kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/config.h>
  22 #include <linux/module.h>
  23 #include <linux/mm.h>
  24 #include <linux/swap.h>
  25 #include <linux/slab.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/capability.h>
  29 #include <linux/ctype.h>
  30 #include <linux/utsname.h>
  31 #include <linux/capability.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/security.h>
  42 #include <linux/initrd.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49
  50 #include <asm/uaccess.h>
  51 #include <asm/processor.h>
  52
  53 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
  54                      void __user *buffer, size_t *lenp, loff_t *ppos);
  55
  56 #if defined(CONFIG_SYSCTL)
  57
  58 /* External variables not in a header file. */
  59 extern int C_A_D;
  60 extern int sysctl_overcommit_memory;
  61 extern int sysctl_overcommit_ratio;
  62 extern int sysctl_panic_on_oom;
  63 extern int max_threads;
  64 extern int sysrq_enabled;
  65 extern int core_uses_pid;
  66 extern int suid_dumpable;
  67 extern char core_pattern[];
  68 extern int cad_pid;
  69 extern int pid_max;
  70 extern int min_free_kbytes;
  71 extern int printk_ratelimit_jiffies;
  72 extern int printk_ratelimit_burst;
  73 extern int pid_max_min, pid_max_max;
  74 extern int sysctl_drop_caches;
  75 extern int percpu_pagelist_fraction;
  76 extern int compat_log;
  77
  78 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
  79 int unknown_nmi_panic;
  80 extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *,
  81                                   void __user *, size_t *, loff_t *);
  82 #endif
  83
  84 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  85 static int maxolduid = 65535;
  86 static int minolduid;
  87 static int min_percpu_pagelist_fract = 8;
  88
  89 static int ngroups_max = NGROUPS_MAX;
  90
  91 #ifdef CONFIG_KMOD
  92 extern char modprobe_path[];
  93 #endif
  94 #ifdef CONFIG_CHR_DEV_SG
  95 extern int sg_big_buff;
  96 #endif
  97 #ifdef CONFIG_SYSVIPC
  98 extern size_t shm_ctlmax;
  99 extern size_t shm_ctlall;
 100 extern int shm_ctlmni;
 101 extern int msg_ctlmax;
 102 extern int msg_ctlmnb;
 103 extern int msg_ctlmni;
 104 extern int sem_ctls[];
 105 #endif
 106
 107 #ifdef __sparc__
 108 extern char reboot_command [];
 109 extern int stop_a_enabled;
 110 extern int scons_pwroff;
 111 #endif
 112
 113 #ifdef __hppa__
 114 extern int pwrsw_enabled;
 115 extern int unaligned_enabled;
 116 #endif
 117
 118 #ifdef CONFIG_S390
 119 #ifdef CONFIG_MATHEMU
 120 extern int sysctl_ieee_emulation_warnings;
 121 #endif
 122 extern int sysctl_userprocess_debug;
 123 extern int spin_retry;
 124 #endif
 125
 126 extern int sysctl_hz_timer;
 127
 128 #ifdef CONFIG_BSD_PROCESS_ACCT
 129 extern int acct_parm[];
 130 #endif
 131
 132 #ifdef CONFIG_IA64
 133 extern int no_unaligned_warning;
 134 #endif
 135
 136 #ifdef CONFIG_RT_MUTEXES
 137 extern int max_lock_depth;
 138 #endif
 139
 140 static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
 141                        ctl_table *, void **);
 142 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
 143                   void __user *buffer, size_t *lenp, loff_t *ppos);
 144
 145 static ctl_table root_table[];
 146 static struct ctl_table_header root_table_header =
 147         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 148
 149 static ctl_table kern_table[];
 150 static ctl_table vm_table[];
 151 static ctl_table fs_table[];
 152 static ctl_table debug_table[];
 153 static ctl_table dev_table[];
 154 extern ctl_table random_table[];
 155 #ifdef CONFIG_UNIX98_PTYS
 156 extern ctl_table pty_table[];
 157 #endif
 158 #ifdef CONFIG_INOTIFY_USER
 159 extern ctl_table inotify_table[];
 160 #endif
 161
 162 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 163 int sysctl_legacy_va_layout;
 164 #endif
 165
 166 /* /proc declarations: */
 167
 168 #ifdef CONFIG_PROC_FS
 169
 170 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
 171 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
 172 static int proc_opensys(struct inode *, struct file *);
 173
 174 struct file_operations proc_sys_file_operations = {
 175         .open           = proc_opensys,
 176         .read           = proc_readsys,
 177         .write          = proc_writesys,
 178 };
 179
 180 extern struct proc_dir_entry *proc_sys_root;
 181
 182 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
 183 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
 184 #endif
 185
 186 /* The default sysctl tables: */
 187
 188 static ctl_table root_table[] = {
 189         {
 190                 .ctl_name       = CTL_KERN,
 191                 .procname       = "kernel",
 192                 .mode           = 0555,
 193                 .child          = kern_table,
 194         },
 195         {
 196                 .ctl_name       = CTL_VM,
 197                 .procname       = "vm",
 198                 .mode           = 0555,
 199                 .child          = vm_table,
 200         },
 201 #ifdef CONFIG_NET
 202         {
 203                 .ctl_name       = CTL_NET,
 204                 .procname       = "net",
 205                 .mode           = 0555,
 206                 .child          = net_table,
 207         },
 208 #endif
 209         {
 210                 .ctl_name       = CTL_FS,
 211                 .procname       = "fs",
 212                 .mode           = 0555,
 213                 .child          = fs_table,
 214         },
 215         {
 216                 .ctl_name       = CTL_DEBUG,
 217                 .procname       = "debug",
 218                 .mode           = 0555,
 219                 .child          = debug_table,
 220         },
 221         {
 222                 .ctl_name       = CTL_DEV,
 223                 .procname       = "dev",
 224                 .mode           = 0555,
 225                 .child          = dev_table,
 226         },
 227
 228         { .ctl_name = 0 }
 229 };
 230
 231 static ctl_table kern_table[] = {
 232         {
 233                 .ctl_name       = KERN_OSTYPE,
 234                 .procname       = "ostype",
 235                 .data           = system_utsname.sysname,
 236                 .maxlen         = sizeof(system_utsname.sysname),
 237                 .mode           = 0444,
 238                 .proc_handler   = &proc_doutsstring,
 239                 .strategy       = &sysctl_string,
 240         },
 241         {
 242                 .ctl_name       = KERN_OSRELEASE,
 243                 .procname       = "osrelease",
 244                 .data           = system_utsname.release,
 245                 .maxlen         = sizeof(system_utsname.release),
 246                 .mode           = 0444,
 247                 .proc_handler   = &proc_doutsstring,
 248                 .strategy       = &sysctl_string,
 249         },
 250         {
 251                 .ctl_name       = KERN_VERSION,
 252                 .procname       = "version",
 253                 .data           = system_utsname.version,
 254                 .maxlen         = sizeof(system_utsname.version),
 255                 .mode           = 0444,
 256                 .proc_handler   = &proc_doutsstring,
 257                 .strategy       = &sysctl_string,
 258         },
 259         {
 260                 .ctl_name       = KERN_NODENAME,
 261                 .procname       = "hostname",
 262                 .data           = system_utsname.nodename,
 263                 .maxlen         = sizeof(system_utsname.nodename),
 264                 .mode           = 0644,
 265                 .proc_handler   = &proc_doutsstring,
 266                 .strategy       = &sysctl_string,
 267         },
 268         {
 269                 .ctl_name       = KERN_DOMAINNAME,
 270                 .procname       = "domainname",
 271                 .data           = system_utsname.domainname,
 272                 .maxlen         = sizeof(system_utsname.domainname),
 273                 .mode           = 0644,
 274                 .proc_handler   = &proc_doutsstring,
 275                 .strategy       = &sysctl_string,
 276         },
 277         {
 278                 .ctl_name       = KERN_PANIC,
 279                 .procname       = "panic",
 280                 .data           = &panic_timeout,
 281                 .maxlen         = sizeof(int),
 282                 .mode           = 0644,
 283                 .proc_handler   = &proc_dointvec,
 284         },
 285         {
 286                 .ctl_name       = KERN_CORE_USES_PID,
 287                 .procname       = "core_uses_pid",
 288                 .data           = &core_uses_pid,
 289                 .maxlen         = sizeof(int),
 290                 .mode           = 0644,
 291                 .proc_handler   = &proc_dointvec,
 292         },
 293         {
 294                 .ctl_name       = KERN_CORE_PATTERN,
 295                 .procname       = "core_pattern",
 296                 .data           = core_pattern,
 297                 .maxlen         = 64,
 298                 .mode           = 0644,
 299                 .proc_handler   = &proc_dostring,
 300                 .strategy       = &sysctl_string,
 301         },
 302         {
 303                 .ctl_name       = KERN_TAINTED,
 304                 .procname       = "tainted",
 305                 .data           = &tainted,
 306                 .maxlen         = sizeof(int),
 307                 .mode           = 0444,
 308                 .proc_handler   = &proc_dointvec,
 309         },
 310         {
 311                 .ctl_name       = KERN_CAP_BSET,
 312                 .procname       = "cap-bound",
 313                 .data           = &cap_bset,
 314                 .maxlen         = sizeof(kernel_cap_t),
 315                 .mode           = 0600,
 316                 .proc_handler   = &proc_dointvec_bset,
 317         },
 318 #ifdef CONFIG_BLK_DEV_INITRD
 319         {
 320                 .ctl_name       = KERN_REALROOTDEV,
 321                 .procname       = "real-root-dev",
 322                 .data           = &real_root_dev,
 323                 .maxlen         = sizeof(int),
 324                 .mode           = 0644,
 325                 .proc_handler   = &proc_dointvec,
 326         },
 327 #endif
 328 #ifdef __sparc__
 329         {
 330                 .ctl_name       = KERN_SPARC_REBOOT,
 331                 .procname       = "reboot-cmd",
 332                 .data           = reboot_command,
 333                 .maxlen         = 256,
 334                 .mode           = 0644,
 335                 .proc_handler   = &proc_dostring,
 336                 .strategy       = &sysctl_string,
 337         },
 338         {
 339                 .ctl_name       = KERN_SPARC_STOP_A,
 340                 .procname       = "stop-a",
 341                 .data           = &stop_a_enabled,
 342                 .maxlen         = sizeof (int),
 343                 .mode           = 0644,
 344                 .proc_handler   = &proc_dointvec,
 345         },
 346         {
 347                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 348                 .procname       = "scons-poweroff",
 349                 .data           = &scons_pwroff,
 350                 .maxlen         = sizeof (int),
 351                 .mode           = 0644,
 352                 .proc_handler   = &proc_dointvec,
 353         },
 354 #endif
 355 #ifdef __hppa__
 356         {
 357                 .ctl_name       = KERN_HPPA_PWRSW,
 358                 .procname       = "soft-power",
 359                 .data           = &pwrsw_enabled,
 360                 .maxlen         = sizeof (int),
 361                 .mode           = 0644,
 362                 .proc_handler   = &proc_dointvec,
 363         },
 364         {
 365                 .ctl_name       = KERN_HPPA_UNALIGNED,
 366                 .procname       = "unaligned-trap",
 367                 .data           = &unaligned_enabled,
 368                 .maxlen         = sizeof (int),
 369                 .mode           = 0644,
 370                 .proc_handler   = &proc_dointvec,
 371         },
 372 #endif
 373         {
 374                 .ctl_name       = KERN_CTLALTDEL,
 375                 .procname       = "ctrl-alt-del",
 376                 .data           = &C_A_D,
 377                 .maxlen         = sizeof(int),
 378                 .mode           = 0644,
 379                 .proc_handler   = &proc_dointvec,
 380         },
 381         {
 382                 .ctl_name       = KERN_PRINTK,
 383                 .procname       = "printk",
 384                 .data           = &console_loglevel,
 385                 .maxlen         = 4*sizeof(int),
 386                 .mode           = 0644,
 387                 .proc_handler   = &proc_dointvec,
 388         },
 389 #ifdef CONFIG_KMOD
 390         {
 391                 .ctl_name       = KERN_MODPROBE,
 392                 .procname       = "modprobe",
 393                 .data           = &modprobe_path,
 394                 .maxlen         = KMOD_PATH_LEN,
 395                 .mode           = 0644,
 396                 .proc_handler   = &proc_dostring,
 397                 .strategy       = &sysctl_string,
 398         },
 399 #endif
 400 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 401         {
 402                 .ctl_name       = KERN_HOTPLUG,
 403                 .procname       = "hotplug",
 404                 .data           = &uevent_helper,
 405                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_dostring,
 408                 .strategy       = &sysctl_string,
 409         },
 410 #endif
 411 #ifdef CONFIG_CHR_DEV_SG
 412         {
 413                 .ctl_name       = KERN_SG_BIG_BUFF,
 414                 .procname       = "sg-big-buff",
 415                 .data           = &sg_big_buff,
 416                 .maxlen         = sizeof (int),
 417                 .mode           = 0444,
 418                 .proc_handler   = &proc_dointvec,
 419         },
 420 #endif
 421 #ifdef CONFIG_BSD_PROCESS_ACCT
 422         {
 423                 .ctl_name       = KERN_ACCT,
 424                 .procname       = "acct",
 425                 .data           = &acct_parm,
 426                 .maxlen         = 3*sizeof(int),
 427                 .mode           = 0644,
 428                 .proc_handler   = &proc_dointvec,
 429         },
 430 #endif
 431 #ifdef CONFIG_SYSVIPC
 432         {
 433                 .ctl_name       = KERN_SHMMAX,
 434                 .procname       = "shmmax",
 435                 .data           = &shm_ctlmax,
 436                 .maxlen         = sizeof (size_t),
 437                 .mode           = 0644,
 438                 .proc_handler   = &proc_doulongvec_minmax,
 439         },
 440         {
 441                 .ctl_name       = KERN_SHMALL,
 442                 .procname       = "shmall",
 443                 .data           = &shm_ctlall,
 444                 .maxlen         = sizeof (size_t),
 445                 .mode           = 0644,
 446                 .proc_handler   = &proc_doulongvec_minmax,
 447         },
 448         {
 449                 .ctl_name       = KERN_SHMMNI,
 450                 .procname       = "shmmni",
 451                 .data           = &shm_ctlmni,
 452                 .maxlen         = sizeof (int),
 453                 .mode           = 0644,
 454                 .proc_handler   = &proc_dointvec,
 455         },
 456         {
 457                 .ctl_name       = KERN_MSGMAX,
 458                 .procname       = "msgmax",
 459                 .data           = &msg_ctlmax,
 460                 .maxlen         = sizeof (int),
 461                 .mode           = 0644,
 462                 .proc_handler   = &proc_dointvec,
 463         },
 464         {
 465                 .ctl_name       = KERN_MSGMNI,
 466                 .procname       = "msgmni",
 467                 .data           = &msg_ctlmni,
 468                 .maxlen         = sizeof (int),
 469                 .mode           = 0644,
 470                 .proc_handler   = &proc_dointvec,
 471         },
 472         {
 473                 .ctl_name       = KERN_MSGMNB,
 474                 .procname       =  "msgmnb",
 475                 .data           = &msg_ctlmnb,
 476                 .maxlen         = sizeof (int),
 477                 .mode           = 0644,
 478                 .proc_handler   = &proc_dointvec,
 479         },
 480         {
 481                 .ctl_name       = KERN_SEM,
 482                 .procname       = "sem",
 483                 .data           = &sem_ctls,
 484                 .maxlen         = 4*sizeof (int),
 485                 .mode           = 0644,
 486                 .proc_handler   = &proc_dointvec,
 487         },
 488 #endif
 489 #ifdef CONFIG_MAGIC_SYSRQ
 490         {
 491                 .ctl_name       = KERN_SYSRQ,
 492                 .procname       = "sysrq",
 493                 .data           = &sysrq_enabled,
 494                 .maxlen         = sizeof (int),
 495                 .mode           = 0644,
 496                 .proc_handler   = &proc_dointvec,
 497         },
 498 #endif
 499         {
 500                 .ctl_name       = KERN_CADPID,
 501                 .procname       = "cad_pid",
 502                 .data           = &cad_pid,
 503                 .maxlen         = sizeof (int),
 504                 .mode           = 0600,
 505                 .proc_handler   = &proc_dointvec,
 506         },
 507         {
 508                 .ctl_name       = KERN_MAX_THREADS,
 509                 .procname       = "threads-max",
 510                 .data           = &max_threads,
 511                 .maxlen         = sizeof(int),
 512                 .mode           = 0644,
 513                 .proc_handler   = &proc_dointvec,
 514         },
 515         {
 516                 .ctl_name       = KERN_RANDOM,
 517                 .procname       = "random",
 518                 .mode           = 0555,
 519                 .child          = random_table,
 520         },
 521 #ifdef CONFIG_UNIX98_PTYS
 522         {
 523                 .ctl_name       = KERN_PTY,
 524                 .procname       = "pty",
 525                 .mode           = 0555,
 526                 .child          = pty_table,
 527         },
 528 #endif
 529         {
 530                 .ctl_name       = KERN_OVERFLOWUID,
 531                 .procname       = "overflowuid",
 532                 .data           = &overflowuid,
 533                 .maxlen         = sizeof(int),
 534                 .mode           = 0644,
 535                 .proc_handler   = &proc_dointvec_minmax,
 536                 .strategy       = &sysctl_intvec,
 537                 .extra1         = &minolduid,
 538                 .extra2         = &maxolduid,
 539         },
 540         {
 541                 .ctl_name       = KERN_OVERFLOWGID,
 542                 .procname       = "overflowgid",
 543                 .data           = &overflowgid,
 544                 .maxlen         = sizeof(int),
 545                 .mode           = 0644,
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .strategy       = &sysctl_intvec,
 548                 .extra1         = &minolduid,
 549                 .extra2         = &maxolduid,
 550         },
 551 #ifdef CONFIG_S390
 552 #ifdef CONFIG_MATHEMU
 553         {
 554                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 555                 .procname       = "ieee_emulation_warnings",
 556                 .data           = &sysctl_ieee_emulation_warnings,
 557                 .maxlen         = sizeof(int),
 558                 .mode           = 0644,
 559                 .proc_handler   = &proc_dointvec,
 560         },
 561 #endif
 562 #ifdef CONFIG_NO_IDLE_HZ
 563         {
 564                 .ctl_name       = KERN_HZ_TIMER,
 565                 .procname       = "hz_timer",
 566                 .data           = &sysctl_hz_timer,
 567                 .maxlen         = sizeof(int),
 568                 .mode           = 0644,
 569                 .proc_handler   = &proc_dointvec,
 570         },
 571 #endif
 572         {
 573                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 574                 .procname       = "userprocess_debug",
 575                 .data           = &sysctl_userprocess_debug,
 576                 .maxlen         = sizeof(int),
 577                 .mode           = 0644,
 578                 .proc_handler   = &proc_dointvec,
 579         },
 580 #endif
 581         {
 582                 .ctl_name       = KERN_PIDMAX,
 583                 .procname       = "pid_max",
 584                 .data           = &pid_max,
 585                 .maxlen         = sizeof (int),
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dointvec_minmax,
 588                 .strategy       = sysctl_intvec,
 589                 .extra1         = &pid_max_min,
 590                 .extra2         = &pid_max_max,
 591         },
 592         {
 593                 .ctl_name       = KERN_PANIC_ON_OOPS,
 594                 .procname       = "panic_on_oops",
 595                 .data           = &panic_on_oops,
 596                 .maxlen         = sizeof(int),
 597                 .mode           = 0644,
 598                 .proc_handler   = &proc_dointvec,
 599         },
 600         {
 601                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 602                 .procname       = "printk_ratelimit",
 603                 .data           = &printk_ratelimit_jiffies,
 604                 .maxlen         = sizeof(int),
 605                 .mode           = 0644,
 606                 .proc_handler   = &proc_dointvec_jiffies,
 607                 .strategy       = &sysctl_jiffies,
 608         },
 609         {
 610                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 611                 .procname       = "printk_ratelimit_burst",
 612                 .data           = &printk_ratelimit_burst,
 613                 .maxlen         = sizeof(int),
 614                 .mode           = 0644,
 615                 .proc_handler   = &proc_dointvec,
 616         },
 617         {
 618                 .ctl_name       = KERN_NGROUPS_MAX,
 619                 .procname       = "ngroups_max",
 620                 .data           = &ngroups_max,
 621                 .maxlen         = sizeof (int),
 622                 .mode           = 0444,
 623                 .proc_handler   = &proc_dointvec,
 624         },
 625 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 626         {
 627                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 628                 .procname       = "unknown_nmi_panic",
 629                 .data           = &unknown_nmi_panic,
 630                 .maxlen         = sizeof (int),
 631                 .mode           = 0644,
 632                 .proc_handler   = &proc_unknown_nmi_panic,
 633         },
 634 #endif
 635 #if defined(CONFIG_X86)
 636         {
 637                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 638                 .procname       = "bootloader_type",
 639                 .data           = &bootloader_type,
 640                 .maxlen         = sizeof (int),
 641                 .mode           = 0444,
 642                 .proc_handler   = &proc_dointvec,
 643         },
 644 #endif
 645 #if defined(CONFIG_MMU)
 646         {
 647                 .ctl_name       = KERN_RANDOMIZE,
 648                 .procname       = "randomize_va_space",
 649                 .data           = &randomize_va_space,
 650                 .maxlen         = sizeof(int),
 651                 .mode           = 0644,
 652                 .proc_handler   = &proc_dointvec,
 653         },
 654 #endif
 655 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 656         {
 657                 .ctl_name       = KERN_SPIN_RETRY,
 658                 .procname       = "spin_retry",
 659                 .data           = &spin_retry,
 660                 .maxlen         = sizeof (int),
 661                 .mode           = 0644,
 662                 .proc_handler   = &proc_dointvec,
 663         },
 664 #endif
 665 #ifdef CONFIG_ACPI_SLEEP
 666         {
 667                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 668                 .procname       = "acpi_video_flags",
 669                 .data           = &acpi_video_flags,
 670                 .maxlen         = sizeof (unsigned long),
 671                 .mode           = 0644,
 672                 .proc_handler   = &proc_doulongvec_minmax,
 673         },
 674 #endif
 675 #ifdef CONFIG_IA64
 676         {
 677                 .ctl_name       = KERN_IA64_UNALIGNED,
 678                 .procname       = "ignore-unaligned-usertrap",
 679                 .data           = &no_unaligned_warning,
 680                 .maxlen         = sizeof (int),
 681                 .mode           = 0644,
 682                 .proc_handler   = &proc_dointvec,
 683         },
 684 #endif
 685 #ifdef CONFIG_COMPAT
 686         {
 687                 .ctl_name       = KERN_COMPAT_LOG,
 688                 .procname       = "compat-log",
 689                 .data           = &compat_log,
 690                 .maxlen         = sizeof (int),
 691                 .mode           = 0644,
 692                 .proc_handler   = &proc_dointvec,
 693         },
 694 #endif
 695 #ifdef CONFIG_RT_MUTEXES
 696         {
 697                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 698                 .procname       = "max_lock_depth",
 699                 .data           = &max_lock_depth,
 700                 .maxlen         = sizeof(int),
 701                 .mode           = 0644,
 702                 .proc_handler   = &proc_dointvec,
 703         },
 704 #endif
 705
 706         { .ctl_name = 0 }
 707 };
 708
 709 /* Constants for minimum and maximum testing in vm_table.
 710    We use these as one-element integer vectors. */
 711 static int zero;
 712 static int one_hundred = 100;
 713
 714
 715 static ctl_table vm_table[] = {
 716         {
 717                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 718                 .procname       = "overcommit_memory",
 719                 .data           = &sysctl_overcommit_memory,
 720                 .maxlen         = sizeof(sysctl_overcommit_memory),
 721                 .mode           = 0644,
 722                 .proc_handler   = &proc_dointvec,
 723         },
 724         {
 725                 .ctl_name       = VM_PANIC_ON_OOM,
 726                 .procname       = "panic_on_oom",
 727                 .data           = &sysctl_panic_on_oom,
 728                 .maxlen         = sizeof(sysctl_panic_on_oom),
 729                 .mode           = 0644,
 730                 .proc_handler   = &proc_dointvec,
 731         },
 732         {
 733                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 734                 .procname       = "overcommit_ratio",
 735                 .data           = &sysctl_overcommit_ratio,
 736                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 737                 .mode           = 0644,
 738                 .proc_handler   = &proc_dointvec,
 739         },
 740         {
 741                 .ctl_name       = VM_PAGE_CLUSTER,
 742                 .procname       = "page-cluster",
 743                 .data           = &page_cluster,
 744                 .maxlen         = sizeof(int),
 745                 .mode           = 0644,
 746                 .proc_handler   = &proc_dointvec,
 747         },
 748         {
 749                 .ctl_name       = VM_DIRTY_BACKGROUND,
 750                 .procname       = "dirty_background_ratio",
 751                 .data           = &dirty_background_ratio,
 752                 .maxlen         = sizeof(dirty_background_ratio),
 753                 .mode           = 0644,
 754                 .proc_handler   = &proc_dointvec_minmax,
 755                 .strategy       = &sysctl_intvec,
 756                 .extra1         = &zero,
 757                 .extra2         = &one_hundred,
 758         },
 759         {
 760                 .ctl_name       = VM_DIRTY_RATIO,
 761                 .procname       = "dirty_ratio",
 762                 .data           = &vm_dirty_ratio,
 763                 .maxlen         = sizeof(vm_dirty_ratio),
 764                 .mode           = 0644,
 765                 .proc_handler   = &proc_dointvec_minmax,
 766                 .strategy       = &sysctl_intvec,
 767                 .extra1         = &zero,
 768                 .extra2         = &one_hundred,
 769         },
 770         {
 771                 .ctl_name       = VM_DIRTY_WB_CS,
 772                 .procname       = "dirty_writeback_centisecs",
 773                 .data           = &dirty_writeback_interval,
 774                 .maxlen         = sizeof(dirty_writeback_interval),
 775                 .mode           = 0644,
 776                 .proc_handler   = &dirty_writeback_centisecs_handler,
 777         },
 778         {
 779                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 780                 .procname       = "dirty_expire_centisecs",
 781                 .data           = &dirty_expire_interval,
 782                 .maxlen         = sizeof(dirty_expire_interval),
 783                 .mode           = 0644,
 784                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 785         },
 786         {
 787                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 788                 .procname       = "nr_pdflush_threads",
 789                 .data           = &nr_pdflush_threads,
 790                 .maxlen         = sizeof nr_pdflush_threads,
 791                 .mode           = 0444 /* read-only*/,
 792                 .proc_handler   = &proc_dointvec,
 793         },
 794         {
 795                 .ctl_name       = VM_SWAPPINESS,
 796                 .procname       = "swappiness",
 797                 .data           = &vm_swappiness,
 798                 .maxlen         = sizeof(vm_swappiness),
 799                 .mode           = 0644,
 800                 .proc_handler   = &proc_dointvec_minmax,
 801                 .strategy       = &sysctl_intvec,
 802                 .extra1         = &zero,
 803                 .extra2         = &one_hundred,
 804         },
 805 #ifdef CONFIG_HUGETLB_PAGE
 806          {
 807                 .ctl_name       = VM_HUGETLB_PAGES,
 808                 .procname       = "nr_hugepages",
 809                 .data           = &max_huge_pages,
 810                 .maxlen         = sizeof(unsigned long),
 811                 .mode           = 0644,
 812                 .proc_handler   = &hugetlb_sysctl_handler,
 813                 .extra1         = (void *)&hugetlb_zero,
 814                 .extra2         = (void *)&hugetlb_infinity,
 815          },
 816          {
 817                 .ctl_name       = VM_HUGETLB_GROUP,
 818                 .procname       = "hugetlb_shm_group",
 819                 .data           = &sysctl_hugetlb_shm_group,
 820                 .maxlen         = sizeof(gid_t),
 821                 .mode           = 0644,
 822                 .proc_handler   = &proc_dointvec,
 823          },
 824 #endif
 825         {
 826                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 827                 .procname       = "lowmem_reserve_ratio",
 828                 .data           = &sysctl_lowmem_reserve_ratio,
 829                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 830                 .mode           = 0644,
 831                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 832                 .strategy       = &sysctl_intvec,
 833         },
 834         {
 835                 .ctl_name       = VM_DROP_PAGECACHE,
 836                 .procname       = "drop_caches",
 837                 .data           = &sysctl_drop_caches,
 838                 .maxlen         = sizeof(int),
 839                 .mode           = 0644,
 840                 .proc_handler   = drop_caches_sysctl_handler,
 841                 .strategy       = &sysctl_intvec,
 842         },
 843         {
 844                 .ctl_name       = VM_MIN_FREE_KBYTES,
 845                 .procname       = "min_free_kbytes",
 846                 .data           = &min_free_kbytes,
 847                 .maxlen         = sizeof(min_free_kbytes),
 848                 .mode           = 0644,
 849                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 850                 .strategy       = &sysctl_intvec,
 851                 .extra1         = &zero,
 852         },
 853         {
 854                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 855                 .procname       = "percpu_pagelist_fraction",
 856                 .data           = &percpu_pagelist_fraction,
 857                 .maxlen         = sizeof(percpu_pagelist_fraction),
 858                 .mode           = 0644,
 859                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 860                 .strategy       = &sysctl_intvec,
 861                 .extra1         = &min_percpu_pagelist_fract,
 862         },
 863 #ifdef CONFIG_MMU
 864         {
 865                 .ctl_name       = VM_MAX_MAP_COUNT,
 866                 .procname       = "max_map_count",
 867                 .data           = &sysctl_max_map_count,
 868                 .maxlen         = sizeof(sysctl_max_map_count),
 869                 .mode           = 0644,
 870                 .proc_handler   = &proc_dointvec
 871         },
 872 #endif
 873         {
 874                 .ctl_name       = VM_LAPTOP_MODE,
 875                 .procname       = "laptop_mode",
 876                 .data           = &laptop_mode,
 877                 .maxlen         = sizeof(laptop_mode),
 878                 .mode           = 0644,
 879                 .proc_handler   = &proc_dointvec_jiffies,
 880                 .strategy       = &sysctl_jiffies,
 881         },
 882         {
 883                 .ctl_name       = VM_BLOCK_DUMP,
 884                 .procname       = "block_dump",
 885                 .data           = &block_dump,
 886                 .maxlen         = sizeof(block_dump),
 887                 .mode           = 0644,
 888                 .proc_handler   = &proc_dointvec,
 889                 .strategy       = &sysctl_intvec,
 890                 .extra1         = &zero,
 891         },
 892         {
 893                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 894                 .procname       = "vfs_cache_pressure",
 895                 .data           = &sysctl_vfs_cache_pressure,
 896                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 897                 .mode           = 0644,
 898                 .proc_handler   = &proc_dointvec,
 899                 .strategy       = &sysctl_intvec,
 900                 .extra1         = &zero,
 901         },
 902 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 903         {
 904                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 905                 .procname       = "legacy_va_layout",
 906                 .data           = &sysctl_legacy_va_layout,
 907                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 908                 .mode           = 0644,
 909                 .proc_handler   = &proc_dointvec,
 910                 .strategy       = &sysctl_intvec,
 911                 .extra1         = &zero,
 912         },
 913 #endif
 914 #ifdef CONFIG_SWAP
 915         {
 916                 .ctl_name       = VM_SWAP_TOKEN_TIMEOUT,
 917                 .procname       = "swap_token_timeout",
 918                 .data           = &swap_token_default_timeout,
 919                 .maxlen         = sizeof(swap_token_default_timeout),
 920                 .mode           = 0644,
 921                 .proc_handler   = &proc_dointvec_jiffies,
 922                 .strategy       = &sysctl_jiffies,
 923         },
 924 #endif
 925 #ifdef CONFIG_NUMA
 926         {
 927                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 928                 .procname       = "zone_reclaim_mode",
 929                 .data           = &zone_reclaim_mode,
 930                 .maxlen         = sizeof(zone_reclaim_mode),
 931                 .mode           = 0644,
 932                 .proc_handler   = &proc_dointvec,
 933                 .strategy       = &sysctl_intvec,
 934                 .extra1         = &zero,
 935         },
 936 #endif
 937 #ifdef CONFIG_X86_32
 938         {
 939                 .ctl_name       = VM_VDSO_ENABLED,
 940                 .procname       = "vdso_enabled",
 941                 .data           = &vdso_enabled,
 942                 .maxlen         = sizeof(vdso_enabled),
 943                 .mode           = 0644,
 944                 .proc_handler   = &proc_dointvec,
 945                 .strategy       = &sysctl_intvec,
 946                 .extra1         = &zero,
 947         },
 948 #endif
 949         { .ctl_name = 0 }
 950 };
 951
 952 static ctl_table fs_table[] = {
 953         {
 954                 .ctl_name       = FS_NRINODE,
 955                 .procname       = "inode-nr",
 956                 .data           = &inodes_stat,
 957                 .maxlen         = 2*sizeof(int),
 958                 .mode           = 0444,
 959                 .proc_handler   = &proc_dointvec,
 960         },
 961         {
 962                 .ctl_name       = FS_STATINODE,
 963                 .procname       = "inode-state",
 964                 .data           = &inodes_stat,
 965                 .maxlen         = 7*sizeof(int),
 966                 .mode           = 0444,
 967                 .proc_handler   = &proc_dointvec,
 968         },
 969         {
 970                 .ctl_name       = FS_NRFILE,
 971                 .procname       = "file-nr",
 972                 .data           = &files_stat,
 973                 .maxlen         = 3*sizeof(int),
 974                 .mode           = 0444,
 975                 .proc_handler   = &proc_nr_files,
 976         },
 977         {
 978                 .ctl_name       = FS_MAXFILE,
 979                 .procname       = "file-max",
 980                 .data           = &files_stat.max_files,
 981                 .maxlen         = sizeof(int),
 982                 .mode           = 0644,
 983                 .proc_handler   = &proc_dointvec,
 984         },
 985         {
 986                 .ctl_name       = FS_DENTRY,
 987                 .procname       = "dentry-state",
 988                 .data           = &dentry_stat,
 989                 .maxlen         = 6*sizeof(int),
 990                 .mode           = 0444,
 991                 .proc_handler   = &proc_dointvec,
 992         },
 993         {
 994                 .ctl_name       = FS_OVERFLOWUID,
 995                 .procname       = "overflowuid",
 996                 .data           = &fs_overflowuid,
 997                 .maxlen         = sizeof(int),
 998                 .mode           = 0644,
 999                 .proc_handler   = &proc_dointvec_minmax,
1000                 .strategy       = &sysctl_intvec,
1001                 .extra1         = &minolduid,
1002                 .extra2         = &maxolduid,
1003         },
1004         {
1005                 .ctl_name       = FS_OVERFLOWGID,
1006                 .procname       = "overflowgid",
1007                 .data           = &fs_overflowgid,
1008                 .maxlen         = sizeof(int),
1009                 .mode           = 0644,
1010                 .proc_handler   = &proc_dointvec_minmax,
1011                 .strategy       = &sysctl_intvec,
1012                 .extra1         = &minolduid,
1013                 .extra2         = &maxolduid,
1014         },
1015         {
1016                 .ctl_name       = FS_LEASES,
1017                 .procname       = "leases-enable",
1018                 .data           = &leases_enable,
1019                 .maxlen         = sizeof(int),
1020                 .mode           = 0644,
1021                 .proc_handler   = &proc_dointvec,
1022         },
1023 #ifdef CONFIG_DNOTIFY
1024         {
1025                 .ctl_name       = FS_DIR_NOTIFY,
1026                 .procname       = "dir-notify-enable",
1027                 .data           = &dir_notify_enable,
1028                 .maxlen         = sizeof(int),
1029                 .mode           = 0644,
1030                 .proc_handler   = &proc_dointvec,
1031         },
1032 #endif
1033 #ifdef CONFIG_MMU
1034         {
1035                 .ctl_name       = FS_LEASE_TIME,
1036                 .procname       = "lease-break-time",
1037                 .data           = &lease_break_time,
1038                 .maxlen         = sizeof(int),
1039                 .mode           = 0644,
1040                 .proc_handler   = &proc_dointvec,
1041         },
1042         {
1043                 .ctl_name       = FS_AIO_NR,
1044                 .procname       = "aio-nr",
1045                 .data           = &aio_nr,
1046                 .maxlen         = sizeof(aio_nr),
1047                 .mode           = 0444,
1048                 .proc_handler   = &proc_doulongvec_minmax,
1049         },
1050         {
1051                 .ctl_name       = FS_AIO_MAX_NR,
1052                 .procname       = "aio-max-nr",
1053                 .data           = &aio_max_nr,
1054                 .maxlen         = sizeof(aio_max_nr),
1055                 .mode           = 0644,
1056                 .proc_handler   = &proc_doulongvec_minmax,
1057         },
1058 #ifdef CONFIG_INOTIFY_USER
1059         {
1060                 .ctl_name       = FS_INOTIFY,
1061                 .procname       = "inotify",
1062                 .mode           = 0555,
1063                 .child          = inotify_table,
1064         },
1065 #endif
1066 #endif
1067         {
1068                 .ctl_name       = KERN_SETUID_DUMPABLE,
1069                 .procname       = "suid_dumpable",
1070                 .data           = &suid_dumpable,
1071                 .maxlen         = sizeof(int),
1072                 .mode           = 0644,
1073                 .proc_handler   = &proc_dointvec,
1074         },
1075         { .ctl_name = 0 }
1076 };
1077
1078 static ctl_table debug_table[] = {
1079         { .ctl_name = 0 }
1080 };
1081
1082 static ctl_table dev_table[] = {
1083         { .ctl_name = 0 }
1084 };
1085
1086 extern void init_irq_proc (void);
1087
1088 static DEFINE_SPINLOCK(sysctl_lock);
1089
1090 /* called under sysctl_lock */
1091 static int use_table(struct ctl_table_header *p)
1092 {
1093         if (unlikely(p->unregistering))
1094                 return 0;
1095         p->used++;
1096         return 1;
1097 }
1098
1099 /* called under sysctl_lock */
1100 static void unuse_table(struct ctl_table_header *p)
1101 {
1102         if (!--p->used)
1103                 if (unlikely(p->unregistering))
1104                         complete(p->unregistering);
1105 }
1106
1107 /* called under sysctl_lock, will reacquire if has to wait */
1108 static void start_unregistering(struct ctl_table_header *p)
1109 {
1110         /*
1111          * if p->used is 0, nobody will ever touch that entry again;
1112          * we'll eliminate all paths to it before dropping sysctl_lock
1113          */
1114         if (unlikely(p->used)) {
1115                 struct completion wait;
1116                 init_completion(&wait);
1117                 p->unregistering = &wait;
1118                 spin_unlock(&sysctl_lock);
1119                 wait_for_completion(&wait);
1120                 spin_lock(&sysctl_lock);
1121         }
1122         /*
1123          * do not remove from the list until nobody holds it; walking the
1124          * list in do_sysctl() relies on that.
1125          */
1126         list_del_init(&p->ctl_entry);
1127 }
1128
1129 void __init sysctl_init(void)
1130 {
1131 #ifdef CONFIG_PROC_FS
1132         register_proc_table(root_table, proc_sys_root, &root_table_header);
1133         init_irq_proc();
1134 #endif
1135 }
1136
1137 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1138                void __user *newval, size_t newlen)
1139 {
1140         struct list_head *tmp;
1141         int error = -ENOTDIR;
1142
1143         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1144                 return -ENOTDIR;
1145         if (oldval) {
1146                 int old_len;
1147                 if (!oldlenp || get_user(old_len, oldlenp))
1148                         return -EFAULT;
1149         }
1150         spin_lock(&sysctl_lock);
1151         tmp = &root_table_header.ctl_entry;
1152         do {
1153                 struct ctl_table_header *head =
1154                         list_entry(tmp, struct ctl_table_header, ctl_entry);
1155                 void *context = NULL;
1156
1157                 if (!use_table(head))
1158                         continue;
1159
1160                 spin_unlock(&sysctl_lock);
1161
1162                 error = parse_table(name, nlen, oldval, oldlenp,
1163                                         newval, newlen, head->ctl_table,
1164                                         &context);
1165                 kfree(context);
1166
1167                 spin_lock(&sysctl_lock);
1168                 unuse_table(head);
1169                 if (error != -ENOTDIR)
1170                         break;
1171         } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1172         spin_unlock(&sysctl_lock);
1173         return error;
1174 }
1175
1176 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1177 {
1178         struct __sysctl_args tmp;
1179         int error;
1180
1181         if (copy_from_user(&tmp, args, sizeof(tmp)))
1182                 return -EFAULT;
1183
1184         lock_kernel();
1185         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1186                           tmp.newval, tmp.newlen);
1187         unlock_kernel();
1188         return error;
1189 }
1190
1191 /*
1192  * ctl_perm does NOT grant the superuser all rights automatically, because
1193  * some sysctl variables are readonly even to root.
1194  */
1195
1196 static int test_perm(int mode, int op)
1197 {
1198         if (!current->euid)
1199                 mode >>= 6;
1200         else if (in_egroup_p(0))
1201                 mode >>= 3;
1202         if ((mode & op & 0007) == op)
1203                 return 0;
1204         return -EACCES;
1205 }
1206
1207 static inline int ctl_perm(ctl_table *table, int op)
1208 {
1209         int error;
1210         error = security_sysctl(table, op);
1211         if (error)
1212                 return error;
1213         return test_perm(table->mode, op);
1214 }
1215
1216 static int parse_table(int __user *name, int nlen,
1217                        void __user *oldval, size_t __user *oldlenp,
1218                        void __user *newval, size_t newlen,
1219                        ctl_table *table, void **context)
1220 {
1221         int n;
1222 repeat:
1223         if (!nlen)
1224                 return -ENOTDIR;
1225         if (get_user(n, name))
1226                 return -EFAULT;
1227         for ( ; table->ctl_name; table++) {
1228                 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1229                         int error;
1230                         if (table->child) {
1231                                 if (ctl_perm(table, 001))
1232                                         return -EPERM;
1233                                 if (table->strategy) {
1234                                         error = table->strategy(
1235                                                 table, name, nlen,
1236                                                 oldval, oldlenp,
1237                                                 newval, newlen, context);
1238                                         if (error)
1239                                                 return error;
1240                                 }
1241                                 name++;
1242                                 nlen--;
1243                                 table = table->child;
1244                                 goto repeat;
1245                         }
1246                         error = do_sysctl_strategy(table, name, nlen,
1247                                                    oldval, oldlenp,
1248                                                    newval, newlen, context);
1249                         return error;
1250                 }
1251         }
1252         return -ENOTDIR;
1253 }
1254
1255 /* Perform the actual read/write of a sysctl table entry. */
1256 int do_sysctl_strategy (ctl_table *table,
1257                         int __user *name, int nlen,
1258                         void __user *oldval, size_t __user *oldlenp,
1259                         void __user *newval, size_t newlen, void **context)
1260 {
1261         int op = 0, rc;
1262         size_t len;
1263
1264         if (oldval)
1265                 op |= 004;
1266         if (newval)
1267                 op |= 002;
1268         if (ctl_perm(table, op))
1269                 return -EPERM;
1270
1271         if (table->strategy) {
1272                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1273                                      newval, newlen, context);
1274                 if (rc < 0)
1275                         return rc;
1276                 if (rc > 0)
1277                         return 0;
1278         }
1279
1280         /* If there is no strategy routine, or if the strategy returns
1281          * zero, proceed with automatic r/w */
1282         if (table->data && table->maxlen) {
1283                 if (oldval && oldlenp) {
1284                         if (get_user(len, oldlenp))
1285                                 return -EFAULT;
1286                         if (len) {
1287                                 if (len > table->maxlen)
1288                                         len = table->maxlen;
1289                                 if(copy_to_user(oldval, table->data, len))
1290                                         return -EFAULT;
1291                                 if(put_user(len, oldlenp))
1292                                         return -EFAULT;
1293                         }
1294                 }
1295                 if (newval && newlen) {
1296                         len = newlen;
1297                         if (len > table->maxlen)
1298                                 len = table->maxlen;
1299                         if(copy_from_user(table->data, newval, len))
1300                                 return -EFAULT;
1301                 }
1302         }
1303         return 0;
1304 }
1305
1306 /**
1307  * register_sysctl_table - register a sysctl hierarchy
1308  * @table: the top-level table structure
1309  * @insert_at_head: whether the entry should be inserted in front or at the end
1310  *
1311  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1312  * array. An entry with a ctl_name of 0 terminates the table.
1313  *
1314  * The members of the &ctl_table structure are used as follows:
1315  *
1316  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1317  *            must be unique within that level of sysctl
1318  *
1319  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1320  *            enter a sysctl file
1321  *
1322  * data - a pointer to data for use by proc_handler
1323  *
1324  * maxlen - the maximum size in bytes of the data
1325  *
1326  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1327  *
1328  * child - a pointer to the child sysctl table if this entry is a directory, or
1329  *         %NULL.
1330  *
1331  * proc_handler - the text handler routine (described below)
1332  *
1333  * strategy - the strategy routine (described below)
1334  *
1335  * de - for internal use by the sysctl routines
1336  *
1337  * extra1, extra2 - extra pointers usable by the proc handler routines
1338  *
1339  * Leaf nodes in the sysctl tree will be represented by a single file
1340  * under /proc; non-leaf nodes will be represented by directories.
1341  *
1342  * sysctl(2) can automatically manage read and write requests through
1343  * the sysctl table.  The data and maxlen fields of the ctl_table
1344  * struct enable minimal validation of the values being written to be
1345  * performed, and the mode field allows minimal authentication.
1346  *
1347  * More sophisticated management can be enabled by the provision of a
1348  * strategy routine with the table entry.  This will be called before
1349  * any automatic read or write of the data is performed.
1350  *
1351  * The strategy routine may return
1352  *
1353  * < 0 - Error occurred (error is passed to user process)
1354  *
1355  * 0   - OK - proceed with automatic read or write.
1356  *
1357  * > 0 - OK - read or write has been done by the strategy routine, so
1358  *       return immediately.
1359  *
1360  * There must be a proc_handler routine for any terminal nodes
1361  * mirrored under /proc/sys (non-terminals are handled by a built-in
1362  * directory handler).  Several default handlers are available to
1363  * cover common cases -
1364  *
1365  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1366  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1367  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1368  *
1369  * It is the handler's job to read the input buffer from user memory
1370  * and process it. The handler should return 0 on success.
1371  *
1372  * This routine returns %NULL on a failure to register, and a pointer
1373  * to the table header on success.
1374  */
1375 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1376                                                int insert_at_head)
1377 {
1378         struct ctl_table_header *tmp;
1379         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1380         if (!tmp)
1381                 return NULL;
1382         tmp->ctl_table = table;
1383         INIT_LIST_HEAD(&tmp->ctl_entry);
1384         tmp->used = 0;
1385         tmp->unregistering = NULL;
1386         spin_lock(&sysctl_lock);
1387         if (insert_at_head)
1388                 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1389         else
1390                 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1391         spin_unlock(&sysctl_lock);
1392 #ifdef CONFIG_PROC_FS
1393         register_proc_table(table, proc_sys_root, tmp);
1394 #endif
1395         return tmp;
1396 }
1397
1398 /**
1399  * unregister_sysctl_table - unregister a sysctl table hierarchy
1400  * @header: the header returned from register_sysctl_table
1401  *
1402  * Unregisters the sysctl table and all children. proc entries may not
1403  * actually be removed until they are no longer used by anyone.
1404  */
1405 void unregister_sysctl_table(struct ctl_table_header * header)
1406 {
1407         might_sleep();
1408         spin_lock(&sysctl_lock);
1409         start_unregistering(header);
1410 #ifdef CONFIG_PROC_FS
1411         unregister_proc_table(header->ctl_table, proc_sys_root);
1412 #endif
1413         spin_unlock(&sysctl_lock);
1414         kfree(header);
1415 }
1416
1417 /*
1418  * /proc/sys support
1419  */
1420
1421 #ifdef CONFIG_PROC_FS
1422
1423 /* Scan the sysctl entries in table and add them all into /proc */
1424 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1425 {
1426         struct proc_dir_entry *de;
1427         int len;
1428         mode_t mode;
1429
1430         for (; table->ctl_name; table++) {
1431                 /* Can't do anything without a proc name. */
1432                 if (!table->procname)
1433                         continue;
1434                 /* Maybe we can't do anything with it... */
1435                 if (!table->proc_handler && !table->child) {
1436                         printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1437                                 table->procname);
1438                         continue;
1439                 }
1440
1441                 len = strlen(table->procname);
1442                 mode = table->mode;
1443
1444                 de = NULL;
1445                 if (table->proc_handler)
1446                         mode |= S_IFREG;
1447                 else {
1448                         mode |= S_IFDIR;
1449                         for (de = root->subdir; de; de = de->next) {
1450                                 if (proc_match(len, table->procname, de))
1451                                         break;
1452                         }
1453                         /* If the subdir exists already, de is non-NULL */
1454                 }
1455
1456                 if (!de) {
1457                         de = create_proc_entry(table->procname, mode, root);
1458                         if (!de)
1459                                 continue;
1460                         de->set = set;
1461                         de->data = (void *) table;
1462                         if (table->proc_handler)
1463                                 de->proc_fops = &proc_sys_file_operations;
1464                 }
1465                 table->de = de;
1466                 if (de->mode & S_IFDIR)
1467                         register_proc_table(table->child, de, set);
1468         }
1469 }
1470
1471 /*
1472  * Unregister a /proc sysctl table and any subdirectories.
1473  */
1474 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1475 {
1476         struct proc_dir_entry *de;
1477         for (; table->ctl_name; table++) {
1478                 if (!(de = table->de))
1479                         continue;
1480                 if (de->mode & S_IFDIR) {
1481                         if (!table->child) {
1482                                 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1483                                 continue;
1484                         }
1485                         unregister_proc_table(table->child, de);
1486
1487                         /* Don't unregister directories which still have entries.. */
1488                         if (de->subdir)
1489                                 continue;
1490                 }
1491
1492                 /*
1493                  * In any case, mark the entry as goner; we'll keep it
1494                  * around if it's busy, but we'll know to do nothing with
1495                  * its fields.  We are under sysctl_lock here.
1496                  */
1497                 de->data = NULL;
1498
1499                 /* Don't unregister proc entries that are still being used.. */
1500                 if (atomic_read(&de->count))
1501                         continue;
1502
1503                 table->de = NULL;
1504                 remove_proc_entry(table->procname, root);
1505         }
1506 }
1507
1508 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1509                           size_t count, loff_t *ppos)
1510 {
1511         int op;
1512         struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
1513         struct ctl_table *table;
1514         size_t res;
1515         ssize_t error = -ENOTDIR;
1516
1517         spin_lock(&sysctl_lock);
1518         if (de && de->data && use_table(de->set)) {
1519                 /*
1520                  * at that point we know that sysctl was not unregistered
1521                  * and won't be until we finish
1522                  */
1523                 spin_unlock(&sysctl_lock);
1524                 table = (struct ctl_table *) de->data;
1525                 if (!table || !table->proc_handler)
1526                         goto out;
1527                 error = -EPERM;
1528                 op = (write ? 002 : 004);
1529                 if (ctl_perm(table, op))
1530                         goto out;
1531
1532                 /* careful: calling conventions are nasty here */
1533                 res = count;
1534                 error = (*table->proc_handler)(table, write, file,
1535                                                 buf, &res, ppos);
1536                 if (!error)
1537                         error = res;
1538         out:
1539                 spin_lock(&sysctl_lock);
1540                 unuse_table(de->set);
1541         }
1542         spin_unlock(&sysctl_lock);
1543         return error;
1544 }
1545
1546 static int proc_opensys(struct inode *inode, struct file *file)
1547 {
1548         if (file->f_mode & FMODE_WRITE) {
1549                 /*
1550                  * sysctl entries that are not writable,
1551                  * are _NOT_ writable, capabilities or not.
1552                  */
1553                 if (!(inode->i_mode & S_IWUSR))
1554                         return -EPERM;
1555         }
1556
1557         return 0;
1558 }
1559
1560 static ssize_t proc_readsys(struct file * file, char __user * buf,
1561                             size_t count, loff_t *ppos)
1562 {
1563         return do_rw_proc(0, file, buf, count, ppos);
1564 }
1565
1566 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1567                              size_t count, loff_t *ppos)
1568 {
1569         return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1570 }
1571
1572 /**
1573  * proc_dostring - read a string sysctl
1574  * @table: the sysctl table
1575  * @write: %TRUE if this is a write to the sysctl file
1576  * @filp: the file structure
1577  * @buffer: the user buffer
1578  * @lenp: the size of the user buffer
1579  * @ppos: file position
1580  *
1581  * Reads/writes a string from/to the user buffer. If the kernel
1582  * buffer provided is not large enough to hold the string, the
1583  * string is truncated. The copied string is %NULL-terminated.
1584  * If the string is being read by the user process, it is copied
1585  * and a newline '\n' is added. It is truncated if the buffer is
1586  * not large enough.
1587  *
1588  * Returns 0 on success.
1589  */
1590 int proc_dostring(ctl_table *table, int write, struct file *filp,
1591                   void __user *buffer, size_t *lenp, loff_t *ppos)
1592 {
1593         size_t len;
1594         char __user *p;
1595         char c;
1596
1597         if (!table->data || !table->maxlen || !*lenp ||
1598             (*ppos && !write)) {
1599                 *lenp = 0;
1600                 return 0;
1601         }
1602
1603         if (write) {
1604                 len = 0;
1605                 p = buffer;
1606                 while (len < *lenp) {
1607                         if (get_user(c, p++))
1608                                 return -EFAULT;
1609                         if (c == 0 || c == '\n')
1610                                 break;
1611                         len++;
1612                 }
1613                 if (len >= table->maxlen)
1614                         len = table->maxlen-1;
1615                 if(copy_from_user(table->data, buffer, len))
1616                         return -EFAULT;
1617                 ((char *) table->data)[len] = 0;
1618                 *ppos += *lenp;
1619         } else {
1620                 len = strlen(table->data);
1621                 if (len > table->maxlen)
1622                         len = table->maxlen;
1623                 if (len > *lenp)
1624                         len = *lenp;
1625                 if (len)
1626                         if(copy_to_user(buffer, table->data, len))
1627                                 return -EFAULT;
1628                 if (len < *lenp) {
1629                         if(put_user('\n', ((char __user *) buffer) + len))
1630                                 return -EFAULT;
1631                         len++;
1632                 }
1633                 *lenp = len;
1634                 *ppos += len;
1635         }
1636         return 0;
1637 }
1638
1639 /*
1640  *      Special case of dostring for the UTS structure. This has locks
1641  *      to observe. Should this be in kernel/sys.c ????
1642  */
1643
1644 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1645                   void __user *buffer, size_t *lenp, loff_t *ppos)
1646 {
1647         int r;
1648
1649         if (!write) {
1650                 down_read(&uts_sem);
1651                 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1652                 up_read(&uts_sem);
1653         } else {
1654                 down_write(&uts_sem);
1655                 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1656                 up_write(&uts_sem);
1657         }
1658         return r;
1659 }
1660
1661 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1662                                  int *valp,
1663                                  int write, void *data)
1664 {
1665         if (write) {
1666                 *valp = *negp ? -*lvalp : *lvalp;
1667         } else {
1668                 int val = *valp;
1669                 if (val < 0) {
1670                         *negp = -1;
1671                         *lvalp = (unsigned long)-val;
1672                 } else {
1673                         *negp = 0;
1674                         *lvalp = (unsigned long)val;
1675                 }
1676         }
1677         return 0;
1678 }
1679
1680 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1681                   void __user *buffer, size_t *lenp, loff_t *ppos,
1682                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1683                               int write, void *data),
1684                   void *data)
1685 {
1686 #define TMPBUFLEN 21
1687         int *i, vleft, first=1, neg, val;
1688         unsigned long lval;
1689         size_t left, len;
1690
1691         char buf[TMPBUFLEN], *p;
1692         char __user *s = buffer;
1693
1694         if (!table->data || !table->maxlen || !*lenp ||
1695             (*ppos && !write)) {
1696                 *lenp = 0;
1697                 return 0;
1698         }
1699
1700         i = (int *) table->data;
1701         vleft = table->maxlen / sizeof(*i);
1702         left = *lenp;
1703
1704         if (!conv)
1705                 conv = do_proc_dointvec_conv;
1706
1707         for (; left && vleft--; i++, first=0) {
1708                 if (write) {
1709                         while (left) {
1710                                 char c;
1711                                 if (get_user(c, s))
1712                                         return -EFAULT;
1713                                 if (!isspace(c))
1714                                         break;
1715                                 left--;
1716                                 s++;
1717                         }
1718                         if (!left)
1719                                 break;
1720                         neg = 0;
1721                         len = left;
1722                         if (len > sizeof(buf) - 1)
1723                                 len = sizeof(buf) - 1;
1724                         if (copy_from_user(buf, s, len))
1725                                 return -EFAULT;
1726                         buf[len] = 0;
1727                         p = buf;
1728                         if (*p == '-' && left > 1) {
1729                                 neg = 1;
1730                                 left--, p++;
1731                         }
1732                         if (*p < '0' || *p > '9')
1733                                 break;
1734
1735                         lval = simple_strtoul(p, &p, 0);
1736
1737                         len = p-buf;
1738                         if ((len < left) && *p && !isspace(*p))
1739                                 break;
1740                         if (neg)
1741                                 val = -val;
1742                         s += len;
1743                         left -= len;
1744
1745                         if (conv(&neg, &lval, i, 1, data))
1746                                 break;
1747                 } else {
1748                         p = buf;
1749                         if (!first)
1750                                 *p++ = '\t';
1751
1752                         if (conv(&neg, &lval, i, 0, data))
1753                                 break;
1754
1755                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1756                         len = strlen(buf);
1757                         if (len > left)
1758                                 len = left;
1759                         if(copy_to_user(s, buf, len))
1760                                 return -EFAULT;
1761                         left -= len;
1762                         s += len;
1763                 }
1764         }
1765
1766         if (!write && !first && left) {
1767                 if(put_user('\n', s))
1768                         return -EFAULT;
1769                 left--, s++;
1770         }
1771         if (write) {
1772                 while (left) {
1773                         char c;
1774                         if (get_user(c, s++))
1775                                 return -EFAULT;
1776                         if (!isspace(c))
1777                                 break;
1778                         left--;
1779                 }
1780         }
1781         if (write && first)
1782                 return -EINVAL;
1783         *lenp -= left;
1784         *ppos += *lenp;
1785         return 0;
1786 #undef TMPBUFLEN
1787 }
1788
1789 /**
1790  * proc_dointvec - read a vector of integers
1791  * @table: the sysctl table
1792  * @write: %TRUE if this is a write to the sysctl file
1793  * @filp: the file structure
1794  * @buffer: the user buffer
1795  * @lenp: the size of the user buffer
1796  * @ppos: file position
1797  *
1798  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1799  * values from/to the user buffer, treated as an ASCII string.
1800  *
1801  * Returns 0 on success.
1802  */
1803 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1804                      void __user *buffer, size_t *lenp, loff_t *ppos)
1805 {
1806     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1807                             NULL,NULL);
1808 }
1809
1810 #define OP_SET  0
1811 #define OP_AND  1
1812 #define OP_OR   2
1813 #define OP_MAX  3
1814 #define OP_MIN  4
1815
1816 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1817                                       int *valp,
1818                                       int write, void *data)
1819 {
1820         int op = *(int *)data;
1821         if (write) {
1822                 int val = *negp ? -*lvalp : *lvalp;
1823                 switch(op) {
1824                 case OP_SET:    *valp = val; break;
1825                 case OP_AND:    *valp &= val; break;
1826                 case OP_OR:     *valp |= val; break;
1827                 case OP_MAX:    if(*valp < val)
1828                                         *valp = val;
1829                                 break;
1830                 case OP_MIN:    if(*valp > val)
1831                                 *valp = val;
1832                                 break;
1833                 }
1834         } else {
1835                 int val = *valp;
1836                 if (val < 0) {
1837                         *negp = -1;
1838                         *lvalp = (unsigned long)-val;
1839                 } else {
1840                         *negp = 0;
1841                         *lvalp = (unsigned long)val;
1842                 }
1843         }
1844         return 0;
1845 }
1846
1847 /*
1848  *      init may raise the set.
1849  */
1850
1851 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1852                         void __user *buffer, size_t *lenp, loff_t *ppos)
1853 {
1854         int op;
1855
1856         if (!capable(CAP_SYS_MODULE)) {
1857                 return -EPERM;
1858         }
1859
1860         op = (current->pid == 1) ? OP_SET : OP_AND;
1861         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1862                                 do_proc_dointvec_bset_conv,&op);
1863 }
1864
1865 struct do_proc_dointvec_minmax_conv_param {
1866         int *min;
1867         int *max;
1868 };
1869
1870 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1871                                         int *valp,
1872                                         int write, void *data)
1873 {
1874         struct do_proc_dointvec_minmax_conv_param *param = data;
1875         if (write) {
1876                 int val = *negp ? -*lvalp : *lvalp;
1877                 if ((param->min && *param->min > val) ||
1878                     (param->max && *param->max < val))
1879                         return -EINVAL;
1880                 *valp = val;
1881         } else {
1882                 int val = *valp;
1883                 if (val < 0) {
1884                         *negp = -1;
1885                         *lvalp = (unsigned long)-val;
1886                 } else {
1887                         *negp = 0;
1888                         *lvalp = (unsigned long)val;
1889                 }
1890         }
1891         return 0;
1892 }
1893
1894 /**
1895  * proc_dointvec_minmax - read a vector of integers with min/max values
1896  * @table: the sysctl table
1897  * @write: %TRUE if this is a write to the sysctl file
1898  * @filp: the file structure
1899  * @buffer: the user buffer
1900  * @lenp: the size of the user buffer
1901  * @ppos: file position
1902  *
1903  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1904  * values from/to the user buffer, treated as an ASCII string.
1905  *
1906  * This routine will ensure the values are within the range specified by
1907  * table->extra1 (min) and table->extra2 (max).
1908  *
1909  * Returns 0 on success.
1910  */
1911 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1912                   void __user *buffer, size_t *lenp, loff_t *ppos)
1913 {
1914         struct do_proc_dointvec_minmax_conv_param param = {
1915                 .min = (int *) table->extra1,
1916                 .max = (int *) table->extra2,
1917         };
1918         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1919                                 do_proc_dointvec_minmax_conv, &param);
1920 }
1921
1922 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1923                                      struct file *filp,
1924                                      void __user *buffer,
1925                                      size_t *lenp, loff_t *ppos,
1926                                      unsigned long convmul,
1927                                      unsigned long convdiv)
1928 {
1929 #define TMPBUFLEN 21
1930         unsigned long *i, *min, *max, val;
1931         int vleft, first=1, neg;
1932         size_t len, left;
1933         char buf[TMPBUFLEN], *p;
1934         char __user *s = buffer;
1935
1936         if (!table->data || !table->maxlen || !*lenp ||
1937             (*ppos && !write)) {
1938                 *lenp = 0;
1939                 return 0;
1940         }
1941
1942         i = (unsigned long *) table->data;
1943         min = (unsigned long *) table->extra1;
1944         max = (unsigned long *) table->extra2;
1945         vleft = table->maxlen / sizeof(unsigned long);
1946         left = *lenp;
1947
1948         for (; left && vleft--; i++, min++, max++, first=0) {
1949                 if (write) {
1950                         while (left) {
1951                                 char c;
1952                                 if (get_user(c, s))
1953                                         return -EFAULT;
1954                                 if (!isspace(c))
1955                                         break;
1956                                 left--;
1957                                 s++;
1958                         }
1959                         if (!left)
1960                                 break;
1961                         neg = 0;
1962                         len = left;
1963                         if (len > TMPBUFLEN-1)
1964                                 len = TMPBUFLEN-1;
1965                         if (copy_from_user(buf, s, len))
1966                                 return -EFAULT;
1967                         buf[len] = 0;
1968                         p = buf;
1969                         if (*p == '-' && left > 1) {
1970                                 neg = 1;
1971                                 left--, p++;
1972                         }
1973                         if (*p < '0' || *p > '9')
1974                                 break;
1975                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1976                         len = p-buf;
1977                         if ((len < left) && *p && !isspace(*p))
1978                                 break;
1979                         if (neg)
1980                                 val = -val;
1981                         s += len;
1982                         left -= len;
1983
1984                         if(neg)
1985                                 continue;
1986                         if ((min && val < *min) || (max && val > *max))
1987                                 continue;
1988                         *i = val;
1989                 } else {
1990                         p = buf;
1991                         if (!first)
1992                                 *p++ = '\t';
1993                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1994                         len = strlen(buf);
1995                         if (len > left)
1996                                 len = left;
1997                         if(copy_to_user(s, buf, len))
1998                                 return -EFAULT;
1999                         left -= len;
2000                         s += len;
2001                 }
2002         }
2003
2004         if (!write && !first && left) {
2005                 if(put_user('\n', s))
2006                         return -EFAULT;
2007                 left--, s++;
2008         }
2009         if (write) {
2010                 while (left) {
2011                         char c;
2012                         if (get_user(c, s++))
2013                                 return -EFAULT;
2014                         if (!isspace(c))
2015                                 break;
2016                         left--;
2017                 }
2018         }
2019         if (write && first)
2020                 return -EINVAL;
2021         *lenp -= left;
2022         *ppos += *lenp;
2023         return 0;
2024 #undef TMPBUFLEN
2025 }
2026
2027 /**
2028  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2029  * @table: the sysctl table
2030  * @write: %TRUE if this is a write to the sysctl file
2031  * @filp: the file structure
2032  * @buffer: the user buffer
2033  * @lenp: the size of the user buffer
2034  * @ppos: file position
2035  *
2036  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2037  * values from/to the user buffer, treated as an ASCII string.
2038  *
2039  * This routine will ensure the values are within the range specified by
2040  * table->extra1 (min) and table->extra2 (max).
2041  *
2042  * Returns 0 on success.
2043  */
2044 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2045                            void __user *buffer, size_t *lenp, loff_t *ppos)
2046 {
2047     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2048 }
2049
2050 /**
2051  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2052  * @table: the sysctl table
2053  * @write: %TRUE if this is a write to the sysctl file
2054  * @filp: the file structure
2055  * @buffer: the user buffer
2056  * @lenp: the size of the user buffer
2057  * @ppos: file position
2058  *
2059  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2060  * values from/to the user buffer, treated as an ASCII string. The values
2061  * are treated as milliseconds, and converted to jiffies when they are stored.
2062  *
2063  * This routine will ensure the values are within the range specified by
2064  * table->extra1 (min) and table->extra2 (max).
2065  *
2066  * Returns 0 on success.
2067  */
2068 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2069                                       struct file *filp,
2070                                       void __user *buffer,
2071                                       size_t *lenp, loff_t *ppos)
2072 {
2073     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2074                                      lenp, ppos, HZ, 1000l);
2075 }
2076
2077
2078 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2079                                          int *valp,
2080                                          int write, void *data)
2081 {
2082         if (write) {
2083                 if (*lvalp > LONG_MAX / HZ)
2084                         return 1;
2085                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2086         } else {
2087                 int val = *valp;
2088                 unsigned long lval;
2089                 if (val < 0) {
2090                         *negp = -1;
2091                         lval = (unsigned long)-val;
2092                 } else {
2093                         *negp = 0;
2094                         lval = (unsigned long)val;
2095                 }
2096                 *lvalp = lval / HZ;
2097         }
2098         return 0;
2099 }
2100
2101 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2102                                                 int *valp,
2103                                                 int write, void *data)
2104 {
2105         if (write) {
2106                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2107                         return 1;
2108                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2109         } else {
2110                 int val = *valp;
2111                 unsigned long lval;
2112                 if (val < 0) {
2113                         *negp = -1;
2114                         lval = (unsigned long)-val;
2115                 } else {
2116                         *negp = 0;
2117                         lval = (unsigned long)val;
2118                 }
2119                 *lvalp = jiffies_to_clock_t(lval);
2120         }
2121         return 0;
2122 }
2123
2124 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2125                                             int *valp,
2126                                             int write, void *data)
2127 {
2128         if (write) {
2129                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2130         } else {
2131                 int val = *valp;
2132                 unsigned long lval;
2133                 if (val < 0) {
2134                         *negp = -1;
2135                         lval = (unsigned long)-val;
2136                 } else {
2137                         *negp = 0;
2138                         lval = (unsigned long)val;
2139                 }
2140                 *lvalp = jiffies_to_msecs(lval);
2141         }
2142         return 0;
2143 }
2144
2145 /**
2146  * proc_dointvec_jiffies - read a vector of integers as seconds
2147  * @table: the sysctl table
2148  * @write: %TRUE if this is a write to the sysctl file
2149  * @filp: the file structure
2150  * @buffer: the user buffer
2151  * @lenp: the size of the user buffer
2152  * @ppos: file position
2153  *
2154  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2155  * values from/to the user buffer, treated as an ASCII string.
2156  * The values read are assumed to be in seconds, and are converted into
2157  * jiffies.
2158  *
2159  * Returns 0 on success.
2160  */
2161 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2162                           void __user *buffer, size_t *lenp, loff_t *ppos)
2163 {
2164     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2165                             do_proc_dointvec_jiffies_conv,NULL);
2166 }
2167
2168 /**
2169  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2170  * @table: the sysctl table
2171  * @write: %TRUE if this is a write to the sysctl file
2172  * @filp: the file structure
2173  * @buffer: the user buffer
2174  * @lenp: the size of the user buffer
2175  * @ppos: pointer to the file position
2176  *
2177  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2178  * values from/to the user buffer, treated as an ASCII string.
2179  * The values read are assumed to be in 1/USER_HZ seconds, and
2180  * are converted into jiffies.
2181  *
2182  * Returns 0 on success.
2183  */
2184 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2185                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2186 {
2187     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2188                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2189 }
2190
2191 /**
2192  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2193  * @table: the sysctl table
2194  * @write: %TRUE if this is a write to the sysctl file
2195  * @filp: the file structure
2196  * @buffer: the user buffer
2197  * @lenp: the size of the user buffer
2198  * @ppos: file position
2199  * @ppos: the current position in the file
2200  *
2201  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2202  * values from/to the user buffer, treated as an ASCII string.
2203  * The values read are assumed to be in 1/1000 seconds, and
2204  * are converted into jiffies.
2205  *
2206  * Returns 0 on success.
2207  */
2208 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2209                              void __user *buffer, size_t *lenp, loff_t *ppos)
2210 {
2211         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2212                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2213 }
2214
2215 #else /* CONFIG_PROC_FS */
2216
2217 int proc_dostring(ctl_table *table, int write, struct file *filp,
2218                   void __user *buffer, size_t *lenp, loff_t *ppos)
2219 {
2220         return -ENOSYS;
2221 }
2222
2223 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2224                             void __user *buffer, size_t *lenp, loff_t *ppos)
2225 {
2226         return -ENOSYS;
2227 }
2228
2229 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2230                   void __user *buffer, size_t *lenp, loff_t *ppos)
2231 {
2232         return -ENOSYS;
2233 }
2234
2235 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2236                         void __user *buffer, size_t *lenp, loff_t *ppos)
2237 {
2238         return -ENOSYS;
2239 }
2240
2241 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2242                     void __user *buffer, size_t *lenp, loff_t *ppos)
2243 {
2244         return -ENOSYS;
2245 }
2246
2247 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2248                     void __user *buffer, size_t *lenp, loff_t *ppos)
2249 {
2250         return -ENOSYS;
2251 }
2252
2253 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2254                     void __user *buffer, size_t *lenp, loff_t *ppos)
2255 {
2256         return -ENOSYS;
2257 }
2258
2259 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2260                              void __user *buffer, size_t *lenp, loff_t *ppos)
2261 {
2262         return -ENOSYS;
2263 }
2264
2265 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2266                     void __user *buffer, size_t *lenp, loff_t *ppos)
2267 {
2268         return -ENOSYS;
2269 }
2270
2271 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2272                                       struct file *filp,
2273                                       void __user *buffer,
2274                                       size_t *lenp, loff_t *ppos)
2275 {
2276     return -ENOSYS;
2277 }
2278
2279
2280 #endif /* CONFIG_PROC_FS */
2281
2282
2283 /*
2284  * General sysctl support routines
2285  */
2286
2287 /* The generic string strategy routine: */
2288 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2289                   void __user *oldval, size_t __user *oldlenp,
2290                   void __user *newval, size_t newlen, void **context)
2291 {
2292         if (!table->data || !table->maxlen)
2293                 return -ENOTDIR;
2294
2295         if (oldval && oldlenp) {
2296                 size_t bufsize;
2297                 if (get_user(bufsize, oldlenp))
2298                         return -EFAULT;
2299                 if (bufsize) {
2300                         size_t len = strlen(table->data), copied;
2301
2302                         /* This shouldn't trigger for a well-formed sysctl */
2303                         if (len > table->maxlen)
2304                                 len = table->maxlen;
2305
2306                         /* Copy up to a max of bufsize-1 bytes of the string */
2307                         copied = (len >= bufsize) ? bufsize - 1 : len;
2308
2309                         if (copy_to_user(oldval, table->data, copied) ||
2310                             put_user(0, (char __user *)(oldval + copied)))
2311                                 return -EFAULT;
2312                         if (put_user(len, oldlenp))
2313                                 return -EFAULT;
2314                 }
2315         }
2316         if (newval && newlen) {
2317                 size_t len = newlen;
2318                 if (len > table->maxlen)
2319                         len = table->maxlen;
2320                 if(copy_from_user(table->data, newval, len))
2321                         return -EFAULT;
2322                 if (len == table->maxlen)
2323                         len--;
2324                 ((char *) table->data)[len] = 0;
2325         }
2326         return 1;
2327 }
2328
2329 /*
2330  * This function makes sure that all of the integers in the vector
2331  * are between the minimum and maximum values given in the arrays
2332  * table->extra1 and table->extra2, respectively.
2333  */
2334 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2335                 void __user *oldval, size_t __user *oldlenp,
2336                 void __user *newval, size_t newlen, void **context)
2337 {
2338
2339         if (newval && newlen) {
2340                 int __user *vec = (int __user *) newval;
2341                 int *min = (int *) table->extra1;
2342                 int *max = (int *) table->extra2;
2343                 size_t length;
2344                 int i;
2345
2346                 if (newlen % sizeof(int) != 0)
2347                         return -EINVAL;
2348
2349                 if (!table->extra1 && !table->extra2)
2350                         return 0;
2351
2352                 if (newlen > table->maxlen)
2353                         newlen = table->maxlen;
2354                 length = newlen / sizeof(int);
2355
2356                 for (i = 0; i < length; i++) {
2357                         int value;
2358                         if (get_user(value, vec + i))
2359                                 return -EFAULT;
2360                         if (min && value < min[i])
2361                                 return -EINVAL;
2362                         if (max && value > max[i])
2363                                 return -EINVAL;
2364                 }
2365         }
2366         return 0;
2367 }
2368
2369 /* Strategy function to convert jiffies to seconds */
2370 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2371                 void __user *oldval, size_t __user *oldlenp,
2372                 void __user *newval, size_t newlen, void **context)
2373 {
2374         if (oldval) {
2375                 size_t olen;
2376                 if (oldlenp) {
2377                         if (get_user(olen, oldlenp))
2378                                 return -EFAULT;
2379                         if (olen!=sizeof(int))
2380                                 return -EINVAL;
2381                 }
2382                 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2383                     (oldlenp && put_user(sizeof(int),oldlenp)))
2384                         return -EFAULT;
2385         }
2386         if (newval && newlen) {
2387                 int new;
2388                 if (newlen != sizeof(int))
2389                         return -EINVAL;
2390                 if (get_user(new, (int __user *)newval))
2391                         return -EFAULT;
2392                 *(int *)(table->data) = new*HZ;
2393         }
2394         return 1;
2395 }
2396
2397 /* Strategy function to convert jiffies to seconds */
2398 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2399                 void __user *oldval, size_t __user *oldlenp,
2400                 void __user *newval, size_t newlen, void **context)
2401 {
2402         if (oldval) {
2403                 size_t olen;
2404                 if (oldlenp) {
2405                         if (get_user(olen, oldlenp))
2406                                 return -EFAULT;
2407                         if (olen!=sizeof(int))
2408                                 return -EINVAL;
2409                 }
2410                 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2411                     (oldlenp && put_user(sizeof(int),oldlenp)))
2412                         return -EFAULT;
2413         }
2414         if (newval && newlen) {
2415                 int new;
2416                 if (newlen != sizeof(int))
2417                         return -EINVAL;
2418                 if (get_user(new, (int __user *)newval))
2419                         return -EFAULT;
2420                 *(int *)(table->data) = msecs_to_jiffies(new);
2421         }
2422         return 1;
2423 }
2424
2425 #else /* CONFIG_SYSCTL */
2426
2427
2428 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2429 {
2430         return -ENOSYS;
2431 }
2432
2433 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2434                   void __user *oldval, size_t __user *oldlenp,
2435                   void __user *newval, size_t newlen, void **context)
2436 {
2437         return -ENOSYS;
2438 }
2439
2440 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2441                 void __user *oldval, size_t __user *oldlenp,
2442                 void __user *newval, size_t newlen, void **context)
2443 {
2444         return -ENOSYS;
2445 }
2446
2447 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2448                 void __user *oldval, size_t __user *oldlenp,
2449                 void __user *newval, size_t newlen, void **context)
2450 {
2451         return -ENOSYS;
2452 }
2453
2454 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2455                 void __user *oldval, size_t __user *oldlenp,
2456                 void __user *newval, size_t newlen, void **context)
2457 {
2458         return -ENOSYS;
2459 }
2460
2461 int proc_dostring(ctl_table *table, int write, struct file *filp,
2462                   void __user *buffer, size_t *lenp, loff_t *ppos)
2463 {
2464         return -ENOSYS;
2465 }
2466
2467 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2468                   void __user *buffer, size_t *lenp, loff_t *ppos)
2469 {
2470         return -ENOSYS;
2471 }
2472
2473 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2474                         void __user *buffer, size_t *lenp, loff_t *ppos)
2475 {
2476         return -ENOSYS;
2477 }
2478
2479 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2480                     void __user *buffer, size_t *lenp, loff_t *ppos)
2481 {
2482         return -ENOSYS;
2483 }
2484
2485 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2486                           void __user *buffer, size_t *lenp, loff_t *ppos)
2487 {
2488         return -ENOSYS;
2489 }
2490
2491 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2492                           void __user *buffer, size_t *lenp, loff_t *ppos)
2493 {
2494         return -ENOSYS;
2495 }
2496
2497 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2498                              void __user *buffer, size_t *lenp, loff_t *ppos)
2499 {
2500         return -ENOSYS;
2501 }
2502
2503 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2504                     void __user *buffer, size_t *lenp, loff_t *ppos)
2505 {
2506         return -ENOSYS;
2507 }
2508
2509 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2510                                       struct file *filp,
2511                                       void __user *buffer,
2512                                       size_t *lenp, loff_t *ppos)
2513 {
2514     return -ENOSYS;
2515 }
2516
2517 struct ctl_table_header * register_sysctl_table(ctl_table * table,
2518                                                 int insert_at_head)
2519 {
2520         return NULL;
2521 }
2522
2523 void unregister_sysctl_table(struct ctl_table_header * table)
2524 {
2525 }
2526
2527 #endif /* CONFIG_SYSCTL */
2528
2529 /*
2530  * No sense putting this after each symbol definition, twice,
2531  * exception granted :-)
2532  */
2533 EXPORT_SYMBOL(proc_dointvec);
2534 EXPORT_SYMBOL(proc_dointvec_jiffies);
2535 EXPORT_SYMBOL(proc_dointvec_minmax);
2536 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2537 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2538 EXPORT_SYMBOL(proc_dostring);
2539 EXPORT_SYMBOL(proc_doulongvec_minmax);
2540 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2541 EXPORT_SYMBOL(register_sysctl_table);
2542 EXPORT_SYMBOL(sysctl_intvec);
2543 EXPORT_SYMBOL(sysctl_jiffies);
2544 EXPORT_SYMBOL(sysctl_ms_jiffies);
2545 EXPORT_SYMBOL(sysctl_string);
2546 EXPORT_SYMBOL(unregister_sysctl_table);