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   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/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
  52 #include <asm/uaccess.h>
  53 #include <asm/processor.h>
  54
  55 #ifdef CONFIG_X86
  56 #include <asm/nmi.h>
  57 #include <asm/stacktrace.h>
  58 #include <asm/io.h>
  59 #endif
  60
  61 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  62
  63 #if defined(CONFIG_SYSCTL)
  64
  65 /* External variables not in a header file. */
  66 extern int C_A_D;
  67 extern int print_fatal_signals;
  68 extern int sysctl_overcommit_memory;
  69 extern int sysctl_overcommit_ratio;
  70 extern int sysctl_panic_on_oom;
  71 extern int sysctl_oom_kill_allocating_task;
  72 extern int sysctl_oom_dump_tasks;
  73 extern int max_threads;
  74 extern int core_uses_pid;
  75 extern int suid_dumpable;
  76 extern char core_pattern[];
  77 extern int pid_max;
  78 extern int min_free_kbytes;
  79 extern int pid_max_min, pid_max_max;
  80 extern int sysctl_drop_caches;
  81 extern int percpu_pagelist_fraction;
  82 extern int compat_log;
  83 extern int latencytop_enabled;
  84 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  85 #ifndef CONFIG_MMU
  86 extern int sysctl_nr_trim_pages;
  87 #endif
  88 #ifdef CONFIG_RCU_TORTURE_TEST
  89 extern int rcutorture_runnable;
  90 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  91
  92 /* Constants used for minimum and  maximum */
  93 #ifdef CONFIG_DETECT_SOFTLOCKUP
  94 static int sixty = 60;
  95 static int neg_one = -1;
  96 #endif
  97
  98 #if defined(CONFIG_MMU) && defined(CONFIG_FILE_LOCKING)
  99 static int two = 2;
 100 #endif
 101
 102 static int zero;
 103 static int one = 1;
 104 static unsigned long one_ul = 1;
 105 static int one_hundred = 100;
 106
 107 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 108 static int maxolduid = 65535;
 109 static int minolduid;
 110 static int min_percpu_pagelist_fract = 8;
 111
 112 static int ngroups_max = NGROUPS_MAX;
 113
 114 #ifdef CONFIG_MODULES
 115 extern char modprobe_path[];
 116 extern int modules_disabled;
 117 #endif
 118 #ifdef CONFIG_CHR_DEV_SG
 119 extern int sg_big_buff;
 120 #endif
 121
 122 #ifdef CONFIG_SPARC
 123 #include <asm/system.h>
 124 #endif
 125
 126 #ifdef CONFIG_SPARC64
 127 extern int sysctl_tsb_ratio;
 128 #endif
 129
 130 #ifdef __hppa__
 131 extern int pwrsw_enabled;
 132 extern int unaligned_enabled;
 133 #endif
 134
 135 #ifdef CONFIG_S390
 136 #ifdef CONFIG_MATHEMU
 137 extern int sysctl_ieee_emulation_warnings;
 138 #endif
 139 extern int sysctl_userprocess_debug;
 140 extern int spin_retry;
 141 #endif
 142
 143 #ifdef CONFIG_BSD_PROCESS_ACCT
 144 extern int acct_parm[];
 145 #endif
 146
 147 #ifdef CONFIG_IA64
 148 extern int no_unaligned_warning;
 149 extern int unaligned_dump_stack;
 150 #endif
 151
 152 #ifdef CONFIG_RT_MUTEXES
 153 extern int max_lock_depth;
 154 #endif
 155
 156 #ifdef CONFIG_PROC_SYSCTL
 157 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 158                   void __user *buffer, size_t *lenp, loff_t *ppos);
 159 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 160                                void __user *buffer, size_t *lenp, loff_t *ppos);
 161 #endif
 162
 163 static struct ctl_table root_table[];
 164 static struct ctl_table_root sysctl_table_root;
 165 static struct ctl_table_header root_table_header = {
 166         .count = 1,
 167         .ctl_table = root_table,
 168         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 169         .root = &sysctl_table_root,
 170         .set = &sysctl_table_root.default_set,
 171 };
 172 static struct ctl_table_root sysctl_table_root = {
 173         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 174         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 175 };
 176
 177 static struct ctl_table kern_table[];
 178 static struct ctl_table vm_table[];
 179 static struct ctl_table fs_table[];
 180 static struct ctl_table debug_table[];
 181 static struct ctl_table dev_table[];
 182 extern struct ctl_table random_table[];
 183 #ifdef CONFIG_INOTIFY_USER
 184 extern struct ctl_table inotify_table[];
 185 #endif
 186 #ifdef CONFIG_EPOLL
 187 extern struct ctl_table epoll_table[];
 188 #endif
 189
 190 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 191 int sysctl_legacy_va_layout;
 192 #endif
 193
 194 extern int prove_locking;
 195 extern int lock_stat;
 196
 197 /* The default sysctl tables: */
 198
 199 static struct ctl_table root_table[] = {
 200         {
 201                 .ctl_name       = CTL_KERN,
 202                 .procname       = "kernel",
 203                 .mode           = 0555,
 204                 .child          = kern_table,
 205         },
 206         {
 207                 .ctl_name       = CTL_VM,
 208                 .procname       = "vm",
 209                 .mode           = 0555,
 210                 .child          = vm_table,
 211         },
 212         {
 213                 .ctl_name       = CTL_FS,
 214                 .procname       = "fs",
 215                 .mode           = 0555,
 216                 .child          = fs_table,
 217         },
 218         {
 219                 .ctl_name       = CTL_DEBUG,
 220                 .procname       = "debug",
 221                 .mode           = 0555,
 222                 .child          = debug_table,
 223         },
 224         {
 225                 .ctl_name       = CTL_DEV,
 226                 .procname       = "dev",
 227                 .mode           = 0555,
 228                 .child          = dev_table,
 229         },
 230 /*
 231  * NOTE: do not add new entries to this table unless you have read
 232  * Documentation/sysctl/ctl_unnumbered.txt
 233  */
 234         { .ctl_name = 0 }
 235 };
 236
 237 #ifdef CONFIG_SCHED_DEBUG
 238 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 239 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 240 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 241 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 242 #endif
 243
 244 static struct ctl_table kern_table[] = {
 245 #ifdef CONFIG_SCHED_DEBUG
 246         {
 247                 .ctl_name       = CTL_UNNUMBERED,
 248                 .procname       = "sched_min_granularity_ns",
 249                 .data           = &sysctl_sched_min_granularity,
 250                 .maxlen         = sizeof(unsigned int),
 251                 .mode           = 0644,
 252                 .proc_handler   = &sched_nr_latency_handler,
 253                 .strategy       = &sysctl_intvec,
 254                 .extra1         = &min_sched_granularity_ns,
 255                 .extra2         = &max_sched_granularity_ns,
 256         },
 257         {
 258                 .ctl_name       = CTL_UNNUMBERED,
 259                 .procname       = "sched_latency_ns",
 260                 .data           = &sysctl_sched_latency,
 261                 .maxlen         = sizeof(unsigned int),
 262                 .mode           = 0644,
 263                 .proc_handler   = &sched_nr_latency_handler,
 264                 .strategy       = &sysctl_intvec,
 265                 .extra1         = &min_sched_granularity_ns,
 266                 .extra2         = &max_sched_granularity_ns,
 267         },
 268         {
 269                 .ctl_name       = CTL_UNNUMBERED,
 270                 .procname       = "sched_wakeup_granularity_ns",
 271                 .data           = &sysctl_sched_wakeup_granularity,
 272                 .maxlen         = sizeof(unsigned int),
 273                 .mode           = 0644,
 274                 .proc_handler   = &proc_dointvec_minmax,
 275                 .strategy       = &sysctl_intvec,
 276                 .extra1         = &min_wakeup_granularity_ns,
 277                 .extra2         = &max_wakeup_granularity_ns,
 278         },
 279         {
 280                 .ctl_name       = CTL_UNNUMBERED,
 281                 .procname       = "sched_shares_ratelimit",
 282                 .data           = &sysctl_sched_shares_ratelimit,
 283                 .maxlen         = sizeof(unsigned int),
 284                 .mode           = 0644,
 285                 .proc_handler   = &proc_dointvec,
 286         },
 287         {
 288                 .ctl_name       = CTL_UNNUMBERED,
 289                 .procname       = "sched_shares_thresh",
 290                 .data           = &sysctl_sched_shares_thresh,
 291                 .maxlen         = sizeof(unsigned int),
 292                 .mode           = 0644,
 293                 .proc_handler   = &proc_dointvec_minmax,
 294                 .strategy       = &sysctl_intvec,
 295                 .extra1         = &zero,
 296         },
 297         {
 298                 .ctl_name       = CTL_UNNUMBERED,
 299                 .procname       = "sched_child_runs_first",
 300                 .data           = &sysctl_sched_child_runs_first,
 301                 .maxlen         = sizeof(unsigned int),
 302                 .mode           = 0644,
 303                 .proc_handler   = &proc_dointvec,
 304         },
 305         {
 306                 .ctl_name       = CTL_UNNUMBERED,
 307                 .procname       = "sched_features",
 308                 .data           = &sysctl_sched_features,
 309                 .maxlen         = sizeof(unsigned int),
 310                 .mode           = 0644,
 311                 .proc_handler   = &proc_dointvec,
 312         },
 313         {
 314                 .ctl_name       = CTL_UNNUMBERED,
 315                 .procname       = "sched_migration_cost",
 316                 .data           = &sysctl_sched_migration_cost,
 317                 .maxlen         = sizeof(unsigned int),
 318                 .mode           = 0644,
 319                 .proc_handler   = &proc_dointvec,
 320         },
 321         {
 322                 .ctl_name       = CTL_UNNUMBERED,
 323                 .procname       = "sched_nr_migrate",
 324                 .data           = &sysctl_sched_nr_migrate,
 325                 .maxlen         = sizeof(unsigned int),
 326                 .mode           = 0644,
 327                 .proc_handler   = &proc_dointvec,
 328         },
 329 #endif
 330         {
 331                 .ctl_name       = CTL_UNNUMBERED,
 332                 .procname       = "sched_rt_period_us",
 333                 .data           = &sysctl_sched_rt_period,
 334                 .maxlen         = sizeof(unsigned int),
 335                 .mode           = 0644,
 336                 .proc_handler   = &sched_rt_handler,
 337         },
 338         {
 339                 .ctl_name       = CTL_UNNUMBERED,
 340                 .procname       = "sched_rt_runtime_us",
 341                 .data           = &sysctl_sched_rt_runtime,
 342                 .maxlen         = sizeof(int),
 343                 .mode           = 0644,
 344                 .proc_handler   = &sched_rt_handler,
 345         },
 346         {
 347                 .ctl_name       = CTL_UNNUMBERED,
 348                 .procname       = "sched_compat_yield",
 349                 .data           = &sysctl_sched_compat_yield,
 350                 .maxlen         = sizeof(unsigned int),
 351                 .mode           = 0644,
 352                 .proc_handler   = &proc_dointvec,
 353         },
 354 #ifdef CONFIG_PROVE_LOCKING
 355         {
 356                 .ctl_name       = CTL_UNNUMBERED,
 357                 .procname       = "prove_locking",
 358                 .data           = &prove_locking,
 359                 .maxlen         = sizeof(int),
 360                 .mode           = 0644,
 361                 .proc_handler   = &proc_dointvec,
 362         },
 363 #endif
 364 #ifdef CONFIG_LOCK_STAT
 365         {
 366                 .ctl_name       = CTL_UNNUMBERED,
 367                 .procname       = "lock_stat",
 368                 .data           = &lock_stat,
 369                 .maxlen         = sizeof(int),
 370                 .mode           = 0644,
 371                 .proc_handler   = &proc_dointvec,
 372         },
 373 #endif
 374         {
 375                 .ctl_name       = KERN_PANIC,
 376                 .procname       = "panic",
 377                 .data           = &panic_timeout,
 378                 .maxlen         = sizeof(int),
 379                 .mode           = 0644,
 380                 .proc_handler   = &proc_dointvec,
 381         },
 382         {
 383                 .ctl_name       = KERN_CORE_USES_PID,
 384                 .procname       = "core_uses_pid",
 385                 .data           = &core_uses_pid,
 386                 .maxlen         = sizeof(int),
 387                 .mode           = 0644,
 388                 .proc_handler   = &proc_dointvec,
 389         },
 390         {
 391                 .ctl_name       = KERN_CORE_PATTERN,
 392                 .procname       = "core_pattern",
 393                 .data           = core_pattern,
 394                 .maxlen         = CORENAME_MAX_SIZE,
 395                 .mode           = 0644,
 396                 .proc_handler   = &proc_dostring,
 397                 .strategy       = &sysctl_string,
 398         },
 399 #ifdef CONFIG_PROC_SYSCTL
 400         {
 401                 .procname       = "tainted",
 402                 .maxlen         = sizeof(long),
 403                 .mode           = 0644,
 404                 .proc_handler   = &proc_taint,
 405         },
 406 #endif
 407 #ifdef CONFIG_LATENCYTOP
 408         {
 409                 .procname       = "latencytop",
 410                 .data           = &latencytop_enabled,
 411                 .maxlen         = sizeof(int),
 412                 .mode           = 0644,
 413                 .proc_handler   = &proc_dointvec,
 414         },
 415 #endif
 416 #ifdef CONFIG_BLK_DEV_INITRD
 417         {
 418                 .ctl_name       = KERN_REALROOTDEV,
 419                 .procname       = "real-root-dev",
 420                 .data           = &real_root_dev,
 421                 .maxlen         = sizeof(int),
 422                 .mode           = 0644,
 423                 .proc_handler   = &proc_dointvec,
 424         },
 425 #endif
 426         {
 427                 .ctl_name       = CTL_UNNUMBERED,
 428                 .procname       = "print-fatal-signals",
 429                 .data           = &print_fatal_signals,
 430                 .maxlen         = sizeof(int),
 431                 .mode           = 0644,
 432                 .proc_handler   = &proc_dointvec,
 433         },
 434 #ifdef CONFIG_SPARC
 435         {
 436                 .ctl_name       = KERN_SPARC_REBOOT,
 437                 .procname       = "reboot-cmd",
 438                 .data           = reboot_command,
 439                 .maxlen         = 256,
 440                 .mode           = 0644,
 441                 .proc_handler   = &proc_dostring,
 442                 .strategy       = &sysctl_string,
 443         },
 444         {
 445                 .ctl_name       = KERN_SPARC_STOP_A,
 446                 .procname       = "stop-a",
 447                 .data           = &stop_a_enabled,
 448                 .maxlen         = sizeof (int),
 449                 .mode           = 0644,
 450                 .proc_handler   = &proc_dointvec,
 451         },
 452         {
 453                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 454                 .procname       = "scons-poweroff",
 455                 .data           = &scons_pwroff,
 456                 .maxlen         = sizeof (int),
 457                 .mode           = 0644,
 458                 .proc_handler   = &proc_dointvec,
 459         },
 460 #endif
 461 #ifdef CONFIG_SPARC64
 462         {
 463                 .ctl_name       = CTL_UNNUMBERED,
 464                 .procname       = "tsb-ratio",
 465                 .data           = &sysctl_tsb_ratio,
 466                 .maxlen         = sizeof (int),
 467                 .mode           = 0644,
 468                 .proc_handler   = &proc_dointvec,
 469         },
 470 #endif
 471 #ifdef __hppa__
 472         {
 473                 .ctl_name       = KERN_HPPA_PWRSW,
 474                 .procname       = "soft-power",
 475                 .data           = &pwrsw_enabled,
 476                 .maxlen         = sizeof (int),
 477                 .mode           = 0644,
 478                 .proc_handler   = &proc_dointvec,
 479         },
 480         {
 481                 .ctl_name       = KERN_HPPA_UNALIGNED,
 482                 .procname       = "unaligned-trap",
 483                 .data           = &unaligned_enabled,
 484                 .maxlen         = sizeof (int),
 485                 .mode           = 0644,
 486                 .proc_handler   = &proc_dointvec,
 487         },
 488 #endif
 489         {
 490                 .ctl_name       = KERN_CTLALTDEL,
 491                 .procname       = "ctrl-alt-del",
 492                 .data           = &C_A_D,
 493                 .maxlen         = sizeof(int),
 494                 .mode           = 0644,
 495                 .proc_handler   = &proc_dointvec,
 496         },
 497 #ifdef CONFIG_FUNCTION_TRACER
 498         {
 499                 .ctl_name       = CTL_UNNUMBERED,
 500                 .procname       = "ftrace_enabled",
 501                 .data           = &ftrace_enabled,
 502                 .maxlen         = sizeof(int),
 503                 .mode           = 0644,
 504                 .proc_handler   = &ftrace_enable_sysctl,
 505         },
 506 #endif
 507 #ifdef CONFIG_STACK_TRACER
 508         {
 509                 .ctl_name       = CTL_UNNUMBERED,
 510                 .procname       = "stack_tracer_enabled",
 511                 .data           = &stack_tracer_enabled,
 512                 .maxlen         = sizeof(int),
 513                 .mode           = 0644,
 514                 .proc_handler   = &stack_trace_sysctl,
 515         },
 516 #endif
 517 #ifdef CONFIG_TRACING
 518         {
 519                 .ctl_name       = CTL_UNNUMBERED,
 520                 .procname       = "ftrace_dump_on_oops",
 521                 .data           = &ftrace_dump_on_oops,
 522                 .maxlen         = sizeof(int),
 523                 .mode           = 0644,
 524                 .proc_handler   = &proc_dointvec,
 525         },
 526 #endif
 527 #ifdef CONFIG_MODULES
 528         {
 529                 .ctl_name       = KERN_MODPROBE,
 530                 .procname       = "modprobe",
 531                 .data           = &modprobe_path,
 532                 .maxlen         = KMOD_PATH_LEN,
 533                 .mode           = 0644,
 534                 .proc_handler   = &proc_dostring,
 535                 .strategy       = &sysctl_string,
 536         },
 537         {
 538                 .ctl_name       = CTL_UNNUMBERED,
 539                 .procname       = "modules_disabled",
 540                 .data           = &modules_disabled,
 541                 .maxlen         = sizeof(int),
 542                 .mode           = 0644,
 543                 /* only handle a transition from default "0" to "1" */
 544                 .proc_handler   = &proc_dointvec_minmax,
 545                 .extra1         = &one,
 546                 .extra2         = &one,
 547         },
 548 #endif
 549 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 550         {
 551                 .ctl_name       = KERN_HOTPLUG,
 552                 .procname       = "hotplug",
 553                 .data           = &uevent_helper,
 554                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 555                 .mode           = 0644,
 556                 .proc_handler   = &proc_dostring,
 557                 .strategy       = &sysctl_string,
 558         },
 559 #endif
 560 #ifdef CONFIG_CHR_DEV_SG
 561         {
 562                 .ctl_name       = KERN_SG_BIG_BUFF,
 563                 .procname       = "sg-big-buff",
 564                 .data           = &sg_big_buff,
 565                 .maxlen         = sizeof (int),
 566                 .mode           = 0444,
 567                 .proc_handler   = &proc_dointvec,
 568         },
 569 #endif
 570 #ifdef CONFIG_BSD_PROCESS_ACCT
 571         {
 572                 .ctl_name       = KERN_ACCT,
 573                 .procname       = "acct",
 574                 .data           = &acct_parm,
 575                 .maxlen         = 3*sizeof(int),
 576                 .mode           = 0644,
 577                 .proc_handler   = &proc_dointvec,
 578         },
 579 #endif
 580 #ifdef CONFIG_MAGIC_SYSRQ
 581         {
 582                 .ctl_name       = KERN_SYSRQ,
 583                 .procname       = "sysrq",
 584                 .data           = &__sysrq_enabled,
 585                 .maxlen         = sizeof (int),
 586                 .mode           = 0644,
 587                 .proc_handler   = &proc_dointvec,
 588         },
 589 #endif
 590 #ifdef CONFIG_PROC_SYSCTL
 591         {
 592                 .procname       = "cad_pid",
 593                 .data           = NULL,
 594                 .maxlen         = sizeof (int),
 595                 .mode           = 0600,
 596                 .proc_handler   = &proc_do_cad_pid,
 597         },
 598 #endif
 599         {
 600                 .ctl_name       = KERN_MAX_THREADS,
 601                 .procname       = "threads-max",
 602                 .data           = &max_threads,
 603                 .maxlen         = sizeof(int),
 604                 .mode           = 0644,
 605                 .proc_handler   = &proc_dointvec,
 606         },
 607         {
 608                 .ctl_name       = KERN_RANDOM,
 609                 .procname       = "random",
 610                 .mode           = 0555,
 611                 .child          = random_table,
 612         },
 613         {
 614                 .ctl_name       = KERN_OVERFLOWUID,
 615                 .procname       = "overflowuid",
 616                 .data           = &overflowuid,
 617                 .maxlen         = sizeof(int),
 618                 .mode           = 0644,
 619                 .proc_handler   = &proc_dointvec_minmax,
 620                 .strategy       = &sysctl_intvec,
 621                 .extra1         = &minolduid,
 622                 .extra2         = &maxolduid,
 623         },
 624         {
 625                 .ctl_name       = KERN_OVERFLOWGID,
 626                 .procname       = "overflowgid",
 627                 .data           = &overflowgid,
 628                 .maxlen         = sizeof(int),
 629                 .mode           = 0644,
 630                 .proc_handler   = &proc_dointvec_minmax,
 631                 .strategy       = &sysctl_intvec,
 632                 .extra1         = &minolduid,
 633                 .extra2         = &maxolduid,
 634         },
 635 #ifdef CONFIG_S390
 636 #ifdef CONFIG_MATHEMU
 637         {
 638                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 639                 .procname       = "ieee_emulation_warnings",
 640                 .data           = &sysctl_ieee_emulation_warnings,
 641                 .maxlen         = sizeof(int),
 642                 .mode           = 0644,
 643                 .proc_handler   = &proc_dointvec,
 644         },
 645 #endif
 646         {
 647                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 648                 .procname       = "userprocess_debug",
 649                 .data           = &sysctl_userprocess_debug,
 650                 .maxlen         = sizeof(int),
 651                 .mode           = 0644,
 652                 .proc_handler   = &proc_dointvec,
 653         },
 654 #endif
 655         {
 656                 .ctl_name       = KERN_PIDMAX,
 657                 .procname       = "pid_max",
 658                 .data           = &pid_max,
 659                 .maxlen         = sizeof (int),
 660                 .mode           = 0644,
 661                 .proc_handler   = &proc_dointvec_minmax,
 662                 .strategy       = sysctl_intvec,
 663                 .extra1         = &pid_max_min,
 664                 .extra2         = &pid_max_max,
 665         },
 666         {
 667                 .ctl_name       = KERN_PANIC_ON_OOPS,
 668                 .procname       = "panic_on_oops",
 669                 .data           = &panic_on_oops,
 670                 .maxlen         = sizeof(int),
 671                 .mode           = 0644,
 672                 .proc_handler   = &proc_dointvec,
 673         },
 674 #if defined CONFIG_PRINTK
 675         {
 676                 .ctl_name       = KERN_PRINTK,
 677                 .procname       = "printk",
 678                 .data           = &console_loglevel,
 679                 .maxlen         = 4*sizeof(int),
 680                 .mode           = 0644,
 681                 .proc_handler   = &proc_dointvec,
 682         },
 683         {
 684                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 685                 .procname       = "printk_ratelimit",
 686                 .data           = &printk_ratelimit_state.interval,
 687                 .maxlen         = sizeof(int),
 688                 .mode           = 0644,
 689                 .proc_handler   = &proc_dointvec_jiffies,
 690                 .strategy       = &sysctl_jiffies,
 691         },
 692         {
 693                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 694                 .procname       = "printk_ratelimit_burst",
 695                 .data           = &printk_ratelimit_state.burst,
 696                 .maxlen         = sizeof(int),
 697                 .mode           = 0644,
 698                 .proc_handler   = &proc_dointvec,
 699         },
 700 #endif
 701         {
 702                 .ctl_name       = KERN_NGROUPS_MAX,
 703                 .procname       = "ngroups_max",
 704                 .data           = &ngroups_max,
 705                 .maxlen         = sizeof (int),
 706                 .mode           = 0444,
 707                 .proc_handler   = &proc_dointvec,
 708         },
 709 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 710         {
 711                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 712                 .procname       = "unknown_nmi_panic",
 713                 .data           = &unknown_nmi_panic,
 714                 .maxlen         = sizeof (int),
 715                 .mode           = 0644,
 716                 .proc_handler   = &proc_dointvec,
 717         },
 718         {
 719                 .procname       = "nmi_watchdog",
 720                 .data           = &nmi_watchdog_enabled,
 721                 .maxlen         = sizeof (int),
 722                 .mode           = 0644,
 723                 .proc_handler   = &proc_nmi_enabled,
 724         },
 725 #endif
 726 #if defined(CONFIG_X86)
 727         {
 728                 .ctl_name       = KERN_PANIC_ON_NMI,
 729                 .procname       = "panic_on_unrecovered_nmi",
 730                 .data           = &panic_on_unrecovered_nmi,
 731                 .maxlen         = sizeof(int),
 732                 .mode           = 0644,
 733                 .proc_handler   = &proc_dointvec,
 734         },
 735         {
 736                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 737                 .procname       = "bootloader_type",
 738                 .data           = &bootloader_type,
 739                 .maxlen         = sizeof (int),
 740                 .mode           = 0444,
 741                 .proc_handler   = &proc_dointvec,
 742         },
 743         {
 744                 .ctl_name       = CTL_UNNUMBERED,
 745                 .procname       = "kstack_depth_to_print",
 746                 .data           = &kstack_depth_to_print,
 747                 .maxlen         = sizeof(int),
 748                 .mode           = 0644,
 749                 .proc_handler   = &proc_dointvec,
 750         },
 751         {
 752                 .ctl_name       = CTL_UNNUMBERED,
 753                 .procname       = "io_delay_type",
 754                 .data           = &io_delay_type,
 755                 .maxlen         = sizeof(int),
 756                 .mode           = 0644,
 757                 .proc_handler   = &proc_dointvec,
 758         },
 759 #endif
 760 #if defined(CONFIG_MMU)
 761         {
 762                 .ctl_name       = KERN_RANDOMIZE,
 763                 .procname       = "randomize_va_space",
 764                 .data           = &randomize_va_space,
 765                 .maxlen         = sizeof(int),
 766                 .mode           = 0644,
 767                 .proc_handler   = &proc_dointvec,
 768         },
 769 #endif
 770 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 771         {
 772                 .ctl_name       = KERN_SPIN_RETRY,
 773                 .procname       = "spin_retry",
 774                 .data           = &spin_retry,
 775                 .maxlen         = sizeof (int),
 776                 .mode           = 0644,
 777                 .proc_handler   = &proc_dointvec,
 778         },
 779 #endif
 780 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 781         {
 782                 .procname       = "acpi_video_flags",
 783                 .data           = &acpi_realmode_flags,
 784                 .maxlen         = sizeof (unsigned long),
 785                 .mode           = 0644,
 786                 .proc_handler   = &proc_doulongvec_minmax,
 787         },
 788 #endif
 789 #ifdef CONFIG_IA64
 790         {
 791                 .ctl_name       = KERN_IA64_UNALIGNED,
 792                 .procname       = "ignore-unaligned-usertrap",
 793                 .data           = &no_unaligned_warning,
 794                 .maxlen         = sizeof (int),
 795                 .mode           = 0644,
 796                 .proc_handler   = &proc_dointvec,
 797         },
 798         {
 799                 .ctl_name       = CTL_UNNUMBERED,
 800                 .procname       = "unaligned-dump-stack",
 801                 .data           = &unaligned_dump_stack,
 802                 .maxlen         = sizeof (int),
 803                 .mode           = 0644,
 804                 .proc_handler   = &proc_dointvec,
 805         },
 806 #endif
 807 #ifdef CONFIG_DETECT_SOFTLOCKUP
 808         {
 809                 .ctl_name       = CTL_UNNUMBERED,
 810                 .procname       = "softlockup_panic",
 811                 .data           = &softlockup_panic,
 812                 .maxlen         = sizeof(int),
 813                 .mode           = 0644,
 814                 .proc_handler   = &proc_dointvec_minmax,
 815                 .strategy       = &sysctl_intvec,
 816                 .extra1         = &zero,
 817                 .extra2         = &one,
 818         },
 819         {
 820                 .ctl_name       = CTL_UNNUMBERED,
 821                 .procname       = "softlockup_thresh",
 822                 .data           = &softlockup_thresh,
 823                 .maxlen         = sizeof(int),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_dosoftlockup_thresh,
 826                 .strategy       = &sysctl_intvec,
 827                 .extra1         = &neg_one,
 828                 .extra2         = &sixty,
 829         },
 830         {
 831                 .ctl_name       = CTL_UNNUMBERED,
 832                 .procname       = "hung_task_check_count",
 833                 .data           = &sysctl_hung_task_check_count,
 834                 .maxlen         = sizeof(unsigned long),
 835                 .mode           = 0644,
 836                 .proc_handler   = &proc_doulongvec_minmax,
 837                 .strategy       = &sysctl_intvec,
 838         },
 839         {
 840                 .ctl_name       = CTL_UNNUMBERED,
 841                 .procname       = "hung_task_timeout_secs",
 842                 .data           = &sysctl_hung_task_timeout_secs,
 843                 .maxlen         = sizeof(unsigned long),
 844                 .mode           = 0644,
 845                 .proc_handler   = &proc_doulongvec_minmax,
 846                 .strategy       = &sysctl_intvec,
 847         },
 848         {
 849                 .ctl_name       = CTL_UNNUMBERED,
 850                 .procname       = "hung_task_warnings",
 851                 .data           = &sysctl_hung_task_warnings,
 852                 .maxlen         = sizeof(unsigned long),
 853                 .mode           = 0644,
 854                 .proc_handler   = &proc_doulongvec_minmax,
 855                 .strategy       = &sysctl_intvec,
 856         },
 857 #endif
 858 #ifdef CONFIG_COMPAT
 859         {
 860                 .ctl_name       = KERN_COMPAT_LOG,
 861                 .procname       = "compat-log",
 862                 .data           = &compat_log,
 863                 .maxlen         = sizeof (int),
 864                 .mode           = 0644,
 865                 .proc_handler   = &proc_dointvec,
 866         },
 867 #endif
 868 #ifdef CONFIG_RT_MUTEXES
 869         {
 870                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 871                 .procname       = "max_lock_depth",
 872                 .data           = &max_lock_depth,
 873                 .maxlen         = sizeof(int),
 874                 .mode           = 0644,
 875                 .proc_handler   = &proc_dointvec,
 876         },
 877 #endif
 878         {
 879                 .ctl_name       = CTL_UNNUMBERED,
 880                 .procname       = "poweroff_cmd",
 881                 .data           = &poweroff_cmd,
 882                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 883                 .mode           = 0644,
 884                 .proc_handler   = &proc_dostring,
 885                 .strategy       = &sysctl_string,
 886         },
 887 #ifdef CONFIG_KEYS
 888         {
 889                 .ctl_name       = CTL_UNNUMBERED,
 890                 .procname       = "keys",
 891                 .mode           = 0555,
 892                 .child          = key_sysctls,
 893         },
 894 #endif
 895 #ifdef CONFIG_RCU_TORTURE_TEST
 896         {
 897                 .ctl_name       = CTL_UNNUMBERED,
 898                 .procname       = "rcutorture_runnable",
 899                 .data           = &rcutorture_runnable,
 900                 .maxlen         = sizeof(int),
 901                 .mode           = 0644,
 902                 .proc_handler   = &proc_dointvec,
 903         },
 904 #endif
 905 #ifdef CONFIG_UNEVICTABLE_LRU
 906         {
 907                 .ctl_name       = CTL_UNNUMBERED,
 908                 .procname       = "scan_unevictable_pages",
 909                 .data           = &scan_unevictable_pages,
 910                 .maxlen         = sizeof(scan_unevictable_pages),
 911                 .mode           = 0644,
 912                 .proc_handler   = &scan_unevictable_handler,
 913         },
 914 #endif
 915 /*
 916  * NOTE: do not add new entries to this table unless you have read
 917  * Documentation/sysctl/ctl_unnumbered.txt
 918  */
 919         { .ctl_name = 0 }
 920 };
 921
 922 static struct ctl_table vm_table[] = {
 923         {
 924                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 925                 .procname       = "overcommit_memory",
 926                 .data           = &sysctl_overcommit_memory,
 927                 .maxlen         = sizeof(sysctl_overcommit_memory),
 928                 .mode           = 0644,
 929                 .proc_handler   = &proc_dointvec,
 930         },
 931         {
 932                 .ctl_name       = VM_PANIC_ON_OOM,
 933                 .procname       = "panic_on_oom",
 934                 .data           = &sysctl_panic_on_oom,
 935                 .maxlen         = sizeof(sysctl_panic_on_oom),
 936                 .mode           = 0644,
 937                 .proc_handler   = &proc_dointvec,
 938         },
 939         {
 940                 .ctl_name       = CTL_UNNUMBERED,
 941                 .procname       = "oom_kill_allocating_task",
 942                 .data           = &sysctl_oom_kill_allocating_task,
 943                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 944                 .mode           = 0644,
 945                 .proc_handler   = &proc_dointvec,
 946         },
 947         {
 948                 .ctl_name       = CTL_UNNUMBERED,
 949                 .procname       = "oom_dump_tasks",
 950                 .data           = &sysctl_oom_dump_tasks,
 951                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 952                 .mode           = 0644,
 953                 .proc_handler   = &proc_dointvec,
 954         },
 955         {
 956                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 957                 .procname       = "overcommit_ratio",
 958                 .data           = &sysctl_overcommit_ratio,
 959                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 960                 .mode           = 0644,
 961                 .proc_handler   = &proc_dointvec,
 962         },
 963         {
 964                 .ctl_name       = VM_PAGE_CLUSTER,
 965                 .procname       = "page-cluster",
 966                 .data           = &page_cluster,
 967                 .maxlen         = sizeof(int),
 968                 .mode           = 0644,
 969                 .proc_handler   = &proc_dointvec,
 970         },
 971         {
 972                 .ctl_name       = VM_DIRTY_BACKGROUND,
 973                 .procname       = "dirty_background_ratio",
 974                 .data           = &dirty_background_ratio,
 975                 .maxlen         = sizeof(dirty_background_ratio),
 976                 .mode           = 0644,
 977                 .proc_handler   = &dirty_background_ratio_handler,
 978                 .strategy       = &sysctl_intvec,
 979                 .extra1         = &zero,
 980                 .extra2         = &one_hundred,
 981         },
 982         {
 983                 .ctl_name       = CTL_UNNUMBERED,
 984                 .procname       = "dirty_background_bytes",
 985                 .data           = &dirty_background_bytes,
 986                 .maxlen         = sizeof(dirty_background_bytes),
 987                 .mode           = 0644,
 988                 .proc_handler   = &dirty_background_bytes_handler,
 989                 .strategy       = &sysctl_intvec,
 990                 .extra1         = &one_ul,
 991         },
 992         {
 993                 .ctl_name       = VM_DIRTY_RATIO,
 994                 .procname       = "dirty_ratio",
 995                 .data           = &vm_dirty_ratio,
 996                 .maxlen         = sizeof(vm_dirty_ratio),
 997                 .mode           = 0644,
 998                 .proc_handler   = &dirty_ratio_handler,
 999                 .strategy       = &sysctl_intvec,
1000                 .extra1         = &zero,
1001                 .extra2         = &one_hundred,
1002         },
1003         {
1004                 .ctl_name       = CTL_UNNUMBERED,
1005                 .procname       = "dirty_bytes",
1006                 .data           = &vm_dirty_bytes,
1007                 .maxlen         = sizeof(vm_dirty_bytes),
1008                 .mode           = 0644,
1009                 .proc_handler   = &dirty_bytes_handler,
1010                 .strategy       = &sysctl_intvec,
1011                 .extra1         = &one_ul,
1012         },
1013         {
1014                 .procname       = "dirty_writeback_centisecs",
1015                 .data           = &dirty_writeback_interval,
1016                 .maxlen         = sizeof(dirty_writeback_interval),
1017                 .mode           = 0644,
1018                 .proc_handler   = &dirty_writeback_centisecs_handler,
1019         },
1020         {
1021                 .procname       = "dirty_expire_centisecs",
1022                 .data           = &dirty_expire_interval,
1023                 .maxlen         = sizeof(dirty_expire_interval),
1024                 .mode           = 0644,
1025                 .proc_handler   = &proc_dointvec_userhz_jiffies,
1026         },
1027         {
1028                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1029                 .procname       = "nr_pdflush_threads",
1030                 .data           = &nr_pdflush_threads,
1031                 .maxlen         = sizeof nr_pdflush_threads,
1032                 .mode           = 0444 /* read-only*/,
1033                 .proc_handler   = &proc_dointvec,
1034         },
1035         {
1036                 .ctl_name       = VM_SWAPPINESS,
1037                 .procname       = "swappiness",
1038                 .data           = &vm_swappiness,
1039                 .maxlen         = sizeof(vm_swappiness),
1040                 .mode           = 0644,
1041                 .proc_handler   = &proc_dointvec_minmax,
1042                 .strategy       = &sysctl_intvec,
1043                 .extra1         = &zero,
1044                 .extra2         = &one_hundred,
1045         },
1046 #ifdef CONFIG_HUGETLB_PAGE
1047          {
1048                 .procname       = "nr_hugepages",
1049                 .data           = NULL,
1050                 .maxlen         = sizeof(unsigned long),
1051                 .mode           = 0644,
1052                 .proc_handler   = &hugetlb_sysctl_handler,
1053                 .extra1         = (void *)&hugetlb_zero,
1054                 .extra2         = (void *)&hugetlb_infinity,
1055          },
1056          {
1057                 .ctl_name       = VM_HUGETLB_GROUP,
1058                 .procname       = "hugetlb_shm_group",
1059                 .data           = &sysctl_hugetlb_shm_group,
1060                 .maxlen         = sizeof(gid_t),
1061                 .mode           = 0644,
1062                 .proc_handler   = &proc_dointvec,
1063          },
1064          {
1065                 .ctl_name       = CTL_UNNUMBERED,
1066                 .procname       = "hugepages_treat_as_movable",
1067                 .data           = &hugepages_treat_as_movable,
1068                 .maxlen         = sizeof(int),
1069                 .mode           = 0644,
1070                 .proc_handler   = &hugetlb_treat_movable_handler,
1071         },
1072         {
1073                 .ctl_name       = CTL_UNNUMBERED,
1074                 .procname       = "nr_overcommit_hugepages",
1075                 .data           = NULL,
1076                 .maxlen         = sizeof(unsigned long),
1077                 .mode           = 0644,
1078                 .proc_handler   = &hugetlb_overcommit_handler,
1079                 .extra1         = (void *)&hugetlb_zero,
1080                 .extra2         = (void *)&hugetlb_infinity,
1081         },
1082 #endif
1083         {
1084                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1085                 .procname       = "lowmem_reserve_ratio",
1086                 .data           = &sysctl_lowmem_reserve_ratio,
1087                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1088                 .mode           = 0644,
1089                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1090                 .strategy       = &sysctl_intvec,
1091         },
1092         {
1093                 .ctl_name       = VM_DROP_PAGECACHE,
1094                 .procname       = "drop_caches",
1095                 .data           = &sysctl_drop_caches,
1096                 .maxlen         = sizeof(int),
1097                 .mode           = 0644,
1098                 .proc_handler   = drop_caches_sysctl_handler,
1099                 .strategy       = &sysctl_intvec,
1100         },
1101         {
1102                 .ctl_name       = VM_MIN_FREE_KBYTES,
1103                 .procname       = "min_free_kbytes",
1104                 .data           = &min_free_kbytes,
1105                 .maxlen         = sizeof(min_free_kbytes),
1106                 .mode           = 0644,
1107                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1108                 .strategy       = &sysctl_intvec,
1109                 .extra1         = &zero,
1110         },
1111         {
1112                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1113                 .procname       = "percpu_pagelist_fraction",
1114                 .data           = &percpu_pagelist_fraction,
1115                 .maxlen         = sizeof(percpu_pagelist_fraction),
1116                 .mode           = 0644,
1117                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1118                 .strategy       = &sysctl_intvec,
1119                 .extra1         = &min_percpu_pagelist_fract,
1120         },
1121 #ifdef CONFIG_MMU
1122         {
1123                 .ctl_name       = VM_MAX_MAP_COUNT,
1124                 .procname       = "max_map_count",
1125                 .data           = &sysctl_max_map_count,
1126                 .maxlen         = sizeof(sysctl_max_map_count),
1127                 .mode           = 0644,
1128                 .proc_handler   = &proc_dointvec
1129         },
1130 #else
1131         {
1132                 .ctl_name       = CTL_UNNUMBERED,
1133                 .procname       = "nr_trim_pages",
1134                 .data           = &sysctl_nr_trim_pages,
1135                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1136                 .mode           = 0644,
1137                 .proc_handler   = &proc_dointvec_minmax,
1138                 .strategy       = &sysctl_intvec,
1139                 .extra1         = &zero,
1140         },
1141 #endif
1142         {
1143                 .ctl_name       = VM_LAPTOP_MODE,
1144                 .procname       = "laptop_mode",
1145                 .data           = &laptop_mode,
1146                 .maxlen         = sizeof(laptop_mode),
1147                 .mode           = 0644,
1148                 .proc_handler   = &proc_dointvec_jiffies,
1149                 .strategy       = &sysctl_jiffies,
1150         },
1151         {
1152                 .ctl_name       = VM_BLOCK_DUMP,
1153                 .procname       = "block_dump",
1154                 .data           = &block_dump,
1155                 .maxlen         = sizeof(block_dump),
1156                 .mode           = 0644,
1157                 .proc_handler   = &proc_dointvec,
1158                 .strategy       = &sysctl_intvec,
1159                 .extra1         = &zero,
1160         },
1161         {
1162                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1163                 .procname       = "vfs_cache_pressure",
1164                 .data           = &sysctl_vfs_cache_pressure,
1165                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1166                 .mode           = 0644,
1167                 .proc_handler   = &proc_dointvec,
1168                 .strategy       = &sysctl_intvec,
1169                 .extra1         = &zero,
1170         },
1171 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1172         {
1173                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1174                 .procname       = "legacy_va_layout",
1175                 .data           = &sysctl_legacy_va_layout,
1176                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1177                 .mode           = 0644,
1178                 .proc_handler   = &proc_dointvec,
1179                 .strategy       = &sysctl_intvec,
1180                 .extra1         = &zero,
1181         },
1182 #endif
1183 #ifdef CONFIG_NUMA
1184         {
1185                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1186                 .procname       = "zone_reclaim_mode",
1187                 .data           = &zone_reclaim_mode,
1188                 .maxlen         = sizeof(zone_reclaim_mode),
1189                 .mode           = 0644,
1190                 .proc_handler   = &proc_dointvec,
1191                 .strategy       = &sysctl_intvec,
1192                 .extra1         = &zero,
1193         },
1194         {
1195                 .ctl_name       = VM_MIN_UNMAPPED,
1196                 .procname       = "min_unmapped_ratio",
1197                 .data           = &sysctl_min_unmapped_ratio,
1198                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1199                 .mode           = 0644,
1200                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1201                 .strategy       = &sysctl_intvec,
1202                 .extra1         = &zero,
1203                 .extra2         = &one_hundred,
1204         },
1205         {
1206                 .ctl_name       = VM_MIN_SLAB,
1207                 .procname       = "min_slab_ratio",
1208                 .data           = &sysctl_min_slab_ratio,
1209                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1210                 .mode           = 0644,
1211                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1212                 .strategy       = &sysctl_intvec,
1213                 .extra1         = &zero,
1214                 .extra2         = &one_hundred,
1215         },
1216 #endif
1217 #ifdef CONFIG_SMP
1218         {
1219                 .ctl_name       = CTL_UNNUMBERED,
1220                 .procname       = "stat_interval",
1221                 .data           = &sysctl_stat_interval,
1222                 .maxlen         = sizeof(sysctl_stat_interval),
1223                 .mode           = 0644,
1224                 .proc_handler   = &proc_dointvec_jiffies,
1225                 .strategy       = &sysctl_jiffies,
1226         },
1227 #endif
1228 #ifdef CONFIG_SECURITY
1229         {
1230                 .ctl_name       = CTL_UNNUMBERED,
1231                 .procname       = "mmap_min_addr",
1232                 .data           = &mmap_min_addr,
1233                 .maxlen         = sizeof(unsigned long),
1234                 .mode           = 0644,
1235                 .proc_handler   = &proc_doulongvec_minmax,
1236         },
1237 #endif
1238 #ifdef CONFIG_NUMA
1239         {
1240                 .ctl_name       = CTL_UNNUMBERED,
1241                 .procname       = "numa_zonelist_order",
1242                 .data           = &numa_zonelist_order,
1243                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1244                 .mode           = 0644,
1245                 .proc_handler   = &numa_zonelist_order_handler,
1246                 .strategy       = &sysctl_string,
1247         },
1248 #endif
1249 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1250    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1251         {
1252                 .ctl_name       = VM_VDSO_ENABLED,
1253                 .procname       = "vdso_enabled",
1254                 .data           = &vdso_enabled,
1255                 .maxlen         = sizeof(vdso_enabled),
1256                 .mode           = 0644,
1257                 .proc_handler   = &proc_dointvec,
1258                 .strategy       = &sysctl_intvec,
1259                 .extra1         = &zero,
1260         },
1261 #endif
1262 #ifdef CONFIG_HIGHMEM
1263         {
1264                 .ctl_name       = CTL_UNNUMBERED,
1265                 .procname       = "highmem_is_dirtyable",
1266                 .data           = &vm_highmem_is_dirtyable,
1267                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1268                 .mode           = 0644,
1269                 .proc_handler   = &proc_dointvec_minmax,
1270                 .strategy       = &sysctl_intvec,
1271                 .extra1         = &zero,
1272                 .extra2         = &one,
1273         },
1274 #endif
1275 /*
1276  * NOTE: do not add new entries to this table unless you have read
1277  * Documentation/sysctl/ctl_unnumbered.txt
1278  */
1279         { .ctl_name = 0 }
1280 };
1281
1282 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1283 static struct ctl_table binfmt_misc_table[] = {
1284         { .ctl_name = 0 }
1285 };
1286 #endif
1287
1288 static struct ctl_table fs_table[] = {
1289         {
1290                 .ctl_name       = FS_NRINODE,
1291                 .procname       = "inode-nr",
1292                 .data           = &inodes_stat,
1293                 .maxlen         = 2*sizeof(int),
1294                 .mode           = 0444,
1295                 .proc_handler   = &proc_dointvec,
1296         },
1297         {
1298                 .ctl_name       = FS_STATINODE,
1299                 .procname       = "inode-state",
1300                 .data           = &inodes_stat,
1301                 .maxlen         = 7*sizeof(int),
1302                 .mode           = 0444,
1303                 .proc_handler   = &proc_dointvec,
1304         },
1305         {
1306                 .procname       = "file-nr",
1307                 .data           = &files_stat,
1308                 .maxlen         = 3*sizeof(int),
1309                 .mode           = 0444,
1310                 .proc_handler   = &proc_nr_files,
1311         },
1312         {
1313                 .ctl_name       = FS_MAXFILE,
1314                 .procname       = "file-max",
1315                 .data           = &files_stat.max_files,
1316                 .maxlen         = sizeof(int),
1317                 .mode           = 0644,
1318                 .proc_handler   = &proc_dointvec,
1319         },
1320         {
1321                 .ctl_name       = CTL_UNNUMBERED,
1322                 .procname       = "nr_open",
1323                 .data           = &sysctl_nr_open,
1324                 .maxlen         = sizeof(int),
1325                 .mode           = 0644,
1326                 .proc_handler   = &proc_dointvec_minmax,
1327                 .extra1         = &sysctl_nr_open_min,
1328                 .extra2         = &sysctl_nr_open_max,
1329         },
1330         {
1331                 .ctl_name       = FS_DENTRY,
1332                 .procname       = "dentry-state",
1333                 .data           = &dentry_stat,
1334                 .maxlen         = 6*sizeof(int),
1335                 .mode           = 0444,
1336                 .proc_handler   = &proc_dointvec,
1337         },
1338         {
1339                 .ctl_name       = FS_OVERFLOWUID,
1340                 .procname       = "overflowuid",
1341                 .data           = &fs_overflowuid,
1342                 .maxlen         = sizeof(int),
1343                 .mode           = 0644,
1344                 .proc_handler   = &proc_dointvec_minmax,
1345                 .strategy       = &sysctl_intvec,
1346                 .extra1         = &minolduid,
1347                 .extra2         = &maxolduid,
1348         },
1349         {
1350                 .ctl_name       = FS_OVERFLOWGID,
1351                 .procname       = "overflowgid",
1352                 .data           = &fs_overflowgid,
1353                 .maxlen         = sizeof(int),
1354                 .mode           = 0644,
1355                 .proc_handler   = &proc_dointvec_minmax,
1356                 .strategy       = &sysctl_intvec,
1357                 .extra1         = &minolduid,
1358                 .extra2         = &maxolduid,
1359         },
1360 #ifdef CONFIG_FILE_LOCKING
1361         {
1362                 .ctl_name       = FS_LEASES,
1363                 .procname       = "leases-enable",
1364                 .data           = &leases_enable,
1365                 .maxlen         = sizeof(int),
1366                 .mode           = 0644,
1367                 .proc_handler   = &proc_dointvec,
1368         },
1369 #endif
1370 #ifdef CONFIG_DNOTIFY
1371         {
1372                 .ctl_name       = FS_DIR_NOTIFY,
1373                 .procname       = "dir-notify-enable",
1374                 .data           = &dir_notify_enable,
1375                 .maxlen         = sizeof(int),
1376                 .mode           = 0644,
1377                 .proc_handler   = &proc_dointvec,
1378         },
1379 #endif
1380 #ifdef CONFIG_MMU
1381 #ifdef CONFIG_FILE_LOCKING
1382         {
1383                 .ctl_name       = FS_LEASE_TIME,
1384                 .procname       = "lease-break-time",
1385                 .data           = &lease_break_time,
1386                 .maxlen         = sizeof(int),
1387                 .mode           = 0644,
1388                 .proc_handler   = &proc_dointvec_minmax,
1389                 .strategy       = &sysctl_intvec,
1390                 .extra1         = &zero,
1391                 .extra2         = &two,
1392         },
1393 #endif
1394 #ifdef CONFIG_AIO
1395         {
1396                 .procname       = "aio-nr",
1397                 .data           = &aio_nr,
1398                 .maxlen         = sizeof(aio_nr),
1399                 .mode           = 0444,
1400                 .proc_handler   = &proc_doulongvec_minmax,
1401         },
1402         {
1403                 .procname       = "aio-max-nr",
1404                 .data           = &aio_max_nr,
1405                 .maxlen         = sizeof(aio_max_nr),
1406                 .mode           = 0644,
1407                 .proc_handler   = &proc_doulongvec_minmax,
1408         },
1409 #endif /* CONFIG_AIO */
1410 #ifdef CONFIG_INOTIFY_USER
1411         {
1412                 .ctl_name       = FS_INOTIFY,
1413                 .procname       = "inotify",
1414                 .mode           = 0555,
1415                 .child          = inotify_table,
1416         },
1417 #endif
1418 #ifdef CONFIG_EPOLL
1419         {
1420                 .procname       = "epoll",
1421                 .mode           = 0555,
1422                 .child          = epoll_table,
1423         },
1424 #endif
1425 #endif
1426         {
1427                 .ctl_name       = KERN_SETUID_DUMPABLE,
1428                 .procname       = "suid_dumpable",
1429                 .data           = &suid_dumpable,
1430                 .maxlen         = sizeof(int),
1431                 .mode           = 0644,
1432                 .proc_handler   = &proc_dointvec,
1433         },
1434 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1435         {
1436                 .ctl_name       = CTL_UNNUMBERED,
1437                 .procname       = "binfmt_misc",
1438                 .mode           = 0555,
1439                 .child          = binfmt_misc_table,
1440         },
1441 #endif
1442 /*
1443  * NOTE: do not add new entries to this table unless you have read
1444  * Documentation/sysctl/ctl_unnumbered.txt
1445  */
1446         { .ctl_name = 0 }
1447 };
1448
1449 static struct ctl_table debug_table[] = {
1450 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1451         {
1452                 .ctl_name       = CTL_UNNUMBERED,
1453                 .procname       = "exception-trace",
1454                 .data           = &show_unhandled_signals,
1455                 .maxlen         = sizeof(int),
1456                 .mode           = 0644,
1457                 .proc_handler   = proc_dointvec
1458         },
1459 #endif
1460         { .ctl_name = 0 }
1461 };
1462
1463 static struct ctl_table dev_table[] = {
1464         { .ctl_name = 0 }
1465 };
1466
1467 static DEFINE_SPINLOCK(sysctl_lock);
1468
1469 /* called under sysctl_lock */
1470 static int use_table(struct ctl_table_header *p)
1471 {
1472         if (unlikely(p->unregistering))
1473                 return 0;
1474         p->used++;
1475         return 1;
1476 }
1477
1478 /* called under sysctl_lock */
1479 static void unuse_table(struct ctl_table_header *p)
1480 {
1481         if (!--p->used)
1482                 if (unlikely(p->unregistering))
1483                         complete(p->unregistering);
1484 }
1485
1486 /* called under sysctl_lock, will reacquire if has to wait */
1487 static void start_unregistering(struct ctl_table_header *p)
1488 {
1489         /*
1490          * if p->used is 0, nobody will ever touch that entry again;
1491          * we'll eliminate all paths to it before dropping sysctl_lock
1492          */
1493         if (unlikely(p->used)) {
1494                 struct completion wait;
1495                 init_completion(&wait);
1496                 p->unregistering = &wait;
1497                 spin_unlock(&sysctl_lock);
1498                 wait_for_completion(&wait);
1499                 spin_lock(&sysctl_lock);
1500         } else {
1501                 /* anything non-NULL; we'll never dereference it */
1502                 p->unregistering = ERR_PTR(-EINVAL);
1503         }
1504         /*
1505          * do not remove from the list until nobody holds it; walking the
1506          * list in do_sysctl() relies on that.
1507          */
1508         list_del_init(&p->ctl_entry);
1509 }
1510
1511 void sysctl_head_get(struct ctl_table_header *head)
1512 {
1513         spin_lock(&sysctl_lock);
1514         head->count++;
1515         spin_unlock(&sysctl_lock);
1516 }
1517
1518 void sysctl_head_put(struct ctl_table_header *head)
1519 {
1520         spin_lock(&sysctl_lock);
1521         if (!--head->count)
1522                 kfree(head);
1523         spin_unlock(&sysctl_lock);
1524 }
1525
1526 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1527 {
1528         if (!head)
1529                 BUG();
1530         spin_lock(&sysctl_lock);
1531         if (!use_table(head))
1532                 head = ERR_PTR(-ENOENT);
1533         spin_unlock(&sysctl_lock);
1534         return head;
1535 }
1536
1537 void sysctl_head_finish(struct ctl_table_header *head)
1538 {
1539         if (!head)
1540                 return;
1541         spin_lock(&sysctl_lock);
1542         unuse_table(head);
1543         spin_unlock(&sysctl_lock);
1544 }
1545
1546 static struct ctl_table_set *
1547 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1548 {
1549         struct ctl_table_set *set = &root->default_set;
1550         if (root->lookup)
1551                 set = root->lookup(root, namespaces);
1552         return set;
1553 }
1554
1555 static struct list_head *
1556 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1557 {
1558         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1559         return &set->list;
1560 }
1561
1562 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1563                                             struct ctl_table_header *prev)
1564 {
1565         struct ctl_table_root *root;
1566         struct list_head *header_list;
1567         struct ctl_table_header *head;
1568         struct list_head *tmp;
1569
1570         spin_lock(&sysctl_lock);
1571         if (prev) {
1572                 head = prev;
1573                 tmp = &prev->ctl_entry;
1574                 unuse_table(prev);
1575                 goto next;
1576         }
1577         tmp = &root_table_header.ctl_entry;
1578         for (;;) {
1579                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1580
1581                 if (!use_table(head))
1582                         goto next;
1583                 spin_unlock(&sysctl_lock);
1584                 return head;
1585         next:
1586                 root = head->root;
1587                 tmp = tmp->next;
1588                 header_list = lookup_header_list(root, namespaces);
1589                 if (tmp != header_list)
1590                         continue;
1591
1592                 do {
1593                         root = list_entry(root->root_list.next,
1594                                         struct ctl_table_root, root_list);
1595                         if (root == &sysctl_table_root)
1596                                 goto out;
1597                         header_list = lookup_header_list(root, namespaces);
1598                 } while (list_empty(header_list));
1599                 tmp = header_list->next;
1600         }
1601 out:
1602         spin_unlock(&sysctl_lock);
1603         return NULL;
1604 }
1605
1606 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1607 {
1608         return __sysctl_head_next(current->nsproxy, prev);
1609 }
1610
1611 void register_sysctl_root(struct ctl_table_root *root)
1612 {
1613         spin_lock(&sysctl_lock);
1614         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1615         spin_unlock(&sysctl_lock);
1616 }
1617
1618 #ifdef CONFIG_SYSCTL_SYSCALL
1619 /* Perform the actual read/write of a sysctl table entry. */
1620 static int do_sysctl_strategy(struct ctl_table_root *root,
1621                         struct ctl_table *table,
1622                         void __user *oldval, size_t __user *oldlenp,
1623                         void __user *newval, size_t newlen)
1624 {
1625         int op = 0, rc;
1626
1627         if (oldval)
1628                 op |= MAY_READ;
1629         if (newval)
1630                 op |= MAY_WRITE;
1631         if (sysctl_perm(root, table, op))
1632                 return -EPERM;
1633
1634         if (table->strategy) {
1635                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1636                 if (rc < 0)
1637                         return rc;
1638                 if (rc > 0)
1639                         return 0;
1640         }
1641
1642         /* If there is no strategy routine, or if the strategy returns
1643          * zero, proceed with automatic r/w */
1644         if (table->data && table->maxlen) {
1645                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1646                 if (rc < 0)
1647                         return rc;
1648         }
1649         return 0;
1650 }
1651
1652 static int parse_table(int __user *name, int nlen,
1653                        void __user *oldval, size_t __user *oldlenp,
1654                        void __user *newval, size_t newlen,
1655                        struct ctl_table_root *root,
1656                        struct ctl_table *table)
1657 {
1658         int n;
1659 repeat:
1660         if (!nlen)
1661                 return -ENOTDIR;
1662         if (get_user(n, name))
1663                 return -EFAULT;
1664         for ( ; table->ctl_name || table->procname; table++) {
1665                 if (!table->ctl_name)
1666                         continue;
1667                 if (n == table->ctl_name) {
1668                         int error;
1669                         if (table->child) {
1670                                 if (sysctl_perm(root, table, MAY_EXEC))
1671                                         return -EPERM;
1672                                 name++;
1673                                 nlen--;
1674                                 table = table->child;
1675                                 goto repeat;
1676                         }
1677                         error = do_sysctl_strategy(root, table,
1678                                                    oldval, oldlenp,
1679                                                    newval, newlen);
1680                         return error;
1681                 }
1682         }
1683         return -ENOTDIR;
1684 }
1685
1686 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1687                void __user *newval, size_t newlen)
1688 {
1689         struct ctl_table_header *head;
1690         int error = -ENOTDIR;
1691
1692         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1693                 return -ENOTDIR;
1694         if (oldval) {
1695                 int old_len;
1696                 if (!oldlenp || get_user(old_len, oldlenp))
1697                         return -EFAULT;
1698         }
1699
1700         for (head = sysctl_head_next(NULL); head;
1701                         head = sysctl_head_next(head)) {
1702                 error = parse_table(name, nlen, oldval, oldlenp,
1703                                         newval, newlen,
1704                                         head->root, head->ctl_table);
1705                 if (error != -ENOTDIR) {
1706                         sysctl_head_finish(head);
1707                         break;
1708                 }
1709         }
1710         return error;
1711 }
1712
1713 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1714 {
1715         struct __sysctl_args tmp;
1716         int error;
1717
1718         if (copy_from_user(&tmp, args, sizeof(tmp)))
1719                 return -EFAULT;
1720
1721         error = deprecated_sysctl_warning(&tmp);
1722         if (error)
1723                 goto out;
1724
1725         lock_kernel();
1726         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1727                           tmp.newval, tmp.newlen);
1728         unlock_kernel();
1729 out:
1730         return error;
1731 }
1732 #endif /* CONFIG_SYSCTL_SYSCALL */
1733
1734 /*
1735  * sysctl_perm does NOT grant the superuser all rights automatically, because
1736  * some sysctl variables are readonly even to root.
1737  */
1738
1739 static int test_perm(int mode, int op)
1740 {
1741         if (!current_euid())
1742                 mode >>= 6;
1743         else if (in_egroup_p(0))
1744                 mode >>= 3;
1745         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1746                 return 0;
1747         return -EACCES;
1748 }
1749
1750 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1751 {
1752         int error;
1753         int mode;
1754
1755         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1756         if (error)
1757                 return error;
1758
1759         if (root->permissions)
1760                 mode = root->permissions(root, current->nsproxy, table);
1761         else
1762                 mode = table->mode;
1763
1764         return test_perm(mode, op);
1765 }
1766
1767 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1768 {
1769         for (; table->ctl_name || table->procname; table++) {
1770                 table->parent = parent;
1771                 if (table->child)
1772                         sysctl_set_parent(table, table->child);
1773         }
1774 }
1775
1776 static __init int sysctl_init(void)
1777 {
1778         sysctl_set_parent(NULL, root_table);
1779 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1780         {
1781                 int err;
1782                 err = sysctl_check_table(current->nsproxy, root_table);
1783         }
1784 #endif
1785         return 0;
1786 }
1787
1788 core_initcall(sysctl_init);
1789
1790 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1791                                       struct ctl_table *table)
1792 {
1793         struct ctl_table *p;
1794         const char *s = branch->procname;
1795
1796         /* branch should have named subdirectory as its first element */
1797         if (!s || !branch->child)
1798                 return NULL;
1799
1800         /* ... and nothing else */
1801         if (branch[1].procname || branch[1].ctl_name)
1802                 return NULL;
1803
1804         /* table should contain subdirectory with the same name */
1805         for (p = table; p->procname || p->ctl_name; p++) {
1806                 if (!p->child)
1807                         continue;
1808                 if (p->procname && strcmp(p->procname, s) == 0)
1809                         return p;
1810         }
1811         return NULL;
1812 }
1813
1814 /* see if attaching q to p would be an improvement */
1815 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1816 {
1817         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1818         struct ctl_table *next;
1819         int is_better = 0;
1820         int not_in_parent = !p->attached_by;
1821
1822         while ((next = is_branch_in(by, to)) != NULL) {
1823                 if (by == q->attached_by)
1824                         is_better = 1;
1825                 if (to == p->attached_by)
1826                         not_in_parent = 1;
1827                 by = by->child;
1828                 to = next->child;
1829         }
1830
1831         if (is_better && not_in_parent) {
1832                 q->attached_by = by;
1833                 q->attached_to = to;
1834                 q->parent = p;
1835         }
1836 }
1837
1838 /**
1839  * __register_sysctl_paths - register a sysctl hierarchy
1840  * @root: List of sysctl headers to register on
1841  * @namespaces: Data to compute which lists of sysctl entries are visible
1842  * @path: The path to the directory the sysctl table is in.
1843  * @table: the top-level table structure
1844  *
1845  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1846  * array. A completely 0 filled entry terminates the table.
1847  *
1848  * The members of the &struct ctl_table structure are used as follows:
1849  *
1850  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1851  *            must be unique within that level of sysctl
1852  *
1853  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1854  *            enter a sysctl file
1855  *
1856  * data - a pointer to data for use by proc_handler
1857  *
1858  * maxlen - the maximum size in bytes of the data
1859  *
1860  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1861  *
1862  * child - a pointer to the child sysctl table if this entry is a directory, or
1863  *         %NULL.
1864  *
1865  * proc_handler - the text handler routine (described below)
1866  *
1867  * strategy - the strategy routine (described below)
1868  *
1869  * de - for internal use by the sysctl routines
1870  *
1871  * extra1, extra2 - extra pointers usable by the proc handler routines
1872  *
1873  * Leaf nodes in the sysctl tree will be represented by a single file
1874  * under /proc; non-leaf nodes will be represented by directories.
1875  *
1876  * sysctl(2) can automatically manage read and write requests through
1877  * the sysctl table.  The data and maxlen fields of the ctl_table
1878  * struct enable minimal validation of the values being written to be
1879  * performed, and the mode field allows minimal authentication.
1880  *
1881  * More sophisticated management can be enabled by the provision of a
1882  * strategy routine with the table entry.  This will be called before
1883  * any automatic read or write of the data is performed.
1884  *
1885  * The strategy routine may return
1886  *
1887  * < 0 - Error occurred (error is passed to user process)
1888  *
1889  * 0   - OK - proceed with automatic read or write.
1890  *
1891  * > 0 - OK - read or write has been done by the strategy routine, so
1892  *       return immediately.
1893  *
1894  * There must be a proc_handler routine for any terminal nodes
1895  * mirrored under /proc/sys (non-terminals are handled by a built-in
1896  * directory handler).  Several default handlers are available to
1897  * cover common cases -
1898  *
1899  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1900  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1901  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1902  *
1903  * It is the handler's job to read the input buffer from user memory
1904  * and process it. The handler should return 0 on success.
1905  *
1906  * This routine returns %NULL on a failure to register, and a pointer
1907  * to the table header on success.
1908  */
1909 struct ctl_table_header *__register_sysctl_paths(
1910         struct ctl_table_root *root,
1911         struct nsproxy *namespaces,
1912         const struct ctl_path *path, struct ctl_table *table)
1913 {
1914         struct ctl_table_header *header;
1915         struct ctl_table *new, **prevp;
1916         unsigned int n, npath;
1917         struct ctl_table_set *set;
1918
1919         /* Count the path components */
1920         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1921                 ;
1922
1923         /*
1924          * For each path component, allocate a 2-element ctl_table array.
1925          * The first array element will be filled with the sysctl entry
1926          * for this, the second will be the sentinel (ctl_name == 0).
1927          *
1928          * We allocate everything in one go so that we don't have to
1929          * worry about freeing additional memory in unregister_sysctl_table.
1930          */
1931         header = kzalloc(sizeof(struct ctl_table_header) +
1932                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1933         if (!header)
1934                 return NULL;
1935
1936         new = (struct ctl_table *) (header + 1);
1937
1938         /* Now connect the dots */
1939         prevp = &header->ctl_table;
1940         for (n = 0; n < npath; ++n, ++path) {
1941                 /* Copy the procname */
1942                 new->procname = path->procname;
1943                 new->ctl_name = path->ctl_name;
1944                 new->mode     = 0555;
1945
1946                 *prevp = new;
1947                 prevp = &new->child;
1948
1949                 new += 2;
1950         }
1951         *prevp = table;
1952         header->ctl_table_arg = table;
1953
1954         INIT_LIST_HEAD(&header->ctl_entry);
1955         header->used = 0;
1956         header->unregistering = NULL;
1957         header->root = root;
1958         sysctl_set_parent(NULL, header->ctl_table);
1959         header->count = 1;
1960 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1961         if (sysctl_check_table(namespaces, header->ctl_table)) {
1962                 kfree(header);
1963                 return NULL;
1964         }
1965 #endif
1966         spin_lock(&sysctl_lock);
1967         header->set = lookup_header_set(root, namespaces);
1968         header->attached_by = header->ctl_table;
1969         header->attached_to = root_table;
1970         header->parent = &root_table_header;
1971         for (set = header->set; set; set = set->parent) {
1972                 struct ctl_table_header *p;
1973                 list_for_each_entry(p, &set->list, ctl_entry) {
1974                         if (p->unregistering)
1975                                 continue;
1976                         try_attach(p, header);
1977                 }
1978         }
1979         header->parent->count++;
1980         list_add_tail(&header->ctl_entry, &header->set->list);
1981         spin_unlock(&sysctl_lock);
1982
1983         return header;
1984 }
1985
1986 /**
1987  * register_sysctl_table_path - register a sysctl table hierarchy
1988  * @path: The path to the directory the sysctl table is in.
1989  * @table: the top-level table structure
1990  *
1991  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1992  * array. A completely 0 filled entry terminates the table.
1993  *
1994  * See __register_sysctl_paths for more details.
1995  */
1996 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1997                                                 struct ctl_table *table)
1998 {
1999         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2000                                         path, table);
2001 }
2002
2003 /**
2004  * register_sysctl_table - register a sysctl table hierarchy
2005  * @table: the top-level table structure
2006  *
2007  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2008  * array. A completely 0 filled entry terminates the table.
2009  *
2010  * See register_sysctl_paths for more details.
2011  */
2012 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2013 {
2014         static const struct ctl_path null_path[] = { {} };
2015
2016         return register_sysctl_paths(null_path, table);
2017 }
2018
2019 /**
2020  * unregister_sysctl_table - unregister a sysctl table hierarchy
2021  * @header: the header returned from register_sysctl_table
2022  *
2023  * Unregisters the sysctl table and all children. proc entries may not
2024  * actually be removed until they are no longer used by anyone.
2025  */
2026 void unregister_sysctl_table(struct ctl_table_header * header)
2027 {
2028         might_sleep();
2029
2030         if (header == NULL)
2031                 return;
2032
2033         spin_lock(&sysctl_lock);
2034         start_unregistering(header);
2035         if (!--header->parent->count) {
2036                 WARN_ON(1);
2037                 kfree(header->parent);
2038         }
2039         if (!--header->count)
2040                 kfree(header);
2041         spin_unlock(&sysctl_lock);
2042 }
2043
2044 int sysctl_is_seen(struct ctl_table_header *p)
2045 {
2046         struct ctl_table_set *set = p->set;
2047         int res;
2048         spin_lock(&sysctl_lock);
2049         if (p->unregistering)
2050                 res = 0;
2051         else if (!set->is_seen)
2052                 res = 1;
2053         else
2054                 res = set->is_seen(set);
2055         spin_unlock(&sysctl_lock);
2056         return res;
2057 }
2058
2059 void setup_sysctl_set(struct ctl_table_set *p,
2060         struct ctl_table_set *parent,
2061         int (*is_seen)(struct ctl_table_set *))
2062 {
2063         INIT_LIST_HEAD(&p->list);
2064         p->parent = parent ? parent : &sysctl_table_root.default_set;
2065         p->is_seen = is_seen;
2066 }
2067
2068 #else /* !CONFIG_SYSCTL */
2069 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2070 {
2071         return NULL;
2072 }
2073
2074 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2075                                                     struct ctl_table *table)
2076 {
2077         return NULL;
2078 }
2079
2080 void unregister_sysctl_table(struct ctl_table_header * table)
2081 {
2082 }
2083
2084 void setup_sysctl_set(struct ctl_table_set *p,
2085         struct ctl_table_set *parent,
2086         int (*is_seen)(struct ctl_table_set *))
2087 {
2088 }
2089
2090 void sysctl_head_put(struct ctl_table_header *head)
2091 {
2092 }
2093
2094 #endif /* CONFIG_SYSCTL */
2095
2096 /*
2097  * /proc/sys support
2098  */
2099
2100 #ifdef CONFIG_PROC_SYSCTL
2101
2102 static int _proc_do_string(void* data, int maxlen, int write,
2103                            struct file *filp, void __user *buffer,
2104                            size_t *lenp, loff_t *ppos)
2105 {
2106         size_t len;
2107         char __user *p;
2108         char c;
2109
2110         if (!data || !maxlen || !*lenp) {
2111                 *lenp = 0;
2112                 return 0;
2113         }
2114
2115         if (write) {
2116                 len = 0;
2117                 p = buffer;
2118                 while (len < *lenp) {
2119                         if (get_user(c, p++))
2120                                 return -EFAULT;
2121                         if (c == 0 || c == '\n')
2122                                 break;
2123                         len++;
2124                 }
2125                 if (len >= maxlen)
2126                         len = maxlen-1;
2127                 if(copy_from_user(data, buffer, len))
2128                         return -EFAULT;
2129                 ((char *) data)[len] = 0;
2130                 *ppos += *lenp;
2131         } else {
2132                 len = strlen(data);
2133                 if (len > maxlen)
2134                         len = maxlen;
2135
2136                 if (*ppos > len) {
2137                         *lenp = 0;
2138                         return 0;
2139                 }
2140
2141                 data += *ppos;
2142                 len  -= *ppos;
2143
2144                 if (len > *lenp)
2145                         len = *lenp;
2146                 if (len)
2147                         if(copy_to_user(buffer, data, len))
2148                                 return -EFAULT;
2149                 if (len < *lenp) {
2150                         if(put_user('\n', ((char __user *) buffer) + len))
2151                                 return -EFAULT;
2152                         len++;
2153                 }
2154                 *lenp = len;
2155                 *ppos += len;
2156         }
2157         return 0;
2158 }
2159
2160 /**
2161  * proc_dostring - read a string sysctl
2162  * @table: the sysctl table
2163  * @write: %TRUE if this is a write to the sysctl file
2164  * @filp: the file structure
2165  * @buffer: the user buffer
2166  * @lenp: the size of the user buffer
2167  * @ppos: file position
2168  *
2169  * Reads/writes a string from/to the user buffer. If the kernel
2170  * buffer provided is not large enough to hold the string, the
2171  * string is truncated. The copied string is %NULL-terminated.
2172  * If the string is being read by the user process, it is copied
2173  * and a newline '\n' is added. It is truncated if the buffer is
2174  * not large enough.
2175  *
2176  * Returns 0 on success.
2177  */
2178 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2179                   void __user *buffer, size_t *lenp, loff_t *ppos)
2180 {
2181         return _proc_do_string(table->data, table->maxlen, write, filp,
2182                                buffer, lenp, ppos);
2183 }
2184
2185
2186 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2187                                  int *valp,
2188                                  int write, void *data)
2189 {
2190         if (write) {
2191                 *valp = *negp ? -*lvalp : *lvalp;
2192         } else {
2193                 int val = *valp;
2194                 if (val < 0) {
2195                         *negp = -1;
2196                         *lvalp = (unsigned long)-val;
2197                 } else {
2198                         *negp = 0;
2199                         *lvalp = (unsigned long)val;
2200                 }
2201         }
2202         return 0;
2203 }
2204
2205 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2206                   int write, struct file *filp, void __user *buffer,
2207                   size_t *lenp, loff_t *ppos,
2208                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2209                               int write, void *data),
2210                   void *data)
2211 {
2212 #define TMPBUFLEN 21
2213         int *i, vleft, first=1, neg, val;
2214         unsigned long lval;
2215         size_t left, len;
2216
2217         char buf[TMPBUFLEN], *p;
2218         char __user *s = buffer;
2219
2220         if (!tbl_data || !table->maxlen || !*lenp ||
2221             (*ppos && !write)) {
2222                 *lenp = 0;
2223                 return 0;
2224         }
2225
2226         i = (int *) tbl_data;
2227         vleft = table->maxlen / sizeof(*i);
2228         left = *lenp;
2229
2230         if (!conv)
2231                 conv = do_proc_dointvec_conv;
2232
2233         for (; left && vleft--; i++, first=0) {
2234                 if (write) {
2235                         while (left) {
2236                                 char c;
2237                                 if (get_user(c, s))
2238                                         return -EFAULT;
2239                                 if (!isspace(c))
2240                                         break;
2241                                 left--;
2242                                 s++;
2243                         }
2244                         if (!left)
2245                                 break;
2246                         neg = 0;
2247                         len = left;
2248                         if (len > sizeof(buf) - 1)
2249                                 len = sizeof(buf) - 1;
2250                         if (copy_from_user(buf, s, len))
2251                                 return -EFAULT;
2252                         buf[len] = 0;
2253                         p = buf;
2254                         if (*p == '-' && left > 1) {
2255                                 neg = 1;
2256                                 p++;
2257                         }
2258                         if (*p < '0' || *p > '9')
2259                                 break;
2260
2261                         lval = simple_strtoul(p, &p, 0);
2262
2263                         len = p-buf;
2264                         if ((len < left) && *p && !isspace(*p))
2265                                 break;
2266                         if (neg)
2267                                 val = -val;
2268                         s += len;
2269                         left -= len;
2270
2271                         if (conv(&neg, &lval, i, 1, data))
2272                                 break;
2273                 } else {
2274                         p = buf;
2275                         if (!first)
2276                                 *p++ = '\t';
2277
2278                         if (conv(&neg, &lval, i, 0, data))
2279                                 break;
2280
2281                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2282                         len = strlen(buf);
2283                         if (len > left)
2284                                 len = left;
2285                         if(copy_to_user(s, buf, len))
2286                                 return -EFAULT;
2287                         left -= len;
2288                         s += len;
2289                 }
2290         }
2291
2292         if (!write && !first && left) {
2293                 if(put_user('\n', s))
2294                         return -EFAULT;
2295                 left--, s++;
2296         }
2297         if (write) {
2298                 while (left) {
2299                         char c;
2300                         if (get_user(c, s++))
2301                                 return -EFAULT;
2302                         if (!isspace(c))
2303                                 break;
2304                         left--;
2305                 }
2306         }
2307         if (write && first)
2308                 return -EINVAL;
2309         *lenp -= left;
2310         *ppos += *lenp;
2311         return 0;
2312 #undef TMPBUFLEN
2313 }
2314
2315 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2316                   void __user *buffer, size_t *lenp, loff_t *ppos,
2317                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2318                               int write, void *data),
2319                   void *data)
2320 {
2321         return __do_proc_dointvec(table->data, table, write, filp,
2322                         buffer, lenp, ppos, conv, data);
2323 }
2324
2325 /**
2326  * proc_dointvec - read a vector of integers
2327  * @table: the sysctl table
2328  * @write: %TRUE if this is a write to the sysctl file
2329  * @filp: the file structure
2330  * @buffer: the user buffer
2331  * @lenp: the size of the user buffer
2332  * @ppos: file position
2333  *
2334  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2335  * values from/to the user buffer, treated as an ASCII string.
2336  *
2337  * Returns 0 on success.
2338  */
2339 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2340                      void __user *buffer, size_t *lenp, loff_t *ppos)
2341 {
2342     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2343                             NULL,NULL);
2344 }
2345
2346 /*
2347  * Taint values can only be increased
2348  * This means we can safely use a temporary.
2349  */
2350 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2351                                void __user *buffer, size_t *lenp, loff_t *ppos)
2352 {
2353         struct ctl_table t;
2354         unsigned long tmptaint = get_taint();
2355         int err;
2356
2357         if (write && !capable(CAP_SYS_ADMIN))
2358                 return -EPERM;
2359
2360         t = *table;
2361         t.data = &tmptaint;
2362         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2363         if (err < 0)
2364                 return err;
2365
2366         if (write) {
2367                 /*
2368                  * Poor man's atomic or. Not worth adding a primitive
2369                  * to everyone's atomic.h for this
2370                  */
2371                 int i;
2372                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2373                         if ((tmptaint >> i) & 1)
2374                                 add_taint(i);
2375                 }
2376         }
2377
2378         return err;
2379 }
2380
2381 struct do_proc_dointvec_minmax_conv_param {
2382         int *min;
2383         int *max;
2384 };
2385
2386 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2387                                         int *valp,
2388                                         int write, void *data)
2389 {
2390         struct do_proc_dointvec_minmax_conv_param *param = data;
2391         if (write) {
2392                 int val = *negp ? -*lvalp : *lvalp;
2393                 if ((param->min && *param->min > val) ||
2394                     (param->max && *param->max < val))
2395                         return -EINVAL;
2396                 *valp = val;
2397         } else {
2398                 int val = *valp;
2399                 if (val < 0) {
2400                         *negp = -1;
2401                         *lvalp = (unsigned long)-val;
2402                 } else {
2403                         *negp = 0;
2404                         *lvalp = (unsigned long)val;
2405                 }
2406         }
2407         return 0;
2408 }
2409
2410 /**
2411  * proc_dointvec_minmax - read a vector of integers with min/max values
2412  * @table: the sysctl table
2413  * @write: %TRUE if this is a write to the sysctl file
2414  * @filp: the file structure
2415  * @buffer: the user buffer
2416  * @lenp: the size of the user buffer
2417  * @ppos: file position
2418  *
2419  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2420  * values from/to the user buffer, treated as an ASCII string.
2421  *
2422  * This routine will ensure the values are within the range specified by
2423  * table->extra1 (min) and table->extra2 (max).
2424  *
2425  * Returns 0 on success.
2426  */
2427 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2428                   void __user *buffer, size_t *lenp, loff_t *ppos)
2429 {
2430         struct do_proc_dointvec_minmax_conv_param param = {
2431                 .min = (int *) table->extra1,
2432                 .max = (int *) table->extra2,
2433         };
2434         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2435                                 do_proc_dointvec_minmax_conv, &param);
2436 }
2437
2438 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2439                                      struct file *filp,
2440                                      void __user *buffer,
2441                                      size_t *lenp, loff_t *ppos,
2442                                      unsigned long convmul,
2443                                      unsigned long convdiv)
2444 {
2445 #define TMPBUFLEN 21
2446         unsigned long *i, *min, *max, val;
2447         int vleft, first=1, neg;
2448         size_t len, left;
2449         char buf[TMPBUFLEN], *p;
2450         char __user *s = buffer;
2451
2452         if (!data || !table->maxlen || !*lenp ||
2453             (*ppos && !write)) {
2454                 *lenp = 0;
2455                 return 0;
2456         }
2457
2458         i = (unsigned long *) data;
2459         min = (unsigned long *) table->extra1;
2460         max = (unsigned long *) table->extra2;
2461         vleft = table->maxlen / sizeof(unsigned long);
2462         left = *lenp;
2463
2464         for (; left && vleft--; i++, min++, max++, first=0) {
2465                 if (write) {
2466                         while (left) {
2467                                 char c;
2468                                 if (get_user(c, s))
2469                                         return -EFAULT;
2470                                 if (!isspace(c))
2471                                         break;
2472                                 left--;
2473                                 s++;
2474                         }
2475                         if (!left)
2476                                 break;
2477                         neg = 0;
2478                         len = left;
2479                         if (len > TMPBUFLEN-1)
2480                                 len = TMPBUFLEN-1;
2481                         if (copy_from_user(buf, s, len))
2482                                 return -EFAULT;
2483                         buf[len] = 0;
2484                         p = buf;
2485                         if (*p == '-' && left > 1) {
2486                                 neg = 1;
2487                                 p++;
2488                         }
2489                         if (*p < '0' || *p > '9')
2490                                 break;
2491                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2492                         len = p-buf;
2493                         if ((len < left) && *p && !isspace(*p))
2494                                 break;
2495                         if (neg)
2496                                 val = -val;
2497                         s += len;
2498                         left -= len;
2499
2500                         if(neg)
2501                                 continue;
2502                         if ((min && val < *min) || (max && val > *max))
2503                                 continue;
2504                         *i = val;
2505                 } else {
2506                         p = buf;
2507                         if (!first)
2508                                 *p++ = '\t';
2509                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2510                         len = strlen(buf);
2511                         if (len > left)
2512                                 len = left;
2513                         if(copy_to_user(s, buf, len))
2514                                 return -EFAULT;
2515                         left -= len;
2516                         s += len;
2517                 }
2518         }
2519
2520         if (!write && !first && left) {
2521                 if(put_user('\n', s))
2522                         return -EFAULT;
2523                 left--, s++;
2524         }
2525         if (write) {
2526                 while (left) {
2527                         char c;
2528                         if (get_user(c, s++))
2529                                 return -EFAULT;
2530                         if (!isspace(c))
2531                                 break;
2532                         left--;
2533                 }
2534         }
2535         if (write && first)
2536                 return -EINVAL;
2537         *lenp -= left;
2538         *ppos += *lenp;
2539         return 0;
2540 #undef TMPBUFLEN
2541 }
2542
2543 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2544                                      struct file *filp,
2545                                      void __user *buffer,
2546                                      size_t *lenp, loff_t *ppos,
2547                                      unsigned long convmul,
2548                                      unsigned long convdiv)
2549 {
2550         return __do_proc_doulongvec_minmax(table->data, table, write,
2551                         filp, buffer, lenp, ppos, convmul, convdiv);
2552 }
2553
2554 /**
2555  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2556  * @table: the sysctl table
2557  * @write: %TRUE if this is a write to the sysctl file
2558  * @filp: the file structure
2559  * @buffer: the user buffer
2560  * @lenp: the size of the user buffer
2561  * @ppos: file position
2562  *
2563  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2564  * values from/to the user buffer, treated as an ASCII string.
2565  *
2566  * This routine will ensure the values are within the range specified by
2567  * table->extra1 (min) and table->extra2 (max).
2568  *
2569  * Returns 0 on success.
2570  */
2571 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2572                            void __user *buffer, size_t *lenp, loff_t *ppos)
2573 {
2574     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2575 }
2576
2577 /**
2578  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2579  * @table: the sysctl table
2580  * @write: %TRUE if this is a write to the sysctl file
2581  * @filp: the file structure
2582  * @buffer: the user buffer
2583  * @lenp: the size of the user buffer
2584  * @ppos: file position
2585  *
2586  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2587  * values from/to the user buffer, treated as an ASCII string. The values
2588  * are treated as milliseconds, and converted to jiffies when they are stored.
2589  *
2590  * This routine will ensure the values are within the range specified by
2591  * table->extra1 (min) and table->extra2 (max).
2592  *
2593  * Returns 0 on success.
2594  */
2595 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2596                                       struct file *filp,
2597                                       void __user *buffer,
2598                                       size_t *lenp, loff_t *ppos)
2599 {
2600     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2601                                      lenp, ppos, HZ, 1000l);
2602 }
2603
2604
2605 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2606                                          int *valp,
2607                                          int write, void *data)
2608 {
2609         if (write) {
2610                 if (*lvalp > LONG_MAX / HZ)
2611                         return 1;
2612                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2613         } else {
2614                 int val = *valp;
2615                 unsigned long lval;
2616                 if (val < 0) {
2617                         *negp = -1;
2618                         lval = (unsigned long)-val;
2619                 } else {
2620                         *negp = 0;
2621                         lval = (unsigned long)val;
2622                 }
2623                 *lvalp = lval / HZ;
2624         }
2625         return 0;
2626 }
2627
2628 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2629                                                 int *valp,
2630                                                 int write, void *data)
2631 {
2632         if (write) {
2633                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2634                         return 1;
2635                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2636         } else {
2637                 int val = *valp;
2638                 unsigned long lval;
2639                 if (val < 0) {
2640                         *negp = -1;
2641                         lval = (unsigned long)-val;
2642                 } else {
2643                         *negp = 0;
2644                         lval = (unsigned long)val;
2645                 }
2646                 *lvalp = jiffies_to_clock_t(lval);
2647         }
2648         return 0;
2649 }
2650
2651 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2652                                             int *valp,
2653                                             int write, void *data)
2654 {
2655         if (write) {
2656                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2657         } else {
2658                 int val = *valp;
2659                 unsigned long lval;
2660                 if (val < 0) {
2661                         *negp = -1;
2662                         lval = (unsigned long)-val;
2663                 } else {
2664                         *negp = 0;
2665                         lval = (unsigned long)val;
2666                 }
2667                 *lvalp = jiffies_to_msecs(lval);
2668         }
2669         return 0;
2670 }
2671
2672 /**
2673  * proc_dointvec_jiffies - read a vector of integers as seconds
2674  * @table: the sysctl table
2675  * @write: %TRUE if this is a write to the sysctl file
2676  * @filp: the file structure
2677  * @buffer: the user buffer
2678  * @lenp: the size of the user buffer
2679  * @ppos: file position
2680  *
2681  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2682  * values from/to the user buffer, treated as an ASCII string.
2683  * The values read are assumed to be in seconds, and are converted into
2684  * jiffies.
2685  *
2686  * Returns 0 on success.
2687  */
2688 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2689                           void __user *buffer, size_t *lenp, loff_t *ppos)
2690 {
2691     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2692                             do_proc_dointvec_jiffies_conv,NULL);
2693 }
2694
2695 /**
2696  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2697  * @table: the sysctl table
2698  * @write: %TRUE if this is a write to the sysctl file
2699  * @filp: the file structure
2700  * @buffer: the user buffer
2701  * @lenp: the size of the user buffer
2702  * @ppos: pointer to the file position
2703  *
2704  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2705  * values from/to the user buffer, treated as an ASCII string.
2706  * The values read are assumed to be in 1/USER_HZ seconds, and
2707  * are converted into jiffies.
2708  *
2709  * Returns 0 on success.
2710  */
2711 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2712                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2713 {
2714     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2715                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2716 }
2717
2718 /**
2719  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2720  * @table: the sysctl table
2721  * @write: %TRUE if this is a write to the sysctl file
2722  * @filp: the file structure
2723  * @buffer: the user buffer
2724  * @lenp: the size of the user buffer
2725  * @ppos: file position
2726  * @ppos: the current position in the file
2727  *
2728  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2729  * values from/to the user buffer, treated as an ASCII string.
2730  * The values read are assumed to be in 1/1000 seconds, and
2731  * are converted into jiffies.
2732  *
2733  * Returns 0 on success.
2734  */
2735 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2736                              void __user *buffer, size_t *lenp, loff_t *ppos)
2737 {
2738         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2739                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2740 }
2741
2742 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2743                            void __user *buffer, size_t *lenp, loff_t *ppos)
2744 {
2745         struct pid *new_pid;
2746         pid_t tmp;
2747         int r;
2748
2749         tmp = pid_vnr(cad_pid);
2750
2751         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2752                                lenp, ppos, NULL, NULL);
2753         if (r || !write)
2754                 return r;
2755
2756         new_pid = find_get_pid(tmp);
2757         if (!new_pid)
2758                 return -ESRCH;
2759
2760         put_pid(xchg(&cad_pid, new_pid));
2761         return 0;
2762 }
2763
2764 #else /* CONFIG_PROC_FS */
2765
2766 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2767                   void __user *buffer, size_t *lenp, loff_t *ppos)
2768 {
2769         return -ENOSYS;
2770 }
2771
2772 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2773                   void __user *buffer, size_t *lenp, loff_t *ppos)
2774 {
2775         return -ENOSYS;
2776 }
2777
2778 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2779                     void __user *buffer, size_t *lenp, loff_t *ppos)
2780 {
2781         return -ENOSYS;
2782 }
2783
2784 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2785                     void __user *buffer, size_t *lenp, loff_t *ppos)
2786 {
2787         return -ENOSYS;
2788 }
2789
2790 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2791                     void __user *buffer, size_t *lenp, loff_t *ppos)
2792 {
2793         return -ENOSYS;
2794 }
2795
2796 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2797                              void __user *buffer, size_t *lenp, loff_t *ppos)
2798 {
2799         return -ENOSYS;
2800 }
2801
2802 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2803                     void __user *buffer, size_t *lenp, loff_t *ppos)
2804 {
2805         return -ENOSYS;
2806 }
2807
2808 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2809                                       struct file *filp,
2810                                       void __user *buffer,
2811                                       size_t *lenp, loff_t *ppos)
2812 {
2813     return -ENOSYS;
2814 }
2815
2816
2817 #endif /* CONFIG_PROC_FS */
2818
2819
2820 #ifdef CONFIG_SYSCTL_SYSCALL
2821 /*
2822  * General sysctl support routines
2823  */
2824
2825 /* The generic sysctl data routine (used if no strategy routine supplied) */
2826 int sysctl_data(struct ctl_table *table,
2827                 void __user *oldval, size_t __user *oldlenp,
2828                 void __user *newval, size_t newlen)
2829 {
2830         size_t len;
2831
2832         /* Get out of I don't have a variable */
2833         if (!table->data || !table->maxlen)
2834                 return -ENOTDIR;
2835
2836         if (oldval && oldlenp) {
2837                 if (get_user(len, oldlenp))
2838                         return -EFAULT;
2839                 if (len) {
2840                         if (len > table->maxlen)
2841                                 len = table->maxlen;
2842                         if (copy_to_user(oldval, table->data, len))
2843                                 return -EFAULT;
2844                         if (put_user(len, oldlenp))
2845                                 return -EFAULT;
2846                 }
2847         }
2848
2849         if (newval && newlen) {
2850                 if (newlen > table->maxlen)
2851                         newlen = table->maxlen;
2852
2853                 if (copy_from_user(table->data, newval, newlen))
2854                         return -EFAULT;
2855         }
2856         return 1;
2857 }
2858
2859 /* The generic string strategy routine: */
2860 int sysctl_string(struct ctl_table *table,
2861                   void __user *oldval, size_t __user *oldlenp,
2862                   void __user *newval, size_t newlen)
2863 {
2864         if (!table->data || !table->maxlen)
2865                 return -ENOTDIR;
2866
2867         if (oldval && oldlenp) {
2868                 size_t bufsize;
2869                 if (get_user(bufsize, oldlenp))
2870                         return -EFAULT;
2871                 if (bufsize) {
2872                         size_t len = strlen(table->data), copied;
2873
2874                         /* This shouldn't trigger for a well-formed sysctl */
2875                         if (len > table->maxlen)
2876                                 len = table->maxlen;
2877
2878                         /* Copy up to a max of bufsize-1 bytes of the string */
2879                         copied = (len >= bufsize) ? bufsize - 1 : len;
2880
2881                         if (copy_to_user(oldval, table->data, copied) ||
2882                             put_user(0, (char __user *)(oldval + copied)))
2883                                 return -EFAULT;
2884                         if (put_user(len, oldlenp))
2885                                 return -EFAULT;
2886                 }
2887         }
2888         if (newval && newlen) {
2889                 size_t len = newlen;
2890                 if (len > table->maxlen)
2891                         len = table->maxlen;
2892                 if(copy_from_user(table->data, newval, len))
2893                         return -EFAULT;
2894                 if (len == table->maxlen)
2895                         len--;
2896                 ((char *) table->data)[len] = 0;
2897         }
2898         return 1;
2899 }
2900
2901 /*
2902  * This function makes sure that all of the integers in the vector
2903  * are between the minimum and maximum values given in the arrays
2904  * table->extra1 and table->extra2, respectively.
2905  */
2906 int sysctl_intvec(struct ctl_table *table,
2907                 void __user *oldval, size_t __user *oldlenp,
2908                 void __user *newval, size_t newlen)
2909 {
2910
2911         if (newval && newlen) {
2912                 int __user *vec = (int __user *) newval;
2913                 int *min = (int *) table->extra1;
2914                 int *max = (int *) table->extra2;
2915                 size_t length;
2916                 int i;
2917
2918                 if (newlen % sizeof(int) != 0)
2919                         return -EINVAL;
2920
2921                 if (!table->extra1 && !table->extra2)
2922                         return 0;
2923
2924                 if (newlen > table->maxlen)
2925                         newlen = table->maxlen;
2926                 length = newlen / sizeof(int);
2927
2928                 for (i = 0; i < length; i++) {
2929                         int value;
2930                         if (get_user(value, vec + i))
2931                                 return -EFAULT;
2932                         if (min && value < min[i])
2933                                 return -EINVAL;
2934                         if (max && value > max[i])
2935                                 return -EINVAL;
2936                 }
2937         }
2938         return 0;
2939 }
2940
2941 /* Strategy function to convert jiffies to seconds */
2942 int sysctl_jiffies(struct ctl_table *table,
2943                 void __user *oldval, size_t __user *oldlenp,
2944                 void __user *newval, size_t newlen)
2945 {
2946         if (oldval && oldlenp) {
2947                 size_t olen;
2948
2949                 if (get_user(olen, oldlenp))
2950                         return -EFAULT;
2951                 if (olen) {
2952                         int val;
2953
2954                         if (olen < sizeof(int))
2955                                 return -EINVAL;
2956
2957                         val = *(int *)(table->data) / HZ;
2958                         if (put_user(val, (int __user *)oldval))
2959                                 return -EFAULT;
2960                         if (put_user(sizeof(int), oldlenp))
2961                                 return -EFAULT;
2962                 }
2963         }
2964         if (newval && newlen) {
2965                 int new;
2966                 if (newlen != sizeof(int))
2967                         return -EINVAL;
2968                 if (get_user(new, (int __user *)newval))
2969                         return -EFAULT;
2970                 *(int *)(table->data) = new*HZ;
2971         }
2972         return 1;
2973 }
2974
2975 /* Strategy function to convert jiffies to seconds */
2976 int sysctl_ms_jiffies(struct ctl_table *table,
2977                 void __user *oldval, size_t __user *oldlenp,
2978                 void __user *newval, size_t newlen)
2979 {
2980         if (oldval && oldlenp) {
2981                 size_t olen;
2982
2983                 if (get_user(olen, oldlenp))
2984                         return -EFAULT;
2985                 if (olen) {
2986                         int val;
2987
2988                         if (olen < sizeof(int))
2989                                 return -EINVAL;
2990
2991                         val = jiffies_to_msecs(*(int *)(table->data));
2992                         if (put_user(val, (int __user *)oldval))
2993                                 return -EFAULT;
2994                         if (put_user(sizeof(int), oldlenp))
2995                                 return -EFAULT;
2996                 }
2997         }
2998         if (newval && newlen) {
2999                 int new;
3000                 if (newlen != sizeof(int))
3001                         return -EINVAL;
3002                 if (get_user(new, (int __user *)newval))
3003                         return -EFAULT;
3004                 *(int *)(table->data) = msecs_to_jiffies(new);
3005         }
3006         return 1;
3007 }
3008
3009
3010
3011 #else /* CONFIG_SYSCTL_SYSCALL */
3012
3013
3014 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3015 {
3016         struct __sysctl_args tmp;
3017         int error;
3018
3019         if (copy_from_user(&tmp, args, sizeof(tmp)))
3020                 return -EFAULT;
3021
3022         error = deprecated_sysctl_warning(&tmp);
3023
3024         /* If no error reading the parameters then just -ENOSYS ... */
3025         if (!error)
3026                 error = -ENOSYS;
3027
3028         return error;
3029 }
3030
3031 int sysctl_data(struct ctl_table *table,
3032                   void __user *oldval, size_t __user *oldlenp,
3033                   void __user *newval, size_t newlen)
3034 {
3035         return -ENOSYS;
3036 }
3037
3038 int sysctl_string(struct ctl_table *table,
3039                   void __user *oldval, size_t __user *oldlenp,
3040                   void __user *newval, size_t newlen)
3041 {
3042         return -ENOSYS;
3043 }
3044
3045 int sysctl_intvec(struct ctl_table *table,
3046                 void __user *oldval, size_t __user *oldlenp,
3047                 void __user *newval, size_t newlen)
3048 {
3049         return -ENOSYS;
3050 }
3051
3052 int sysctl_jiffies(struct ctl_table *table,
3053                 void __user *oldval, size_t __user *oldlenp,
3054                 void __user *newval, size_t newlen)
3055 {
3056         return -ENOSYS;
3057 }
3058
3059 int sysctl_ms_jiffies(struct ctl_table *table,
3060                 void __user *oldval, size_t __user *oldlenp,
3061                 void __user *newval, size_t newlen)
3062 {
3063         return -ENOSYS;
3064 }
3065
3066 #endif /* CONFIG_SYSCTL_SYSCALL */
3067
3068 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3069 {
3070         static int msg_count;
3071         int name[CTL_MAXNAME];
3072         int i;
3073
3074         /* Check args->nlen. */
3075         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3076                 return -ENOTDIR;
3077
3078         /* Read in the sysctl name for better debug message logging */
3079         for (i = 0; i < args->nlen; i++)
3080                 if (get_user(name[i], args->name + i))
3081                         return -EFAULT;
3082
3083         /* Ignore accesses to kernel.version */
3084         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3085                 return 0;
3086
3087         if (msg_count < 5) {
3088                 msg_count++;
3089                 printk(KERN_INFO
3090                         "warning: process `%s' used the deprecated sysctl "
3091                         "system call with ", current->comm);
3092                 for (i = 0; i < args->nlen; i++)
3093                         printk("%d.", name[i]);
3094                 printk("\n");
3095         }
3096         return 0;
3097 }
3098
3099 /*
3100  * No sense putting this after each symbol definition, twice,
3101  * exception granted :-)
3102  */
3103 EXPORT_SYMBOL(proc_dointvec);
3104 EXPORT_SYMBOL(proc_dointvec_jiffies);
3105 EXPORT_SYMBOL(proc_dointvec_minmax);
3106 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3107 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3108 EXPORT_SYMBOL(proc_dostring);
3109 EXPORT_SYMBOL(proc_doulongvec_minmax);
3110 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3111 EXPORT_SYMBOL(register_sysctl_table);
3112 EXPORT_SYMBOL(register_sysctl_paths);
3113 EXPORT_SYMBOL(sysctl_intvec);
3114 EXPORT_SYMBOL(sysctl_jiffies);
3115 EXPORT_SYMBOL(sysctl_ms_jiffies);
3116 EXPORT_SYMBOL(sysctl_string);
3117 EXPORT_SYMBOL(sysctl_data);
3118 EXPORT_SYMBOL(unregister_sysctl_table);