SAFE public projects git trees. - safe/jmp/linux-2.6/blob - kernel/sysctl.c

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