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

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/config.h>
  22 #include <linux/module.h>
  23 #include <linux/mm.h>
  24 #include <linux/swap.h>
  25 #include <linux/slab.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/capability.h>
  29 #include <linux/ctype.h>
  30 #include <linux/utsname.h>
  31 #include <linux/capability.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/security.h>
  42 #include <linux/initrd.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49
  50 #include <asm/uaccess.h>
  51 #include <asm/processor.h>
  52
  53 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
  54                      void __user *buffer, size_t *lenp, loff_t *ppos);
  55
  56 #if defined(CONFIG_SYSCTL)
  57
  58 /* External variables not in a header file. */
  59 extern int C_A_D;
  60 extern int sysctl_overcommit_memory;
  61 extern int sysctl_overcommit_ratio;
  62 extern int max_threads;
  63 extern int sysrq_enabled;
  64 extern int core_uses_pid;
  65 extern int suid_dumpable;
  66 extern char core_pattern[];
  67 extern int cad_pid;
  68 extern int pid_max;
  69 extern int min_free_kbytes;
  70 extern int printk_ratelimit_jiffies;
  71 extern int printk_ratelimit_burst;
  72 extern int pid_max_min, pid_max_max;
  73 extern int sysctl_drop_caches;
  74 extern int percpu_pagelist_fraction;
  75
  76 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
  77 int unknown_nmi_panic;
  78 extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *,
  79                                   void __user *, size_t *, loff_t *);
  80 #endif
  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 #ifdef CONFIG_SYSVIPC
  96 extern size_t shm_ctlmax;
  97 extern size_t shm_ctlall;
  98 extern int shm_ctlmni;
  99 extern int msg_ctlmax;
 100 extern int msg_ctlmnb;
 101 extern int msg_ctlmni;
 102 extern int sem_ctls[];
 103 #endif
 104
 105 #ifdef __sparc__
 106 extern char reboot_command [];
 107 extern int stop_a_enabled;
 108 extern int scons_pwroff;
 109 #endif
 110
 111 #ifdef __hppa__
 112 extern int pwrsw_enabled;
 113 extern int unaligned_enabled;
 114 #endif
 115
 116 #ifdef CONFIG_S390
 117 #ifdef CONFIG_MATHEMU
 118 extern int sysctl_ieee_emulation_warnings;
 119 #endif
 120 extern int sysctl_userprocess_debug;
 121 extern int spin_retry;
 122 #endif
 123
 124 extern int sysctl_hz_timer;
 125
 126 #ifdef CONFIG_BSD_PROCESS_ACCT
 127 extern int acct_parm[];
 128 #endif
 129
 130 #ifdef CONFIG_IA64
 131 extern int no_unaligned_warning;
 132 #endif
 133
 134 static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
 135                        ctl_table *, void **);
 136 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
 137                   void __user *buffer, size_t *lenp, loff_t *ppos);
 138
 139 static ctl_table root_table[];
 140 static struct ctl_table_header root_table_header =
 141         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 142
 143 static ctl_table kern_table[];
 144 static ctl_table vm_table[];
 145 static ctl_table proc_table[];
 146 static ctl_table fs_table[];
 147 static ctl_table debug_table[];
 148 static ctl_table dev_table[];
 149 extern ctl_table random_table[];
 150 #ifdef CONFIG_UNIX98_PTYS
 151 extern ctl_table pty_table[];
 152 #endif
 153 #ifdef CONFIG_INOTIFY
 154 extern ctl_table inotify_table[];
 155 #endif
 156
 157 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 158 int sysctl_legacy_va_layout;
 159 #endif
 160
 161 /* /proc declarations: */
 162
 163 #ifdef CONFIG_PROC_FS
 164
 165 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
 166 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
 167 static int proc_opensys(struct inode *, struct file *);
 168
 169 struct file_operations proc_sys_file_operations = {
 170         .open           = proc_opensys,
 171         .read           = proc_readsys,
 172         .write          = proc_writesys,
 173 };
 174
 175 extern struct proc_dir_entry *proc_sys_root;
 176
 177 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
 178 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
 179 #endif
 180
 181 /* The default sysctl tables: */
 182
 183 static ctl_table root_table[] = {
 184         {
 185                 .ctl_name       = CTL_KERN,
 186                 .procname       = "kernel",
 187                 .mode           = 0555,
 188                 .child          = kern_table,
 189         },
 190         {
 191                 .ctl_name       = CTL_VM,
 192                 .procname       = "vm",
 193                 .mode           = 0555,
 194                 .child          = vm_table,
 195         },
 196 #ifdef CONFIG_NET
 197         {
 198                 .ctl_name       = CTL_NET,
 199                 .procname       = "net",
 200                 .mode           = 0555,
 201                 .child          = net_table,
 202         },
 203 #endif
 204         {
 205                 .ctl_name       = CTL_PROC,
 206                 .procname       = "proc",
 207                 .mode           = 0555,
 208                 .child          = proc_table,
 209         },
 210         {
 211                 .ctl_name       = CTL_FS,
 212                 .procname       = "fs",
 213                 .mode           = 0555,
 214                 .child          = fs_table,
 215         },
 216         {
 217                 .ctl_name       = CTL_DEBUG,
 218                 .procname       = "debug",
 219                 .mode           = 0555,
 220                 .child          = debug_table,
 221         },
 222         {
 223                 .ctl_name       = CTL_DEV,
 224                 .procname       = "dev",
 225                 .mode           = 0555,
 226                 .child          = dev_table,
 227         },
 228
 229         { .ctl_name = 0 }
 230 };
 231
 232 static ctl_table kern_table[] = {
 233         {
 234                 .ctl_name       = KERN_OSTYPE,
 235                 .procname       = "ostype",
 236                 .data           = system_utsname.sysname,
 237                 .maxlen         = sizeof(system_utsname.sysname),
 238                 .mode           = 0444,
 239                 .proc_handler   = &proc_doutsstring,
 240                 .strategy       = &sysctl_string,
 241         },
 242         {
 243                 .ctl_name       = KERN_OSRELEASE,
 244                 .procname       = "osrelease",
 245                 .data           = system_utsname.release,
 246                 .maxlen         = sizeof(system_utsname.release),
 247                 .mode           = 0444,
 248                 .proc_handler   = &proc_doutsstring,
 249                 .strategy       = &sysctl_string,
 250         },
 251         {
 252                 .ctl_name       = KERN_VERSION,
 253                 .procname       = "version",
 254                 .data           = system_utsname.version,
 255                 .maxlen         = sizeof(system_utsname.version),
 256                 .mode           = 0444,
 257                 .proc_handler   = &proc_doutsstring,
 258                 .strategy       = &sysctl_string,
 259         },
 260         {
 261                 .ctl_name       = KERN_NODENAME,
 262                 .procname       = "hostname",
 263                 .data           = system_utsname.nodename,
 264                 .maxlen         = sizeof(system_utsname.nodename),
 265                 .mode           = 0644,
 266                 .proc_handler   = &proc_doutsstring,
 267                 .strategy       = &sysctl_string,
 268         },
 269         {
 270                 .ctl_name       = KERN_DOMAINNAME,
 271                 .procname       = "domainname",
 272                 .data           = system_utsname.domainname,
 273                 .maxlen         = sizeof(system_utsname.domainname),
 274                 .mode           = 0644,
 275                 .proc_handler   = &proc_doutsstring,
 276                 .strategy       = &sysctl_string,
 277         },
 278         {
 279                 .ctl_name       = KERN_PANIC,
 280                 .procname       = "panic",
 281                 .data           = &panic_timeout,
 282                 .maxlen         = sizeof(int),
 283                 .mode           = 0644,
 284                 .proc_handler   = &proc_dointvec,
 285         },
 286         {
 287                 .ctl_name       = KERN_CORE_USES_PID,
 288                 .procname       = "core_uses_pid",
 289                 .data           = &core_uses_pid,
 290                 .maxlen         = sizeof(int),
 291                 .mode           = 0644,
 292                 .proc_handler   = &proc_dointvec,
 293         },
 294         {
 295                 .ctl_name       = KERN_CORE_PATTERN,
 296                 .procname       = "core_pattern",
 297                 .data           = core_pattern,
 298                 .maxlen         = 64,
 299                 .mode           = 0644,
 300                 .proc_handler   = &proc_dostring,
 301                 .strategy       = &sysctl_string,
 302         },
 303         {
 304                 .ctl_name       = KERN_TAINTED,
 305                 .procname       = "tainted",
 306                 .data           = &tainted,
 307                 .maxlen         = sizeof(int),
 308                 .mode           = 0444,
 309                 .proc_handler   = &proc_dointvec,
 310         },
 311         {
 312                 .ctl_name       = KERN_CAP_BSET,
 313                 .procname       = "cap-bound",
 314                 .data           = &cap_bset,
 315                 .maxlen         = sizeof(kernel_cap_t),
 316                 .mode           = 0600,
 317                 .proc_handler   = &proc_dointvec_bset,
 318         },
 319 #ifdef CONFIG_BLK_DEV_INITRD
 320         {
 321                 .ctl_name       = KERN_REALROOTDEV,
 322                 .procname       = "real-root-dev",
 323                 .data           = &real_root_dev,
 324                 .maxlen         = sizeof(int),
 325                 .mode           = 0644,
 326                 .proc_handler   = &proc_dointvec,
 327         },
 328 #endif
 329 #ifdef __sparc__
 330         {
 331                 .ctl_name       = KERN_SPARC_REBOOT,
 332                 .procname       = "reboot-cmd",
 333                 .data           = reboot_command,
 334                 .maxlen         = 256,
 335                 .mode           = 0644,
 336                 .proc_handler   = &proc_dostring,
 337                 .strategy       = &sysctl_string,
 338         },
 339         {
 340                 .ctl_name       = KERN_SPARC_STOP_A,
 341                 .procname       = "stop-a",
 342                 .data           = &stop_a_enabled,
 343                 .maxlen         = sizeof (int),
 344                 .mode           = 0644,
 345                 .proc_handler   = &proc_dointvec,
 346         },
 347         {
 348                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 349                 .procname       = "scons-poweroff",
 350                 .data           = &scons_pwroff,
 351                 .maxlen         = sizeof (int),
 352                 .mode           = 0644,
 353                 .proc_handler   = &proc_dointvec,
 354         },
 355 #endif
 356 #ifdef __hppa__
 357         {
 358                 .ctl_name       = KERN_HPPA_PWRSW,
 359                 .procname       = "soft-power",
 360                 .data           = &pwrsw_enabled,
 361                 .maxlen         = sizeof (int),
 362                 .mode           = 0644,
 363                 .proc_handler   = &proc_dointvec,
 364         },
 365         {
 366                 .ctl_name       = KERN_HPPA_UNALIGNED,
 367                 .procname       = "unaligned-trap",
 368                 .data           = &unaligned_enabled,
 369                 .maxlen         = sizeof (int),
 370                 .mode           = 0644,
 371                 .proc_handler   = &proc_dointvec,
 372         },
 373 #endif
 374         {
 375                 .ctl_name       = KERN_CTLALTDEL,
 376                 .procname       = "ctrl-alt-del",
 377                 .data           = &C_A_D,
 378                 .maxlen         = sizeof(int),
 379                 .mode           = 0644,
 380                 .proc_handler   = &proc_dointvec,
 381         },
 382         {
 383                 .ctl_name       = KERN_PRINTK,
 384                 .procname       = "printk",
 385                 .data           = &console_loglevel,
 386                 .maxlen         = 4*sizeof(int),
 387                 .mode           = 0644,
 388                 .proc_handler   = &proc_dointvec,
 389         },
 390 #ifdef CONFIG_KMOD
 391         {
 392                 .ctl_name       = KERN_MODPROBE,
 393                 .procname       = "modprobe",
 394                 .data           = &modprobe_path,
 395                 .maxlen         = KMOD_PATH_LEN,
 396                 .mode           = 0644,
 397                 .proc_handler   = &proc_dostring,
 398                 .strategy       = &sysctl_string,
 399         },
 400 #endif
 401 #ifdef CONFIG_HOTPLUG
 402         {
 403                 .ctl_name       = KERN_HOTPLUG,
 404                 .procname       = "hotplug",
 405                 .data           = &uevent_helper,
 406                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 407                 .mode           = 0644,
 408                 .proc_handler   = &proc_dostring,
 409                 .strategy       = &sysctl_string,
 410         },
 411 #endif
 412 #ifdef CONFIG_CHR_DEV_SG
 413         {
 414                 .ctl_name       = KERN_SG_BIG_BUFF,
 415                 .procname       = "sg-big-buff",
 416                 .data           = &sg_big_buff,
 417                 .maxlen         = sizeof (int),
 418                 .mode           = 0444,
 419                 .proc_handler   = &proc_dointvec,
 420         },
 421 #endif
 422 #ifdef CONFIG_BSD_PROCESS_ACCT
 423         {
 424                 .ctl_name       = KERN_ACCT,
 425                 .procname       = "acct",
 426                 .data           = &acct_parm,
 427                 .maxlen         = 3*sizeof(int),
 428                 .mode           = 0644,
 429                 .proc_handler   = &proc_dointvec,
 430         },
 431 #endif
 432 #ifdef CONFIG_SYSVIPC
 433         {
 434                 .ctl_name       = KERN_SHMMAX,
 435                 .procname       = "shmmax",
 436                 .data           = &shm_ctlmax,
 437                 .maxlen         = sizeof (size_t),
 438                 .mode           = 0644,
 439                 .proc_handler   = &proc_doulongvec_minmax,
 440         },
 441         {
 442                 .ctl_name       = KERN_SHMALL,
 443                 .procname       = "shmall",
 444                 .data           = &shm_ctlall,
 445                 .maxlen         = sizeof (size_t),
 446                 .mode           = 0644,
 447                 .proc_handler   = &proc_doulongvec_minmax,
 448         },
 449         {
 450                 .ctl_name       = KERN_SHMMNI,
 451                 .procname       = "shmmni",
 452                 .data           = &shm_ctlmni,
 453                 .maxlen         = sizeof (int),
 454                 .mode           = 0644,
 455                 .proc_handler   = &proc_dointvec,
 456         },
 457         {
 458                 .ctl_name       = KERN_MSGMAX,
 459                 .procname       = "msgmax",
 460                 .data           = &msg_ctlmax,
 461                 .maxlen         = sizeof (int),
 462                 .mode           = 0644,
 463                 .proc_handler   = &proc_dointvec,
 464         },
 465         {
 466                 .ctl_name       = KERN_MSGMNI,
 467                 .procname       = "msgmni",
 468                 .data           = &msg_ctlmni,
 469                 .maxlen         = sizeof (int),
 470                 .mode           = 0644,
 471                 .proc_handler   = &proc_dointvec,
 472         },
 473         {
 474                 .ctl_name       = KERN_MSGMNB,
 475                 .procname       =  "msgmnb",
 476                 .data           = &msg_ctlmnb,
 477                 .maxlen         = sizeof (int),
 478                 .mode           = 0644,
 479                 .proc_handler   = &proc_dointvec,
 480         },
 481         {
 482                 .ctl_name       = KERN_SEM,
 483                 .procname       = "sem",
 484                 .data           = &sem_ctls,
 485                 .maxlen         = 4*sizeof (int),
 486                 .mode           = 0644,
 487                 .proc_handler   = &proc_dointvec,
 488         },
 489 #endif
 490 #ifdef CONFIG_MAGIC_SYSRQ
 491         {
 492                 .ctl_name       = KERN_SYSRQ,
 493                 .procname       = "sysrq",
 494                 .data           = &sysrq_enabled,
 495                 .maxlen         = sizeof (int),
 496                 .mode           = 0644,
 497                 .proc_handler   = &proc_dointvec,
 498         },
 499 #endif
 500         {
 501                 .ctl_name       = KERN_CADPID,
 502                 .procname       = "cad_pid",
 503                 .data           = &cad_pid,
 504                 .maxlen         = sizeof (int),
 505                 .mode           = 0600,
 506                 .proc_handler   = &proc_dointvec,
 507         },
 508         {
 509                 .ctl_name       = KERN_MAX_THREADS,
 510                 .procname       = "threads-max",
 511                 .data           = &max_threads,
 512                 .maxlen         = sizeof(int),
 513                 .mode           = 0644,
 514                 .proc_handler   = &proc_dointvec,
 515         },
 516         {
 517                 .ctl_name       = KERN_RANDOM,
 518                 .procname       = "random",
 519                 .mode           = 0555,
 520                 .child          = random_table,
 521         },
 522 #ifdef CONFIG_UNIX98_PTYS
 523         {
 524                 .ctl_name       = KERN_PTY,
 525                 .procname       = "pty",
 526                 .mode           = 0555,
 527                 .child          = pty_table,
 528         },
 529 #endif
 530         {
 531                 .ctl_name       = KERN_OVERFLOWUID,
 532                 .procname       = "overflowuid",
 533                 .data           = &overflowuid,
 534                 .maxlen         = sizeof(int),
 535                 .mode           = 0644,
 536                 .proc_handler   = &proc_dointvec_minmax,
 537                 .strategy       = &sysctl_intvec,
 538                 .extra1         = &minolduid,
 539                 .extra2         = &maxolduid,
 540         },
 541         {
 542                 .ctl_name       = KERN_OVERFLOWGID,
 543                 .procname       = "overflowgid",
 544                 .data           = &overflowgid,
 545                 .maxlen         = sizeof(int),
 546                 .mode           = 0644,
 547                 .proc_handler   = &proc_dointvec_minmax,
 548                 .strategy       = &sysctl_intvec,
 549                 .extra1         = &minolduid,
 550                 .extra2         = &maxolduid,
 551         },
 552 #ifdef CONFIG_S390
 553 #ifdef CONFIG_MATHEMU
 554         {
 555                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 556                 .procname       = "ieee_emulation_warnings",
 557                 .data           = &sysctl_ieee_emulation_warnings,
 558                 .maxlen         = sizeof(int),
 559                 .mode           = 0644,
 560                 .proc_handler   = &proc_dointvec,
 561         },
 562 #endif
 563 #ifdef CONFIG_NO_IDLE_HZ
 564         {
 565                 .ctl_name       = KERN_HZ_TIMER,
 566                 .procname       = "hz_timer",
 567                 .data           = &sysctl_hz_timer,
 568                 .maxlen         = sizeof(int),
 569                 .mode           = 0644,
 570                 .proc_handler   = &proc_dointvec,
 571         },
 572 #endif
 573         {
 574                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 575                 .procname       = "userprocess_debug",
 576                 .data           = &sysctl_userprocess_debug,
 577                 .maxlen         = sizeof(int),
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dointvec,
 580         },
 581 #endif
 582         {
 583                 .ctl_name       = KERN_PIDMAX,
 584                 .procname       = "pid_max",
 585                 .data           = &pid_max,
 586                 .maxlen         = sizeof (int),
 587                 .mode           = 0644,
 588                 .proc_handler   = &proc_dointvec_minmax,
 589                 .strategy       = sysctl_intvec,
 590                 .extra1         = &pid_max_min,
 591                 .extra2         = &pid_max_max,
 592         },
 593         {
 594                 .ctl_name       = KERN_PANIC_ON_OOPS,
 595                 .procname       = "panic_on_oops",
 596                 .data           = &panic_on_oops,
 597                 .maxlen         = sizeof(int),
 598                 .mode           = 0644,
 599                 .proc_handler   = &proc_dointvec,
 600         },
 601         {
 602                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 603                 .procname       = "printk_ratelimit",
 604                 .data           = &printk_ratelimit_jiffies,
 605                 .maxlen         = sizeof(int),
 606                 .mode           = 0644,
 607                 .proc_handler   = &proc_dointvec_jiffies,
 608                 .strategy       = &sysctl_jiffies,
 609         },
 610         {
 611                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 612                 .procname       = "printk_ratelimit_burst",
 613                 .data           = &printk_ratelimit_burst,
 614                 .maxlen         = sizeof(int),
 615                 .mode           = 0644,
 616                 .proc_handler   = &proc_dointvec,
 617         },
 618         {
 619                 .ctl_name       = KERN_NGROUPS_MAX,
 620                 .procname       = "ngroups_max",
 621                 .data           = &ngroups_max,
 622                 .maxlen         = sizeof (int),
 623                 .mode           = 0444,
 624                 .proc_handler   = &proc_dointvec,
 625         },
 626 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 627         {
 628                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 629                 .procname       = "unknown_nmi_panic",
 630                 .data           = &unknown_nmi_panic,
 631                 .maxlen         = sizeof (int),
 632                 .mode           = 0644,
 633                 .proc_handler   = &proc_unknown_nmi_panic,
 634         },
 635 #endif
 636 #if defined(CONFIG_X86)
 637         {
 638                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 639                 .procname       = "bootloader_type",
 640                 .data           = &bootloader_type,
 641                 .maxlen         = sizeof (int),
 642                 .mode           = 0444,
 643                 .proc_handler   = &proc_dointvec,
 644         },
 645 #endif
 646 #if defined(CONFIG_MMU)
 647         {
 648                 .ctl_name       = KERN_RANDOMIZE,
 649                 .procname       = "randomize_va_space",
 650                 .data           = &randomize_va_space,
 651                 .maxlen         = sizeof(int),
 652                 .mode           = 0644,
 653                 .proc_handler   = &proc_dointvec,
 654         },
 655 #endif
 656 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 657         {
 658                 .ctl_name       = KERN_SPIN_RETRY,
 659                 .procname       = "spin_retry",
 660                 .data           = &spin_retry,
 661                 .maxlen         = sizeof (int),
 662                 .mode           = 0644,
 663                 .proc_handler   = &proc_dointvec,
 664         },
 665 #endif
 666 #ifdef CONFIG_ACPI_SLEEP
 667         {
 668                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 669                 .procname       = "acpi_video_flags",
 670                 .data           = &acpi_video_flags,
 671                 .maxlen         = sizeof (unsigned long),
 672                 .mode           = 0644,
 673                 .proc_handler   = &proc_doulongvec_minmax,
 674         },
 675 #endif
 676 #ifdef CONFIG_IA64
 677         {
 678                 .ctl_name       = KERN_IA64_UNALIGNED,
 679                 .procname       = "ignore-unaligned-usertrap",
 680                 .data           = &no_unaligned_warning,
 681                 .maxlen         = sizeof (int),
 682                 .mode           = 0644,
 683                 .proc_handler   = &proc_dointvec,
 684         },
 685 #endif
 686         { .ctl_name = 0 }
 687 };
 688
 689 /* Constants for minimum and maximum testing in vm_table.
 690    We use these as one-element integer vectors. */
 691 static int zero;
 692 static int one_hundred = 100;
 693
 694
 695 static ctl_table vm_table[] = {
 696         {
 697                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 698                 .procname       = "overcommit_memory",
 699                 .data           = &sysctl_overcommit_memory,
 700                 .maxlen         = sizeof(sysctl_overcommit_memory),
 701                 .mode           = 0644,
 702                 .proc_handler   = &proc_dointvec,
 703         },
 704         {
 705                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 706                 .procname       = "overcommit_ratio",
 707                 .data           = &sysctl_overcommit_ratio,
 708                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 709                 .mode           = 0644,
 710                 .proc_handler   = &proc_dointvec,
 711         },
 712         {
 713                 .ctl_name       = VM_PAGE_CLUSTER,
 714                 .procname       = "page-cluster",
 715                 .data           = &page_cluster,
 716                 .maxlen         = sizeof(int),
 717                 .mode           = 0644,
 718                 .proc_handler   = &proc_dointvec,
 719         },
 720         {
 721                 .ctl_name       = VM_DIRTY_BACKGROUND,
 722                 .procname       = "dirty_background_ratio",
 723                 .data           = &dirty_background_ratio,
 724                 .maxlen         = sizeof(dirty_background_ratio),
 725                 .mode           = 0644,
 726                 .proc_handler   = &proc_dointvec_minmax,
 727                 .strategy       = &sysctl_intvec,
 728                 .extra1         = &zero,
 729                 .extra2         = &one_hundred,
 730         },
 731         {
 732                 .ctl_name       = VM_DIRTY_RATIO,
 733                 .procname       = "dirty_ratio",
 734                 .data           = &vm_dirty_ratio,
 735                 .maxlen         = sizeof(vm_dirty_ratio),
 736                 .mode           = 0644,
 737                 .proc_handler   = &proc_dointvec_minmax,
 738                 .strategy       = &sysctl_intvec,
 739                 .extra1         = &zero,
 740                 .extra2         = &one_hundred,
 741         },
 742         {
 743                 .ctl_name       = VM_DIRTY_WB_CS,
 744                 .procname       = "dirty_writeback_centisecs",
 745                 .data           = &dirty_writeback_interval,
 746                 .maxlen         = sizeof(dirty_writeback_interval),
 747                 .mode           = 0644,
 748                 .proc_handler   = &dirty_writeback_centisecs_handler,
 749         },
 750         {
 751                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 752                 .procname       = "dirty_expire_centisecs",
 753                 .data           = &dirty_expire_interval,
 754                 .maxlen         = sizeof(dirty_expire_interval),
 755                 .mode           = 0644,
 756                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 757         },
 758         {
 759                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 760                 .procname       = "nr_pdflush_threads",
 761                 .data           = &nr_pdflush_threads,
 762                 .maxlen         = sizeof nr_pdflush_threads,
 763                 .mode           = 0444 /* read-only*/,
 764                 .proc_handler   = &proc_dointvec,
 765         },
 766         {
 767                 .ctl_name       = VM_SWAPPINESS,
 768                 .procname       = "swappiness",
 769                 .data           = &vm_swappiness,
 770                 .maxlen         = sizeof(vm_swappiness),
 771                 .mode           = 0644,
 772                 .proc_handler   = &proc_dointvec_minmax,
 773                 .strategy       = &sysctl_intvec,
 774                 .extra1         = &zero,
 775                 .extra2         = &one_hundred,
 776         },
 777 #ifdef CONFIG_HUGETLB_PAGE
 778          {
 779                 .ctl_name       = VM_HUGETLB_PAGES,
 780                 .procname       = "nr_hugepages",
 781                 .data           = &max_huge_pages,
 782                 .maxlen         = sizeof(unsigned long),
 783                 .mode           = 0644,
 784                 .proc_handler   = &hugetlb_sysctl_handler,
 785                 .extra1         = (void *)&hugetlb_zero,
 786                 .extra2         = (void *)&hugetlb_infinity,
 787          },
 788          {
 789                 .ctl_name       = VM_HUGETLB_GROUP,
 790                 .procname       = "hugetlb_shm_group",
 791                 .data           = &sysctl_hugetlb_shm_group,
 792                 .maxlen         = sizeof(gid_t),
 793                 .mode           = 0644,
 794                 .proc_handler   = &proc_dointvec,
 795          },
 796 #endif
 797         {
 798                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 799                 .procname       = "lowmem_reserve_ratio",
 800                 .data           = &sysctl_lowmem_reserve_ratio,
 801                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 802                 .mode           = 0644,
 803                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 804                 .strategy       = &sysctl_intvec,
 805         },
 806         {
 807                 .ctl_name       = VM_DROP_PAGECACHE,
 808                 .procname       = "drop_caches",
 809                 .data           = &sysctl_drop_caches,
 810                 .maxlen         = sizeof(int),
 811                 .mode           = 0644,
 812                 .proc_handler   = drop_caches_sysctl_handler,
 813                 .strategy       = &sysctl_intvec,
 814         },
 815         {
 816                 .ctl_name       = VM_MIN_FREE_KBYTES,
 817                 .procname       = "min_free_kbytes",
 818                 .data           = &min_free_kbytes,
 819                 .maxlen         = sizeof(min_free_kbytes),
 820                 .mode           = 0644,
 821                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 822                 .strategy       = &sysctl_intvec,
 823                 .extra1         = &zero,
 824         },
 825         {
 826                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 827                 .procname       = "percpu_pagelist_fraction",
 828                 .data           = &percpu_pagelist_fraction,
 829                 .maxlen         = sizeof(percpu_pagelist_fraction),
 830                 .mode           = 0644,
 831                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 832                 .strategy       = &sysctl_intvec,
 833                 .extra1         = &min_percpu_pagelist_fract,
 834         },
 835 #ifdef CONFIG_MMU
 836         {
 837                 .ctl_name       = VM_MAX_MAP_COUNT,
 838                 .procname       = "max_map_count",
 839                 .data           = &sysctl_max_map_count,
 840                 .maxlen         = sizeof(sysctl_max_map_count),
 841                 .mode           = 0644,
 842                 .proc_handler   = &proc_dointvec
 843         },
 844 #endif
 845         {
 846                 .ctl_name       = VM_LAPTOP_MODE,
 847                 .procname       = "laptop_mode",
 848                 .data           = &laptop_mode,
 849                 .maxlen         = sizeof(laptop_mode),
 850                 .mode           = 0644,
 851                 .proc_handler   = &proc_dointvec_jiffies,
 852                 .strategy       = &sysctl_jiffies,
 853         },
 854         {
 855                 .ctl_name       = VM_BLOCK_DUMP,
 856                 .procname       = "block_dump",
 857                 .data           = &block_dump,
 858                 .maxlen         = sizeof(block_dump),
 859                 .mode           = 0644,
 860                 .proc_handler   = &proc_dointvec,
 861                 .strategy       = &sysctl_intvec,
 862                 .extra1         = &zero,
 863         },
 864         {
 865                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 866                 .procname       = "vfs_cache_pressure",
 867                 .data           = &sysctl_vfs_cache_pressure,
 868                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 869                 .mode           = 0644,
 870                 .proc_handler   = &proc_dointvec,
 871                 .strategy       = &sysctl_intvec,
 872                 .extra1         = &zero,
 873         },
 874 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 875         {
 876                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 877                 .procname       = "legacy_va_layout",
 878                 .data           = &sysctl_legacy_va_layout,
 879                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 880                 .mode           = 0644,
 881                 .proc_handler   = &proc_dointvec,
 882                 .strategy       = &sysctl_intvec,
 883                 .extra1         = &zero,
 884         },
 885 #endif
 886 #ifdef CONFIG_SWAP
 887         {
 888                 .ctl_name       = VM_SWAP_TOKEN_TIMEOUT,
 889                 .procname       = "swap_token_timeout",
 890                 .data           = &swap_token_default_timeout,
 891                 .maxlen         = sizeof(swap_token_default_timeout),
 892                 .mode           = 0644,
 893                 .proc_handler   = &proc_dointvec_jiffies,
 894                 .strategy       = &sysctl_jiffies,
 895         },
 896 #endif
 897 #ifdef CONFIG_NUMA
 898         {
 899                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 900                 .procname       = "zone_reclaim_mode",
 901                 .data           = &zone_reclaim_mode,
 902                 .maxlen         = sizeof(zone_reclaim_mode),
 903                 .mode           = 0644,
 904                 .proc_handler   = &proc_dointvec,
 905                 .strategy       = &sysctl_intvec,
 906                 .extra1         = &zero,
 907         },
 908         {
 909                 .ctl_name       = VM_ZONE_RECLAIM_INTERVAL,
 910                 .procname       = "zone_reclaim_interval",
 911                 .data           = &zone_reclaim_interval,
 912                 .maxlen         = sizeof(zone_reclaim_interval),
 913                 .mode           = 0644,
 914                 .proc_handler   = &proc_dointvec_jiffies,
 915                 .strategy       = &sysctl_jiffies,
 916         },
 917 #endif
 918         { .ctl_name = 0 }
 919 };
 920
 921 static ctl_table proc_table[] = {
 922         { .ctl_name = 0 }
 923 };
 924
 925 static ctl_table fs_table[] = {
 926         {
 927                 .ctl_name       = FS_NRINODE,
 928                 .procname       = "inode-nr",
 929                 .data           = &inodes_stat,
 930                 .maxlen         = 2*sizeof(int),
 931                 .mode           = 0444,
 932                 .proc_handler   = &proc_dointvec,
 933         },
 934         {
 935                 .ctl_name       = FS_STATINODE,
 936                 .procname       = "inode-state",
 937                 .data           = &inodes_stat,
 938                 .maxlen         = 7*sizeof(int),
 939                 .mode           = 0444,
 940                 .proc_handler   = &proc_dointvec,
 941         },
 942         {
 943                 .ctl_name       = FS_NRFILE,
 944                 .procname       = "file-nr",
 945                 .data           = &files_stat,
 946                 .maxlen         = 3*sizeof(int),
 947                 .mode           = 0444,
 948                 .proc_handler   = &proc_nr_files,
 949         },
 950         {
 951                 .ctl_name       = FS_MAXFILE,
 952                 .procname       = "file-max",
 953                 .data           = &files_stat.max_files,
 954                 .maxlen         = sizeof(int),
 955                 .mode           = 0644,
 956                 .proc_handler   = &proc_dointvec,
 957         },
 958         {
 959                 .ctl_name       = FS_DENTRY,
 960                 .procname       = "dentry-state",
 961                 .data           = &dentry_stat,
 962                 .maxlen         = 6*sizeof(int),
 963                 .mode           = 0444,
 964                 .proc_handler   = &proc_dointvec,
 965         },
 966         {
 967                 .ctl_name       = FS_OVERFLOWUID,
 968                 .procname       = "overflowuid",
 969                 .data           = &fs_overflowuid,
 970                 .maxlen         = sizeof(int),
 971                 .mode           = 0644,
 972                 .proc_handler   = &proc_dointvec_minmax,
 973                 .strategy       = &sysctl_intvec,
 974                 .extra1         = &minolduid,
 975                 .extra2         = &maxolduid,
 976         },
 977         {
 978                 .ctl_name       = FS_OVERFLOWGID,
 979                 .procname       = "overflowgid",
 980                 .data           = &fs_overflowgid,
 981                 .maxlen         = sizeof(int),
 982                 .mode           = 0644,
 983                 .proc_handler   = &proc_dointvec_minmax,
 984                 .strategy       = &sysctl_intvec,
 985                 .extra1         = &minolduid,
 986                 .extra2         = &maxolduid,
 987         },
 988         {
 989                 .ctl_name       = FS_LEASES,
 990                 .procname       = "leases-enable",
 991                 .data           = &leases_enable,
 992                 .maxlen         = sizeof(int),
 993                 .mode           = 0644,
 994                 .proc_handler   = &proc_dointvec,
 995         },
 996 #ifdef CONFIG_DNOTIFY
 997         {
 998                 .ctl_name       = FS_DIR_NOTIFY,
 999                 .procname       = "dir-notify-enable",
1000                 .data           = &dir_notify_enable,
1001                 .maxlen         = sizeof(int),
1002                 .mode           = 0644,
1003                 .proc_handler   = &proc_dointvec,
1004         },
1005 #endif
1006 #ifdef CONFIG_MMU
1007         {
1008                 .ctl_name       = FS_LEASE_TIME,
1009                 .procname       = "lease-break-time",
1010                 .data           = &lease_break_time,
1011                 .maxlen         = sizeof(int),
1012                 .mode           = 0644,
1013                 .proc_handler   = &proc_dointvec,
1014         },
1015         {
1016                 .ctl_name       = FS_AIO_NR,
1017                 .procname       = "aio-nr",
1018                 .data           = &aio_nr,
1019                 .maxlen         = sizeof(aio_nr),
1020                 .mode           = 0444,
1021                 .proc_handler   = &proc_doulongvec_minmax,
1022         },
1023         {
1024                 .ctl_name       = FS_AIO_MAX_NR,
1025                 .procname       = "aio-max-nr",
1026                 .data           = &aio_max_nr,
1027                 .maxlen         = sizeof(aio_max_nr),
1028                 .mode           = 0644,
1029                 .proc_handler   = &proc_doulongvec_minmax,
1030         },
1031 #ifdef CONFIG_INOTIFY
1032         {
1033                 .ctl_name       = FS_INOTIFY,
1034                 .procname       = "inotify",
1035                 .mode           = 0555,
1036                 .child          = inotify_table,
1037         },
1038 #endif
1039 #endif
1040         {
1041                 .ctl_name       = KERN_SETUID_DUMPABLE,
1042                 .procname       = "suid_dumpable",
1043                 .data           = &suid_dumpable,
1044                 .maxlen         = sizeof(int),
1045                 .mode           = 0644,
1046                 .proc_handler   = &proc_dointvec,
1047         },
1048         { .ctl_name = 0 }
1049 };
1050
1051 static ctl_table debug_table[] = {
1052         { .ctl_name = 0 }
1053 };
1054
1055 static ctl_table dev_table[] = {
1056         { .ctl_name = 0 }
1057 };
1058
1059 extern void init_irq_proc (void);
1060
1061 static DEFINE_SPINLOCK(sysctl_lock);
1062
1063 /* called under sysctl_lock */
1064 static int use_table(struct ctl_table_header *p)
1065 {
1066         if (unlikely(p->unregistering))
1067                 return 0;
1068         p->used++;
1069         return 1;
1070 }
1071
1072 /* called under sysctl_lock */
1073 static void unuse_table(struct ctl_table_header *p)
1074 {
1075         if (!--p->used)
1076                 if (unlikely(p->unregistering))
1077                         complete(p->unregistering);
1078 }
1079
1080 /* called under sysctl_lock, will reacquire if has to wait */
1081 static void start_unregistering(struct ctl_table_header *p)
1082 {
1083         /*
1084          * if p->used is 0, nobody will ever touch that entry again;
1085          * we'll eliminate all paths to it before dropping sysctl_lock
1086          */
1087         if (unlikely(p->used)) {
1088                 struct completion wait;
1089                 init_completion(&wait);
1090                 p->unregistering = &wait;
1091                 spin_unlock(&sysctl_lock);
1092                 wait_for_completion(&wait);
1093                 spin_lock(&sysctl_lock);
1094         }
1095         /*
1096          * do not remove from the list until nobody holds it; walking the
1097          * list in do_sysctl() relies on that.
1098          */
1099         list_del_init(&p->ctl_entry);
1100 }
1101
1102 void __init sysctl_init(void)
1103 {
1104 #ifdef CONFIG_PROC_FS
1105         register_proc_table(root_table, proc_sys_root, &root_table_header);
1106         init_irq_proc();
1107 #endif
1108 }
1109
1110 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1111                void __user *newval, size_t newlen)
1112 {
1113         struct list_head *tmp;
1114         int error = -ENOTDIR;
1115
1116         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1117                 return -ENOTDIR;
1118         if (oldval) {
1119                 int old_len;
1120                 if (!oldlenp || get_user(old_len, oldlenp))
1121                         return -EFAULT;
1122         }
1123         spin_lock(&sysctl_lock);
1124         tmp = &root_table_header.ctl_entry;
1125         do {
1126                 struct ctl_table_header *head =
1127                         list_entry(tmp, struct ctl_table_header, ctl_entry);
1128                 void *context = NULL;
1129
1130                 if (!use_table(head))
1131                         continue;
1132
1133                 spin_unlock(&sysctl_lock);
1134
1135                 error = parse_table(name, nlen, oldval, oldlenp,
1136                                         newval, newlen, head->ctl_table,
1137                                         &context);
1138                 kfree(context);
1139
1140                 spin_lock(&sysctl_lock);
1141                 unuse_table(head);
1142                 if (error != -ENOTDIR)
1143                         break;
1144         } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1145         spin_unlock(&sysctl_lock);
1146         return error;
1147 }
1148
1149 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1150 {
1151         struct __sysctl_args tmp;
1152         int error;
1153
1154         if (copy_from_user(&tmp, args, sizeof(tmp)))
1155                 return -EFAULT;
1156
1157         lock_kernel();
1158         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1159                           tmp.newval, tmp.newlen);
1160         unlock_kernel();
1161         return error;
1162 }
1163
1164 /*
1165  * ctl_perm does NOT grant the superuser all rights automatically, because
1166  * some sysctl variables are readonly even to root.
1167  */
1168
1169 static int test_perm(int mode, int op)
1170 {
1171         if (!current->euid)
1172                 mode >>= 6;
1173         else if (in_egroup_p(0))
1174                 mode >>= 3;
1175         if ((mode & op & 0007) == op)
1176                 return 0;
1177         return -EACCES;
1178 }
1179
1180 static inline int ctl_perm(ctl_table *table, int op)
1181 {
1182         int error;
1183         error = security_sysctl(table, op);
1184         if (error)
1185                 return error;
1186         return test_perm(table->mode, op);
1187 }
1188
1189 static int parse_table(int __user *name, int nlen,
1190                        void __user *oldval, size_t __user *oldlenp,
1191                        void __user *newval, size_t newlen,
1192                        ctl_table *table, void **context)
1193 {
1194         int n;
1195 repeat:
1196         if (!nlen)
1197                 return -ENOTDIR;
1198         if (get_user(n, name))
1199                 return -EFAULT;
1200         for ( ; table->ctl_name; table++) {
1201                 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1202                         int error;
1203                         if (table->child) {
1204                                 if (ctl_perm(table, 001))
1205                                         return -EPERM;
1206                                 if (table->strategy) {
1207                                         error = table->strategy(
1208                                                 table, name, nlen,
1209                                                 oldval, oldlenp,
1210                                                 newval, newlen, context);
1211                                         if (error)
1212                                                 return error;
1213                                 }
1214                                 name++;
1215                                 nlen--;
1216                                 table = table->child;
1217                                 goto repeat;
1218                         }
1219                         error = do_sysctl_strategy(table, name, nlen,
1220                                                    oldval, oldlenp,
1221                                                    newval, newlen, context);
1222                         return error;
1223                 }
1224         }
1225         return -ENOTDIR;
1226 }
1227
1228 /* Perform the actual read/write of a sysctl table entry. */
1229 int do_sysctl_strategy (ctl_table *table,
1230                         int __user *name, int nlen,
1231                         void __user *oldval, size_t __user *oldlenp,
1232                         void __user *newval, size_t newlen, void **context)
1233 {
1234         int op = 0, rc;
1235         size_t len;
1236
1237         if (oldval)
1238                 op |= 004;
1239         if (newval)
1240                 op |= 002;
1241         if (ctl_perm(table, op))
1242                 return -EPERM;
1243
1244         if (table->strategy) {
1245                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1246                                      newval, newlen, context);
1247                 if (rc < 0)
1248                         return rc;
1249                 if (rc > 0)
1250                         return 0;
1251         }
1252
1253         /* If there is no strategy routine, or if the strategy returns
1254          * zero, proceed with automatic r/w */
1255         if (table->data && table->maxlen) {
1256                 if (oldval && oldlenp) {
1257                         if (get_user(len, oldlenp))
1258                                 return -EFAULT;
1259                         if (len) {
1260                                 if (len > table->maxlen)
1261                                         len = table->maxlen;
1262                                 if(copy_to_user(oldval, table->data, len))
1263                                         return -EFAULT;
1264                                 if(put_user(len, oldlenp))
1265                                         return -EFAULT;
1266                         }
1267                 }
1268                 if (newval && newlen) {
1269                         len = newlen;
1270                         if (len > table->maxlen)
1271                                 len = table->maxlen;
1272                         if(copy_from_user(table->data, newval, len))
1273                                 return -EFAULT;
1274                 }
1275         }
1276         return 0;
1277 }
1278
1279 /**
1280  * register_sysctl_table - register a sysctl hierarchy
1281  * @table: the top-level table structure
1282  * @insert_at_head: whether the entry should be inserted in front or at the end
1283  *
1284  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1285  * array. An entry with a ctl_name of 0 terminates the table.
1286  *
1287  * The members of the &ctl_table structure are used as follows:
1288  *
1289  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1290  *            must be unique within that level of sysctl
1291  *
1292  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1293  *            enter a sysctl file
1294  *
1295  * data - a pointer to data for use by proc_handler
1296  *
1297  * maxlen - the maximum size in bytes of the data
1298  *
1299  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1300  *
1301  * child - a pointer to the child sysctl table if this entry is a directory, or
1302  *         %NULL.
1303  *
1304  * proc_handler - the text handler routine (described below)
1305  *
1306  * strategy - the strategy routine (described below)
1307  *
1308  * de - for internal use by the sysctl routines
1309  *
1310  * extra1, extra2 - extra pointers usable by the proc handler routines
1311  *
1312  * Leaf nodes in the sysctl tree will be represented by a single file
1313  * under /proc; non-leaf nodes will be represented by directories.
1314  *
1315  * sysctl(2) can automatically manage read and write requests through
1316  * the sysctl table.  The data and maxlen fields of the ctl_table
1317  * struct enable minimal validation of the values being written to be
1318  * performed, and the mode field allows minimal authentication.
1319  *
1320  * More sophisticated management can be enabled by the provision of a
1321  * strategy routine with the table entry.  This will be called before
1322  * any automatic read or write of the data is performed.
1323  *
1324  * The strategy routine may return
1325  *
1326  * < 0 - Error occurred (error is passed to user process)
1327  *
1328  * 0   - OK - proceed with automatic read or write.
1329  *
1330  * > 0 - OK - read or write has been done by the strategy routine, so
1331  *       return immediately.
1332  *
1333  * There must be a proc_handler routine for any terminal nodes
1334  * mirrored under /proc/sys (non-terminals are handled by a built-in
1335  * directory handler).  Several default handlers are available to
1336  * cover common cases -
1337  *
1338  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1339  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1340  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1341  *
1342  * It is the handler's job to read the input buffer from user memory
1343  * and process it. The handler should return 0 on success.
1344  *
1345  * This routine returns %NULL on a failure to register, and a pointer
1346  * to the table header on success.
1347  */
1348 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1349                                                int insert_at_head)
1350 {
1351         struct ctl_table_header *tmp;
1352         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1353         if (!tmp)
1354                 return NULL;
1355         tmp->ctl_table = table;
1356         INIT_LIST_HEAD(&tmp->ctl_entry);
1357         tmp->used = 0;
1358         tmp->unregistering = NULL;
1359         spin_lock(&sysctl_lock);
1360         if (insert_at_head)
1361                 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1362         else
1363                 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1364         spin_unlock(&sysctl_lock);
1365 #ifdef CONFIG_PROC_FS
1366         register_proc_table(table, proc_sys_root, tmp);
1367 #endif
1368         return tmp;
1369 }
1370
1371 /**
1372  * unregister_sysctl_table - unregister a sysctl table hierarchy
1373  * @header: the header returned from register_sysctl_table
1374  *
1375  * Unregisters the sysctl table and all children. proc entries may not
1376  * actually be removed until they are no longer used by anyone.
1377  */
1378 void unregister_sysctl_table(struct ctl_table_header * header)
1379 {
1380         might_sleep();
1381         spin_lock(&sysctl_lock);
1382         start_unregistering(header);
1383 #ifdef CONFIG_PROC_FS
1384         unregister_proc_table(header->ctl_table, proc_sys_root);
1385 #endif
1386         spin_unlock(&sysctl_lock);
1387         kfree(header);
1388 }
1389
1390 /*
1391  * /proc/sys support
1392  */
1393
1394 #ifdef CONFIG_PROC_FS
1395
1396 /* Scan the sysctl entries in table and add them all into /proc */
1397 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1398 {
1399         struct proc_dir_entry *de;
1400         int len;
1401         mode_t mode;
1402
1403         for (; table->ctl_name; table++) {
1404                 /* Can't do anything without a proc name. */
1405                 if (!table->procname)
1406                         continue;
1407                 /* Maybe we can't do anything with it... */
1408                 if (!table->proc_handler && !table->child) {
1409                         printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1410                                 table->procname);
1411                         continue;
1412                 }
1413
1414                 len = strlen(table->procname);
1415                 mode = table->mode;
1416
1417                 de = NULL;
1418                 if (table->proc_handler)
1419                         mode |= S_IFREG;
1420                 else {
1421                         mode |= S_IFDIR;
1422                         for (de = root->subdir; de; de = de->next) {
1423                                 if (proc_match(len, table->procname, de))
1424                                         break;
1425                         }
1426                         /* If the subdir exists already, de is non-NULL */
1427                 }
1428
1429                 if (!de) {
1430                         de = create_proc_entry(table->procname, mode, root);
1431                         if (!de)
1432                                 continue;
1433                         de->set = set;
1434                         de->data = (void *) table;
1435                         if (table->proc_handler)
1436                                 de->proc_fops = &proc_sys_file_operations;
1437                 }
1438                 table->de = de;
1439                 if (de->mode & S_IFDIR)
1440                         register_proc_table(table->child, de, set);
1441         }
1442 }
1443
1444 /*
1445  * Unregister a /proc sysctl table and any subdirectories.
1446  */
1447 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1448 {
1449         struct proc_dir_entry *de;
1450         for (; table->ctl_name; table++) {
1451                 if (!(de = table->de))
1452                         continue;
1453                 if (de->mode & S_IFDIR) {
1454                         if (!table->child) {
1455                                 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1456                                 continue;
1457                         }
1458                         unregister_proc_table(table->child, de);
1459
1460                         /* Don't unregister directories which still have entries.. */
1461                         if (de->subdir)
1462                                 continue;
1463                 }
1464
1465                 /*
1466                  * In any case, mark the entry as goner; we'll keep it
1467                  * around if it's busy, but we'll know to do nothing with
1468                  * its fields.  We are under sysctl_lock here.
1469                  */
1470                 de->data = NULL;
1471
1472                 /* Don't unregister proc entries that are still being used.. */
1473                 if (atomic_read(&de->count))
1474                         continue;
1475
1476                 table->de = NULL;
1477                 remove_proc_entry(table->procname, root);
1478         }
1479 }
1480
1481 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1482                           size_t count, loff_t *ppos)
1483 {
1484         int op;
1485         struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
1486         struct ctl_table *table;
1487         size_t res;
1488         ssize_t error = -ENOTDIR;
1489
1490         spin_lock(&sysctl_lock);
1491         if (de && de->data && use_table(de->set)) {
1492                 /*
1493                  * at that point we know that sysctl was not unregistered
1494                  * and won't be until we finish
1495                  */
1496                 spin_unlock(&sysctl_lock);
1497                 table = (struct ctl_table *) de->data;
1498                 if (!table || !table->proc_handler)
1499                         goto out;
1500                 error = -EPERM;
1501                 op = (write ? 002 : 004);
1502                 if (ctl_perm(table, op))
1503                         goto out;
1504
1505                 /* careful: calling conventions are nasty here */
1506                 res = count;
1507                 error = (*table->proc_handler)(table, write, file,
1508                                                 buf, &res, ppos);
1509                 if (!error)
1510                         error = res;
1511         out:
1512                 spin_lock(&sysctl_lock);
1513                 unuse_table(de->set);
1514         }
1515         spin_unlock(&sysctl_lock);
1516         return error;
1517 }
1518
1519 static int proc_opensys(struct inode *inode, struct file *file)
1520 {
1521         if (file->f_mode & FMODE_WRITE) {
1522                 /*
1523                  * sysctl entries that are not writable,
1524                  * are _NOT_ writable, capabilities or not.
1525                  */
1526                 if (!(inode->i_mode & S_IWUSR))
1527                         return -EPERM;
1528         }
1529
1530         return 0;
1531 }
1532
1533 static ssize_t proc_readsys(struct file * file, char __user * buf,
1534                             size_t count, loff_t *ppos)
1535 {
1536         return do_rw_proc(0, file, buf, count, ppos);
1537 }
1538
1539 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1540                              size_t count, loff_t *ppos)
1541 {
1542         return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1543 }
1544
1545 /**
1546  * proc_dostring - read a string sysctl
1547  * @table: the sysctl table
1548  * @write: %TRUE if this is a write to the sysctl file
1549  * @filp: the file structure
1550  * @buffer: the user buffer
1551  * @lenp: the size of the user buffer
1552  * @ppos: file position
1553  *
1554  * Reads/writes a string from/to the user buffer. If the kernel
1555  * buffer provided is not large enough to hold the string, the
1556  * string is truncated. The copied string is %NULL-terminated.
1557  * If the string is being read by the user process, it is copied
1558  * and a newline '\n' is added. It is truncated if the buffer is
1559  * not large enough.
1560  *
1561  * Returns 0 on success.
1562  */
1563 int proc_dostring(ctl_table *table, int write, struct file *filp,
1564                   void __user *buffer, size_t *lenp, loff_t *ppos)
1565 {
1566         size_t len;
1567         char __user *p;
1568         char c;
1569
1570         if (!table->data || !table->maxlen || !*lenp ||
1571             (*ppos && !write)) {
1572                 *lenp = 0;
1573                 return 0;
1574         }
1575
1576         if (write) {
1577                 len = 0;
1578                 p = buffer;
1579                 while (len < *lenp) {
1580                         if (get_user(c, p++))
1581                                 return -EFAULT;
1582                         if (c == 0 || c == '\n')
1583                                 break;
1584                         len++;
1585                 }
1586                 if (len >= table->maxlen)
1587                         len = table->maxlen-1;
1588                 if(copy_from_user(table->data, buffer, len))
1589                         return -EFAULT;
1590                 ((char *) table->data)[len] = 0;
1591                 *ppos += *lenp;
1592         } else {
1593                 len = strlen(table->data);
1594                 if (len > table->maxlen)
1595                         len = table->maxlen;
1596                 if (len > *lenp)
1597                         len = *lenp;
1598                 if (len)
1599                         if(copy_to_user(buffer, table->data, len))
1600                                 return -EFAULT;
1601                 if (len < *lenp) {
1602                         if(put_user('\n', ((char __user *) buffer) + len))
1603                                 return -EFAULT;
1604                         len++;
1605                 }
1606                 *lenp = len;
1607                 *ppos += len;
1608         }
1609         return 0;
1610 }
1611
1612 /*
1613  *      Special case of dostring for the UTS structure. This has locks
1614  *      to observe. Should this be in kernel/sys.c ????
1615  */
1616
1617 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1618                   void __user *buffer, size_t *lenp, loff_t *ppos)
1619 {
1620         int r;
1621
1622         if (!write) {
1623                 down_read(&uts_sem);
1624                 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1625                 up_read(&uts_sem);
1626         } else {
1627                 down_write(&uts_sem);
1628                 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1629                 up_write(&uts_sem);
1630         }
1631         return r;
1632 }
1633
1634 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1635                                  int *valp,
1636                                  int write, void *data)
1637 {
1638         if (write) {
1639                 *valp = *negp ? -*lvalp : *lvalp;
1640         } else {
1641                 int val = *valp;
1642                 if (val < 0) {
1643                         *negp = -1;
1644                         *lvalp = (unsigned long)-val;
1645                 } else {
1646                         *negp = 0;
1647                         *lvalp = (unsigned long)val;
1648                 }
1649         }
1650         return 0;
1651 }
1652
1653 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1654                   void __user *buffer, size_t *lenp, loff_t *ppos,
1655                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1656                               int write, void *data),
1657                   void *data)
1658 {
1659 #define TMPBUFLEN 21
1660         int *i, vleft, first=1, neg, val;
1661         unsigned long lval;
1662         size_t left, len;
1663
1664         char buf[TMPBUFLEN], *p;
1665         char __user *s = buffer;
1666
1667         if (!table->data || !table->maxlen || !*lenp ||
1668             (*ppos && !write)) {
1669                 *lenp = 0;
1670                 return 0;
1671         }
1672
1673         i = (int *) table->data;
1674         vleft = table->maxlen / sizeof(*i);
1675         left = *lenp;
1676
1677         if (!conv)
1678                 conv = do_proc_dointvec_conv;
1679
1680         for (; left && vleft--; i++, first=0) {
1681                 if (write) {
1682                         while (left) {
1683                                 char c;
1684                                 if (get_user(c, s))
1685                                         return -EFAULT;
1686                                 if (!isspace(c))
1687                                         break;
1688                                 left--;
1689                                 s++;
1690                         }
1691                         if (!left)
1692                                 break;
1693                         neg = 0;
1694                         len = left;
1695                         if (len > sizeof(buf) - 1)
1696                                 len = sizeof(buf) - 1;
1697                         if (copy_from_user(buf, s, len))
1698                                 return -EFAULT;
1699                         buf[len] = 0;
1700                         p = buf;
1701                         if (*p == '-' && left > 1) {
1702                                 neg = 1;
1703                                 left--, p++;
1704                         }
1705                         if (*p < '0' || *p > '9')
1706                                 break;
1707
1708                         lval = simple_strtoul(p, &p, 0);
1709
1710                         len = p-buf;
1711                         if ((len < left) && *p && !isspace(*p))
1712                                 break;
1713                         if (neg)
1714                                 val = -val;
1715                         s += len;
1716                         left -= len;
1717
1718                         if (conv(&neg, &lval, i, 1, data))
1719                                 break;
1720                 } else {
1721                         p = buf;
1722                         if (!first)
1723                                 *p++ = '\t';
1724
1725                         if (conv(&neg, &lval, i, 0, data))
1726                                 break;
1727
1728                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1729                         len = strlen(buf);
1730                         if (len > left)
1731                                 len = left;
1732                         if(copy_to_user(s, buf, len))
1733                                 return -EFAULT;
1734                         left -= len;
1735                         s += len;
1736                 }
1737         }
1738
1739         if (!write && !first && left) {
1740                 if(put_user('\n', s))
1741                         return -EFAULT;
1742                 left--, s++;
1743         }
1744         if (write) {
1745                 while (left) {
1746                         char c;
1747                         if (get_user(c, s++))
1748                                 return -EFAULT;
1749                         if (!isspace(c))
1750                                 break;
1751                         left--;
1752                 }
1753         }
1754         if (write && first)
1755                 return -EINVAL;
1756         *lenp -= left;
1757         *ppos += *lenp;
1758         return 0;
1759 #undef TMPBUFLEN
1760 }
1761
1762 /**
1763  * proc_dointvec - read a vector of integers
1764  * @table: the sysctl table
1765  * @write: %TRUE if this is a write to the sysctl file
1766  * @filp: the file structure
1767  * @buffer: the user buffer
1768  * @lenp: the size of the user buffer
1769  * @ppos: file position
1770  *
1771  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1772  * values from/to the user buffer, treated as an ASCII string.
1773  *
1774  * Returns 0 on success.
1775  */
1776 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1777                      void __user *buffer, size_t *lenp, loff_t *ppos)
1778 {
1779     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1780                             NULL,NULL);
1781 }
1782
1783 #define OP_SET  0
1784 #define OP_AND  1
1785 #define OP_OR   2
1786 #define OP_MAX  3
1787 #define OP_MIN  4
1788
1789 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1790                                       int *valp,
1791                                       int write, void *data)
1792 {
1793         int op = *(int *)data;
1794         if (write) {
1795                 int val = *negp ? -*lvalp : *lvalp;
1796                 switch(op) {
1797                 case OP_SET:    *valp = val; break;
1798                 case OP_AND:    *valp &= val; break;
1799                 case OP_OR:     *valp |= val; break;
1800                 case OP_MAX:    if(*valp < val)
1801                                         *valp = val;
1802                                 break;
1803                 case OP_MIN:    if(*valp > val)
1804                                 *valp = val;
1805                                 break;
1806                 }
1807         } else {
1808                 int val = *valp;
1809                 if (val < 0) {
1810                         *negp = -1;
1811                         *lvalp = (unsigned long)-val;
1812                 } else {
1813                         *negp = 0;
1814                         *lvalp = (unsigned long)val;
1815                 }
1816         }
1817         return 0;
1818 }
1819
1820 /*
1821  *      init may raise the set.
1822  */
1823
1824 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1825                         void __user *buffer, size_t *lenp, loff_t *ppos)
1826 {
1827         int op;
1828
1829         if (!capable(CAP_SYS_MODULE)) {
1830                 return -EPERM;
1831         }
1832
1833         op = (current->pid == 1) ? OP_SET : OP_AND;
1834         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1835                                 do_proc_dointvec_bset_conv,&op);
1836 }
1837
1838 struct do_proc_dointvec_minmax_conv_param {
1839         int *min;
1840         int *max;
1841 };
1842
1843 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1844                                         int *valp,
1845                                         int write, void *data)
1846 {
1847         struct do_proc_dointvec_minmax_conv_param *param = data;
1848         if (write) {
1849                 int val = *negp ? -*lvalp : *lvalp;
1850                 if ((param->min && *param->min > val) ||
1851                     (param->max && *param->max < val))
1852                         return -EINVAL;
1853                 *valp = val;
1854         } else {
1855                 int val = *valp;
1856                 if (val < 0) {
1857                         *negp = -1;
1858                         *lvalp = (unsigned long)-val;
1859                 } else {
1860                         *negp = 0;
1861                         *lvalp = (unsigned long)val;
1862                 }
1863         }
1864         return 0;
1865 }
1866
1867 /**
1868  * proc_dointvec_minmax - read a vector of integers with min/max values
1869  * @table: the sysctl table
1870  * @write: %TRUE if this is a write to the sysctl file
1871  * @filp: the file structure
1872  * @buffer: the user buffer
1873  * @lenp: the size of the user buffer
1874  * @ppos: file position
1875  *
1876  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1877  * values from/to the user buffer, treated as an ASCII string.
1878  *
1879  * This routine will ensure the values are within the range specified by
1880  * table->extra1 (min) and table->extra2 (max).
1881  *
1882  * Returns 0 on success.
1883  */
1884 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1885                   void __user *buffer, size_t *lenp, loff_t *ppos)
1886 {
1887         struct do_proc_dointvec_minmax_conv_param param = {
1888                 .min = (int *) table->extra1,
1889                 .max = (int *) table->extra2,
1890         };
1891         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1892                                 do_proc_dointvec_minmax_conv, &param);
1893 }
1894
1895 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1896                                      struct file *filp,
1897                                      void __user *buffer,
1898                                      size_t *lenp, loff_t *ppos,
1899                                      unsigned long convmul,
1900                                      unsigned long convdiv)
1901 {
1902 #define TMPBUFLEN 21
1903         unsigned long *i, *min, *max, val;
1904         int vleft, first=1, neg;
1905         size_t len, left;
1906         char buf[TMPBUFLEN], *p;
1907         char __user *s = buffer;
1908
1909         if (!table->data || !table->maxlen || !*lenp ||
1910             (*ppos && !write)) {
1911                 *lenp = 0;
1912                 return 0;
1913         }
1914
1915         i = (unsigned long *) table->data;
1916         min = (unsigned long *) table->extra1;
1917         max = (unsigned long *) table->extra2;
1918         vleft = table->maxlen / sizeof(unsigned long);
1919         left = *lenp;
1920
1921         for (; left && vleft--; i++, min++, max++, first=0) {
1922                 if (write) {
1923                         while (left) {
1924                                 char c;
1925                                 if (get_user(c, s))
1926                                         return -EFAULT;
1927                                 if (!isspace(c))
1928                                         break;
1929                                 left--;
1930                                 s++;
1931                         }
1932                         if (!left)
1933                                 break;
1934                         neg = 0;
1935                         len = left;
1936                         if (len > TMPBUFLEN-1)
1937                                 len = TMPBUFLEN-1;
1938                         if (copy_from_user(buf, s, len))
1939                                 return -EFAULT;
1940                         buf[len] = 0;
1941                         p = buf;
1942                         if (*p == '-' && left > 1) {
1943                                 neg = 1;
1944                                 left--, p++;
1945                         }
1946                         if (*p < '0' || *p > '9')
1947                                 break;
1948                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1949                         len = p-buf;
1950                         if ((len < left) && *p && !isspace(*p))
1951                                 break;
1952                         if (neg)
1953                                 val = -val;
1954                         s += len;
1955                         left -= len;
1956
1957                         if(neg)
1958                                 continue;
1959                         if ((min && val < *min) || (max && val > *max))
1960                                 continue;
1961                         *i = val;
1962                 } else {
1963                         p = buf;
1964                         if (!first)
1965                                 *p++ = '\t';
1966                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1967                         len = strlen(buf);
1968                         if (len > left)
1969                                 len = left;
1970                         if(copy_to_user(s, buf, len))
1971                                 return -EFAULT;
1972                         left -= len;
1973                         s += len;
1974                 }
1975         }
1976
1977         if (!write && !first && left) {
1978                 if(put_user('\n', s))
1979                         return -EFAULT;
1980                 left--, s++;
1981         }
1982         if (write) {
1983                 while (left) {
1984                         char c;
1985                         if (get_user(c, s++))
1986                                 return -EFAULT;
1987                         if (!isspace(c))
1988                                 break;
1989                         left--;
1990                 }
1991         }
1992         if (write && first)
1993                 return -EINVAL;
1994         *lenp -= left;
1995         *ppos += *lenp;
1996         return 0;
1997 #undef TMPBUFLEN
1998 }
1999
2000 /**
2001  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2002  * @table: the sysctl table
2003  * @write: %TRUE if this is a write to the sysctl file
2004  * @filp: the file structure
2005  * @buffer: the user buffer
2006  * @lenp: the size of the user buffer
2007  * @ppos: file position
2008  *
2009  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2010  * values from/to the user buffer, treated as an ASCII string.
2011  *
2012  * This routine will ensure the values are within the range specified by
2013  * table->extra1 (min) and table->extra2 (max).
2014  *
2015  * Returns 0 on success.
2016  */
2017 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2018                            void __user *buffer, size_t *lenp, loff_t *ppos)
2019 {
2020     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2021 }
2022
2023 /**
2024  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2025  * @table: the sysctl table
2026  * @write: %TRUE if this is a write to the sysctl file
2027  * @filp: the file structure
2028  * @buffer: the user buffer
2029  * @lenp: the size of the user buffer
2030  * @ppos: file position
2031  *
2032  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2033  * values from/to the user buffer, treated as an ASCII string. The values
2034  * are treated as milliseconds, and converted to jiffies when they are stored.
2035  *
2036  * This routine will ensure the values are within the range specified by
2037  * table->extra1 (min) and table->extra2 (max).
2038  *
2039  * Returns 0 on success.
2040  */
2041 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2042                                       struct file *filp,
2043                                       void __user *buffer,
2044                                       size_t *lenp, loff_t *ppos)
2045 {
2046     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2047                                      lenp, ppos, HZ, 1000l);
2048 }
2049
2050
2051 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2052                                          int *valp,
2053                                          int write, void *data)
2054 {
2055         if (write) {
2056                 if (*lvalp > LONG_MAX / HZ)
2057                         return 1;
2058                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2059         } else {
2060                 int val = *valp;
2061                 unsigned long lval;
2062                 if (val < 0) {
2063                         *negp = -1;
2064                         lval = (unsigned long)-val;
2065                 } else {
2066                         *negp = 0;
2067                         lval = (unsigned long)val;
2068                 }
2069                 *lvalp = lval / HZ;
2070         }
2071         return 0;
2072 }
2073
2074 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2075                                                 int *valp,
2076                                                 int write, void *data)
2077 {
2078         if (write) {
2079                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2080                         return 1;
2081                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2082         } else {
2083                 int val = *valp;
2084                 unsigned long lval;
2085                 if (val < 0) {
2086                         *negp = -1;
2087                         lval = (unsigned long)-val;
2088                 } else {
2089                         *negp = 0;
2090                         lval = (unsigned long)val;
2091                 }
2092                 *lvalp = jiffies_to_clock_t(lval);
2093         }
2094         return 0;
2095 }
2096
2097 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2098                                             int *valp,
2099                                             int write, void *data)
2100 {
2101         if (write) {
2102                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2103         } else {
2104                 int val = *valp;
2105                 unsigned long lval;
2106                 if (val < 0) {
2107                         *negp = -1;
2108                         lval = (unsigned long)-val;
2109                 } else {
2110                         *negp = 0;
2111                         lval = (unsigned long)val;
2112                 }
2113                 *lvalp = jiffies_to_msecs(lval);
2114         }
2115         return 0;
2116 }
2117
2118 /**
2119  * proc_dointvec_jiffies - read a vector of integers as seconds
2120  * @table: the sysctl table
2121  * @write: %TRUE if this is a write to the sysctl file
2122  * @filp: the file structure
2123  * @buffer: the user buffer
2124  * @lenp: the size of the user buffer
2125  * @ppos: file position
2126  *
2127  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2128  * values from/to the user buffer, treated as an ASCII string.
2129  * The values read are assumed to be in seconds, and are converted into
2130  * jiffies.
2131  *
2132  * Returns 0 on success.
2133  */
2134 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2135                           void __user *buffer, size_t *lenp, loff_t *ppos)
2136 {
2137     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2138                             do_proc_dointvec_jiffies_conv,NULL);
2139 }
2140
2141 /**
2142  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2143  * @table: the sysctl table
2144  * @write: %TRUE if this is a write to the sysctl file
2145  * @filp: the file structure
2146  * @buffer: the user buffer
2147  * @lenp: the size of the user buffer
2148  * @ppos: pointer to the file position
2149  *
2150  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2151  * values from/to the user buffer, treated as an ASCII string.
2152  * The values read are assumed to be in 1/USER_HZ seconds, and
2153  * are converted into jiffies.
2154  *
2155  * Returns 0 on success.
2156  */
2157 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2158                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2159 {
2160     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2161                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2162 }
2163
2164 /**
2165  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2166  * @table: the sysctl table
2167  * @write: %TRUE if this is a write to the sysctl file
2168  * @filp: the file structure
2169  * @buffer: the user buffer
2170  * @lenp: the size of the user buffer
2171  * @ppos: file position
2172  * @ppos: the current position in the file
2173  *
2174  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2175  * values from/to the user buffer, treated as an ASCII string.
2176  * The values read are assumed to be in 1/1000 seconds, and
2177  * are converted into jiffies.
2178  *
2179  * Returns 0 on success.
2180  */
2181 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2182                              void __user *buffer, size_t *lenp, loff_t *ppos)
2183 {
2184         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2185                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2186 }
2187
2188 #else /* CONFIG_PROC_FS */
2189
2190 int proc_dostring(ctl_table *table, int write, struct file *filp,
2191                   void __user *buffer, size_t *lenp, loff_t *ppos)
2192 {
2193         return -ENOSYS;
2194 }
2195
2196 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2197                             void __user *buffer, size_t *lenp, loff_t *ppos)
2198 {
2199         return -ENOSYS;
2200 }
2201
2202 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2203                   void __user *buffer, size_t *lenp, loff_t *ppos)
2204 {
2205         return -ENOSYS;
2206 }
2207
2208 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2209                         void __user *buffer, size_t *lenp, loff_t *ppos)
2210 {
2211         return -ENOSYS;
2212 }
2213
2214 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2215                     void __user *buffer, size_t *lenp, loff_t *ppos)
2216 {
2217         return -ENOSYS;
2218 }
2219
2220 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2221                     void __user *buffer, size_t *lenp, loff_t *ppos)
2222 {
2223         return -ENOSYS;
2224 }
2225
2226 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2227                     void __user *buffer, size_t *lenp, loff_t *ppos)
2228 {
2229         return -ENOSYS;
2230 }
2231
2232 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2233                              void __user *buffer, size_t *lenp, loff_t *ppos)
2234 {
2235         return -ENOSYS;
2236 }
2237
2238 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2239                     void __user *buffer, size_t *lenp, loff_t *ppos)
2240 {
2241         return -ENOSYS;
2242 }
2243
2244 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2245                                       struct file *filp,
2246                                       void __user *buffer,
2247                                       size_t *lenp, loff_t *ppos)
2248 {
2249     return -ENOSYS;
2250 }
2251
2252
2253 #endif /* CONFIG_PROC_FS */
2254
2255
2256 /*
2257  * General sysctl support routines
2258  */
2259
2260 /* The generic string strategy routine: */
2261 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2262                   void __user *oldval, size_t __user *oldlenp,
2263                   void __user *newval, size_t newlen, void **context)
2264 {
2265         if (!table->data || !table->maxlen)
2266                 return -ENOTDIR;
2267
2268         if (oldval && oldlenp) {
2269                 size_t bufsize;
2270                 if (get_user(bufsize, oldlenp))
2271                         return -EFAULT;
2272                 if (bufsize) {
2273                         size_t len = strlen(table->data), copied;
2274
2275                         /* This shouldn't trigger for a well-formed sysctl */
2276                         if (len > table->maxlen)
2277                                 len = table->maxlen;
2278
2279                         /* Copy up to a max of bufsize-1 bytes of the string */
2280                         copied = (len >= bufsize) ? bufsize - 1 : len;
2281
2282                         if (copy_to_user(oldval, table->data, copied) ||
2283                             put_user(0, (char __user *)(oldval + copied)))
2284                                 return -EFAULT;
2285                         if (put_user(len, oldlenp))
2286                                 return -EFAULT;
2287                 }
2288         }
2289         if (newval && newlen) {
2290                 size_t len = newlen;
2291                 if (len > table->maxlen)
2292                         len = table->maxlen;
2293                 if(copy_from_user(table->data, newval, len))
2294                         return -EFAULT;
2295                 if (len == table->maxlen)
2296                         len--;
2297                 ((char *) table->data)[len] = 0;
2298         }
2299         return 1;
2300 }
2301
2302 /*
2303  * This function makes sure that all of the integers in the vector
2304  * are between the minimum and maximum values given in the arrays
2305  * table->extra1 and table->extra2, respectively.
2306  */
2307 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2308                 void __user *oldval, size_t __user *oldlenp,
2309                 void __user *newval, size_t newlen, void **context)
2310 {
2311
2312         if (newval && newlen) {
2313                 int __user *vec = (int __user *) newval;
2314                 int *min = (int *) table->extra1;
2315                 int *max = (int *) table->extra2;
2316                 size_t length;
2317                 int i;
2318
2319                 if (newlen % sizeof(int) != 0)
2320                         return -EINVAL;
2321
2322                 if (!table->extra1 && !table->extra2)
2323                         return 0;
2324
2325                 if (newlen > table->maxlen)
2326                         newlen = table->maxlen;
2327                 length = newlen / sizeof(int);
2328
2329                 for (i = 0; i < length; i++) {
2330                         int value;
2331                         if (get_user(value, vec + i))
2332                                 return -EFAULT;
2333                         if (min && value < min[i])
2334                                 return -EINVAL;
2335                         if (max && value > max[i])
2336                                 return -EINVAL;
2337                 }
2338         }
2339         return 0;
2340 }
2341
2342 /* Strategy function to convert jiffies to seconds */
2343 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2344                 void __user *oldval, size_t __user *oldlenp,
2345                 void __user *newval, size_t newlen, void **context)
2346 {
2347         if (oldval) {
2348                 size_t olen;
2349                 if (oldlenp) {
2350                         if (get_user(olen, oldlenp))
2351                                 return -EFAULT;
2352                         if (olen!=sizeof(int))
2353                                 return -EINVAL;
2354                 }
2355                 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2356                     (oldlenp && put_user(sizeof(int),oldlenp)))
2357                         return -EFAULT;
2358         }
2359         if (newval && newlen) {
2360                 int new;
2361                 if (newlen != sizeof(int))
2362                         return -EINVAL;
2363                 if (get_user(new, (int __user *)newval))
2364                         return -EFAULT;
2365                 *(int *)(table->data) = new*HZ;
2366         }
2367         return 1;
2368 }
2369
2370 /* Strategy function to convert jiffies to seconds */
2371 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2372                 void __user *oldval, size_t __user *oldlenp,
2373                 void __user *newval, size_t newlen, void **context)
2374 {
2375         if (oldval) {
2376                 size_t olen;
2377                 if (oldlenp) {
2378                         if (get_user(olen, oldlenp))
2379                                 return -EFAULT;
2380                         if (olen!=sizeof(int))
2381                                 return -EINVAL;
2382                 }
2383                 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2384                     (oldlenp && put_user(sizeof(int),oldlenp)))
2385                         return -EFAULT;
2386         }
2387         if (newval && newlen) {
2388                 int new;
2389                 if (newlen != sizeof(int))
2390                         return -EINVAL;
2391                 if (get_user(new, (int __user *)newval))
2392                         return -EFAULT;
2393                 *(int *)(table->data) = msecs_to_jiffies(new);
2394         }
2395         return 1;
2396 }
2397
2398 #else /* CONFIG_SYSCTL */
2399
2400
2401 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2402 {
2403         return -ENOSYS;
2404 }
2405
2406 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2407                   void __user *oldval, size_t __user *oldlenp,
2408                   void __user *newval, size_t newlen, void **context)
2409 {
2410         return -ENOSYS;
2411 }
2412
2413 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2414                 void __user *oldval, size_t __user *oldlenp,
2415                 void __user *newval, size_t newlen, void **context)
2416 {
2417         return -ENOSYS;
2418 }
2419
2420 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2421                 void __user *oldval, size_t __user *oldlenp,
2422                 void __user *newval, size_t newlen, void **context)
2423 {
2424         return -ENOSYS;
2425 }
2426
2427 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2428                 void __user *oldval, size_t __user *oldlenp,
2429                 void __user *newval, size_t newlen, void **context)
2430 {
2431         return -ENOSYS;
2432 }
2433
2434 int proc_dostring(ctl_table *table, int write, struct file *filp,
2435                   void __user *buffer, size_t *lenp, loff_t *ppos)
2436 {
2437         return -ENOSYS;
2438 }
2439
2440 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2441                   void __user *buffer, size_t *lenp, loff_t *ppos)
2442 {
2443         return -ENOSYS;
2444 }
2445
2446 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2447                         void __user *buffer, size_t *lenp, loff_t *ppos)
2448 {
2449         return -ENOSYS;
2450 }
2451
2452 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2453                     void __user *buffer, size_t *lenp, loff_t *ppos)
2454 {
2455         return -ENOSYS;
2456 }
2457
2458 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2459                           void __user *buffer, size_t *lenp, loff_t *ppos)
2460 {
2461         return -ENOSYS;
2462 }
2463
2464 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2465                           void __user *buffer, size_t *lenp, loff_t *ppos)
2466 {
2467         return -ENOSYS;
2468 }
2469
2470 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2471                              void __user *buffer, size_t *lenp, loff_t *ppos)
2472 {
2473         return -ENOSYS;
2474 }
2475
2476 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2477                     void __user *buffer, size_t *lenp, loff_t *ppos)
2478 {
2479         return -ENOSYS;
2480 }
2481
2482 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2483                                       struct file *filp,
2484                                       void __user *buffer,
2485                                       size_t *lenp, loff_t *ppos)
2486 {
2487     return -ENOSYS;
2488 }
2489
2490 struct ctl_table_header * register_sysctl_table(ctl_table * table,
2491                                                 int insert_at_head)
2492 {
2493         return NULL;
2494 }
2495
2496 void unregister_sysctl_table(struct ctl_table_header * table)
2497 {
2498 }
2499
2500 #endif /* CONFIG_SYSCTL */
2501
2502 /*
2503  * No sense putting this after each symbol definition, twice,
2504  * exception granted :-)
2505  */
2506 EXPORT_SYMBOL(proc_dointvec);
2507 EXPORT_SYMBOL(proc_dointvec_jiffies);
2508 EXPORT_SYMBOL(proc_dointvec_minmax);
2509 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2510 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2511 EXPORT_SYMBOL(proc_dostring);
2512 EXPORT_SYMBOL(proc_doulongvec_minmax);
2513 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2514 EXPORT_SYMBOL(register_sysctl_table);
2515 EXPORT_SYMBOL(sysctl_intvec);
2516 EXPORT_SYMBOL(sysctl_jiffies);
2517 EXPORT_SYMBOL(sysctl_ms_jiffies);
2518 EXPORT_SYMBOL(sysctl_string);
2519 EXPORT_SYMBOL(unregister_sysctl_table);