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   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 int nmi_watchdog_enabled;
  80 extern int proc_nmi_enabled(struct ctl_table *, int , struct file *,
  81                         void __user *, size_t *, loff_t *);
  82 #endif
  83
  84 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  85 static int maxolduid = 65535;
  86 static int minolduid;
  87 static int min_percpu_pagelist_fract = 8;
  88
  89 static int ngroups_max = NGROUPS_MAX;
  90
  91 #ifdef CONFIG_KMOD
  92 extern char modprobe_path[];
  93 #endif
  94 #ifdef CONFIG_CHR_DEV_SG
  95 extern int sg_big_buff;
  96 #endif
  97 #ifdef CONFIG_SYSVIPC
  98 extern size_t shm_ctlmax;
  99 extern size_t shm_ctlall;
 100 extern int shm_ctlmni;
 101 extern int msg_ctlmax;
 102 extern int msg_ctlmnb;
 103 extern int msg_ctlmni;
 104 extern int sem_ctls[];
 105 #endif
 106
 107 #ifdef __sparc__
 108 extern char reboot_command [];
 109 extern int stop_a_enabled;
 110 extern int scons_pwroff;
 111 #endif
 112
 113 #ifdef __hppa__
 114 extern int pwrsw_enabled;
 115 extern int unaligned_enabled;
 116 #endif
 117
 118 #ifdef CONFIG_S390
 119 #ifdef CONFIG_MATHEMU
 120 extern int sysctl_ieee_emulation_warnings;
 121 #endif
 122 extern int sysctl_userprocess_debug;
 123 extern int spin_retry;
 124 #endif
 125
 126 extern int sysctl_hz_timer;
 127
 128 #ifdef CONFIG_BSD_PROCESS_ACCT
 129 extern int acct_parm[];
 130 #endif
 131
 132 #ifdef CONFIG_IA64
 133 extern int no_unaligned_warning;
 134 #endif
 135
 136 #ifdef CONFIG_RT_MUTEXES
 137 extern int max_lock_depth;
 138 #endif
 139
 140 static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
 141                        ctl_table *, void **);
 142 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
 143                   void __user *buffer, size_t *lenp, loff_t *ppos);
 144
 145 static ctl_table root_table[];
 146 static struct ctl_table_header root_table_header =
 147         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 148
 149 static ctl_table kern_table[];
 150 static ctl_table vm_table[];
 151 static ctl_table fs_table[];
 152 static ctl_table debug_table[];
 153 static ctl_table dev_table[];
 154 extern ctl_table random_table[];
 155 #ifdef CONFIG_UNIX98_PTYS
 156 extern ctl_table pty_table[];
 157 #endif
 158 #ifdef CONFIG_INOTIFY_USER
 159 extern ctl_table inotify_table[];
 160 #endif
 161
 162 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 163 int sysctl_legacy_va_layout;
 164 #endif
 165
 166 /* /proc declarations: */
 167
 168 #ifdef CONFIG_PROC_FS
 169
 170 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
 171 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
 172 static int proc_opensys(struct inode *, struct file *);
 173
 174 struct file_operations proc_sys_file_operations = {
 175         .open           = proc_opensys,
 176         .read           = proc_readsys,
 177         .write          = proc_writesys,
 178 };
 179
 180 extern struct proc_dir_entry *proc_sys_root;
 181
 182 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
 183 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
 184 #endif
 185
 186 /* The default sysctl tables: */
 187
 188 static ctl_table root_table[] = {
 189         {
 190                 .ctl_name       = CTL_KERN,
 191                 .procname       = "kernel",
 192                 .mode           = 0555,
 193                 .child          = kern_table,
 194         },
 195         {
 196                 .ctl_name       = CTL_VM,
 197                 .procname       = "vm",
 198                 .mode           = 0555,
 199                 .child          = vm_table,
 200         },
 201 #ifdef CONFIG_NET
 202         {
 203                 .ctl_name       = CTL_NET,
 204                 .procname       = "net",
 205                 .mode           = 0555,
 206                 .child          = net_table,
 207         },
 208 #endif
 209         {
 210                 .ctl_name       = CTL_FS,
 211                 .procname       = "fs",
 212                 .mode           = 0555,
 213                 .child          = fs_table,
 214         },
 215         {
 216                 .ctl_name       = CTL_DEBUG,
 217                 .procname       = "debug",
 218                 .mode           = 0555,
 219                 .child          = debug_table,
 220         },
 221         {
 222                 .ctl_name       = CTL_DEV,
 223                 .procname       = "dev",
 224                 .mode           = 0555,
 225                 .child          = dev_table,
 226         },
 227
 228         { .ctl_name = 0 }
 229 };
 230
 231 static ctl_table kern_table[] = {
 232         {
 233                 .ctl_name       = KERN_OSTYPE,
 234                 .procname       = "ostype",
 235                 .data           = system_utsname.sysname,
 236                 .maxlen         = sizeof(system_utsname.sysname),
 237                 .mode           = 0444,
 238                 .proc_handler   = &proc_doutsstring,
 239                 .strategy       = &sysctl_string,
 240         },
 241         {
 242                 .ctl_name       = KERN_OSRELEASE,
 243                 .procname       = "osrelease",
 244                 .data           = system_utsname.release,
 245                 .maxlen         = sizeof(system_utsname.release),
 246                 .mode           = 0444,
 247                 .proc_handler   = &proc_doutsstring,
 248                 .strategy       = &sysctl_string,
 249         },
 250         {
 251                 .ctl_name       = KERN_VERSION,
 252                 .procname       = "version",
 253                 .data           = system_utsname.version,
 254                 .maxlen         = sizeof(system_utsname.version),
 255                 .mode           = 0444,
 256                 .proc_handler   = &proc_doutsstring,
 257                 .strategy       = &sysctl_string,
 258         },
 259         {
 260                 .ctl_name       = KERN_NODENAME,
 261                 .procname       = "hostname",
 262                 .data           = system_utsname.nodename,
 263                 .maxlen         = sizeof(system_utsname.nodename),
 264                 .mode           = 0644,
 265                 .proc_handler   = &proc_doutsstring,
 266                 .strategy       = &sysctl_string,
 267         },
 268         {
 269                 .ctl_name       = KERN_DOMAINNAME,
 270                 .procname       = "domainname",
 271                 .data           = system_utsname.domainname,
 272                 .maxlen         = sizeof(system_utsname.domainname),
 273                 .mode           = 0644,
 274                 .proc_handler   = &proc_doutsstring,
 275                 .strategy       = &sysctl_string,
 276         },
 277         {
 278                 .ctl_name       = KERN_PANIC,
 279                 .procname       = "panic",
 280                 .data           = &panic_timeout,
 281                 .maxlen         = sizeof(int),
 282                 .mode           = 0644,
 283                 .proc_handler   = &proc_dointvec,
 284         },
 285         {
 286                 .ctl_name       = KERN_CORE_USES_PID,
 287                 .procname       = "core_uses_pid",
 288                 .data           = &core_uses_pid,
 289                 .maxlen         = sizeof(int),
 290                 .mode           = 0644,
 291                 .proc_handler   = &proc_dointvec,
 292         },
 293         {
 294                 .ctl_name       = KERN_CORE_PATTERN,
 295                 .procname       = "core_pattern",
 296                 .data           = core_pattern,
 297                 .maxlen         = 64,
 298                 .mode           = 0644,
 299                 .proc_handler   = &proc_dostring,
 300                 .strategy       = &sysctl_string,
 301         },
 302         {
 303                 .ctl_name       = KERN_TAINTED,
 304                 .procname       = "tainted",
 305                 .data           = &tainted,
 306                 .maxlen         = sizeof(int),
 307                 .mode           = 0444,
 308                 .proc_handler   = &proc_dointvec,
 309         },
 310         {
 311                 .ctl_name       = KERN_CAP_BSET,
 312                 .procname       = "cap-bound",
 313                 .data           = &cap_bset,
 314                 .maxlen         = sizeof(kernel_cap_t),
 315                 .mode           = 0600,
 316                 .proc_handler   = &proc_dointvec_bset,
 317         },
 318 #ifdef CONFIG_BLK_DEV_INITRD
 319         {
 320                 .ctl_name       = KERN_REALROOTDEV,
 321                 .procname       = "real-root-dev",
 322                 .data           = &real_root_dev,
 323                 .maxlen         = sizeof(int),
 324                 .mode           = 0644,
 325                 .proc_handler   = &proc_dointvec,
 326         },
 327 #endif
 328 #ifdef __sparc__
 329         {
 330                 .ctl_name       = KERN_SPARC_REBOOT,
 331                 .procname       = "reboot-cmd",
 332                 .data           = reboot_command,
 333                 .maxlen         = 256,
 334                 .mode           = 0644,
 335                 .proc_handler   = &proc_dostring,
 336                 .strategy       = &sysctl_string,
 337         },
 338         {
 339                 .ctl_name       = KERN_SPARC_STOP_A,
 340                 .procname       = "stop-a",
 341                 .data           = &stop_a_enabled,
 342                 .maxlen         = sizeof (int),
 343                 .mode           = 0644,
 344                 .proc_handler   = &proc_dointvec,
 345         },
 346         {
 347                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 348                 .procname       = "scons-poweroff",
 349                 .data           = &scons_pwroff,
 350                 .maxlen         = sizeof (int),
 351                 .mode           = 0644,
 352                 .proc_handler   = &proc_dointvec,
 353         },
 354 #endif
 355 #ifdef __hppa__
 356         {
 357                 .ctl_name       = KERN_HPPA_PWRSW,
 358                 .procname       = "soft-power",
 359                 .data           = &pwrsw_enabled,
 360                 .maxlen         = sizeof (int),
 361                 .mode           = 0644,
 362                 .proc_handler   = &proc_dointvec,
 363         },
 364         {
 365                 .ctl_name       = KERN_HPPA_UNALIGNED,
 366                 .procname       = "unaligned-trap",
 367                 .data           = &unaligned_enabled,
 368                 .maxlen         = sizeof (int),
 369                 .mode           = 0644,
 370                 .proc_handler   = &proc_dointvec,
 371         },
 372 #endif
 373         {
 374                 .ctl_name       = KERN_CTLALTDEL,
 375                 .procname       = "ctrl-alt-del",
 376                 .data           = &C_A_D,
 377                 .maxlen         = sizeof(int),
 378                 .mode           = 0644,
 379                 .proc_handler   = &proc_dointvec,
 380         },
 381         {
 382                 .ctl_name       = KERN_PRINTK,
 383                 .procname       = "printk",
 384                 .data           = &console_loglevel,
 385                 .maxlen         = 4*sizeof(int),
 386                 .mode           = 0644,
 387                 .proc_handler   = &proc_dointvec,
 388         },
 389 #ifdef CONFIG_KMOD
 390         {
 391                 .ctl_name       = KERN_MODPROBE,
 392                 .procname       = "modprobe",
 393                 .data           = &modprobe_path,
 394                 .maxlen         = KMOD_PATH_LEN,
 395                 .mode           = 0644,
 396                 .proc_handler   = &proc_dostring,
 397                 .strategy       = &sysctl_string,
 398         },
 399 #endif
 400 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 401         {
 402                 .ctl_name       = KERN_HOTPLUG,
 403                 .procname       = "hotplug",
 404                 .data           = &uevent_helper,
 405                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_dostring,
 408                 .strategy       = &sysctl_string,
 409         },
 410 #endif
 411 #ifdef CONFIG_CHR_DEV_SG
 412         {
 413                 .ctl_name       = KERN_SG_BIG_BUFF,
 414                 .procname       = "sg-big-buff",
 415                 .data           = &sg_big_buff,
 416                 .maxlen         = sizeof (int),
 417                 .mode           = 0444,
 418                 .proc_handler   = &proc_dointvec,
 419         },
 420 #endif
 421 #ifdef CONFIG_BSD_PROCESS_ACCT
 422         {
 423                 .ctl_name       = KERN_ACCT,
 424                 .procname       = "acct",
 425                 .data           = &acct_parm,
 426                 .maxlen         = 3*sizeof(int),
 427                 .mode           = 0644,
 428                 .proc_handler   = &proc_dointvec,
 429         },
 430 #endif
 431 #ifdef CONFIG_SYSVIPC
 432         {
 433                 .ctl_name       = KERN_SHMMAX,
 434                 .procname       = "shmmax",
 435                 .data           = &shm_ctlmax,
 436                 .maxlen         = sizeof (size_t),
 437                 .mode           = 0644,
 438                 .proc_handler   = &proc_doulongvec_minmax,
 439         },
 440         {
 441                 .ctl_name       = KERN_SHMALL,
 442                 .procname       = "shmall",
 443                 .data           = &shm_ctlall,
 444                 .maxlen         = sizeof (size_t),
 445                 .mode           = 0644,
 446                 .proc_handler   = &proc_doulongvec_minmax,
 447         },
 448         {
 449                 .ctl_name       = KERN_SHMMNI,
 450                 .procname       = "shmmni",
 451                 .data           = &shm_ctlmni,
 452                 .maxlen         = sizeof (int),
 453                 .mode           = 0644,
 454                 .proc_handler   = &proc_dointvec,
 455         },
 456         {
 457                 .ctl_name       = KERN_MSGMAX,
 458                 .procname       = "msgmax",
 459                 .data           = &msg_ctlmax,
 460                 .maxlen         = sizeof (int),
 461                 .mode           = 0644,
 462                 .proc_handler   = &proc_dointvec,
 463         },
 464         {
 465                 .ctl_name       = KERN_MSGMNI,
 466                 .procname       = "msgmni",
 467                 .data           = &msg_ctlmni,
 468                 .maxlen         = sizeof (int),
 469                 .mode           = 0644,
 470                 .proc_handler   = &proc_dointvec,
 471         },
 472         {
 473                 .ctl_name       = KERN_MSGMNB,
 474                 .procname       =  "msgmnb",
 475                 .data           = &msg_ctlmnb,
 476                 .maxlen         = sizeof (int),
 477                 .mode           = 0644,
 478                 .proc_handler   = &proc_dointvec,
 479         },
 480         {
 481                 .ctl_name       = KERN_SEM,
 482                 .procname       = "sem",
 483                 .data           = &sem_ctls,
 484                 .maxlen         = 4*sizeof (int),
 485                 .mode           = 0644,
 486                 .proc_handler   = &proc_dointvec,
 487         },
 488 #endif
 489 #ifdef CONFIG_MAGIC_SYSRQ
 490         {
 491                 .ctl_name       = KERN_SYSRQ,
 492                 .procname       = "sysrq",
 493                 .data           = &sysrq_enabled,
 494                 .maxlen         = sizeof (int),
 495                 .mode           = 0644,
 496                 .proc_handler   = &proc_dointvec,
 497         },
 498 #endif
 499         {
 500                 .ctl_name       = KERN_CADPID,
 501                 .procname       = "cad_pid",
 502                 .data           = &cad_pid,
 503                 .maxlen         = sizeof (int),
 504                 .mode           = 0600,
 505                 .proc_handler   = &proc_dointvec,
 506         },
 507         {
 508                 .ctl_name       = KERN_MAX_THREADS,
 509                 .procname       = "threads-max",
 510                 .data           = &max_threads,
 511                 .maxlen         = sizeof(int),
 512                 .mode           = 0644,
 513                 .proc_handler   = &proc_dointvec,
 514         },
 515         {
 516                 .ctl_name       = KERN_RANDOM,
 517                 .procname       = "random",
 518                 .mode           = 0555,
 519                 .child          = random_table,
 520         },
 521 #ifdef CONFIG_UNIX98_PTYS
 522         {
 523                 .ctl_name       = KERN_PTY,
 524                 .procname       = "pty",
 525                 .mode           = 0555,
 526                 .child          = pty_table,
 527         },
 528 #endif
 529         {
 530                 .ctl_name       = KERN_OVERFLOWUID,
 531                 .procname       = "overflowuid",
 532                 .data           = &overflowuid,
 533                 .maxlen         = sizeof(int),
 534                 .mode           = 0644,
 535                 .proc_handler   = &proc_dointvec_minmax,
 536                 .strategy       = &sysctl_intvec,
 537                 .extra1         = &minolduid,
 538                 .extra2         = &maxolduid,
 539         },
 540         {
 541                 .ctl_name       = KERN_OVERFLOWGID,
 542                 .procname       = "overflowgid",
 543                 .data           = &overflowgid,
 544                 .maxlen         = sizeof(int),
 545                 .mode           = 0644,
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .strategy       = &sysctl_intvec,
 548                 .extra1         = &minolduid,
 549                 .extra2         = &maxolduid,
 550         },
 551 #ifdef CONFIG_S390
 552 #ifdef CONFIG_MATHEMU
 553         {
 554                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 555                 .procname       = "ieee_emulation_warnings",
 556                 .data           = &sysctl_ieee_emulation_warnings,
 557                 .maxlen         = sizeof(int),
 558                 .mode           = 0644,
 559                 .proc_handler   = &proc_dointvec,
 560         },
 561 #endif
 562 #ifdef CONFIG_NO_IDLE_HZ
 563         {
 564                 .ctl_name       = KERN_HZ_TIMER,
 565                 .procname       = "hz_timer",
 566                 .data           = &sysctl_hz_timer,
 567                 .maxlen         = sizeof(int),
 568                 .mode           = 0644,
 569                 .proc_handler   = &proc_dointvec,
 570         },
 571 #endif
 572         {
 573                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 574                 .procname       = "userprocess_debug",
 575                 .data           = &sysctl_userprocess_debug,
 576                 .maxlen         = sizeof(int),
 577                 .mode           = 0644,
 578                 .proc_handler   = &proc_dointvec,
 579         },
 580 #endif
 581         {
 582                 .ctl_name       = KERN_PIDMAX,
 583                 .procname       = "pid_max",
 584                 .data           = &pid_max,
 585                 .maxlen         = sizeof (int),
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dointvec_minmax,
 588                 .strategy       = sysctl_intvec,
 589                 .extra1         = &pid_max_min,
 590                 .extra2         = &pid_max_max,
 591         },
 592         {
 593                 .ctl_name       = KERN_PANIC_ON_OOPS,
 594                 .procname       = "panic_on_oops",
 595                 .data           = &panic_on_oops,
 596                 .maxlen         = sizeof(int),
 597                 .mode           = 0644,
 598                 .proc_handler   = &proc_dointvec,
 599         },
 600         {
 601                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 602                 .procname       = "printk_ratelimit",
 603                 .data           = &printk_ratelimit_jiffies,
 604                 .maxlen         = sizeof(int),
 605                 .mode           = 0644,
 606                 .proc_handler   = &proc_dointvec_jiffies,
 607                 .strategy       = &sysctl_jiffies,
 608         },
 609         {
 610                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 611                 .procname       = "printk_ratelimit_burst",
 612                 .data           = &printk_ratelimit_burst,
 613                 .maxlen         = sizeof(int),
 614                 .mode           = 0644,
 615                 .proc_handler   = &proc_dointvec,
 616         },
 617         {
 618                 .ctl_name       = KERN_NGROUPS_MAX,
 619                 .procname       = "ngroups_max",
 620                 .data           = &ngroups_max,
 621                 .maxlen         = sizeof (int),
 622                 .mode           = 0444,
 623                 .proc_handler   = &proc_dointvec,
 624         },
 625 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 626         {
 627                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 628                 .procname       = "unknown_nmi_panic",
 629                 .data           = &unknown_nmi_panic,
 630                 .maxlen         = sizeof (int),
 631                 .mode           = 0644,
 632                 .proc_handler   = &proc_dointvec,
 633         },
 634         {
 635                 .ctl_name       = KERN_NMI_WATCHDOG,
 636                 .procname       = "nmi_watchdog",
 637                 .data           = &nmi_watchdog_enabled,
 638                 .maxlen         = sizeof (int),
 639                 .mode           = 0644,
 640                 .proc_handler   = &proc_nmi_enabled,
 641         },
 642 #endif
 643 #if defined(CONFIG_X86)
 644         {
 645                 .ctl_name       = KERN_PANIC_ON_NMI,
 646                 .procname       = "panic_on_unrecovered_nmi",
 647                 .data           = &panic_on_unrecovered_nmi,
 648                 .maxlen         = sizeof(int),
 649                 .mode           = 0644,
 650                 .proc_handler   = &proc_dointvec,
 651         },
 652         {
 653                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 654                 .procname       = "bootloader_type",
 655                 .data           = &bootloader_type,
 656                 .maxlen         = sizeof (int),
 657                 .mode           = 0444,
 658                 .proc_handler   = &proc_dointvec,
 659         },
 660 #endif
 661 #if defined(CONFIG_MMU)
 662         {
 663                 .ctl_name       = KERN_RANDOMIZE,
 664                 .procname       = "randomize_va_space",
 665                 .data           = &randomize_va_space,
 666                 .maxlen         = sizeof(int),
 667                 .mode           = 0644,
 668                 .proc_handler   = &proc_dointvec,
 669         },
 670 #endif
 671 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 672         {
 673                 .ctl_name       = KERN_SPIN_RETRY,
 674                 .procname       = "spin_retry",
 675                 .data           = &spin_retry,
 676                 .maxlen         = sizeof (int),
 677                 .mode           = 0644,
 678                 .proc_handler   = &proc_dointvec,
 679         },
 680 #endif
 681 #ifdef CONFIG_ACPI_SLEEP
 682         {
 683                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 684                 .procname       = "acpi_video_flags",
 685                 .data           = &acpi_video_flags,
 686                 .maxlen         = sizeof (unsigned long),
 687                 .mode           = 0644,
 688                 .proc_handler   = &proc_doulongvec_minmax,
 689         },
 690 #endif
 691 #ifdef CONFIG_IA64
 692         {
 693                 .ctl_name       = KERN_IA64_UNALIGNED,
 694                 .procname       = "ignore-unaligned-usertrap",
 695                 .data           = &no_unaligned_warning,
 696                 .maxlen         = sizeof (int),
 697                 .mode           = 0644,
 698                 .proc_handler   = &proc_dointvec,
 699         },
 700 #endif
 701 #ifdef CONFIG_COMPAT
 702         {
 703                 .ctl_name       = KERN_COMPAT_LOG,
 704                 .procname       = "compat-log",
 705                 .data           = &compat_log,
 706                 .maxlen         = sizeof (int),
 707                 .mode           = 0644,
 708                 .proc_handler   = &proc_dointvec,
 709         },
 710 #endif
 711 #ifdef CONFIG_RT_MUTEXES
 712         {
 713                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 714                 .procname       = "max_lock_depth",
 715                 .data           = &max_lock_depth,
 716                 .maxlen         = sizeof(int),
 717                 .mode           = 0644,
 718                 .proc_handler   = &proc_dointvec,
 719         },
 720 #endif
 721
 722         { .ctl_name = 0 }
 723 };
 724
 725 /* Constants for minimum and maximum testing in vm_table.
 726    We use these as one-element integer vectors. */
 727 static int zero;
 728 static int one_hundred = 100;
 729
 730
 731 static ctl_table vm_table[] = {
 732         {
 733                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 734                 .procname       = "overcommit_memory",
 735                 .data           = &sysctl_overcommit_memory,
 736                 .maxlen         = sizeof(sysctl_overcommit_memory),
 737                 .mode           = 0644,
 738                 .proc_handler   = &proc_dointvec,
 739         },
 740         {
 741                 .ctl_name       = VM_PANIC_ON_OOM,
 742                 .procname       = "panic_on_oom",
 743                 .data           = &sysctl_panic_on_oom,
 744                 .maxlen         = sizeof(sysctl_panic_on_oom),
 745                 .mode           = 0644,
 746                 .proc_handler   = &proc_dointvec,
 747         },
 748         {
 749                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 750                 .procname       = "overcommit_ratio",
 751                 .data           = &sysctl_overcommit_ratio,
 752                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 753                 .mode           = 0644,
 754                 .proc_handler   = &proc_dointvec,
 755         },
 756         {
 757                 .ctl_name       = VM_PAGE_CLUSTER,
 758                 .procname       = "page-cluster",
 759                 .data           = &page_cluster,
 760                 .maxlen         = sizeof(int),
 761                 .mode           = 0644,
 762                 .proc_handler   = &proc_dointvec,
 763         },
 764         {
 765                 .ctl_name       = VM_DIRTY_BACKGROUND,
 766                 .procname       = "dirty_background_ratio",
 767                 .data           = &dirty_background_ratio,
 768                 .maxlen         = sizeof(dirty_background_ratio),
 769                 .mode           = 0644,
 770                 .proc_handler   = &proc_dointvec_minmax,
 771                 .strategy       = &sysctl_intvec,
 772                 .extra1         = &zero,
 773                 .extra2         = &one_hundred,
 774         },
 775         {
 776                 .ctl_name       = VM_DIRTY_RATIO,
 777                 .procname       = "dirty_ratio",
 778                 .data           = &vm_dirty_ratio,
 779                 .maxlen         = sizeof(vm_dirty_ratio),
 780                 .mode           = 0644,
 781                 .proc_handler   = &proc_dointvec_minmax,
 782                 .strategy       = &sysctl_intvec,
 783                 .extra1         = &zero,
 784                 .extra2         = &one_hundred,
 785         },
 786         {
 787                 .ctl_name       = VM_DIRTY_WB_CS,
 788                 .procname       = "dirty_writeback_centisecs",
 789                 .data           = &dirty_writeback_interval,
 790                 .maxlen         = sizeof(dirty_writeback_interval),
 791                 .mode           = 0644,
 792                 .proc_handler   = &dirty_writeback_centisecs_handler,
 793         },
 794         {
 795                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 796                 .procname       = "dirty_expire_centisecs",
 797                 .data           = &dirty_expire_interval,
 798                 .maxlen         = sizeof(dirty_expire_interval),
 799                 .mode           = 0644,
 800                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 801         },
 802         {
 803                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 804                 .procname       = "nr_pdflush_threads",
 805                 .data           = &nr_pdflush_threads,
 806                 .maxlen         = sizeof nr_pdflush_threads,
 807                 .mode           = 0444 /* read-only*/,
 808                 .proc_handler   = &proc_dointvec,
 809         },
 810         {
 811                 .ctl_name       = VM_SWAPPINESS,
 812                 .procname       = "swappiness",
 813                 .data           = &vm_swappiness,
 814                 .maxlen         = sizeof(vm_swappiness),
 815                 .mode           = 0644,
 816                 .proc_handler   = &proc_dointvec_minmax,
 817                 .strategy       = &sysctl_intvec,
 818                 .extra1         = &zero,
 819                 .extra2         = &one_hundred,
 820         },
 821 #ifdef CONFIG_HUGETLB_PAGE
 822          {
 823                 .ctl_name       = VM_HUGETLB_PAGES,
 824                 .procname       = "nr_hugepages",
 825                 .data           = &max_huge_pages,
 826                 .maxlen         = sizeof(unsigned long),
 827                 .mode           = 0644,
 828                 .proc_handler   = &hugetlb_sysctl_handler,
 829                 .extra1         = (void *)&hugetlb_zero,
 830                 .extra2         = (void *)&hugetlb_infinity,
 831          },
 832          {
 833                 .ctl_name       = VM_HUGETLB_GROUP,
 834                 .procname       = "hugetlb_shm_group",
 835                 .data           = &sysctl_hugetlb_shm_group,
 836                 .maxlen         = sizeof(gid_t),
 837                 .mode           = 0644,
 838                 .proc_handler   = &proc_dointvec,
 839          },
 840 #endif
 841         {
 842                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 843                 .procname       = "lowmem_reserve_ratio",
 844                 .data           = &sysctl_lowmem_reserve_ratio,
 845                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 846                 .mode           = 0644,
 847                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 848                 .strategy       = &sysctl_intvec,
 849         },
 850         {
 851                 .ctl_name       = VM_DROP_PAGECACHE,
 852                 .procname       = "drop_caches",
 853                 .data           = &sysctl_drop_caches,
 854                 .maxlen         = sizeof(int),
 855                 .mode           = 0644,
 856                 .proc_handler   = drop_caches_sysctl_handler,
 857                 .strategy       = &sysctl_intvec,
 858         },
 859         {
 860                 .ctl_name       = VM_MIN_FREE_KBYTES,
 861                 .procname       = "min_free_kbytes",
 862                 .data           = &min_free_kbytes,
 863                 .maxlen         = sizeof(min_free_kbytes),
 864                 .mode           = 0644,
 865                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 866                 .strategy       = &sysctl_intvec,
 867                 .extra1         = &zero,
 868         },
 869         {
 870                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 871                 .procname       = "percpu_pagelist_fraction",
 872                 .data           = &percpu_pagelist_fraction,
 873                 .maxlen         = sizeof(percpu_pagelist_fraction),
 874                 .mode           = 0644,
 875                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 876                 .strategy       = &sysctl_intvec,
 877                 .extra1         = &min_percpu_pagelist_fract,
 878         },
 879 #ifdef CONFIG_MMU
 880         {
 881                 .ctl_name       = VM_MAX_MAP_COUNT,
 882                 .procname       = "max_map_count",
 883                 .data           = &sysctl_max_map_count,
 884                 .maxlen         = sizeof(sysctl_max_map_count),
 885                 .mode           = 0644,
 886                 .proc_handler   = &proc_dointvec
 887         },
 888 #endif
 889         {
 890                 .ctl_name       = VM_LAPTOP_MODE,
 891                 .procname       = "laptop_mode",
 892                 .data           = &laptop_mode,
 893                 .maxlen         = sizeof(laptop_mode),
 894                 .mode           = 0644,
 895                 .proc_handler   = &proc_dointvec_jiffies,
 896                 .strategy       = &sysctl_jiffies,
 897         },
 898         {
 899                 .ctl_name       = VM_BLOCK_DUMP,
 900                 .procname       = "block_dump",
 901                 .data           = &block_dump,
 902                 .maxlen         = sizeof(block_dump),
 903                 .mode           = 0644,
 904                 .proc_handler   = &proc_dointvec,
 905                 .strategy       = &sysctl_intvec,
 906                 .extra1         = &zero,
 907         },
 908         {
 909                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 910                 .procname       = "vfs_cache_pressure",
 911                 .data           = &sysctl_vfs_cache_pressure,
 912                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 913                 .mode           = 0644,
 914                 .proc_handler   = &proc_dointvec,
 915                 .strategy       = &sysctl_intvec,
 916                 .extra1         = &zero,
 917         },
 918 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 919         {
 920                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 921                 .procname       = "legacy_va_layout",
 922                 .data           = &sysctl_legacy_va_layout,
 923                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 924                 .mode           = 0644,
 925                 .proc_handler   = &proc_dointvec,
 926                 .strategy       = &sysctl_intvec,
 927                 .extra1         = &zero,
 928         },
 929 #endif
 930 #ifdef CONFIG_SWAP
 931         {
 932                 .ctl_name       = VM_SWAP_TOKEN_TIMEOUT,
 933                 .procname       = "swap_token_timeout",
 934                 .data           = &swap_token_default_timeout,
 935                 .maxlen         = sizeof(swap_token_default_timeout),
 936                 .mode           = 0644,
 937                 .proc_handler   = &proc_dointvec_jiffies,
 938                 .strategy       = &sysctl_jiffies,
 939         },
 940 #endif
 941 #ifdef CONFIG_NUMA
 942         {
 943                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 944                 .procname       = "zone_reclaim_mode",
 945                 .data           = &zone_reclaim_mode,
 946                 .maxlen         = sizeof(zone_reclaim_mode),
 947                 .mode           = 0644,
 948                 .proc_handler   = &proc_dointvec,
 949                 .strategy       = &sysctl_intvec,
 950                 .extra1         = &zero,
 951         },
 952         {
 953                 .ctl_name       = VM_MIN_UNMAPPED,
 954                 .procname       = "min_unmapped_ratio",
 955                 .data           = &sysctl_min_unmapped_ratio,
 956                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 957                 .mode           = 0644,
 958                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 959                 .strategy       = &sysctl_intvec,
 960                 .extra1         = &zero,
 961                 .extra2         = &one_hundred,
 962         },
 963 #endif
 964 #ifdef CONFIG_X86_32
 965         {
 966                 .ctl_name       = VM_VDSO_ENABLED,
 967                 .procname       = "vdso_enabled",
 968                 .data           = &vdso_enabled,
 969                 .maxlen         = sizeof(vdso_enabled),
 970                 .mode           = 0644,
 971                 .proc_handler   = &proc_dointvec,
 972                 .strategy       = &sysctl_intvec,
 973                 .extra1         = &zero,
 974         },
 975 #endif
 976         { .ctl_name = 0 }
 977 };
 978
 979 static ctl_table fs_table[] = {
 980         {
 981                 .ctl_name       = FS_NRINODE,
 982                 .procname       = "inode-nr",
 983                 .data           = &inodes_stat,
 984                 .maxlen         = 2*sizeof(int),
 985                 .mode           = 0444,
 986                 .proc_handler   = &proc_dointvec,
 987         },
 988         {
 989                 .ctl_name       = FS_STATINODE,
 990                 .procname       = "inode-state",
 991                 .data           = &inodes_stat,
 992                 .maxlen         = 7*sizeof(int),
 993                 .mode           = 0444,
 994                 .proc_handler   = &proc_dointvec,
 995         },
 996         {
 997                 .ctl_name       = FS_NRFILE,
 998                 .procname       = "file-nr",
 999                 .data           = &files_stat,
1000                 .maxlen         = 3*sizeof(int),
1001                 .mode           = 0444,
1002                 .proc_handler   = &proc_nr_files,
1003         },
1004         {
1005                 .ctl_name       = FS_MAXFILE,
1006                 .procname       = "file-max",
1007                 .data           = &files_stat.max_files,
1008                 .maxlen         = sizeof(int),
1009                 .mode           = 0644,
1010                 .proc_handler   = &proc_dointvec,
1011         },
1012         {
1013                 .ctl_name       = FS_DENTRY,
1014                 .procname       = "dentry-state",
1015                 .data           = &dentry_stat,
1016                 .maxlen         = 6*sizeof(int),
1017                 .mode           = 0444,
1018                 .proc_handler   = &proc_dointvec,
1019         },
1020         {
1021                 .ctl_name       = FS_OVERFLOWUID,
1022                 .procname       = "overflowuid",
1023                 .data           = &fs_overflowuid,
1024                 .maxlen         = sizeof(int),
1025                 .mode           = 0644,
1026                 .proc_handler   = &proc_dointvec_minmax,
1027                 .strategy       = &sysctl_intvec,
1028                 .extra1         = &minolduid,
1029                 .extra2         = &maxolduid,
1030         },
1031         {
1032                 .ctl_name       = FS_OVERFLOWGID,
1033                 .procname       = "overflowgid",
1034                 .data           = &fs_overflowgid,
1035                 .maxlen         = sizeof(int),
1036                 .mode           = 0644,
1037                 .proc_handler   = &proc_dointvec_minmax,
1038                 .strategy       = &sysctl_intvec,
1039                 .extra1         = &minolduid,
1040                 .extra2         = &maxolduid,
1041         },
1042         {
1043                 .ctl_name       = FS_LEASES,
1044                 .procname       = "leases-enable",
1045                 .data           = &leases_enable,
1046                 .maxlen         = sizeof(int),
1047                 .mode           = 0644,
1048                 .proc_handler   = &proc_dointvec,
1049         },
1050 #ifdef CONFIG_DNOTIFY
1051         {
1052                 .ctl_name       = FS_DIR_NOTIFY,
1053                 .procname       = "dir-notify-enable",
1054                 .data           = &dir_notify_enable,
1055                 .maxlen         = sizeof(int),
1056                 .mode           = 0644,
1057                 .proc_handler   = &proc_dointvec,
1058         },
1059 #endif
1060 #ifdef CONFIG_MMU
1061         {
1062                 .ctl_name       = FS_LEASE_TIME,
1063                 .procname       = "lease-break-time",
1064                 .data           = &lease_break_time,
1065                 .maxlen         = sizeof(int),
1066                 .mode           = 0644,
1067                 .proc_handler   = &proc_dointvec,
1068         },
1069         {
1070                 .ctl_name       = FS_AIO_NR,
1071                 .procname       = "aio-nr",
1072                 .data           = &aio_nr,
1073                 .maxlen         = sizeof(aio_nr),
1074                 .mode           = 0444,
1075                 .proc_handler   = &proc_doulongvec_minmax,
1076         },
1077         {
1078                 .ctl_name       = FS_AIO_MAX_NR,
1079                 .procname       = "aio-max-nr",
1080                 .data           = &aio_max_nr,
1081                 .maxlen         = sizeof(aio_max_nr),
1082                 .mode           = 0644,
1083                 .proc_handler   = &proc_doulongvec_minmax,
1084         },
1085 #ifdef CONFIG_INOTIFY_USER
1086         {
1087                 .ctl_name       = FS_INOTIFY,
1088                 .procname       = "inotify",
1089                 .mode           = 0555,
1090                 .child          = inotify_table,
1091         },
1092 #endif
1093 #endif
1094         {
1095                 .ctl_name       = KERN_SETUID_DUMPABLE,
1096                 .procname       = "suid_dumpable",
1097                 .data           = &suid_dumpable,
1098                 .maxlen         = sizeof(int),
1099                 .mode           = 0644,
1100                 .proc_handler   = &proc_dointvec,
1101         },
1102         { .ctl_name = 0 }
1103 };
1104
1105 static ctl_table debug_table[] = {
1106         { .ctl_name = 0 }
1107 };
1108
1109 static ctl_table dev_table[] = {
1110         { .ctl_name = 0 }
1111 };
1112
1113 extern void init_irq_proc (void);
1114
1115 static DEFINE_SPINLOCK(sysctl_lock);
1116
1117 /* called under sysctl_lock */
1118 static int use_table(struct ctl_table_header *p)
1119 {
1120         if (unlikely(p->unregistering))
1121                 return 0;
1122         p->used++;
1123         return 1;
1124 }
1125
1126 /* called under sysctl_lock */
1127 static void unuse_table(struct ctl_table_header *p)
1128 {
1129         if (!--p->used)
1130                 if (unlikely(p->unregistering))
1131                         complete(p->unregistering);
1132 }
1133
1134 /* called under sysctl_lock, will reacquire if has to wait */
1135 static void start_unregistering(struct ctl_table_header *p)
1136 {
1137         /*
1138          * if p->used is 0, nobody will ever touch that entry again;
1139          * we'll eliminate all paths to it before dropping sysctl_lock
1140          */
1141         if (unlikely(p->used)) {
1142                 struct completion wait;
1143                 init_completion(&wait);
1144                 p->unregistering = &wait;
1145                 spin_unlock(&sysctl_lock);
1146                 wait_for_completion(&wait);
1147                 spin_lock(&sysctl_lock);
1148         }
1149         /*
1150          * do not remove from the list until nobody holds it; walking the
1151          * list in do_sysctl() relies on that.
1152          */
1153         list_del_init(&p->ctl_entry);
1154 }
1155
1156 void __init sysctl_init(void)
1157 {
1158 #ifdef CONFIG_PROC_FS
1159         register_proc_table(root_table, proc_sys_root, &root_table_header);
1160         init_irq_proc();
1161 #endif
1162 }
1163
1164 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1165                void __user *newval, size_t newlen)
1166 {
1167         struct list_head *tmp;
1168         int error = -ENOTDIR;
1169
1170         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1171                 return -ENOTDIR;
1172         if (oldval) {
1173                 int old_len;
1174                 if (!oldlenp || get_user(old_len, oldlenp))
1175                         return -EFAULT;
1176         }
1177         spin_lock(&sysctl_lock);
1178         tmp = &root_table_header.ctl_entry;
1179         do {
1180                 struct ctl_table_header *head =
1181                         list_entry(tmp, struct ctl_table_header, ctl_entry);
1182                 void *context = NULL;
1183
1184                 if (!use_table(head))
1185                         continue;
1186
1187                 spin_unlock(&sysctl_lock);
1188
1189                 error = parse_table(name, nlen, oldval, oldlenp,
1190                                         newval, newlen, head->ctl_table,
1191                                         &context);
1192                 kfree(context);
1193
1194                 spin_lock(&sysctl_lock);
1195                 unuse_table(head);
1196                 if (error != -ENOTDIR)
1197                         break;
1198         } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1199         spin_unlock(&sysctl_lock);
1200         return error;
1201 }
1202
1203 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1204 {
1205         struct __sysctl_args tmp;
1206         int error;
1207
1208         if (copy_from_user(&tmp, args, sizeof(tmp)))
1209                 return -EFAULT;
1210
1211         lock_kernel();
1212         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1213                           tmp.newval, tmp.newlen);
1214         unlock_kernel();
1215         return error;
1216 }
1217
1218 /*
1219  * ctl_perm does NOT grant the superuser all rights automatically, because
1220  * some sysctl variables are readonly even to root.
1221  */
1222
1223 static int test_perm(int mode, int op)
1224 {
1225         if (!current->euid)
1226                 mode >>= 6;
1227         else if (in_egroup_p(0))
1228                 mode >>= 3;
1229         if ((mode & op & 0007) == op)
1230                 return 0;
1231         return -EACCES;
1232 }
1233
1234 static inline int ctl_perm(ctl_table *table, int op)
1235 {
1236         int error;
1237         error = security_sysctl(table, op);
1238         if (error)
1239                 return error;
1240         return test_perm(table->mode, op);
1241 }
1242
1243 static int parse_table(int __user *name, int nlen,
1244                        void __user *oldval, size_t __user *oldlenp,
1245                        void __user *newval, size_t newlen,
1246                        ctl_table *table, void **context)
1247 {
1248         int n;
1249 repeat:
1250         if (!nlen)
1251                 return -ENOTDIR;
1252         if (get_user(n, name))
1253                 return -EFAULT;
1254         for ( ; table->ctl_name; table++) {
1255                 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1256                         int error;
1257                         if (table->child) {
1258                                 if (ctl_perm(table, 001))
1259                                         return -EPERM;
1260                                 if (table->strategy) {
1261                                         error = table->strategy(
1262                                                 table, name, nlen,
1263                                                 oldval, oldlenp,
1264                                                 newval, newlen, context);
1265                                         if (error)
1266                                                 return error;
1267                                 }
1268                                 name++;
1269                                 nlen--;
1270                                 table = table->child;
1271                                 goto repeat;
1272                         }
1273                         error = do_sysctl_strategy(table, name, nlen,
1274                                                    oldval, oldlenp,
1275                                                    newval, newlen, context);
1276                         return error;
1277                 }
1278         }
1279         return -ENOTDIR;
1280 }
1281
1282 /* Perform the actual read/write of a sysctl table entry. */
1283 int do_sysctl_strategy (ctl_table *table,
1284                         int __user *name, int nlen,
1285                         void __user *oldval, size_t __user *oldlenp,
1286                         void __user *newval, size_t newlen, void **context)
1287 {
1288         int op = 0, rc;
1289         size_t len;
1290
1291         if (oldval)
1292                 op |= 004;
1293         if (newval)
1294                 op |= 002;
1295         if (ctl_perm(table, op))
1296                 return -EPERM;
1297
1298         if (table->strategy) {
1299                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1300                                      newval, newlen, context);
1301                 if (rc < 0)
1302                         return rc;
1303                 if (rc > 0)
1304                         return 0;
1305         }
1306
1307         /* If there is no strategy routine, or if the strategy returns
1308          * zero, proceed with automatic r/w */
1309         if (table->data && table->maxlen) {
1310                 if (oldval && oldlenp) {
1311                         if (get_user(len, oldlenp))
1312                                 return -EFAULT;
1313                         if (len) {
1314                                 if (len > table->maxlen)
1315                                         len = table->maxlen;
1316                                 if(copy_to_user(oldval, table->data, len))
1317                                         return -EFAULT;
1318                                 if(put_user(len, oldlenp))
1319                                         return -EFAULT;
1320                         }
1321                 }
1322                 if (newval && newlen) {
1323                         len = newlen;
1324                         if (len > table->maxlen)
1325                                 len = table->maxlen;
1326                         if(copy_from_user(table->data, newval, len))
1327                                 return -EFAULT;
1328                 }
1329         }
1330         return 0;
1331 }
1332
1333 /**
1334  * register_sysctl_table - register a sysctl hierarchy
1335  * @table: the top-level table structure
1336  * @insert_at_head: whether the entry should be inserted in front or at the end
1337  *
1338  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1339  * array. An entry with a ctl_name of 0 terminates the table.
1340  *
1341  * The members of the &ctl_table structure are used as follows:
1342  *
1343  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1344  *            must be unique within that level of sysctl
1345  *
1346  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1347  *            enter a sysctl file
1348  *
1349  * data - a pointer to data for use by proc_handler
1350  *
1351  * maxlen - the maximum size in bytes of the data
1352  *
1353  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1354  *
1355  * child - a pointer to the child sysctl table if this entry is a directory, or
1356  *         %NULL.
1357  *
1358  * proc_handler - the text handler routine (described below)
1359  *
1360  * strategy - the strategy routine (described below)
1361  *
1362  * de - for internal use by the sysctl routines
1363  *
1364  * extra1, extra2 - extra pointers usable by the proc handler routines
1365  *
1366  * Leaf nodes in the sysctl tree will be represented by a single file
1367  * under /proc; non-leaf nodes will be represented by directories.
1368  *
1369  * sysctl(2) can automatically manage read and write requests through
1370  * the sysctl table.  The data and maxlen fields of the ctl_table
1371  * struct enable minimal validation of the values being written to be
1372  * performed, and the mode field allows minimal authentication.
1373  *
1374  * More sophisticated management can be enabled by the provision of a
1375  * strategy routine with the table entry.  This will be called before
1376  * any automatic read or write of the data is performed.
1377  *
1378  * The strategy routine may return
1379  *
1380  * < 0 - Error occurred (error is passed to user process)
1381  *
1382  * 0   - OK - proceed with automatic read or write.
1383  *
1384  * > 0 - OK - read or write has been done by the strategy routine, so
1385  *       return immediately.
1386  *
1387  * There must be a proc_handler routine for any terminal nodes
1388  * mirrored under /proc/sys (non-terminals are handled by a built-in
1389  * directory handler).  Several default handlers are available to
1390  * cover common cases -
1391  *
1392  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1393  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1394  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1395  *
1396  * It is the handler's job to read the input buffer from user memory
1397  * and process it. The handler should return 0 on success.
1398  *
1399  * This routine returns %NULL on a failure to register, and a pointer
1400  * to the table header on success.
1401  */
1402 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1403                                                int insert_at_head)
1404 {
1405         struct ctl_table_header *tmp;
1406         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1407         if (!tmp)
1408                 return NULL;
1409         tmp->ctl_table = table;
1410         INIT_LIST_HEAD(&tmp->ctl_entry);
1411         tmp->used = 0;
1412         tmp->unregistering = NULL;
1413         spin_lock(&sysctl_lock);
1414         if (insert_at_head)
1415                 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1416         else
1417                 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1418         spin_unlock(&sysctl_lock);
1419 #ifdef CONFIG_PROC_FS
1420         register_proc_table(table, proc_sys_root, tmp);
1421 #endif
1422         return tmp;
1423 }
1424
1425 /**
1426  * unregister_sysctl_table - unregister a sysctl table hierarchy
1427  * @header: the header returned from register_sysctl_table
1428  *
1429  * Unregisters the sysctl table and all children. proc entries may not
1430  * actually be removed until they are no longer used by anyone.
1431  */
1432 void unregister_sysctl_table(struct ctl_table_header * header)
1433 {
1434         might_sleep();
1435         spin_lock(&sysctl_lock);
1436         start_unregistering(header);
1437 #ifdef CONFIG_PROC_FS
1438         unregister_proc_table(header->ctl_table, proc_sys_root);
1439 #endif
1440         spin_unlock(&sysctl_lock);
1441         kfree(header);
1442 }
1443
1444 /*
1445  * /proc/sys support
1446  */
1447
1448 #ifdef CONFIG_PROC_FS
1449
1450 /* Scan the sysctl entries in table and add them all into /proc */
1451 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1452 {
1453         struct proc_dir_entry *de;
1454         int len;
1455         mode_t mode;
1456
1457         for (; table->ctl_name; table++) {
1458                 /* Can't do anything without a proc name. */
1459                 if (!table->procname)
1460                         continue;
1461                 /* Maybe we can't do anything with it... */
1462                 if (!table->proc_handler && !table->child) {
1463                         printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1464                                 table->procname);
1465                         continue;
1466                 }
1467
1468                 len = strlen(table->procname);
1469                 mode = table->mode;
1470
1471                 de = NULL;
1472                 if (table->proc_handler)
1473                         mode |= S_IFREG;
1474                 else {
1475                         mode |= S_IFDIR;
1476                         for (de = root->subdir; de; de = de->next) {
1477                                 if (proc_match(len, table->procname, de))
1478                                         break;
1479                         }
1480                         /* If the subdir exists already, de is non-NULL */
1481                 }
1482
1483                 if (!de) {
1484                         de = create_proc_entry(table->procname, mode, root);
1485                         if (!de)
1486                                 continue;
1487                         de->set = set;
1488                         de->data = (void *) table;
1489                         if (table->proc_handler)
1490                                 de->proc_fops = &proc_sys_file_operations;
1491                 }
1492                 table->de = de;
1493                 if (de->mode & S_IFDIR)
1494                         register_proc_table(table->child, de, set);
1495         }
1496 }
1497
1498 /*
1499  * Unregister a /proc sysctl table and any subdirectories.
1500  */
1501 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1502 {
1503         struct proc_dir_entry *de;
1504         for (; table->ctl_name; table++) {
1505                 if (!(de = table->de))
1506                         continue;
1507                 if (de->mode & S_IFDIR) {
1508                         if (!table->child) {
1509                                 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1510                                 continue;
1511                         }
1512                         unregister_proc_table(table->child, de);
1513
1514                         /* Don't unregister directories which still have entries.. */
1515                         if (de->subdir)
1516                                 continue;
1517                 }
1518
1519                 /*
1520                  * In any case, mark the entry as goner; we'll keep it
1521                  * around if it's busy, but we'll know to do nothing with
1522                  * its fields.  We are under sysctl_lock here.
1523                  */
1524                 de->data = NULL;
1525
1526                 /* Don't unregister proc entries that are still being used.. */
1527                 if (atomic_read(&de->count))
1528                         continue;
1529
1530                 table->de = NULL;
1531                 remove_proc_entry(table->procname, root);
1532         }
1533 }
1534
1535 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1536                           size_t count, loff_t *ppos)
1537 {
1538         int op;
1539         struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
1540         struct ctl_table *table;
1541         size_t res;
1542         ssize_t error = -ENOTDIR;
1543
1544         spin_lock(&sysctl_lock);
1545         if (de && de->data && use_table(de->set)) {
1546                 /*
1547                  * at that point we know that sysctl was not unregistered
1548                  * and won't be until we finish
1549                  */
1550                 spin_unlock(&sysctl_lock);
1551                 table = (struct ctl_table *) de->data;
1552                 if (!table || !table->proc_handler)
1553                         goto out;
1554                 error = -EPERM;
1555                 op = (write ? 002 : 004);
1556                 if (ctl_perm(table, op))
1557                         goto out;
1558
1559                 /* careful: calling conventions are nasty here */
1560                 res = count;
1561                 error = (*table->proc_handler)(table, write, file,
1562                                                 buf, &res, ppos);
1563                 if (!error)
1564                         error = res;
1565         out:
1566                 spin_lock(&sysctl_lock);
1567                 unuse_table(de->set);
1568         }
1569         spin_unlock(&sysctl_lock);
1570         return error;
1571 }
1572
1573 static int proc_opensys(struct inode *inode, struct file *file)
1574 {
1575         if (file->f_mode & FMODE_WRITE) {
1576                 /*
1577                  * sysctl entries that are not writable,
1578                  * are _NOT_ writable, capabilities or not.
1579                  */
1580                 if (!(inode->i_mode & S_IWUSR))
1581                         return -EPERM;
1582         }
1583
1584         return 0;
1585 }
1586
1587 static ssize_t proc_readsys(struct file * file, char __user * buf,
1588                             size_t count, loff_t *ppos)
1589 {
1590         return do_rw_proc(0, file, buf, count, ppos);
1591 }
1592
1593 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1594                              size_t count, loff_t *ppos)
1595 {
1596         return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1597 }
1598
1599 /**
1600  * proc_dostring - read a string sysctl
1601  * @table: the sysctl table
1602  * @write: %TRUE if this is a write to the sysctl file
1603  * @filp: the file structure
1604  * @buffer: the user buffer
1605  * @lenp: the size of the user buffer
1606  * @ppos: file position
1607  *
1608  * Reads/writes a string from/to the user buffer. If the kernel
1609  * buffer provided is not large enough to hold the string, the
1610  * string is truncated. The copied string is %NULL-terminated.
1611  * If the string is being read by the user process, it is copied
1612  * and a newline '\n' is added. It is truncated if the buffer is
1613  * not large enough.
1614  *
1615  * Returns 0 on success.
1616  */
1617 int proc_dostring(ctl_table *table, int write, struct file *filp,
1618                   void __user *buffer, size_t *lenp, loff_t *ppos)
1619 {
1620         size_t len;
1621         char __user *p;
1622         char c;
1623
1624         if (!table->data || !table->maxlen || !*lenp ||
1625             (*ppos && !write)) {
1626                 *lenp = 0;
1627                 return 0;
1628         }
1629
1630         if (write) {
1631                 len = 0;
1632                 p = buffer;
1633                 while (len < *lenp) {
1634                         if (get_user(c, p++))
1635                                 return -EFAULT;
1636                         if (c == 0 || c == '\n')
1637                                 break;
1638                         len++;
1639                 }
1640                 if (len >= table->maxlen)
1641                         len = table->maxlen-1;
1642                 if(copy_from_user(table->data, buffer, len))
1643                         return -EFAULT;
1644                 ((char *) table->data)[len] = 0;
1645                 *ppos += *lenp;
1646         } else {
1647                 len = strlen(table->data);
1648                 if (len > table->maxlen)
1649                         len = table->maxlen;
1650                 if (len > *lenp)
1651                         len = *lenp;
1652                 if (len)
1653                         if(copy_to_user(buffer, table->data, len))
1654                                 return -EFAULT;
1655                 if (len < *lenp) {
1656                         if(put_user('\n', ((char __user *) buffer) + len))
1657                                 return -EFAULT;
1658                         len++;
1659                 }
1660                 *lenp = len;
1661                 *ppos += len;
1662         }
1663         return 0;
1664 }
1665
1666 /*
1667  *      Special case of dostring for the UTS structure. This has locks
1668  *      to observe. Should this be in kernel/sys.c ????
1669  */
1670
1671 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1672                   void __user *buffer, size_t *lenp, loff_t *ppos)
1673 {
1674         int r;
1675
1676         if (!write) {
1677                 down_read(&uts_sem);
1678                 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1679                 up_read(&uts_sem);
1680         } else {
1681                 down_write(&uts_sem);
1682                 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1683                 up_write(&uts_sem);
1684         }
1685         return r;
1686 }
1687
1688 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1689                                  int *valp,
1690                                  int write, void *data)
1691 {
1692         if (write) {
1693                 *valp = *negp ? -*lvalp : *lvalp;
1694         } else {
1695                 int val = *valp;
1696                 if (val < 0) {
1697                         *negp = -1;
1698                         *lvalp = (unsigned long)-val;
1699                 } else {
1700                         *negp = 0;
1701                         *lvalp = (unsigned long)val;
1702                 }
1703         }
1704         return 0;
1705 }
1706
1707 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1708                   void __user *buffer, size_t *lenp, loff_t *ppos,
1709                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1710                               int write, void *data),
1711                   void *data)
1712 {
1713 #define TMPBUFLEN 21
1714         int *i, vleft, first=1, neg, val;
1715         unsigned long lval;
1716         size_t left, len;
1717
1718         char buf[TMPBUFLEN], *p;
1719         char __user *s = buffer;
1720
1721         if (!table->data || !table->maxlen || !*lenp ||
1722             (*ppos && !write)) {
1723                 *lenp = 0;
1724                 return 0;
1725         }
1726
1727         i = (int *) table->data;
1728         vleft = table->maxlen / sizeof(*i);
1729         left = *lenp;
1730
1731         if (!conv)
1732                 conv = do_proc_dointvec_conv;
1733
1734         for (; left && vleft--; i++, first=0) {
1735                 if (write) {
1736                         while (left) {
1737                                 char c;
1738                                 if (get_user(c, s))
1739                                         return -EFAULT;
1740                                 if (!isspace(c))
1741                                         break;
1742                                 left--;
1743                                 s++;
1744                         }
1745                         if (!left)
1746                                 break;
1747                         neg = 0;
1748                         len = left;
1749                         if (len > sizeof(buf) - 1)
1750                                 len = sizeof(buf) - 1;
1751                         if (copy_from_user(buf, s, len))
1752                                 return -EFAULT;
1753                         buf[len] = 0;
1754                         p = buf;
1755                         if (*p == '-' && left > 1) {
1756                                 neg = 1;
1757                                 left--, p++;
1758                         }
1759                         if (*p < '0' || *p > '9')
1760                                 break;
1761
1762                         lval = simple_strtoul(p, &p, 0);
1763
1764                         len = p-buf;
1765                         if ((len < left) && *p && !isspace(*p))
1766                                 break;
1767                         if (neg)
1768                                 val = -val;
1769                         s += len;
1770                         left -= len;
1771
1772                         if (conv(&neg, &lval, i, 1, data))
1773                                 break;
1774                 } else {
1775                         p = buf;
1776                         if (!first)
1777                                 *p++ = '\t';
1778
1779                         if (conv(&neg, &lval, i, 0, data))
1780                                 break;
1781
1782                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1783                         len = strlen(buf);
1784                         if (len > left)
1785                                 len = left;
1786                         if(copy_to_user(s, buf, len))
1787                                 return -EFAULT;
1788                         left -= len;
1789                         s += len;
1790                 }
1791         }
1792
1793         if (!write && !first && left) {
1794                 if(put_user('\n', s))
1795                         return -EFAULT;
1796                 left--, s++;
1797         }
1798         if (write) {
1799                 while (left) {
1800                         char c;
1801                         if (get_user(c, s++))
1802                                 return -EFAULT;
1803                         if (!isspace(c))
1804                                 break;
1805                         left--;
1806                 }
1807         }
1808         if (write && first)
1809                 return -EINVAL;
1810         *lenp -= left;
1811         *ppos += *lenp;
1812         return 0;
1813 #undef TMPBUFLEN
1814 }
1815
1816 /**
1817  * proc_dointvec - read a vector of integers
1818  * @table: the sysctl table
1819  * @write: %TRUE if this is a write to the sysctl file
1820  * @filp: the file structure
1821  * @buffer: the user buffer
1822  * @lenp: the size of the user buffer
1823  * @ppos: file position
1824  *
1825  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1826  * values from/to the user buffer, treated as an ASCII string.
1827  *
1828  * Returns 0 on success.
1829  */
1830 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1831                      void __user *buffer, size_t *lenp, loff_t *ppos)
1832 {
1833     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1834                             NULL,NULL);
1835 }
1836
1837 #define OP_SET  0
1838 #define OP_AND  1
1839 #define OP_OR   2
1840 #define OP_MAX  3
1841 #define OP_MIN  4
1842
1843 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1844                                       int *valp,
1845                                       int write, void *data)
1846 {
1847         int op = *(int *)data;
1848         if (write) {
1849                 int val = *negp ? -*lvalp : *lvalp;
1850                 switch(op) {
1851                 case OP_SET:    *valp = val; break;
1852                 case OP_AND:    *valp &= val; break;
1853                 case OP_OR:     *valp |= val; break;
1854                 case OP_MAX:    if(*valp < val)
1855                                         *valp = val;
1856                                 break;
1857                 case OP_MIN:    if(*valp > val)
1858                                 *valp = val;
1859                                 break;
1860                 }
1861         } else {
1862                 int val = *valp;
1863                 if (val < 0) {
1864                         *negp = -1;
1865                         *lvalp = (unsigned long)-val;
1866                 } else {
1867                         *negp = 0;
1868                         *lvalp = (unsigned long)val;
1869                 }
1870         }
1871         return 0;
1872 }
1873
1874 /*
1875  *      init may raise the set.
1876  */
1877
1878 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1879                         void __user *buffer, size_t *lenp, loff_t *ppos)
1880 {
1881         int op;
1882
1883         if (!capable(CAP_SYS_MODULE)) {
1884                 return -EPERM;
1885         }
1886
1887         op = (current->pid == 1) ? OP_SET : OP_AND;
1888         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1889                                 do_proc_dointvec_bset_conv,&op);
1890 }
1891
1892 struct do_proc_dointvec_minmax_conv_param {
1893         int *min;
1894         int *max;
1895 };
1896
1897 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1898                                         int *valp,
1899                                         int write, void *data)
1900 {
1901         struct do_proc_dointvec_minmax_conv_param *param = data;
1902         if (write) {
1903                 int val = *negp ? -*lvalp : *lvalp;
1904                 if ((param->min && *param->min > val) ||
1905                     (param->max && *param->max < val))
1906                         return -EINVAL;
1907                 *valp = val;
1908         } else {
1909                 int val = *valp;
1910                 if (val < 0) {
1911                         *negp = -1;
1912                         *lvalp = (unsigned long)-val;
1913                 } else {
1914                         *negp = 0;
1915                         *lvalp = (unsigned long)val;
1916                 }
1917         }
1918         return 0;
1919 }
1920
1921 /**
1922  * proc_dointvec_minmax - read a vector of integers with min/max values
1923  * @table: the sysctl table
1924  * @write: %TRUE if this is a write to the sysctl file
1925  * @filp: the file structure
1926  * @buffer: the user buffer
1927  * @lenp: the size of the user buffer
1928  * @ppos: file position
1929  *
1930  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1931  * values from/to the user buffer, treated as an ASCII string.
1932  *
1933  * This routine will ensure the values are within the range specified by
1934  * table->extra1 (min) and table->extra2 (max).
1935  *
1936  * Returns 0 on success.
1937  */
1938 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1939                   void __user *buffer, size_t *lenp, loff_t *ppos)
1940 {
1941         struct do_proc_dointvec_minmax_conv_param param = {
1942                 .min = (int *) table->extra1,
1943                 .max = (int *) table->extra2,
1944         };
1945         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1946                                 do_proc_dointvec_minmax_conv, &param);
1947 }
1948
1949 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1950                                      struct file *filp,
1951                                      void __user *buffer,
1952                                      size_t *lenp, loff_t *ppos,
1953                                      unsigned long convmul,
1954                                      unsigned long convdiv)
1955 {
1956 #define TMPBUFLEN 21
1957         unsigned long *i, *min, *max, val;
1958         int vleft, first=1, neg;
1959         size_t len, left;
1960         char buf[TMPBUFLEN], *p;
1961         char __user *s = buffer;
1962
1963         if (!table->data || !table->maxlen || !*lenp ||
1964             (*ppos && !write)) {
1965                 *lenp = 0;
1966                 return 0;
1967         }
1968
1969         i = (unsigned long *) table->data;
1970         min = (unsigned long *) table->extra1;
1971         max = (unsigned long *) table->extra2;
1972         vleft = table->maxlen / sizeof(unsigned long);
1973         left = *lenp;
1974
1975         for (; left && vleft--; i++, min++, max++, first=0) {
1976                 if (write) {
1977                         while (left) {
1978                                 char c;
1979                                 if (get_user(c, s))
1980                                         return -EFAULT;
1981                                 if (!isspace(c))
1982                                         break;
1983                                 left--;
1984                                 s++;
1985                         }
1986                         if (!left)
1987                                 break;
1988                         neg = 0;
1989                         len = left;
1990                         if (len > TMPBUFLEN-1)
1991                                 len = TMPBUFLEN-1;
1992                         if (copy_from_user(buf, s, len))
1993                                 return -EFAULT;
1994                         buf[len] = 0;
1995                         p = buf;
1996                         if (*p == '-' && left > 1) {
1997                                 neg = 1;
1998                                 left--, p++;
1999                         }
2000                         if (*p < '0' || *p > '9')
2001                                 break;
2002                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2003                         len = p-buf;
2004                         if ((len < left) && *p && !isspace(*p))
2005                                 break;
2006                         if (neg)
2007                                 val = -val;
2008                         s += len;
2009                         left -= len;
2010
2011                         if(neg)
2012                                 continue;
2013                         if ((min && val < *min) || (max && val > *max))
2014                                 continue;
2015                         *i = val;
2016                 } else {
2017                         p = buf;
2018                         if (!first)
2019                                 *p++ = '\t';
2020                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2021                         len = strlen(buf);
2022                         if (len > left)
2023                                 len = left;
2024                         if(copy_to_user(s, buf, len))
2025                                 return -EFAULT;
2026                         left -= len;
2027                         s += len;
2028                 }
2029         }
2030
2031         if (!write && !first && left) {
2032                 if(put_user('\n', s))
2033                         return -EFAULT;
2034                 left--, s++;
2035         }
2036         if (write) {
2037                 while (left) {
2038                         char c;
2039                         if (get_user(c, s++))
2040                                 return -EFAULT;
2041                         if (!isspace(c))
2042                                 break;
2043                         left--;
2044                 }
2045         }
2046         if (write && first)
2047                 return -EINVAL;
2048         *lenp -= left;
2049         *ppos += *lenp;
2050         return 0;
2051 #undef TMPBUFLEN
2052 }
2053
2054 /**
2055  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2056  * @table: the sysctl table
2057  * @write: %TRUE if this is a write to the sysctl file
2058  * @filp: the file structure
2059  * @buffer: the user buffer
2060  * @lenp: the size of the user buffer
2061  * @ppos: file position
2062  *
2063  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2064  * values from/to the user buffer, treated as an ASCII string.
2065  *
2066  * This routine will ensure the values are within the range specified by
2067  * table->extra1 (min) and table->extra2 (max).
2068  *
2069  * Returns 0 on success.
2070  */
2071 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2072                            void __user *buffer, size_t *lenp, loff_t *ppos)
2073 {
2074     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2075 }
2076
2077 /**
2078  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2079  * @table: the sysctl table
2080  * @write: %TRUE if this is a write to the sysctl file
2081  * @filp: the file structure
2082  * @buffer: the user buffer
2083  * @lenp: the size of the user buffer
2084  * @ppos: file position
2085  *
2086  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2087  * values from/to the user buffer, treated as an ASCII string. The values
2088  * are treated as milliseconds, and converted to jiffies when they are stored.
2089  *
2090  * This routine will ensure the values are within the range specified by
2091  * table->extra1 (min) and table->extra2 (max).
2092  *
2093  * Returns 0 on success.
2094  */
2095 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2096                                       struct file *filp,
2097                                       void __user *buffer,
2098                                       size_t *lenp, loff_t *ppos)
2099 {
2100     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2101                                      lenp, ppos, HZ, 1000l);
2102 }
2103
2104
2105 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2106                                          int *valp,
2107                                          int write, void *data)
2108 {
2109         if (write) {
2110                 if (*lvalp > LONG_MAX / HZ)
2111                         return 1;
2112                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2113         } else {
2114                 int val = *valp;
2115                 unsigned long lval;
2116                 if (val < 0) {
2117                         *negp = -1;
2118                         lval = (unsigned long)-val;
2119                 } else {
2120                         *negp = 0;
2121                         lval = (unsigned long)val;
2122                 }
2123                 *lvalp = lval / HZ;
2124         }
2125         return 0;
2126 }
2127
2128 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2129                                                 int *valp,
2130                                                 int write, void *data)
2131 {
2132         if (write) {
2133                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2134                         return 1;
2135                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2136         } else {
2137                 int val = *valp;
2138                 unsigned long lval;
2139                 if (val < 0) {
2140                         *negp = -1;
2141                         lval = (unsigned long)-val;
2142                 } else {
2143                         *negp = 0;
2144                         lval = (unsigned long)val;
2145                 }
2146                 *lvalp = jiffies_to_clock_t(lval);
2147         }
2148         return 0;
2149 }
2150
2151 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2152                                             int *valp,
2153                                             int write, void *data)
2154 {
2155         if (write) {
2156                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2157         } else {
2158                 int val = *valp;
2159                 unsigned long lval;
2160                 if (val < 0) {
2161                         *negp = -1;
2162                         lval = (unsigned long)-val;
2163                 } else {
2164                         *negp = 0;
2165                         lval = (unsigned long)val;
2166                 }
2167                 *lvalp = jiffies_to_msecs(lval);
2168         }
2169         return 0;
2170 }
2171
2172 /**
2173  * proc_dointvec_jiffies - read a vector of integers as seconds
2174  * @table: the sysctl table
2175  * @write: %TRUE if this is a write to the sysctl file
2176  * @filp: the file structure
2177  * @buffer: the user buffer
2178  * @lenp: the size of the user buffer
2179  * @ppos: file position
2180  *
2181  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2182  * values from/to the user buffer, treated as an ASCII string.
2183  * The values read are assumed to be in seconds, and are converted into
2184  * jiffies.
2185  *
2186  * Returns 0 on success.
2187  */
2188 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2189                           void __user *buffer, size_t *lenp, loff_t *ppos)
2190 {
2191     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2192                             do_proc_dointvec_jiffies_conv,NULL);
2193 }
2194
2195 /**
2196  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2197  * @table: the sysctl table
2198  * @write: %TRUE if this is a write to the sysctl file
2199  * @filp: the file structure
2200  * @buffer: the user buffer
2201  * @lenp: the size of the user buffer
2202  * @ppos: pointer to the file position
2203  *
2204  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2205  * values from/to the user buffer, treated as an ASCII string.
2206  * The values read are assumed to be in 1/USER_HZ seconds, and
2207  * are converted into jiffies.
2208  *
2209  * Returns 0 on success.
2210  */
2211 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2212                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2213 {
2214     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2215                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2216 }
2217
2218 /**
2219  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2220  * @table: the sysctl table
2221  * @write: %TRUE if this is a write to the sysctl file
2222  * @filp: the file structure
2223  * @buffer: the user buffer
2224  * @lenp: the size of the user buffer
2225  * @ppos: file position
2226  * @ppos: the current position in the file
2227  *
2228  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2229  * values from/to the user buffer, treated as an ASCII string.
2230  * The values read are assumed to be in 1/1000 seconds, and
2231  * are converted into jiffies.
2232  *
2233  * Returns 0 on success.
2234  */
2235 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2236                              void __user *buffer, size_t *lenp, loff_t *ppos)
2237 {
2238         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2239                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2240 }
2241
2242 #else /* CONFIG_PROC_FS */
2243
2244 int proc_dostring(ctl_table *table, int write, struct file *filp,
2245                   void __user *buffer, size_t *lenp, loff_t *ppos)
2246 {
2247         return -ENOSYS;
2248 }
2249
2250 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2251                             void __user *buffer, size_t *lenp, loff_t *ppos)
2252 {
2253         return -ENOSYS;
2254 }
2255
2256 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2257                   void __user *buffer, size_t *lenp, loff_t *ppos)
2258 {
2259         return -ENOSYS;
2260 }
2261
2262 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2263                         void __user *buffer, size_t *lenp, loff_t *ppos)
2264 {
2265         return -ENOSYS;
2266 }
2267
2268 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2269                     void __user *buffer, size_t *lenp, loff_t *ppos)
2270 {
2271         return -ENOSYS;
2272 }
2273
2274 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2275                     void __user *buffer, size_t *lenp, loff_t *ppos)
2276 {
2277         return -ENOSYS;
2278 }
2279
2280 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2281                     void __user *buffer, size_t *lenp, loff_t *ppos)
2282 {
2283         return -ENOSYS;
2284 }
2285
2286 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2287                              void __user *buffer, size_t *lenp, loff_t *ppos)
2288 {
2289         return -ENOSYS;
2290 }
2291
2292 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2293                     void __user *buffer, size_t *lenp, loff_t *ppos)
2294 {
2295         return -ENOSYS;
2296 }
2297
2298 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2299                                       struct file *filp,
2300                                       void __user *buffer,
2301                                       size_t *lenp, loff_t *ppos)
2302 {
2303     return -ENOSYS;
2304 }
2305
2306
2307 #endif /* CONFIG_PROC_FS */
2308
2309
2310 /*
2311  * General sysctl support routines
2312  */
2313
2314 /* The generic string strategy routine: */
2315 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2316                   void __user *oldval, size_t __user *oldlenp,
2317                   void __user *newval, size_t newlen, void **context)
2318 {
2319         if (!table->data || !table->maxlen)
2320                 return -ENOTDIR;
2321
2322         if (oldval && oldlenp) {
2323                 size_t bufsize;
2324                 if (get_user(bufsize, oldlenp))
2325                         return -EFAULT;
2326                 if (bufsize) {
2327                         size_t len = strlen(table->data), copied;
2328
2329                         /* This shouldn't trigger for a well-formed sysctl */
2330                         if (len > table->maxlen)
2331                                 len = table->maxlen;
2332
2333                         /* Copy up to a max of bufsize-1 bytes of the string */
2334                         copied = (len >= bufsize) ? bufsize - 1 : len;
2335
2336                         if (copy_to_user(oldval, table->data, copied) ||
2337                             put_user(0, (char __user *)(oldval + copied)))
2338                                 return -EFAULT;
2339                         if (put_user(len, oldlenp))
2340                                 return -EFAULT;
2341                 }
2342         }
2343         if (newval && newlen) {
2344                 size_t len = newlen;
2345                 if (len > table->maxlen)
2346                         len = table->maxlen;
2347                 if(copy_from_user(table->data, newval, len))
2348                         return -EFAULT;
2349                 if (len == table->maxlen)
2350                         len--;
2351                 ((char *) table->data)[len] = 0;
2352         }
2353         return 1;
2354 }
2355
2356 /*
2357  * This function makes sure that all of the integers in the vector
2358  * are between the minimum and maximum values given in the arrays
2359  * table->extra1 and table->extra2, respectively.
2360  */
2361 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2362                 void __user *oldval, size_t __user *oldlenp,
2363                 void __user *newval, size_t newlen, void **context)
2364 {
2365
2366         if (newval && newlen) {
2367                 int __user *vec = (int __user *) newval;
2368                 int *min = (int *) table->extra1;
2369                 int *max = (int *) table->extra2;
2370                 size_t length;
2371                 int i;
2372
2373                 if (newlen % sizeof(int) != 0)
2374                         return -EINVAL;
2375
2376                 if (!table->extra1 && !table->extra2)
2377                         return 0;
2378
2379                 if (newlen > table->maxlen)
2380                         newlen = table->maxlen;
2381                 length = newlen / sizeof(int);
2382
2383                 for (i = 0; i < length; i++) {
2384                         int value;
2385                         if (get_user(value, vec + i))
2386                                 return -EFAULT;
2387                         if (min && value < min[i])
2388                                 return -EINVAL;
2389                         if (max && value > max[i])
2390                                 return -EINVAL;
2391                 }
2392         }
2393         return 0;
2394 }
2395
2396 /* Strategy function to convert jiffies to seconds */
2397 int sysctl_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(*(int *)(table->data)/HZ, (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) = new*HZ;
2420         }
2421         return 1;
2422 }
2423
2424 /* Strategy function to convert jiffies to seconds */
2425 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2426                 void __user *oldval, size_t __user *oldlenp,
2427                 void __user *newval, size_t newlen, void **context)
2428 {
2429         if (oldval) {
2430                 size_t olen;
2431                 if (oldlenp) {
2432                         if (get_user(olen, oldlenp))
2433                                 return -EFAULT;
2434                         if (olen!=sizeof(int))
2435                                 return -EINVAL;
2436                 }
2437                 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2438                     (oldlenp && put_user(sizeof(int),oldlenp)))
2439                         return -EFAULT;
2440         }
2441         if (newval && newlen) {
2442                 int new;
2443                 if (newlen != sizeof(int))
2444                         return -EINVAL;
2445                 if (get_user(new, (int __user *)newval))
2446                         return -EFAULT;
2447                 *(int *)(table->data) = msecs_to_jiffies(new);
2448         }
2449         return 1;
2450 }
2451
2452 #else /* CONFIG_SYSCTL */
2453
2454
2455 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2456 {
2457         return -ENOSYS;
2458 }
2459
2460 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2461                   void __user *oldval, size_t __user *oldlenp,
2462                   void __user *newval, size_t newlen, void **context)
2463 {
2464         return -ENOSYS;
2465 }
2466
2467 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2468                 void __user *oldval, size_t __user *oldlenp,
2469                 void __user *newval, size_t newlen, void **context)
2470 {
2471         return -ENOSYS;
2472 }
2473
2474 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2475                 void __user *oldval, size_t __user *oldlenp,
2476                 void __user *newval, size_t newlen, void **context)
2477 {
2478         return -ENOSYS;
2479 }
2480
2481 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2482                 void __user *oldval, size_t __user *oldlenp,
2483                 void __user *newval, size_t newlen, void **context)
2484 {
2485         return -ENOSYS;
2486 }
2487
2488 int proc_dostring(ctl_table *table, int write, struct file *filp,
2489                   void __user *buffer, size_t *lenp, loff_t *ppos)
2490 {
2491         return -ENOSYS;
2492 }
2493
2494 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2495                   void __user *buffer, size_t *lenp, loff_t *ppos)
2496 {
2497         return -ENOSYS;
2498 }
2499
2500 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2501                         void __user *buffer, size_t *lenp, loff_t *ppos)
2502 {
2503         return -ENOSYS;
2504 }
2505
2506 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2507                     void __user *buffer, size_t *lenp, loff_t *ppos)
2508 {
2509         return -ENOSYS;
2510 }
2511
2512 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2513                           void __user *buffer, size_t *lenp, loff_t *ppos)
2514 {
2515         return -ENOSYS;
2516 }
2517
2518 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2519                           void __user *buffer, size_t *lenp, loff_t *ppos)
2520 {
2521         return -ENOSYS;
2522 }
2523
2524 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2525                              void __user *buffer, size_t *lenp, loff_t *ppos)
2526 {
2527         return -ENOSYS;
2528 }
2529
2530 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2531                     void __user *buffer, size_t *lenp, loff_t *ppos)
2532 {
2533         return -ENOSYS;
2534 }
2535
2536 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2537                                       struct file *filp,
2538                                       void __user *buffer,
2539                                       size_t *lenp, loff_t *ppos)
2540 {
2541     return -ENOSYS;
2542 }
2543
2544 struct ctl_table_header * register_sysctl_table(ctl_table * table,
2545                                                 int insert_at_head)
2546 {
2547         return NULL;
2548 }
2549
2550 void unregister_sysctl_table(struct ctl_table_header * table)
2551 {
2552 }
2553
2554 #endif /* CONFIG_SYSCTL */
2555
2556 /*
2557  * No sense putting this after each symbol definition, twice,
2558  * exception granted :-)
2559  */
2560 EXPORT_SYMBOL(proc_dointvec);
2561 EXPORT_SYMBOL(proc_dointvec_jiffies);
2562 EXPORT_SYMBOL(proc_dointvec_minmax);
2563 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2564 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2565 EXPORT_SYMBOL(proc_dostring);
2566 EXPORT_SYMBOL(proc_doulongvec_minmax);
2567 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2568 EXPORT_SYMBOL(register_sysctl_table);
2569 EXPORT_SYMBOL(sysctl_intvec);
2570 EXPORT_SYMBOL(sysctl_jiffies);
2571 EXPORT_SYMBOL(sysctl_ms_jiffies);
2572 EXPORT_SYMBOL(sysctl_string);
2573 EXPORT_SYMBOL(unregister_sysctl_table);