kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/capability.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/capability.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/security.h>
  42 #include <linux/initrd.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50
  51 #include <asm/uaccess.h>
  52 #include <asm/processor.h>
  53
  54 #ifdef CONFIG_X86
  55 #include <asm/nmi.h>
  56 #include <asm/stacktrace.h>
  57 #endif
  58
  59 #if defined(CONFIG_SYSCTL)
  60
  61 /* External variables not in a header file. */
  62 extern int C_A_D;
  63 extern int print_fatal_signals;
  64 extern int sysctl_overcommit_memory;
  65 extern int sysctl_overcommit_ratio;
  66 extern int sysctl_panic_on_oom;
  67 extern int max_threads;
  68 extern int core_uses_pid;
  69 extern int suid_dumpable;
  70 extern char core_pattern[];
  71 extern int pid_max;
  72 extern int min_free_kbytes;
  73 extern int printk_ratelimit_jiffies;
  74 extern int printk_ratelimit_burst;
  75 extern int pid_max_min, pid_max_max;
  76 extern int sysctl_drop_caches;
  77 extern int percpu_pagelist_fraction;
  78 extern int compat_log;
  79 extern int maps_protect;
  80 extern int sysctl_stat_interval;
  81 extern int audit_argv_kb;
  82
  83 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  84 static int maxolduid = 65535;
  85 static int minolduid;
  86 static int min_percpu_pagelist_fract = 8;
  87
  88 static int ngroups_max = NGROUPS_MAX;
  89
  90 #ifdef CONFIG_KMOD
  91 extern char modprobe_path[];
  92 #endif
  93 #ifdef CONFIG_CHR_DEV_SG
  94 extern int sg_big_buff;
  95 #endif
  96
  97 #ifdef __sparc__
  98 extern char reboot_command [];
  99 extern int stop_a_enabled;
 100 extern int scons_pwroff;
 101 #endif
 102
 103 #ifdef __hppa__
 104 extern int pwrsw_enabled;
 105 extern int unaligned_enabled;
 106 #endif
 107
 108 #ifdef CONFIG_S390
 109 #ifdef CONFIG_MATHEMU
 110 extern int sysctl_ieee_emulation_warnings;
 111 #endif
 112 extern int sysctl_userprocess_debug;
 113 extern int spin_retry;
 114 #endif
 115
 116 extern int sysctl_hz_timer;
 117
 118 #ifdef CONFIG_BSD_PROCESS_ACCT
 119 extern int acct_parm[];
 120 #endif
 121
 122 #ifdef CONFIG_IA64
 123 extern int no_unaligned_warning;
 124 #endif
 125
 126 #ifdef CONFIG_RT_MUTEXES
 127 extern int max_lock_depth;
 128 #endif
 129
 130 #ifdef CONFIG_SYSCTL_SYSCALL
 131 static int parse_table(int __user *, int, void __user *, size_t __user *,
 132                 void __user *, size_t, ctl_table *);
 133 #endif
 134
 135
 136 #ifdef CONFIG_PROC_SYSCTL
 137 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 138                   void __user *buffer, size_t *lenp, loff_t *ppos);
 139 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 140                                void __user *buffer, size_t *lenp, loff_t *ppos);
 141 #endif
 142
 143 static ctl_table root_table[];
 144 static struct ctl_table_header root_table_header =
 145         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 146
 147 static ctl_table kern_table[];
 148 static ctl_table vm_table[];
 149 static ctl_table fs_table[];
 150 static ctl_table debug_table[];
 151 static ctl_table dev_table[];
 152 extern ctl_table random_table[];
 153 #ifdef CONFIG_UNIX98_PTYS
 154 extern ctl_table pty_table[];
 155 #endif
 156 #ifdef CONFIG_INOTIFY_USER
 157 extern ctl_table inotify_table[];
 158 #endif
 159
 160 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 161 int sysctl_legacy_va_layout;
 162 #endif
 163
 164
 165 /* The default sysctl tables: */
 166
 167 static ctl_table root_table[] = {
 168         {
 169                 .ctl_name       = CTL_KERN,
 170                 .procname       = "kernel",
 171                 .mode           = 0555,
 172                 .child          = kern_table,
 173         },
 174         {
 175                 .ctl_name       = CTL_VM,
 176                 .procname       = "vm",
 177                 .mode           = 0555,
 178                 .child          = vm_table,
 179         },
 180 #ifdef CONFIG_NET
 181         {
 182                 .ctl_name       = CTL_NET,
 183                 .procname       = "net",
 184                 .mode           = 0555,
 185                 .child          = net_table,
 186         },
 187 #endif
 188         {
 189                 .ctl_name       = CTL_FS,
 190                 .procname       = "fs",
 191                 .mode           = 0555,
 192                 .child          = fs_table,
 193         },
 194         {
 195                 .ctl_name       = CTL_DEBUG,
 196                 .procname       = "debug",
 197                 .mode           = 0555,
 198                 .child          = debug_table,
 199         },
 200         {
 201                 .ctl_name       = CTL_DEV,
 202                 .procname       = "dev",
 203                 .mode           = 0555,
 204                 .child          = dev_table,
 205         },
 206 /*
 207  * NOTE: do not add new entries to this table unless you have read
 208  * Documentation/sysctl/ctl_unnumbered.txt
 209  */
 210         { .ctl_name = 0 }
 211 };
 212
 213 #ifdef CONFIG_SCHED_DEBUG
 214 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 215 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 216 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 217 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 218 #endif
 219
 220 static ctl_table kern_table[] = {
 221 #ifdef CONFIG_SCHED_DEBUG
 222         {
 223                 .ctl_name       = CTL_UNNUMBERED,
 224                 .procname       = "sched_granularity_ns",
 225                 .data           = &sysctl_sched_granularity,
 226                 .maxlen         = sizeof(unsigned int),
 227                 .mode           = 0644,
 228                 .proc_handler   = &proc_dointvec_minmax,
 229                 .strategy       = &sysctl_intvec,
 230                 .extra1         = &min_sched_granularity_ns,
 231                 .extra2         = &max_sched_granularity_ns,
 232         },
 233         {
 234                 .ctl_name       = CTL_UNNUMBERED,
 235                 .procname       = "sched_wakeup_granularity_ns",
 236                 .data           = &sysctl_sched_wakeup_granularity,
 237                 .maxlen         = sizeof(unsigned int),
 238                 .mode           = 0644,
 239                 .proc_handler   = &proc_dointvec_minmax,
 240                 .strategy       = &sysctl_intvec,
 241                 .extra1         = &min_wakeup_granularity_ns,
 242                 .extra2         = &max_wakeup_granularity_ns,
 243         },
 244         {
 245                 .ctl_name       = CTL_UNNUMBERED,
 246                 .procname       = "sched_batch_wakeup_granularity_ns",
 247                 .data           = &sysctl_sched_batch_wakeup_granularity,
 248                 .maxlen         = sizeof(unsigned int),
 249                 .mode           = 0644,
 250                 .proc_handler   = &proc_dointvec_minmax,
 251                 .strategy       = &sysctl_intvec,
 252                 .extra1         = &min_wakeup_granularity_ns,
 253                 .extra2         = &max_wakeup_granularity_ns,
 254         },
 255         {
 256                 .ctl_name       = CTL_UNNUMBERED,
 257                 .procname       = "sched_stat_granularity_ns",
 258                 .data           = &sysctl_sched_stat_granularity,
 259                 .maxlen         = sizeof(unsigned int),
 260                 .mode           = 0644,
 261                 .proc_handler   = &proc_dointvec_minmax,
 262                 .strategy       = &sysctl_intvec,
 263                 .extra1         = &min_wakeup_granularity_ns,
 264                 .extra2         = &max_wakeup_granularity_ns,
 265         },
 266         {
 267                 .ctl_name       = CTL_UNNUMBERED,
 268                 .procname       = "sched_runtime_limit_ns",
 269                 .data           = &sysctl_sched_runtime_limit,
 270                 .maxlen         = sizeof(unsigned int),
 271                 .mode           = 0644,
 272                 .proc_handler   = &proc_dointvec_minmax,
 273                 .strategy       = &sysctl_intvec,
 274                 .extra1         = &min_sched_granularity_ns,
 275                 .extra2         = &max_sched_granularity_ns,
 276         },
 277         {
 278                 .ctl_name       = CTL_UNNUMBERED,
 279                 .procname       = "sched_child_runs_first",
 280                 .data           = &sysctl_sched_child_runs_first,
 281                 .maxlen         = sizeof(unsigned int),
 282                 .mode           = 0644,
 283                 .proc_handler   = &proc_dointvec,
 284         },
 285         {
 286                 .ctl_name       = CTL_UNNUMBERED,
 287                 .procname       = "sched_features",
 288                 .data           = &sysctl_sched_features,
 289                 .maxlen         = sizeof(unsigned int),
 290                 .mode           = 0644,
 291                 .proc_handler   = &proc_dointvec,
 292         },
 293 #endif
 294         {
 295                 .ctl_name       = KERN_PANIC,
 296                 .procname       = "panic",
 297                 .data           = &panic_timeout,
 298                 .maxlen         = sizeof(int),
 299                 .mode           = 0644,
 300                 .proc_handler   = &proc_dointvec,
 301         },
 302         {
 303                 .ctl_name       = KERN_CORE_USES_PID,
 304                 .procname       = "core_uses_pid",
 305                 .data           = &core_uses_pid,
 306                 .maxlen         = sizeof(int),
 307                 .mode           = 0644,
 308                 .proc_handler   = &proc_dointvec,
 309         },
 310 #ifdef CONFIG_AUDITSYSCALL
 311         {
 312                 .ctl_name       = CTL_UNNUMBERED,
 313                 .procname       = "audit_argv_kb",
 314                 .data           = &audit_argv_kb,
 315                 .maxlen         = sizeof(int),
 316                 .mode           = 0644,
 317                 .proc_handler   = &proc_dointvec,
 318         },
 319 #endif
 320         {
 321                 .ctl_name       = KERN_CORE_PATTERN,
 322                 .procname       = "core_pattern",
 323                 .data           = core_pattern,
 324                 .maxlen         = CORENAME_MAX_SIZE,
 325                 .mode           = 0644,
 326                 .proc_handler   = &proc_dostring,
 327                 .strategy       = &sysctl_string,
 328         },
 329 #ifdef CONFIG_PROC_SYSCTL
 330         {
 331                 .ctl_name       = KERN_TAINTED,
 332                 .procname       = "tainted",
 333                 .data           = &tainted,
 334                 .maxlen         = sizeof(int),
 335                 .mode           = 0644,
 336                 .proc_handler   = &proc_dointvec_taint,
 337         },
 338 #endif
 339         {
 340                 .ctl_name       = KERN_CAP_BSET,
 341                 .procname       = "cap-bound",
 342                 .data           = &cap_bset,
 343                 .maxlen         = sizeof(kernel_cap_t),
 344                 .mode           = 0600,
 345                 .proc_handler   = &proc_dointvec_bset,
 346         },
 347 #ifdef CONFIG_BLK_DEV_INITRD
 348         {
 349                 .ctl_name       = KERN_REALROOTDEV,
 350                 .procname       = "real-root-dev",
 351                 .data           = &real_root_dev,
 352                 .maxlen         = sizeof(int),
 353                 .mode           = 0644,
 354                 .proc_handler   = &proc_dointvec,
 355         },
 356 #endif
 357         {
 358                 .ctl_name       = CTL_UNNUMBERED,
 359                 .procname       = "print-fatal-signals",
 360                 .data           = &print_fatal_signals,
 361                 .maxlen         = sizeof(int),
 362                 .mode           = 0644,
 363                 .proc_handler   = &proc_dointvec,
 364         },
 365 #ifdef __sparc__
 366         {
 367                 .ctl_name       = KERN_SPARC_REBOOT,
 368                 .procname       = "reboot-cmd",
 369                 .data           = reboot_command,
 370                 .maxlen         = 256,
 371                 .mode           = 0644,
 372                 .proc_handler   = &proc_dostring,
 373                 .strategy       = &sysctl_string,
 374         },
 375         {
 376                 .ctl_name       = KERN_SPARC_STOP_A,
 377                 .procname       = "stop-a",
 378                 .data           = &stop_a_enabled,
 379                 .maxlen         = sizeof (int),
 380                 .mode           = 0644,
 381                 .proc_handler   = &proc_dointvec,
 382         },
 383         {
 384                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 385                 .procname       = "scons-poweroff",
 386                 .data           = &scons_pwroff,
 387                 .maxlen         = sizeof (int),
 388                 .mode           = 0644,
 389                 .proc_handler   = &proc_dointvec,
 390         },
 391 #endif
 392 #ifdef __hppa__
 393         {
 394                 .ctl_name       = KERN_HPPA_PWRSW,
 395                 .procname       = "soft-power",
 396                 .data           = &pwrsw_enabled,
 397                 .maxlen         = sizeof (int),
 398                 .mode           = 0644,
 399                 .proc_handler   = &proc_dointvec,
 400         },
 401         {
 402                 .ctl_name       = KERN_HPPA_UNALIGNED,
 403                 .procname       = "unaligned-trap",
 404                 .data           = &unaligned_enabled,
 405                 .maxlen         = sizeof (int),
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_dointvec,
 408         },
 409 #endif
 410         {
 411                 .ctl_name       = KERN_CTLALTDEL,
 412                 .procname       = "ctrl-alt-del",
 413                 .data           = &C_A_D,
 414                 .maxlen         = sizeof(int),
 415                 .mode           = 0644,
 416                 .proc_handler   = &proc_dointvec,
 417         },
 418         {
 419                 .ctl_name       = KERN_PRINTK,
 420                 .procname       = "printk",
 421                 .data           = &console_loglevel,
 422                 .maxlen         = 4*sizeof(int),
 423                 .mode           = 0644,
 424                 .proc_handler   = &proc_dointvec,
 425         },
 426 #ifdef CONFIG_KMOD
 427         {
 428                 .ctl_name       = KERN_MODPROBE,
 429                 .procname       = "modprobe",
 430                 .data           = &modprobe_path,
 431                 .maxlen         = KMOD_PATH_LEN,
 432                 .mode           = 0644,
 433                 .proc_handler   = &proc_dostring,
 434                 .strategy       = &sysctl_string,
 435         },
 436 #endif
 437 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 438         {
 439                 .ctl_name       = KERN_HOTPLUG,
 440                 .procname       = "hotplug",
 441                 .data           = &uevent_helper,
 442                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 443                 .mode           = 0644,
 444                 .proc_handler   = &proc_dostring,
 445                 .strategy       = &sysctl_string,
 446         },
 447 #endif
 448 #ifdef CONFIG_CHR_DEV_SG
 449         {
 450                 .ctl_name       = KERN_SG_BIG_BUFF,
 451                 .procname       = "sg-big-buff",
 452                 .data           = &sg_big_buff,
 453                 .maxlen         = sizeof (int),
 454                 .mode           = 0444,
 455                 .proc_handler   = &proc_dointvec,
 456         },
 457 #endif
 458 #ifdef CONFIG_BSD_PROCESS_ACCT
 459         {
 460                 .ctl_name       = KERN_ACCT,
 461                 .procname       = "acct",
 462                 .data           = &acct_parm,
 463                 .maxlen         = 3*sizeof(int),
 464                 .mode           = 0644,
 465                 .proc_handler   = &proc_dointvec,
 466         },
 467 #endif
 468 #ifdef CONFIG_MAGIC_SYSRQ
 469         {
 470                 .ctl_name       = KERN_SYSRQ,
 471                 .procname       = "sysrq",
 472                 .data           = &__sysrq_enabled,
 473                 .maxlen         = sizeof (int),
 474                 .mode           = 0644,
 475                 .proc_handler   = &proc_dointvec,
 476         },
 477 #endif
 478 #ifdef CONFIG_PROC_SYSCTL
 479         {
 480                 .ctl_name       = KERN_CADPID,
 481                 .procname       = "cad_pid",
 482                 .data           = NULL,
 483                 .maxlen         = sizeof (int),
 484                 .mode           = 0600,
 485                 .proc_handler   = &proc_do_cad_pid,
 486         },
 487 #endif
 488         {
 489                 .ctl_name       = KERN_MAX_THREADS,
 490                 .procname       = "threads-max",
 491                 .data           = &max_threads,
 492                 .maxlen         = sizeof(int),
 493                 .mode           = 0644,
 494                 .proc_handler   = &proc_dointvec,
 495         },
 496         {
 497                 .ctl_name       = KERN_RANDOM,
 498                 .procname       = "random",
 499                 .mode           = 0555,
 500                 .child          = random_table,
 501         },
 502 #ifdef CONFIG_UNIX98_PTYS
 503         {
 504                 .ctl_name       = KERN_PTY,
 505                 .procname       = "pty",
 506                 .mode           = 0555,
 507                 .child          = pty_table,
 508         },
 509 #endif
 510         {
 511                 .ctl_name       = KERN_OVERFLOWUID,
 512                 .procname       = "overflowuid",
 513                 .data           = &overflowuid,
 514                 .maxlen         = sizeof(int),
 515                 .mode           = 0644,
 516                 .proc_handler   = &proc_dointvec_minmax,
 517                 .strategy       = &sysctl_intvec,
 518                 .extra1         = &minolduid,
 519                 .extra2         = &maxolduid,
 520         },
 521         {
 522                 .ctl_name       = KERN_OVERFLOWGID,
 523                 .procname       = "overflowgid",
 524                 .data           = &overflowgid,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = &proc_dointvec_minmax,
 528                 .strategy       = &sysctl_intvec,
 529                 .extra1         = &minolduid,
 530                 .extra2         = &maxolduid,
 531         },
 532 #ifdef CONFIG_S390
 533 #ifdef CONFIG_MATHEMU
 534         {
 535                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 536                 .procname       = "ieee_emulation_warnings",
 537                 .data           = &sysctl_ieee_emulation_warnings,
 538                 .maxlen         = sizeof(int),
 539                 .mode           = 0644,
 540                 .proc_handler   = &proc_dointvec,
 541         },
 542 #endif
 543 #ifdef CONFIG_NO_IDLE_HZ
 544         {
 545                 .ctl_name       = KERN_HZ_TIMER,
 546                 .procname       = "hz_timer",
 547                 .data           = &sysctl_hz_timer,
 548                 .maxlen         = sizeof(int),
 549                 .mode           = 0644,
 550                 .proc_handler   = &proc_dointvec,
 551         },
 552 #endif
 553         {
 554                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 555                 .procname       = "userprocess_debug",
 556                 .data           = &sysctl_userprocess_debug,
 557                 .maxlen         = sizeof(int),
 558                 .mode           = 0644,
 559                 .proc_handler   = &proc_dointvec,
 560         },
 561 #endif
 562         {
 563                 .ctl_name       = KERN_PIDMAX,
 564                 .procname       = "pid_max",
 565                 .data           = &pid_max,
 566                 .maxlen         = sizeof (int),
 567                 .mode           = 0644,
 568                 .proc_handler   = &proc_dointvec_minmax,
 569                 .strategy       = sysctl_intvec,
 570                 .extra1         = &pid_max_min,
 571                 .extra2         = &pid_max_max,
 572         },
 573         {
 574                 .ctl_name       = KERN_PANIC_ON_OOPS,
 575                 .procname       = "panic_on_oops",
 576                 .data           = &panic_on_oops,
 577                 .maxlen         = sizeof(int),
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dointvec,
 580         },
 581         {
 582                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 583                 .procname       = "printk_ratelimit",
 584                 .data           = &printk_ratelimit_jiffies,
 585                 .maxlen         = sizeof(int),
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dointvec_jiffies,
 588                 .strategy       = &sysctl_jiffies,
 589         },
 590         {
 591                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 592                 .procname       = "printk_ratelimit_burst",
 593                 .data           = &printk_ratelimit_burst,
 594                 .maxlen         = sizeof(int),
 595                 .mode           = 0644,
 596                 .proc_handler   = &proc_dointvec,
 597         },
 598         {
 599                 .ctl_name       = KERN_NGROUPS_MAX,
 600                 .procname       = "ngroups_max",
 601                 .data           = &ngroups_max,
 602                 .maxlen         = sizeof (int),
 603                 .mode           = 0444,
 604                 .proc_handler   = &proc_dointvec,
 605         },
 606 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 607         {
 608                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 609                 .procname       = "unknown_nmi_panic",
 610                 .data           = &unknown_nmi_panic,
 611                 .maxlen         = sizeof (int),
 612                 .mode           = 0644,
 613                 .proc_handler   = &proc_dointvec,
 614         },
 615         {
 616                 .ctl_name       = KERN_NMI_WATCHDOG,
 617                 .procname       = "nmi_watchdog",
 618                 .data           = &nmi_watchdog_enabled,
 619                 .maxlen         = sizeof (int),
 620                 .mode           = 0644,
 621                 .proc_handler   = &proc_nmi_enabled,
 622         },
 623 #endif
 624 #if defined(CONFIG_X86)
 625         {
 626                 .ctl_name       = KERN_PANIC_ON_NMI,
 627                 .procname       = "panic_on_unrecovered_nmi",
 628                 .data           = &panic_on_unrecovered_nmi,
 629                 .maxlen         = sizeof(int),
 630                 .mode           = 0644,
 631                 .proc_handler   = &proc_dointvec,
 632         },
 633         {
 634                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 635                 .procname       = "bootloader_type",
 636                 .data           = &bootloader_type,
 637                 .maxlen         = sizeof (int),
 638                 .mode           = 0444,
 639                 .proc_handler   = &proc_dointvec,
 640         },
 641         {
 642                 .ctl_name       = CTL_UNNUMBERED,
 643                 .procname       = "kstack_depth_to_print",
 644                 .data           = &kstack_depth_to_print,
 645                 .maxlen         = sizeof(int),
 646                 .mode           = 0644,
 647                 .proc_handler   = &proc_dointvec,
 648         },
 649 #endif
 650 #if defined(CONFIG_MMU)
 651         {
 652                 .ctl_name       = KERN_RANDOMIZE,
 653                 .procname       = "randomize_va_space",
 654                 .data           = &randomize_va_space,
 655                 .maxlen         = sizeof(int),
 656                 .mode           = 0644,
 657                 .proc_handler   = &proc_dointvec,
 658         },
 659 #endif
 660 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 661         {
 662                 .ctl_name       = KERN_SPIN_RETRY,
 663                 .procname       = "spin_retry",
 664                 .data           = &spin_retry,
 665                 .maxlen         = sizeof (int),
 666                 .mode           = 0644,
 667                 .proc_handler   = &proc_dointvec,
 668         },
 669 #endif
 670 #ifdef CONFIG_ACPI_SLEEP
 671         {
 672                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 673                 .procname       = "acpi_video_flags",
 674                 .data           = &acpi_realmode_flags,
 675                 .maxlen         = sizeof (unsigned long),
 676                 .mode           = 0644,
 677                 .proc_handler   = &proc_doulongvec_minmax,
 678         },
 679 #endif
 680 #ifdef CONFIG_IA64
 681         {
 682                 .ctl_name       = KERN_IA64_UNALIGNED,
 683                 .procname       = "ignore-unaligned-usertrap",
 684                 .data           = &no_unaligned_warning,
 685                 .maxlen         = sizeof (int),
 686                 .mode           = 0644,
 687                 .proc_handler   = &proc_dointvec,
 688         },
 689 #endif
 690 #ifdef CONFIG_COMPAT
 691         {
 692                 .ctl_name       = KERN_COMPAT_LOG,
 693                 .procname       = "compat-log",
 694                 .data           = &compat_log,
 695                 .maxlen         = sizeof (int),
 696                 .mode           = 0644,
 697                 .proc_handler   = &proc_dointvec,
 698         },
 699 #endif
 700 #ifdef CONFIG_RT_MUTEXES
 701         {
 702                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 703                 .procname       = "max_lock_depth",
 704                 .data           = &max_lock_depth,
 705                 .maxlen         = sizeof(int),
 706                 .mode           = 0644,
 707                 .proc_handler   = &proc_dointvec,
 708         },
 709 #endif
 710 #ifdef CONFIG_PROC_FS
 711         {
 712                 .ctl_name       = CTL_UNNUMBERED,
 713                 .procname       = "maps_protect",
 714                 .data           = &maps_protect,
 715                 .maxlen         = sizeof(int),
 716                 .mode           = 0644,
 717                 .proc_handler   = &proc_dointvec,
 718         },
 719 #endif
 720         {
 721                 .ctl_name       = CTL_UNNUMBERED,
 722                 .procname       = "poweroff_cmd",
 723                 .data           = &poweroff_cmd,
 724                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 725                 .mode           = 0644,
 726                 .proc_handler   = &proc_dostring,
 727                 .strategy       = &sysctl_string,
 728         },
 729
 730         { .ctl_name = 0 }
 731 };
 732
 733 /* Constants for minimum and maximum testing in vm_table.
 734    We use these as one-element integer vectors. */
 735 static int zero;
 736 static int two = 2;
 737 static int one_hundred = 100;
 738
 739
 740 static ctl_table vm_table[] = {
 741         {
 742                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 743                 .procname       = "overcommit_memory",
 744                 .data           = &sysctl_overcommit_memory,
 745                 .maxlen         = sizeof(sysctl_overcommit_memory),
 746                 .mode           = 0644,
 747                 .proc_handler   = &proc_dointvec,
 748         },
 749         {
 750                 .ctl_name       = VM_PANIC_ON_OOM,
 751                 .procname       = "panic_on_oom",
 752                 .data           = &sysctl_panic_on_oom,
 753                 .maxlen         = sizeof(sysctl_panic_on_oom),
 754                 .mode           = 0644,
 755                 .proc_handler   = &proc_dointvec,
 756         },
 757         {
 758                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 759                 .procname       = "overcommit_ratio",
 760                 .data           = &sysctl_overcommit_ratio,
 761                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 762                 .mode           = 0644,
 763                 .proc_handler   = &proc_dointvec,
 764         },
 765         {
 766                 .ctl_name       = VM_PAGE_CLUSTER,
 767                 .procname       = "page-cluster",
 768                 .data           = &page_cluster,
 769                 .maxlen         = sizeof(int),
 770                 .mode           = 0644,
 771                 .proc_handler   = &proc_dointvec,
 772         },
 773         {
 774                 .ctl_name       = VM_DIRTY_BACKGROUND,
 775                 .procname       = "dirty_background_ratio",
 776                 .data           = &dirty_background_ratio,
 777                 .maxlen         = sizeof(dirty_background_ratio),
 778                 .mode           = 0644,
 779                 .proc_handler   = &proc_dointvec_minmax,
 780                 .strategy       = &sysctl_intvec,
 781                 .extra1         = &zero,
 782                 .extra2         = &one_hundred,
 783         },
 784         {
 785                 .ctl_name       = VM_DIRTY_RATIO,
 786                 .procname       = "dirty_ratio",
 787                 .data           = &vm_dirty_ratio,
 788                 .maxlen         = sizeof(vm_dirty_ratio),
 789                 .mode           = 0644,
 790                 .proc_handler   = &proc_dointvec_minmax,
 791                 .strategy       = &sysctl_intvec,
 792                 .extra1         = &zero,
 793                 .extra2         = &one_hundred,
 794         },
 795         {
 796                 .ctl_name       = VM_DIRTY_WB_CS,
 797                 .procname       = "dirty_writeback_centisecs",
 798                 .data           = &dirty_writeback_interval,
 799                 .maxlen         = sizeof(dirty_writeback_interval),
 800                 .mode           = 0644,
 801                 .proc_handler   = &dirty_writeback_centisecs_handler,
 802         },
 803         {
 804                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 805                 .procname       = "dirty_expire_centisecs",
 806                 .data           = &dirty_expire_interval,
 807                 .maxlen         = sizeof(dirty_expire_interval),
 808                 .mode           = 0644,
 809                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 810         },
 811         {
 812                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 813                 .procname       = "nr_pdflush_threads",
 814                 .data           = &nr_pdflush_threads,
 815                 .maxlen         = sizeof nr_pdflush_threads,
 816                 .mode           = 0444 /* read-only*/,
 817                 .proc_handler   = &proc_dointvec,
 818         },
 819         {
 820                 .ctl_name       = VM_SWAPPINESS,
 821                 .procname       = "swappiness",
 822                 .data           = &vm_swappiness,
 823                 .maxlen         = sizeof(vm_swappiness),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_dointvec_minmax,
 826                 .strategy       = &sysctl_intvec,
 827                 .extra1         = &zero,
 828                 .extra2         = &one_hundred,
 829         },
 830 #ifdef CONFIG_HUGETLB_PAGE
 831          {
 832                 .ctl_name       = VM_HUGETLB_PAGES,
 833                 .procname       = "nr_hugepages",
 834                 .data           = &max_huge_pages,
 835                 .maxlen         = sizeof(unsigned long),
 836                 .mode           = 0644,
 837                 .proc_handler   = &hugetlb_sysctl_handler,
 838                 .extra1         = (void *)&hugetlb_zero,
 839                 .extra2         = (void *)&hugetlb_infinity,
 840          },
 841          {
 842                 .ctl_name       = VM_HUGETLB_GROUP,
 843                 .procname       = "hugetlb_shm_group",
 844                 .data           = &sysctl_hugetlb_shm_group,
 845                 .maxlen         = sizeof(gid_t),
 846                 .mode           = 0644,
 847                 .proc_handler   = &proc_dointvec,
 848          },
 849          {
 850                 .ctl_name       = CTL_UNNUMBERED,
 851                 .procname       = "hugepages_treat_as_movable",
 852                 .data           = &hugepages_treat_as_movable,
 853                 .maxlen         = sizeof(int),
 854                 .mode           = 0644,
 855                 .proc_handler   = &hugetlb_treat_movable_handler,
 856         },
 857 #endif
 858         {
 859                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 860                 .procname       = "lowmem_reserve_ratio",
 861                 .data           = &sysctl_lowmem_reserve_ratio,
 862                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 863                 .mode           = 0644,
 864                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 865                 .strategy       = &sysctl_intvec,
 866         },
 867         {
 868                 .ctl_name       = VM_DROP_PAGECACHE,
 869                 .procname       = "drop_caches",
 870                 .data           = &sysctl_drop_caches,
 871                 .maxlen         = sizeof(int),
 872                 .mode           = 0644,
 873                 .proc_handler   = drop_caches_sysctl_handler,
 874                 .strategy       = &sysctl_intvec,
 875         },
 876         {
 877                 .ctl_name       = VM_MIN_FREE_KBYTES,
 878                 .procname       = "min_free_kbytes",
 879                 .data           = &min_free_kbytes,
 880                 .maxlen         = sizeof(min_free_kbytes),
 881                 .mode           = 0644,
 882                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 883                 .strategy       = &sysctl_intvec,
 884                 .extra1         = &zero,
 885         },
 886         {
 887                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 888                 .procname       = "percpu_pagelist_fraction",
 889                 .data           = &percpu_pagelist_fraction,
 890                 .maxlen         = sizeof(percpu_pagelist_fraction),
 891                 .mode           = 0644,
 892                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 893                 .strategy       = &sysctl_intvec,
 894                 .extra1         = &min_percpu_pagelist_fract,
 895         },
 896 #ifdef CONFIG_MMU
 897         {
 898                 .ctl_name       = VM_MAX_MAP_COUNT,
 899                 .procname       = "max_map_count",
 900                 .data           = &sysctl_max_map_count,
 901                 .maxlen         = sizeof(sysctl_max_map_count),
 902                 .mode           = 0644,
 903                 .proc_handler   = &proc_dointvec
 904         },
 905 #endif
 906         {
 907                 .ctl_name       = VM_LAPTOP_MODE,
 908                 .procname       = "laptop_mode",
 909                 .data           = &laptop_mode,
 910                 .maxlen         = sizeof(laptop_mode),
 911                 .mode           = 0644,
 912                 .proc_handler   = &proc_dointvec_jiffies,
 913                 .strategy       = &sysctl_jiffies,
 914         },
 915         {
 916                 .ctl_name       = VM_BLOCK_DUMP,
 917                 .procname       = "block_dump",
 918                 .data           = &block_dump,
 919                 .maxlen         = sizeof(block_dump),
 920                 .mode           = 0644,
 921                 .proc_handler   = &proc_dointvec,
 922                 .strategy       = &sysctl_intvec,
 923                 .extra1         = &zero,
 924         },
 925         {
 926                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 927                 .procname       = "vfs_cache_pressure",
 928                 .data           = &sysctl_vfs_cache_pressure,
 929                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 930                 .mode           = 0644,
 931                 .proc_handler   = &proc_dointvec,
 932                 .strategy       = &sysctl_intvec,
 933                 .extra1         = &zero,
 934         },
 935 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 936         {
 937                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 938                 .procname       = "legacy_va_layout",
 939                 .data           = &sysctl_legacy_va_layout,
 940                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 941                 .mode           = 0644,
 942                 .proc_handler   = &proc_dointvec,
 943                 .strategy       = &sysctl_intvec,
 944                 .extra1         = &zero,
 945         },
 946 #endif
 947 #ifdef CONFIG_NUMA
 948         {
 949                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 950                 .procname       = "zone_reclaim_mode",
 951                 .data           = &zone_reclaim_mode,
 952                 .maxlen         = sizeof(zone_reclaim_mode),
 953                 .mode           = 0644,
 954                 .proc_handler   = &proc_dointvec,
 955                 .strategy       = &sysctl_intvec,
 956                 .extra1         = &zero,
 957         },
 958         {
 959                 .ctl_name       = VM_MIN_UNMAPPED,
 960                 .procname       = "min_unmapped_ratio",
 961                 .data           = &sysctl_min_unmapped_ratio,
 962                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 963                 .mode           = 0644,
 964                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 965                 .strategy       = &sysctl_intvec,
 966                 .extra1         = &zero,
 967                 .extra2         = &one_hundred,
 968         },
 969         {
 970                 .ctl_name       = VM_MIN_SLAB,
 971                 .procname       = "min_slab_ratio",
 972                 .data           = &sysctl_min_slab_ratio,
 973                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 974                 .mode           = 0644,
 975                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 976                 .strategy       = &sysctl_intvec,
 977                 .extra1         = &zero,
 978                 .extra2         = &one_hundred,
 979         },
 980 #endif
 981 #ifdef CONFIG_SMP
 982         {
 983                 .ctl_name       = CTL_UNNUMBERED,
 984                 .procname       = "stat_interval",
 985                 .data           = &sysctl_stat_interval,
 986                 .maxlen         = sizeof(sysctl_stat_interval),
 987                 .mode           = 0644,
 988                 .proc_handler   = &proc_dointvec_jiffies,
 989                 .strategy       = &sysctl_jiffies,
 990         },
 991 #endif
 992 #ifdef CONFIG_SECURITY
 993         {
 994                 .ctl_name       = CTL_UNNUMBERED,
 995                 .procname       = "mmap_min_addr",
 996                 .data           = &mmap_min_addr,
 997                 .maxlen         = sizeof(unsigned long),
 998                 .mode           = 0644,
 999                 .proc_handler   = &proc_doulongvec_minmax,
1000         },
1001 #ifdef CONFIG_NUMA
1002         {
1003                 .ctl_name       = CTL_UNNUMBERED,
1004                 .procname       = "numa_zonelist_order",
1005                 .data           = &numa_zonelist_order,
1006                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1007                 .mode           = 0644,
1008                 .proc_handler   = &numa_zonelist_order_handler,
1009                 .strategy       = &sysctl_string,
1010         },
1011 #endif
1012 #endif
1013 #if defined(CONFIG_X86_32) || \
1014    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1015         {
1016                 .ctl_name       = VM_VDSO_ENABLED,
1017                 .procname       = "vdso_enabled",
1018                 .data           = &vdso_enabled,
1019                 .maxlen         = sizeof(vdso_enabled),
1020                 .mode           = 0644,
1021                 .proc_handler   = &proc_dointvec,
1022                 .strategy       = &sysctl_intvec,
1023                 .extra1         = &zero,
1024         },
1025 #endif
1026 /*
1027  * NOTE: do not add new entries to this table unless you have read
1028  * Documentation/sysctl/ctl_unnumbered.txt
1029  */
1030         { .ctl_name = 0 }
1031 };
1032
1033 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1034 static ctl_table binfmt_misc_table[] = {
1035         { .ctl_name = 0 }
1036 };
1037 #endif
1038
1039 static ctl_table fs_table[] = {
1040         {
1041                 .ctl_name       = FS_NRINODE,
1042                 .procname       = "inode-nr",
1043                 .data           = &inodes_stat,
1044                 .maxlen         = 2*sizeof(int),
1045                 .mode           = 0444,
1046                 .proc_handler   = &proc_dointvec,
1047         },
1048         {
1049                 .ctl_name       = FS_STATINODE,
1050                 .procname       = "inode-state",
1051                 .data           = &inodes_stat,
1052                 .maxlen         = 7*sizeof(int),
1053                 .mode           = 0444,
1054                 .proc_handler   = &proc_dointvec,
1055         },
1056         {
1057                 .ctl_name       = FS_NRFILE,
1058                 .procname       = "file-nr",
1059                 .data           = &files_stat,
1060                 .maxlen         = 3*sizeof(int),
1061                 .mode           = 0444,
1062                 .proc_handler   = &proc_nr_files,
1063         },
1064         {
1065                 .ctl_name       = FS_MAXFILE,
1066                 .procname       = "file-max",
1067                 .data           = &files_stat.max_files,
1068                 .maxlen         = sizeof(int),
1069                 .mode           = 0644,
1070                 .proc_handler   = &proc_dointvec,
1071         },
1072         {
1073                 .ctl_name       = FS_DENTRY,
1074                 .procname       = "dentry-state",
1075                 .data           = &dentry_stat,
1076                 .maxlen         = 6*sizeof(int),
1077                 .mode           = 0444,
1078                 .proc_handler   = &proc_dointvec,
1079         },
1080         {
1081                 .ctl_name       = FS_OVERFLOWUID,
1082                 .procname       = "overflowuid",
1083                 .data           = &fs_overflowuid,
1084                 .maxlen         = sizeof(int),
1085                 .mode           = 0644,
1086                 .proc_handler   = &proc_dointvec_minmax,
1087                 .strategy       = &sysctl_intvec,
1088                 .extra1         = &minolduid,
1089                 .extra2         = &maxolduid,
1090         },
1091         {
1092                 .ctl_name       = FS_OVERFLOWGID,
1093                 .procname       = "overflowgid",
1094                 .data           = &fs_overflowgid,
1095                 .maxlen         = sizeof(int),
1096                 .mode           = 0644,
1097                 .proc_handler   = &proc_dointvec_minmax,
1098                 .strategy       = &sysctl_intvec,
1099                 .extra1         = &minolduid,
1100                 .extra2         = &maxolduid,
1101         },
1102         {
1103                 .ctl_name       = FS_LEASES,
1104                 .procname       = "leases-enable",
1105                 .data           = &leases_enable,
1106                 .maxlen         = sizeof(int),
1107                 .mode           = 0644,
1108                 .proc_handler   = &proc_dointvec,
1109         },
1110 #ifdef CONFIG_DNOTIFY
1111         {
1112                 .ctl_name       = FS_DIR_NOTIFY,
1113                 .procname       = "dir-notify-enable",
1114                 .data           = &dir_notify_enable,
1115                 .maxlen         = sizeof(int),
1116                 .mode           = 0644,
1117                 .proc_handler   = &proc_dointvec,
1118         },
1119 #endif
1120 #ifdef CONFIG_MMU
1121         {
1122                 .ctl_name       = FS_LEASE_TIME,
1123                 .procname       = "lease-break-time",
1124                 .data           = &lease_break_time,
1125                 .maxlen         = sizeof(int),
1126                 .mode           = 0644,
1127                 .proc_handler   = &proc_dointvec_minmax,
1128                 .strategy       = &sysctl_intvec,
1129                 .extra1         = &zero,
1130                 .extra2         = &two,
1131         },
1132         {
1133                 .ctl_name       = FS_AIO_NR,
1134                 .procname       = "aio-nr",
1135                 .data           = &aio_nr,
1136                 .maxlen         = sizeof(aio_nr),
1137                 .mode           = 0444,
1138                 .proc_handler   = &proc_doulongvec_minmax,
1139         },
1140         {
1141                 .ctl_name       = FS_AIO_MAX_NR,
1142                 .procname       = "aio-max-nr",
1143                 .data           = &aio_max_nr,
1144                 .maxlen         = sizeof(aio_max_nr),
1145                 .mode           = 0644,
1146                 .proc_handler   = &proc_doulongvec_minmax,
1147         },
1148 #ifdef CONFIG_INOTIFY_USER
1149         {
1150                 .ctl_name       = FS_INOTIFY,
1151                 .procname       = "inotify",
1152                 .mode           = 0555,
1153                 .child          = inotify_table,
1154         },
1155 #endif
1156 #endif
1157         {
1158                 .ctl_name       = KERN_SETUID_DUMPABLE,
1159                 .procname       = "suid_dumpable",
1160                 .data           = &suid_dumpable,
1161                 .maxlen         = sizeof(int),
1162                 .mode           = 0644,
1163                 .proc_handler   = &proc_dointvec,
1164         },
1165 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1166         {
1167                 .ctl_name       = CTL_UNNUMBERED,
1168                 .procname       = "binfmt_misc",
1169                 .mode           = 0555,
1170                 .child          = binfmt_misc_table,
1171         },
1172 #endif
1173 /*
1174  * NOTE: do not add new entries to this table unless you have read
1175  * Documentation/sysctl/ctl_unnumbered.txt
1176  */
1177         { .ctl_name = 0 }
1178 };
1179
1180 static ctl_table debug_table[] = {
1181         { .ctl_name = 0 }
1182 };
1183
1184 static ctl_table dev_table[] = {
1185         { .ctl_name = 0 }
1186 };
1187
1188 static DEFINE_SPINLOCK(sysctl_lock);
1189
1190 /* called under sysctl_lock */
1191 static int use_table(struct ctl_table_header *p)
1192 {
1193         if (unlikely(p->unregistering))
1194                 return 0;
1195         p->used++;
1196         return 1;
1197 }
1198
1199 /* called under sysctl_lock */
1200 static void unuse_table(struct ctl_table_header *p)
1201 {
1202         if (!--p->used)
1203                 if (unlikely(p->unregistering))
1204                         complete(p->unregistering);
1205 }
1206
1207 /* called under sysctl_lock, will reacquire if has to wait */
1208 static void start_unregistering(struct ctl_table_header *p)
1209 {
1210         /*
1211          * if p->used is 0, nobody will ever touch that entry again;
1212          * we'll eliminate all paths to it before dropping sysctl_lock
1213          */
1214         if (unlikely(p->used)) {
1215                 struct completion wait;
1216                 init_completion(&wait);
1217                 p->unregistering = &wait;
1218                 spin_unlock(&sysctl_lock);
1219                 wait_for_completion(&wait);
1220                 spin_lock(&sysctl_lock);
1221         }
1222         /*
1223          * do not remove from the list until nobody holds it; walking the
1224          * list in do_sysctl() relies on that.
1225          */
1226         list_del_init(&p->ctl_entry);
1227 }
1228
1229 void sysctl_head_finish(struct ctl_table_header *head)
1230 {
1231         if (!head)
1232                 return;
1233         spin_lock(&sysctl_lock);
1234         unuse_table(head);
1235         spin_unlock(&sysctl_lock);
1236 }
1237
1238 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1239 {
1240         struct ctl_table_header *head;
1241         struct list_head *tmp;
1242         spin_lock(&sysctl_lock);
1243         if (prev) {
1244                 tmp = &prev->ctl_entry;
1245                 unuse_table(prev);
1246                 goto next;
1247         }
1248         tmp = &root_table_header.ctl_entry;
1249         for (;;) {
1250                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1251
1252                 if (!use_table(head))
1253                         goto next;
1254                 spin_unlock(&sysctl_lock);
1255                 return head;
1256         next:
1257                 tmp = tmp->next;
1258                 if (tmp == &root_table_header.ctl_entry)
1259                         break;
1260         }
1261         spin_unlock(&sysctl_lock);
1262         return NULL;
1263 }
1264
1265 #ifdef CONFIG_SYSCTL_SYSCALL
1266 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1267                void __user *newval, size_t newlen)
1268 {
1269         struct ctl_table_header *head;
1270         int error = -ENOTDIR;
1271
1272         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1273                 return -ENOTDIR;
1274         if (oldval) {
1275                 int old_len;
1276                 if (!oldlenp || get_user(old_len, oldlenp))
1277                         return -EFAULT;
1278         }
1279
1280         for (head = sysctl_head_next(NULL); head;
1281                         head = sysctl_head_next(head)) {
1282                 error = parse_table(name, nlen, oldval, oldlenp,
1283                                         newval, newlen, head->ctl_table);
1284                 if (error != -ENOTDIR) {
1285                         sysctl_head_finish(head);
1286                         break;
1287                 }
1288         }
1289         return error;
1290 }
1291
1292 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1293 {
1294         struct __sysctl_args tmp;
1295         int error;
1296
1297         if (copy_from_user(&tmp, args, sizeof(tmp)))
1298                 return -EFAULT;
1299
1300         lock_kernel();
1301         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1302                           tmp.newval, tmp.newlen);
1303         unlock_kernel();
1304         return error;
1305 }
1306 #endif /* CONFIG_SYSCTL_SYSCALL */
1307
1308 /*
1309  * sysctl_perm does NOT grant the superuser all rights automatically, because
1310  * some sysctl variables are readonly even to root.
1311  */
1312
1313 static int test_perm(int mode, int op)
1314 {
1315         if (!current->euid)
1316                 mode >>= 6;
1317         else if (in_egroup_p(0))
1318                 mode >>= 3;
1319         if ((mode & op & 0007) == op)
1320                 return 0;
1321         return -EACCES;
1322 }
1323
1324 int sysctl_perm(ctl_table *table, int op)
1325 {
1326         int error;
1327         error = security_sysctl(table, op);
1328         if (error)
1329                 return error;
1330         return test_perm(table->mode, op);
1331 }
1332
1333 #ifdef CONFIG_SYSCTL_SYSCALL
1334 static int parse_table(int __user *name, int nlen,
1335                        void __user *oldval, size_t __user *oldlenp,
1336                        void __user *newval, size_t newlen,
1337                        ctl_table *table)
1338 {
1339         int n;
1340 repeat:
1341         if (!nlen)
1342                 return -ENOTDIR;
1343         if (get_user(n, name))
1344                 return -EFAULT;
1345         for ( ; table->ctl_name || table->procname; table++) {
1346                 if (!table->ctl_name)
1347                         continue;
1348                 if (n == table->ctl_name) {
1349                         int error;
1350                         if (table->child) {
1351                                 if (sysctl_perm(table, 001))
1352                                         return -EPERM;
1353                                 name++;
1354                                 nlen--;
1355                                 table = table->child;
1356                                 goto repeat;
1357                         }
1358                         error = do_sysctl_strategy(table, name, nlen,
1359                                                    oldval, oldlenp,
1360                                                    newval, newlen);
1361                         return error;
1362                 }
1363         }
1364         return -ENOTDIR;
1365 }
1366
1367 /* Perform the actual read/write of a sysctl table entry. */
1368 int do_sysctl_strategy (ctl_table *table,
1369                         int __user *name, int nlen,
1370                         void __user *oldval, size_t __user *oldlenp,
1371                         void __user *newval, size_t newlen)
1372 {
1373         int op = 0, rc;
1374         size_t len;
1375
1376         if (oldval)
1377                 op |= 004;
1378         if (newval)
1379                 op |= 002;
1380         if (sysctl_perm(table, op))
1381                 return -EPERM;
1382
1383         if (table->strategy) {
1384                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1385                                      newval, newlen);
1386                 if (rc < 0)
1387                         return rc;
1388                 if (rc > 0)
1389                         return 0;
1390         }
1391
1392         /* If there is no strategy routine, or if the strategy returns
1393          * zero, proceed with automatic r/w */
1394         if (table->data && table->maxlen) {
1395                 if (oldval && oldlenp) {
1396                         if (get_user(len, oldlenp))
1397                                 return -EFAULT;
1398                         if (len) {
1399                                 if (len > table->maxlen)
1400                                         len = table->maxlen;
1401                                 if(copy_to_user(oldval, table->data, len))
1402                                         return -EFAULT;
1403                                 if(put_user(len, oldlenp))
1404                                         return -EFAULT;
1405                         }
1406                 }
1407                 if (newval && newlen) {
1408                         len = newlen;
1409                         if (len > table->maxlen)
1410                                 len = table->maxlen;
1411                         if(copy_from_user(table->data, newval, len))
1412                                 return -EFAULT;
1413                 }
1414         }
1415         return 0;
1416 }
1417 #endif /* CONFIG_SYSCTL_SYSCALL */
1418
1419 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1420 {
1421         for (; table->ctl_name || table->procname; table++) {
1422                 table->parent = parent;
1423                 if (table->child)
1424                         sysctl_set_parent(table, table->child);
1425         }
1426 }
1427
1428 static __init int sysctl_init(void)
1429 {
1430         sysctl_set_parent(NULL, root_table);
1431         return 0;
1432 }
1433
1434 core_initcall(sysctl_init);
1435
1436 /**
1437  * register_sysctl_table - register a sysctl hierarchy
1438  * @table: the top-level table structure
1439  *
1440  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1441  * array. An entry with a ctl_name of 0 terminates the table.
1442  *
1443  * The members of the &ctl_table structure are used as follows:
1444  *
1445  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1446  *            must be unique within that level of sysctl
1447  *
1448  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1449  *            enter a sysctl file
1450  *
1451  * data - a pointer to data for use by proc_handler
1452  *
1453  * maxlen - the maximum size in bytes of the data
1454  *
1455  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1456  *
1457  * child - a pointer to the child sysctl table if this entry is a directory, or
1458  *         %NULL.
1459  *
1460  * proc_handler - the text handler routine (described below)
1461  *
1462  * strategy - the strategy routine (described below)
1463  *
1464  * de - for internal use by the sysctl routines
1465  *
1466  * extra1, extra2 - extra pointers usable by the proc handler routines
1467  *
1468  * Leaf nodes in the sysctl tree will be represented by a single file
1469  * under /proc; non-leaf nodes will be represented by directories.
1470  *
1471  * sysctl(2) can automatically manage read and write requests through
1472  * the sysctl table.  The data and maxlen fields of the ctl_table
1473  * struct enable minimal validation of the values being written to be
1474  * performed, and the mode field allows minimal authentication.
1475  *
1476  * More sophisticated management can be enabled by the provision of a
1477  * strategy routine with the table entry.  This will be called before
1478  * any automatic read or write of the data is performed.
1479  *
1480  * The strategy routine may return
1481  *
1482  * < 0 - Error occurred (error is passed to user process)
1483  *
1484  * 0   - OK - proceed with automatic read or write.
1485  *
1486  * > 0 - OK - read or write has been done by the strategy routine, so
1487  *       return immediately.
1488  *
1489  * There must be a proc_handler routine for any terminal nodes
1490  * mirrored under /proc/sys (non-terminals are handled by a built-in
1491  * directory handler).  Several default handlers are available to
1492  * cover common cases -
1493  *
1494  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1495  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1496  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1497  *
1498  * It is the handler's job to read the input buffer from user memory
1499  * and process it. The handler should return 0 on success.
1500  *
1501  * This routine returns %NULL on a failure to register, and a pointer
1502  * to the table header on success.
1503  */
1504 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1505 {
1506         struct ctl_table_header *tmp;
1507         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1508         if (!tmp)
1509                 return NULL;
1510         tmp->ctl_table = table;
1511         INIT_LIST_HEAD(&tmp->ctl_entry);
1512         tmp->used = 0;
1513         tmp->unregistering = NULL;
1514         sysctl_set_parent(NULL, table);
1515         spin_lock(&sysctl_lock);
1516         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1517         spin_unlock(&sysctl_lock);
1518         return tmp;
1519 }
1520
1521 /**
1522  * unregister_sysctl_table - unregister a sysctl table hierarchy
1523  * @header: the header returned from register_sysctl_table
1524  *
1525  * Unregisters the sysctl table and all children. proc entries may not
1526  * actually be removed until they are no longer used by anyone.
1527  */
1528 void unregister_sysctl_table(struct ctl_table_header * header)
1529 {
1530         might_sleep();
1531         spin_lock(&sysctl_lock);
1532         start_unregistering(header);
1533         spin_unlock(&sysctl_lock);
1534         kfree(header);
1535 }
1536
1537 #else /* !CONFIG_SYSCTL */
1538 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1539 {
1540         return NULL;
1541 }
1542
1543 void unregister_sysctl_table(struct ctl_table_header * table)
1544 {
1545 }
1546
1547 #endif /* CONFIG_SYSCTL */
1548
1549 /*
1550  * /proc/sys support
1551  */
1552
1553 #ifdef CONFIG_PROC_SYSCTL
1554
1555 static int _proc_do_string(void* data, int maxlen, int write,
1556                            struct file *filp, void __user *buffer,
1557                            size_t *lenp, loff_t *ppos)
1558 {
1559         size_t len;
1560         char __user *p;
1561         char c;
1562
1563         if (!data || !maxlen || !*lenp) {
1564                 *lenp = 0;
1565                 return 0;
1566         }
1567
1568         if (write) {
1569                 len = 0;
1570                 p = buffer;
1571                 while (len < *lenp) {
1572                         if (get_user(c, p++))
1573                                 return -EFAULT;
1574                         if (c == 0 || c == '\n')
1575                                 break;
1576                         len++;
1577                 }
1578                 if (len >= maxlen)
1579                         len = maxlen-1;
1580                 if(copy_from_user(data, buffer, len))
1581                         return -EFAULT;
1582                 ((char *) data)[len] = 0;
1583                 *ppos += *lenp;
1584         } else {
1585                 len = strlen(data);
1586                 if (len > maxlen)
1587                         len = maxlen;
1588
1589                 if (*ppos > len) {
1590                         *lenp = 0;
1591                         return 0;
1592                 }
1593
1594                 data += *ppos;
1595                 len  -= *ppos;
1596
1597                 if (len > *lenp)
1598                         len = *lenp;
1599                 if (len)
1600                         if(copy_to_user(buffer, data, len))
1601                                 return -EFAULT;
1602                 if (len < *lenp) {
1603                         if(put_user('\n', ((char __user *) buffer) + len))
1604                                 return -EFAULT;
1605                         len++;
1606                 }
1607                 *lenp = len;
1608                 *ppos += len;
1609         }
1610         return 0;
1611 }
1612
1613 /**
1614  * proc_dostring - read a string sysctl
1615  * @table: the sysctl table
1616  * @write: %TRUE if this is a write to the sysctl file
1617  * @filp: the file structure
1618  * @buffer: the user buffer
1619  * @lenp: the size of the user buffer
1620  * @ppos: file position
1621  *
1622  * Reads/writes a string from/to the user buffer. If the kernel
1623  * buffer provided is not large enough to hold the string, the
1624  * string is truncated. The copied string is %NULL-terminated.
1625  * If the string is being read by the user process, it is copied
1626  * and a newline '\n' is added. It is truncated if the buffer is
1627  * not large enough.
1628  *
1629  * Returns 0 on success.
1630  */
1631 int proc_dostring(ctl_table *table, int write, struct file *filp,
1632                   void __user *buffer, size_t *lenp, loff_t *ppos)
1633 {
1634         return _proc_do_string(table->data, table->maxlen, write, filp,
1635                                buffer, lenp, ppos);
1636 }
1637
1638
1639 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1640                                  int *valp,
1641                                  int write, void *data)
1642 {
1643         if (write) {
1644                 *valp = *negp ? -*lvalp : *lvalp;
1645         } else {
1646                 int val = *valp;
1647                 if (val < 0) {
1648                         *negp = -1;
1649                         *lvalp = (unsigned long)-val;
1650                 } else {
1651                         *negp = 0;
1652                         *lvalp = (unsigned long)val;
1653                 }
1654         }
1655         return 0;
1656 }
1657
1658 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1659                   int write, struct file *filp, void __user *buffer,
1660                   size_t *lenp, loff_t *ppos,
1661                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1662                               int write, void *data),
1663                   void *data)
1664 {
1665 #define TMPBUFLEN 21
1666         int *i, vleft, first=1, neg, val;
1667         unsigned long lval;
1668         size_t left, len;
1669
1670         char buf[TMPBUFLEN], *p;
1671         char __user *s = buffer;
1672
1673         if (!tbl_data || !table->maxlen || !*lenp ||
1674             (*ppos && !write)) {
1675                 *lenp = 0;
1676                 return 0;
1677         }
1678
1679         i = (int *) tbl_data;
1680         vleft = table->maxlen / sizeof(*i);
1681         left = *lenp;
1682
1683         if (!conv)
1684                 conv = do_proc_dointvec_conv;
1685
1686         for (; left && vleft--; i++, first=0) {
1687                 if (write) {
1688                         while (left) {
1689                                 char c;
1690                                 if (get_user(c, s))
1691                                         return -EFAULT;
1692                                 if (!isspace(c))
1693                                         break;
1694                                 left--;
1695                                 s++;
1696                         }
1697                         if (!left)
1698                                 break;
1699                         neg = 0;
1700                         len = left;
1701                         if (len > sizeof(buf) - 1)
1702                                 len = sizeof(buf) - 1;
1703                         if (copy_from_user(buf, s, len))
1704                                 return -EFAULT;
1705                         buf[len] = 0;
1706                         p = buf;
1707                         if (*p == '-' && left > 1) {
1708                                 neg = 1;
1709                                 p++;
1710                         }
1711                         if (*p < '0' || *p > '9')
1712                                 break;
1713
1714                         lval = simple_strtoul(p, &p, 0);
1715
1716                         len = p-buf;
1717                         if ((len < left) && *p && !isspace(*p))
1718                                 break;
1719                         if (neg)
1720                                 val = -val;
1721                         s += len;
1722                         left -= len;
1723
1724                         if (conv(&neg, &lval, i, 1, data))
1725                                 break;
1726                 } else {
1727                         p = buf;
1728                         if (!first)
1729                                 *p++ = '\t';
1730
1731                         if (conv(&neg, &lval, i, 0, data))
1732                                 break;
1733
1734                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1735                         len = strlen(buf);
1736                         if (len > left)
1737                                 len = left;
1738                         if(copy_to_user(s, buf, len))
1739                                 return -EFAULT;
1740                         left -= len;
1741                         s += len;
1742                 }
1743         }
1744
1745         if (!write && !first && left) {
1746                 if(put_user('\n', s))
1747                         return -EFAULT;
1748                 left--, s++;
1749         }
1750         if (write) {
1751                 while (left) {
1752                         char c;
1753                         if (get_user(c, s++))
1754                                 return -EFAULT;
1755                         if (!isspace(c))
1756                                 break;
1757                         left--;
1758                 }
1759         }
1760         if (write && first)
1761                 return -EINVAL;
1762         *lenp -= left;
1763         *ppos += *lenp;
1764         return 0;
1765 #undef TMPBUFLEN
1766 }
1767
1768 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1769                   void __user *buffer, size_t *lenp, loff_t *ppos,
1770                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1771                               int write, void *data),
1772                   void *data)
1773 {
1774         return __do_proc_dointvec(table->data, table, write, filp,
1775                         buffer, lenp, ppos, conv, data);
1776 }
1777
1778 /**
1779  * proc_dointvec - read a vector of integers
1780  * @table: the sysctl table
1781  * @write: %TRUE if this is a write to the sysctl file
1782  * @filp: the file structure
1783  * @buffer: the user buffer
1784  * @lenp: the size of the user buffer
1785  * @ppos: file position
1786  *
1787  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1788  * values from/to the user buffer, treated as an ASCII string.
1789  *
1790  * Returns 0 on success.
1791  */
1792 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1793                      void __user *buffer, size_t *lenp, loff_t *ppos)
1794 {
1795     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1796                             NULL,NULL);
1797 }
1798
1799 #define OP_SET  0
1800 #define OP_AND  1
1801 #define OP_OR   2
1802
1803 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1804                                       int *valp,
1805                                       int write, void *data)
1806 {
1807         int op = *(int *)data;
1808         if (write) {
1809                 int val = *negp ? -*lvalp : *lvalp;
1810                 switch(op) {
1811                 case OP_SET:    *valp = val; break;
1812                 case OP_AND:    *valp &= val; break;
1813                 case OP_OR:     *valp |= val; break;
1814                 }
1815         } else {
1816                 int val = *valp;
1817                 if (val < 0) {
1818                         *negp = -1;
1819                         *lvalp = (unsigned long)-val;
1820                 } else {
1821                         *negp = 0;
1822                         *lvalp = (unsigned long)val;
1823                 }
1824         }
1825         return 0;
1826 }
1827
1828 /*
1829  *      init may raise the set.
1830  */
1831
1832 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1833                         void __user *buffer, size_t *lenp, loff_t *ppos)
1834 {
1835         int op;
1836
1837         if (write && !capable(CAP_SYS_MODULE)) {
1838                 return -EPERM;
1839         }
1840
1841         op = is_init(current) ? OP_SET : OP_AND;
1842         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1843                                 do_proc_dointvec_bset_conv,&op);
1844 }
1845
1846 /*
1847  *      Taint values can only be increased
1848  */
1849 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1850                                void __user *buffer, size_t *lenp, loff_t *ppos)
1851 {
1852         int op;
1853
1854         if (write && !capable(CAP_SYS_ADMIN))
1855                 return -EPERM;
1856
1857         op = OP_OR;
1858         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1859                                 do_proc_dointvec_bset_conv,&op);
1860 }
1861
1862 struct do_proc_dointvec_minmax_conv_param {
1863         int *min;
1864         int *max;
1865 };
1866
1867 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1868                                         int *valp,
1869                                         int write, void *data)
1870 {
1871         struct do_proc_dointvec_minmax_conv_param *param = data;
1872         if (write) {
1873                 int val = *negp ? -*lvalp : *lvalp;
1874                 if ((param->min && *param->min > val) ||
1875                     (param->max && *param->max < val))
1876                         return -EINVAL;
1877                 *valp = val;
1878         } else {
1879                 int val = *valp;
1880                 if (val < 0) {
1881                         *negp = -1;
1882                         *lvalp = (unsigned long)-val;
1883                 } else {
1884                         *negp = 0;
1885                         *lvalp = (unsigned long)val;
1886                 }
1887         }
1888         return 0;
1889 }
1890
1891 /**
1892  * proc_dointvec_minmax - read a vector of integers with min/max values
1893  * @table: the sysctl table
1894  * @write: %TRUE if this is a write to the sysctl file
1895  * @filp: the file structure
1896  * @buffer: the user buffer
1897  * @lenp: the size of the user buffer
1898  * @ppos: file position
1899  *
1900  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1901  * values from/to the user buffer, treated as an ASCII string.
1902  *
1903  * This routine will ensure the values are within the range specified by
1904  * table->extra1 (min) and table->extra2 (max).
1905  *
1906  * Returns 0 on success.
1907  */
1908 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1909                   void __user *buffer, size_t *lenp, loff_t *ppos)
1910 {
1911         struct do_proc_dointvec_minmax_conv_param param = {
1912                 .min = (int *) table->extra1,
1913                 .max = (int *) table->extra2,
1914         };
1915         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1916                                 do_proc_dointvec_minmax_conv, &param);
1917 }
1918
1919 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1920                                      struct file *filp,
1921                                      void __user *buffer,
1922                                      size_t *lenp, loff_t *ppos,
1923                                      unsigned long convmul,
1924                                      unsigned long convdiv)
1925 {
1926 #define TMPBUFLEN 21
1927         unsigned long *i, *min, *max, val;
1928         int vleft, first=1, neg;
1929         size_t len, left;
1930         char buf[TMPBUFLEN], *p;
1931         char __user *s = buffer;
1932
1933         if (!data || !table->maxlen || !*lenp ||
1934             (*ppos && !write)) {
1935                 *lenp = 0;
1936                 return 0;
1937         }
1938
1939         i = (unsigned long *) data;
1940         min = (unsigned long *) table->extra1;
1941         max = (unsigned long *) table->extra2;
1942         vleft = table->maxlen / sizeof(unsigned long);
1943         left = *lenp;
1944
1945         for (; left && vleft--; i++, min++, max++, first=0) {
1946                 if (write) {
1947                         while (left) {
1948                                 char c;
1949                                 if (get_user(c, s))
1950                                         return -EFAULT;
1951                                 if (!isspace(c))
1952                                         break;
1953                                 left--;
1954                                 s++;
1955                         }
1956                         if (!left)
1957                                 break;
1958                         neg = 0;
1959                         len = left;
1960                         if (len > TMPBUFLEN-1)
1961                                 len = TMPBUFLEN-1;
1962                         if (copy_from_user(buf, s, len))
1963                                 return -EFAULT;
1964                         buf[len] = 0;
1965                         p = buf;
1966                         if (*p == '-' && left > 1) {
1967                                 neg = 1;
1968                                 p++;
1969                         }
1970                         if (*p < '0' || *p > '9')
1971                                 break;
1972                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1973                         len = p-buf;
1974                         if ((len < left) && *p && !isspace(*p))
1975                                 break;
1976                         if (neg)
1977                                 val = -val;
1978                         s += len;
1979                         left -= len;
1980
1981                         if(neg)
1982                                 continue;
1983                         if ((min && val < *min) || (max && val > *max))
1984                                 continue;
1985                         *i = val;
1986                 } else {
1987                         p = buf;
1988                         if (!first)
1989                                 *p++ = '\t';
1990                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1991                         len = strlen(buf);
1992                         if (len > left)
1993                                 len = left;
1994                         if(copy_to_user(s, buf, len))
1995                                 return -EFAULT;
1996                         left -= len;
1997                         s += len;
1998                 }
1999         }
2000
2001         if (!write && !first && left) {
2002                 if(put_user('\n', s))
2003                         return -EFAULT;
2004                 left--, s++;
2005         }
2006         if (write) {
2007                 while (left) {
2008                         char c;
2009                         if (get_user(c, s++))
2010                                 return -EFAULT;
2011                         if (!isspace(c))
2012                                 break;
2013                         left--;
2014                 }
2015         }
2016         if (write && first)
2017                 return -EINVAL;
2018         *lenp -= left;
2019         *ppos += *lenp;
2020         return 0;
2021 #undef TMPBUFLEN
2022 }
2023
2024 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2025                                      struct file *filp,
2026                                      void __user *buffer,
2027                                      size_t *lenp, loff_t *ppos,
2028                                      unsigned long convmul,
2029                                      unsigned long convdiv)
2030 {
2031         return __do_proc_doulongvec_minmax(table->data, table, write,
2032                         filp, buffer, lenp, ppos, convmul, convdiv);
2033 }
2034
2035 /**
2036  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2037  * @table: the sysctl table
2038  * @write: %TRUE if this is a write to the sysctl file
2039  * @filp: the file structure
2040  * @buffer: the user buffer
2041  * @lenp: the size of the user buffer
2042  * @ppos: file position
2043  *
2044  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2045  * values from/to the user buffer, treated as an ASCII string.
2046  *
2047  * This routine will ensure the values are within the range specified by
2048  * table->extra1 (min) and table->extra2 (max).
2049  *
2050  * Returns 0 on success.
2051  */
2052 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2053                            void __user *buffer, size_t *lenp, loff_t *ppos)
2054 {
2055     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2056 }
2057
2058 /**
2059  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2060  * @table: the sysctl table
2061  * @write: %TRUE if this is a write to the sysctl file
2062  * @filp: the file structure
2063  * @buffer: the user buffer
2064  * @lenp: the size of the user buffer
2065  * @ppos: file position
2066  *
2067  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2068  * values from/to the user buffer, treated as an ASCII string. The values
2069  * are treated as milliseconds, and converted to jiffies when they are stored.
2070  *
2071  * This routine will ensure the values are within the range specified by
2072  * table->extra1 (min) and table->extra2 (max).
2073  *
2074  * Returns 0 on success.
2075  */
2076 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2077                                       struct file *filp,
2078                                       void __user *buffer,
2079                                       size_t *lenp, loff_t *ppos)
2080 {
2081     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2082                                      lenp, ppos, HZ, 1000l);
2083 }
2084
2085
2086 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2087                                          int *valp,
2088                                          int write, void *data)
2089 {
2090         if (write) {
2091                 if (*lvalp > LONG_MAX / HZ)
2092                         return 1;
2093                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2094         } else {
2095                 int val = *valp;
2096                 unsigned long lval;
2097                 if (val < 0) {
2098                         *negp = -1;
2099                         lval = (unsigned long)-val;
2100                 } else {
2101                         *negp = 0;
2102                         lval = (unsigned long)val;
2103                 }
2104                 *lvalp = lval / HZ;
2105         }
2106         return 0;
2107 }
2108
2109 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2110                                                 int *valp,
2111                                                 int write, void *data)
2112 {
2113         if (write) {
2114                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2115                         return 1;
2116                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2117         } else {
2118                 int val = *valp;
2119                 unsigned long lval;
2120                 if (val < 0) {
2121                         *negp = -1;
2122                         lval = (unsigned long)-val;
2123                 } else {
2124                         *negp = 0;
2125                         lval = (unsigned long)val;
2126                 }
2127                 *lvalp = jiffies_to_clock_t(lval);
2128         }
2129         return 0;
2130 }
2131
2132 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2133                                             int *valp,
2134                                             int write, void *data)
2135 {
2136         if (write) {
2137                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2138         } else {
2139                 int val = *valp;
2140                 unsigned long lval;
2141                 if (val < 0) {
2142                         *negp = -1;
2143                         lval = (unsigned long)-val;
2144                 } else {
2145                         *negp = 0;
2146                         lval = (unsigned long)val;
2147                 }
2148                 *lvalp = jiffies_to_msecs(lval);
2149         }
2150         return 0;
2151 }
2152
2153 /**
2154  * proc_dointvec_jiffies - read a vector of integers as seconds
2155  * @table: the sysctl table
2156  * @write: %TRUE if this is a write to the sysctl file
2157  * @filp: the file structure
2158  * @buffer: the user buffer
2159  * @lenp: the size of the user buffer
2160  * @ppos: file position
2161  *
2162  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2163  * values from/to the user buffer, treated as an ASCII string.
2164  * The values read are assumed to be in seconds, and are converted into
2165  * jiffies.
2166  *
2167  * Returns 0 on success.
2168  */
2169 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2170                           void __user *buffer, size_t *lenp, loff_t *ppos)
2171 {
2172     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2173                             do_proc_dointvec_jiffies_conv,NULL);
2174 }
2175
2176 /**
2177  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2178  * @table: the sysctl table
2179  * @write: %TRUE if this is a write to the sysctl file
2180  * @filp: the file structure
2181  * @buffer: the user buffer
2182  * @lenp: the size of the user buffer
2183  * @ppos: pointer to the file position
2184  *
2185  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2186  * values from/to the user buffer, treated as an ASCII string.
2187  * The values read are assumed to be in 1/USER_HZ seconds, and
2188  * are converted into jiffies.
2189  *
2190  * Returns 0 on success.
2191  */
2192 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2193                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2194 {
2195     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2196                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2197 }
2198
2199 /**
2200  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2201  * @table: the sysctl table
2202  * @write: %TRUE if this is a write to the sysctl file
2203  * @filp: the file structure
2204  * @buffer: the user buffer
2205  * @lenp: the size of the user buffer
2206  * @ppos: file position
2207  * @ppos: the current position in the file
2208  *
2209  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2210  * values from/to the user buffer, treated as an ASCII string.
2211  * The values read are assumed to be in 1/1000 seconds, and
2212  * are converted into jiffies.
2213  *
2214  * Returns 0 on success.
2215  */
2216 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2217                              void __user *buffer, size_t *lenp, loff_t *ppos)
2218 {
2219         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2220                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2221 }
2222
2223 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2224                            void __user *buffer, size_t *lenp, loff_t *ppos)
2225 {
2226         struct pid *new_pid;
2227         pid_t tmp;
2228         int r;
2229
2230         tmp = pid_nr(cad_pid);
2231
2232         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2233                                lenp, ppos, NULL, NULL);
2234         if (r || !write)
2235                 return r;
2236
2237         new_pid = find_get_pid(tmp);
2238         if (!new_pid)
2239                 return -ESRCH;
2240
2241         put_pid(xchg(&cad_pid, new_pid));
2242         return 0;
2243 }
2244
2245 #else /* CONFIG_PROC_FS */
2246
2247 int proc_dostring(ctl_table *table, int write, struct file *filp,
2248                   void __user *buffer, size_t *lenp, loff_t *ppos)
2249 {
2250         return -ENOSYS;
2251 }
2252
2253 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2254                   void __user *buffer, size_t *lenp, loff_t *ppos)
2255 {
2256         return -ENOSYS;
2257 }
2258
2259 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2260                         void __user *buffer, size_t *lenp, loff_t *ppos)
2261 {
2262         return -ENOSYS;
2263 }
2264
2265 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2266                     void __user *buffer, size_t *lenp, loff_t *ppos)
2267 {
2268         return -ENOSYS;
2269 }
2270
2271 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2272                     void __user *buffer, size_t *lenp, loff_t *ppos)
2273 {
2274         return -ENOSYS;
2275 }
2276
2277 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2278                     void __user *buffer, size_t *lenp, loff_t *ppos)
2279 {
2280         return -ENOSYS;
2281 }
2282
2283 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2284                              void __user *buffer, size_t *lenp, loff_t *ppos)
2285 {
2286         return -ENOSYS;
2287 }
2288
2289 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2290                     void __user *buffer, size_t *lenp, loff_t *ppos)
2291 {
2292         return -ENOSYS;
2293 }
2294
2295 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2296                                       struct file *filp,
2297                                       void __user *buffer,
2298                                       size_t *lenp, loff_t *ppos)
2299 {
2300     return -ENOSYS;
2301 }
2302
2303
2304 #endif /* CONFIG_PROC_FS */
2305
2306
2307 #ifdef CONFIG_SYSCTL_SYSCALL
2308 /*
2309  * General sysctl support routines
2310  */
2311
2312 /* The generic string strategy routine: */
2313 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2314                   void __user *oldval, size_t __user *oldlenp,
2315                   void __user *newval, size_t newlen)
2316 {
2317         if (!table->data || !table->maxlen)
2318                 return -ENOTDIR;
2319
2320         if (oldval && oldlenp) {
2321                 size_t bufsize;
2322                 if (get_user(bufsize, oldlenp))
2323                         return -EFAULT;
2324                 if (bufsize) {
2325                         size_t len = strlen(table->data), copied;
2326
2327                         /* This shouldn't trigger for a well-formed sysctl */
2328                         if (len > table->maxlen)
2329                                 len = table->maxlen;
2330
2331                         /* Copy up to a max of bufsize-1 bytes of the string */
2332                         copied = (len >= bufsize) ? bufsize - 1 : len;
2333
2334                         if (copy_to_user(oldval, table->data, copied) ||
2335                             put_user(0, (char __user *)(oldval + copied)))
2336                                 return -EFAULT;
2337                         if (put_user(len, oldlenp))
2338                                 return -EFAULT;
2339                 }
2340         }
2341         if (newval && newlen) {
2342                 size_t len = newlen;
2343                 if (len > table->maxlen)
2344                         len = table->maxlen;
2345                 if(copy_from_user(table->data, newval, len))
2346                         return -EFAULT;
2347                 if (len == table->maxlen)
2348                         len--;
2349                 ((char *) table->data)[len] = 0;
2350         }
2351         return 1;
2352 }
2353
2354 /*
2355  * This function makes sure that all of the integers in the vector
2356  * are between the minimum and maximum values given in the arrays
2357  * table->extra1 and table->extra2, respectively.
2358  */
2359 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2360                 void __user *oldval, size_t __user *oldlenp,
2361                 void __user *newval, size_t newlen)
2362 {
2363
2364         if (newval && newlen) {
2365                 int __user *vec = (int __user *) newval;
2366                 int *min = (int *) table->extra1;
2367                 int *max = (int *) table->extra2;
2368                 size_t length;
2369                 int i;
2370
2371                 if (newlen % sizeof(int) != 0)
2372                         return -EINVAL;
2373
2374                 if (!table->extra1 && !table->extra2)
2375                         return 0;
2376
2377                 if (newlen > table->maxlen)
2378                         newlen = table->maxlen;
2379                 length = newlen / sizeof(int);
2380
2381                 for (i = 0; i < length; i++) {
2382                         int value;
2383                         if (get_user(value, vec + i))
2384                                 return -EFAULT;
2385                         if (min && value < min[i])
2386                                 return -EINVAL;
2387                         if (max && value > max[i])
2388                                 return -EINVAL;
2389                 }
2390         }
2391         return 0;
2392 }
2393
2394 /* Strategy function to convert jiffies to seconds */
2395 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2396                 void __user *oldval, size_t __user *oldlenp,
2397                 void __user *newval, size_t newlen)
2398 {
2399         if (oldval && oldlenp) {
2400                 size_t olen;
2401
2402                 if (get_user(olen, oldlenp))
2403                         return -EFAULT;
2404                 if (olen) {
2405                         int val;
2406
2407                         if (olen < sizeof(int))
2408                                 return -EINVAL;
2409
2410                         val = *(int *)(table->data) / HZ;
2411                         if (put_user(val, (int __user *)oldval))
2412                                 return -EFAULT;
2413                         if (put_user(sizeof(int), oldlenp))
2414                                 return -EFAULT;
2415                 }
2416         }
2417         if (newval && newlen) {
2418                 int new;
2419                 if (newlen != sizeof(int))
2420                         return -EINVAL;
2421                 if (get_user(new, (int __user *)newval))
2422                         return -EFAULT;
2423                 *(int *)(table->data) = new*HZ;
2424         }
2425         return 1;
2426 }
2427
2428 /* Strategy function to convert jiffies to seconds */
2429 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2430                 void __user *oldval, size_t __user *oldlenp,
2431                 void __user *newval, size_t newlen)
2432 {
2433         if (oldval && oldlenp) {
2434                 size_t olen;
2435
2436                 if (get_user(olen, oldlenp))
2437                         return -EFAULT;
2438                 if (olen) {
2439                         int val;
2440
2441                         if (olen < sizeof(int))
2442                                 return -EINVAL;
2443
2444                         val = jiffies_to_msecs(*(int *)(table->data));
2445                         if (put_user(val, (int __user *)oldval))
2446                                 return -EFAULT;
2447                         if (put_user(sizeof(int), oldlenp))
2448                                 return -EFAULT;
2449                 }
2450         }
2451         if (newval && newlen) {
2452                 int new;
2453                 if (newlen != sizeof(int))
2454                         return -EINVAL;
2455                 if (get_user(new, (int __user *)newval))
2456                         return -EFAULT;
2457                 *(int *)(table->data) = msecs_to_jiffies(new);
2458         }
2459         return 1;
2460 }
2461
2462
2463
2464 #else /* CONFIG_SYSCTL_SYSCALL */
2465
2466
2467 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2468 {
2469         static int msg_count;
2470         struct __sysctl_args tmp;
2471         int name[CTL_MAXNAME];
2472         int i;
2473
2474         /* Read in the sysctl name for better debug message logging */
2475         if (copy_from_user(&tmp, args, sizeof(tmp)))
2476                 return -EFAULT;
2477         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2478                 return -ENOTDIR;
2479         for (i = 0; i < tmp.nlen; i++)
2480                 if (get_user(name[i], tmp.name + i))
2481                         return -EFAULT;
2482
2483         /* Ignore accesses to kernel.version */
2484         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2485                 goto out;
2486
2487         if (msg_count < 5) {
2488                 msg_count++;
2489                 printk(KERN_INFO
2490                         "warning: process `%s' used the removed sysctl "
2491                         "system call with ", current->comm);
2492                 for (i = 0; i < tmp.nlen; i++)
2493                         printk("%d.", name[i]);
2494                 printk("\n");
2495         }
2496 out:
2497         return -ENOSYS;
2498 }
2499
2500 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2501                   void __user *oldval, size_t __user *oldlenp,
2502                   void __user *newval, size_t newlen)
2503 {
2504         return -ENOSYS;
2505 }
2506
2507 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2508                 void __user *oldval, size_t __user *oldlenp,
2509                 void __user *newval, size_t newlen)
2510 {
2511         return -ENOSYS;
2512 }
2513
2514 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2515                 void __user *oldval, size_t __user *oldlenp,
2516                 void __user *newval, size_t newlen)
2517 {
2518         return -ENOSYS;
2519 }
2520
2521 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2522                 void __user *oldval, size_t __user *oldlenp,
2523                 void __user *newval, size_t newlen)
2524 {
2525         return -ENOSYS;
2526 }
2527
2528 #endif /* CONFIG_SYSCTL_SYSCALL */
2529
2530 /*
2531  * No sense putting this after each symbol definition, twice,
2532  * exception granted :-)
2533  */
2534 EXPORT_SYMBOL(proc_dointvec);
2535 EXPORT_SYMBOL(proc_dointvec_jiffies);
2536 EXPORT_SYMBOL(proc_dointvec_minmax);
2537 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2538 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2539 EXPORT_SYMBOL(proc_dostring);
2540 EXPORT_SYMBOL(proc_doulongvec_minmax);
2541 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2542 EXPORT_SYMBOL(register_sysctl_table);
2543 EXPORT_SYMBOL(sysctl_intvec);
2544 EXPORT_SYMBOL(sysctl_jiffies);
2545 EXPORT_SYMBOL(sysctl_ms_jiffies);
2546 EXPORT_SYMBOL(sysctl_string);
2547 EXPORT_SYMBOL(unregister_sysctl_table);