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/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/hugetlb.h>
  40 #include <linux/initrd.h>
  41 #include <linux/key.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/vmstat.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50 #include <linux/ftrace.h>
  51 #include <linux/slow-work.h>
  52
  53 #include <asm/uaccess.h>
  54 #include <asm/processor.h>
  55
  56 #ifdef CONFIG_X86
  57 #include <asm/nmi.h>
  58 #include <asm/stacktrace.h>
  59 #include <asm/io.h>
  60 #endif
  61
  62 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  63
  64 #if defined(CONFIG_SYSCTL)
  65
  66 /* External variables not in a header file. */
  67 extern int C_A_D;
  68 extern int print_fatal_signals;
  69 extern int sysctl_overcommit_memory;
  70 extern int sysctl_overcommit_ratio;
  71 extern int sysctl_panic_on_oom;
  72 extern int sysctl_oom_kill_allocating_task;
  73 extern int sysctl_oom_dump_tasks;
  74 extern int max_threads;
  75 extern int core_uses_pid;
  76 extern int suid_dumpable;
  77 extern char core_pattern[];
  78 extern int pid_max;
  79 extern int min_free_kbytes;
  80 extern int pid_max_min, pid_max_max;
  81 extern int sysctl_drop_caches;
  82 extern int percpu_pagelist_fraction;
  83 extern int compat_log;
  84 extern int latencytop_enabled;
  85 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  86 #ifndef CONFIG_MMU
  87 extern int sysctl_nr_trim_pages;
  88 #endif
  89 #ifdef CONFIG_RCU_TORTURE_TEST
  90 extern int rcutorture_runnable;
  91 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  92
  93 /* Constants used for minimum and  maximum */
  94 #ifdef CONFIG_DETECT_SOFTLOCKUP
  95 static int sixty = 60;
  96 static int neg_one = -1;
  97 #endif
  98
  99 static int zero;
 100 static int __maybe_unused one = 1;
 101 static int __maybe_unused two = 2;
 102 static unsigned long one_ul = 1;
 103 static int one_hundred = 100;
 104 static int one_thousand = 1000;
 105
 106 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 107 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 108
 109 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 110 static int maxolduid = 65535;
 111 static int minolduid;
 112 static int min_percpu_pagelist_fract = 8;
 113
 114 static int ngroups_max = NGROUPS_MAX;
 115
 116 #ifdef CONFIG_MODULES
 117 extern char modprobe_path[];
 118 extern int modules_disabled;
 119 #endif
 120 #ifdef CONFIG_CHR_DEV_SG
 121 extern int sg_big_buff;
 122 #endif
 123
 124 #ifdef CONFIG_SPARC
 125 #include <asm/system.h>
 126 #endif
 127
 128 #ifdef CONFIG_SPARC64
 129 extern int sysctl_tsb_ratio;
 130 #endif
 131
 132 #ifdef __hppa__
 133 extern int pwrsw_enabled;
 134 extern int unaligned_enabled;
 135 #endif
 136
 137 #ifdef CONFIG_S390
 138 #ifdef CONFIG_MATHEMU
 139 extern int sysctl_ieee_emulation_warnings;
 140 #endif
 141 extern int sysctl_userprocess_debug;
 142 extern int spin_retry;
 143 #endif
 144
 145 #ifdef CONFIG_BSD_PROCESS_ACCT
 146 extern int acct_parm[];
 147 #endif
 148
 149 #ifdef CONFIG_IA64
 150 extern int no_unaligned_warning;
 151 extern int unaligned_dump_stack;
 152 #endif
 153
 154 #ifdef CONFIG_RT_MUTEXES
 155 extern int max_lock_depth;
 156 #endif
 157
 158 #ifdef CONFIG_PROC_SYSCTL
 159 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 160                   void __user *buffer, size_t *lenp, loff_t *ppos);
 161 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 162                                void __user *buffer, size_t *lenp, loff_t *ppos);
 163 #endif
 164
 165 static struct ctl_table root_table[];
 166 static struct ctl_table_root sysctl_table_root;
 167 static struct ctl_table_header root_table_header = {
 168         .count = 1,
 169         .ctl_table = root_table,
 170         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 171         .root = &sysctl_table_root,
 172         .set = &sysctl_table_root.default_set,
 173 };
 174 static struct ctl_table_root sysctl_table_root = {
 175         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 176         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 177 };
 178
 179 static struct ctl_table kern_table[];
 180 static struct ctl_table vm_table[];
 181 static struct ctl_table fs_table[];
 182 static struct ctl_table debug_table[];
 183 static struct ctl_table dev_table[];
 184 extern struct ctl_table random_table[];
 185 #ifdef CONFIG_INOTIFY_USER
 186 extern struct ctl_table inotify_table[];
 187 #endif
 188 #ifdef CONFIG_EPOLL
 189 extern struct ctl_table epoll_table[];
 190 #endif
 191
 192 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 193 int sysctl_legacy_va_layout;
 194 #endif
 195
 196 extern int prove_locking;
 197 extern int lock_stat;
 198
 199 /* The default sysctl tables: */
 200
 201 static struct ctl_table root_table[] = {
 202         {
 203                 .ctl_name       = CTL_KERN,
 204                 .procname       = "kernel",
 205                 .mode           = 0555,
 206                 .child          = kern_table,
 207         },
 208         {
 209                 .ctl_name       = CTL_VM,
 210                 .procname       = "vm",
 211                 .mode           = 0555,
 212                 .child          = vm_table,
 213         },
 214         {
 215                 .ctl_name       = CTL_FS,
 216                 .procname       = "fs",
 217                 .mode           = 0555,
 218                 .child          = fs_table,
 219         },
 220         {
 221                 .ctl_name       = CTL_DEBUG,
 222                 .procname       = "debug",
 223                 .mode           = 0555,
 224                 .child          = debug_table,
 225         },
 226         {
 227                 .ctl_name       = CTL_DEV,
 228                 .procname       = "dev",
 229                 .mode           = 0555,
 230                 .child          = dev_table,
 231         },
 232 /*
 233  * NOTE: do not add new entries to this table unless you have read
 234  * Documentation/sysctl/ctl_unnumbered.txt
 235  */
 236         { .ctl_name = 0 }
 237 };
 238
 239 #ifdef CONFIG_SCHED_DEBUG
 240 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 241 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 242 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 243 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 244 #endif
 245
 246 static struct ctl_table kern_table[] = {
 247 #ifdef CONFIG_SCHED_DEBUG
 248         {
 249                 .ctl_name       = CTL_UNNUMBERED,
 250                 .procname       = "sched_min_granularity_ns",
 251                 .data           = &sysctl_sched_min_granularity,
 252                 .maxlen         = sizeof(unsigned int),
 253                 .mode           = 0644,
 254                 .proc_handler   = &sched_nr_latency_handler,
 255                 .strategy       = &sysctl_intvec,
 256                 .extra1         = &min_sched_granularity_ns,
 257                 .extra2         = &max_sched_granularity_ns,
 258         },
 259         {
 260                 .ctl_name       = CTL_UNNUMBERED,
 261                 .procname       = "sched_latency_ns",
 262                 .data           = &sysctl_sched_latency,
 263                 .maxlen         = sizeof(unsigned int),
 264                 .mode           = 0644,
 265                 .proc_handler   = &sched_nr_latency_handler,
 266                 .strategy       = &sysctl_intvec,
 267                 .extra1         = &min_sched_granularity_ns,
 268                 .extra2         = &max_sched_granularity_ns,
 269         },
 270         {
 271                 .ctl_name       = CTL_UNNUMBERED,
 272                 .procname       = "sched_wakeup_granularity_ns",
 273                 .data           = &sysctl_sched_wakeup_granularity,
 274                 .maxlen         = sizeof(unsigned int),
 275                 .mode           = 0644,
 276                 .proc_handler   = &proc_dointvec_minmax,
 277                 .strategy       = &sysctl_intvec,
 278                 .extra1         = &min_wakeup_granularity_ns,
 279                 .extra2         = &max_wakeup_granularity_ns,
 280         },
 281         {
 282                 .ctl_name       = CTL_UNNUMBERED,
 283                 .procname       = "sched_shares_ratelimit",
 284                 .data           = &sysctl_sched_shares_ratelimit,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289         {
 290                 .ctl_name       = CTL_UNNUMBERED,
 291                 .procname       = "sched_shares_thresh",
 292                 .data           = &sysctl_sched_shares_thresh,
 293                 .maxlen         = sizeof(unsigned int),
 294                 .mode           = 0644,
 295                 .proc_handler   = &proc_dointvec_minmax,
 296                 .strategy       = &sysctl_intvec,
 297                 .extra1         = &zero,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_child_runs_first",
 302                 .data           = &sysctl_sched_child_runs_first,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec,
 306         },
 307         {
 308                 .ctl_name       = CTL_UNNUMBERED,
 309                 .procname       = "sched_features",
 310                 .data           = &sysctl_sched_features,
 311                 .maxlen         = sizeof(unsigned int),
 312                 .mode           = 0644,
 313                 .proc_handler   = &proc_dointvec,
 314         },
 315         {
 316                 .ctl_name       = CTL_UNNUMBERED,
 317                 .procname       = "sched_migration_cost",
 318                 .data           = &sysctl_sched_migration_cost,
 319                 .maxlen         = sizeof(unsigned int),
 320                 .mode           = 0644,
 321                 .proc_handler   = &proc_dointvec,
 322         },
 323         {
 324                 .ctl_name       = CTL_UNNUMBERED,
 325                 .procname       = "sched_nr_migrate",
 326                 .data           = &sysctl_sched_nr_migrate,
 327                 .maxlen         = sizeof(unsigned int),
 328                 .mode           = 0644,
 329                 .proc_handler   = &proc_dointvec,
 330         },
 331 #endif
 332         {
 333                 .ctl_name       = CTL_UNNUMBERED,
 334                 .procname       = "sched_rt_period_us",
 335                 .data           = &sysctl_sched_rt_period,
 336                 .maxlen         = sizeof(unsigned int),
 337                 .mode           = 0644,
 338                 .proc_handler   = &sched_rt_handler,
 339         },
 340         {
 341                 .ctl_name       = CTL_UNNUMBERED,
 342                 .procname       = "sched_rt_runtime_us",
 343                 .data           = &sysctl_sched_rt_runtime,
 344                 .maxlen         = sizeof(int),
 345                 .mode           = 0644,
 346                 .proc_handler   = &sched_rt_handler,
 347         },
 348         {
 349                 .ctl_name       = CTL_UNNUMBERED,
 350                 .procname       = "sched_compat_yield",
 351                 .data           = &sysctl_sched_compat_yield,
 352                 .maxlen         = sizeof(unsigned int),
 353                 .mode           = 0644,
 354                 .proc_handler   = &proc_dointvec,
 355         },
 356 #ifdef CONFIG_PROVE_LOCKING
 357         {
 358                 .ctl_name       = CTL_UNNUMBERED,
 359                 .procname       = "prove_locking",
 360                 .data           = &prove_locking,
 361                 .maxlen         = sizeof(int),
 362                 .mode           = 0644,
 363                 .proc_handler   = &proc_dointvec,
 364         },
 365 #endif
 366 #ifdef CONFIG_LOCK_STAT
 367         {
 368                 .ctl_name       = CTL_UNNUMBERED,
 369                 .procname       = "lock_stat",
 370                 .data           = &lock_stat,
 371                 .maxlen         = sizeof(int),
 372                 .mode           = 0644,
 373                 .proc_handler   = &proc_dointvec,
 374         },
 375 #endif
 376         {
 377                 .ctl_name       = KERN_PANIC,
 378                 .procname       = "panic",
 379                 .data           = &panic_timeout,
 380                 .maxlen         = sizeof(int),
 381                 .mode           = 0644,
 382                 .proc_handler   = &proc_dointvec,
 383         },
 384         {
 385                 .ctl_name       = KERN_CORE_USES_PID,
 386                 .procname       = "core_uses_pid",
 387                 .data           = &core_uses_pid,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = &proc_dointvec,
 391         },
 392         {
 393                 .ctl_name       = KERN_CORE_PATTERN,
 394                 .procname       = "core_pattern",
 395                 .data           = core_pattern,
 396                 .maxlen         = CORENAME_MAX_SIZE,
 397                 .mode           = 0644,
 398                 .proc_handler   = &proc_dostring,
 399                 .strategy       = &sysctl_string,
 400         },
 401 #ifdef CONFIG_PROC_SYSCTL
 402         {
 403                 .procname       = "tainted",
 404                 .maxlen         = sizeof(long),
 405                 .mode           = 0644,
 406                 .proc_handler   = &proc_taint,
 407         },
 408 #endif
 409 #ifdef CONFIG_LATENCYTOP
 410         {
 411                 .procname       = "latencytop",
 412                 .data           = &latencytop_enabled,
 413                 .maxlen         = sizeof(int),
 414                 .mode           = 0644,
 415                 .proc_handler   = &proc_dointvec,
 416         },
 417 #endif
 418 #ifdef CONFIG_BLK_DEV_INITRD
 419         {
 420                 .ctl_name       = KERN_REALROOTDEV,
 421                 .procname       = "real-root-dev",
 422                 .data           = &real_root_dev,
 423                 .maxlen         = sizeof(int),
 424                 .mode           = 0644,
 425                 .proc_handler   = &proc_dointvec,
 426         },
 427 #endif
 428         {
 429                 .ctl_name       = CTL_UNNUMBERED,
 430                 .procname       = "print-fatal-signals",
 431                 .data           = &print_fatal_signals,
 432                 .maxlen         = sizeof(int),
 433                 .mode           = 0644,
 434                 .proc_handler   = &proc_dointvec,
 435         },
 436 #ifdef CONFIG_SPARC
 437         {
 438                 .ctl_name       = KERN_SPARC_REBOOT,
 439                 .procname       = "reboot-cmd",
 440                 .data           = reboot_command,
 441                 .maxlen         = 256,
 442                 .mode           = 0644,
 443                 .proc_handler   = &proc_dostring,
 444                 .strategy       = &sysctl_string,
 445         },
 446         {
 447                 .ctl_name       = KERN_SPARC_STOP_A,
 448                 .procname       = "stop-a",
 449                 .data           = &stop_a_enabled,
 450                 .maxlen         = sizeof (int),
 451                 .mode           = 0644,
 452                 .proc_handler   = &proc_dointvec,
 453         },
 454         {
 455                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 456                 .procname       = "scons-poweroff",
 457                 .data           = &scons_pwroff,
 458                 .maxlen         = sizeof (int),
 459                 .mode           = 0644,
 460                 .proc_handler   = &proc_dointvec,
 461         },
 462 #endif
 463 #ifdef CONFIG_SPARC64
 464         {
 465                 .ctl_name       = CTL_UNNUMBERED,
 466                 .procname       = "tsb-ratio",
 467                 .data           = &sysctl_tsb_ratio,
 468                 .maxlen         = sizeof (int),
 469                 .mode           = 0644,
 470                 .proc_handler   = &proc_dointvec,
 471         },
 472 #endif
 473 #ifdef __hppa__
 474         {
 475                 .ctl_name       = KERN_HPPA_PWRSW,
 476                 .procname       = "soft-power",
 477                 .data           = &pwrsw_enabled,
 478                 .maxlen         = sizeof (int),
 479                 .mode           = 0644,
 480                 .proc_handler   = &proc_dointvec,
 481         },
 482         {
 483                 .ctl_name       = KERN_HPPA_UNALIGNED,
 484                 .procname       = "unaligned-trap",
 485                 .data           = &unaligned_enabled,
 486                 .maxlen         = sizeof (int),
 487                 .mode           = 0644,
 488                 .proc_handler   = &proc_dointvec,
 489         },
 490 #endif
 491         {
 492                 .ctl_name       = KERN_CTLALTDEL,
 493                 .procname       = "ctrl-alt-del",
 494                 .data           = &C_A_D,
 495                 .maxlen         = sizeof(int),
 496                 .mode           = 0644,
 497                 .proc_handler   = &proc_dointvec,
 498         },
 499 #ifdef CONFIG_FUNCTION_TRACER
 500         {
 501                 .ctl_name       = CTL_UNNUMBERED,
 502                 .procname       = "ftrace_enabled",
 503                 .data           = &ftrace_enabled,
 504                 .maxlen         = sizeof(int),
 505                 .mode           = 0644,
 506                 .proc_handler   = &ftrace_enable_sysctl,
 507         },
 508 #endif
 509 #ifdef CONFIG_STACK_TRACER
 510         {
 511                 .ctl_name       = CTL_UNNUMBERED,
 512                 .procname       = "stack_tracer_enabled",
 513                 .data           = &stack_tracer_enabled,
 514                 .maxlen         = sizeof(int),
 515                 .mode           = 0644,
 516                 .proc_handler   = &stack_trace_sysctl,
 517         },
 518 #endif
 519 #ifdef CONFIG_TRACING
 520         {
 521                 .ctl_name       = CTL_UNNUMBERED,
 522                 .procname       = "ftrace_dump_on_oops",
 523                 .data           = &ftrace_dump_on_oops,
 524                 .maxlen         = sizeof(int),
 525                 .mode           = 0644,
 526                 .proc_handler   = &proc_dointvec,
 527         },
 528 #endif
 529 #ifdef CONFIG_MODULES
 530         {
 531                 .ctl_name       = KERN_MODPROBE,
 532                 .procname       = "modprobe",
 533                 .data           = &modprobe_path,
 534                 .maxlen         = KMOD_PATH_LEN,
 535                 .mode           = 0644,
 536                 .proc_handler   = &proc_dostring,
 537                 .strategy       = &sysctl_string,
 538         },
 539         {
 540                 .ctl_name       = CTL_UNNUMBERED,
 541                 .procname       = "modules_disabled",
 542                 .data           = &modules_disabled,
 543                 .maxlen         = sizeof(int),
 544                 .mode           = 0644,
 545                 /* only handle a transition from default "0" to "1" */
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .extra1         = &one,
 548                 .extra2         = &one,
 549         },
 550 #endif
 551 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 552         {
 553                 .ctl_name       = KERN_HOTPLUG,
 554                 .procname       = "hotplug",
 555                 .data           = &uevent_helper,
 556                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 557                 .mode           = 0644,
 558                 .proc_handler   = &proc_dostring,
 559                 .strategy       = &sysctl_string,
 560         },
 561 #endif
 562 #ifdef CONFIG_CHR_DEV_SG
 563         {
 564                 .ctl_name       = KERN_SG_BIG_BUFF,
 565                 .procname       = "sg-big-buff",
 566                 .data           = &sg_big_buff,
 567                 .maxlen         = sizeof (int),
 568                 .mode           = 0444,
 569                 .proc_handler   = &proc_dointvec,
 570         },
 571 #endif
 572 #ifdef CONFIG_BSD_PROCESS_ACCT
 573         {
 574                 .ctl_name       = KERN_ACCT,
 575                 .procname       = "acct",
 576                 .data           = &acct_parm,
 577                 .maxlen         = 3*sizeof(int),
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dointvec,
 580         },
 581 #endif
 582 #ifdef CONFIG_MAGIC_SYSRQ
 583         {
 584                 .ctl_name       = KERN_SYSRQ,
 585                 .procname       = "sysrq",
 586                 .data           = &__sysrq_enabled,
 587                 .maxlen         = sizeof (int),
 588                 .mode           = 0644,
 589                 .proc_handler   = &proc_dointvec,
 590         },
 591 #endif
 592 #ifdef CONFIG_PROC_SYSCTL
 593         {
 594                 .procname       = "cad_pid",
 595                 .data           = NULL,
 596                 .maxlen         = sizeof (int),
 597                 .mode           = 0600,
 598                 .proc_handler   = &proc_do_cad_pid,
 599         },
 600 #endif
 601         {
 602                 .ctl_name       = KERN_MAX_THREADS,
 603                 .procname       = "threads-max",
 604                 .data           = &max_threads,
 605                 .maxlen         = sizeof(int),
 606                 .mode           = 0644,
 607                 .proc_handler   = &proc_dointvec,
 608         },
 609         {
 610                 .ctl_name       = KERN_RANDOM,
 611                 .procname       = "random",
 612                 .mode           = 0555,
 613                 .child          = random_table,
 614         },
 615         {
 616                 .ctl_name       = KERN_OVERFLOWUID,
 617                 .procname       = "overflowuid",
 618                 .data           = &overflowuid,
 619                 .maxlen         = sizeof(int),
 620                 .mode           = 0644,
 621                 .proc_handler   = &proc_dointvec_minmax,
 622                 .strategy       = &sysctl_intvec,
 623                 .extra1         = &minolduid,
 624                 .extra2         = &maxolduid,
 625         },
 626         {
 627                 .ctl_name       = KERN_OVERFLOWGID,
 628                 .procname       = "overflowgid",
 629                 .data           = &overflowgid,
 630                 .maxlen         = sizeof(int),
 631                 .mode           = 0644,
 632                 .proc_handler   = &proc_dointvec_minmax,
 633                 .strategy       = &sysctl_intvec,
 634                 .extra1         = &minolduid,
 635                 .extra2         = &maxolduid,
 636         },
 637 #ifdef CONFIG_S390
 638 #ifdef CONFIG_MATHEMU
 639         {
 640                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 641                 .procname       = "ieee_emulation_warnings",
 642                 .data           = &sysctl_ieee_emulation_warnings,
 643                 .maxlen         = sizeof(int),
 644                 .mode           = 0644,
 645                 .proc_handler   = &proc_dointvec,
 646         },
 647 #endif
 648         {
 649                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 650                 .procname       = "userprocess_debug",
 651                 .data           = &sysctl_userprocess_debug,
 652                 .maxlen         = sizeof(int),
 653                 .mode           = 0644,
 654                 .proc_handler   = &proc_dointvec,
 655         },
 656 #endif
 657         {
 658                 .ctl_name       = KERN_PIDMAX,
 659                 .procname       = "pid_max",
 660                 .data           = &pid_max,
 661                 .maxlen         = sizeof (int),
 662                 .mode           = 0644,
 663                 .proc_handler   = &proc_dointvec_minmax,
 664                 .strategy       = sysctl_intvec,
 665                 .extra1         = &pid_max_min,
 666                 .extra2         = &pid_max_max,
 667         },
 668         {
 669                 .ctl_name       = KERN_PANIC_ON_OOPS,
 670                 .procname       = "panic_on_oops",
 671                 .data           = &panic_on_oops,
 672                 .maxlen         = sizeof(int),
 673                 .mode           = 0644,
 674                 .proc_handler   = &proc_dointvec,
 675         },
 676 #if defined CONFIG_PRINTK
 677         {
 678                 .ctl_name       = KERN_PRINTK,
 679                 .procname       = "printk",
 680                 .data           = &console_loglevel,
 681                 .maxlen         = 4*sizeof(int),
 682                 .mode           = 0644,
 683                 .proc_handler   = &proc_dointvec,
 684         },
 685         {
 686                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 687                 .procname       = "printk_ratelimit",
 688                 .data           = &printk_ratelimit_state.interval,
 689                 .maxlen         = sizeof(int),
 690                 .mode           = 0644,
 691                 .proc_handler   = &proc_dointvec_jiffies,
 692                 .strategy       = &sysctl_jiffies,
 693         },
 694         {
 695                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 696                 .procname       = "printk_ratelimit_burst",
 697                 .data           = &printk_ratelimit_state.burst,
 698                 .maxlen         = sizeof(int),
 699                 .mode           = 0644,
 700                 .proc_handler   = &proc_dointvec,
 701         },
 702 #endif
 703         {
 704                 .ctl_name       = KERN_NGROUPS_MAX,
 705                 .procname       = "ngroups_max",
 706                 .data           = &ngroups_max,
 707                 .maxlen         = sizeof (int),
 708                 .mode           = 0444,
 709                 .proc_handler   = &proc_dointvec,
 710         },
 711 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 712         {
 713                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 714                 .procname       = "unknown_nmi_panic",
 715                 .data           = &unknown_nmi_panic,
 716                 .maxlen         = sizeof (int),
 717                 .mode           = 0644,
 718                 .proc_handler   = &proc_dointvec,
 719         },
 720         {
 721                 .procname       = "nmi_watchdog",
 722                 .data           = &nmi_watchdog_enabled,
 723                 .maxlen         = sizeof (int),
 724                 .mode           = 0644,
 725                 .proc_handler   = &proc_nmi_enabled,
 726         },
 727 #endif
 728 #if defined(CONFIG_X86)
 729         {
 730                 .ctl_name       = KERN_PANIC_ON_NMI,
 731                 .procname       = "panic_on_unrecovered_nmi",
 732                 .data           = &panic_on_unrecovered_nmi,
 733                 .maxlen         = sizeof(int),
 734                 .mode           = 0644,
 735                 .proc_handler   = &proc_dointvec,
 736         },
 737         {
 738                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 739                 .procname       = "bootloader_type",
 740                 .data           = &bootloader_type,
 741                 .maxlen         = sizeof (int),
 742                 .mode           = 0444,
 743                 .proc_handler   = &proc_dointvec,
 744         },
 745         {
 746                 .ctl_name       = CTL_UNNUMBERED,
 747                 .procname       = "kstack_depth_to_print",
 748                 .data           = &kstack_depth_to_print,
 749                 .maxlen         = sizeof(int),
 750                 .mode           = 0644,
 751                 .proc_handler   = &proc_dointvec,
 752         },
 753         {
 754                 .ctl_name       = CTL_UNNUMBERED,
 755                 .procname       = "io_delay_type",
 756                 .data           = &io_delay_type,
 757                 .maxlen         = sizeof(int),
 758                 .mode           = 0644,
 759                 .proc_handler   = &proc_dointvec,
 760         },
 761 #endif
 762 #if defined(CONFIG_MMU)
 763         {
 764                 .ctl_name       = KERN_RANDOMIZE,
 765                 .procname       = "randomize_va_space",
 766                 .data           = &randomize_va_space,
 767                 .maxlen         = sizeof(int),
 768                 .mode           = 0644,
 769                 .proc_handler   = &proc_dointvec,
 770         },
 771 #endif
 772 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 773         {
 774                 .ctl_name       = KERN_SPIN_RETRY,
 775                 .procname       = "spin_retry",
 776                 .data           = &spin_retry,
 777                 .maxlen         = sizeof (int),
 778                 .mode           = 0644,
 779                 .proc_handler   = &proc_dointvec,
 780         },
 781 #endif
 782 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 783         {
 784                 .procname       = "acpi_video_flags",
 785                 .data           = &acpi_realmode_flags,
 786                 .maxlen         = sizeof (unsigned long),
 787                 .mode           = 0644,
 788                 .proc_handler   = &proc_doulongvec_minmax,
 789         },
 790 #endif
 791 #ifdef CONFIG_IA64
 792         {
 793                 .ctl_name       = KERN_IA64_UNALIGNED,
 794                 .procname       = "ignore-unaligned-usertrap",
 795                 .data           = &no_unaligned_warning,
 796                 .maxlen         = sizeof (int),
 797                 .mode           = 0644,
 798                 .proc_handler   = &proc_dointvec,
 799         },
 800         {
 801                 .ctl_name       = CTL_UNNUMBERED,
 802                 .procname       = "unaligned-dump-stack",
 803                 .data           = &unaligned_dump_stack,
 804                 .maxlen         = sizeof (int),
 805                 .mode           = 0644,
 806                 .proc_handler   = &proc_dointvec,
 807         },
 808 #endif
 809 #ifdef CONFIG_DETECT_SOFTLOCKUP
 810         {
 811                 .ctl_name       = CTL_UNNUMBERED,
 812                 .procname       = "softlockup_panic",
 813                 .data           = &softlockup_panic,
 814                 .maxlen         = sizeof(int),
 815                 .mode           = 0644,
 816                 .proc_handler   = &proc_dointvec_minmax,
 817                 .strategy       = &sysctl_intvec,
 818                 .extra1         = &zero,
 819                 .extra2         = &one,
 820         },
 821         {
 822                 .ctl_name       = CTL_UNNUMBERED,
 823                 .procname       = "softlockup_thresh",
 824                 .data           = &softlockup_thresh,
 825                 .maxlen         = sizeof(int),
 826                 .mode           = 0644,
 827                 .proc_handler   = &proc_dosoftlockup_thresh,
 828                 .strategy       = &sysctl_intvec,
 829                 .extra1         = &neg_one,
 830                 .extra2         = &sixty,
 831         },
 832 #endif
 833 #ifdef CONFIG_DETECT_HUNG_TASK
 834         {
 835                 .ctl_name       = CTL_UNNUMBERED,
 836                 .procname       = "hung_task_panic",
 837                 .data           = &sysctl_hung_task_panic,
 838                 .maxlen         = sizeof(int),
 839                 .mode           = 0644,
 840                 .proc_handler   = &proc_dointvec_minmax,
 841                 .strategy       = &sysctl_intvec,
 842                 .extra1         = &zero,
 843                 .extra2         = &one,
 844         },
 845         {
 846                 .ctl_name       = CTL_UNNUMBERED,
 847                 .procname       = "hung_task_check_count",
 848                 .data           = &sysctl_hung_task_check_count,
 849                 .maxlen         = sizeof(unsigned long),
 850                 .mode           = 0644,
 851                 .proc_handler   = &proc_doulongvec_minmax,
 852                 .strategy       = &sysctl_intvec,
 853         },
 854         {
 855                 .ctl_name       = CTL_UNNUMBERED,
 856                 .procname       = "hung_task_timeout_secs",
 857                 .data           = &sysctl_hung_task_timeout_secs,
 858                 .maxlen         = sizeof(unsigned long),
 859                 .mode           = 0644,
 860                 .proc_handler   = &proc_dohung_task_timeout_secs,
 861                 .strategy       = &sysctl_intvec,
 862         },
 863         {
 864                 .ctl_name       = CTL_UNNUMBERED,
 865                 .procname       = "hung_task_warnings",
 866                 .data           = &sysctl_hung_task_warnings,
 867                 .maxlen         = sizeof(unsigned long),
 868                 .mode           = 0644,
 869                 .proc_handler   = &proc_doulongvec_minmax,
 870                 .strategy       = &sysctl_intvec,
 871         },
 872 #endif
 873 #ifdef CONFIG_COMPAT
 874         {
 875                 .ctl_name       = KERN_COMPAT_LOG,
 876                 .procname       = "compat-log",
 877                 .data           = &compat_log,
 878                 .maxlen         = sizeof (int),
 879                 .mode           = 0644,
 880                 .proc_handler   = &proc_dointvec,
 881         },
 882 #endif
 883 #ifdef CONFIG_RT_MUTEXES
 884         {
 885                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 886                 .procname       = "max_lock_depth",
 887                 .data           = &max_lock_depth,
 888                 .maxlen         = sizeof(int),
 889                 .mode           = 0644,
 890                 .proc_handler   = &proc_dointvec,
 891         },
 892 #endif
 893         {
 894                 .ctl_name       = CTL_UNNUMBERED,
 895                 .procname       = "poweroff_cmd",
 896                 .data           = &poweroff_cmd,
 897                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 898                 .mode           = 0644,
 899                 .proc_handler   = &proc_dostring,
 900                 .strategy       = &sysctl_string,
 901         },
 902 #ifdef CONFIG_KEYS
 903         {
 904                 .ctl_name       = CTL_UNNUMBERED,
 905                 .procname       = "keys",
 906                 .mode           = 0555,
 907                 .child          = key_sysctls,
 908         },
 909 #endif
 910 #ifdef CONFIG_RCU_TORTURE_TEST
 911         {
 912                 .ctl_name       = CTL_UNNUMBERED,
 913                 .procname       = "rcutorture_runnable",
 914                 .data           = &rcutorture_runnable,
 915                 .maxlen         = sizeof(int),
 916                 .mode           = 0644,
 917                 .proc_handler   = &proc_dointvec,
 918         },
 919 #endif
 920 #ifdef CONFIG_SLOW_WORK
 921         {
 922                 .ctl_name       = CTL_UNNUMBERED,
 923                 .procname       = "slow-work",
 924                 .mode           = 0555,
 925                 .child          = slow_work_sysctls,
 926         },
 927 #endif
 928 /*
 929  * NOTE: do not add new entries to this table unless you have read
 930  * Documentation/sysctl/ctl_unnumbered.txt
 931  */
 932         { .ctl_name = 0 }
 933 };
 934
 935 static struct ctl_table vm_table[] = {
 936         {
 937                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 938                 .procname       = "overcommit_memory",
 939                 .data           = &sysctl_overcommit_memory,
 940                 .maxlen         = sizeof(sysctl_overcommit_memory),
 941                 .mode           = 0644,
 942                 .proc_handler   = &proc_dointvec,
 943         },
 944         {
 945                 .ctl_name       = VM_PANIC_ON_OOM,
 946                 .procname       = "panic_on_oom",
 947                 .data           = &sysctl_panic_on_oom,
 948                 .maxlen         = sizeof(sysctl_panic_on_oom),
 949                 .mode           = 0644,
 950                 .proc_handler   = &proc_dointvec,
 951         },
 952         {
 953                 .ctl_name       = CTL_UNNUMBERED,
 954                 .procname       = "oom_kill_allocating_task",
 955                 .data           = &sysctl_oom_kill_allocating_task,
 956                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 957                 .mode           = 0644,
 958                 .proc_handler   = &proc_dointvec,
 959         },
 960         {
 961                 .ctl_name       = CTL_UNNUMBERED,
 962                 .procname       = "oom_dump_tasks",
 963                 .data           = &sysctl_oom_dump_tasks,
 964                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 965                 .mode           = 0644,
 966                 .proc_handler   = &proc_dointvec,
 967         },
 968         {
 969                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 970                 .procname       = "overcommit_ratio",
 971                 .data           = &sysctl_overcommit_ratio,
 972                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 973                 .mode           = 0644,
 974                 .proc_handler   = &proc_dointvec,
 975         },
 976         {
 977                 .ctl_name       = VM_PAGE_CLUSTER,
 978                 .procname       = "page-cluster",
 979                 .data           = &page_cluster,
 980                 .maxlen         = sizeof(int),
 981                 .mode           = 0644,
 982                 .proc_handler   = &proc_dointvec,
 983         },
 984         {
 985                 .ctl_name       = VM_DIRTY_BACKGROUND,
 986                 .procname       = "dirty_background_ratio",
 987                 .data           = &dirty_background_ratio,
 988                 .maxlen         = sizeof(dirty_background_ratio),
 989                 .mode           = 0644,
 990                 .proc_handler   = &dirty_background_ratio_handler,
 991                 .strategy       = &sysctl_intvec,
 992                 .extra1         = &zero,
 993                 .extra2         = &one_hundred,
 994         },
 995         {
 996                 .ctl_name       = CTL_UNNUMBERED,
 997                 .procname       = "dirty_background_bytes",
 998                 .data           = &dirty_background_bytes,
 999                 .maxlen         = sizeof(dirty_background_bytes),
1000                 .mode           = 0644,
1001                 .proc_handler   = &dirty_background_bytes_handler,
1002                 .strategy       = &sysctl_intvec,
1003                 .extra1         = &one_ul,
1004         },
1005         {
1006                 .ctl_name       = VM_DIRTY_RATIO,
1007                 .procname       = "dirty_ratio",
1008                 .data           = &vm_dirty_ratio,
1009                 .maxlen         = sizeof(vm_dirty_ratio),
1010                 .mode           = 0644,
1011                 .proc_handler   = &dirty_ratio_handler,
1012                 .strategy       = &sysctl_intvec,
1013                 .extra1         = &zero,
1014                 .extra2         = &one_hundred,
1015         },
1016         {
1017                 .ctl_name       = CTL_UNNUMBERED,
1018                 .procname       = "dirty_bytes",
1019                 .data           = &vm_dirty_bytes,
1020                 .maxlen         = sizeof(vm_dirty_bytes),
1021                 .mode           = 0644,
1022                 .proc_handler   = &dirty_bytes_handler,
1023                 .strategy       = &sysctl_intvec,
1024                 .extra1         = &dirty_bytes_min,
1025         },
1026         {
1027                 .procname       = "dirty_writeback_centisecs",
1028                 .data           = &dirty_writeback_interval,
1029                 .maxlen         = sizeof(dirty_writeback_interval),
1030                 .mode           = 0644,
1031                 .proc_handler   = &dirty_writeback_centisecs_handler,
1032         },
1033         {
1034                 .procname       = "dirty_expire_centisecs",
1035                 .data           = &dirty_expire_interval,
1036                 .maxlen         = sizeof(dirty_expire_interval),
1037                 .mode           = 0644,
1038                 .proc_handler   = &proc_dointvec,
1039         },
1040         {
1041                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1042                 .procname       = "nr_pdflush_threads",
1043                 .data           = &nr_pdflush_threads,
1044                 .maxlen         = sizeof nr_pdflush_threads,
1045                 .mode           = 0444 /* read-only*/,
1046                 .proc_handler   = &proc_dointvec,
1047         },
1048         {
1049                 .ctl_name       = CTL_UNNUMBERED,
1050                 .procname       = "nr_pdflush_threads_min",
1051                 .data           = &nr_pdflush_threads_min,
1052                 .maxlen         = sizeof nr_pdflush_threads_min,
1053                 .mode           = 0644 /* read-write */,
1054                 .proc_handler   = &proc_dointvec_minmax,
1055                 .strategy       = &sysctl_intvec,
1056                 .extra1         = &one,
1057                 .extra2         = &nr_pdflush_threads_max,
1058         },
1059         {
1060                 .ctl_name       = CTL_UNNUMBERED,
1061                 .procname       = "nr_pdflush_threads_max",
1062                 .data           = &nr_pdflush_threads_max,
1063                 .maxlen         = sizeof nr_pdflush_threads_max,
1064                 .mode           = 0644 /* read-write */,
1065                 .proc_handler   = &proc_dointvec_minmax,
1066                 .strategy       = &sysctl_intvec,
1067                 .extra1         = &nr_pdflush_threads_min,
1068                 .extra2         = &one_thousand,
1069         },
1070         {
1071                 .ctl_name       = VM_SWAPPINESS,
1072                 .procname       = "swappiness",
1073                 .data           = &vm_swappiness,
1074                 .maxlen         = sizeof(vm_swappiness),
1075                 .mode           = 0644,
1076                 .proc_handler   = &proc_dointvec_minmax,
1077                 .strategy       = &sysctl_intvec,
1078                 .extra1         = &zero,
1079                 .extra2         = &one_hundred,
1080         },
1081 #ifdef CONFIG_HUGETLB_PAGE
1082          {
1083                 .procname       = "nr_hugepages",
1084                 .data           = NULL,
1085                 .maxlen         = sizeof(unsigned long),
1086                 .mode           = 0644,
1087                 .proc_handler   = &hugetlb_sysctl_handler,
1088                 .extra1         = (void *)&hugetlb_zero,
1089                 .extra2         = (void *)&hugetlb_infinity,
1090          },
1091          {
1092                 .ctl_name       = VM_HUGETLB_GROUP,
1093                 .procname       = "hugetlb_shm_group",
1094                 .data           = &sysctl_hugetlb_shm_group,
1095                 .maxlen         = sizeof(gid_t),
1096                 .mode           = 0644,
1097                 .proc_handler   = &proc_dointvec,
1098          },
1099          {
1100                 .ctl_name       = CTL_UNNUMBERED,
1101                 .procname       = "hugepages_treat_as_movable",
1102                 .data           = &hugepages_treat_as_movable,
1103                 .maxlen         = sizeof(int),
1104                 .mode           = 0644,
1105                 .proc_handler   = &hugetlb_treat_movable_handler,
1106         },
1107         {
1108                 .ctl_name       = CTL_UNNUMBERED,
1109                 .procname       = "nr_overcommit_hugepages",
1110                 .data           = NULL,
1111                 .maxlen         = sizeof(unsigned long),
1112                 .mode           = 0644,
1113                 .proc_handler   = &hugetlb_overcommit_handler,
1114                 .extra1         = (void *)&hugetlb_zero,
1115                 .extra2         = (void *)&hugetlb_infinity,
1116         },
1117 #endif
1118         {
1119                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1120                 .procname       = "lowmem_reserve_ratio",
1121                 .data           = &sysctl_lowmem_reserve_ratio,
1122                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1123                 .mode           = 0644,
1124                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1125                 .strategy       = &sysctl_intvec,
1126         },
1127         {
1128                 .ctl_name       = VM_DROP_PAGECACHE,
1129                 .procname       = "drop_caches",
1130                 .data           = &sysctl_drop_caches,
1131                 .maxlen         = sizeof(int),
1132                 .mode           = 0644,
1133                 .proc_handler   = drop_caches_sysctl_handler,
1134                 .strategy       = &sysctl_intvec,
1135         },
1136         {
1137                 .ctl_name       = VM_MIN_FREE_KBYTES,
1138                 .procname       = "min_free_kbytes",
1139                 .data           = &min_free_kbytes,
1140                 .maxlen         = sizeof(min_free_kbytes),
1141                 .mode           = 0644,
1142                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1143                 .strategy       = &sysctl_intvec,
1144                 .extra1         = &zero,
1145         },
1146         {
1147                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1148                 .procname       = "percpu_pagelist_fraction",
1149                 .data           = &percpu_pagelist_fraction,
1150                 .maxlen         = sizeof(percpu_pagelist_fraction),
1151                 .mode           = 0644,
1152                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1153                 .strategy       = &sysctl_intvec,
1154                 .extra1         = &min_percpu_pagelist_fract,
1155         },
1156 #ifdef CONFIG_MMU
1157         {
1158                 .ctl_name       = VM_MAX_MAP_COUNT,
1159                 .procname       = "max_map_count",
1160                 .data           = &sysctl_max_map_count,
1161                 .maxlen         = sizeof(sysctl_max_map_count),
1162                 .mode           = 0644,
1163                 .proc_handler   = &proc_dointvec
1164         },
1165 #else
1166         {
1167                 .ctl_name       = CTL_UNNUMBERED,
1168                 .procname       = "nr_trim_pages",
1169                 .data           = &sysctl_nr_trim_pages,
1170                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1171                 .mode           = 0644,
1172                 .proc_handler   = &proc_dointvec_minmax,
1173                 .strategy       = &sysctl_intvec,
1174                 .extra1         = &zero,
1175         },
1176 #endif
1177         {
1178                 .ctl_name       = VM_LAPTOP_MODE,
1179                 .procname       = "laptop_mode",
1180                 .data           = &laptop_mode,
1181                 .maxlen         = sizeof(laptop_mode),
1182                 .mode           = 0644,
1183                 .proc_handler   = &proc_dointvec_jiffies,
1184                 .strategy       = &sysctl_jiffies,
1185         },
1186         {
1187                 .ctl_name       = VM_BLOCK_DUMP,
1188                 .procname       = "block_dump",
1189                 .data           = &block_dump,
1190                 .maxlen         = sizeof(block_dump),
1191                 .mode           = 0644,
1192                 .proc_handler   = &proc_dointvec,
1193                 .strategy       = &sysctl_intvec,
1194                 .extra1         = &zero,
1195         },
1196         {
1197                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1198                 .procname       = "vfs_cache_pressure",
1199                 .data           = &sysctl_vfs_cache_pressure,
1200                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1201                 .mode           = 0644,
1202                 .proc_handler   = &proc_dointvec,
1203                 .strategy       = &sysctl_intvec,
1204                 .extra1         = &zero,
1205         },
1206 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1207         {
1208                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1209                 .procname       = "legacy_va_layout",
1210                 .data           = &sysctl_legacy_va_layout,
1211                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1212                 .mode           = 0644,
1213                 .proc_handler   = &proc_dointvec,
1214                 .strategy       = &sysctl_intvec,
1215                 .extra1         = &zero,
1216         },
1217 #endif
1218 #ifdef CONFIG_NUMA
1219         {
1220                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1221                 .procname       = "zone_reclaim_mode",
1222                 .data           = &zone_reclaim_mode,
1223                 .maxlen         = sizeof(zone_reclaim_mode),
1224                 .mode           = 0644,
1225                 .proc_handler   = &proc_dointvec,
1226                 .strategy       = &sysctl_intvec,
1227                 .extra1         = &zero,
1228         },
1229         {
1230                 .ctl_name       = VM_MIN_UNMAPPED,
1231                 .procname       = "min_unmapped_ratio",
1232                 .data           = &sysctl_min_unmapped_ratio,
1233                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1234                 .mode           = 0644,
1235                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1236                 .strategy       = &sysctl_intvec,
1237                 .extra1         = &zero,
1238                 .extra2         = &one_hundred,
1239         },
1240         {
1241                 .ctl_name       = VM_MIN_SLAB,
1242                 .procname       = "min_slab_ratio",
1243                 .data           = &sysctl_min_slab_ratio,
1244                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1245                 .mode           = 0644,
1246                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1247                 .strategy       = &sysctl_intvec,
1248                 .extra1         = &zero,
1249                 .extra2         = &one_hundred,
1250         },
1251 #endif
1252 #ifdef CONFIG_SMP
1253         {
1254                 .ctl_name       = CTL_UNNUMBERED,
1255                 .procname       = "stat_interval",
1256                 .data           = &sysctl_stat_interval,
1257                 .maxlen         = sizeof(sysctl_stat_interval),
1258                 .mode           = 0644,
1259                 .proc_handler   = &proc_dointvec_jiffies,
1260                 .strategy       = &sysctl_jiffies,
1261         },
1262 #endif
1263 #ifdef CONFIG_SECURITY
1264         {
1265                 .ctl_name       = CTL_UNNUMBERED,
1266                 .procname       = "mmap_min_addr",
1267                 .data           = &mmap_min_addr,
1268                 .maxlen         = sizeof(unsigned long),
1269                 .mode           = 0644,
1270                 .proc_handler   = &proc_doulongvec_minmax,
1271         },
1272 #endif
1273 #ifdef CONFIG_NUMA
1274         {
1275                 .ctl_name       = CTL_UNNUMBERED,
1276                 .procname       = "numa_zonelist_order",
1277                 .data           = &numa_zonelist_order,
1278                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1279                 .mode           = 0644,
1280                 .proc_handler   = &numa_zonelist_order_handler,
1281                 .strategy       = &sysctl_string,
1282         },
1283 #endif
1284 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1285    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1286         {
1287                 .ctl_name       = VM_VDSO_ENABLED,
1288                 .procname       = "vdso_enabled",
1289                 .data           = &vdso_enabled,
1290                 .maxlen         = sizeof(vdso_enabled),
1291                 .mode           = 0644,
1292                 .proc_handler   = &proc_dointvec,
1293                 .strategy       = &sysctl_intvec,
1294                 .extra1         = &zero,
1295         },
1296 #endif
1297 #ifdef CONFIG_HIGHMEM
1298         {
1299                 .ctl_name       = CTL_UNNUMBERED,
1300                 .procname       = "highmem_is_dirtyable",
1301                 .data           = &vm_highmem_is_dirtyable,
1302                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1303                 .mode           = 0644,
1304                 .proc_handler   = &proc_dointvec_minmax,
1305                 .strategy       = &sysctl_intvec,
1306                 .extra1         = &zero,
1307                 .extra2         = &one,
1308         },
1309 #endif
1310 #ifdef CONFIG_UNEVICTABLE_LRU
1311         {
1312                 .ctl_name       = CTL_UNNUMBERED,
1313                 .procname       = "scan_unevictable_pages",
1314                 .data           = &scan_unevictable_pages,
1315                 .maxlen         = sizeof(scan_unevictable_pages),
1316                 .mode           = 0644,
1317                 .proc_handler   = &scan_unevictable_handler,
1318         },
1319 #endif
1320 /*
1321  * NOTE: do not add new entries to this table unless you have read
1322  * Documentation/sysctl/ctl_unnumbered.txt
1323  */
1324         { .ctl_name = 0 }
1325 };
1326
1327 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1328 static struct ctl_table binfmt_misc_table[] = {
1329         { .ctl_name = 0 }
1330 };
1331 #endif
1332
1333 static struct ctl_table fs_table[] = {
1334         {
1335                 .ctl_name       = FS_NRINODE,
1336                 .procname       = "inode-nr",
1337                 .data           = &inodes_stat,
1338                 .maxlen         = 2*sizeof(int),
1339                 .mode           = 0444,
1340                 .proc_handler   = &proc_dointvec,
1341         },
1342         {
1343                 .ctl_name       = FS_STATINODE,
1344                 .procname       = "inode-state",
1345                 .data           = &inodes_stat,
1346                 .maxlen         = 7*sizeof(int),
1347                 .mode           = 0444,
1348                 .proc_handler   = &proc_dointvec,
1349         },
1350         {
1351                 .procname       = "file-nr",
1352                 .data           = &files_stat,
1353                 .maxlen         = 3*sizeof(int),
1354                 .mode           = 0444,
1355                 .proc_handler   = &proc_nr_files,
1356         },
1357         {
1358                 .ctl_name       = FS_MAXFILE,
1359                 .procname       = "file-max",
1360                 .data           = &files_stat.max_files,
1361                 .maxlen         = sizeof(int),
1362                 .mode           = 0644,
1363                 .proc_handler   = &proc_dointvec,
1364         },
1365         {
1366                 .ctl_name       = CTL_UNNUMBERED,
1367                 .procname       = "nr_open",
1368                 .data           = &sysctl_nr_open,
1369                 .maxlen         = sizeof(int),
1370                 .mode           = 0644,
1371                 .proc_handler   = &proc_dointvec_minmax,
1372                 .extra1         = &sysctl_nr_open_min,
1373                 .extra2         = &sysctl_nr_open_max,
1374         },
1375         {
1376                 .ctl_name       = FS_DENTRY,
1377                 .procname       = "dentry-state",
1378                 .data           = &dentry_stat,
1379                 .maxlen         = 6*sizeof(int),
1380                 .mode           = 0444,
1381                 .proc_handler   = &proc_dointvec,
1382         },
1383         {
1384                 .ctl_name       = FS_OVERFLOWUID,
1385                 .procname       = "overflowuid",
1386                 .data           = &fs_overflowuid,
1387                 .maxlen         = sizeof(int),
1388                 .mode           = 0644,
1389                 .proc_handler   = &proc_dointvec_minmax,
1390                 .strategy       = &sysctl_intvec,
1391                 .extra1         = &minolduid,
1392                 .extra2         = &maxolduid,
1393         },
1394         {
1395                 .ctl_name       = FS_OVERFLOWGID,
1396                 .procname       = "overflowgid",
1397                 .data           = &fs_overflowgid,
1398                 .maxlen         = sizeof(int),
1399                 .mode           = 0644,
1400                 .proc_handler   = &proc_dointvec_minmax,
1401                 .strategy       = &sysctl_intvec,
1402                 .extra1         = &minolduid,
1403                 .extra2         = &maxolduid,
1404         },
1405 #ifdef CONFIG_FILE_LOCKING
1406         {
1407                 .ctl_name       = FS_LEASES,
1408                 .procname       = "leases-enable",
1409                 .data           = &leases_enable,
1410                 .maxlen         = sizeof(int),
1411                 .mode           = 0644,
1412                 .proc_handler   = &proc_dointvec,
1413         },
1414 #endif
1415 #ifdef CONFIG_DNOTIFY
1416         {
1417                 .ctl_name       = FS_DIR_NOTIFY,
1418                 .procname       = "dir-notify-enable",
1419                 .data           = &dir_notify_enable,
1420                 .maxlen         = sizeof(int),
1421                 .mode           = 0644,
1422                 .proc_handler   = &proc_dointvec,
1423         },
1424 #endif
1425 #ifdef CONFIG_MMU
1426 #ifdef CONFIG_FILE_LOCKING
1427         {
1428                 .ctl_name       = FS_LEASE_TIME,
1429                 .procname       = "lease-break-time",
1430                 .data           = &lease_break_time,
1431                 .maxlen         = sizeof(int),
1432                 .mode           = 0644,
1433                 .proc_handler   = &proc_dointvec,
1434         },
1435 #endif
1436 #ifdef CONFIG_AIO
1437         {
1438                 .procname       = "aio-nr",
1439                 .data           = &aio_nr,
1440                 .maxlen         = sizeof(aio_nr),
1441                 .mode           = 0444,
1442                 .proc_handler   = &proc_doulongvec_minmax,
1443         },
1444         {
1445                 .procname       = "aio-max-nr",
1446                 .data           = &aio_max_nr,
1447                 .maxlen         = sizeof(aio_max_nr),
1448                 .mode           = 0644,
1449                 .proc_handler   = &proc_doulongvec_minmax,
1450         },
1451 #endif /* CONFIG_AIO */
1452 #ifdef CONFIG_INOTIFY_USER
1453         {
1454                 .ctl_name       = FS_INOTIFY,
1455                 .procname       = "inotify",
1456                 .mode           = 0555,
1457                 .child          = inotify_table,
1458         },
1459 #endif
1460 #ifdef CONFIG_EPOLL
1461         {
1462                 .procname       = "epoll",
1463                 .mode           = 0555,
1464                 .child          = epoll_table,
1465         },
1466 #endif
1467 #endif
1468         {
1469                 .ctl_name       = KERN_SETUID_DUMPABLE,
1470                 .procname       = "suid_dumpable",
1471                 .data           = &suid_dumpable,
1472                 .maxlen         = sizeof(int),
1473                 .mode           = 0644,
1474                 .proc_handler   = &proc_dointvec_minmax,
1475                 .strategy       = &sysctl_intvec,
1476                 .extra1         = &zero,
1477                 .extra2         = &two,
1478         },
1479 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1480         {
1481                 .ctl_name       = CTL_UNNUMBERED,
1482                 .procname       = "binfmt_misc",
1483                 .mode           = 0555,
1484                 .child          = binfmt_misc_table,
1485         },
1486 #endif
1487 /*
1488  * NOTE: do not add new entries to this table unless you have read
1489  * Documentation/sysctl/ctl_unnumbered.txt
1490  */
1491         { .ctl_name = 0 }
1492 };
1493
1494 static struct ctl_table debug_table[] = {
1495 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1496         {
1497                 .ctl_name       = CTL_UNNUMBERED,
1498                 .procname       = "exception-trace",
1499                 .data           = &show_unhandled_signals,
1500                 .maxlen         = sizeof(int),
1501                 .mode           = 0644,
1502                 .proc_handler   = proc_dointvec
1503         },
1504 #endif
1505         { .ctl_name = 0 }
1506 };
1507
1508 static struct ctl_table dev_table[] = {
1509         { .ctl_name = 0 }
1510 };
1511
1512 static DEFINE_SPINLOCK(sysctl_lock);
1513
1514 /* called under sysctl_lock */
1515 static int use_table(struct ctl_table_header *p)
1516 {
1517         if (unlikely(p->unregistering))
1518                 return 0;
1519         p->used++;
1520         return 1;
1521 }
1522
1523 /* called under sysctl_lock */
1524 static void unuse_table(struct ctl_table_header *p)
1525 {
1526         if (!--p->used)
1527                 if (unlikely(p->unregistering))
1528                         complete(p->unregistering);
1529 }
1530
1531 /* called under sysctl_lock, will reacquire if has to wait */
1532 static void start_unregistering(struct ctl_table_header *p)
1533 {
1534         /*
1535          * if p->used is 0, nobody will ever touch that entry again;
1536          * we'll eliminate all paths to it before dropping sysctl_lock
1537          */
1538         if (unlikely(p->used)) {
1539                 struct completion wait;
1540                 init_completion(&wait);
1541                 p->unregistering = &wait;
1542                 spin_unlock(&sysctl_lock);
1543                 wait_for_completion(&wait);
1544                 spin_lock(&sysctl_lock);
1545         } else {
1546                 /* anything non-NULL; we'll never dereference it */
1547                 p->unregistering = ERR_PTR(-EINVAL);
1548         }
1549         /*
1550          * do not remove from the list until nobody holds it; walking the
1551          * list in do_sysctl() relies on that.
1552          */
1553         list_del_init(&p->ctl_entry);
1554 }
1555
1556 void sysctl_head_get(struct ctl_table_header *head)
1557 {
1558         spin_lock(&sysctl_lock);
1559         head->count++;
1560         spin_unlock(&sysctl_lock);
1561 }
1562
1563 void sysctl_head_put(struct ctl_table_header *head)
1564 {
1565         spin_lock(&sysctl_lock);
1566         if (!--head->count)
1567                 kfree(head);
1568         spin_unlock(&sysctl_lock);
1569 }
1570
1571 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1572 {
1573         if (!head)
1574                 BUG();
1575         spin_lock(&sysctl_lock);
1576         if (!use_table(head))
1577                 head = ERR_PTR(-ENOENT);
1578         spin_unlock(&sysctl_lock);
1579         return head;
1580 }
1581
1582 void sysctl_head_finish(struct ctl_table_header *head)
1583 {
1584         if (!head)
1585                 return;
1586         spin_lock(&sysctl_lock);
1587         unuse_table(head);
1588         spin_unlock(&sysctl_lock);
1589 }
1590
1591 static struct ctl_table_set *
1592 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1593 {
1594         struct ctl_table_set *set = &root->default_set;
1595         if (root->lookup)
1596                 set = root->lookup(root, namespaces);
1597         return set;
1598 }
1599
1600 static struct list_head *
1601 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1602 {
1603         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1604         return &set->list;
1605 }
1606
1607 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1608                                             struct ctl_table_header *prev)
1609 {
1610         struct ctl_table_root *root;
1611         struct list_head *header_list;
1612         struct ctl_table_header *head;
1613         struct list_head *tmp;
1614
1615         spin_lock(&sysctl_lock);
1616         if (prev) {
1617                 head = prev;
1618                 tmp = &prev->ctl_entry;
1619                 unuse_table(prev);
1620                 goto next;
1621         }
1622         tmp = &root_table_header.ctl_entry;
1623         for (;;) {
1624                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1625
1626                 if (!use_table(head))
1627                         goto next;
1628                 spin_unlock(&sysctl_lock);
1629                 return head;
1630         next:
1631                 root = head->root;
1632                 tmp = tmp->next;
1633                 header_list = lookup_header_list(root, namespaces);
1634                 if (tmp != header_list)
1635                         continue;
1636
1637                 do {
1638                         root = list_entry(root->root_list.next,
1639                                         struct ctl_table_root, root_list);
1640                         if (root == &sysctl_table_root)
1641                                 goto out;
1642                         header_list = lookup_header_list(root, namespaces);
1643                 } while (list_empty(header_list));
1644                 tmp = header_list->next;
1645         }
1646 out:
1647         spin_unlock(&sysctl_lock);
1648         return NULL;
1649 }
1650
1651 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1652 {
1653         return __sysctl_head_next(current->nsproxy, prev);
1654 }
1655
1656 void register_sysctl_root(struct ctl_table_root *root)
1657 {
1658         spin_lock(&sysctl_lock);
1659         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1660         spin_unlock(&sysctl_lock);
1661 }
1662
1663 #ifdef CONFIG_SYSCTL_SYSCALL
1664 /* Perform the actual read/write of a sysctl table entry. */
1665 static int do_sysctl_strategy(struct ctl_table_root *root,
1666                         struct ctl_table *table,
1667                         void __user *oldval, size_t __user *oldlenp,
1668                         void __user *newval, size_t newlen)
1669 {
1670         int op = 0, rc;
1671
1672         if (oldval)
1673                 op |= MAY_READ;
1674         if (newval)
1675                 op |= MAY_WRITE;
1676         if (sysctl_perm(root, table, op))
1677                 return -EPERM;
1678
1679         if (table->strategy) {
1680                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1681                 if (rc < 0)
1682                         return rc;
1683                 if (rc > 0)
1684                         return 0;
1685         }
1686
1687         /* If there is no strategy routine, or if the strategy returns
1688          * zero, proceed with automatic r/w */
1689         if (table->data && table->maxlen) {
1690                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1691                 if (rc < 0)
1692                         return rc;
1693         }
1694         return 0;
1695 }
1696
1697 static int parse_table(int __user *name, int nlen,
1698                        void __user *oldval, size_t __user *oldlenp,
1699                        void __user *newval, size_t newlen,
1700                        struct ctl_table_root *root,
1701                        struct ctl_table *table)
1702 {
1703         int n;
1704 repeat:
1705         if (!nlen)
1706                 return -ENOTDIR;
1707         if (get_user(n, name))
1708                 return -EFAULT;
1709         for ( ; table->ctl_name || table->procname; table++) {
1710                 if (!table->ctl_name)
1711                         continue;
1712                 if (n == table->ctl_name) {
1713                         int error;
1714                         if (table->child) {
1715                                 if (sysctl_perm(root, table, MAY_EXEC))
1716                                         return -EPERM;
1717                                 name++;
1718                                 nlen--;
1719                                 table = table->child;
1720                                 goto repeat;
1721                         }
1722                         error = do_sysctl_strategy(root, table,
1723                                                    oldval, oldlenp,
1724                                                    newval, newlen);
1725                         return error;
1726                 }
1727         }
1728         return -ENOTDIR;
1729 }
1730
1731 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1732                void __user *newval, size_t newlen)
1733 {
1734         struct ctl_table_header *head;
1735         int error = -ENOTDIR;
1736
1737         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1738                 return -ENOTDIR;
1739         if (oldval) {
1740                 int old_len;
1741                 if (!oldlenp || get_user(old_len, oldlenp))
1742                         return -EFAULT;
1743         }
1744
1745         for (head = sysctl_head_next(NULL); head;
1746                         head = sysctl_head_next(head)) {
1747                 error = parse_table(name, nlen, oldval, oldlenp,
1748                                         newval, newlen,
1749                                         head->root, head->ctl_table);
1750                 if (error != -ENOTDIR) {
1751                         sysctl_head_finish(head);
1752                         break;
1753                 }
1754         }
1755         return error;
1756 }
1757
1758 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1759 {
1760         struct __sysctl_args tmp;
1761         int error;
1762
1763         if (copy_from_user(&tmp, args, sizeof(tmp)))
1764                 return -EFAULT;
1765
1766         error = deprecated_sysctl_warning(&tmp);
1767         if (error)
1768                 goto out;
1769
1770         lock_kernel();
1771         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1772                           tmp.newval, tmp.newlen);
1773         unlock_kernel();
1774 out:
1775         return error;
1776 }
1777 #endif /* CONFIG_SYSCTL_SYSCALL */
1778
1779 /*
1780  * sysctl_perm does NOT grant the superuser all rights automatically, because
1781  * some sysctl variables are readonly even to root.
1782  */
1783
1784 static int test_perm(int mode, int op)
1785 {
1786         if (!current_euid())
1787                 mode >>= 6;
1788         else if (in_egroup_p(0))
1789                 mode >>= 3;
1790         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1791                 return 0;
1792         return -EACCES;
1793 }
1794
1795 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1796 {
1797         int error;
1798         int mode;
1799
1800         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1801         if (error)
1802                 return error;
1803
1804         if (root->permissions)
1805                 mode = root->permissions(root, current->nsproxy, table);
1806         else
1807                 mode = table->mode;
1808
1809         return test_perm(mode, op);
1810 }
1811
1812 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1813 {
1814         for (; table->ctl_name || table->procname; table++) {
1815                 table->parent = parent;
1816                 if (table->child)
1817                         sysctl_set_parent(table, table->child);
1818         }
1819 }
1820
1821 static __init int sysctl_init(void)
1822 {
1823         sysctl_set_parent(NULL, root_table);
1824 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1825         {
1826                 int err;
1827                 err = sysctl_check_table(current->nsproxy, root_table);
1828         }
1829 #endif
1830         return 0;
1831 }
1832
1833 core_initcall(sysctl_init);
1834
1835 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1836                                       struct ctl_table *table)
1837 {
1838         struct ctl_table *p;
1839         const char *s = branch->procname;
1840
1841         /* branch should have named subdirectory as its first element */
1842         if (!s || !branch->child)
1843                 return NULL;
1844
1845         /* ... and nothing else */
1846         if (branch[1].procname || branch[1].ctl_name)
1847                 return NULL;
1848
1849         /* table should contain subdirectory with the same name */
1850         for (p = table; p->procname || p->ctl_name; p++) {
1851                 if (!p->child)
1852                         continue;
1853                 if (p->procname && strcmp(p->procname, s) == 0)
1854                         return p;
1855         }
1856         return NULL;
1857 }
1858
1859 /* see if attaching q to p would be an improvement */
1860 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1861 {
1862         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1863         struct ctl_table *next;
1864         int is_better = 0;
1865         int not_in_parent = !p->attached_by;
1866
1867         while ((next = is_branch_in(by, to)) != NULL) {
1868                 if (by == q->attached_by)
1869                         is_better = 1;
1870                 if (to == p->attached_by)
1871                         not_in_parent = 1;
1872                 by = by->child;
1873                 to = next->child;
1874         }
1875
1876         if (is_better && not_in_parent) {
1877                 q->attached_by = by;
1878                 q->attached_to = to;
1879                 q->parent = p;
1880         }
1881 }
1882
1883 /**
1884  * __register_sysctl_paths - register a sysctl hierarchy
1885  * @root: List of sysctl headers to register on
1886  * @namespaces: Data to compute which lists of sysctl entries are visible
1887  * @path: The path to the directory the sysctl table is in.
1888  * @table: the top-level table structure
1889  *
1890  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1891  * array. A completely 0 filled entry terminates the table.
1892  *
1893  * The members of the &struct ctl_table structure are used as follows:
1894  *
1895  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1896  *            must be unique within that level of sysctl
1897  *
1898  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1899  *            enter a sysctl file
1900  *
1901  * data - a pointer to data for use by proc_handler
1902  *
1903  * maxlen - the maximum size in bytes of the data
1904  *
1905  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1906  *
1907  * child - a pointer to the child sysctl table if this entry is a directory, or
1908  *         %NULL.
1909  *
1910  * proc_handler - the text handler routine (described below)
1911  *
1912  * strategy - the strategy routine (described below)
1913  *
1914  * de - for internal use by the sysctl routines
1915  *
1916  * extra1, extra2 - extra pointers usable by the proc handler routines
1917  *
1918  * Leaf nodes in the sysctl tree will be represented by a single file
1919  * under /proc; non-leaf nodes will be represented by directories.
1920  *
1921  * sysctl(2) can automatically manage read and write requests through
1922  * the sysctl table.  The data and maxlen fields of the ctl_table
1923  * struct enable minimal validation of the values being written to be
1924  * performed, and the mode field allows minimal authentication.
1925  *
1926  * More sophisticated management can be enabled by the provision of a
1927  * strategy routine with the table entry.  This will be called before
1928  * any automatic read or write of the data is performed.
1929  *
1930  * The strategy routine may return
1931  *
1932  * < 0 - Error occurred (error is passed to user process)
1933  *
1934  * 0   - OK - proceed with automatic read or write.
1935  *
1936  * > 0 - OK - read or write has been done by the strategy routine, so
1937  *       return immediately.
1938  *
1939  * There must be a proc_handler routine for any terminal nodes
1940  * mirrored under /proc/sys (non-terminals are handled by a built-in
1941  * directory handler).  Several default handlers are available to
1942  * cover common cases -
1943  *
1944  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1945  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1946  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1947  *
1948  * It is the handler's job to read the input buffer from user memory
1949  * and process it. The handler should return 0 on success.
1950  *
1951  * This routine returns %NULL on a failure to register, and a pointer
1952  * to the table header on success.
1953  */
1954 struct ctl_table_header *__register_sysctl_paths(
1955         struct ctl_table_root *root,
1956         struct nsproxy *namespaces,
1957         const struct ctl_path *path, struct ctl_table *table)
1958 {
1959         struct ctl_table_header *header;
1960         struct ctl_table *new, **prevp;
1961         unsigned int n, npath;
1962         struct ctl_table_set *set;
1963
1964         /* Count the path components */
1965         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1966                 ;
1967
1968         /*
1969          * For each path component, allocate a 2-element ctl_table array.
1970          * The first array element will be filled with the sysctl entry
1971          * for this, the second will be the sentinel (ctl_name == 0).
1972          *
1973          * We allocate everything in one go so that we don't have to
1974          * worry about freeing additional memory in unregister_sysctl_table.
1975          */
1976         header = kzalloc(sizeof(struct ctl_table_header) +
1977                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1978         if (!header)
1979                 return NULL;
1980
1981         new = (struct ctl_table *) (header + 1);
1982
1983         /* Now connect the dots */
1984         prevp = &header->ctl_table;
1985         for (n = 0; n < npath; ++n, ++path) {
1986                 /* Copy the procname */
1987                 new->procname = path->procname;
1988                 new->ctl_name = path->ctl_name;
1989                 new->mode     = 0555;
1990
1991                 *prevp = new;
1992                 prevp = &new->child;
1993
1994                 new += 2;
1995         }
1996         *prevp = table;
1997         header->ctl_table_arg = table;
1998
1999         INIT_LIST_HEAD(&header->ctl_entry);
2000         header->used = 0;
2001         header->unregistering = NULL;
2002         header->root = root;
2003         sysctl_set_parent(NULL, header->ctl_table);
2004         header->count = 1;
2005 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2006         if (sysctl_check_table(namespaces, header->ctl_table)) {
2007                 kfree(header);
2008                 return NULL;
2009         }
2010 #endif
2011         spin_lock(&sysctl_lock);
2012         header->set = lookup_header_set(root, namespaces);
2013         header->attached_by = header->ctl_table;
2014         header->attached_to = root_table;
2015         header->parent = &root_table_header;
2016         for (set = header->set; set; set = set->parent) {
2017                 struct ctl_table_header *p;
2018                 list_for_each_entry(p, &set->list, ctl_entry) {
2019                         if (p->unregistering)
2020                                 continue;
2021                         try_attach(p, header);
2022                 }
2023         }
2024         header->parent->count++;
2025         list_add_tail(&header->ctl_entry, &header->set->list);
2026         spin_unlock(&sysctl_lock);
2027
2028         return header;
2029 }
2030
2031 /**
2032  * register_sysctl_table_path - register a sysctl table hierarchy
2033  * @path: The path to the directory the sysctl table is in.
2034  * @table: the top-level table structure
2035  *
2036  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2037  * array. A completely 0 filled entry terminates the table.
2038  *
2039  * See __register_sysctl_paths for more details.
2040  */
2041 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2042                                                 struct ctl_table *table)
2043 {
2044         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2045                                         path, table);
2046 }
2047
2048 /**
2049  * register_sysctl_table - register a sysctl table hierarchy
2050  * @table: the top-level table structure
2051  *
2052  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2053  * array. A completely 0 filled entry terminates the table.
2054  *
2055  * See register_sysctl_paths for more details.
2056  */
2057 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2058 {
2059         static const struct ctl_path null_path[] = { {} };
2060
2061         return register_sysctl_paths(null_path, table);
2062 }
2063
2064 /**
2065  * unregister_sysctl_table - unregister a sysctl table hierarchy
2066  * @header: the header returned from register_sysctl_table
2067  *
2068  * Unregisters the sysctl table and all children. proc entries may not
2069  * actually be removed until they are no longer used by anyone.
2070  */
2071 void unregister_sysctl_table(struct ctl_table_header * header)
2072 {
2073         might_sleep();
2074
2075         if (header == NULL)
2076                 return;
2077
2078         spin_lock(&sysctl_lock);
2079         start_unregistering(header);
2080         if (!--header->parent->count) {
2081                 WARN_ON(1);
2082                 kfree(header->parent);
2083         }
2084         if (!--header->count)
2085                 kfree(header);
2086         spin_unlock(&sysctl_lock);
2087 }
2088
2089 int sysctl_is_seen(struct ctl_table_header *p)
2090 {
2091         struct ctl_table_set *set = p->set;
2092         int res;
2093         spin_lock(&sysctl_lock);
2094         if (p->unregistering)
2095                 res = 0;
2096         else if (!set->is_seen)
2097                 res = 1;
2098         else
2099                 res = set->is_seen(set);
2100         spin_unlock(&sysctl_lock);
2101         return res;
2102 }
2103
2104 void setup_sysctl_set(struct ctl_table_set *p,
2105         struct ctl_table_set *parent,
2106         int (*is_seen)(struct ctl_table_set *))
2107 {
2108         INIT_LIST_HEAD(&p->list);
2109         p->parent = parent ? parent : &sysctl_table_root.default_set;
2110         p->is_seen = is_seen;
2111 }
2112
2113 #else /* !CONFIG_SYSCTL */
2114 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2115 {
2116         return NULL;
2117 }
2118
2119 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2120                                                     struct ctl_table *table)
2121 {
2122         return NULL;
2123 }
2124
2125 void unregister_sysctl_table(struct ctl_table_header * table)
2126 {
2127 }
2128
2129 void setup_sysctl_set(struct ctl_table_set *p,
2130         struct ctl_table_set *parent,
2131         int (*is_seen)(struct ctl_table_set *))
2132 {
2133 }
2134
2135 void sysctl_head_put(struct ctl_table_header *head)
2136 {
2137 }
2138
2139 #endif /* CONFIG_SYSCTL */
2140
2141 /*
2142  * /proc/sys support
2143  */
2144
2145 #ifdef CONFIG_PROC_SYSCTL
2146
2147 static int _proc_do_string(void* data, int maxlen, int write,
2148                            struct file *filp, void __user *buffer,
2149                            size_t *lenp, loff_t *ppos)
2150 {
2151         size_t len;
2152         char __user *p;
2153         char c;
2154
2155         if (!data || !maxlen || !*lenp) {
2156                 *lenp = 0;
2157                 return 0;
2158         }
2159
2160         if (write) {
2161                 len = 0;
2162                 p = buffer;
2163                 while (len < *lenp) {
2164                         if (get_user(c, p++))
2165                                 return -EFAULT;
2166                         if (c == 0 || c == '\n')
2167                                 break;
2168                         len++;
2169                 }
2170                 if (len >= maxlen)
2171                         len = maxlen-1;
2172                 if(copy_from_user(data, buffer, len))
2173                         return -EFAULT;
2174                 ((char *) data)[len] = 0;
2175                 *ppos += *lenp;
2176         } else {
2177                 len = strlen(data);
2178                 if (len > maxlen)
2179                         len = maxlen;
2180
2181                 if (*ppos > len) {
2182                         *lenp = 0;
2183                         return 0;
2184                 }
2185
2186                 data += *ppos;
2187                 len  -= *ppos;
2188
2189                 if (len > *lenp)
2190                         len = *lenp;
2191                 if (len)
2192                         if(copy_to_user(buffer, data, len))
2193                                 return -EFAULT;
2194                 if (len < *lenp) {
2195                         if(put_user('\n', ((char __user *) buffer) + len))
2196                                 return -EFAULT;
2197                         len++;
2198                 }
2199                 *lenp = len;
2200                 *ppos += len;
2201         }
2202         return 0;
2203 }
2204
2205 /**
2206  * proc_dostring - read a string sysctl
2207  * @table: the sysctl table
2208  * @write: %TRUE if this is a write to the sysctl file
2209  * @filp: the file structure
2210  * @buffer: the user buffer
2211  * @lenp: the size of the user buffer
2212  * @ppos: file position
2213  *
2214  * Reads/writes a string from/to the user buffer. If the kernel
2215  * buffer provided is not large enough to hold the string, the
2216  * string is truncated. The copied string is %NULL-terminated.
2217  * If the string is being read by the user process, it is copied
2218  * and a newline '\n' is added. It is truncated if the buffer is
2219  * not large enough.
2220  *
2221  * Returns 0 on success.
2222  */
2223 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2224                   void __user *buffer, size_t *lenp, loff_t *ppos)
2225 {
2226         return _proc_do_string(table->data, table->maxlen, write, filp,
2227                                buffer, lenp, ppos);
2228 }
2229
2230
2231 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2232                                  int *valp,
2233                                  int write, void *data)
2234 {
2235         if (write) {
2236                 *valp = *negp ? -*lvalp : *lvalp;
2237         } else {
2238                 int val = *valp;
2239                 if (val < 0) {
2240                         *negp = -1;
2241                         *lvalp = (unsigned long)-val;
2242                 } else {
2243                         *negp = 0;
2244                         *lvalp = (unsigned long)val;
2245                 }
2246         }
2247         return 0;
2248 }
2249
2250 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2251                   int write, struct file *filp, void __user *buffer,
2252                   size_t *lenp, loff_t *ppos,
2253                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2254                               int write, void *data),
2255                   void *data)
2256 {
2257 #define TMPBUFLEN 21
2258         int *i, vleft, first=1, neg, val;
2259         unsigned long lval;
2260         size_t left, len;
2261
2262         char buf[TMPBUFLEN], *p;
2263         char __user *s = buffer;
2264
2265         if (!tbl_data || !table->maxlen || !*lenp ||
2266             (*ppos && !write)) {
2267                 *lenp = 0;
2268                 return 0;
2269         }
2270
2271         i = (int *) tbl_data;
2272         vleft = table->maxlen / sizeof(*i);
2273         left = *lenp;
2274
2275         if (!conv)
2276                 conv = do_proc_dointvec_conv;
2277
2278         for (; left && vleft--; i++, first=0) {
2279                 if (write) {
2280                         while (left) {
2281                                 char c;
2282                                 if (get_user(c, s))
2283                                         return -EFAULT;
2284                                 if (!isspace(c))
2285                                         break;
2286                                 left--;
2287                                 s++;
2288                         }
2289                         if (!left)
2290                                 break;
2291                         neg = 0;
2292                         len = left;
2293                         if (len > sizeof(buf) - 1)
2294                                 len = sizeof(buf) - 1;
2295                         if (copy_from_user(buf, s, len))
2296                                 return -EFAULT;
2297                         buf[len] = 0;
2298                         p = buf;
2299                         if (*p == '-' && left > 1) {
2300                                 neg = 1;
2301                                 p++;
2302                         }
2303                         if (*p < '0' || *p > '9')
2304                                 break;
2305
2306                         lval = simple_strtoul(p, &p, 0);
2307
2308                         len = p-buf;
2309                         if ((len < left) && *p && !isspace(*p))
2310                                 break;
2311                         if (neg)
2312                                 val = -val;
2313                         s += len;
2314                         left -= len;
2315
2316                         if (conv(&neg, &lval, i, 1, data))
2317                                 break;
2318                 } else {
2319                         p = buf;
2320                         if (!first)
2321                                 *p++ = '\t';
2322
2323                         if (conv(&neg, &lval, i, 0, data))
2324                                 break;
2325
2326                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2327                         len = strlen(buf);
2328                         if (len > left)
2329                                 len = left;
2330                         if(copy_to_user(s, buf, len))
2331                                 return -EFAULT;
2332                         left -= len;
2333                         s += len;
2334                 }
2335         }
2336
2337         if (!write && !first && left) {
2338                 if(put_user('\n', s))
2339                         return -EFAULT;
2340                 left--, s++;
2341         }
2342         if (write) {
2343                 while (left) {
2344                         char c;
2345                         if (get_user(c, s++))
2346                                 return -EFAULT;
2347                         if (!isspace(c))
2348                                 break;
2349                         left--;
2350                 }
2351         }
2352         if (write && first)
2353                 return -EINVAL;
2354         *lenp -= left;
2355         *ppos += *lenp;
2356         return 0;
2357 #undef TMPBUFLEN
2358 }
2359
2360 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2361                   void __user *buffer, size_t *lenp, loff_t *ppos,
2362                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2363                               int write, void *data),
2364                   void *data)
2365 {
2366         return __do_proc_dointvec(table->data, table, write, filp,
2367                         buffer, lenp, ppos, conv, data);
2368 }
2369
2370 /**
2371  * proc_dointvec - read a vector of integers
2372  * @table: the sysctl table
2373  * @write: %TRUE if this is a write to the sysctl file
2374  * @filp: the file structure
2375  * @buffer: the user buffer
2376  * @lenp: the size of the user buffer
2377  * @ppos: file position
2378  *
2379  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2380  * values from/to the user buffer, treated as an ASCII string.
2381  *
2382  * Returns 0 on success.
2383  */
2384 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2385                      void __user *buffer, size_t *lenp, loff_t *ppos)
2386 {
2387     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2388                             NULL,NULL);
2389 }
2390
2391 /*
2392  * Taint values can only be increased
2393  * This means we can safely use a temporary.
2394  */
2395 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2396                                void __user *buffer, size_t *lenp, loff_t *ppos)
2397 {
2398         struct ctl_table t;
2399         unsigned long tmptaint = get_taint();
2400         int err;
2401
2402         if (write && !capable(CAP_SYS_ADMIN))
2403                 return -EPERM;
2404
2405         t = *table;
2406         t.data = &tmptaint;
2407         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2408         if (err < 0)
2409                 return err;
2410
2411         if (write) {
2412                 /*
2413                  * Poor man's atomic or. Not worth adding a primitive
2414                  * to everyone's atomic.h for this
2415                  */
2416                 int i;
2417                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2418                         if ((tmptaint >> i) & 1)
2419                                 add_taint(i);
2420                 }
2421         }
2422
2423         return err;
2424 }
2425
2426 struct do_proc_dointvec_minmax_conv_param {
2427         int *min;
2428         int *max;
2429 };
2430
2431 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2432                                         int *valp,
2433                                         int write, void *data)
2434 {
2435         struct do_proc_dointvec_minmax_conv_param *param = data;
2436         if (write) {
2437                 int val = *negp ? -*lvalp : *lvalp;
2438                 if ((param->min && *param->min > val) ||
2439                     (param->max && *param->max < val))
2440                         return -EINVAL;
2441                 *valp = val;
2442         } else {
2443                 int val = *valp;
2444                 if (val < 0) {
2445                         *negp = -1;
2446                         *lvalp = (unsigned long)-val;
2447                 } else {
2448                         *negp = 0;
2449                         *lvalp = (unsigned long)val;
2450                 }
2451         }
2452         return 0;
2453 }
2454
2455 /**
2456  * proc_dointvec_minmax - read a vector of integers with min/max values
2457  * @table: the sysctl table
2458  * @write: %TRUE if this is a write to the sysctl file
2459  * @filp: the file structure
2460  * @buffer: the user buffer
2461  * @lenp: the size of the user buffer
2462  * @ppos: file position
2463  *
2464  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2465  * values from/to the user buffer, treated as an ASCII string.
2466  *
2467  * This routine will ensure the values are within the range specified by
2468  * table->extra1 (min) and table->extra2 (max).
2469  *
2470  * Returns 0 on success.
2471  */
2472 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2473                   void __user *buffer, size_t *lenp, loff_t *ppos)
2474 {
2475         struct do_proc_dointvec_minmax_conv_param param = {
2476                 .min = (int *) table->extra1,
2477                 .max = (int *) table->extra2,
2478         };
2479         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2480                                 do_proc_dointvec_minmax_conv, &param);
2481 }
2482
2483 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2484                                      struct file *filp,
2485                                      void __user *buffer,
2486                                      size_t *lenp, loff_t *ppos,
2487                                      unsigned long convmul,
2488                                      unsigned long convdiv)
2489 {
2490 #define TMPBUFLEN 21
2491         unsigned long *i, *min, *max, val;
2492         int vleft, first=1, neg;
2493         size_t len, left;
2494         char buf[TMPBUFLEN], *p;
2495         char __user *s = buffer;
2496
2497         if (!data || !table->maxlen || !*lenp ||
2498             (*ppos && !write)) {
2499                 *lenp = 0;
2500                 return 0;
2501         }
2502
2503         i = (unsigned long *) data;
2504         min = (unsigned long *) table->extra1;
2505         max = (unsigned long *) table->extra2;
2506         vleft = table->maxlen / sizeof(unsigned long);
2507         left = *lenp;
2508
2509         for (; left && vleft--; i++, min++, max++, first=0) {
2510                 if (write) {
2511                         while (left) {
2512                                 char c;
2513                                 if (get_user(c, s))
2514                                         return -EFAULT;
2515                                 if (!isspace(c))
2516                                         break;
2517                                 left--;
2518                                 s++;
2519                         }
2520                         if (!left)
2521                                 break;
2522                         neg = 0;
2523                         len = left;
2524                         if (len > TMPBUFLEN-1)
2525                                 len = TMPBUFLEN-1;
2526                         if (copy_from_user(buf, s, len))
2527                                 return -EFAULT;
2528                         buf[len] = 0;
2529                         p = buf;
2530                         if (*p == '-' && left > 1) {
2531                                 neg = 1;
2532                                 p++;
2533                         }
2534                         if (*p < '0' || *p > '9')
2535                                 break;
2536                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2537                         len = p-buf;
2538                         if ((len < left) && *p && !isspace(*p))
2539                                 break;
2540                         if (neg)
2541                                 val = -val;
2542                         s += len;
2543                         left -= len;
2544
2545                         if(neg)
2546                                 continue;
2547                         if ((min && val < *min) || (max && val > *max))
2548                                 continue;
2549                         *i = val;
2550                 } else {
2551                         p = buf;
2552                         if (!first)
2553                                 *p++ = '\t';
2554                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2555                         len = strlen(buf);
2556                         if (len > left)
2557                                 len = left;
2558                         if(copy_to_user(s, buf, len))
2559                                 return -EFAULT;
2560                         left -= len;
2561                         s += len;
2562                 }
2563         }
2564
2565         if (!write && !first && left) {
2566                 if(put_user('\n', s))
2567                         return -EFAULT;
2568                 left--, s++;
2569         }
2570         if (write) {
2571                 while (left) {
2572                         char c;
2573                         if (get_user(c, s++))
2574                                 return -EFAULT;
2575                         if (!isspace(c))
2576                                 break;
2577                         left--;
2578                 }
2579         }
2580         if (write && first)
2581                 return -EINVAL;
2582         *lenp -= left;
2583         *ppos += *lenp;
2584         return 0;
2585 #undef TMPBUFLEN
2586 }
2587
2588 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2589                                      struct file *filp,
2590                                      void __user *buffer,
2591                                      size_t *lenp, loff_t *ppos,
2592                                      unsigned long convmul,
2593                                      unsigned long convdiv)
2594 {
2595         return __do_proc_doulongvec_minmax(table->data, table, write,
2596                         filp, buffer, lenp, ppos, convmul, convdiv);
2597 }
2598
2599 /**
2600  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2601  * @table: the sysctl table
2602  * @write: %TRUE if this is a write to the sysctl file
2603  * @filp: the file structure
2604  * @buffer: the user buffer
2605  * @lenp: the size of the user buffer
2606  * @ppos: file position
2607  *
2608  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2609  * values from/to the user buffer, treated as an ASCII string.
2610  *
2611  * This routine will ensure the values are within the range specified by
2612  * table->extra1 (min) and table->extra2 (max).
2613  *
2614  * Returns 0 on success.
2615  */
2616 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2617                            void __user *buffer, size_t *lenp, loff_t *ppos)
2618 {
2619     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2620 }
2621
2622 /**
2623  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2624  * @table: the sysctl table
2625  * @write: %TRUE if this is a write to the sysctl file
2626  * @filp: the file structure
2627  * @buffer: the user buffer
2628  * @lenp: the size of the user buffer
2629  * @ppos: file position
2630  *
2631  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2632  * values from/to the user buffer, treated as an ASCII string. The values
2633  * are treated as milliseconds, and converted to jiffies when they are stored.
2634  *
2635  * This routine will ensure the values are within the range specified by
2636  * table->extra1 (min) and table->extra2 (max).
2637  *
2638  * Returns 0 on success.
2639  */
2640 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2641                                       struct file *filp,
2642                                       void __user *buffer,
2643                                       size_t *lenp, loff_t *ppos)
2644 {
2645     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2646                                      lenp, ppos, HZ, 1000l);
2647 }
2648
2649
2650 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2651                                          int *valp,
2652                                          int write, void *data)
2653 {
2654         if (write) {
2655                 if (*lvalp > LONG_MAX / HZ)
2656                         return 1;
2657                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2658         } else {
2659                 int val = *valp;
2660                 unsigned long lval;
2661                 if (val < 0) {
2662                         *negp = -1;
2663                         lval = (unsigned long)-val;
2664                 } else {
2665                         *negp = 0;
2666                         lval = (unsigned long)val;
2667                 }
2668                 *lvalp = lval / HZ;
2669         }
2670         return 0;
2671 }
2672
2673 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2674                                                 int *valp,
2675                                                 int write, void *data)
2676 {
2677         if (write) {
2678                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2679                         return 1;
2680                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2681         } else {
2682                 int val = *valp;
2683                 unsigned long lval;
2684                 if (val < 0) {
2685                         *negp = -1;
2686                         lval = (unsigned long)-val;
2687                 } else {
2688                         *negp = 0;
2689                         lval = (unsigned long)val;
2690                 }
2691                 *lvalp = jiffies_to_clock_t(lval);
2692         }
2693         return 0;
2694 }
2695
2696 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2697                                             int *valp,
2698                                             int write, void *data)
2699 {
2700         if (write) {
2701                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2702         } else {
2703                 int val = *valp;
2704                 unsigned long lval;
2705                 if (val < 0) {
2706                         *negp = -1;
2707                         lval = (unsigned long)-val;
2708                 } else {
2709                         *negp = 0;
2710                         lval = (unsigned long)val;
2711                 }
2712                 *lvalp = jiffies_to_msecs(lval);
2713         }
2714         return 0;
2715 }
2716
2717 /**
2718  * proc_dointvec_jiffies - read a vector of integers as seconds
2719  * @table: the sysctl table
2720  * @write: %TRUE if this is a write to the sysctl file
2721  * @filp: the file structure
2722  * @buffer: the user buffer
2723  * @lenp: the size of the user buffer
2724  * @ppos: file position
2725  *
2726  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2727  * values from/to the user buffer, treated as an ASCII string.
2728  * The values read are assumed to be in seconds, and are converted into
2729  * jiffies.
2730  *
2731  * Returns 0 on success.
2732  */
2733 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2734                           void __user *buffer, size_t *lenp, loff_t *ppos)
2735 {
2736     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2737                             do_proc_dointvec_jiffies_conv,NULL);
2738 }
2739
2740 /**
2741  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2742  * @table: the sysctl table
2743  * @write: %TRUE if this is a write to the sysctl file
2744  * @filp: the file structure
2745  * @buffer: the user buffer
2746  * @lenp: the size of the user buffer
2747  * @ppos: pointer to the file position
2748  *
2749  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2750  * values from/to the user buffer, treated as an ASCII string.
2751  * The values read are assumed to be in 1/USER_HZ seconds, and
2752  * are converted into jiffies.
2753  *
2754  * Returns 0 on success.
2755  */
2756 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2757                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2758 {
2759     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2760                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2761 }
2762
2763 /**
2764  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2765  * @table: the sysctl table
2766  * @write: %TRUE if this is a write to the sysctl file
2767  * @filp: the file structure
2768  * @buffer: the user buffer
2769  * @lenp: the size of the user buffer
2770  * @ppos: file position
2771  * @ppos: the current position in the file
2772  *
2773  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2774  * values from/to the user buffer, treated as an ASCII string.
2775  * The values read are assumed to be in 1/1000 seconds, and
2776  * are converted into jiffies.
2777  *
2778  * Returns 0 on success.
2779  */
2780 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2781                              void __user *buffer, size_t *lenp, loff_t *ppos)
2782 {
2783         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2784                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2785 }
2786
2787 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2788                            void __user *buffer, size_t *lenp, loff_t *ppos)
2789 {
2790         struct pid *new_pid;
2791         pid_t tmp;
2792         int r;
2793
2794         tmp = pid_vnr(cad_pid);
2795
2796         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2797                                lenp, ppos, NULL, NULL);
2798         if (r || !write)
2799                 return r;
2800
2801         new_pid = find_get_pid(tmp);
2802         if (!new_pid)
2803                 return -ESRCH;
2804
2805         put_pid(xchg(&cad_pid, new_pid));
2806         return 0;
2807 }
2808
2809 #else /* CONFIG_PROC_FS */
2810
2811 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2812                   void __user *buffer, size_t *lenp, loff_t *ppos)
2813 {
2814         return -ENOSYS;
2815 }
2816
2817 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2818                   void __user *buffer, size_t *lenp, loff_t *ppos)
2819 {
2820         return -ENOSYS;
2821 }
2822
2823 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2824                     void __user *buffer, size_t *lenp, loff_t *ppos)
2825 {
2826         return -ENOSYS;
2827 }
2828
2829 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2830                     void __user *buffer, size_t *lenp, loff_t *ppos)
2831 {
2832         return -ENOSYS;
2833 }
2834
2835 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2836                     void __user *buffer, size_t *lenp, loff_t *ppos)
2837 {
2838         return -ENOSYS;
2839 }
2840
2841 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2842                              void __user *buffer, size_t *lenp, loff_t *ppos)
2843 {
2844         return -ENOSYS;
2845 }
2846
2847 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2848                     void __user *buffer, size_t *lenp, loff_t *ppos)
2849 {
2850         return -ENOSYS;
2851 }
2852
2853 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2854                                       struct file *filp,
2855                                       void __user *buffer,
2856                                       size_t *lenp, loff_t *ppos)
2857 {
2858     return -ENOSYS;
2859 }
2860
2861
2862 #endif /* CONFIG_PROC_FS */
2863
2864
2865 #ifdef CONFIG_SYSCTL_SYSCALL
2866 /*
2867  * General sysctl support routines
2868  */
2869
2870 /* The generic sysctl data routine (used if no strategy routine supplied) */
2871 int sysctl_data(struct ctl_table *table,
2872                 void __user *oldval, size_t __user *oldlenp,
2873                 void __user *newval, size_t newlen)
2874 {
2875         size_t len;
2876
2877         /* Get out of I don't have a variable */
2878         if (!table->data || !table->maxlen)
2879                 return -ENOTDIR;
2880
2881         if (oldval && oldlenp) {
2882                 if (get_user(len, oldlenp))
2883                         return -EFAULT;
2884                 if (len) {
2885                         if (len > table->maxlen)
2886                                 len = table->maxlen;
2887                         if (copy_to_user(oldval, table->data, len))
2888                                 return -EFAULT;
2889                         if (put_user(len, oldlenp))
2890                                 return -EFAULT;
2891                 }
2892         }
2893
2894         if (newval && newlen) {
2895                 if (newlen > table->maxlen)
2896                         newlen = table->maxlen;
2897
2898                 if (copy_from_user(table->data, newval, newlen))
2899                         return -EFAULT;
2900         }
2901         return 1;
2902 }
2903
2904 /* The generic string strategy routine: */
2905 int sysctl_string(struct ctl_table *table,
2906                   void __user *oldval, size_t __user *oldlenp,
2907                   void __user *newval, size_t newlen)
2908 {
2909         if (!table->data || !table->maxlen)
2910                 return -ENOTDIR;
2911
2912         if (oldval && oldlenp) {
2913                 size_t bufsize;
2914                 if (get_user(bufsize, oldlenp))
2915                         return -EFAULT;
2916                 if (bufsize) {
2917                         size_t len = strlen(table->data), copied;
2918
2919                         /* This shouldn't trigger for a well-formed sysctl */
2920                         if (len > table->maxlen)
2921                                 len = table->maxlen;
2922
2923                         /* Copy up to a max of bufsize-1 bytes of the string */
2924                         copied = (len >= bufsize) ? bufsize - 1 : len;
2925
2926                         if (copy_to_user(oldval, table->data, copied) ||
2927                             put_user(0, (char __user *)(oldval + copied)))
2928                                 return -EFAULT;
2929                         if (put_user(len, oldlenp))
2930                                 return -EFAULT;
2931                 }
2932         }
2933         if (newval && newlen) {
2934                 size_t len = newlen;
2935                 if (len > table->maxlen)
2936                         len = table->maxlen;
2937                 if(copy_from_user(table->data, newval, len))
2938                         return -EFAULT;
2939                 if (len == table->maxlen)
2940                         len--;
2941                 ((char *) table->data)[len] = 0;
2942         }
2943         return 1;
2944 }
2945
2946 /*
2947  * This function makes sure that all of the integers in the vector
2948  * are between the minimum and maximum values given in the arrays
2949  * table->extra1 and table->extra2, respectively.
2950  */
2951 int sysctl_intvec(struct ctl_table *table,
2952                 void __user *oldval, size_t __user *oldlenp,
2953                 void __user *newval, size_t newlen)
2954 {
2955
2956         if (newval && newlen) {
2957                 int __user *vec = (int __user *) newval;
2958                 int *min = (int *) table->extra1;
2959                 int *max = (int *) table->extra2;
2960                 size_t length;
2961                 int i;
2962
2963                 if (newlen % sizeof(int) != 0)
2964                         return -EINVAL;
2965
2966                 if (!table->extra1 && !table->extra2)
2967                         return 0;
2968
2969                 if (newlen > table->maxlen)
2970                         newlen = table->maxlen;
2971                 length = newlen / sizeof(int);
2972
2973                 for (i = 0; i < length; i++) {
2974                         int value;
2975                         if (get_user(value, vec + i))
2976                                 return -EFAULT;
2977                         if (min && value < min[i])
2978                                 return -EINVAL;
2979                         if (max && value > max[i])
2980                                 return -EINVAL;
2981                 }
2982         }
2983         return 0;
2984 }
2985
2986 /* Strategy function to convert jiffies to seconds */
2987 int sysctl_jiffies(struct ctl_table *table,
2988                 void __user *oldval, size_t __user *oldlenp,
2989                 void __user *newval, size_t newlen)
2990 {
2991         if (oldval && oldlenp) {
2992                 size_t olen;
2993
2994                 if (get_user(olen, oldlenp))
2995                         return -EFAULT;
2996                 if (olen) {
2997                         int val;
2998
2999                         if (olen < sizeof(int))
3000                                 return -EINVAL;
3001
3002                         val = *(int *)(table->data) / HZ;
3003                         if (put_user(val, (int __user *)oldval))
3004                                 return -EFAULT;
3005                         if (put_user(sizeof(int), oldlenp))
3006                                 return -EFAULT;
3007                 }
3008         }
3009         if (newval && newlen) {
3010                 int new;
3011                 if (newlen != sizeof(int))
3012                         return -EINVAL;
3013                 if (get_user(new, (int __user *)newval))
3014                         return -EFAULT;
3015                 *(int *)(table->data) = new*HZ;
3016         }
3017         return 1;
3018 }
3019
3020 /* Strategy function to convert jiffies to seconds */
3021 int sysctl_ms_jiffies(struct ctl_table *table,
3022                 void __user *oldval, size_t __user *oldlenp,
3023                 void __user *newval, size_t newlen)
3024 {
3025         if (oldval && oldlenp) {
3026                 size_t olen;
3027
3028                 if (get_user(olen, oldlenp))
3029                         return -EFAULT;
3030                 if (olen) {
3031                         int val;
3032
3033                         if (olen < sizeof(int))
3034                                 return -EINVAL;
3035
3036                         val = jiffies_to_msecs(*(int *)(table->data));
3037                         if (put_user(val, (int __user *)oldval))
3038                                 return -EFAULT;
3039                         if (put_user(sizeof(int), oldlenp))
3040                                 return -EFAULT;
3041                 }
3042         }
3043         if (newval && newlen) {
3044                 int new;
3045                 if (newlen != sizeof(int))
3046                         return -EINVAL;
3047                 if (get_user(new, (int __user *)newval))
3048                         return -EFAULT;
3049                 *(int *)(table->data) = msecs_to_jiffies(new);
3050         }
3051         return 1;
3052 }
3053
3054
3055
3056 #else /* CONFIG_SYSCTL_SYSCALL */
3057
3058
3059 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3060 {
3061         struct __sysctl_args tmp;
3062         int error;
3063
3064         if (copy_from_user(&tmp, args, sizeof(tmp)))
3065                 return -EFAULT;
3066
3067         error = deprecated_sysctl_warning(&tmp);
3068
3069         /* If no error reading the parameters then just -ENOSYS ... */
3070         if (!error)
3071                 error = -ENOSYS;
3072
3073         return error;
3074 }
3075
3076 int sysctl_data(struct ctl_table *table,
3077                   void __user *oldval, size_t __user *oldlenp,
3078                   void __user *newval, size_t newlen)
3079 {
3080         return -ENOSYS;
3081 }
3082
3083 int sysctl_string(struct ctl_table *table,
3084                   void __user *oldval, size_t __user *oldlenp,
3085                   void __user *newval, size_t newlen)
3086 {
3087         return -ENOSYS;
3088 }
3089
3090 int sysctl_intvec(struct ctl_table *table,
3091                 void __user *oldval, size_t __user *oldlenp,
3092                 void __user *newval, size_t newlen)
3093 {
3094         return -ENOSYS;
3095 }
3096
3097 int sysctl_jiffies(struct ctl_table *table,
3098                 void __user *oldval, size_t __user *oldlenp,
3099                 void __user *newval, size_t newlen)
3100 {
3101         return -ENOSYS;
3102 }
3103
3104 int sysctl_ms_jiffies(struct ctl_table *table,
3105                 void __user *oldval, size_t __user *oldlenp,
3106                 void __user *newval, size_t newlen)
3107 {
3108         return -ENOSYS;
3109 }
3110
3111 #endif /* CONFIG_SYSCTL_SYSCALL */
3112
3113 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3114 {
3115         static int msg_count;
3116         int name[CTL_MAXNAME];
3117         int i;
3118
3119         /* Check args->nlen. */
3120         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3121                 return -ENOTDIR;
3122
3123         /* Read in the sysctl name for better debug message logging */
3124         for (i = 0; i < args->nlen; i++)
3125                 if (get_user(name[i], args->name + i))
3126                         return -EFAULT;
3127
3128         /* Ignore accesses to kernel.version */
3129         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3130                 return 0;
3131
3132         if (msg_count < 5) {
3133                 msg_count++;
3134                 printk(KERN_INFO
3135                         "warning: process `%s' used the deprecated sysctl "
3136                         "system call with ", current->comm);
3137                 for (i = 0; i < args->nlen; i++)
3138                         printk("%d.", name[i]);
3139                 printk("\n");
3140         }
3141         return 0;
3142 }
3143
3144 /*
3145  * No sense putting this after each symbol definition, twice,
3146  * exception granted :-)
3147  */
3148 EXPORT_SYMBOL(proc_dointvec);
3149 EXPORT_SYMBOL(proc_dointvec_jiffies);
3150 EXPORT_SYMBOL(proc_dointvec_minmax);
3151 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3152 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3153 EXPORT_SYMBOL(proc_dostring);
3154 EXPORT_SYMBOL(proc_doulongvec_minmax);
3155 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3156 EXPORT_SYMBOL(register_sysctl_table);
3157 EXPORT_SYMBOL(register_sysctl_paths);
3158 EXPORT_SYMBOL(sysctl_intvec);
3159 EXPORT_SYMBOL(sysctl_jiffies);
3160 EXPORT_SYMBOL(sysctl_ms_jiffies);
3161 EXPORT_SYMBOL(sysctl_string);
3162 EXPORT_SYMBOL(sysctl_data);
3163 EXPORT_SYMBOL(unregister_sysctl_table);