kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/aio.h>
  23 #include <linux/mm.h>
  24 #include <linux/swap.h>
  25 #include <linux/slab.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/bitmap.h>
  28 #include <linux/signal.h>
  29 #include <linux/printk.h>
  30 #include <linux/proc_fs.h>
  31 #include <linux/security.h>
  32 #include <linux/ctype.h>
  33 #include <linux/kmemcheck.h>
  34 #include <linux/kmemleak.h>
  35 #include <linux/fs.h>
  36 #include <linux/init.h>
  37 #include <linux/kernel.h>
  38 #include <linux/kobject.h>
  39 #include <linux/net.h>
  40 #include <linux/sysrq.h>
  41 #include <linux/highuid.h>
  42 #include <linux/writeback.h>
  43 #include <linux/ratelimit.h>
  44 #include <linux/compaction.h>
  45 #include <linux/hugetlb.h>
  46 #include <linux/initrd.h>
  47 #include <linux/key.h>
  48 #include <linux/times.h>
  49 #include <linux/limits.h>
  50 #include <linux/dcache.h>
  51 #include <linux/dnotify.h>
  52 #include <linux/syscalls.h>
  53 #include <linux/vmstat.h>
  54 #include <linux/nfs_fs.h>
  55 #include <linux/acpi.h>
  56 #include <linux/reboot.h>
  57 #include <linux/ftrace.h>
  58 #include <linux/perf_event.h>
  59 #include <linux/kprobes.h>
  60 #include <linux/pipe_fs_i.h>
  61 #include <linux/oom.h>
  62 #include <linux/kmod.h>
  63 #include <linux/capability.h>
  64 #include <linux/binfmts.h>
  65 #include <linux/sched/sysctl.h>
  66 #include <linux/kexec.h>
  67 #include <linux/bpf.h>
  68
  69 #include <asm/uaccess.h>
  70 #include <asm/processor.h>
  71
  72 #ifdef CONFIG_X86
  73 #include <asm/nmi.h>
  74 #include <asm/stacktrace.h>
  75 #include <asm/io.h>
  76 #endif
  77 #ifdef CONFIG_SPARC
  78 #include <asm/setup.h>
  79 #endif
  80 #ifdef CONFIG_BSD_PROCESS_ACCT
  81 #include <linux/acct.h>
  82 #endif
  83 #ifdef CONFIG_RT_MUTEXES
  84 #include <linux/rtmutex.h>
  85 #endif
  86 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  87 #include <linux/lockdep.h>
  88 #endif
  89 #ifdef CONFIG_CHR_DEV_SG
  90 #include <scsi/sg.h>
  91 #endif
  92
  93 #ifdef CONFIG_LOCKUP_DETECTOR
  94 #include <linux/nmi.h>
  95 #endif
  96
  97 #if defined(CONFIG_SYSCTL)
  98
  99 /* External variables not in a header file. */
 100 extern int suid_dumpable;
 101 #ifdef CONFIG_COREDUMP
 102 extern int core_uses_pid;
 103 extern char core_pattern[];
 104 extern unsigned int core_pipe_limit;
 105 #endif
 106 extern int pid_max;
 107 extern int pid_max_min, pid_max_max;
 108 extern int percpu_pagelist_fraction;
 109 extern int compat_log;
 110 extern int latencytop_enabled;
 111 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 112 #ifndef CONFIG_MMU
 113 extern int sysctl_nr_trim_pages;
 114 #endif
 115
 116 /* Constants used for minimum and  maximum */
 117 #ifdef CONFIG_LOCKUP_DETECTOR
 118 static int sixty = 60;
 119 #endif
 120
 121 static int __maybe_unused neg_one = -1;
 122
 123 static int zero;
 124 static int __maybe_unused one = 1;
 125 static int __maybe_unused two = 2;
 126 static int __maybe_unused four = 4;
 127 static unsigned long one_ul = 1;
 128 static int one_hundred = 100;
 129 #ifdef CONFIG_PRINTK
 130 static int ten_thousand = 10000;
 131 #endif
 132
 133 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 134 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 135
 136 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 137 static int maxolduid = 65535;
 138 static int minolduid;
 139
 140 static int ngroups_max = NGROUPS_MAX;
 141 static const int cap_last_cap = CAP_LAST_CAP;
 142
 143 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
 144 #ifdef CONFIG_DETECT_HUNG_TASK
 145 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
 146 #endif
 147
 148 #ifdef CONFIG_INOTIFY_USER
 149 #include <linux/inotify.h>
 150 #endif
 151 #ifdef CONFIG_SPARC
 152 #endif
 153
 154 #ifdef __hppa__
 155 extern int pwrsw_enabled;
 156 #endif
 157
 158 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 159 extern int unaligned_enabled;
 160 #endif
 161
 162 #ifdef CONFIG_IA64
 163 extern int unaligned_dump_stack;
 164 #endif
 165
 166 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 167 extern int no_unaligned_warning;
 168 #endif
 169
 170 #ifdef CONFIG_PROC_SYSCTL
 171
 172 #define SYSCTL_WRITES_LEGACY    -1
 173 #define SYSCTL_WRITES_WARN       0
 174 #define SYSCTL_WRITES_STRICT     1
 175
 176 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
 177
 178 static int proc_do_cad_pid(struct ctl_table *table, int write,
 179                   void __user *buffer, size_t *lenp, loff_t *ppos);
 180 static int proc_taint(struct ctl_table *table, int write,
 181                                void __user *buffer, size_t *lenp, loff_t *ppos);
 182 #endif
 183
 184 #ifdef CONFIG_PRINTK
 185 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
 186                                 void __user *buffer, size_t *lenp, loff_t *ppos);
 187 #endif
 188
 189 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
 190                 void __user *buffer, size_t *lenp, loff_t *ppos);
 191 #ifdef CONFIG_COREDUMP
 192 static int proc_dostring_coredump(struct ctl_table *table, int write,
 193                 void __user *buffer, size_t *lenp, loff_t *ppos);
 194 #endif
 195
 196 #ifdef CONFIG_MAGIC_SYSRQ
 197 /* Note: sysrq code uses it's own private copy */
 198 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
 199
 200 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
 201                                 void __user *buffer, size_t *lenp,
 202                                 loff_t *ppos)
 203 {
 204         int error;
 205
 206         error = proc_dointvec(table, write, buffer, lenp, ppos);
 207         if (error)
 208                 return error;
 209
 210         if (write)
 211                 sysrq_toggle_support(__sysrq_enabled);
 212
 213         return 0;
 214 }
 215
 216 #endif
 217
 218 static struct ctl_table kern_table[];
 219 static struct ctl_table vm_table[];
 220 static struct ctl_table fs_table[];
 221 static struct ctl_table debug_table[];
 222 static struct ctl_table dev_table[];
 223 extern struct ctl_table random_table[];
 224 #ifdef CONFIG_EPOLL
 225 extern struct ctl_table epoll_table[];
 226 #endif
 227
 228 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 229 int sysctl_legacy_va_layout;
 230 #endif
 231
 232 /* The default sysctl tables: */
 233
 234 static struct ctl_table sysctl_base_table[] = {
 235         {
 236                 .procname       = "kernel",
 237                 .mode           = 0555,
 238                 .child          = kern_table,
 239         },
 240         {
 241                 .procname       = "vm",
 242                 .mode           = 0555,
 243                 .child          = vm_table,
 244         },
 245         {
 246                 .procname       = "fs",
 247                 .mode           = 0555,
 248                 .child          = fs_table,
 249         },
 250         {
 251                 .procname       = "debug",
 252                 .mode           = 0555,
 253                 .child          = debug_table,
 254         },
 255         {
 256                 .procname       = "dev",
 257                 .mode           = 0555,
 258                 .child          = dev_table,
 259         },
 260         { }
 261 };
 262
 263 #ifdef CONFIG_SCHED_DEBUG
 264 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 265 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 266 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 267 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 268 #ifdef CONFIG_SMP
 269 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 270 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 271 #endif /* CONFIG_SMP */
 272 #endif /* CONFIG_SCHED_DEBUG */
 273
 274 #ifdef CONFIG_COMPACTION
 275 static int min_extfrag_threshold;
 276 static int max_extfrag_threshold = 1000;
 277 #endif
 278
 279 static struct ctl_table kern_table[] = {
 280         {
 281                 .procname       = "sched_child_runs_first",
 282                 .data           = &sysctl_sched_child_runs_first,
 283                 .maxlen         = sizeof(unsigned int),
 284                 .mode           = 0644,
 285                 .proc_handler   = proc_dointvec,
 286         },
 287 #ifdef CONFIG_SCHED_DEBUG
 288         {
 289                 .procname       = "sched_min_granularity_ns",
 290                 .data           = &sysctl_sched_min_granularity,
 291                 .maxlen         = sizeof(unsigned int),
 292                 .mode           = 0644,
 293                 .proc_handler   = sched_proc_update_handler,
 294                 .extra1         = &min_sched_granularity_ns,
 295                 .extra2         = &max_sched_granularity_ns,
 296         },
 297         {
 298                 .procname       = "sched_latency_ns",
 299                 .data           = &sysctl_sched_latency,
 300                 .maxlen         = sizeof(unsigned int),
 301                 .mode           = 0644,
 302                 .proc_handler   = sched_proc_update_handler,
 303                 .extra1         = &min_sched_granularity_ns,
 304                 .extra2         = &max_sched_granularity_ns,
 305         },
 306         {
 307                 .procname       = "sched_wakeup_granularity_ns",
 308                 .data           = &sysctl_sched_wakeup_granularity,
 309                 .maxlen         = sizeof(unsigned int),
 310                 .mode           = 0644,
 311                 .proc_handler   = sched_proc_update_handler,
 312                 .extra1         = &min_wakeup_granularity_ns,
 313                 .extra2         = &max_wakeup_granularity_ns,
 314         },
 315 #ifdef CONFIG_SMP
 316         {
 317                 .procname       = "sched_tunable_scaling",
 318                 .data           = &sysctl_sched_tunable_scaling,
 319                 .maxlen         = sizeof(enum sched_tunable_scaling),
 320                 .mode           = 0644,
 321                 .proc_handler   = sched_proc_update_handler,
 322                 .extra1         = &min_sched_tunable_scaling,
 323                 .extra2         = &max_sched_tunable_scaling,
 324         },
 325         {
 326                 .procname       = "sched_migration_cost_ns",
 327                 .data           = &sysctl_sched_migration_cost,
 328                 .maxlen         = sizeof(unsigned int),
 329                 .mode           = 0644,
 330                 .proc_handler   = proc_dointvec,
 331         },
 332         {
 333                 .procname       = "sched_nr_migrate",
 334                 .data           = &sysctl_sched_nr_migrate,
 335                 .maxlen         = sizeof(unsigned int),
 336                 .mode           = 0644,
 337                 .proc_handler   = proc_dointvec,
 338         },
 339         {
 340                 .procname       = "sched_time_avg_ms",
 341                 .data           = &sysctl_sched_time_avg,
 342                 .maxlen         = sizeof(unsigned int),
 343                 .mode           = 0644,
 344                 .proc_handler   = proc_dointvec,
 345         },
 346         {
 347                 .procname       = "sched_shares_window_ns",
 348                 .data           = &sysctl_sched_shares_window,
 349                 .maxlen         = sizeof(unsigned int),
 350                 .mode           = 0644,
 351                 .proc_handler   = proc_dointvec,
 352         },
 353 #endif /* CONFIG_SMP */
 354 #ifdef CONFIG_NUMA_BALANCING
 355         {
 356                 .procname       = "numa_balancing_scan_delay_ms",
 357                 .data           = &sysctl_numa_balancing_scan_delay,
 358                 .maxlen         = sizeof(unsigned int),
 359                 .mode           = 0644,
 360                 .proc_handler   = proc_dointvec,
 361         },
 362         {
 363                 .procname       = "numa_balancing_scan_period_min_ms",
 364                 .data           = &sysctl_numa_balancing_scan_period_min,
 365                 .maxlen         = sizeof(unsigned int),
 366                 .mode           = 0644,
 367                 .proc_handler   = proc_dointvec,
 368         },
 369         {
 370                 .procname       = "numa_balancing_scan_period_max_ms",
 371                 .data           = &sysctl_numa_balancing_scan_period_max,
 372                 .maxlen         = sizeof(unsigned int),
 373                 .mode           = 0644,
 374                 .proc_handler   = proc_dointvec,
 375         },
 376         {
 377                 .procname       = "numa_balancing_scan_size_mb",
 378                 .data           = &sysctl_numa_balancing_scan_size,
 379                 .maxlen         = sizeof(unsigned int),
 380                 .mode           = 0644,
 381                 .proc_handler   = proc_dointvec_minmax,
 382                 .extra1         = &one,
 383         },
 384         {
 385                 .procname       = "numa_balancing",
 386                 .data           = NULL, /* filled in by handler */
 387                 .maxlen         = sizeof(unsigned int),
 388                 .mode           = 0644,
 389                 .proc_handler   = sysctl_numa_balancing,
 390                 .extra1         = &zero,
 391                 .extra2         = &one,
 392         },
 393 #endif /* CONFIG_NUMA_BALANCING */
 394 #endif /* CONFIG_SCHED_DEBUG */
 395         {
 396                 .procname       = "sched_rt_period_us",
 397                 .data           = &sysctl_sched_rt_period,
 398                 .maxlen         = sizeof(unsigned int),
 399                 .mode           = 0644,
 400                 .proc_handler   = sched_rt_handler,
 401         },
 402         {
 403                 .procname       = "sched_rt_runtime_us",
 404                 .data           = &sysctl_sched_rt_runtime,
 405                 .maxlen         = sizeof(int),
 406                 .mode           = 0644,
 407                 .proc_handler   = sched_rt_handler,
 408         },
 409         {
 410                 .procname       = "sched_rr_timeslice_ms",
 411                 .data           = &sched_rr_timeslice,
 412                 .maxlen         = sizeof(int),
 413                 .mode           = 0644,
 414                 .proc_handler   = sched_rr_handler,
 415         },
 416 #ifdef CONFIG_SCHED_AUTOGROUP
 417         {
 418                 .procname       = "sched_autogroup_enabled",
 419                 .data           = &sysctl_sched_autogroup_enabled,
 420                 .maxlen         = sizeof(unsigned int),
 421                 .mode           = 0644,
 422                 .proc_handler   = proc_dointvec_minmax,
 423                 .extra1         = &zero,
 424                 .extra2         = &one,
 425         },
 426 #endif
 427 #ifdef CONFIG_CFS_BANDWIDTH
 428         {
 429                 .procname       = "sched_cfs_bandwidth_slice_us",
 430                 .data           = &sysctl_sched_cfs_bandwidth_slice,
 431                 .maxlen         = sizeof(unsigned int),
 432                 .mode           = 0644,
 433                 .proc_handler   = proc_dointvec_minmax,
 434                 .extra1         = &one,
 435         },
 436 #endif
 437 #ifdef CONFIG_PROVE_LOCKING
 438         {
 439                 .procname       = "prove_locking",
 440                 .data           = &prove_locking,
 441                 .maxlen         = sizeof(int),
 442                 .mode           = 0644,
 443                 .proc_handler   = proc_dointvec,
 444         },
 445 #endif
 446 #ifdef CONFIG_LOCK_STAT
 447         {
 448                 .procname       = "lock_stat",
 449                 .data           = &lock_stat,
 450                 .maxlen         = sizeof(int),
 451                 .mode           = 0644,
 452                 .proc_handler   = proc_dointvec,
 453         },
 454 #endif
 455         {
 456                 .procname       = "panic",
 457                 .data           = &panic_timeout,
 458                 .maxlen         = sizeof(int),
 459                 .mode           = 0644,
 460                 .proc_handler   = proc_dointvec,
 461         },
 462 #ifdef CONFIG_COREDUMP
 463         {
 464                 .procname       = "core_uses_pid",
 465                 .data           = &core_uses_pid,
 466                 .maxlen         = sizeof(int),
 467                 .mode           = 0644,
 468                 .proc_handler   = proc_dointvec,
 469         },
 470         {
 471                 .procname       = "core_pattern",
 472                 .data           = core_pattern,
 473                 .maxlen         = CORENAME_MAX_SIZE,
 474                 .mode           = 0644,
 475                 .proc_handler   = proc_dostring_coredump,
 476         },
 477         {
 478                 .procname       = "core_pipe_limit",
 479                 .data           = &core_pipe_limit,
 480                 .maxlen         = sizeof(unsigned int),
 481                 .mode           = 0644,
 482                 .proc_handler   = proc_dointvec,
 483         },
 484 #endif
 485 #ifdef CONFIG_PROC_SYSCTL
 486         {
 487                 .procname       = "tainted",
 488                 .maxlen         = sizeof(long),
 489                 .mode           = 0644,
 490                 .proc_handler   = proc_taint,
 491         },
 492         {
 493                 .procname       = "sysctl_writes_strict",
 494                 .data           = &sysctl_writes_strict,
 495                 .maxlen         = sizeof(int),
 496                 .mode           = 0644,
 497                 .proc_handler   = proc_dointvec_minmax,
 498                 .extra1         = &neg_one,
 499                 .extra2         = &one,
 500         },
 501 #endif
 502 #ifdef CONFIG_LATENCYTOP
 503         {
 504                 .procname       = "latencytop",
 505                 .data           = &latencytop_enabled,
 506                 .maxlen         = sizeof(int),
 507                 .mode           = 0644,
 508                 .proc_handler   = proc_dointvec,
 509         },
 510 #endif
 511 #ifdef CONFIG_BLK_DEV_INITRD
 512         {
 513                 .procname       = "real-root-dev",
 514                 .data           = &real_root_dev,
 515                 .maxlen         = sizeof(int),
 516                 .mode           = 0644,
 517                 .proc_handler   = proc_dointvec,
 518         },
 519 #endif
 520         {
 521                 .procname       = "print-fatal-signals",
 522                 .data           = &print_fatal_signals,
 523                 .maxlen         = sizeof(int),
 524                 .mode           = 0644,
 525                 .proc_handler   = proc_dointvec,
 526         },
 527 #ifdef CONFIG_SPARC
 528         {
 529                 .procname       = "reboot-cmd",
 530                 .data           = reboot_command,
 531                 .maxlen         = 256,
 532                 .mode           = 0644,
 533                 .proc_handler   = proc_dostring,
 534         },
 535         {
 536                 .procname       = "stop-a",
 537                 .data           = &stop_a_enabled,
 538                 .maxlen         = sizeof (int),
 539                 .mode           = 0644,
 540                 .proc_handler   = proc_dointvec,
 541         },
 542         {
 543                 .procname       = "scons-poweroff",
 544                 .data           = &scons_pwroff,
 545                 .maxlen         = sizeof (int),
 546                 .mode           = 0644,
 547                 .proc_handler   = proc_dointvec,
 548         },
 549 #endif
 550 #ifdef CONFIG_SPARC64
 551         {
 552                 .procname       = "tsb-ratio",
 553                 .data           = &sysctl_tsb_ratio,
 554                 .maxlen         = sizeof (int),
 555                 .mode           = 0644,
 556                 .proc_handler   = proc_dointvec,
 557         },
 558 #endif
 559 #ifdef __hppa__
 560         {
 561                 .procname       = "soft-power",
 562                 .data           = &pwrsw_enabled,
 563                 .maxlen         = sizeof (int),
 564                 .mode           = 0644,
 565                 .proc_handler   = proc_dointvec,
 566         },
 567 #endif
 568 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 569         {
 570                 .procname       = "unaligned-trap",
 571                 .data           = &unaligned_enabled,
 572                 .maxlen         = sizeof (int),
 573                 .mode           = 0644,
 574                 .proc_handler   = proc_dointvec,
 575         },
 576 #endif
 577         {
 578                 .procname       = "ctrl-alt-del",
 579                 .data           = &C_A_D,
 580                 .maxlen         = sizeof(int),
 581                 .mode           = 0644,
 582                 .proc_handler   = proc_dointvec,
 583         },
 584 #ifdef CONFIG_FUNCTION_TRACER
 585         {
 586                 .procname       = "ftrace_enabled",
 587                 .data           = &ftrace_enabled,
 588                 .maxlen         = sizeof(int),
 589                 .mode           = 0644,
 590                 .proc_handler   = ftrace_enable_sysctl,
 591         },
 592 #endif
 593 #ifdef CONFIG_STACK_TRACER
 594         {
 595                 .procname       = "stack_tracer_enabled",
 596                 .data           = &stack_tracer_enabled,
 597                 .maxlen         = sizeof(int),
 598                 .mode           = 0644,
 599                 .proc_handler   = stack_trace_sysctl,
 600         },
 601 #endif
 602 #ifdef CONFIG_TRACING
 603         {
 604                 .procname       = "ftrace_dump_on_oops",
 605                 .data           = &ftrace_dump_on_oops,
 606                 .maxlen         = sizeof(int),
 607                 .mode           = 0644,
 608                 .proc_handler   = proc_dointvec,
 609         },
 610         {
 611                 .procname       = "traceoff_on_warning",
 612                 .data           = &__disable_trace_on_warning,
 613                 .maxlen         = sizeof(__disable_trace_on_warning),
 614                 .mode           = 0644,
 615                 .proc_handler   = proc_dointvec,
 616         },
 617         {
 618                 .procname       = "tracepoint_printk",
 619                 .data           = &tracepoint_printk,
 620                 .maxlen         = sizeof(tracepoint_printk),
 621                 .mode           = 0644,
 622                 .proc_handler   = proc_dointvec,
 623         },
 624 #endif
 625 #ifdef CONFIG_KEXEC_CORE
 626         {
 627                 .procname       = "kexec_load_disabled",
 628                 .data           = &kexec_load_disabled,
 629                 .maxlen         = sizeof(int),
 630                 .mode           = 0644,
 631                 /* only handle a transition from default "0" to "1" */
 632                 .proc_handler   = proc_dointvec_minmax,
 633                 .extra1         = &one,
 634                 .extra2         = &one,
 635         },
 636 #endif
 637 #ifdef CONFIG_MODULES
 638         {
 639                 .procname       = "modprobe",
 640                 .data           = &modprobe_path,
 641                 .maxlen         = KMOD_PATH_LEN,
 642                 .mode           = 0644,
 643                 .proc_handler   = proc_dostring,
 644         },
 645         {
 646                 .procname       = "modules_disabled",
 647                 .data           = &modules_disabled,
 648                 .maxlen         = sizeof(int),
 649                 .mode           = 0644,
 650                 /* only handle a transition from default "0" to "1" */
 651                 .proc_handler   = proc_dointvec_minmax,
 652                 .extra1         = &one,
 653                 .extra2         = &one,
 654         },
 655 #endif
 656 #ifdef CONFIG_UEVENT_HELPER
 657         {
 658                 .procname       = "hotplug",
 659                 .data           = &uevent_helper,
 660                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 661                 .mode           = 0644,
 662                 .proc_handler   = proc_dostring,
 663         },
 664 #endif
 665 #ifdef CONFIG_CHR_DEV_SG
 666         {
 667                 .procname       = "sg-big-buff",
 668                 .data           = &sg_big_buff,
 669                 .maxlen         = sizeof (int),
 670                 .mode           = 0444,
 671                 .proc_handler   = proc_dointvec,
 672         },
 673 #endif
 674 #ifdef CONFIG_BSD_PROCESS_ACCT
 675         {
 676                 .procname       = "acct",
 677                 .data           = &acct_parm,
 678                 .maxlen         = 3*sizeof(int),
 679                 .mode           = 0644,
 680                 .proc_handler   = proc_dointvec,
 681         },
 682 #endif
 683 #ifdef CONFIG_MAGIC_SYSRQ
 684         {
 685                 .procname       = "sysrq",
 686                 .data           = &__sysrq_enabled,
 687                 .maxlen         = sizeof (int),
 688                 .mode           = 0644,
 689                 .proc_handler   = sysrq_sysctl_handler,
 690         },
 691 #endif
 692 #ifdef CONFIG_PROC_SYSCTL
 693         {
 694                 .procname       = "cad_pid",
 695                 .data           = NULL,
 696                 .maxlen         = sizeof (int),
 697                 .mode           = 0600,
 698                 .proc_handler   = proc_do_cad_pid,
 699         },
 700 #endif
 701         {
 702                 .procname       = "threads-max",
 703                 .data           = NULL,
 704                 .maxlen         = sizeof(int),
 705                 .mode           = 0644,
 706                 .proc_handler   = sysctl_max_threads,
 707         },
 708         {
 709                 .procname       = "random",
 710                 .mode           = 0555,
 711                 .child          = random_table,
 712         },
 713         {
 714                 .procname       = "usermodehelper",
 715                 .mode           = 0555,
 716                 .child          = usermodehelper_table,
 717         },
 718         {
 719                 .procname       = "overflowuid",
 720                 .data           = &overflowuid,
 721                 .maxlen         = sizeof(int),
 722                 .mode           = 0644,
 723                 .proc_handler   = proc_dointvec_minmax,
 724                 .extra1         = &minolduid,
 725                 .extra2         = &maxolduid,
 726         },
 727         {
 728                 .procname       = "overflowgid",
 729                 .data           = &overflowgid,
 730                 .maxlen         = sizeof(int),
 731                 .mode           = 0644,
 732                 .proc_handler   = proc_dointvec_minmax,
 733                 .extra1         = &minolduid,
 734                 .extra2         = &maxolduid,
 735         },
 736 #ifdef CONFIG_S390
 737 #ifdef CONFIG_MATHEMU
 738         {
 739                 .procname       = "ieee_emulation_warnings",
 740                 .data           = &sysctl_ieee_emulation_warnings,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0644,
 743                 .proc_handler   = proc_dointvec,
 744         },
 745 #endif
 746         {
 747                 .procname       = "userprocess_debug",
 748                 .data           = &show_unhandled_signals,
 749                 .maxlen         = sizeof(int),
 750                 .mode           = 0644,
 751                 .proc_handler   = proc_dointvec,
 752         },
 753 #endif
 754         {
 755                 .procname       = "pid_max",
 756                 .data           = &pid_max,
 757                 .maxlen         = sizeof (int),
 758                 .mode           = 0644,
 759                 .proc_handler   = proc_dointvec_minmax,
 760                 .extra1         = &pid_max_min,
 761                 .extra2         = &pid_max_max,
 762         },
 763         {
 764                 .procname       = "panic_on_oops",
 765                 .data           = &panic_on_oops,
 766                 .maxlen         = sizeof(int),
 767                 .mode           = 0644,
 768                 .proc_handler   = proc_dointvec,
 769         },
 770 #if defined CONFIG_PRINTK
 771         {
 772                 .procname       = "printk",
 773                 .data           = &console_loglevel,
 774                 .maxlen         = 4*sizeof(int),
 775                 .mode           = 0644,
 776                 .proc_handler   = proc_dointvec,
 777         },
 778         {
 779                 .procname       = "printk_ratelimit",
 780                 .data           = &printk_ratelimit_state.interval,
 781                 .maxlen         = sizeof(int),
 782                 .mode           = 0644,
 783                 .proc_handler   = proc_dointvec_jiffies,
 784         },
 785         {
 786                 .procname       = "printk_ratelimit_burst",
 787                 .data           = &printk_ratelimit_state.burst,
 788                 .maxlen         = sizeof(int),
 789                 .mode           = 0644,
 790                 .proc_handler   = proc_dointvec,
 791         },
 792         {
 793                 .procname       = "printk_delay",
 794                 .data           = &printk_delay_msec,
 795                 .maxlen         = sizeof(int),
 796                 .mode           = 0644,
 797                 .proc_handler   = proc_dointvec_minmax,
 798                 .extra1         = &zero,
 799                 .extra2         = &ten_thousand,
 800         },
 801         {
 802                 .procname       = "dmesg_restrict",
 803                 .data           = &dmesg_restrict,
 804                 .maxlen         = sizeof(int),
 805                 .mode           = 0644,
 806                 .proc_handler   = proc_dointvec_minmax_sysadmin,
 807                 .extra1         = &zero,
 808                 .extra2         = &one,
 809         },
 810         {
 811                 .procname       = "kptr_restrict",
 812                 .data           = &kptr_restrict,
 813                 .maxlen         = sizeof(int),
 814                 .mode           = 0644,
 815                 .proc_handler   = proc_dointvec_minmax_sysadmin,
 816                 .extra1         = &zero,
 817                 .extra2         = &two,
 818         },
 819 #endif
 820         {
 821                 .procname       = "ngroups_max",
 822                 .data           = &ngroups_max,
 823                 .maxlen         = sizeof (int),
 824                 .mode           = 0444,
 825                 .proc_handler   = proc_dointvec,
 826         },
 827         {
 828                 .procname       = "cap_last_cap",
 829                 .data           = (void *)&cap_last_cap,
 830                 .maxlen         = sizeof(int),
 831                 .mode           = 0444,
 832                 .proc_handler   = proc_dointvec,
 833         },
 834 #if defined(CONFIG_LOCKUP_DETECTOR)
 835         {
 836                 .procname       = "watchdog",
 837                 .data           = &watchdog_user_enabled,
 838                 .maxlen         = sizeof (int),
 839                 .mode           = 0644,
 840                 .proc_handler   = proc_watchdog,
 841                 .extra1         = &zero,
 842                 .extra2         = &one,
 843         },
 844         {
 845                 .procname       = "watchdog_thresh",
 846                 .data           = &watchdog_thresh,
 847                 .maxlen         = sizeof(int),
 848                 .mode           = 0644,
 849                 .proc_handler   = proc_watchdog_thresh,
 850                 .extra1         = &zero,
 851                 .extra2         = &sixty,
 852         },
 853         {
 854                 .procname       = "nmi_watchdog",
 855                 .data           = &nmi_watchdog_enabled,
 856                 .maxlen         = sizeof (int),
 857                 .mode           = 0644,
 858                 .proc_handler   = proc_nmi_watchdog,
 859                 .extra1         = &zero,
 860 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
 861                 .extra2         = &one,
 862 #else
 863                 .extra2         = &zero,
 864 #endif
 865         },
 866         {
 867                 .procname       = "soft_watchdog",
 868                 .data           = &soft_watchdog_enabled,
 869                 .maxlen         = sizeof (int),
 870                 .mode           = 0644,
 871                 .proc_handler   = proc_soft_watchdog,
 872                 .extra1         = &zero,
 873                 .extra2         = &one,
 874         },
 875         {
 876                 .procname       = "watchdog_cpumask",
 877                 .data           = &watchdog_cpumask_bits,
 878                 .maxlen         = NR_CPUS,
 879                 .mode           = 0644,
 880                 .proc_handler   = proc_watchdog_cpumask,
 881         },
 882         {
 883                 .procname       = "softlockup_panic",
 884                 .data           = &softlockup_panic,
 885                 .maxlen         = sizeof(int),
 886                 .mode           = 0644,
 887                 .proc_handler   = proc_dointvec_minmax,
 888                 .extra1         = &zero,
 889                 .extra2         = &one,
 890         },
 891 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 892         {
 893                 .procname       = "hardlockup_panic",
 894                 .data           = &hardlockup_panic,
 895                 .maxlen         = sizeof(int),
 896                 .mode           = 0644,
 897                 .proc_handler   = proc_dointvec_minmax,
 898                 .extra1         = &zero,
 899                 .extra2         = &one,
 900         },
 901 #endif
 902 #ifdef CONFIG_SMP
 903         {
 904                 .procname       = "softlockup_all_cpu_backtrace",
 905                 .data           = &sysctl_softlockup_all_cpu_backtrace,
 906                 .maxlen         = sizeof(int),
 907                 .mode           = 0644,
 908                 .proc_handler   = proc_dointvec_minmax,
 909                 .extra1         = &zero,
 910                 .extra2         = &one,
 911         },
 912         {
 913                 .procname       = "hardlockup_all_cpu_backtrace",
 914                 .data           = &sysctl_hardlockup_all_cpu_backtrace,
 915                 .maxlen         = sizeof(int),
 916                 .mode           = 0644,
 917                 .proc_handler   = proc_dointvec_minmax,
 918                 .extra1         = &zero,
 919                 .extra2         = &one,
 920         },
 921 #endif /* CONFIG_SMP */
 922 #endif
 923 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 924         {
 925                 .procname       = "unknown_nmi_panic",
 926                 .data           = &unknown_nmi_panic,
 927                 .maxlen         = sizeof (int),
 928                 .mode           = 0644,
 929                 .proc_handler   = proc_dointvec,
 930         },
 931 #endif
 932 #if defined(CONFIG_X86)
 933         {
 934                 .procname       = "panic_on_unrecovered_nmi",
 935                 .data           = &panic_on_unrecovered_nmi,
 936                 .maxlen         = sizeof(int),
 937                 .mode           = 0644,
 938                 .proc_handler   = proc_dointvec,
 939         },
 940         {
 941                 .procname       = "panic_on_io_nmi",
 942                 .data           = &panic_on_io_nmi,
 943                 .maxlen         = sizeof(int),
 944                 .mode           = 0644,
 945                 .proc_handler   = proc_dointvec,
 946         },
 947 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 948         {
 949                 .procname       = "panic_on_stackoverflow",
 950                 .data           = &sysctl_panic_on_stackoverflow,
 951                 .maxlen         = sizeof(int),
 952                 .mode           = 0644,
 953                 .proc_handler   = proc_dointvec,
 954         },
 955 #endif
 956         {
 957                 .procname       = "bootloader_type",
 958                 .data           = &bootloader_type,
 959                 .maxlen         = sizeof (int),
 960                 .mode           = 0444,
 961                 .proc_handler   = proc_dointvec,
 962         },
 963         {
 964                 .procname       = "bootloader_version",
 965                 .data           = &bootloader_version,
 966                 .maxlen         = sizeof (int),
 967                 .mode           = 0444,
 968                 .proc_handler   = proc_dointvec,
 969         },
 970         {
 971                 .procname       = "kstack_depth_to_print",
 972                 .data           = &kstack_depth_to_print,
 973                 .maxlen         = sizeof(int),
 974                 .mode           = 0644,
 975                 .proc_handler   = proc_dointvec,
 976         },
 977         {
 978                 .procname       = "io_delay_type",
 979                 .data           = &io_delay_type,
 980                 .maxlen         = sizeof(int),
 981                 .mode           = 0644,
 982                 .proc_handler   = proc_dointvec,
 983         },
 984 #endif
 985 #if defined(CONFIG_MMU)
 986         {
 987                 .procname       = "randomize_va_space",
 988                 .data           = &randomize_va_space,
 989                 .maxlen         = sizeof(int),
 990                 .mode           = 0644,
 991                 .proc_handler   = proc_dointvec,
 992         },
 993 #endif
 994 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 995         {
 996                 .procname       = "spin_retry",
 997                 .data           = &spin_retry,
 998                 .maxlen         = sizeof (int),
 999                 .mode           = 0644,
1000                 .proc_handler   = proc_dointvec,
1001         },
1002 #endif
1003 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1004         {
1005                 .procname       = "acpi_video_flags",
1006                 .data           = &acpi_realmode_flags,
1007                 .maxlen         = sizeof (unsigned long),
1008                 .mode           = 0644,
1009                 .proc_handler   = proc_doulongvec_minmax,
1010         },
1011 #endif
1012 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1013         {
1014                 .procname       = "ignore-unaligned-usertrap",
1015                 .data           = &no_unaligned_warning,
1016                 .maxlen         = sizeof (int),
1017                 .mode           = 0644,
1018                 .proc_handler   = proc_dointvec,
1019         },
1020 #endif
1021 #ifdef CONFIG_IA64
1022         {
1023                 .procname       = "unaligned-dump-stack",
1024                 .data           = &unaligned_dump_stack,
1025                 .maxlen         = sizeof (int),
1026                 .mode           = 0644,
1027                 .proc_handler   = proc_dointvec,
1028         },
1029 #endif
1030 #ifdef CONFIG_DETECT_HUNG_TASK
1031         {
1032                 .procname       = "hung_task_panic",
1033                 .data           = &sysctl_hung_task_panic,
1034                 .maxlen         = sizeof(int),
1035                 .mode           = 0644,
1036                 .proc_handler   = proc_dointvec_minmax,
1037                 .extra1         = &zero,
1038                 .extra2         = &one,
1039         },
1040         {
1041                 .procname       = "hung_task_check_count",
1042                 .data           = &sysctl_hung_task_check_count,
1043                 .maxlen         = sizeof(int),
1044                 .mode           = 0644,
1045                 .proc_handler   = proc_dointvec_minmax,
1046                 .extra1         = &zero,
1047         },
1048         {
1049                 .procname       = "hung_task_timeout_secs",
1050                 .data           = &sysctl_hung_task_timeout_secs,
1051                 .maxlen         = sizeof(unsigned long),
1052                 .mode           = 0644,
1053                 .proc_handler   = proc_dohung_task_timeout_secs,
1054                 .extra2         = &hung_task_timeout_max,
1055         },
1056         {
1057                 .procname       = "hung_task_warnings",
1058                 .data           = &sysctl_hung_task_warnings,
1059                 .maxlen         = sizeof(int),
1060                 .mode           = 0644,
1061                 .proc_handler   = proc_dointvec_minmax,
1062                 .extra1         = &neg_one,
1063         },
1064 #endif
1065 #ifdef CONFIG_COMPAT
1066         {
1067                 .procname       = "compat-log",
1068                 .data           = &compat_log,
1069                 .maxlen         = sizeof (int),
1070                 .mode           = 0644,
1071                 .proc_handler   = proc_dointvec,
1072         },
1073 #endif
1074 #ifdef CONFIG_RT_MUTEXES
1075         {
1076                 .procname       = "max_lock_depth",
1077                 .data           = &max_lock_depth,
1078                 .maxlen         = sizeof(int),
1079                 .mode           = 0644,
1080                 .proc_handler   = proc_dointvec,
1081         },
1082 #endif
1083         {
1084                 .procname       = "poweroff_cmd",
1085                 .data           = &poweroff_cmd,
1086                 .maxlen         = POWEROFF_CMD_PATH_LEN,
1087                 .mode           = 0644,
1088                 .proc_handler   = proc_dostring,
1089         },
1090 #ifdef CONFIG_KEYS
1091         {
1092                 .procname       = "keys",
1093                 .mode           = 0555,
1094                 .child          = key_sysctls,
1095         },
1096 #endif
1097 #ifdef CONFIG_PERF_EVENTS
1098         /*
1099          * User-space scripts rely on the existence of this file
1100          * as a feature check for perf_events being enabled.
1101          *
1102          * So it's an ABI, do not remove!
1103          */
1104         {
1105                 .procname       = "perf_event_paranoid",
1106                 .data           = &sysctl_perf_event_paranoid,
1107                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
1108                 .mode           = 0644,
1109                 .proc_handler   = proc_dointvec,
1110         },
1111         {
1112                 .procname       = "perf_event_mlock_kb",
1113                 .data           = &sysctl_perf_event_mlock,
1114                 .maxlen         = sizeof(sysctl_perf_event_mlock),
1115                 .mode           = 0644,
1116                 .proc_handler   = proc_dointvec,
1117         },
1118         {
1119                 .procname       = "perf_event_max_sample_rate",
1120                 .data           = &sysctl_perf_event_sample_rate,
1121                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
1122                 .mode           = 0644,
1123                 .proc_handler   = perf_proc_update_handler,
1124                 .extra1         = &one,
1125         },
1126         {
1127                 .procname       = "perf_cpu_time_max_percent",
1128                 .data           = &sysctl_perf_cpu_time_max_percent,
1129                 .maxlen         = sizeof(sysctl_perf_cpu_time_max_percent),
1130                 .mode           = 0644,
1131                 .proc_handler   = perf_cpu_time_max_percent_handler,
1132                 .extra1         = &zero,
1133                 .extra2         = &one_hundred,
1134         },
1135 #endif
1136 #ifdef CONFIG_KMEMCHECK
1137         {
1138                 .procname       = "kmemcheck",
1139                 .data           = &kmemcheck_enabled,
1140                 .maxlen         = sizeof(int),
1141                 .mode           = 0644,
1142                 .proc_handler   = proc_dointvec,
1143         },
1144 #endif
1145         {
1146                 .procname       = "panic_on_warn",
1147                 .data           = &panic_on_warn,
1148                 .maxlen         = sizeof(int),
1149                 .mode           = 0644,
1150                 .proc_handler   = proc_dointvec_minmax,
1151                 .extra1         = &zero,
1152                 .extra2         = &one,
1153         },
1154 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1155         {
1156                 .procname       = "timer_migration",
1157                 .data           = &sysctl_timer_migration,
1158                 .maxlen         = sizeof(unsigned int),
1159                 .mode           = 0644,
1160                 .proc_handler   = timer_migration_handler,
1161         },
1162 #endif
1163 #ifdef CONFIG_BPF_SYSCALL
1164         {
1165                 .procname       = "unprivileged_bpf_disabled",
1166                 .data           = &sysctl_unprivileged_bpf_disabled,
1167                 .maxlen         = sizeof(sysctl_unprivileged_bpf_disabled),
1168                 .mode           = 0644,
1169                 /* only handle a transition from default "0" to "1" */
1170                 .proc_handler   = proc_dointvec_minmax,
1171                 .extra1         = &one,
1172                 .extra2         = &one,
1173         },
1174 #endif
1175         { }
1176 };
1177
1178 static struct ctl_table vm_table[] = {
1179         {
1180                 .procname       = "overcommit_memory",
1181                 .data           = &sysctl_overcommit_memory,
1182                 .maxlen         = sizeof(sysctl_overcommit_memory),
1183                 .mode           = 0644,
1184                 .proc_handler   = proc_dointvec_minmax,
1185                 .extra1         = &zero,
1186                 .extra2         = &two,
1187         },
1188         {
1189                 .procname       = "panic_on_oom",
1190                 .data           = &sysctl_panic_on_oom,
1191                 .maxlen         = sizeof(sysctl_panic_on_oom),
1192                 .mode           = 0644,
1193                 .proc_handler   = proc_dointvec_minmax,
1194                 .extra1         = &zero,
1195                 .extra2         = &two,
1196         },
1197         {
1198                 .procname       = "oom_kill_allocating_task",
1199                 .data           = &sysctl_oom_kill_allocating_task,
1200                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1201                 .mode           = 0644,
1202                 .proc_handler   = proc_dointvec,
1203         },
1204         {
1205                 .procname       = "oom_dump_tasks",
1206                 .data           = &sysctl_oom_dump_tasks,
1207                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1208                 .mode           = 0644,
1209                 .proc_handler   = proc_dointvec,
1210         },
1211         {
1212                 .procname       = "overcommit_ratio",
1213                 .data           = &sysctl_overcommit_ratio,
1214                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1215                 .mode           = 0644,
1216                 .proc_handler   = overcommit_ratio_handler,
1217         },
1218         {
1219                 .procname       = "overcommit_kbytes",
1220                 .data           = &sysctl_overcommit_kbytes,
1221                 .maxlen         = sizeof(sysctl_overcommit_kbytes),
1222                 .mode           = 0644,
1223                 .proc_handler   = overcommit_kbytes_handler,
1224         },
1225         {
1226                 .procname       = "page-cluster",
1227                 .data           = &page_cluster,
1228                 .maxlen         = sizeof(int),
1229                 .mode           = 0644,
1230                 .proc_handler   = proc_dointvec_minmax,
1231                 .extra1         = &zero,
1232         },
1233         {
1234                 .procname       = "dirty_background_ratio",
1235                 .data           = &dirty_background_ratio,
1236                 .maxlen         = sizeof(dirty_background_ratio),
1237                 .mode           = 0644,
1238                 .proc_handler   = dirty_background_ratio_handler,
1239                 .extra1         = &zero,
1240                 .extra2         = &one_hundred,
1241         },
1242         {
1243                 .procname       = "dirty_background_bytes",
1244                 .data           = &dirty_background_bytes,
1245                 .maxlen         = sizeof(dirty_background_bytes),
1246                 .mode           = 0644,
1247                 .proc_handler   = dirty_background_bytes_handler,
1248                 .extra1         = &one_ul,
1249         },
1250         {
1251                 .procname       = "dirty_ratio",
1252                 .data           = &vm_dirty_ratio,
1253                 .maxlen         = sizeof(vm_dirty_ratio),
1254                 .mode           = 0644,
1255                 .proc_handler   = dirty_ratio_handler,
1256                 .extra1         = &zero,
1257                 .extra2         = &one_hundred,
1258         },
1259         {
1260                 .procname       = "dirty_bytes",
1261                 .data           = &vm_dirty_bytes,
1262                 .maxlen         = sizeof(vm_dirty_bytes),
1263                 .mode           = 0644,
1264                 .proc_handler   = dirty_bytes_handler,
1265                 .extra1         = &dirty_bytes_min,
1266         },
1267         {
1268                 .procname       = "dirty_writeback_centisecs",
1269                 .data           = &dirty_writeback_interval,
1270                 .maxlen         = sizeof(dirty_writeback_interval),
1271                 .mode           = 0644,
1272                 .proc_handler   = dirty_writeback_centisecs_handler,
1273         },
1274         {
1275                 .procname       = "dirty_expire_centisecs",
1276                 .data           = &dirty_expire_interval,
1277                 .maxlen         = sizeof(dirty_expire_interval),
1278                 .mode           = 0644,
1279                 .proc_handler   = proc_dointvec_minmax,
1280                 .extra1         = &zero,
1281         },
1282         {
1283                 .procname       = "dirtytime_expire_seconds",
1284                 .data           = &dirtytime_expire_interval,
1285                 .maxlen         = sizeof(dirty_expire_interval),
1286                 .mode           = 0644,
1287                 .proc_handler   = dirtytime_interval_handler,
1288                 .extra1         = &zero,
1289         },
1290         {
1291                 .procname       = "nr_pdflush_threads",
1292                 .mode           = 0444 /* read-only */,
1293                 .proc_handler   = pdflush_proc_obsolete,
1294         },
1295         {
1296                 .procname       = "swappiness",
1297                 .data           = &vm_swappiness,
1298                 .maxlen         = sizeof(vm_swappiness),
1299                 .mode           = 0644,
1300                 .proc_handler   = proc_dointvec_minmax,
1301                 .extra1         = &zero,
1302                 .extra2         = &one_hundred,
1303         },
1304 #ifdef CONFIG_HUGETLB_PAGE
1305         {
1306                 .procname       = "nr_hugepages",
1307                 .data           = NULL,
1308                 .maxlen         = sizeof(unsigned long),
1309                 .mode           = 0644,
1310                 .proc_handler   = hugetlb_sysctl_handler,
1311         },
1312 #ifdef CONFIG_NUMA
1313         {
1314                 .procname       = "nr_hugepages_mempolicy",
1315                 .data           = NULL,
1316                 .maxlen         = sizeof(unsigned long),
1317                 .mode           = 0644,
1318                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1319         },
1320 #endif
1321          {
1322                 .procname       = "hugetlb_shm_group",
1323                 .data           = &sysctl_hugetlb_shm_group,
1324                 .maxlen         = sizeof(gid_t),
1325                 .mode           = 0644,
1326                 .proc_handler   = proc_dointvec,
1327          },
1328          {
1329                 .procname       = "hugepages_treat_as_movable",
1330                 .data           = &hugepages_treat_as_movable,
1331                 .maxlen         = sizeof(int),
1332                 .mode           = 0644,
1333                 .proc_handler   = proc_dointvec,
1334         },
1335         {
1336                 .procname       = "nr_overcommit_hugepages",
1337                 .data           = NULL,
1338                 .maxlen         = sizeof(unsigned long),
1339                 .mode           = 0644,
1340                 .proc_handler   = hugetlb_overcommit_handler,
1341         },
1342 #endif
1343         {
1344                 .procname       = "lowmem_reserve_ratio",
1345                 .data           = &sysctl_lowmem_reserve_ratio,
1346                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1347                 .mode           = 0644,
1348                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1349         },
1350         {
1351                 .procname       = "drop_caches",
1352                 .data           = &sysctl_drop_caches,
1353                 .maxlen         = sizeof(int),
1354                 .mode           = 0644,
1355                 .proc_handler   = drop_caches_sysctl_handler,
1356                 .extra1         = &one,
1357                 .extra2         = &four,
1358         },
1359 #ifdef CONFIG_COMPACTION
1360         {
1361                 .procname       = "compact_memory",
1362                 .data           = &sysctl_compact_memory,
1363                 .maxlen         = sizeof(int),
1364                 .mode           = 0200,
1365                 .proc_handler   = sysctl_compaction_handler,
1366         },
1367         {
1368                 .procname       = "extfrag_threshold",
1369                 .data           = &sysctl_extfrag_threshold,
1370                 .maxlen         = sizeof(int),
1371                 .mode           = 0644,
1372                 .proc_handler   = sysctl_extfrag_handler,
1373                 .extra1         = &min_extfrag_threshold,
1374                 .extra2         = &max_extfrag_threshold,
1375         },
1376         {
1377                 .procname       = "compact_unevictable_allowed",
1378                 .data           = &sysctl_compact_unevictable_allowed,
1379                 .maxlen         = sizeof(int),
1380                 .mode           = 0644,
1381                 .proc_handler   = proc_dointvec,
1382                 .extra1         = &zero,
1383                 .extra2         = &one,
1384         },
1385
1386 #endif /* CONFIG_COMPACTION */
1387         {
1388                 .procname       = "min_free_kbytes",
1389                 .data           = &min_free_kbytes,
1390                 .maxlen         = sizeof(min_free_kbytes),
1391                 .mode           = 0644,
1392                 .proc_handler   = min_free_kbytes_sysctl_handler,
1393                 .extra1         = &zero,
1394         },
1395         {
1396                 .procname       = "percpu_pagelist_fraction",
1397                 .data           = &percpu_pagelist_fraction,
1398                 .maxlen         = sizeof(percpu_pagelist_fraction),
1399                 .mode           = 0644,
1400                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1401                 .extra1         = &zero,
1402         },
1403 #ifdef CONFIG_MMU
1404         {
1405                 .procname       = "max_map_count",
1406                 .data           = &sysctl_max_map_count,
1407                 .maxlen         = sizeof(sysctl_max_map_count),
1408                 .mode           = 0644,
1409                 .proc_handler   = proc_dointvec_minmax,
1410                 .extra1         = &zero,
1411         },
1412 #else
1413         {
1414                 .procname       = "nr_trim_pages",
1415                 .data           = &sysctl_nr_trim_pages,
1416                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1417                 .mode           = 0644,
1418                 .proc_handler   = proc_dointvec_minmax,
1419                 .extra1         = &zero,
1420         },
1421 #endif
1422         {
1423                 .procname       = "laptop_mode",
1424                 .data           = &laptop_mode,
1425                 .maxlen         = sizeof(laptop_mode),
1426                 .mode           = 0644,
1427                 .proc_handler   = proc_dointvec_jiffies,
1428         },
1429         {
1430                 .procname       = "block_dump",
1431                 .data           = &block_dump,
1432                 .maxlen         = sizeof(block_dump),
1433                 .mode           = 0644,
1434                 .proc_handler   = proc_dointvec,
1435                 .extra1         = &zero,
1436         },
1437         {
1438                 .procname       = "vfs_cache_pressure",
1439                 .data           = &sysctl_vfs_cache_pressure,
1440                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1441                 .mode           = 0644,
1442                 .proc_handler   = proc_dointvec,
1443                 .extra1         = &zero,
1444         },
1445 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1446         {
1447                 .procname       = "legacy_va_layout",
1448                 .data           = &sysctl_legacy_va_layout,
1449                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1450                 .mode           = 0644,
1451                 .proc_handler   = proc_dointvec,
1452                 .extra1         = &zero,
1453         },
1454 #endif
1455 #ifdef CONFIG_NUMA
1456         {
1457                 .procname       = "zone_reclaim_mode",
1458                 .data           = &zone_reclaim_mode,
1459                 .maxlen         = sizeof(zone_reclaim_mode),
1460                 .mode           = 0644,
1461                 .proc_handler   = proc_dointvec,
1462                 .extra1         = &zero,
1463         },
1464         {
1465                 .procname       = "min_unmapped_ratio",
1466                 .data           = &sysctl_min_unmapped_ratio,
1467                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1468                 .mode           = 0644,
1469                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1470                 .extra1         = &zero,
1471                 .extra2         = &one_hundred,
1472         },
1473         {
1474                 .procname       = "min_slab_ratio",
1475                 .data           = &sysctl_min_slab_ratio,
1476                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1477                 .mode           = 0644,
1478                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1479                 .extra1         = &zero,
1480                 .extra2         = &one_hundred,
1481         },
1482 #endif
1483 #ifdef CONFIG_SMP
1484         {
1485                 .procname       = "stat_interval",
1486                 .data           = &sysctl_stat_interval,
1487                 .maxlen         = sizeof(sysctl_stat_interval),
1488                 .mode           = 0644,
1489                 .proc_handler   = proc_dointvec_jiffies,
1490         },
1491 #endif
1492 #ifdef CONFIG_MMU
1493         {
1494                 .procname       = "mmap_min_addr",
1495                 .data           = &dac_mmap_min_addr,
1496                 .maxlen         = sizeof(unsigned long),
1497                 .mode           = 0644,
1498                 .proc_handler   = mmap_min_addr_handler,
1499         },
1500 #endif
1501 #ifdef CONFIG_NUMA
1502         {
1503                 .procname       = "numa_zonelist_order",
1504                 .data           = &numa_zonelist_order,
1505                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1506                 .mode           = 0644,
1507                 .proc_handler   = numa_zonelist_order_handler,
1508         },
1509 #endif
1510 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1511    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1512         {
1513                 .procname       = "vdso_enabled",
1514 #ifdef CONFIG_X86_32
1515                 .data           = &vdso32_enabled,
1516                 .maxlen         = sizeof(vdso32_enabled),
1517 #else
1518                 .data           = &vdso_enabled,
1519                 .maxlen         = sizeof(vdso_enabled),
1520 #endif
1521                 .mode           = 0644,
1522                 .proc_handler   = proc_dointvec,
1523                 .extra1         = &zero,
1524         },
1525 #endif
1526 #ifdef CONFIG_HIGHMEM
1527         {
1528                 .procname       = "highmem_is_dirtyable",
1529                 .data           = &vm_highmem_is_dirtyable,
1530                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1531                 .mode           = 0644,
1532                 .proc_handler   = proc_dointvec_minmax,
1533                 .extra1         = &zero,
1534                 .extra2         = &one,
1535         },
1536 #endif
1537 #ifdef CONFIG_MEMORY_FAILURE
1538         {
1539                 .procname       = "memory_failure_early_kill",
1540                 .data           = &sysctl_memory_failure_early_kill,
1541                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1542                 .mode           = 0644,
1543                 .proc_handler   = proc_dointvec_minmax,
1544                 .extra1         = &zero,
1545                 .extra2         = &one,
1546         },
1547         {
1548                 .procname       = "memory_failure_recovery",
1549                 .data           = &sysctl_memory_failure_recovery,
1550                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1551                 .mode           = 0644,
1552                 .proc_handler   = proc_dointvec_minmax,
1553                 .extra1         = &zero,
1554                 .extra2         = &one,
1555         },
1556 #endif
1557         {
1558                 .procname       = "user_reserve_kbytes",
1559                 .data           = &sysctl_user_reserve_kbytes,
1560                 .maxlen         = sizeof(sysctl_user_reserve_kbytes),
1561                 .mode           = 0644,
1562                 .proc_handler   = proc_doulongvec_minmax,
1563         },
1564         {
1565                 .procname       = "admin_reserve_kbytes",
1566                 .data           = &sysctl_admin_reserve_kbytes,
1567                 .maxlen         = sizeof(sysctl_admin_reserve_kbytes),
1568                 .mode           = 0644,
1569                 .proc_handler   = proc_doulongvec_minmax,
1570         },
1571 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1572         {
1573                 .procname       = "mmap_rnd_bits",
1574                 .data           = &mmap_rnd_bits,
1575                 .maxlen         = sizeof(mmap_rnd_bits),
1576                 .mode           = 0600,
1577                 .proc_handler   = proc_dointvec_minmax,
1578                 .extra1         = (void *)&mmap_rnd_bits_min,
1579                 .extra2         = (void *)&mmap_rnd_bits_max,
1580         },
1581 #endif
1582 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1583         {
1584                 .procname       = "mmap_rnd_compat_bits",
1585                 .data           = &mmap_rnd_compat_bits,
1586                 .maxlen         = sizeof(mmap_rnd_compat_bits),
1587                 .mode           = 0600,
1588                 .proc_handler   = proc_dointvec_minmax,
1589                 .extra1         = (void *)&mmap_rnd_compat_bits_min,
1590                 .extra2         = (void *)&mmap_rnd_compat_bits_max,
1591         },
1592 #endif
1593         { }
1594 };
1595
1596 static struct ctl_table fs_table[] = {
1597         {
1598                 .procname       = "inode-nr",
1599                 .data           = &inodes_stat,
1600                 .maxlen         = 2*sizeof(long),
1601                 .mode           = 0444,
1602                 .proc_handler   = proc_nr_inodes,
1603         },
1604         {
1605                 .procname       = "inode-state",
1606                 .data           = &inodes_stat,
1607                 .maxlen         = 7*sizeof(long),
1608                 .mode           = 0444,
1609                 .proc_handler   = proc_nr_inodes,
1610         },
1611         {
1612                 .procname       = "file-nr",
1613                 .data           = &files_stat,
1614                 .maxlen         = sizeof(files_stat),
1615                 .mode           = 0444,
1616                 .proc_handler   = proc_nr_files,
1617         },
1618         {
1619                 .procname       = "file-max",
1620                 .data           = &files_stat.max_files,
1621                 .maxlen         = sizeof(files_stat.max_files),
1622                 .mode           = 0644,
1623                 .proc_handler   = proc_doulongvec_minmax,
1624         },
1625         {
1626                 .procname       = "nr_open",
1627                 .data           = &sysctl_nr_open,
1628                 .maxlen         = sizeof(int),
1629                 .mode           = 0644,
1630                 .proc_handler   = proc_dointvec_minmax,
1631                 .extra1         = &sysctl_nr_open_min,
1632                 .extra2         = &sysctl_nr_open_max,
1633         },
1634         {
1635                 .procname       = "dentry-state",
1636                 .data           = &dentry_stat,
1637                 .maxlen         = 6*sizeof(long),
1638                 .mode           = 0444,
1639                 .proc_handler   = proc_nr_dentry,
1640         },
1641         {
1642                 .procname       = "overflowuid",
1643                 .data           = &fs_overflowuid,
1644                 .maxlen         = sizeof(int),
1645                 .mode           = 0644,
1646                 .proc_handler   = proc_dointvec_minmax,
1647                 .extra1         = &minolduid,
1648                 .extra2         = &maxolduid,
1649         },
1650         {
1651                 .procname       = "overflowgid",
1652                 .data           = &fs_overflowgid,
1653                 .maxlen         = sizeof(int),
1654                 .mode           = 0644,
1655                 .proc_handler   = proc_dointvec_minmax,
1656                 .extra1         = &minolduid,
1657                 .extra2         = &maxolduid,
1658         },
1659 #ifdef CONFIG_FILE_LOCKING
1660         {
1661                 .procname       = "leases-enable",
1662                 .data           = &leases_enable,
1663                 .maxlen         = sizeof(int),
1664                 .mode           = 0644,
1665                 .proc_handler   = proc_dointvec,
1666         },
1667 #endif
1668 #ifdef CONFIG_DNOTIFY
1669         {
1670                 .procname       = "dir-notify-enable",
1671                 .data           = &dir_notify_enable,
1672                 .maxlen         = sizeof(int),
1673                 .mode           = 0644,
1674                 .proc_handler   = proc_dointvec,
1675         },
1676 #endif
1677 #ifdef CONFIG_MMU
1678 #ifdef CONFIG_FILE_LOCKING
1679         {
1680                 .procname       = "lease-break-time",
1681                 .data           = &lease_break_time,
1682                 .maxlen         = sizeof(int),
1683                 .mode           = 0644,
1684                 .proc_handler   = proc_dointvec,
1685         },
1686 #endif
1687 #ifdef CONFIG_AIO
1688         {
1689                 .procname       = "aio-nr",
1690                 .data           = &aio_nr,
1691                 .maxlen         = sizeof(aio_nr),
1692                 .mode           = 0444,
1693                 .proc_handler   = proc_doulongvec_minmax,
1694         },
1695         {
1696                 .procname       = "aio-max-nr",
1697                 .data           = &aio_max_nr,
1698                 .maxlen         = sizeof(aio_max_nr),
1699                 .mode           = 0644,
1700                 .proc_handler   = proc_doulongvec_minmax,
1701         },
1702 #endif /* CONFIG_AIO */
1703 #ifdef CONFIG_INOTIFY_USER
1704         {
1705                 .procname       = "inotify",
1706                 .mode           = 0555,
1707                 .child          = inotify_table,
1708         },
1709 #endif
1710 #ifdef CONFIG_EPOLL
1711         {
1712                 .procname       = "epoll",
1713                 .mode           = 0555,
1714                 .child          = epoll_table,
1715         },
1716 #endif
1717 #endif
1718         {
1719                 .procname       = "protected_symlinks",
1720                 .data           = &sysctl_protected_symlinks,
1721                 .maxlen         = sizeof(int),
1722                 .mode           = 0600,
1723                 .proc_handler   = proc_dointvec_minmax,
1724                 .extra1         = &zero,
1725                 .extra2         = &one,
1726         },
1727         {
1728                 .procname       = "protected_hardlinks",
1729                 .data           = &sysctl_protected_hardlinks,
1730                 .maxlen         = sizeof(int),
1731                 .mode           = 0600,
1732                 .proc_handler   = proc_dointvec_minmax,
1733                 .extra1         = &zero,
1734                 .extra2         = &one,
1735         },
1736         {
1737                 .procname       = "suid_dumpable",
1738                 .data           = &suid_dumpable,
1739                 .maxlen         = sizeof(int),
1740                 .mode           = 0644,
1741                 .proc_handler   = proc_dointvec_minmax_coredump,
1742                 .extra1         = &zero,
1743                 .extra2         = &two,
1744         },
1745 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1746         {
1747                 .procname       = "binfmt_misc",
1748                 .mode           = 0555,
1749                 .child          = sysctl_mount_point,
1750         },
1751 #endif
1752         {
1753                 .procname       = "pipe-max-size",
1754                 .data           = &pipe_max_size,
1755                 .maxlen         = sizeof(int),
1756                 .mode           = 0644,
1757                 .proc_handler   = &pipe_proc_fn,
1758                 .extra1         = &pipe_min_size,
1759         },
1760         {
1761                 .procname       = "pipe-user-pages-hard",
1762                 .data           = &pipe_user_pages_hard,
1763                 .maxlen         = sizeof(pipe_user_pages_hard),
1764                 .mode           = 0644,
1765                 .proc_handler   = proc_doulongvec_minmax,
1766         },
1767         {
1768                 .procname       = "pipe-user-pages-soft",
1769                 .data           = &pipe_user_pages_soft,
1770                 .maxlen         = sizeof(pipe_user_pages_soft),
1771                 .mode           = 0644,
1772                 .proc_handler   = proc_doulongvec_minmax,
1773         },
1774         { }
1775 };
1776
1777 static struct ctl_table debug_table[] = {
1778 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1779         {
1780                 .procname       = "exception-trace",
1781                 .data           = &show_unhandled_signals,
1782                 .maxlen         = sizeof(int),
1783                 .mode           = 0644,
1784                 .proc_handler   = proc_dointvec
1785         },
1786 #endif
1787 #if defined(CONFIG_OPTPROBES)
1788         {
1789                 .procname       = "kprobes-optimization",
1790                 .data           = &sysctl_kprobes_optimization,
1791                 .maxlen         = sizeof(int),
1792                 .mode           = 0644,
1793                 .proc_handler   = proc_kprobes_optimization_handler,
1794                 .extra1         = &zero,
1795                 .extra2         = &one,
1796         },
1797 #endif
1798         { }
1799 };
1800
1801 static struct ctl_table dev_table[] = {
1802         { }
1803 };
1804
1805 int __init sysctl_init(void)
1806 {
1807         struct ctl_table_header *hdr;
1808
1809         hdr = register_sysctl_table(sysctl_base_table);
1810         kmemleak_not_leak(hdr);
1811         return 0;
1812 }
1813
1814 #endif /* CONFIG_SYSCTL */
1815
1816 /*
1817  * /proc/sys support
1818  */
1819
1820 #ifdef CONFIG_PROC_SYSCTL
1821
1822 static int _proc_do_string(char *data, int maxlen, int write,
1823                            char __user *buffer,
1824                            size_t *lenp, loff_t *ppos)
1825 {
1826         size_t len;
1827         char __user *p;
1828         char c;
1829
1830         if (!data || !maxlen || !*lenp) {
1831                 *lenp = 0;
1832                 return 0;
1833         }
1834
1835         if (write) {
1836                 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1837                         /* Only continue writes not past the end of buffer. */
1838                         len = strlen(data);
1839                         if (len > maxlen - 1)
1840                                 len = maxlen - 1;
1841
1842                         if (*ppos > len)
1843                                 return 0;
1844                         len = *ppos;
1845                 } else {
1846                         /* Start writing from beginning of buffer. */
1847                         len = 0;
1848                 }
1849
1850                 *ppos += *lenp;
1851                 p = buffer;
1852                 while ((p - buffer) < *lenp && len < maxlen - 1) {
1853                         if (get_user(c, p++))
1854                                 return -EFAULT;
1855                         if (c == 0 || c == '\n')
1856                                 break;
1857                         data[len++] = c;
1858                 }
1859                 data[len] = 0;
1860         } else {
1861                 len = strlen(data);
1862                 if (len > maxlen)
1863                         len = maxlen;
1864
1865                 if (*ppos > len) {
1866                         *lenp = 0;
1867                         return 0;
1868                 }
1869
1870                 data += *ppos;
1871                 len  -= *ppos;
1872
1873                 if (len > *lenp)
1874                         len = *lenp;
1875                 if (len)
1876                         if (copy_to_user(buffer, data, len))
1877                                 return -EFAULT;
1878                 if (len < *lenp) {
1879                         if (put_user('\n', buffer + len))
1880                                 return -EFAULT;
1881                         len++;
1882                 }
1883                 *lenp = len;
1884                 *ppos += len;
1885         }
1886         return 0;
1887 }
1888
1889 static void warn_sysctl_write(struct ctl_table *table)
1890 {
1891         pr_warn_once("%s wrote to %s when file position was not 0!\n"
1892                 "This will not be supported in the future. To silence this\n"
1893                 "warning, set kernel.sysctl_writes_strict = -1\n",
1894                 current->comm, table->procname);
1895 }
1896
1897 /**
1898  * proc_dostring - read a string sysctl
1899  * @table: the sysctl table
1900  * @write: %TRUE if this is a write to the sysctl file
1901  * @buffer: the user buffer
1902  * @lenp: the size of the user buffer
1903  * @ppos: file position
1904  *
1905  * Reads/writes a string from/to the user buffer. If the kernel
1906  * buffer provided is not large enough to hold the string, the
1907  * string is truncated. The copied string is %NULL-terminated.
1908  * If the string is being read by the user process, it is copied
1909  * and a newline '\n' is added. It is truncated if the buffer is
1910  * not large enough.
1911  *
1912  * Returns 0 on success.
1913  */
1914 int proc_dostring(struct ctl_table *table, int write,
1915                   void __user *buffer, size_t *lenp, loff_t *ppos)
1916 {
1917         if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1918                 warn_sysctl_write(table);
1919
1920         return _proc_do_string((char *)(table->data), table->maxlen, write,
1921                                (char __user *)buffer, lenp, ppos);
1922 }
1923
1924 static size_t proc_skip_spaces(char **buf)
1925 {
1926         size_t ret;
1927         char *tmp = skip_spaces(*buf);
1928         ret = tmp - *buf;
1929         *buf = tmp;
1930         return ret;
1931 }
1932
1933 static void proc_skip_char(char **buf, size_t *size, const char v)
1934 {
1935         while (*size) {
1936                 if (**buf != v)
1937                         break;
1938                 (*size)--;
1939                 (*buf)++;
1940         }
1941 }
1942
1943 #define TMPBUFLEN 22
1944 /**
1945  * proc_get_long - reads an ASCII formatted integer from a user buffer
1946  *
1947  * @buf: a kernel buffer
1948  * @size: size of the kernel buffer
1949  * @val: this is where the number will be stored
1950  * @neg: set to %TRUE if number is negative
1951  * @perm_tr: a vector which contains the allowed trailers
1952  * @perm_tr_len: size of the perm_tr vector
1953  * @tr: pointer to store the trailer character
1954  *
1955  * In case of success %0 is returned and @buf and @size are updated with
1956  * the amount of bytes read. If @tr is non-NULL and a trailing
1957  * character exists (size is non-zero after returning from this
1958  * function), @tr is updated with the trailing character.
1959  */
1960 static int proc_get_long(char **buf, size_t *size,
1961                           unsigned long *val, bool *neg,
1962                           const char *perm_tr, unsigned perm_tr_len, char *tr)
1963 {
1964         int len;
1965         char *p, tmp[TMPBUFLEN];
1966
1967         if (!*size)
1968                 return -EINVAL;
1969
1970         len = *size;
1971         if (len > TMPBUFLEN - 1)
1972                 len = TMPBUFLEN - 1;
1973
1974         memcpy(tmp, *buf, len);
1975
1976         tmp[len] = 0;
1977         p = tmp;
1978         if (*p == '-' && *size > 1) {
1979                 *neg = true;
1980                 p++;
1981         } else
1982                 *neg = false;
1983         if (!isdigit(*p))
1984                 return -EINVAL;
1985
1986         *val = simple_strtoul(p, &p, 0);
1987
1988         len = p - tmp;
1989
1990         /* We don't know if the next char is whitespace thus we may accept
1991          * invalid integers (e.g. 1234...a) or two integers instead of one
1992          * (e.g. 123...1). So lets not allow such large numbers. */
1993         if (len == TMPBUFLEN - 1)
1994                 return -EINVAL;
1995
1996         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
1997                 return -EINVAL;
1998
1999         if (tr && (len < *size))
2000                 *tr = *p;
2001
2002         *buf += len;
2003         *size -= len;
2004
2005         return 0;
2006 }
2007
2008 /**
2009  * proc_put_long - converts an integer to a decimal ASCII formatted string
2010  *
2011  * @buf: the user buffer
2012  * @size: the size of the user buffer
2013  * @val: the integer to be converted
2014  * @neg: sign of the number, %TRUE for negative
2015  *
2016  * In case of success %0 is returned and @buf and @size are updated with
2017  * the amount of bytes written.
2018  */
2019 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2020                           bool neg)
2021 {
2022         int len;
2023         char tmp[TMPBUFLEN], *p = tmp;
2024
2025         sprintf(p, "%s%lu", neg ? "-" : "", val);
2026         len = strlen(tmp);
2027         if (len > *size)
2028                 len = *size;
2029         if (copy_to_user(*buf, tmp, len))
2030                 return -EFAULT;
2031         *size -= len;
2032         *buf += len;
2033         return 0;
2034 }
2035 #undef TMPBUFLEN
2036
2037 static int proc_put_char(void __user **buf, size_t *size, char c)
2038 {
2039         if (*size) {
2040                 char __user **buffer = (char __user **)buf;
2041                 if (put_user(c, *buffer))
2042                         return -EFAULT;
2043                 (*size)--, (*buffer)++;
2044                 *buf = *buffer;
2045         }
2046         return 0;
2047 }
2048
2049 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2050                                  int *valp,
2051                                  int write, void *data)
2052 {
2053         if (write) {
2054                 if (*negp) {
2055                         if (*lvalp > (unsigned long) INT_MAX + 1)
2056                                 return -EINVAL;
2057                         *valp = -*lvalp;
2058                 } else {
2059                         if (*lvalp > (unsigned long) INT_MAX)
2060                                 return -EINVAL;
2061                         *valp = *lvalp;
2062                 }
2063         } else {
2064                 int val = *valp;
2065                 if (val < 0) {
2066                         *negp = true;
2067                         *lvalp = -(unsigned long)val;
2068                 } else {
2069                         *negp = false;
2070                         *lvalp = (unsigned long)val;
2071                 }
2072         }
2073         return 0;
2074 }
2075
2076 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2077
2078 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2079                   int write, void __user *buffer,
2080                   size_t *lenp, loff_t *ppos,
2081                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2082                               int write, void *data),
2083                   void *data)
2084 {
2085         int *i, vleft, first = 1, err = 0;
2086         size_t left;
2087         char *kbuf = NULL, *p;
2088
2089         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2090                 *lenp = 0;
2091                 return 0;
2092         }
2093
2094         i = (int *) tbl_data;
2095         vleft = table->maxlen / sizeof(*i);
2096         left = *lenp;
2097
2098         if (!conv)
2099                 conv = do_proc_dointvec_conv;
2100
2101         if (write) {
2102                 if (*ppos) {
2103                         switch (sysctl_writes_strict) {
2104                         case SYSCTL_WRITES_STRICT:
2105                                 goto out;
2106                         case SYSCTL_WRITES_WARN:
2107                                 warn_sysctl_write(table);
2108                                 break;
2109                         default:
2110                                 break;
2111                         }
2112                 }
2113
2114                 if (left > PAGE_SIZE - 1)
2115                         left = PAGE_SIZE - 1;
2116                 p = kbuf = memdup_user_nul(buffer, left);
2117                 if (IS_ERR(kbuf))
2118                         return PTR_ERR(kbuf);
2119         }
2120
2121         for (; left && vleft--; i++, first=0) {
2122                 unsigned long lval;
2123                 bool neg;
2124
2125                 if (write) {
2126                         left -= proc_skip_spaces(&p);
2127
2128                         if (!left)
2129                                 break;
2130                         err = proc_get_long(&p, &left, &lval, &neg,
2131                                              proc_wspace_sep,
2132                                              sizeof(proc_wspace_sep), NULL);
2133                         if (err)
2134                                 break;
2135                         if (conv(&neg, &lval, i, 1, data)) {
2136                                 err = -EINVAL;
2137                                 break;
2138                         }
2139                 } else {
2140                         if (conv(&neg, &lval, i, 0, data)) {
2141                                 err = -EINVAL;
2142                                 break;
2143                         }
2144                         if (!first)
2145                                 err = proc_put_char(&buffer, &left, '\t');
2146                         if (err)
2147                                 break;
2148                         err = proc_put_long(&buffer, &left, lval, neg);
2149                         if (err)
2150                                 break;
2151                 }
2152         }
2153
2154         if (!write && !first && left && !err)
2155                 err = proc_put_char(&buffer, &left, '\n');
2156         if (write && !err && left)
2157                 left -= proc_skip_spaces(&p);
2158         if (write) {
2159                 kfree(kbuf);
2160                 if (first)
2161                         return err ? : -EINVAL;
2162         }
2163         *lenp -= left;
2164 out:
2165         *ppos += *lenp;
2166         return err;
2167 }
2168
2169 static int do_proc_dointvec(struct ctl_table *table, int write,
2170                   void __user *buffer, size_t *lenp, loff_t *ppos,
2171                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2172                               int write, void *data),
2173                   void *data)
2174 {
2175         return __do_proc_dointvec(table->data, table, write,
2176                         buffer, lenp, ppos, conv, data);
2177 }
2178
2179 /**
2180  * proc_dointvec - read a vector of integers
2181  * @table: the sysctl table
2182  * @write: %TRUE if this is a write to the sysctl file
2183  * @buffer: the user buffer
2184  * @lenp: the size of the user buffer
2185  * @ppos: file position
2186  *
2187  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2188  * values from/to the user buffer, treated as an ASCII string.
2189  *
2190  * Returns 0 on success.
2191  */
2192 int proc_dointvec(struct ctl_table *table, int write,
2193                      void __user *buffer, size_t *lenp, loff_t *ppos)
2194 {
2195     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2196                             NULL,NULL);
2197 }
2198
2199 /*
2200  * Taint values can only be increased
2201  * This means we can safely use a temporary.
2202  */
2203 static int proc_taint(struct ctl_table *table, int write,
2204                                void __user *buffer, size_t *lenp, loff_t *ppos)
2205 {
2206         struct ctl_table t;
2207         unsigned long tmptaint = get_taint();
2208         int err;
2209
2210         if (write && !capable(CAP_SYS_ADMIN))
2211                 return -EPERM;
2212
2213         t = *table;
2214         t.data = &tmptaint;
2215         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2216         if (err < 0)
2217                 return err;
2218
2219         if (write) {
2220                 /*
2221                  * Poor man's atomic or. Not worth adding a primitive
2222                  * to everyone's atomic.h for this
2223                  */
2224                 int i;
2225                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2226                         if ((tmptaint >> i) & 1)
2227                                 add_taint(i, LOCKDEP_STILL_OK);
2228                 }
2229         }
2230
2231         return err;
2232 }
2233
2234 #ifdef CONFIG_PRINTK
2235 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2236                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2237 {
2238         if (write && !capable(CAP_SYS_ADMIN))
2239                 return -EPERM;
2240
2241         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2242 }
2243 #endif
2244
2245 struct do_proc_dointvec_minmax_conv_param {
2246         int *min;
2247         int *max;
2248 };
2249
2250 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2251                                         int *valp,
2252                                         int write, void *data)
2253 {
2254         struct do_proc_dointvec_minmax_conv_param *param = data;
2255         if (write) {
2256                 int val = *negp ? -*lvalp : *lvalp;
2257                 if ((param->min && *param->min > val) ||
2258                     (param->max && *param->max < val))
2259                         return -EINVAL;
2260                 *valp = val;
2261         } else {
2262                 int val = *valp;
2263                 if (val < 0) {
2264                         *negp = true;
2265                         *lvalp = -(unsigned long)val;
2266                 } else {
2267                         *negp = false;
2268                         *lvalp = (unsigned long)val;
2269                 }
2270         }
2271         return 0;
2272 }
2273
2274 /**
2275  * proc_dointvec_minmax - read a vector of integers with min/max values
2276  * @table: the sysctl table
2277  * @write: %TRUE if this is a write to the sysctl file
2278  * @buffer: the user buffer
2279  * @lenp: the size of the user buffer
2280  * @ppos: file position
2281  *
2282  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2283  * values from/to the user buffer, treated as an ASCII string.
2284  *
2285  * This routine will ensure the values are within the range specified by
2286  * table->extra1 (min) and table->extra2 (max).
2287  *
2288  * Returns 0 on success.
2289  */
2290 int proc_dointvec_minmax(struct ctl_table *table, int write,
2291                   void __user *buffer, size_t *lenp, loff_t *ppos)
2292 {
2293         struct do_proc_dointvec_minmax_conv_param param = {
2294                 .min = (int *) table->extra1,
2295                 .max = (int *) table->extra2,
2296         };
2297         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2298                                 do_proc_dointvec_minmax_conv, &param);
2299 }
2300
2301 static void validate_coredump_safety(void)
2302 {
2303 #ifdef CONFIG_COREDUMP
2304         if (suid_dumpable == SUID_DUMP_ROOT &&
2305             core_pattern[0] != '/' && core_pattern[0] != '|') {
2306                 printk(KERN_WARNING "Unsafe core_pattern used with "\
2307                         "suid_dumpable=2. Pipe handler or fully qualified "\
2308                         "core dump path required.\n");
2309         }
2310 #endif
2311 }
2312
2313 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2314                 void __user *buffer, size_t *lenp, loff_t *ppos)
2315 {
2316         int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2317         if (!error)
2318                 validate_coredump_safety();
2319         return error;
2320 }
2321
2322 #ifdef CONFIG_COREDUMP
2323 static int proc_dostring_coredump(struct ctl_table *table, int write,
2324                   void __user *buffer, size_t *lenp, loff_t *ppos)
2325 {
2326         int error = proc_dostring(table, write, buffer, lenp, ppos);
2327         if (!error)
2328                 validate_coredump_safety();
2329         return error;
2330 }
2331 #endif
2332
2333 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2334                                      void __user *buffer,
2335                                      size_t *lenp, loff_t *ppos,
2336                                      unsigned long convmul,
2337                                      unsigned long convdiv)
2338 {
2339         unsigned long *i, *min, *max;
2340         int vleft, first = 1, err = 0;
2341         size_t left;
2342         char *kbuf = NULL, *p;
2343
2344         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2345                 *lenp = 0;
2346                 return 0;
2347         }
2348
2349         i = (unsigned long *) data;
2350         min = (unsigned long *) table->extra1;
2351         max = (unsigned long *) table->extra2;
2352         vleft = table->maxlen / sizeof(unsigned long);
2353         left = *lenp;
2354
2355         if (write) {
2356                 if (*ppos) {
2357                         switch (sysctl_writes_strict) {
2358                         case SYSCTL_WRITES_STRICT:
2359                                 goto out;
2360                         case SYSCTL_WRITES_WARN:
2361                                 warn_sysctl_write(table);
2362                                 break;
2363                         default:
2364                                 break;
2365                         }
2366                 }
2367
2368                 if (left > PAGE_SIZE - 1)
2369                         left = PAGE_SIZE - 1;
2370                 p = kbuf = memdup_user_nul(buffer, left);
2371                 if (IS_ERR(kbuf))
2372                         return PTR_ERR(kbuf);
2373         }
2374
2375         for (; left && vleft--; i++, first = 0) {
2376                 unsigned long val;
2377
2378                 if (write) {
2379                         bool neg;
2380
2381                         left -= proc_skip_spaces(&p);
2382
2383                         err = proc_get_long(&p, &left, &val, &neg,
2384                                              proc_wspace_sep,
2385                                              sizeof(proc_wspace_sep), NULL);
2386                         if (err)
2387                                 break;
2388                         if (neg)
2389                                 continue;
2390                         if ((min && val < *min) || (max && val > *max))
2391                                 continue;
2392                         *i = val;
2393                 } else {
2394                         val = convdiv * (*i) / convmul;
2395                         if (!first) {
2396                                 err = proc_put_char(&buffer, &left, '\t');
2397                                 if (err)
2398                                         break;
2399                         }
2400                         err = proc_put_long(&buffer, &left, val, false);
2401                         if (err)
2402                                 break;
2403                 }
2404         }
2405
2406         if (!write && !first && left && !err)
2407                 err = proc_put_char(&buffer, &left, '\n');
2408         if (write && !err)
2409                 left -= proc_skip_spaces(&p);
2410         if (write) {
2411                 kfree(kbuf);
2412                 if (first)
2413                         return err ? : -EINVAL;
2414         }
2415         *lenp -= left;
2416 out:
2417         *ppos += *lenp;
2418         return err;
2419 }
2420
2421 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2422                                      void __user *buffer,
2423                                      size_t *lenp, loff_t *ppos,
2424                                      unsigned long convmul,
2425                                      unsigned long convdiv)
2426 {
2427         return __do_proc_doulongvec_minmax(table->data, table, write,
2428                         buffer, lenp, ppos, convmul, convdiv);
2429 }
2430
2431 /**
2432  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2433  * @table: the sysctl table
2434  * @write: %TRUE if this is a write to the sysctl file
2435  * @buffer: the user buffer
2436  * @lenp: the size of the user buffer
2437  * @ppos: file position
2438  *
2439  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2440  * values from/to the user buffer, treated as an ASCII string.
2441  *
2442  * This routine will ensure the values are within the range specified by
2443  * table->extra1 (min) and table->extra2 (max).
2444  *
2445  * Returns 0 on success.
2446  */
2447 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2448                            void __user *buffer, size_t *lenp, loff_t *ppos)
2449 {
2450     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2451 }
2452
2453 /**
2454  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2455  * @table: the sysctl table
2456  * @write: %TRUE if this is a write to the sysctl file
2457  * @buffer: the user buffer
2458  * @lenp: the size of the user buffer
2459  * @ppos: file position
2460  *
2461  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2462  * values from/to the user buffer, treated as an ASCII string. The values
2463  * are treated as milliseconds, and converted to jiffies when they are stored.
2464  *
2465  * This routine will ensure the values are within the range specified by
2466  * table->extra1 (min) and table->extra2 (max).
2467  *
2468  * Returns 0 on success.
2469  */
2470 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2471                                       void __user *buffer,
2472                                       size_t *lenp, loff_t *ppos)
2473 {
2474     return do_proc_doulongvec_minmax(table, write, buffer,
2475                                      lenp, ppos, HZ, 1000l);
2476 }
2477
2478
2479 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2480                                          int *valp,
2481                                          int write, void *data)
2482 {
2483         if (write) {
2484                 if (*lvalp > LONG_MAX / HZ)
2485                         return 1;
2486                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2487         } else {
2488                 int val = *valp;
2489                 unsigned long lval;
2490                 if (val < 0) {
2491                         *negp = true;
2492                         lval = -(unsigned long)val;
2493                 } else {
2494                         *negp = false;
2495                         lval = (unsigned long)val;
2496                 }
2497                 *lvalp = lval / HZ;
2498         }
2499         return 0;
2500 }
2501
2502 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2503                                                 int *valp,
2504                                                 int write, void *data)
2505 {
2506         if (write) {
2507                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2508                         return 1;
2509                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2510         } else {
2511                 int val = *valp;
2512                 unsigned long lval;
2513                 if (val < 0) {
2514                         *negp = true;
2515                         lval = -(unsigned long)val;
2516                 } else {
2517                         *negp = false;
2518                         lval = (unsigned long)val;
2519                 }
2520                 *lvalp = jiffies_to_clock_t(lval);
2521         }
2522         return 0;
2523 }
2524
2525 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2526                                             int *valp,
2527                                             int write, void *data)
2528 {
2529         if (write) {
2530                 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2531
2532                 if (jif > INT_MAX)
2533                         return 1;
2534                 *valp = (int)jif;
2535         } else {
2536                 int val = *valp;
2537                 unsigned long lval;
2538                 if (val < 0) {
2539                         *negp = true;
2540                         lval = -(unsigned long)val;
2541                 } else {
2542                         *negp = false;
2543                         lval = (unsigned long)val;
2544                 }
2545                 *lvalp = jiffies_to_msecs(lval);
2546         }
2547         return 0;
2548 }
2549
2550 /**
2551  * proc_dointvec_jiffies - read a vector of integers as seconds
2552  * @table: the sysctl table
2553  * @write: %TRUE if this is a write to the sysctl file
2554  * @buffer: the user buffer
2555  * @lenp: the size of the user buffer
2556  * @ppos: file position
2557  *
2558  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2559  * values from/to the user buffer, treated as an ASCII string.
2560  * The values read are assumed to be in seconds, and are converted into
2561  * jiffies.
2562  *
2563  * Returns 0 on success.
2564  */
2565 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2566                           void __user *buffer, size_t *lenp, loff_t *ppos)
2567 {
2568     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2569                             do_proc_dointvec_jiffies_conv,NULL);
2570 }
2571
2572 /**
2573  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2574  * @table: the sysctl table
2575  * @write: %TRUE if this is a write to the sysctl file
2576  * @buffer: the user buffer
2577  * @lenp: the size of the user buffer
2578  * @ppos: pointer to the file position
2579  *
2580  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2581  * values from/to the user buffer, treated as an ASCII string.
2582  * The values read are assumed to be in 1/USER_HZ seconds, and
2583  * are converted into jiffies.
2584  *
2585  * Returns 0 on success.
2586  */
2587 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2588                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2589 {
2590     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2591                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2592 }
2593
2594 /**
2595  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2596  * @table: the sysctl table
2597  * @write: %TRUE if this is a write to the sysctl file
2598  * @buffer: the user buffer
2599  * @lenp: the size of the user buffer
2600  * @ppos: file position
2601  * @ppos: the current position in the file
2602  *
2603  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2604  * values from/to the user buffer, treated as an ASCII string.
2605  * The values read are assumed to be in 1/1000 seconds, and
2606  * are converted into jiffies.
2607  *
2608  * Returns 0 on success.
2609  */
2610 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2611                              void __user *buffer, size_t *lenp, loff_t *ppos)
2612 {
2613         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2614                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2615 }
2616
2617 static int proc_do_cad_pid(struct ctl_table *table, int write,
2618                            void __user *buffer, size_t *lenp, loff_t *ppos)
2619 {
2620         struct pid *new_pid;
2621         pid_t tmp;
2622         int r;
2623
2624         tmp = pid_vnr(cad_pid);
2625
2626         r = __do_proc_dointvec(&tmp, table, write, buffer,
2627                                lenp, ppos, NULL, NULL);
2628         if (r || !write)
2629                 return r;
2630
2631         new_pid = find_get_pid(tmp);
2632         if (!new_pid)
2633                 return -ESRCH;
2634
2635         put_pid(xchg(&cad_pid, new_pid));
2636         return 0;
2637 }
2638
2639 /**
2640  * proc_do_large_bitmap - read/write from/to a large bitmap
2641  * @table: the sysctl table
2642  * @write: %TRUE if this is a write to the sysctl file
2643  * @buffer: the user buffer
2644  * @lenp: the size of the user buffer
2645  * @ppos: file position
2646  *
2647  * The bitmap is stored at table->data and the bitmap length (in bits)
2648  * in table->maxlen.
2649  *
2650  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2651  * large bitmaps may be represented in a compact manner. Writing into
2652  * the file will clear the bitmap then update it with the given input.
2653  *
2654  * Returns 0 on success.
2655  */
2656 int proc_do_large_bitmap(struct ctl_table *table, int write,
2657                          void __user *buffer, size_t *lenp, loff_t *ppos)
2658 {
2659         int err = 0;
2660         bool first = 1;
2661         size_t left = *lenp;
2662         unsigned long bitmap_len = table->maxlen;
2663         unsigned long *bitmap = *(unsigned long **) table->data;
2664         unsigned long *tmp_bitmap = NULL;
2665         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2666
2667         if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2668                 *lenp = 0;
2669                 return 0;
2670         }
2671
2672         if (write) {
2673                 char *kbuf, *p;
2674
2675                 if (left > PAGE_SIZE - 1)
2676                         left = PAGE_SIZE - 1;
2677
2678                 p = kbuf = memdup_user_nul(buffer, left);
2679                 if (IS_ERR(kbuf))
2680                         return PTR_ERR(kbuf);
2681
2682                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2683                                      GFP_KERNEL);
2684                 if (!tmp_bitmap) {
2685                         kfree(kbuf);
2686                         return -ENOMEM;
2687                 }
2688                 proc_skip_char(&p, &left, '\n');
2689                 while (!err && left) {
2690                         unsigned long val_a, val_b;
2691                         bool neg;
2692
2693                         err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2694                                              sizeof(tr_a), &c);
2695                         if (err)
2696                                 break;
2697                         if (val_a >= bitmap_len || neg) {
2698                                 err = -EINVAL;
2699                                 break;
2700                         }
2701
2702                         val_b = val_a;
2703                         if (left) {
2704                                 p++;
2705                                 left--;
2706                         }
2707
2708                         if (c == '-') {
2709                                 err = proc_get_long(&p, &left, &val_b,
2710                                                      &neg, tr_b, sizeof(tr_b),
2711                                                      &c);
2712                                 if (err)
2713                                         break;
2714                                 if (val_b >= bitmap_len || neg ||
2715                                     val_a > val_b) {
2716                                         err = -EINVAL;
2717                                         break;
2718                                 }
2719                                 if (left) {
2720                                         p++;
2721                                         left--;
2722                                 }
2723                         }
2724
2725                         bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2726                         first = 0;
2727                         proc_skip_char(&p, &left, '\n');
2728                 }
2729                 kfree(kbuf);
2730         } else {
2731                 unsigned long bit_a, bit_b = 0;
2732
2733                 while (left) {
2734                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2735                         if (bit_a >= bitmap_len)
2736                                 break;
2737                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2738                                                    bit_a + 1) - 1;
2739
2740                         if (!first) {
2741                                 err = proc_put_char(&buffer, &left, ',');
2742                                 if (err)
2743                                         break;
2744                         }
2745                         err = proc_put_long(&buffer, &left, bit_a, false);
2746                         if (err)
2747                                 break;
2748                         if (bit_a != bit_b) {
2749                                 err = proc_put_char(&buffer, &left, '-');
2750                                 if (err)
2751                                         break;
2752                                 err = proc_put_long(&buffer, &left, bit_b, false);
2753                                 if (err)
2754                                         break;
2755                         }
2756
2757                         first = 0; bit_b++;
2758                 }
2759                 if (!err)
2760                         err = proc_put_char(&buffer, &left, '\n');
2761         }
2762
2763         if (!err) {
2764                 if (write) {
2765                         if (*ppos)
2766                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2767                         else
2768                                 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2769                 }
2770                 kfree(tmp_bitmap);
2771                 *lenp -= left;
2772                 *ppos += *lenp;
2773                 return 0;
2774         } else {
2775                 kfree(tmp_bitmap);
2776                 return err;
2777         }
2778 }
2779
2780 #else /* CONFIG_PROC_SYSCTL */
2781
2782 int proc_dostring(struct ctl_table *table, int write,
2783                   void __user *buffer, size_t *lenp, loff_t *ppos)
2784 {
2785         return -ENOSYS;
2786 }
2787
2788 int proc_dointvec(struct ctl_table *table, int write,
2789                   void __user *buffer, size_t *lenp, loff_t *ppos)
2790 {
2791         return -ENOSYS;
2792 }
2793
2794 int proc_dointvec_minmax(struct ctl_table *table, int write,
2795                     void __user *buffer, size_t *lenp, loff_t *ppos)
2796 {
2797         return -ENOSYS;
2798 }
2799
2800 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2801                     void __user *buffer, size_t *lenp, loff_t *ppos)
2802 {
2803         return -ENOSYS;
2804 }
2805
2806 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2807                     void __user *buffer, size_t *lenp, loff_t *ppos)
2808 {
2809         return -ENOSYS;
2810 }
2811
2812 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2813                              void __user *buffer, size_t *lenp, loff_t *ppos)
2814 {
2815         return -ENOSYS;
2816 }
2817
2818 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2819                     void __user *buffer, size_t *lenp, loff_t *ppos)
2820 {
2821         return -ENOSYS;
2822 }
2823
2824 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2825                                       void __user *buffer,
2826                                       size_t *lenp, loff_t *ppos)
2827 {
2828     return -ENOSYS;
2829 }
2830
2831
2832 #endif /* CONFIG_PROC_SYSCTL */
2833
2834 /*
2835  * No sense putting this after each symbol definition, twice,
2836  * exception granted :-)
2837  */
2838 EXPORT_SYMBOL(proc_dointvec);
2839 EXPORT_SYMBOL(proc_dointvec_jiffies);
2840 EXPORT_SYMBOL(proc_dointvec_minmax);
2841 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2842 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2843 EXPORT_SYMBOL(proc_dostring);
2844 EXPORT_SYMBOL(proc_doulongvec_minmax);
2845 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);