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