 .procname       = "overflowuid",
 491                 .data           = &overflowuid,
 492                 .maxlen         = sizeof(int),
 493                 .mode           = 0644,
 494                 .proc_handler   = &proc_dointvec_minmax,
 495                 .strategy       = &sysctl_intvec,
 496                 .extra1         = &minolduid,
 497                 .extra2         = &maxolduid,
 498         },
 499         {
 500                 .ctl_name       = KERN_OVERFLOWGID,
 501                 .procname       = "overflowgid",
 502                 .data           = &overflowgid,
 503                 .maxlen         = sizeof(int),
 504                 .mode           = 0644,
 505                 .proc_handler   = &proc_dointvec_minmax,
 506                 .strategy       = &sysctl_intvec,
 507                 .extra1         = &minolduid,
 508                 .extra2         = &maxolduid,
 509         },
 510 #ifdef CONFIG_S390
 511 #ifdef CONFIG_MATHEMU
 512         {
 513                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 514                 .procname       = "ieee_emulation_warnings",
 515                 .data           = &sysctl_ieee_emulation_warnings,
 516                 .maxlen         = sizeof(int),
 517                 .mode           = 0644,
 518                 .proc_handler   = &proc_dointvec,
 519         },
 520 #endif
 521 #ifdef CONFIG_NO_IDLE_HZ
 522         {
 523                 .ctl_name       = KERN_HZ_TIMER,
 524                 .procname       = "hz_timer",
 525                 .data           = &sysctl_hz_timer,
 526                 .maxlen         = sizeof(int),
 527                 .mode           = 0644,
 528                 .proc_handler   = &proc_dointvec,
 529         },
 530 #endif
 531         {
 532                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 533                 .procname       = "userprocess_debug",
 534                 .data           = &sysctl_userprocess_debug,
 535                 .maxlen         = sizeof(int),
 536                 .mode           = 0644,
 537                 .proc_handler   = &proc_dointvec,
 538         },
 539 #endif
 540         {
 541                 .ctl_name       = KERN_PIDMAX,
 542                 .procname       = "pid_max",
 543                 .data           = &pid_max,
 544                 .maxlen         = sizeof (int),
 545                 .mode           = 0644,
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .strategy       = sysctl_intvec,
 548                 .extra1         = &pid_max_min,
 549                 .extra2         = &pid_max_max,
 550         },
 551         {
 552                 .ctl_name       = KERN_PANIC_ON_OOPS,
 553                 .procname       = "panic_on_oops",
 554                 .data           = &panic_on_oops,
 555                 .maxlen         = sizeof(int),
 556                 .mode           = 0644,
 557                 .proc_handler   = &proc_dointvec,
 558         },
 559         {
 560                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 561                 .procname       = "printk_ratelimit",
 562                 .data           = &printk_ratelimit_jiffies,
 563                 .maxlen         = sizeof(int),
 564                 .mode           = 0644,
 565                 .proc_handler   = &proc_dointvec_jiffies,
 566                 .strategy       = &sysctl_jiffies,
 567         },
 568         {
 569                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 570                 .procname       = "printk_ratelimit_burst",
 571                 .data           = &printk_ratelimit_burst,
 572                 .maxlen         = sizeof(int),
 573                 .mode           = 0644,
 574                 .proc_handler   = &proc_dointvec,
 575         },
 576         {
 577                 .ctl_name       = KERN_NGROUPS_MAX,
 578                 .procname       = "ngroups_max",
 579                 .data           = &ngroups_max,
 580                 .maxlen         = sizeof (int),
 581                 .mode           = 0444,
 582                 .proc_handler   = &proc_dointvec,
 583         },
 584 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 585         {
 586                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 587                 .procname       = "unknown_nmi_panic",
 588                 .data           = &unknown_nmi_panic,
 589                 .maxlen         = sizeof (int),
 590                 .mode           = 0644,
 591                 .proc_handler   = &proc_dointvec,
 592         },
 593         {
 594                 .ctl_name       = KERN_NMI_WATCHDOG,
 595                 .procname       = "nmi_watchdog",
 596                 .data           = &nmi_watchdog_enabled,
 597                 .maxlen         = sizeof (int),
 598                 .mode           = 0644,
 599                 .proc_handler   = &proc_nmi_enabled,
 600         },
 601 #endif
 602 #if defined(CONFIG_X86)
 603         {
 604                 .ctl_name       = KERN_PANIC_ON_NMI,
 605                 .procname       = "panic_on_unrecovered_nmi",
 606                 .data           = &panic_on_unrecovered_nmi,
 607                 .maxlen         = sizeof(int),
 608                 .mode           = 0644,
 609                 .proc_handler   = &proc_dointvec,
 610         },
 611         {
 612                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 613                 .procname       = "bootloader_type",
 614                 .data           = &bootloader_type,
 615                 .maxlen         = sizeof (int),
 616                 .mode           = 0444,
 617                 .proc_handler   = &proc_dointvec,
 618         },
 619         {
 620                 .ctl_name       = CTL_UNNUMBERED,
 621                 .procname       = "kstack_depth_to_print",
 622                 .data           = &kstack_depth_to_print,
 623                 .maxlen         = sizeof(int),
 624                 .mode           = 0644,
 625                 .proc_handler   = &proc_dointvec,
 626         },
 627 #endif
 628 #if defined(CONFIG_MMU)
 629         {
 630                 .ctl_name       = KERN_RANDOMIZE,
 631                 .procname       = "randomize_va_space",
 632                 .data           = &randomize_va_space,
 633                 .maxlen         = sizeof(int),
 634                 .mode           = 0644,
 635                 .proc_handler   = &proc_dointvec,
 636         },
 637 #endif
 638 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 639         {
 640                 .ctl_name       = KERN_SPIN_RETRY,
 641                 .procname       = "spin_retry",
 642                 .data           = &spin_retry,
 643                 .maxlen         = sizeof (int),
 644                 .mode           = 0644,
 645                 .proc_handler   = &proc_dointvec,
 646         },
 647 #endif
 648 #ifdef CONFIG_ACPI_SLEEP
 649         {
 650                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 651                 .procname       = "acpi_video_flags",
 652                 .data           = &acpi_video_flags,
 653                 .maxlen         = sizeof (unsigned long),
 654                 .mode           = 0644,
 655                 .proc_handler   = &proc_doulongvec_minmax,
 656         },
 657 #endif
 658 #ifdef CONFIG_IA64
 659         {
 660                 .ctl_name       = KERN_IA64_UNALIGNED,
 661                 .procname       = "ignore-unaligned-usertrap",
 662                 .data           = &no_unaligned_warning,
 663                 .maxlen         = sizeof (int),
 664                 .mode           = 0644,
 665                 .proc_handler   = &proc_dointvec,
 666         },
 667 #endif
 668 #ifdef CONFIG_COMPAT
 669         {
 670                 .ctl_name       = KERN_COMPAT_LOG,
 671                 .procname       = "compat-log",
 672                 .data           = &compat_log,
 673                 .maxlen         = sizeof (int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678 #ifdef CONFIG_RT_MUTEXES
 679         {
 680                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 681                 .procname       = "max_lock_depth",
 682                 .data           = &max_lock_depth,
 683                 .maxlen         = sizeof(int),
 684                 .mode           = 0644,
 685                 .proc_handler   = &proc_dointvec,
 686         },
 687 #endif
 688 #ifdef CONFIG_PROC_FS
 689         {
 690                 .ctl_name       = CTL_UNNUMBERED,
 691                 .procname       = "maps_protect",
 692                 .data           = &maps_protect,
 693                 .maxlen         = sizeof(int),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_dointvec,
 696         },
 697 #endif
 698
 699         { .ctl_name = 0 }
 700 };
 701
 702 /* Constants for minimum and maximum testing in vm_table.
 703    We use these as one-element integer vectors. */
 704 static int zero;
 705 static int one_hundred = 100;
 706
 707
 708 static ctl_table vm_table[] = {
 709         {
 710                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 711                 .procname       = "overcommit_memory",
 712                 .data           = &sysctl_overcommit_memory,
 713                 .maxlen         = sizeof(sysctl_overcommit_memory),
 714                 .mode           = 0644,
 715                 .proc_handler   = &proc_dointvec,
 716         },
 717         {
 718                 .ctl_name       = VM_PANIC_ON_OOM,
 719                 .procname       = "panic_on_oom",
 720                 .data           = &sysctl_panic_on_oom,
 721                 .maxlen         = sizeof(sysctl_panic_on_oom),
 722                 .mode           = 0644,
 723                 .proc_handler   = &proc_dointvec,
 724         },
 725         {
 726                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 727                 .procname       = "overcommit_ratio",
 728                 .data           = &sysctl_overcommit_ratio,
 729                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 730                 .mode           = 0644,
 731                 .proc_handler   = &proc_dointvec,
 732         },
 733         {
 734                 .ctl_name       = VM_PAGE_CLUSTER,
 735                 .procname       = "page-cluster",
 736                 .data           = &page_cluster,
 737                 .maxlen         = sizeof(int),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec,
 740         },
 741         {
 742                 .ctl_name       = VM_DIRTY_BACKGROUND,
 743                 .procname       = "dirty_background_ratio",
 744                 .data           = &dirty_background_ratio,
 745                 .maxlen         = sizeof(dirty_background_ratio),
 746                 .mode           = 0644,
 747                 .proc_handler   = &proc_dointvec_minmax,
 748                 .strategy       = &sysctl_intvec,
 749                 .extra1         = &zero,
 750                 .extra2         = &one_hundred,
 751         },
 752         {
 753                 .ctl_name       = VM_DIRTY_RATIO,
 754                 .procname       = "dirty_ratio",
 755                 .data           = &vm_dirty_ratio,
 756                 .maxlen         = sizeof(vm_dirty_ratio),
 757                 .mode           = 0644,
 758                 .proc_handler   = &proc_dointvec_minmax,
 759                 .strategy       = &sysctl_intvec,
 760                 .extra1         = &zero,
 761                 .extra2         = &one_hundred,
 762         },
 763         {
 764                 .ctl_name       = VM_DIRTY_WB_CS,
 765                 .procname       = "dirty_writeback_centisecs",
 766                 .data           = &dirty_writeback_interval,
 767                 .maxlen         = sizeof(dirty_writeback_interval),
 768                 .mode           = 0644,
 769                 .proc_handler   = &dirty_writeback_centisecs_handler,
 770         },
 771         {
 772                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 773                 .procname       = "dirty_expire_centisecs",
 774                 .data           = &dirty_expire_interval,
 775                 .maxlen         = sizeof(dirty_expire_interval),
 776                 .mode           = 0644,
 777                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 778         },
 779         {
 780                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 781                 .procname       = "nr_pdflush_threads",
 782                 .data           = &nr_pdflush_threads,
 783                 .maxlen         = sizeof nr_pdflush_threads,
 784                 .mode           = 0444 /* read-only*/,
 785                 .proc_handler   = &proc_dointvec,
 786         },
 787         {
 788                 .ctl_name       = VM_SWAPPINESS,
 789                 .procname       = "swappiness",
 790                 .data           = &vm_swappiness,
 791                 .maxlen         = sizeof(vm_swappiness),
 792                 .mode           = 0644,
 793                 .proc_handler   = &proc_dointvec_minmax,
 794                 .strategy       = &sysctl_intvec,
 795                 .extra1         = &zero,
 796                 .extra2         = &one_hundred,
 797         },
 798 #ifdef CONFIG_HUGETLB_PAGE
 799          {
 800                 .ctl_name       = VM_HUGETLB_PAGES,
 801                 .procname       = "nr_hugepages",
 802                 .data           = &max_huge_pages,
 803                 .maxlen         = sizeof(unsigned long),
 804                 .mode           = 0644,
 805                 .proc_handler   = &hugetlb_sysctl_handler,
 806                 .extra1         = (void *)&hugetlb_zero,
 807                 .extra2         = (void *)&hugetlb_infinity,
 808          },
 809          {
 810                 .ctl_name       = VM_HUGETLB_GROUP,
 811                 .procname       = "hugetlb_shm_group",
 812                 .data           = &sysctl_hugetlb_shm_group,
 813                 .maxlen         = sizeof(gid_t),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dointvec,
 816          },
 817 #endif
 818         {
 819                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 820                 .procname       = "lowmem_reserve_ratio",
 821                 .data           = &sysctl_lowmem_reserve_ratio,
 822                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 823                 .mode           = 0644,
 824                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 825                 .strategy       = &sysctl_intvec,
 826         },
 827         {
 828                 .ctl_name       = VM_DROP_PAGECACHE,
 829                 .procname       = "drop_caches",
 830                 .data           = &sysctl_drop_caches,
 831                 .maxlen         = sizeof(int),
 832                 .mode           = 0644,
 833                 .proc_handler   = drop_caches_sysctl_handler,
 834                 .strategy       = &sysctl_intvec,
 835         },
 836         {
 837                 .ctl_name       = VM_MIN_FREE_KBYTES,
 838                 .procname       = "min_free_kbytes",
 839                 .data           = &min_free_kbytes,
 840                 .maxlen         = sizeof(min_free_kbytes),
 841                 .mode           = 0644,
 842                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 843                 .strategy       = &sysctl_intvec,
 844                 .extra1         = &zero,
 845         },
 846         {
 847                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 848                 .procname       = "percpu_pagelist_fraction",
 849                 .data           = &percpu_pagelist_fraction,
 850                 .maxlen         = sizeof(percpu_pagelist_fraction),
 851                 .mode           = 0644,
 852                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 853                 .strategy       = &sysctl_intvec,
 854                 .extra1         = &min_percpu_pagelist_fract,
 855         },
 856 #ifdef CONFIG_MMU
 857         {
 858                 .ctl_name       = VM_MAX_MAP_COUNT,
 859                 .procname       = "max_map_count",
 860                 .data           = &sysctl_max_map_count,
 861                 .maxlen         = sizeof(sysctl_max_map_count),
 862                 .mode           = 0644,
 863                 .proc_handler   = &proc_dointvec
 864         },
 865 #endif
 866         {
 867                 .ctl_name       = VM_LAPTOP_MODE,
 868                 .procname       = "laptop_mode",
 869                 .data           = &laptop_mode,
 870                 .maxlen         = sizeof(laptop_mode),
 871                 .mode           = 0644,
 872                 .proc_handler   = &proc_dointvec_jiffies,
 873                 .strategy       = &sysctl_jiffies,
 874         },
 875         {
 876                 .ctl_name       = VM_BLOCK_DUMP,
 877                 .procname       = "block_dump",
 878                 .data           = &block_dump,
 879                 .maxlen         = sizeof(block_dump),
 880                 .mode           = 0644,
 881                 .proc_handler   = &proc_dointvec,
 882                 .strategy       = &sysctl_intvec,
 883                 .extra1         = &zero,
 884         },
 885         {
 886                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 887                 .procname       = "vfs_cache_pressure",
 888                 .data           = &sysctl_vfs_cache_pressure,
 889                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 890                 .mode           = 0644,
 891                 .proc_handler   = &proc_dointvec,
 892                 .strategy       = &sysctl_intvec,
 893                 .extra1         = &zero,
 894         },
 895 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 896         {
 897                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 898                 .procname       = "legacy_va_layout",
 899                 .data           = &sysctl_legacy_va_layout,
 900                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 901                 .mode           = 0644,
 902                 .proc_handler   = &proc_dointvec,
 903                 .strategy       = &sysctl_intvec,
 904                 .extra1         = &zero,
 905         },
 906 #endif
 907 #ifdef CONFIG_NUMA
 908         {
 909                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 910                 .procname       = "zone_reclaim_mode",
 911                 .data           = &zone_reclaim_mode,
 912                 .maxlen         = sizeof(zone_reclaim_mode),
 913                 .mode           = 0644,
 914                 .proc_handler   = &proc_dointvec,
 915                 .strategy       = &sysctl_intvec,
 916                 .extra1         = &zero,
 917         },
 918         {
 919                 .ctl_name       = VM_MIN_UNMAPPED,
 920                 .procname       = "min_unmapped_ratio",
 921                 .data           = &sysctl_min_unmapped_ratio,
 922                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 923                 .mode           = 0644,
 924                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 925                 .strategy       = &sysctl_intvec,
 926                 .extra1         = &zero,
 927                 .extra2         = &one_hundred,
 928         },
 929         {
 930                 .ctl_name       = VM_MIN_SLAB,
 931                 .procname       = "min_slab_ratio",
 932                 .data           = &sysctl_min_slab_ratio,
 933                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 934                 .mode           = 0644,
 935                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 936                 .strategy       = &sysctl_intvec,
 937                 .extra1         = &zero,
 938                 .extra2         = &one_hundred,
 939         },
 940 #endif
 941 #ifdef CONFIG_SMP
 942         {
 943                 .ctl_name       = CTL_UNNUMBERED,
 944                 .procname       = "stat_interval",
 945                 .data           = &sysctl_stat_interval,
 946                 .maxlen         = sizeof(sysctl_stat_interval),
 947                 .mode           = 0644,
 948                 .proc_handler   = &proc_dointvec_jiffies,
 949                 .strategy       = &sysctl_jiffies,
 950         },
 951 #endif
 952 #ifdef CONFIG_SECURITY
 953         {
 954                 .ctl_name       = CTL_UNNUMBERED,
 955                 .procname       = "mmap_min_addr",
 956                 .data           = &mmap_min_addr,
 957                 .maxlen         = sizeof(unsigned long),
 958                 .mode           = 0644,
 959                 .proc_handler   = &proc_doulongvec_minmax,
 960         },
 961 #endif
 962 #if defined(CONFIG_X86_32) || \
 963    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
 964         {
 965                 .ctl_name       = VM_VDSO_ENABLED,
 966                 .procname       = "vdso_enabled",
 967                 .data           = &vdso_enabled,
 968                 .maxlen         = sizeof(vdso_enabled),
 969                 .mode           = 0644,
 970                 .proc_handler   = &proc_dointvec,
 971                 .strategy       = &sysctl_intvec,
 972                 .extra1         = &zero,
 973         },
 974 #endif
 975         { .ctl_name = 0 }
 976 };
 977
 978 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
 979 static ctl_table binfmt_misc_table[] = {
 980         { .ctl_name = 0 }
 981 };
 982 #endif
 983
 984 static ctl_table fs_table[] = {
 985         {
 986                 .ctl_name       = FS_NRINODE,
 987                 .procname       = "inode-nr",
 988                 .data           = &inodes_stat,
 989                 .maxlen         = 2*sizeof(int),
 990                 .mode           = 0444,
 991                 .proc_handler   = &proc_dointvec,
 992         },
 993         {
 994                 .ctl_name       = FS_STATINODE,
 995                 .procname       = "inode-state",
 996                 .data           = &inodes_stat,
 997                 .maxlen         = 7*sizeof(int),
 998                 .mode           = 0444,
 999                 .proc_handler   = &proc_dointvec,
1000         },
1001         {
1002                 .ctl_name       = FS_NRFILE,
1003                 .procname       = "file-nr",
1004                 .data           = &files_stat,
1005                 .maxlen         = 3*sizeof(int),
1006                 .mode           = 0444,
1007                 .proc_handler   = &proc_nr_files,
1008         },
1009         {
1010                 .ctl_name       = FS_MAXFILE,
1011                 .procname       = "file-max",
1012                 .data           = &files_stat.max_files,
1013                 .maxlen         = sizeof(int),
1014                 .mode           = 0644,
1015                 .proc_handler   = &proc_dointvec,
1016         },
1017         {
1018                 .ctl_name       = FS_DENTRY,
1019                 .procname       = "dentry-state",
1020                 .data           = &dentry_stat,
1021                 .maxlen         = 6*sizeof(int),
1022                 .mode           = 0444,
1023                 .proc_handler   = &proc_dointvec,
1024         },
1025         {
1026                 .ctl_name       = FS_OVERFLOWUID,
1027                 .procname       = "overflowuid",
1028                 .data           = &fs_overflowuid,
1029                 .maxlen         = sizeof(int),
1030                 .mode           = 0644,
1031                 .proc_handler   = &proc_dointvec_minmax,
1032                 .strategy       = &sysctl_intvec,
1033                 .extra1         = &minolduid,
1034                 .extra2         = &maxolduid,
1035         },
1036         {
1037                 .ctl_name       = FS_OVERFLOWGID,
1038                 .procname       = "overflowgid",
1039                 .data           = &fs_overflowgid,
1040                 .maxlen         = sizeof(int),
1041                 .mode           = 0644,
1042                 .proc_handler   = &proc_dointvec_minmax,
1043                 .strategy       = &sysctl_intvec,
1044                 .extra1         = &minolduid,
1045                 .extra2         = &maxolduid,
1046         },
1047         {
1048                 .ctl_name       = FS_LEASES,
1049                 .procname       = "leases-enable",
1050                 .data           = &leases_enable,
1051                 .maxlen         = sizeof(int),
1052                 .mode           = 0644,
1053                 .proc_handler   = &proc_dointvec,
1054         },
1055 #ifdef CONFIG_DNOTIFY
1056         {
1057                 .ctl_name       = FS_DIR_NOTIFY,
1058                 .procname       = "dir-notify-enable",
1059                 .data           = &dir_notify_enable,
1060                 .maxlen         = sizeof(int),
1061                 .mode           = 0644,
1062                 .proc_handler   = &proc_dointvec,
1063         },
1064 #endif
1065 #ifdef CONFIG_MMU
1066         {
1067                 .ctl_name       = FS_LEASE_TIME,
1068                 .procname       = "lease-break-time",
1069                 .data           = &lease_break_time,
1070                 .maxlen         = sizeof(int),
1071                 .mode           = 0644,
1072                 .proc_handler   = &proc_dointvec,
1073         },
1074         {
1075                 .ctl_name       = FS_AIO_NR,
1076                 .procname       = "aio-nr",
1077                 .data           = &aio_nr,
1078                 .maxlen         = sizeof(aio_nr),
1079                 .mode           = 0444,
1080                 .proc_handler   = &proc_doulongvec_minmax,
1081         },
1082         {
1083                 .ctl_name       = FS_AIO_MAX_NR,
1084                 .procname       = "aio-max-nr",
1085                 .data           = &aio_max_nr,
1086                 .maxlen         = sizeof(aio_max_nr),
1087                 .mode           = 0644,
1088                 .proc_handler   = &proc_doulongvec_minmax,
1089         },
1090 #ifdef CONFIG_INOTIFY_USER
1091         {
1092                 .ctl_name       = FS_INOTIFY,
1093                 .procname       = "inotify",
1094                 .mode           = 0555,
1095                 .child          = inotify_table,
1096         },
1097 #endif
1098 #endif
1099         {
1100                 .ctl_name       = KERN_SETUID_DUMPABLE,
1101                 .procname       = "suid_dumpable",
1102                 .data           = &suid_dumpable,
1103                 .maxlen         = sizeof(int),
1104                 .mode           = 0644,
1105                 .proc_handler   = &proc_dointvec,
1106         },
1107 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1108         {
1109                 .ctl_name       = CTL_UNNUMBERED,
1110                 .procname       = "binfmt_misc",
1111                 .mode           = 0555,
1112                 .child          = binfmt_misc_table,
1113         },
1114 #endif
1115         { .ctl_name = 0 }
1116 };
1117
1118 static ctl_table debug_table[] = {
1119         { .ctl_name = 0 }
1120 };
1121
1122 static ctl_table dev_table[] = {
1123         { .ctl_name = 0 }
1124 };
1125
1126 static DEFINE_SPINLOCK(sysctl_lock);
1127
1128 /* called under sysctl_lock */
1129 static int use_table(struct ctl_table_header *p)
1130 {
1131         if (unlikely(p->unregistering))
1132                 return 0;
1133         p->used++;
1134         return 1;
1135 }
1136
1137 /* called under sysctl_lock */
1138 static void unuse_table(struct ctl_table_header *p)
1139 {
1140         if (!--p->used)
1141                 if (unlikely(p->unregistering))
1142                         complete(p->unregistering);
1143 }
1144
1145 /* called under sysctl_lock, will reacquire if has to wait */
1146 static void start_unregistering(struct ctl_table_header *p)
1147 {
1148         /*
1149          * if p->used is 0, nobody will ever touch that entry again;
1150          * we'll eliminate all paths to it before dropping sysctl_lock
1151          */
1152         if (unlikely(p->used)) {
1153                 struct completion wait;
1154                 init_completion(&wait);
1155                 p->unregistering = &wait;
1156                 spin_unlock(&sysctl_lock);
1157                 wait_for_completion(&wait);
1158                 spin_lock(&sysctl_lock);
1159         }
1160         /*
1161          * do not remove from the list until nobody holds it; walking the
1162          * list in do_sysctl() relies on that.
1163          */
1164         list_del_init(&p->ctl_entry);
1165 }
1166
1167 void sysctl_head_finish(struct ctl_table_header *head)
1168 {
1169         if (!head)
1170                 return;
1171         spin_lock(&sysctl_lock);
1172         unuse_table(head);
1173         spin_unlock(&sysctl_lock);
1174 }
1175
1176 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1177 {
1178         struct ctl_table_header *head;
1179         struct list_head *tmp;
1180         spin_lock(&sysctl_lock);
1181         if (prev) {
1182                 tmp = &prev->ctl_entry;
1183                 unuse_table(prev);
1184                 goto next;
1185         }
1186         tmp = &root_table_header.ctl_entry;
1187         for (;;) {
1188                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1189
1190                 if (!use_table(head))
1191                         goto next;
1192                 spin_unlock(&sysctl_lock);
1193                 return head;
1194         next:
1195                 tmp = tmp->next;
1196                 if (tmp == &root_table_header.ctl_entry)
1197                         break;
1198         }
1199         spin_unlock(&sysctl_lock);
1200         return NULL;
1201 }
1202
1203 #ifdef CONFIG_SYSCTL_SYSCALL
1204 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1205                void __user *newval, size_t newlen)
1206 {
1207         struct ctl_table_header *head;
1208         int error = -ENOTDIR;
1209
1210         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1211                 return -ENOTDIR;
1212         if (oldval) {
1213                 int old_len;
1214                 if (!oldlenp || get_user(old_len, oldlenp))
1215                         return -EFAULT;
1216         }
1217
1218         for (head = sysctl_head_next(NULL); head;
1219                         head = sysctl_head_next(head)) {
1220                 error = parse_table(name, nlen, oldval, oldlenp,
1221                                         newval, newlen, head->ctl_table);
1222                 if (error != -ENOTDIR) {
1223                         sysctl_head_finish(head);
1224                         break;
1225                 }
1226         }
1227         return error;
1228 }
1229
1230 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1231 {
1232         struct __sysctl_args tmp;
1233         int error;
1234
1235         if (copy_from_user(&tmp, args, sizeof(tmp)))
1236                 return -EFAULT;
1237
1238         lock_kernel();
1239         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1240                           tmp.newval, tmp.newlen);
1241         unlock_kernel();
1242         return error;
1243 }
1244 #endif /* CONFIG_SYSCTL_SYSCALL */
1245
1246 /*
1247  * sysctl_perm does NOT grant the superuser all rights automatically, because
1248  * some sysctl variables are readonly even to root.
1249  */
1250
1251 static int test_perm(int mode, int op)
1252 {
1253         if (!current->euid)
1254                 mode >>= 6;
1255         else if (in_egroup_p(0))
1256                 mode >>= 3;
1257         if ((mode & op & 0007) == op)
1258                 return 0;
1259         return -EACCES;
1260 }
1261
1262 int sysctl_perm(ctl_table *table, int op)
1263 {
1264         int error;
1265         error = security_sysctl(table, op);
1266         if (error)
1267                 return error;
1268         return test_perm(table->mode, op);
1269 }
1270
1271 #ifdef CONFIG_SYSCTL_SYSCALL
1272 static int parse_table(int __user *name, int nlen,
1273                        void __user *oldval, size_t __user *oldlenp,
1274                        void __user *newval, size_t newlen,
1275                        ctl_table *table)
1276 {
1277         int n;
1278 repeat:
1279         if (!nlen)
1280                 return -ENOTDIR;
1281         if (get_user(n, name))
1282                 return -EFAULT;
1283         for ( ; table->ctl_name || table->procname; table++) {
1284                 if (!table->ctl_name)
1285                         continue;
1286                 if (n == table->ctl_name) {
1287                         int error;
1288                         if (table->child) {
1289                                 if (sysctl_perm(table, 001))
1290                                         return -EPERM;
1291                                 name++;
1292                                 nlen--;
1293                                 table = table->child;
1294                                 goto repeat;
1295                         }
1296                         error = do_sysctl_strategy(table, name, nlen,
1297                                                    oldval, oldlenp,
1298                                                    newval, newlen);
1299                         return error;
1300                 }
1301         }
1302         return -ENOTDIR;
1303 }
1304
1305 /* Perform the actual read/write of a sysctl table entry. */
1306 int do_sysctl_strategy (ctl_table *table,
1307                         int __user *name, int nlen,
1308                         void __user *oldval, size_t __user *oldlenp,
1309                         void __user *newval, size_t newlen)
1310 {
1311         int op = 0, rc;
1312         size_t len;
1313
1314         if (oldval)
1315                 op |= 004;
1316         if (newval)
1317                 op |= 002;
1318         if (sysctl_perm(table, op))
1319                 return -EPERM;
1320
1321         if (table->strategy) {
1322                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1323                                      newval, newlen);
1324                 if (rc < 0)
1325                         return rc;
1326                 if (rc > 0)
1327                         return 0;
1328         }
1329
1330         /* If there is no strategy routine, or if the strategy returns
1331          * zero, proceed with automatic r/w */
1332         if (table->data && table->maxlen) {
1333                 if (oldval && oldlenp) {
1334                         if (get_user(len, oldlenp))
1335                                 return -EFAULT;
1336                         if (len) {
1337                                 if (len > table->maxlen)
1338                                         len = table->maxlen;
1339                                 if(copy_to_user(oldval, table->data, len))
1340                                         return -EFAULT;
1341                                 if(put_user(len, oldlenp))
1342                                         return -EFAULT;
1343                         }
1344                 }
1345                 if (newval && newlen) {
1346                         len = newlen;
1347                         if (len > table->maxlen)
1348                                 len = table->maxlen;
1349                         if(copy_from_user(table->data, newval, len))
1350                                 return -EFAULT;
1351                 }
1352         }
1353         return 0;
1354 }
1355 #endif /* CONFIG_SYSCTL_SYSCALL */
1356
1357 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1358 {
1359         for (; table->ctl_name || table->procname; table++) {
1360                 table->parent = parent;
1361                 if (table->child)
1362                         sysctl_set_parent(table, table->child);
1363         }
1364 }
1365
1366 static __init int sysctl_init(void)
1367 {
1368         sysctl_set_parent(NULL, root_table);
1369         return 0;
1370 }
1371
1372 core_initcall(sysctl_init);
1373
1374 /**
1375  * register_sysctl_table - register a sysctl hierarchy
1376  * @table: the top-level table structure
1377  *
1378  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1379  * array. An entry with a ctl_name of 0 terminates the table.
1380  *
1381  * The members of the &ctl_table structure are used as follows:
1382  *
1383  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1384  *            must be unique within that level of sysctl
1385  *
1386  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1387  *            enter a sysctl file
1388  *
1389  * data - a pointer to data for use by proc_handler
1390  *
1391  * maxlen - the maximum size in bytes of the data
1392  *
1393  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1394  *
1395  * child - a pointer to the child sysctl table if this entry is a directory, or
1396  *         %NULL.
1397  *
1398  * proc_handler - the text handler routine (described below)
1399  *
1400  * strategy - the strategy routine (described below)
1401  *
1402  * de - for internal use by the sysctl routines
1403  *
1404  * extra1, extra2 - extra pointers usable by the proc handler routines
1405  *
1406  * Leaf nodes in the sysctl tree will be represented by a single file
1407  * under /proc; non-leaf nodes will be represented by directories.
1408  *
1409  * sysctl(2) can automatically manage read and write requests through
1410  * the sysctl table.  The data and maxlen fields of the ctl_table
1411  * struct enable minimal validation of the values being written to be
1412  * performed, and the mode field allows minimal authentication.
1413  *
1414  * More sophisticated management can be enabled by the provision of a
1415  * strategy routine with the table entry.  This will be called before
1416  * any automatic read or write of the data is performed.
1417  *
1418  * The strategy routine may return
1419  *
1420  * < 0 - Error occurred (error is passed to user process)
1421  *
1422  * 0   - OK - proceed with automatic read or write.
1423  *
1424  * > 0 - OK - read or write has been done by the strategy routine, so
1425  *       return immediately.
1426  *
1427  * There must be a proc_handler routine for any terminal nodes
1428  * mirrored under /proc/sys (non-terminals are handled by a built-in
1429  * directory handler).  Several default handlers are available to
1430  * cover common cases -
1431  *
1432  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1433  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1434  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1435  *
1436  * It is the handler's job to read the input buffer from user memory
1437  * and process it. The handler should return 0 on success.
1438  *
1439  * This routine returns %NULL on a failure to register, and a pointer
1440  * to the table header on success.
1441  */
1442 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1443 {
1444         struct ctl_table_header *tmp;
1445         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1446         if (!tmp)
1447                 return NULL;
1448         tmp->ctl_table = table;
1449         INIT_LIST_HEAD(&tmp->ctl_entry);
1450         tmp->used = 0;
1451         tmp->unregistering = NULL;
1452         sysctl_set_parent(NULL, table);
1453         spin_lock(&sysctl_lock);
1454         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1455         spin_unlock(&sysctl_lock);
1456         return tmp;
1457 }
1458
1459 /**
1460  * unregister_sysctl_table - unregister a sysctl table hierarchy
1461  * @header: the header returned from register_sysctl_table
1462  *
1463  * Unregisters the sysctl table and all children. proc entries may not
1464  * actually be removed until they are no longer used by anyone.
1465  */
1466 void unregister_sysctl_table(struct ctl_table_header * header)
1467 {
1468         might_sleep();
1469         spin_lock(&sysctl_lock);
1470         start_unregistering(header);
1471         spin_unlock(&sysctl_lock);
1472         kfree(header);
1473 }
1474
1475 #else /* !CONFIG_SYSCTL */
1476 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1477 {
1478         return NULL;
1479 }
1480
1481 void unregister_sysctl_table(struct ctl_table_header * table)
1482 {
1483 }
1484
1485 #endif /* CONFIG_SYSCTL */
1486
1487 /*
1488  * /proc/sys support
1489  */
1490
1491 #ifdef CONFIG_PROC_SYSCTL
1492
1493 static int _proc_do_string(void* data, int maxlen, int write,
1494                            struct file *filp, void __user *buffer,
1495                            size_t *lenp, loff_t *ppos)
1496 {
1497         size_t len;
1498         char __user *p;
1499         char c;
1500
1501         if (!data || !maxlen || !*lenp) {
1502                 *lenp = 0;
1503                 return 0;
1504         }
1505
1506         if (write) {
1507                 len = 0;
1508                 p = buffer;
1509                 while (len < *lenp) {
1510                         if (get_user(c, p++))
1511                                 return -EFAULT;
1512                         if (c == 0 || c == '\n')
1513                                 break;
1514                         len++;
1515                 }
1516                 if (len >= maxlen)
1517                         len = maxlen-1;
1518                 if(copy_from_user(data, buffer, len))
1519                         return -EFAULT;
1520                 ((char *) data)[len] = 0;
1521                 *ppos += *lenp;
1522         } else {
1523                 len = strlen(data);
1524                 if (len > maxlen)
1525                         len = maxlen;
1526
1527                 if (*ppos > len) {
1528                         *lenp = 0;
1529                         return 0;
1530                 }
1531
1532                 data += *ppos;
1533                 len  -= *ppos;
1534
1535                 if (len > *lenp)
1536                         len = *lenp;
1537                 if (len)
1538                         if(copy_to_user(buffer, data, len))
1539                                 return -EFAULT;
1540                 if (len < *lenp) {
1541                         if(put_user('\n', ((char __user *) buffer) + len))
1542                                 return -EFAULT;
1543                         len++;
1544                 }
1545                 *lenp = len;
1546                 *ppos += len;
1547         }
1548         return 0;
1549 }
1550
1551 /**
1552  * proc_dostring - read a string sysctl
1553  * @table: the sysctl table
1554  * @write: %TRUE if this is a write to the sysctl file
1555  * @filp: the file structure
1556  * @buffer: the user buffer
1557  * @lenp: the size of the user buffer
1558  * @ppos: file position
1559  *
1560  * Reads/writes a string from/to the user buffer. If the kernel
1561  * buffer provided is not large enough to hold the string, the
1562  * string is truncated. The copied string is %NULL-terminated.
1563  * If the string is being read by the user process, it is copied
1564  * and a newline '\n' is added. It is truncated if the buffer is
1565  * not large enough.
1566  *
1567  * Returns 0 on success.
1568  */
1569 int proc_dostring(ctl_table *table, int write, struct file *filp,
1570                   void __user *buffer, size_t *lenp, loff_t *ppos)
1571 {
1572         return _proc_do_string(table->data, table->maxlen, write, filp,
1573                                buffer, lenp, ppos);
1574 }
1575
1576
1577 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1578                                  int *valp,
1579                                  int write, void *data)
1580 {
1581         if (write) {
1582                 *valp = *negp ? -*lvalp : *lvalp;
1583         } else {
1584                 int val = *valp;
1585                 if (val < 0) {
1586                         *negp = -1;
1587                         *lvalp = (unsigned long)-val;
1588                 } else {
1589                         *negp = 0;
1590                         *lvalp = (unsigned long)val;
1591                 }
1592         }
1593         return 0;
1594 }
1595
1596 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1597                   int write, struct file *filp, void __user *buffer,
1598                   size_t *lenp, loff_t *ppos,
1599                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1600                               int write, void *data),
1601                   void *data)
1602 {
1603 #define TMPBUFLEN 21
1604         int *i, vleft, first=1, neg, val;
1605         unsigned long lval;
1606         size_t left, len;
1607
1608         char buf[TMPBUFLEN], *p;
1609         char __user *s = buffer;
1610
1611         if (!tbl_data || !table->maxlen || !*lenp ||
1612             (*ppos && !write)) {
1613                 *lenp = 0;
1614                 return 0;
1615         }
1616
1617         i = (int *) tbl_data;
1618         vleft = table->maxlen / sizeof(*i);
1619         left = *lenp;
1620
1621         if (!conv)
1622                 conv = do_proc_dointvec_conv;
1623
1624         for (; left && vleft--; i++, first=0) {
1625                 if (write) {
1626                         while (left) {
1627                                 char c;
1628                                 if (get_user(c, s))
1629                                         return -EFAULT;
1630                                 if (!isspace(c))
1631                                         break;
1632                                 left--;
1633                                 s++;
1634                         }
1635                         if (!left)
1636                                 break;
1637                         neg = 0;
1638                         len = left;
1639                         if (len > sizeof(buf) - 1)
1640                                 len = sizeof(buf) - 1;
1641                         if (copy_from_user(buf, s, len))
1642                                 return -EFAULT;
1643                         buf[len] = 0;
1644                         p = buf;
1645                         if (*p == '-' && left > 1) {
1646                                 neg = 1;
1647                                 p++;
1648                         }
1649                         if (*p < '0' || *p > '9')
1650                                 break;
1651
1652                         lval = simple_strtoul(p, &p, 0);
1653
1654                         len = p-buf;
1655                         if ((len < left) && *p && !isspace(*p))
1656                                 break;
1657                         if (neg)
1658                                 val = -val;
1659                         s += len;
1660                         left -= len;
1661
1662                         if (conv(&neg, &lval, i, 1, data))
1663                                 break;
1664                 } else {
1665                         p = buf;
1666                         if (!first)
1667                                 *p++ = '\t';
1668
1669                         if (conv(&neg, &lval, i, 0, data))
1670                                 break;
1671
1672                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1673                         len = strlen(buf);
1674                         if (len > left)
1675                                 len = left;
1676                         if(copy_to_user(s, buf, len))
1677                                 return -EFAULT;
1678                         left -= len;
1679                         s += len;
1680                 }
1681         }
1682
1683         if (!write && !first && left) {
1684                 if(put_user('\n', s))
1685                         return -EFAULT;
1686                 left--, s++;
1687         }
1688         if (write) {
1689                 while (left) {
1690                         char c;
1691                         if (get_user(c, s++))
1692                                 return -EFAULT;
1693                         if (!isspace(c))
1694                                 break;
1695                         left--;
1696                 }
1697         }
1698         if (write && first)
1699                 return -EINVAL;
1700         *lenp -= left;
1701         *ppos += *lenp;
1702         return 0;
1703 #undef TMPBUFLEN
1704 }
1705
1706 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1707                   void __user *buffer, size_t *lenp, loff_t *ppos,
1708                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1709                               int write, void *data),
1710                   void *data)
1711 {
1712         return __do_proc_dointvec(table->data, table, write, filp,
1713                         buffer, lenp, ppos, conv, data);
1714 }
1715
1716 /**
1717  * proc_dointvec - read a vector of integers
1718  * @table: the sysctl table
1719  * @write: %TRUE if this is a write to the sysctl file
1720  * @filp: the file structure
1721  * @buffer: the user buffer
1722  * @lenp: the size of the user buffer
1723  * @ppos: file position
1724  *
1725  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1726  * values from/to the user buffer, treated as an ASCII string.
1727  *
1728  * Returns 0 on success.
1729  */
1730 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1731                      void __user *buffer, size_t *lenp, loff_t *ppos)
1732 {
1733     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1734                             NULL,NULL);
1735 }
1736
1737 #define OP_SET  0
1738 #define OP_AND  1
1739 #define OP_OR   2
1740
1741 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1742                                       int *valp,
1743                                       int write, void *data)
1744 {
1745         int op = *(int *)data;
1746         if (write) {
1747                 int val = *negp ? -*lvalp : *lvalp;
1748                 switch(op) {
1749                 case OP_SET:    *valp = val; break;
1750                 case OP_AND:    *valp &= val; break;
1751                 case OP_OR:     *valp |= val; break;
1752                 }
1753         } else {
1754                 int val = *valp;
1755                 if (val < 0) {
1756                         *negp = -1;
1757                         *lvalp = (unsigned long)-val;
1758                 } else {
1759                         *negp = 0;
1760                         *lvalp = (unsigned long)val;
1761                 }
1762         }
1763         return 0;
1764 }
1765
1766 /*
1767  *      init may raise the set.
1768  */
1769
1770 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1771                         void __user *buffer, size_t *lenp, loff_t *ppos)
1772 {
1773         int op;
1774
1775         if (write && !capable(CAP_SYS_MODULE)) {
1776                 return -EPERM;
1777         }
1778
1779         op = is_init(current) ? OP_SET : OP_AND;
1780         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1781                                 do_proc_dointvec_bset_conv,&op);
1782 }
1783
1784 /*
1785  *      Taint values can only be increased
1786  */
1787 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1788                                void __user *buffer, size_t *lenp, loff_t *ppos)
1789 {
1790         int op;
1791
1792         if (write && !capable(CAP_SYS_ADMIN))
1793                 return -EPERM;
1794
1795         op = OP_OR;
1796         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1797                                 do_proc_dointvec_bset_conv,&op);
1798 }
1799
1800 struct do_proc_dointvec_minmax_conv_param {
1801         int *min;
1802         int *max;
1803 };
1804
1805 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1806                                         int *valp,
1807                                         int write, void *data)
1808 {
1809         struct do_proc_dointvec_minmax_conv_param *param = data;
1810         if (write) {
1811                 int val = *negp ? -*lvalp : *lvalp;
1812                 if ((param->min && *param->min > val) ||
1813                     (param->max && *param->max < val))
1814                         return -EINVAL;
1815                 *valp = val;
1816         } else {
1817                 int val = *valp;
1818                 if (val < 0) {
1819                         *negp = -1;
1820                         *lvalp = (unsigned long)-val;
1821                 } else {
1822                         *negp = 0;
1823                         *lvalp = (unsigned long)val;
1824                 }
1825         }
1826         return 0;
1827 }
1828
1829 /**
1830  * proc_dointvec_minmax - read a vector of integers with min/max values
1831  * @table: the sysctl table
1832  * @write: %TRUE if this is a write to the sysctl file
1833  * @filp: the file structure
1834  * @buffer: the user buffer
1835  * @lenp: the size of the user buffer
1836  * @ppos: file position
1837  *
1838  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1839  * values from/to the user buffer, treated as an ASCII string.
1840  *
1841  * This routine will ensure the values are within the range specified by
1842  * table->extra1 (min) and table->extra2 (max).
1843  *
1844  * Returns 0 on success.
1845  */
1846 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1847                   void __user *buffer, size_t *lenp, loff_t *ppos)
1848 {
1849         struct do_proc_dointvec_minmax_conv_param param = {
1850                 .min = (int *) table->extra1,
1851                 .max = (int *) table->extra2,
1852         };
1853         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1854                                 do_proc_dointvec_minmax_conv, &param);
1855 }
1856
1857 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1858                                      struct file *filp,
1859                                      void __user *buffer,
1860                                      size_t *lenp, loff_t *ppos,
1861                                      unsigned long convmul,
1862                                      unsigned long convdiv)
1863 {
1864 #define TMPBUFLEN 21
1865         unsigned long *i, *min, *max, val;
1866         int vleft, first=1, neg;
1867         size_t len, left;
1868         char buf[TMPBUFLEN], *p;
1869         char __user *s = buffer;
1870
1871         if (!data || !table->maxlen || !*lenp ||
1872             (*ppos && !write)) {
1873                 *lenp = 0;
1874                 return 0;
1875         }
1876
1877         i = (unsigned long *) data;
1878         min = (unsigned long *) table->extra1;
1879         max = (unsigned long *) table->extra2;
1880         vleft = table->maxlen / sizeof(unsigned long);
1881         left = *lenp;
1882
1883         for (; left && vleft--; i++, min++, max++, first=0) {
1884                 if (write) {
1885                         while (left) {
1886                                 char c;
1887                                 if (get_user(c, s))
1888                                         return -EFAULT;
1889                                 if (!isspace(c))
1890                                         break;
1891                                 left--;
1892                                 s++;
1893                         }
1894                         if (!left)
1895                                 break;
1896                         neg = 0;
1897                         len = left;
1898                         if (len > TMPBUFLEN-1)
1899                                 len = TMPBUFLEN-1;
1900                         if (copy_from_user(buf, s, len))
1901                                 return -EFAULT;
1902                         buf[len] = 0;
1903                         p = buf;
1904                         if (*p == '-' && left > 1) {
1905                                 neg = 1;
1906                                 p++;
1907                         }
1908                         if (*p < '0' || *p > '9')
1909                                 break;
1910                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1911                         len = p-buf;
1912                         if ((len < left) && *p && !isspace(*p))
1913                                 break;
1914                         if (neg)
1915                                 val = -val;
1916                         s += len;
1917                         left -= len;
1918
1919                         if(neg)
1920                                 continue;
1921                         if ((min && val < *min) || (max && val > *max))
1922                                 continue;
1923                         *i = val;
1924                 } else {
1925                         p = buf;
1926                         if (!first)
1927                                 *p++ = '\t';
1928                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1929                         len = strlen(buf);
1930                         if (len > left)
1931                                 len = left;
1932                         if(copy_to_user(s, buf, len))
1933                                 return -EFAULT;
1934                         left -= len;
1935                         s += len;
1936                 }
1937         }
1938
1939         if (!write && !first && left) {
1940                 if(put_user('\n', s))
1941                         return -EFAULT;
1942                 left--, s++;
1943         }
1944         if (write) {
1945                 while (left) {
1946                         char c;
1947                         if (get_user(c, s++))
1948                                 return -EFAULT;
1949                         if (!isspace(c))
1950                                 break;
1951                         left--;
1952                 }
1953         }
1954         if (write && first)
1955                 return -EINVAL;
1956         *lenp -= left;
1957         *ppos += *lenp;
1958         return 0;
1959 #undef TMPBUFLEN
1960 }
1961
1962 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1963                                      struct file *filp,
1964                                      void __user *buffer,
1965                                      size_t *lenp, loff_t *ppos,
1966                                      unsigned long convmul,
1967                                      unsigned long convdiv)
1968 {
1969         return __do_proc_doulongvec_minmax(table->data, table, write,
1970                         filp, buffer, lenp, ppos, convmul, convdiv);
1971 }
1972
1973 /**
1974  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1975  * @table: the sysctl table
1976  * @write: %TRUE if this is a write to the sysctl file
1977  * @filp: the file structure
1978  * @buffer: the user buffer
1979  * @lenp: the size of the user buffer
1980  * @ppos: file position
1981  *
1982  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1983  * values from/to the user buffer, treated as an ASCII string.
1984  *
1985  * This routine will ensure the values are within the range specified by
1986  * table->extra1 (min) and table->extra2 (max).
1987  *
1988  * Returns 0 on success.
1989  */
1990 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
1991                            void __user *buffer, size_t *lenp, loff_t *ppos)
1992 {
1993     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
1994 }
1995
1996 /**
1997  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1998  * @table: the sysctl table
1999  * @write: %TRUE if this is a write to the sysctl file
2000  * @filp: the file structure
2001  * @buffer: the user buffer
2002  * @lenp: the size of the user buffer
2003  * @ppos: file position
2004  *
2005  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2006  * values from/to the user buffer, treated as an ASCII string. The values
2007  * are treated as milliseconds, and converted to jiffies when they are stored.
2008  *
2009  * This routine will ensure the values are within the range specified by
2010  * table->extra1 (min) and table->extra2 (max).
2011  *
2012  * Returns 0 on success.
2013  */
2014 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2015                                       struct file *filp,
2016                                       void __user *buffer,
2017                                       size_t *lenp, loff_t *ppos)
2018 {
2019     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2020                                      lenp, ppos, HZ, 1000l);
2021 }
2022
2023
2024 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2025                                          int *valp,
2026                                          int write, void *data)
2027 {
2028         if (write) {
2029                 if (*lvalp > LONG_MAX / HZ)
2030                         return 1;
2031                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2032         } else {
2033                 int val = *valp;
2034                 unsigned long lval;
2035                 if (val < 0) {
2036                         *negp = -1;
2037                         lval = (unsigned long)-val;
2038                 } else {
2039                         *negp = 0;
2040                         lval = (unsigned long)val;
2041                 }
2042                 *lvalp = lval / HZ;
2043         }
2044         return 0;
2045 }
2046
2047 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2048                                                 int *valp,
2049                                                 int write, void *data)
2050 {
2051         if (write) {
2052                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2053                         return 1;
2054                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2055         } else {
2056                 int val = *valp;
2057                 unsigned long lval;
2058                 if (val < 0) {
2059                         *negp = -1;
2060                         lval = (unsigned long)-val;
2061                 } else {
2062                         *negp = 0;
2063                         lval = (unsigned long)val;
2064                 }
2065                 *lvalp = jiffies_to_clock_t(lval);
2066         }
2067         return 0;
2068 }
2069
2070 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2071                                             int *valp,
2072                                             int write, void *data)
2073 {
2074         if (write) {
2075                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2076         } else {
2077                 int val = *valp;
2078                 unsigned long lval;
2079                 if (val < 0) {
2080                         *negp = -1;
2081                         lval = (unsigned long)-val;
2082                 } else {
2083                         *negp = 0;
2084                         lval = (unsigned long)val;
2085                 }
2086                 *lvalp = jiffies_to_msecs(lval);
2087         }
2088         return 0;
2089 }
2090
2091 /**
2092  * proc_dointvec_jiffies - read a vector of integers as seconds
2093  * @table: the sysctl table
2094  * @write: %TRUE if this is a write to the sysctl file
2095  * @filp: the file structure
2096  * @buffer: the user buffer
2097  * @lenp: the size of the user buffer
2098  * @ppos: file position
2099  *
2100  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2101  * values from/to the user buffer, treated as an ASCII string.
2102  * The values read are assumed to be in seconds, and are converted into
2103  * jiffies.
2104  *
2105  * Returns 0 on success.
2106  */
2107 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2108                           void __user *buffer, size_t *lenp, loff_t *ppos)
2109 {
2110     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2111                             do_proc_dointvec_jiffies_conv,NULL);
2112 }
2113
2114 /**
2115  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2116  * @table: the sysctl table
2117  * @write: %TRUE if this is a write to the sysctl file
2118  * @filp: the file structure
2119  * @buffer: the user buffer
2120  * @lenp: the size of the user buffer
2121  * @ppos: pointer to the file position
2122  *
2123  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2124  * values from/to the user buffer, treated as an ASCII string.
2125  * The values read are assumed to be in 1/USER_HZ seconds, and
2126  * are converted into jiffies.
2127  *
2128  * Returns 0 on success.
2129  */
2130 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2131                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2132 {
2133     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2134                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2135 }
2136
2137 /**
2138  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2139  * @table: the sysctl table
2140  * @write: %TRUE if this is a write to the sysctl file
2141  * @filp: the file structure
2142  * @buffer: the user buffer
2143  * @lenp: the size of the user buffer
2144  * @ppos: file position
2145  * @ppos: the current position in the file
2146  *
2147  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2148  * values from/to the user buffer, treated as an ASCII string.
2149  * The values read are assumed to be in 1/1000 seconds, and
2150  * are converted into jiffies.
2151  *
2152  * Returns 0 on success.
2153  */
2154 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2155                              void __user *buffer, size_t *lenp, loff_t *ppos)
2156 {
2157         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2158                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2159 }
2160
2161 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2162                            void __user *buffer, size_t *lenp, loff_t *ppos)
2163 {
2164         struct pid *new_pid;
2165         pid_t tmp;
2166         int r;
2167
2168         tmp = pid_nr(cad_pid);
2169
2170         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2171                                lenp, ppos, NULL, NULL);
2172         if (r || !write)
2173                 return r;
2174
2175         new_pid = find_get_pid(tmp);
2176         if (!new_pid)
2177                 return -ESRCH;
2178
2179         put_pid(xchg(&cad_pid, new_pid));
2180         return 0;
2181 }
2182
2183 #else /* CONFIG_PROC_FS */
2184
2185 int proc_dostring(ctl_table *table, int write, struct file *filp,
2186                   void __user *buffer, size_t *lenp, loff_t *ppos)
2187 {
2188         return -ENOSYS;
2189 }
2190
2191 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2192                   void __user *buffer, size_t *lenp, loff_t *ppos)
2193 {
2194         return -ENOSYS;
2195 }
2196
2197 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2198                         void __user *buffer, size_t *lenp, loff_t *ppos)
2199 {
2200         return -ENOSYS;
2201 }
2202
2203 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2204                     void __user *buffer, size_t *lenp, loff_t *ppos)
2205 {
2206         return -ENOSYS;
2207 }
2208
2209 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2210                     void __user *buffer, size_t *lenp, loff_t *ppos)
2211 {
2212         return -ENOSYS;
2213 }
2214
2215 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2216                     void __user *buffer, size_t *lenp, loff_t *ppos)
2217 {
2218         return -ENOSYS;
2219 }
2220
2221 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2222                              void __user *buffer, size_t *lenp, loff_t *ppos)
2223 {
2224         return -ENOSYS;
2225 }
2226
2227 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2228                     void __user *buffer, size_t *lenp, loff_t *ppos)
2229 {
2230         return -ENOSYS;
2231 }
2232
2233 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2234                                       struct file *filp,
2235                                       void __user *buffer,
2236                                       size_t *lenp, loff_t *ppos)
2237 {
2238     return -ENOSYS;
2239 }
2240
2241
2242 #endif /* CONFIG_PROC_FS */
2243
2244
2245 #ifdef CONFIG_SYSCTL_SYSCALL
2246 /*
2247  * General sysctl support routines
2248  */
2249
2250 /* The generic string strategy routine: */
2251 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2252                   void __user *oldval, size_t __user *oldlenp,
2253                   void __user *newval, size_t newlen)
2254 {
2255         if (!table->data || !table->maxlen)
2256                 return -ENOTDIR;
2257
2258         if (oldval && oldlenp) {
2259                 size_t bufsize;
2260                 if (get_user(bufsize, oldlenp))
2261                         return -EFAULT;
2262                 if (bufsize) {
2263                         size_t len = strlen(table->data), copied;
2264
2265                         /* This shouldn't trigger for a well-formed sysctl */
2266                         if (len > table->maxlen)
2267                                 len = table->maxlen;
2268
2269                         /* Copy up to a max of bufsize-1 bytes of the string */
2270                         copied = (len >= bufsize) ? bufsize - 1 : len;
2271
2272                         if (copy_to_user(oldval, table->data, copied) ||
2273                             put_user(0, (char __user *)(oldval + copied)))
2274                                 return -EFAULT;
2275                         if (put_user(len, oldlenp))
2276                                 return -EFAULT;
2277                 }
2278         }
2279         if (newval && newlen) {
2280                 size_t len = newlen;
2281                 if (len > table->maxlen)
2282                         len = table->maxlen;
2283                 if(copy_from_user(table->data, newval, len))
2284                         return -EFAULT;
2285                 if (len == table->maxlen)
2286                         len--;
2287                 ((char *) table->data)[len] = 0;
2288         }
2289         return 1;
2290 }
2291
2292 /*
2293  * This function makes sure that all of the integers in the vector
2294  * are between the minimum and maximum values given in the arrays
2295  * table->extra1 and table->extra2, respectively.
2296  */
2297 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2298                 void __user *oldval, size_t __user *oldlenp,
2299                 void __user *newval, size_t newlen)
2300 {
2301
2302         if (newval && newlen) {
2303                 int __user *vec = (int __user *) newval;
2304                 int *min = (int *) table->extra1;
2305                 int *max = (int *) table->extra2;
2306                 size_t length;
2307                 int i;
2308
2309                 if (newlen % sizeof(int) != 0)
2310                         return -EINVAL;
2311
2312                 if (!table->extra1 && !table->extra2)
2313                         return 0;
2314
2315                 if (newlen > table->maxlen)
2316                         newlen = table->maxlen;
2317                 length = newlen / sizeof(int);
2318
2319                 for (i = 0; i < length; i++) {
2320                         int value;
2321                         if (get_user(value, vec + i))
2322                                 return -EFAULT;
2323                         if (min && value < min[i])
2324                                 return -EINVAL;
2325                         if (max && value > max[i])
2326                                 return -EINVAL;
2327                 }
2328         }
2329         return 0;
2330 }
2331
2332 /* Strategy function to convert jiffies to seconds */
2333 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2334                 void __user *oldval, size_t __user *oldlenp,
2335                 void __user *newval, size_t newlen)
2336 {
2337         if (oldval && oldlenp) {
2338                 size_t olen;
2339
2340                 if (get_user(olen, oldlenp))
2341                         return -EFAULT;
2342                 if (olen) {
2343                         int val;
2344
2345                         if (olen < sizeof(int))
2346                                 return -EINVAL;
2347
2348                         val = *(int *)(table->data) / HZ;
2349                         if (put_user(val, (int __user *)oldval))
2350                                 return -EFAULT;
2351                         if (put_user(sizeof(int), oldlenp))
2352                                 return -EFAULT;
2353                 }
2354         }
2355         if (newval && newlen) {
2356                 int new;
2357                 if (newlen != sizeof(int))
2358                         return -EINVAL;
2359                 if (get_user(new, (int __user *)newval))
2360                         return -EFAULT;
2361                 *(int *)(table->data) = new*HZ;
2362         }
2363         return 1;
2364 }
2365
2366 /* Strategy function to convert jiffies to seconds */
2367 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2368                 void __user *oldval, size_t __user *oldlenp,
2369                 void __user *newval, size_t newlen)
2370 {
2371         if (oldval && oldlenp) {
2372                 size_t olen;
2373
2374                 if (get_user(olen, oldlenp))
2375                         return -EFAULT;
2376                 if (olen) {
2377                         int val;
2378
2379                         if (olen < sizeof(int))
2380                                 return -EINVAL;
2381
2382                         val = jiffies_to_msecs(*(int *)(table->data));
2383                         if (put_user(val, (int __user *)oldval))
2384                                 return -EFAULT;
2385                         if (put_user(sizeof(int), oldlenp))
2386                                 return -EFAULT;
2387                 }
2388         }
2389         if (newval && newlen) {
2390                 int new;
2391                 if (newlen != sizeof(int))
2392                         return -EINVAL;
2393                 if (get_user(new, (int __user *)newval))
2394                         return -EFAULT;
2395                 *(int *)(table->data) = msecs_to_jiffies(new);
2396         }
2397         return 1;
2398 }
2399
2400
2401
2402 #else /* CONFIG_SYSCTL_SYSCALL */
2403
2404
2405 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2406 {
2407         static int msg_count;
2408         struct __sysctl_args tmp;
2409         int name[CTL_MAXNAME];
2410         int i;
2411
2412         /* Read in the sysctl name for better debug message logging */
2413         if (copy_from_user(&tmp, args, sizeof(tmp)))
2414                 return -EFAULT;
2415         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2416                 return -ENOTDIR;
2417         for (i = 0; i < tmp.nlen; i++)
2418                 if (get_user(name[i], tmp.name + i))
2419                         return -EFAULT;
2420
2421         /* Ignore accesses to kernel.version */
2422         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2423                 goto out;
2424
2425         if (msg_count < 5) {
2426                 msg_count++;
2427                 printk(KERN_INFO
2428                         "warning: process `%s' used the removed sysctl "
2429                         "system call with ", current->comm);
2430                 for (i = 0; i < tmp.nlen; i++)
2431                         printk("%d.", name[i]);
2432                 printk("\n");
2433         }
2434 out:
2435         return -ENOSYS;
2436 }
2437
2438 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2439                   void __user *oldval, size_t __user *oldlenp,
2440                   void __user *newval, size_t newlen)
2441 {
2442         return -ENOSYS;
2443 }
2444
2445 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2446                 void __user *oldval, size_t __user *oldlenp,
2447                 void __user *newval, size_t newlen)
2448 {
2449         return -ENOSYS;
2450 }
2451
2452 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2453                 void __user *oldval, size_t __user *oldlenp,
2454                 void __user *newval, size_t newlen)
2455 {
2456         return -ENOSYS;
2457 }
2458
2459 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2460                 void __user *oldval, size_t __user *oldlenp,
2461                 void __user *newval, size_t newlen)
2462 {
2463         return -ENOSYS;
2464 }
2465
2466 #endif /* CONFIG_SYSCTL_SYSCALL */
2467
2468 /*
2469  * No sense putting this after each symbol definition, twice,
2470  * exception granted :-)
2471  */
2472 EXPORT_SYMBOL(proc_dointvec);
2473 EXPORT_SYMBOL(proc_dointvec_jiffies);
2474 EXPORT_SYMBOL(proc_dointvec_minmax);
2475 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2476 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2477 EXPORT_SYMBOL(proc_dostring);
2478 EXPORT_SYMBOL(proc_doulongvec_minmax);
2479 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2480 EXPORT_SYMBOL(register_sysctl_table);
2481 EXPORT_SYMBOL(sysctl_intvec);
2482 EXPORT_SYMBOL(sysctl_jiffies);
2483 EXPORT_SYMBOL(sysctl_ms_jiffies);
2484 EXPORT_SYMBOL(sysctl_string);
2485 EXPORT_SYMBOL(unregister_sysctl_table);