xref: /linux/kernel/sysctl.c (revision ec2212088c42ff7d1362629ec26dda4f3e8bdad3)
1 /*
2  * sysctl.c: General linux system control interface
3  *
4  * Begun 24 March 1995, Stephen Tweedie
5  * Added /proc support, Dec 1995
6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
9  * Dynamic registration fixes, Stephen Tweedie.
10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
12  *  Horn.
13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
16  *  Wendling.
17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
19  */
20 
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/signal.h>
27 #include <linux/printk.h>
28 #include <linux/proc_fs.h>
29 #include <linux/security.h>
30 #include <linux/ctype.h>
31 #include <linux/kmemcheck.h>
32 #include <linux/fs.h>
33 #include <linux/init.h>
34 #include <linux/kernel.h>
35 #include <linux/kobject.h>
36 #include <linux/net.h>
37 #include <linux/sysrq.h>
38 #include <linux/highuid.h>
39 #include <linux/writeback.h>
40 #include <linux/ratelimit.h>
41 #include <linux/compaction.h>
42 #include <linux/hugetlb.h>
43 #include <linux/initrd.h>
44 #include <linux/key.h>
45 #include <linux/times.h>
46 #include <linux/limits.h>
47 #include <linux/dcache.h>
48 #include <linux/dnotify.h>
49 #include <linux/syscalls.h>
50 #include <linux/vmstat.h>
51 #include <linux/nfs_fs.h>
52 #include <linux/acpi.h>
53 #include <linux/reboot.h>
54 #include <linux/ftrace.h>
55 #include <linux/perf_event.h>
56 #include <linux/kprobes.h>
57 #include <linux/pipe_fs_i.h>
58 #include <linux/oom.h>
59 #include <linux/kmod.h>
60 #include <linux/capability.h>
61 #include <linux/binfmts.h>
62 
63 #include <asm/uaccess.h>
64 #include <asm/processor.h>
65 
66 #ifdef CONFIG_X86
67 #include <asm/nmi.h>
68 #include <asm/stacktrace.h>
69 #include <asm/io.h>
70 #endif
71 #ifdef CONFIG_BSD_PROCESS_ACCT
72 #include <linux/acct.h>
73 #endif
74 #ifdef CONFIG_RT_MUTEXES
75 #include <linux/rtmutex.h>
76 #endif
77 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
78 #include <linux/lockdep.h>
79 #endif
80 #ifdef CONFIG_CHR_DEV_SG
81 #include <scsi/sg.h>
82 #endif
83 
84 #ifdef CONFIG_LOCKUP_DETECTOR
85 #include <linux/nmi.h>
86 #endif
87 
88 
89 #if defined(CONFIG_SYSCTL)
90 
91 /* External variables not in a header file. */
92 extern int sysctl_overcommit_memory;
93 extern int sysctl_overcommit_ratio;
94 extern int max_threads;
95 extern int core_uses_pid;
96 extern int suid_dumpable;
97 extern char core_pattern[];
98 extern unsigned int core_pipe_limit;
99 extern int pid_max;
100 extern int min_free_kbytes;
101 extern int pid_max_min, pid_max_max;
102 extern int sysctl_drop_caches;
103 extern int percpu_pagelist_fraction;
104 extern int compat_log;
105 extern int latencytop_enabled;
106 extern int sysctl_nr_open_min, sysctl_nr_open_max;
107 #ifndef CONFIG_MMU
108 extern int sysctl_nr_trim_pages;
109 #endif
110 #ifdef CONFIG_BLOCK
111 extern int blk_iopoll_enabled;
112 #endif
113 
114 /* Constants used for minimum and  maximum */
115 #ifdef CONFIG_LOCKUP_DETECTOR
116 static int sixty = 60;
117 static int neg_one = -1;
118 #endif
119 
120 static int zero;
121 static int __maybe_unused one = 1;
122 static int __maybe_unused two = 2;
123 static int __maybe_unused three = 3;
124 static unsigned long one_ul = 1;
125 static int one_hundred = 100;
126 #ifdef CONFIG_PRINTK
127 static int ten_thousand = 10000;
128 #endif
129 
130 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
131 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
132 
133 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
134 static int maxolduid = 65535;
135 static int minolduid;
136 static int min_percpu_pagelist_fract = 8;
137 
138 static int ngroups_max = NGROUPS_MAX;
139 static const int cap_last_cap = CAP_LAST_CAP;
140 
141 #ifdef CONFIG_INOTIFY_USER
142 #include <linux/inotify.h>
143 #endif
144 #ifdef CONFIG_SPARC
145 #include <asm/system.h>
146 #endif
147 
148 #ifdef CONFIG_SPARC64
149 extern int sysctl_tsb_ratio;
150 #endif
151 
152 #ifdef __hppa__
153 extern int pwrsw_enabled;
154 extern int unaligned_enabled;
155 #endif
156 
157 #ifdef CONFIG_IA64
158 extern int no_unaligned_warning;
159 extern int unaligned_dump_stack;
160 #endif
161 
162 #ifdef CONFIG_PROC_SYSCTL
163 static int proc_do_cad_pid(struct ctl_table *table, int write,
164 		  void __user *buffer, size_t *lenp, loff_t *ppos);
165 static int proc_taint(struct ctl_table *table, int write,
166 			       void __user *buffer, size_t *lenp, loff_t *ppos);
167 #endif
168 
169 #ifdef CONFIG_PRINTK
170 static int proc_dmesg_restrict(struct ctl_table *table, int write,
171 				void __user *buffer, size_t *lenp, loff_t *ppos);
172 #endif
173 
174 #ifdef CONFIG_MAGIC_SYSRQ
175 /* Note: sysrq code uses it's own private copy */
176 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
177 
178 static int sysrq_sysctl_handler(ctl_table *table, int write,
179 				void __user *buffer, size_t *lenp,
180 				loff_t *ppos)
181 {
182 	int error;
183 
184 	error = proc_dointvec(table, write, buffer, lenp, ppos);
185 	if (error)
186 		return error;
187 
188 	if (write)
189 		sysrq_toggle_support(__sysrq_enabled);
190 
191 	return 0;
192 }
193 
194 #endif
195 
196 static struct ctl_table root_table[];
197 static struct ctl_table_root sysctl_table_root;
198 static struct ctl_table_header root_table_header = {
199 	{{.count = 1,
200 	.ctl_table = root_table,
201 	.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
202 	.root = &sysctl_table_root,
203 	.set = &sysctl_table_root.default_set,
204 };
205 static struct ctl_table_root sysctl_table_root = {
206 	.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
207 	.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
208 };
209 
210 static struct ctl_table kern_table[];
211 static struct ctl_table vm_table[];
212 static struct ctl_table fs_table[];
213 static struct ctl_table debug_table[];
214 static struct ctl_table dev_table[];
215 extern struct ctl_table random_table[];
216 #ifdef CONFIG_EPOLL
217 extern struct ctl_table epoll_table[];
218 #endif
219 
220 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
221 int sysctl_legacy_va_layout;
222 #endif
223 
224 /* The default sysctl tables: */
225 
226 static struct ctl_table root_table[] = {
227 	{
228 		.procname	= "kernel",
229 		.mode		= 0555,
230 		.child		= kern_table,
231 	},
232 	{
233 		.procname	= "vm",
234 		.mode		= 0555,
235 		.child		= vm_table,
236 	},
237 	{
238 		.procname	= "fs",
239 		.mode		= 0555,
240 		.child		= fs_table,
241 	},
242 	{
243 		.procname	= "debug",
244 		.mode		= 0555,
245 		.child		= debug_table,
246 	},
247 	{
248 		.procname	= "dev",
249 		.mode		= 0555,
250 		.child		= dev_table,
251 	},
252 	{ }
253 };
254 
255 #ifdef CONFIG_SCHED_DEBUG
256 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
257 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
258 static int min_wakeup_granularity_ns;			/* 0 usecs */
259 static int max_wakeup_granularity_ns = NSEC_PER_SEC;	/* 1 second */
260 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
261 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
262 #endif
263 
264 #ifdef CONFIG_COMPACTION
265 static int min_extfrag_threshold;
266 static int max_extfrag_threshold = 1000;
267 #endif
268 
269 static struct ctl_table kern_table[] = {
270 	{
271 		.procname	= "sched_child_runs_first",
272 		.data		= &sysctl_sched_child_runs_first,
273 		.maxlen		= sizeof(unsigned int),
274 		.mode		= 0644,
275 		.proc_handler	= proc_dointvec,
276 	},
277 #ifdef CONFIG_SCHED_DEBUG
278 	{
279 		.procname	= "sched_min_granularity_ns",
280 		.data		= &sysctl_sched_min_granularity,
281 		.maxlen		= sizeof(unsigned int),
282 		.mode		= 0644,
283 		.proc_handler	= sched_proc_update_handler,
284 		.extra1		= &min_sched_granularity_ns,
285 		.extra2		= &max_sched_granularity_ns,
286 	},
287 	{
288 		.procname	= "sched_latency_ns",
289 		.data		= &sysctl_sched_latency,
290 		.maxlen		= sizeof(unsigned int),
291 		.mode		= 0644,
292 		.proc_handler	= sched_proc_update_handler,
293 		.extra1		= &min_sched_granularity_ns,
294 		.extra2		= &max_sched_granularity_ns,
295 	},
296 	{
297 		.procname	= "sched_wakeup_granularity_ns",
298 		.data		= &sysctl_sched_wakeup_granularity,
299 		.maxlen		= sizeof(unsigned int),
300 		.mode		= 0644,
301 		.proc_handler	= sched_proc_update_handler,
302 		.extra1		= &min_wakeup_granularity_ns,
303 		.extra2		= &max_wakeup_granularity_ns,
304 	},
305 	{
306 		.procname	= "sched_tunable_scaling",
307 		.data		= &sysctl_sched_tunable_scaling,
308 		.maxlen		= sizeof(enum sched_tunable_scaling),
309 		.mode		= 0644,
310 		.proc_handler	= sched_proc_update_handler,
311 		.extra1		= &min_sched_tunable_scaling,
312 		.extra2		= &max_sched_tunable_scaling,
313 	},
314 	{
315 		.procname	= "sched_migration_cost",
316 		.data		= &sysctl_sched_migration_cost,
317 		.maxlen		= sizeof(unsigned int),
318 		.mode		= 0644,
319 		.proc_handler	= proc_dointvec,
320 	},
321 	{
322 		.procname	= "sched_nr_migrate",
323 		.data		= &sysctl_sched_nr_migrate,
324 		.maxlen		= sizeof(unsigned int),
325 		.mode		= 0644,
326 		.proc_handler	= proc_dointvec,
327 	},
328 	{
329 		.procname	= "sched_time_avg",
330 		.data		= &sysctl_sched_time_avg,
331 		.maxlen		= sizeof(unsigned int),
332 		.mode		= 0644,
333 		.proc_handler	= proc_dointvec,
334 	},
335 	{
336 		.procname	= "sched_shares_window",
337 		.data		= &sysctl_sched_shares_window,
338 		.maxlen		= sizeof(unsigned int),
339 		.mode		= 0644,
340 		.proc_handler	= proc_dointvec,
341 	},
342 	{
343 		.procname	= "timer_migration",
344 		.data		= &sysctl_timer_migration,
345 		.maxlen		= sizeof(unsigned int),
346 		.mode		= 0644,
347 		.proc_handler	= proc_dointvec_minmax,
348 		.extra1		= &zero,
349 		.extra2		= &one,
350 	},
351 #endif
352 	{
353 		.procname	= "sched_rt_period_us",
354 		.data		= &sysctl_sched_rt_period,
355 		.maxlen		= sizeof(unsigned int),
356 		.mode		= 0644,
357 		.proc_handler	= sched_rt_handler,
358 	},
359 	{
360 		.procname	= "sched_rt_runtime_us",
361 		.data		= &sysctl_sched_rt_runtime,
362 		.maxlen		= sizeof(int),
363 		.mode		= 0644,
364 		.proc_handler	= sched_rt_handler,
365 	},
366 #ifdef CONFIG_SCHED_AUTOGROUP
367 	{
368 		.procname	= "sched_autogroup_enabled",
369 		.data		= &sysctl_sched_autogroup_enabled,
370 		.maxlen		= sizeof(unsigned int),
371 		.mode		= 0644,
372 		.proc_handler	= proc_dointvec_minmax,
373 		.extra1		= &zero,
374 		.extra2		= &one,
375 	},
376 #endif
377 #ifdef CONFIG_CFS_BANDWIDTH
378 	{
379 		.procname	= "sched_cfs_bandwidth_slice_us",
380 		.data		= &sysctl_sched_cfs_bandwidth_slice,
381 		.maxlen		= sizeof(unsigned int),
382 		.mode		= 0644,
383 		.proc_handler	= proc_dointvec_minmax,
384 		.extra1		= &one,
385 	},
386 #endif
387 #ifdef CONFIG_PROVE_LOCKING
388 	{
389 		.procname	= "prove_locking",
390 		.data		= &prove_locking,
391 		.maxlen		= sizeof(int),
392 		.mode		= 0644,
393 		.proc_handler	= proc_dointvec,
394 	},
395 #endif
396 #ifdef CONFIG_LOCK_STAT
397 	{
398 		.procname	= "lock_stat",
399 		.data		= &lock_stat,
400 		.maxlen		= sizeof(int),
401 		.mode		= 0644,
402 		.proc_handler	= proc_dointvec,
403 	},
404 #endif
405 	{
406 		.procname	= "panic",
407 		.data		= &panic_timeout,
408 		.maxlen		= sizeof(int),
409 		.mode		= 0644,
410 		.proc_handler	= proc_dointvec,
411 	},
412 	{
413 		.procname	= "core_uses_pid",
414 		.data		= &core_uses_pid,
415 		.maxlen		= sizeof(int),
416 		.mode		= 0644,
417 		.proc_handler	= proc_dointvec,
418 	},
419 	{
420 		.procname	= "core_pattern",
421 		.data		= core_pattern,
422 		.maxlen		= CORENAME_MAX_SIZE,
423 		.mode		= 0644,
424 		.proc_handler	= proc_dostring,
425 	},
426 	{
427 		.procname	= "core_pipe_limit",
428 		.data		= &core_pipe_limit,
429 		.maxlen		= sizeof(unsigned int),
430 		.mode		= 0644,
431 		.proc_handler	= proc_dointvec,
432 	},
433 #ifdef CONFIG_PROC_SYSCTL
434 	{
435 		.procname	= "tainted",
436 		.maxlen 	= sizeof(long),
437 		.mode		= 0644,
438 		.proc_handler	= proc_taint,
439 	},
440 #endif
441 #ifdef CONFIG_LATENCYTOP
442 	{
443 		.procname	= "latencytop",
444 		.data		= &latencytop_enabled,
445 		.maxlen		= sizeof(int),
446 		.mode		= 0644,
447 		.proc_handler	= proc_dointvec,
448 	},
449 #endif
450 #ifdef CONFIG_BLK_DEV_INITRD
451 	{
452 		.procname	= "real-root-dev",
453 		.data		= &real_root_dev,
454 		.maxlen		= sizeof(int),
455 		.mode		= 0644,
456 		.proc_handler	= proc_dointvec,
457 	},
458 #endif
459 	{
460 		.procname	= "print-fatal-signals",
461 		.data		= &print_fatal_signals,
462 		.maxlen		= sizeof(int),
463 		.mode		= 0644,
464 		.proc_handler	= proc_dointvec,
465 	},
466 #ifdef CONFIG_SPARC
467 	{
468 		.procname	= "reboot-cmd",
469 		.data		= reboot_command,
470 		.maxlen		= 256,
471 		.mode		= 0644,
472 		.proc_handler	= proc_dostring,
473 	},
474 	{
475 		.procname	= "stop-a",
476 		.data		= &stop_a_enabled,
477 		.maxlen		= sizeof (int),
478 		.mode		= 0644,
479 		.proc_handler	= proc_dointvec,
480 	},
481 	{
482 		.procname	= "scons-poweroff",
483 		.data		= &scons_pwroff,
484 		.maxlen		= sizeof (int),
485 		.mode		= 0644,
486 		.proc_handler	= proc_dointvec,
487 	},
488 #endif
489 #ifdef CONFIG_SPARC64
490 	{
491 		.procname	= "tsb-ratio",
492 		.data		= &sysctl_tsb_ratio,
493 		.maxlen		= sizeof (int),
494 		.mode		= 0644,
495 		.proc_handler	= proc_dointvec,
496 	},
497 #endif
498 #ifdef __hppa__
499 	{
500 		.procname	= "soft-power",
501 		.data		= &pwrsw_enabled,
502 		.maxlen		= sizeof (int),
503 	 	.mode		= 0644,
504 		.proc_handler	= proc_dointvec,
505 	},
506 	{
507 		.procname	= "unaligned-trap",
508 		.data		= &unaligned_enabled,
509 		.maxlen		= sizeof (int),
510 		.mode		= 0644,
511 		.proc_handler	= proc_dointvec,
512 	},
513 #endif
514 	{
515 		.procname	= "ctrl-alt-del",
516 		.data		= &C_A_D,
517 		.maxlen		= sizeof(int),
518 		.mode		= 0644,
519 		.proc_handler	= proc_dointvec,
520 	},
521 #ifdef CONFIG_FUNCTION_TRACER
522 	{
523 		.procname	= "ftrace_enabled",
524 		.data		= &ftrace_enabled,
525 		.maxlen		= sizeof(int),
526 		.mode		= 0644,
527 		.proc_handler	= ftrace_enable_sysctl,
528 	},
529 #endif
530 #ifdef CONFIG_STACK_TRACER
531 	{
532 		.procname	= "stack_tracer_enabled",
533 		.data		= &stack_tracer_enabled,
534 		.maxlen		= sizeof(int),
535 		.mode		= 0644,
536 		.proc_handler	= stack_trace_sysctl,
537 	},
538 #endif
539 #ifdef CONFIG_TRACING
540 	{
541 		.procname	= "ftrace_dump_on_oops",
542 		.data		= &ftrace_dump_on_oops,
543 		.maxlen		= sizeof(int),
544 		.mode		= 0644,
545 		.proc_handler	= proc_dointvec,
546 	},
547 #endif
548 #ifdef CONFIG_MODULES
549 	{
550 		.procname	= "modprobe",
551 		.data		= &modprobe_path,
552 		.maxlen		= KMOD_PATH_LEN,
553 		.mode		= 0644,
554 		.proc_handler	= proc_dostring,
555 	},
556 	{
557 		.procname	= "modules_disabled",
558 		.data		= &modules_disabled,
559 		.maxlen		= sizeof(int),
560 		.mode		= 0644,
561 		/* only handle a transition from default "0" to "1" */
562 		.proc_handler	= proc_dointvec_minmax,
563 		.extra1		= &one,
564 		.extra2		= &one,
565 	},
566 #endif
567 #ifdef CONFIG_HOTPLUG
568 	{
569 		.procname	= "hotplug",
570 		.data		= &uevent_helper,
571 		.maxlen		= UEVENT_HELPER_PATH_LEN,
572 		.mode		= 0644,
573 		.proc_handler	= proc_dostring,
574 	},
575 #endif
576 #ifdef CONFIG_CHR_DEV_SG
577 	{
578 		.procname	= "sg-big-buff",
579 		.data		= &sg_big_buff,
580 		.maxlen		= sizeof (int),
581 		.mode		= 0444,
582 		.proc_handler	= proc_dointvec,
583 	},
584 #endif
585 #ifdef CONFIG_BSD_PROCESS_ACCT
586 	{
587 		.procname	= "acct",
588 		.data		= &acct_parm,
589 		.maxlen		= 3*sizeof(int),
590 		.mode		= 0644,
591 		.proc_handler	= proc_dointvec,
592 	},
593 #endif
594 #ifdef CONFIG_MAGIC_SYSRQ
595 	{
596 		.procname	= "sysrq",
597 		.data		= &__sysrq_enabled,
598 		.maxlen		= sizeof (int),
599 		.mode		= 0644,
600 		.proc_handler	= sysrq_sysctl_handler,
601 	},
602 #endif
603 #ifdef CONFIG_PROC_SYSCTL
604 	{
605 		.procname	= "cad_pid",
606 		.data		= NULL,
607 		.maxlen		= sizeof (int),
608 		.mode		= 0600,
609 		.proc_handler	= proc_do_cad_pid,
610 	},
611 #endif
612 	{
613 		.procname	= "threads-max",
614 		.data		= &max_threads,
615 		.maxlen		= sizeof(int),
616 		.mode		= 0644,
617 		.proc_handler	= proc_dointvec,
618 	},
619 	{
620 		.procname	= "random",
621 		.mode		= 0555,
622 		.child		= random_table,
623 	},
624 	{
625 		.procname	= "usermodehelper",
626 		.mode		= 0555,
627 		.child		= usermodehelper_table,
628 	},
629 	{
630 		.procname	= "overflowuid",
631 		.data		= &overflowuid,
632 		.maxlen		= sizeof(int),
633 		.mode		= 0644,
634 		.proc_handler	= proc_dointvec_minmax,
635 		.extra1		= &minolduid,
636 		.extra2		= &maxolduid,
637 	},
638 	{
639 		.procname	= "overflowgid",
640 		.data		= &overflowgid,
641 		.maxlen		= sizeof(int),
642 		.mode		= 0644,
643 		.proc_handler	= proc_dointvec_minmax,
644 		.extra1		= &minolduid,
645 		.extra2		= &maxolduid,
646 	},
647 #ifdef CONFIG_S390
648 #ifdef CONFIG_MATHEMU
649 	{
650 		.procname	= "ieee_emulation_warnings",
651 		.data		= &sysctl_ieee_emulation_warnings,
652 		.maxlen		= sizeof(int),
653 		.mode		= 0644,
654 		.proc_handler	= proc_dointvec,
655 	},
656 #endif
657 	{
658 		.procname	= "userprocess_debug",
659 		.data		= &show_unhandled_signals,
660 		.maxlen		= sizeof(int),
661 		.mode		= 0644,
662 		.proc_handler	= proc_dointvec,
663 	},
664 #endif
665 	{
666 		.procname	= "pid_max",
667 		.data		= &pid_max,
668 		.maxlen		= sizeof (int),
669 		.mode		= 0644,
670 		.proc_handler	= proc_dointvec_minmax,
671 		.extra1		= &pid_max_min,
672 		.extra2		= &pid_max_max,
673 	},
674 	{
675 		.procname	= "panic_on_oops",
676 		.data		= &panic_on_oops,
677 		.maxlen		= sizeof(int),
678 		.mode		= 0644,
679 		.proc_handler	= proc_dointvec,
680 	},
681 #if defined CONFIG_PRINTK
682 	{
683 		.procname	= "printk",
684 		.data		= &console_loglevel,
685 		.maxlen		= 4*sizeof(int),
686 		.mode		= 0644,
687 		.proc_handler	= proc_dointvec,
688 	},
689 	{
690 		.procname	= "printk_ratelimit",
691 		.data		= &printk_ratelimit_state.interval,
692 		.maxlen		= sizeof(int),
693 		.mode		= 0644,
694 		.proc_handler	= proc_dointvec_jiffies,
695 	},
696 	{
697 		.procname	= "printk_ratelimit_burst",
698 		.data		= &printk_ratelimit_state.burst,
699 		.maxlen		= sizeof(int),
700 		.mode		= 0644,
701 		.proc_handler	= proc_dointvec,
702 	},
703 	{
704 		.procname	= "printk_delay",
705 		.data		= &printk_delay_msec,
706 		.maxlen		= sizeof(int),
707 		.mode		= 0644,
708 		.proc_handler	= proc_dointvec_minmax,
709 		.extra1		= &zero,
710 		.extra2		= &ten_thousand,
711 	},
712 	{
713 		.procname	= "dmesg_restrict",
714 		.data		= &dmesg_restrict,
715 		.maxlen		= sizeof(int),
716 		.mode		= 0644,
717 		.proc_handler	= proc_dointvec_minmax,
718 		.extra1		= &zero,
719 		.extra2		= &one,
720 	},
721 	{
722 		.procname	= "kptr_restrict",
723 		.data		= &kptr_restrict,
724 		.maxlen		= sizeof(int),
725 		.mode		= 0644,
726 		.proc_handler	= proc_dmesg_restrict,
727 		.extra1		= &zero,
728 		.extra2		= &two,
729 	},
730 #endif
731 	{
732 		.procname	= "ngroups_max",
733 		.data		= &ngroups_max,
734 		.maxlen		= sizeof (int),
735 		.mode		= 0444,
736 		.proc_handler	= proc_dointvec,
737 	},
738 	{
739 		.procname	= "cap_last_cap",
740 		.data		= (void *)&cap_last_cap,
741 		.maxlen		= sizeof(int),
742 		.mode		= 0444,
743 		.proc_handler	= proc_dointvec,
744 	},
745 #if defined(CONFIG_LOCKUP_DETECTOR)
746 	{
747 		.procname       = "watchdog",
748 		.data           = &watchdog_enabled,
749 		.maxlen         = sizeof (int),
750 		.mode           = 0644,
751 		.proc_handler   = proc_dowatchdog,
752 		.extra1		= &zero,
753 		.extra2		= &one,
754 	},
755 	{
756 		.procname	= "watchdog_thresh",
757 		.data		= &watchdog_thresh,
758 		.maxlen		= sizeof(int),
759 		.mode		= 0644,
760 		.proc_handler	= proc_dowatchdog,
761 		.extra1		= &neg_one,
762 		.extra2		= &sixty,
763 	},
764 	{
765 		.procname	= "softlockup_panic",
766 		.data		= &softlockup_panic,
767 		.maxlen		= sizeof(int),
768 		.mode		= 0644,
769 		.proc_handler	= proc_dointvec_minmax,
770 		.extra1		= &zero,
771 		.extra2		= &one,
772 	},
773 	{
774 		.procname       = "nmi_watchdog",
775 		.data           = &watchdog_enabled,
776 		.maxlen         = sizeof (int),
777 		.mode           = 0644,
778 		.proc_handler   = proc_dowatchdog,
779 		.extra1		= &zero,
780 		.extra2		= &one,
781 	},
782 #endif
783 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
784 	{
785 		.procname       = "unknown_nmi_panic",
786 		.data           = &unknown_nmi_panic,
787 		.maxlen         = sizeof (int),
788 		.mode           = 0644,
789 		.proc_handler   = proc_dointvec,
790 	},
791 #endif
792 #if defined(CONFIG_X86)
793 	{
794 		.procname	= "panic_on_unrecovered_nmi",
795 		.data		= &panic_on_unrecovered_nmi,
796 		.maxlen		= sizeof(int),
797 		.mode		= 0644,
798 		.proc_handler	= proc_dointvec,
799 	},
800 	{
801 		.procname	= "panic_on_io_nmi",
802 		.data		= &panic_on_io_nmi,
803 		.maxlen		= sizeof(int),
804 		.mode		= 0644,
805 		.proc_handler	= proc_dointvec,
806 	},
807 #ifdef CONFIG_DEBUG_STACKOVERFLOW
808 	{
809 		.procname	= "panic_on_stackoverflow",
810 		.data		= &sysctl_panic_on_stackoverflow,
811 		.maxlen		= sizeof(int),
812 		.mode		= 0644,
813 		.proc_handler	= proc_dointvec,
814 	},
815 #endif
816 	{
817 		.procname	= "bootloader_type",
818 		.data		= &bootloader_type,
819 		.maxlen		= sizeof (int),
820 		.mode		= 0444,
821 		.proc_handler	= proc_dointvec,
822 	},
823 	{
824 		.procname	= "bootloader_version",
825 		.data		= &bootloader_version,
826 		.maxlen		= sizeof (int),
827 		.mode		= 0444,
828 		.proc_handler	= proc_dointvec,
829 	},
830 	{
831 		.procname	= "kstack_depth_to_print",
832 		.data		= &kstack_depth_to_print,
833 		.maxlen		= sizeof(int),
834 		.mode		= 0644,
835 		.proc_handler	= proc_dointvec,
836 	},
837 	{
838 		.procname	= "io_delay_type",
839 		.data		= &io_delay_type,
840 		.maxlen		= sizeof(int),
841 		.mode		= 0644,
842 		.proc_handler	= proc_dointvec,
843 	},
844 #endif
845 #if defined(CONFIG_MMU)
846 	{
847 		.procname	= "randomize_va_space",
848 		.data		= &randomize_va_space,
849 		.maxlen		= sizeof(int),
850 		.mode		= 0644,
851 		.proc_handler	= proc_dointvec,
852 	},
853 #endif
854 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
855 	{
856 		.procname	= "spin_retry",
857 		.data		= &spin_retry,
858 		.maxlen		= sizeof (int),
859 		.mode		= 0644,
860 		.proc_handler	= proc_dointvec,
861 	},
862 #endif
863 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
864 	{
865 		.procname	= "acpi_video_flags",
866 		.data		= &acpi_realmode_flags,
867 		.maxlen		= sizeof (unsigned long),
868 		.mode		= 0644,
869 		.proc_handler	= proc_doulongvec_minmax,
870 	},
871 #endif
872 #ifdef CONFIG_IA64
873 	{
874 		.procname	= "ignore-unaligned-usertrap",
875 		.data		= &no_unaligned_warning,
876 		.maxlen		= sizeof (int),
877 	 	.mode		= 0644,
878 		.proc_handler	= proc_dointvec,
879 	},
880 	{
881 		.procname	= "unaligned-dump-stack",
882 		.data		= &unaligned_dump_stack,
883 		.maxlen		= sizeof (int),
884 		.mode		= 0644,
885 		.proc_handler	= proc_dointvec,
886 	},
887 #endif
888 #ifdef CONFIG_DETECT_HUNG_TASK
889 	{
890 		.procname	= "hung_task_panic",
891 		.data		= &sysctl_hung_task_panic,
892 		.maxlen		= sizeof(int),
893 		.mode		= 0644,
894 		.proc_handler	= proc_dointvec_minmax,
895 		.extra1		= &zero,
896 		.extra2		= &one,
897 	},
898 	{
899 		.procname	= "hung_task_check_count",
900 		.data		= &sysctl_hung_task_check_count,
901 		.maxlen		= sizeof(unsigned long),
902 		.mode		= 0644,
903 		.proc_handler	= proc_doulongvec_minmax,
904 	},
905 	{
906 		.procname	= "hung_task_timeout_secs",
907 		.data		= &sysctl_hung_task_timeout_secs,
908 		.maxlen		= sizeof(unsigned long),
909 		.mode		= 0644,
910 		.proc_handler	= proc_dohung_task_timeout_secs,
911 	},
912 	{
913 		.procname	= "hung_task_warnings",
914 		.data		= &sysctl_hung_task_warnings,
915 		.maxlen		= sizeof(unsigned long),
916 		.mode		= 0644,
917 		.proc_handler	= proc_doulongvec_minmax,
918 	},
919 #endif
920 #ifdef CONFIG_COMPAT
921 	{
922 		.procname	= "compat-log",
923 		.data		= &compat_log,
924 		.maxlen		= sizeof (int),
925 	 	.mode		= 0644,
926 		.proc_handler	= proc_dointvec,
927 	},
928 #endif
929 #ifdef CONFIG_RT_MUTEXES
930 	{
931 		.procname	= "max_lock_depth",
932 		.data		= &max_lock_depth,
933 		.maxlen		= sizeof(int),
934 		.mode		= 0644,
935 		.proc_handler	= proc_dointvec,
936 	},
937 #endif
938 	{
939 		.procname	= "poweroff_cmd",
940 		.data		= &poweroff_cmd,
941 		.maxlen		= POWEROFF_CMD_PATH_LEN,
942 		.mode		= 0644,
943 		.proc_handler	= proc_dostring,
944 	},
945 #ifdef CONFIG_KEYS
946 	{
947 		.procname	= "keys",
948 		.mode		= 0555,
949 		.child		= key_sysctls,
950 	},
951 #endif
952 #ifdef CONFIG_RCU_TORTURE_TEST
953 	{
954 		.procname       = "rcutorture_runnable",
955 		.data           = &rcutorture_runnable,
956 		.maxlen         = sizeof(int),
957 		.mode           = 0644,
958 		.proc_handler	= proc_dointvec,
959 	},
960 #endif
961 #ifdef CONFIG_PERF_EVENTS
962 	/*
963 	 * User-space scripts rely on the existence of this file
964 	 * as a feature check for perf_events being enabled.
965 	 *
966 	 * So it's an ABI, do not remove!
967 	 */
968 	{
969 		.procname	= "perf_event_paranoid",
970 		.data		= &sysctl_perf_event_paranoid,
971 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
972 		.mode		= 0644,
973 		.proc_handler	= proc_dointvec,
974 	},
975 	{
976 		.procname	= "perf_event_mlock_kb",
977 		.data		= &sysctl_perf_event_mlock,
978 		.maxlen		= sizeof(sysctl_perf_event_mlock),
979 		.mode		= 0644,
980 		.proc_handler	= proc_dointvec,
981 	},
982 	{
983 		.procname	= "perf_event_max_sample_rate",
984 		.data		= &sysctl_perf_event_sample_rate,
985 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
986 		.mode		= 0644,
987 		.proc_handler	= perf_proc_update_handler,
988 	},
989 #endif
990 #ifdef CONFIG_KMEMCHECK
991 	{
992 		.procname	= "kmemcheck",
993 		.data		= &kmemcheck_enabled,
994 		.maxlen		= sizeof(int),
995 		.mode		= 0644,
996 		.proc_handler	= proc_dointvec,
997 	},
998 #endif
999 #ifdef CONFIG_BLOCK
1000 	{
1001 		.procname	= "blk_iopoll",
1002 		.data		= &blk_iopoll_enabled,
1003 		.maxlen		= sizeof(int),
1004 		.mode		= 0644,
1005 		.proc_handler	= proc_dointvec,
1006 	},
1007 #endif
1008 	{ }
1009 };
1010 
1011 static struct ctl_table vm_table[] = {
1012 	{
1013 		.procname	= "overcommit_memory",
1014 		.data		= &sysctl_overcommit_memory,
1015 		.maxlen		= sizeof(sysctl_overcommit_memory),
1016 		.mode		= 0644,
1017 		.proc_handler	= proc_dointvec_minmax,
1018 		.extra1		= &zero,
1019 		.extra2		= &two,
1020 	},
1021 	{
1022 		.procname	= "panic_on_oom",
1023 		.data		= &sysctl_panic_on_oom,
1024 		.maxlen		= sizeof(sysctl_panic_on_oom),
1025 		.mode		= 0644,
1026 		.proc_handler	= proc_dointvec_minmax,
1027 		.extra1		= &zero,
1028 		.extra2		= &two,
1029 	},
1030 	{
1031 		.procname	= "oom_kill_allocating_task",
1032 		.data		= &sysctl_oom_kill_allocating_task,
1033 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1034 		.mode		= 0644,
1035 		.proc_handler	= proc_dointvec,
1036 	},
1037 	{
1038 		.procname	= "oom_dump_tasks",
1039 		.data		= &sysctl_oom_dump_tasks,
1040 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1041 		.mode		= 0644,
1042 		.proc_handler	= proc_dointvec,
1043 	},
1044 	{
1045 		.procname	= "overcommit_ratio",
1046 		.data		= &sysctl_overcommit_ratio,
1047 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1048 		.mode		= 0644,
1049 		.proc_handler	= proc_dointvec,
1050 	},
1051 	{
1052 		.procname	= "page-cluster",
1053 		.data		= &page_cluster,
1054 		.maxlen		= sizeof(int),
1055 		.mode		= 0644,
1056 		.proc_handler	= proc_dointvec_minmax,
1057 		.extra1		= &zero,
1058 	},
1059 	{
1060 		.procname	= "dirty_background_ratio",
1061 		.data		= &dirty_background_ratio,
1062 		.maxlen		= sizeof(dirty_background_ratio),
1063 		.mode		= 0644,
1064 		.proc_handler	= dirty_background_ratio_handler,
1065 		.extra1		= &zero,
1066 		.extra2		= &one_hundred,
1067 	},
1068 	{
1069 		.procname	= "dirty_background_bytes",
1070 		.data		= &dirty_background_bytes,
1071 		.maxlen		= sizeof(dirty_background_bytes),
1072 		.mode		= 0644,
1073 		.proc_handler	= dirty_background_bytes_handler,
1074 		.extra1		= &one_ul,
1075 	},
1076 	{
1077 		.procname	= "dirty_ratio",
1078 		.data		= &vm_dirty_ratio,
1079 		.maxlen		= sizeof(vm_dirty_ratio),
1080 		.mode		= 0644,
1081 		.proc_handler	= dirty_ratio_handler,
1082 		.extra1		= &zero,
1083 		.extra2		= &one_hundred,
1084 	},
1085 	{
1086 		.procname	= "dirty_bytes",
1087 		.data		= &vm_dirty_bytes,
1088 		.maxlen		= sizeof(vm_dirty_bytes),
1089 		.mode		= 0644,
1090 		.proc_handler	= dirty_bytes_handler,
1091 		.extra1		= &dirty_bytes_min,
1092 	},
1093 	{
1094 		.procname	= "dirty_writeback_centisecs",
1095 		.data		= &dirty_writeback_interval,
1096 		.maxlen		= sizeof(dirty_writeback_interval),
1097 		.mode		= 0644,
1098 		.proc_handler	= dirty_writeback_centisecs_handler,
1099 	},
1100 	{
1101 		.procname	= "dirty_expire_centisecs",
1102 		.data		= &dirty_expire_interval,
1103 		.maxlen		= sizeof(dirty_expire_interval),
1104 		.mode		= 0644,
1105 		.proc_handler	= proc_dointvec_minmax,
1106 		.extra1		= &zero,
1107 	},
1108 	{
1109 		.procname	= "nr_pdflush_threads",
1110 		.data		= &nr_pdflush_threads,
1111 		.maxlen		= sizeof nr_pdflush_threads,
1112 		.mode		= 0444 /* read-only*/,
1113 		.proc_handler	= proc_dointvec,
1114 	},
1115 	{
1116 		.procname	= "swappiness",
1117 		.data		= &vm_swappiness,
1118 		.maxlen		= sizeof(vm_swappiness),
1119 		.mode		= 0644,
1120 		.proc_handler	= proc_dointvec_minmax,
1121 		.extra1		= &zero,
1122 		.extra2		= &one_hundred,
1123 	},
1124 #ifdef CONFIG_HUGETLB_PAGE
1125 	{
1126 		.procname	= "nr_hugepages",
1127 		.data		= NULL,
1128 		.maxlen		= sizeof(unsigned long),
1129 		.mode		= 0644,
1130 		.proc_handler	= hugetlb_sysctl_handler,
1131 		.extra1		= (void *)&hugetlb_zero,
1132 		.extra2		= (void *)&hugetlb_infinity,
1133 	},
1134 #ifdef CONFIG_NUMA
1135 	{
1136 		.procname       = "nr_hugepages_mempolicy",
1137 		.data           = NULL,
1138 		.maxlen         = sizeof(unsigned long),
1139 		.mode           = 0644,
1140 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1141 		.extra1		= (void *)&hugetlb_zero,
1142 		.extra2		= (void *)&hugetlb_infinity,
1143 	},
1144 #endif
1145 	 {
1146 		.procname	= "hugetlb_shm_group",
1147 		.data		= &sysctl_hugetlb_shm_group,
1148 		.maxlen		= sizeof(gid_t),
1149 		.mode		= 0644,
1150 		.proc_handler	= proc_dointvec,
1151 	 },
1152 	 {
1153 		.procname	= "hugepages_treat_as_movable",
1154 		.data		= &hugepages_treat_as_movable,
1155 		.maxlen		= sizeof(int),
1156 		.mode		= 0644,
1157 		.proc_handler	= hugetlb_treat_movable_handler,
1158 	},
1159 	{
1160 		.procname	= "nr_overcommit_hugepages",
1161 		.data		= NULL,
1162 		.maxlen		= sizeof(unsigned long),
1163 		.mode		= 0644,
1164 		.proc_handler	= hugetlb_overcommit_handler,
1165 		.extra1		= (void *)&hugetlb_zero,
1166 		.extra2		= (void *)&hugetlb_infinity,
1167 	},
1168 #endif
1169 	{
1170 		.procname	= "lowmem_reserve_ratio",
1171 		.data		= &sysctl_lowmem_reserve_ratio,
1172 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1173 		.mode		= 0644,
1174 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1175 	},
1176 	{
1177 		.procname	= "drop_caches",
1178 		.data		= &sysctl_drop_caches,
1179 		.maxlen		= sizeof(int),
1180 		.mode		= 0644,
1181 		.proc_handler	= drop_caches_sysctl_handler,
1182 		.extra1		= &one,
1183 		.extra2		= &three,
1184 	},
1185 #ifdef CONFIG_COMPACTION
1186 	{
1187 		.procname	= "compact_memory",
1188 		.data		= &sysctl_compact_memory,
1189 		.maxlen		= sizeof(int),
1190 		.mode		= 0200,
1191 		.proc_handler	= sysctl_compaction_handler,
1192 	},
1193 	{
1194 		.procname	= "extfrag_threshold",
1195 		.data		= &sysctl_extfrag_threshold,
1196 		.maxlen		= sizeof(int),
1197 		.mode		= 0644,
1198 		.proc_handler	= sysctl_extfrag_handler,
1199 		.extra1		= &min_extfrag_threshold,
1200 		.extra2		= &max_extfrag_threshold,
1201 	},
1202 
1203 #endif /* CONFIG_COMPACTION */
1204 	{
1205 		.procname	= "min_free_kbytes",
1206 		.data		= &min_free_kbytes,
1207 		.maxlen		= sizeof(min_free_kbytes),
1208 		.mode		= 0644,
1209 		.proc_handler	= min_free_kbytes_sysctl_handler,
1210 		.extra1		= &zero,
1211 	},
1212 	{
1213 		.procname	= "percpu_pagelist_fraction",
1214 		.data		= &percpu_pagelist_fraction,
1215 		.maxlen		= sizeof(percpu_pagelist_fraction),
1216 		.mode		= 0644,
1217 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1218 		.extra1		= &min_percpu_pagelist_fract,
1219 	},
1220 #ifdef CONFIG_MMU
1221 	{
1222 		.procname	= "max_map_count",
1223 		.data		= &sysctl_max_map_count,
1224 		.maxlen		= sizeof(sysctl_max_map_count),
1225 		.mode		= 0644,
1226 		.proc_handler	= proc_dointvec_minmax,
1227 		.extra1		= &zero,
1228 	},
1229 #else
1230 	{
1231 		.procname	= "nr_trim_pages",
1232 		.data		= &sysctl_nr_trim_pages,
1233 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1234 		.mode		= 0644,
1235 		.proc_handler	= proc_dointvec_minmax,
1236 		.extra1		= &zero,
1237 	},
1238 #endif
1239 	{
1240 		.procname	= "laptop_mode",
1241 		.data		= &laptop_mode,
1242 		.maxlen		= sizeof(laptop_mode),
1243 		.mode		= 0644,
1244 		.proc_handler	= proc_dointvec_jiffies,
1245 	},
1246 	{
1247 		.procname	= "block_dump",
1248 		.data		= &block_dump,
1249 		.maxlen		= sizeof(block_dump),
1250 		.mode		= 0644,
1251 		.proc_handler	= proc_dointvec,
1252 		.extra1		= &zero,
1253 	},
1254 	{
1255 		.procname	= "vfs_cache_pressure",
1256 		.data		= &sysctl_vfs_cache_pressure,
1257 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1258 		.mode		= 0644,
1259 		.proc_handler	= proc_dointvec,
1260 		.extra1		= &zero,
1261 	},
1262 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1263 	{
1264 		.procname	= "legacy_va_layout",
1265 		.data		= &sysctl_legacy_va_layout,
1266 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1267 		.mode		= 0644,
1268 		.proc_handler	= proc_dointvec,
1269 		.extra1		= &zero,
1270 	},
1271 #endif
1272 #ifdef CONFIG_NUMA
1273 	{
1274 		.procname	= "zone_reclaim_mode",
1275 		.data		= &zone_reclaim_mode,
1276 		.maxlen		= sizeof(zone_reclaim_mode),
1277 		.mode		= 0644,
1278 		.proc_handler	= proc_dointvec,
1279 		.extra1		= &zero,
1280 	},
1281 	{
1282 		.procname	= "min_unmapped_ratio",
1283 		.data		= &sysctl_min_unmapped_ratio,
1284 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1285 		.mode		= 0644,
1286 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1287 		.extra1		= &zero,
1288 		.extra2		= &one_hundred,
1289 	},
1290 	{
1291 		.procname	= "min_slab_ratio",
1292 		.data		= &sysctl_min_slab_ratio,
1293 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1294 		.mode		= 0644,
1295 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1296 		.extra1		= &zero,
1297 		.extra2		= &one_hundred,
1298 	},
1299 #endif
1300 #ifdef CONFIG_SMP
1301 	{
1302 		.procname	= "stat_interval",
1303 		.data		= &sysctl_stat_interval,
1304 		.maxlen		= sizeof(sysctl_stat_interval),
1305 		.mode		= 0644,
1306 		.proc_handler	= proc_dointvec_jiffies,
1307 	},
1308 #endif
1309 #ifdef CONFIG_MMU
1310 	{
1311 		.procname	= "mmap_min_addr",
1312 		.data		= &dac_mmap_min_addr,
1313 		.maxlen		= sizeof(unsigned long),
1314 		.mode		= 0644,
1315 		.proc_handler	= mmap_min_addr_handler,
1316 	},
1317 #endif
1318 #ifdef CONFIG_NUMA
1319 	{
1320 		.procname	= "numa_zonelist_order",
1321 		.data		= &numa_zonelist_order,
1322 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1323 		.mode		= 0644,
1324 		.proc_handler	= numa_zonelist_order_handler,
1325 	},
1326 #endif
1327 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1328    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1329 	{
1330 		.procname	= "vdso_enabled",
1331 		.data		= &vdso_enabled,
1332 		.maxlen		= sizeof(vdso_enabled),
1333 		.mode		= 0644,
1334 		.proc_handler	= proc_dointvec,
1335 		.extra1		= &zero,
1336 	},
1337 #endif
1338 #ifdef CONFIG_HIGHMEM
1339 	{
1340 		.procname	= "highmem_is_dirtyable",
1341 		.data		= &vm_highmem_is_dirtyable,
1342 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1343 		.mode		= 0644,
1344 		.proc_handler	= proc_dointvec_minmax,
1345 		.extra1		= &zero,
1346 		.extra2		= &one,
1347 	},
1348 #endif
1349 	{
1350 		.procname	= "scan_unevictable_pages",
1351 		.data		= &scan_unevictable_pages,
1352 		.maxlen		= sizeof(scan_unevictable_pages),
1353 		.mode		= 0644,
1354 		.proc_handler	= scan_unevictable_handler,
1355 	},
1356 #ifdef CONFIG_MEMORY_FAILURE
1357 	{
1358 		.procname	= "memory_failure_early_kill",
1359 		.data		= &sysctl_memory_failure_early_kill,
1360 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1361 		.mode		= 0644,
1362 		.proc_handler	= proc_dointvec_minmax,
1363 		.extra1		= &zero,
1364 		.extra2		= &one,
1365 	},
1366 	{
1367 		.procname	= "memory_failure_recovery",
1368 		.data		= &sysctl_memory_failure_recovery,
1369 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1370 		.mode		= 0644,
1371 		.proc_handler	= proc_dointvec_minmax,
1372 		.extra1		= &zero,
1373 		.extra2		= &one,
1374 	},
1375 #endif
1376 	{ }
1377 };
1378 
1379 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1380 static struct ctl_table binfmt_misc_table[] = {
1381 	{ }
1382 };
1383 #endif
1384 
1385 static struct ctl_table fs_table[] = {
1386 	{
1387 		.procname	= "inode-nr",
1388 		.data		= &inodes_stat,
1389 		.maxlen		= 2*sizeof(int),
1390 		.mode		= 0444,
1391 		.proc_handler	= proc_nr_inodes,
1392 	},
1393 	{
1394 		.procname	= "inode-state",
1395 		.data		= &inodes_stat,
1396 		.maxlen		= 7*sizeof(int),
1397 		.mode		= 0444,
1398 		.proc_handler	= proc_nr_inodes,
1399 	},
1400 	{
1401 		.procname	= "file-nr",
1402 		.data		= &files_stat,
1403 		.maxlen		= sizeof(files_stat),
1404 		.mode		= 0444,
1405 		.proc_handler	= proc_nr_files,
1406 	},
1407 	{
1408 		.procname	= "file-max",
1409 		.data		= &files_stat.max_files,
1410 		.maxlen		= sizeof(files_stat.max_files),
1411 		.mode		= 0644,
1412 		.proc_handler	= proc_doulongvec_minmax,
1413 	},
1414 	{
1415 		.procname	= "nr_open",
1416 		.data		= &sysctl_nr_open,
1417 		.maxlen		= sizeof(int),
1418 		.mode		= 0644,
1419 		.proc_handler	= proc_dointvec_minmax,
1420 		.extra1		= &sysctl_nr_open_min,
1421 		.extra2		= &sysctl_nr_open_max,
1422 	},
1423 	{
1424 		.procname	= "dentry-state",
1425 		.data		= &dentry_stat,
1426 		.maxlen		= 6*sizeof(int),
1427 		.mode		= 0444,
1428 		.proc_handler	= proc_nr_dentry,
1429 	},
1430 	{
1431 		.procname	= "overflowuid",
1432 		.data		= &fs_overflowuid,
1433 		.maxlen		= sizeof(int),
1434 		.mode		= 0644,
1435 		.proc_handler	= proc_dointvec_minmax,
1436 		.extra1		= &minolduid,
1437 		.extra2		= &maxolduid,
1438 	},
1439 	{
1440 		.procname	= "overflowgid",
1441 		.data		= &fs_overflowgid,
1442 		.maxlen		= sizeof(int),
1443 		.mode		= 0644,
1444 		.proc_handler	= proc_dointvec_minmax,
1445 		.extra1		= &minolduid,
1446 		.extra2		= &maxolduid,
1447 	},
1448 #ifdef CONFIG_FILE_LOCKING
1449 	{
1450 		.procname	= "leases-enable",
1451 		.data		= &leases_enable,
1452 		.maxlen		= sizeof(int),
1453 		.mode		= 0644,
1454 		.proc_handler	= proc_dointvec,
1455 	},
1456 #endif
1457 #ifdef CONFIG_DNOTIFY
1458 	{
1459 		.procname	= "dir-notify-enable",
1460 		.data		= &dir_notify_enable,
1461 		.maxlen		= sizeof(int),
1462 		.mode		= 0644,
1463 		.proc_handler	= proc_dointvec,
1464 	},
1465 #endif
1466 #ifdef CONFIG_MMU
1467 #ifdef CONFIG_FILE_LOCKING
1468 	{
1469 		.procname	= "lease-break-time",
1470 		.data		= &lease_break_time,
1471 		.maxlen		= sizeof(int),
1472 		.mode		= 0644,
1473 		.proc_handler	= proc_dointvec,
1474 	},
1475 #endif
1476 #ifdef CONFIG_AIO
1477 	{
1478 		.procname	= "aio-nr",
1479 		.data		= &aio_nr,
1480 		.maxlen		= sizeof(aio_nr),
1481 		.mode		= 0444,
1482 		.proc_handler	= proc_doulongvec_minmax,
1483 	},
1484 	{
1485 		.procname	= "aio-max-nr",
1486 		.data		= &aio_max_nr,
1487 		.maxlen		= sizeof(aio_max_nr),
1488 		.mode		= 0644,
1489 		.proc_handler	= proc_doulongvec_minmax,
1490 	},
1491 #endif /* CONFIG_AIO */
1492 #ifdef CONFIG_INOTIFY_USER
1493 	{
1494 		.procname	= "inotify",
1495 		.mode		= 0555,
1496 		.child		= inotify_table,
1497 	},
1498 #endif
1499 #ifdef CONFIG_EPOLL
1500 	{
1501 		.procname	= "epoll",
1502 		.mode		= 0555,
1503 		.child		= epoll_table,
1504 	},
1505 #endif
1506 #endif
1507 	{
1508 		.procname	= "suid_dumpable",
1509 		.data		= &suid_dumpable,
1510 		.maxlen		= sizeof(int),
1511 		.mode		= 0644,
1512 		.proc_handler	= proc_dointvec_minmax,
1513 		.extra1		= &zero,
1514 		.extra2		= &two,
1515 	},
1516 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1517 	{
1518 		.procname	= "binfmt_misc",
1519 		.mode		= 0555,
1520 		.child		= binfmt_misc_table,
1521 	},
1522 #endif
1523 	{
1524 		.procname	= "pipe-max-size",
1525 		.data		= &pipe_max_size,
1526 		.maxlen		= sizeof(int),
1527 		.mode		= 0644,
1528 		.proc_handler	= &pipe_proc_fn,
1529 		.extra1		= &pipe_min_size,
1530 	},
1531 	{ }
1532 };
1533 
1534 static struct ctl_table debug_table[] = {
1535 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1536     defined(CONFIG_S390) || defined(CONFIG_TILE)
1537 	{
1538 		.procname	= "exception-trace",
1539 		.data		= &show_unhandled_signals,
1540 		.maxlen		= sizeof(int),
1541 		.mode		= 0644,
1542 		.proc_handler	= proc_dointvec
1543 	},
1544 #endif
1545 #if defined(CONFIG_OPTPROBES)
1546 	{
1547 		.procname	= "kprobes-optimization",
1548 		.data		= &sysctl_kprobes_optimization,
1549 		.maxlen		= sizeof(int),
1550 		.mode		= 0644,
1551 		.proc_handler	= proc_kprobes_optimization_handler,
1552 		.extra1		= &zero,
1553 		.extra2		= &one,
1554 	},
1555 #endif
1556 	{ }
1557 };
1558 
1559 static struct ctl_table dev_table[] = {
1560 	{ }
1561 };
1562 
1563 static DEFINE_SPINLOCK(sysctl_lock);
1564 
1565 /* called under sysctl_lock */
1566 static int use_table(struct ctl_table_header *p)
1567 {
1568 	if (unlikely(p->unregistering))
1569 		return 0;
1570 	p->used++;
1571 	return 1;
1572 }
1573 
1574 /* called under sysctl_lock */
1575 static void unuse_table(struct ctl_table_header *p)
1576 {
1577 	if (!--p->used)
1578 		if (unlikely(p->unregistering))
1579 			complete(p->unregistering);
1580 }
1581 
1582 /* called under sysctl_lock, will reacquire if has to wait */
1583 static void start_unregistering(struct ctl_table_header *p)
1584 {
1585 	/*
1586 	 * if p->used is 0, nobody will ever touch that entry again;
1587 	 * we'll eliminate all paths to it before dropping sysctl_lock
1588 	 */
1589 	if (unlikely(p->used)) {
1590 		struct completion wait;
1591 		init_completion(&wait);
1592 		p->unregistering = &wait;
1593 		spin_unlock(&sysctl_lock);
1594 		wait_for_completion(&wait);
1595 		spin_lock(&sysctl_lock);
1596 	} else {
1597 		/* anything non-NULL; we'll never dereference it */
1598 		p->unregistering = ERR_PTR(-EINVAL);
1599 	}
1600 	/*
1601 	 * do not remove from the list until nobody holds it; walking the
1602 	 * list in do_sysctl() relies on that.
1603 	 */
1604 	list_del_init(&p->ctl_entry);
1605 }
1606 
1607 void sysctl_head_get(struct ctl_table_header *head)
1608 {
1609 	spin_lock(&sysctl_lock);
1610 	head->count++;
1611 	spin_unlock(&sysctl_lock);
1612 }
1613 
1614 void sysctl_head_put(struct ctl_table_header *head)
1615 {
1616 	spin_lock(&sysctl_lock);
1617 	if (!--head->count)
1618 		kfree_rcu(head, rcu);
1619 	spin_unlock(&sysctl_lock);
1620 }
1621 
1622 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1623 {
1624 	if (!head)
1625 		BUG();
1626 	spin_lock(&sysctl_lock);
1627 	if (!use_table(head))
1628 		head = ERR_PTR(-ENOENT);
1629 	spin_unlock(&sysctl_lock);
1630 	return head;
1631 }
1632 
1633 void sysctl_head_finish(struct ctl_table_header *head)
1634 {
1635 	if (!head)
1636 		return;
1637 	spin_lock(&sysctl_lock);
1638 	unuse_table(head);
1639 	spin_unlock(&sysctl_lock);
1640 }
1641 
1642 static struct ctl_table_set *
1643 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1644 {
1645 	struct ctl_table_set *set = &root->default_set;
1646 	if (root->lookup)
1647 		set = root->lookup(root, namespaces);
1648 	return set;
1649 }
1650 
1651 static struct list_head *
1652 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1653 {
1654 	struct ctl_table_set *set = lookup_header_set(root, namespaces);
1655 	return &set->list;
1656 }
1657 
1658 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1659 					    struct ctl_table_header *prev)
1660 {
1661 	struct ctl_table_root *root;
1662 	struct list_head *header_list;
1663 	struct ctl_table_header *head;
1664 	struct list_head *tmp;
1665 
1666 	spin_lock(&sysctl_lock);
1667 	if (prev) {
1668 		head = prev;
1669 		tmp = &prev->ctl_entry;
1670 		unuse_table(prev);
1671 		goto next;
1672 	}
1673 	tmp = &root_table_header.ctl_entry;
1674 	for (;;) {
1675 		head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1676 
1677 		if (!use_table(head))
1678 			goto next;
1679 		spin_unlock(&sysctl_lock);
1680 		return head;
1681 	next:
1682 		root = head->root;
1683 		tmp = tmp->next;
1684 		header_list = lookup_header_list(root, namespaces);
1685 		if (tmp != header_list)
1686 			continue;
1687 
1688 		do {
1689 			root = list_entry(root->root_list.next,
1690 					struct ctl_table_root, root_list);
1691 			if (root == &sysctl_table_root)
1692 				goto out;
1693 			header_list = lookup_header_list(root, namespaces);
1694 		} while (list_empty(header_list));
1695 		tmp = header_list->next;
1696 	}
1697 out:
1698 	spin_unlock(&sysctl_lock);
1699 	return NULL;
1700 }
1701 
1702 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1703 {
1704 	return __sysctl_head_next(current->nsproxy, prev);
1705 }
1706 
1707 void register_sysctl_root(struct ctl_table_root *root)
1708 {
1709 	spin_lock(&sysctl_lock);
1710 	list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1711 	spin_unlock(&sysctl_lock);
1712 }
1713 
1714 /*
1715  * sysctl_perm does NOT grant the superuser all rights automatically, because
1716  * some sysctl variables are readonly even to root.
1717  */
1718 
1719 static int test_perm(int mode, int op)
1720 {
1721 	if (!current_euid())
1722 		mode >>= 6;
1723 	else if (in_egroup_p(0))
1724 		mode >>= 3;
1725 	if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1726 		return 0;
1727 	return -EACCES;
1728 }
1729 
1730 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1731 {
1732 	int mode;
1733 
1734 	if (root->permissions)
1735 		mode = root->permissions(root, current->nsproxy, table);
1736 	else
1737 		mode = table->mode;
1738 
1739 	return test_perm(mode, op);
1740 }
1741 
1742 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1743 {
1744 	for (; table->procname; table++) {
1745 		table->parent = parent;
1746 		if (table->child)
1747 			sysctl_set_parent(table, table->child);
1748 	}
1749 }
1750 
1751 static __init int sysctl_init(void)
1752 {
1753 	sysctl_set_parent(NULL, root_table);
1754 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1755 	sysctl_check_table(current->nsproxy, root_table);
1756 #endif
1757 	return 0;
1758 }
1759 
1760 core_initcall(sysctl_init);
1761 
1762 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1763 				      struct ctl_table *table)
1764 {
1765 	struct ctl_table *p;
1766 	const char *s = branch->procname;
1767 
1768 	/* branch should have named subdirectory as its first element */
1769 	if (!s || !branch->child)
1770 		return NULL;
1771 
1772 	/* ... and nothing else */
1773 	if (branch[1].procname)
1774 		return NULL;
1775 
1776 	/* table should contain subdirectory with the same name */
1777 	for (p = table; p->procname; p++) {
1778 		if (!p->child)
1779 			continue;
1780 		if (p->procname && strcmp(p->procname, s) == 0)
1781 			return p;
1782 	}
1783 	return NULL;
1784 }
1785 
1786 /* see if attaching q to p would be an improvement */
1787 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1788 {
1789 	struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1790 	struct ctl_table *next;
1791 	int is_better = 0;
1792 	int not_in_parent = !p->attached_by;
1793 
1794 	while ((next = is_branch_in(by, to)) != NULL) {
1795 		if (by == q->attached_by)
1796 			is_better = 1;
1797 		if (to == p->attached_by)
1798 			not_in_parent = 1;
1799 		by = by->child;
1800 		to = next->child;
1801 	}
1802 
1803 	if (is_better && not_in_parent) {
1804 		q->attached_by = by;
1805 		q->attached_to = to;
1806 		q->parent = p;
1807 	}
1808 }
1809 
1810 /**
1811  * __register_sysctl_paths - register a sysctl hierarchy
1812  * @root: List of sysctl headers to register on
1813  * @namespaces: Data to compute which lists of sysctl entries are visible
1814  * @path: The path to the directory the sysctl table is in.
1815  * @table: the top-level table structure
1816  *
1817  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1818  * array. A completely 0 filled entry terminates the table.
1819  *
1820  * The members of the &struct ctl_table structure are used as follows:
1821  *
1822  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1823  *            enter a sysctl file
1824  *
1825  * data - a pointer to data for use by proc_handler
1826  *
1827  * maxlen - the maximum size in bytes of the data
1828  *
1829  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1830  *
1831  * child - a pointer to the child sysctl table if this entry is a directory, or
1832  *         %NULL.
1833  *
1834  * proc_handler - the text handler routine (described below)
1835  *
1836  * de - for internal use by the sysctl routines
1837  *
1838  * extra1, extra2 - extra pointers usable by the proc handler routines
1839  *
1840  * Leaf nodes in the sysctl tree will be represented by a single file
1841  * under /proc; non-leaf nodes will be represented by directories.
1842  *
1843  * sysctl(2) can automatically manage read and write requests through
1844  * the sysctl table.  The data and maxlen fields of the ctl_table
1845  * struct enable minimal validation of the values being written to be
1846  * performed, and the mode field allows minimal authentication.
1847  *
1848  * There must be a proc_handler routine for any terminal nodes
1849  * mirrored under /proc/sys (non-terminals are handled by a built-in
1850  * directory handler).  Several default handlers are available to
1851  * cover common cases -
1852  *
1853  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1854  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1855  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1856  *
1857  * It is the handler's job to read the input buffer from user memory
1858  * and process it. The handler should return 0 on success.
1859  *
1860  * This routine returns %NULL on a failure to register, and a pointer
1861  * to the table header on success.
1862  */
1863 struct ctl_table_header *__register_sysctl_paths(
1864 	struct ctl_table_root *root,
1865 	struct nsproxy *namespaces,
1866 	const struct ctl_path *path, struct ctl_table *table)
1867 {
1868 	struct ctl_table_header *header;
1869 	struct ctl_table *new, **prevp;
1870 	unsigned int n, npath;
1871 	struct ctl_table_set *set;
1872 
1873 	/* Count the path components */
1874 	for (npath = 0; path[npath].procname; ++npath)
1875 		;
1876 
1877 	/*
1878 	 * For each path component, allocate a 2-element ctl_table array.
1879 	 * The first array element will be filled with the sysctl entry
1880 	 * for this, the second will be the sentinel (procname == 0).
1881 	 *
1882 	 * We allocate everything in one go so that we don't have to
1883 	 * worry about freeing additional memory in unregister_sysctl_table.
1884 	 */
1885 	header = kzalloc(sizeof(struct ctl_table_header) +
1886 			 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1887 	if (!header)
1888 		return NULL;
1889 
1890 	new = (struct ctl_table *) (header + 1);
1891 
1892 	/* Now connect the dots */
1893 	prevp = &header->ctl_table;
1894 	for (n = 0; n < npath; ++n, ++path) {
1895 		/* Copy the procname */
1896 		new->procname = path->procname;
1897 		new->mode     = 0555;
1898 
1899 		*prevp = new;
1900 		prevp = &new->child;
1901 
1902 		new += 2;
1903 	}
1904 	*prevp = table;
1905 	header->ctl_table_arg = table;
1906 
1907 	INIT_LIST_HEAD(&header->ctl_entry);
1908 	header->used = 0;
1909 	header->unregistering = NULL;
1910 	header->root = root;
1911 	sysctl_set_parent(NULL, header->ctl_table);
1912 	header->count = 1;
1913 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1914 	if (sysctl_check_table(namespaces, header->ctl_table)) {
1915 		kfree(header);
1916 		return NULL;
1917 	}
1918 #endif
1919 	spin_lock(&sysctl_lock);
1920 	header->set = lookup_header_set(root, namespaces);
1921 	header->attached_by = header->ctl_table;
1922 	header->attached_to = root_table;
1923 	header->parent = &root_table_header;
1924 	for (set = header->set; set; set = set->parent) {
1925 		struct ctl_table_header *p;
1926 		list_for_each_entry(p, &set->list, ctl_entry) {
1927 			if (p->unregistering)
1928 				continue;
1929 			try_attach(p, header);
1930 		}
1931 	}
1932 	header->parent->count++;
1933 	list_add_tail(&header->ctl_entry, &header->set->list);
1934 	spin_unlock(&sysctl_lock);
1935 
1936 	return header;
1937 }
1938 
1939 /**
1940  * register_sysctl_table_path - register a sysctl table hierarchy
1941  * @path: The path to the directory the sysctl table is in.
1942  * @table: the top-level table structure
1943  *
1944  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1945  * array. A completely 0 filled entry terminates the table.
1946  *
1947  * See __register_sysctl_paths for more details.
1948  */
1949 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1950 						struct ctl_table *table)
1951 {
1952 	return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1953 					path, table);
1954 }
1955 
1956 /**
1957  * register_sysctl_table - register a sysctl table hierarchy
1958  * @table: the top-level table structure
1959  *
1960  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1961  * array. A completely 0 filled entry terminates the table.
1962  *
1963  * See register_sysctl_paths for more details.
1964  */
1965 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1966 {
1967 	static const struct ctl_path null_path[] = { {} };
1968 
1969 	return register_sysctl_paths(null_path, table);
1970 }
1971 
1972 /**
1973  * unregister_sysctl_table - unregister a sysctl table hierarchy
1974  * @header: the header returned from register_sysctl_table
1975  *
1976  * Unregisters the sysctl table and all children. proc entries may not
1977  * actually be removed until they are no longer used by anyone.
1978  */
1979 void unregister_sysctl_table(struct ctl_table_header * header)
1980 {
1981 	might_sleep();
1982 
1983 	if (header == NULL)
1984 		return;
1985 
1986 	spin_lock(&sysctl_lock);
1987 	start_unregistering(header);
1988 	if (!--header->parent->count) {
1989 		WARN_ON(1);
1990 		kfree_rcu(header->parent, rcu);
1991 	}
1992 	if (!--header->count)
1993 		kfree_rcu(header, rcu);
1994 	spin_unlock(&sysctl_lock);
1995 }
1996 
1997 int sysctl_is_seen(struct ctl_table_header *p)
1998 {
1999 	struct ctl_table_set *set = p->set;
2000 	int res;
2001 	spin_lock(&sysctl_lock);
2002 	if (p->unregistering)
2003 		res = 0;
2004 	else if (!set->is_seen)
2005 		res = 1;
2006 	else
2007 		res = set->is_seen(set);
2008 	spin_unlock(&sysctl_lock);
2009 	return res;
2010 }
2011 
2012 void setup_sysctl_set(struct ctl_table_set *p,
2013 	struct ctl_table_set *parent,
2014 	int (*is_seen)(struct ctl_table_set *))
2015 {
2016 	INIT_LIST_HEAD(&p->list);
2017 	p->parent = parent ? parent : &sysctl_table_root.default_set;
2018 	p->is_seen = is_seen;
2019 }
2020 
2021 #else /* !CONFIG_SYSCTL */
2022 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2023 {
2024 	return NULL;
2025 }
2026 
2027 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2028 						    struct ctl_table *table)
2029 {
2030 	return NULL;
2031 }
2032 
2033 void unregister_sysctl_table(struct ctl_table_header * table)
2034 {
2035 }
2036 
2037 void setup_sysctl_set(struct ctl_table_set *p,
2038 	struct ctl_table_set *parent,
2039 	int (*is_seen)(struct ctl_table_set *))
2040 {
2041 }
2042 
2043 void sysctl_head_put(struct ctl_table_header *head)
2044 {
2045 }
2046 
2047 #endif /* CONFIG_SYSCTL */
2048 
2049 /*
2050  * /proc/sys support
2051  */
2052 
2053 #ifdef CONFIG_PROC_SYSCTL
2054 
2055 static int _proc_do_string(void* data, int maxlen, int write,
2056 			   void __user *buffer,
2057 			   size_t *lenp, loff_t *ppos)
2058 {
2059 	size_t len;
2060 	char __user *p;
2061 	char c;
2062 
2063 	if (!data || !maxlen || !*lenp) {
2064 		*lenp = 0;
2065 		return 0;
2066 	}
2067 
2068 	if (write) {
2069 		len = 0;
2070 		p = buffer;
2071 		while (len < *lenp) {
2072 			if (get_user(c, p++))
2073 				return -EFAULT;
2074 			if (c == 0 || c == '\n')
2075 				break;
2076 			len++;
2077 		}
2078 		if (len >= maxlen)
2079 			len = maxlen-1;
2080 		if(copy_from_user(data, buffer, len))
2081 			return -EFAULT;
2082 		((char *) data)[len] = 0;
2083 		*ppos += *lenp;
2084 	} else {
2085 		len = strlen(data);
2086 		if (len > maxlen)
2087 			len = maxlen;
2088 
2089 		if (*ppos > len) {
2090 			*lenp = 0;
2091 			return 0;
2092 		}
2093 
2094 		data += *ppos;
2095 		len  -= *ppos;
2096 
2097 		if (len > *lenp)
2098 			len = *lenp;
2099 		if (len)
2100 			if(copy_to_user(buffer, data, len))
2101 				return -EFAULT;
2102 		if (len < *lenp) {
2103 			if(put_user('\n', ((char __user *) buffer) + len))
2104 				return -EFAULT;
2105 			len++;
2106 		}
2107 		*lenp = len;
2108 		*ppos += len;
2109 	}
2110 	return 0;
2111 }
2112 
2113 /**
2114  * proc_dostring - read a string sysctl
2115  * @table: the sysctl table
2116  * @write: %TRUE if this is a write to the sysctl file
2117  * @buffer: the user buffer
2118  * @lenp: the size of the user buffer
2119  * @ppos: file position
2120  *
2121  * Reads/writes a string from/to the user buffer. If the kernel
2122  * buffer provided is not large enough to hold the string, the
2123  * string is truncated. The copied string is %NULL-terminated.
2124  * If the string is being read by the user process, it is copied
2125  * and a newline '\n' is added. It is truncated if the buffer is
2126  * not large enough.
2127  *
2128  * Returns 0 on success.
2129  */
2130 int proc_dostring(struct ctl_table *table, int write,
2131 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2132 {
2133 	return _proc_do_string(table->data, table->maxlen, write,
2134 			       buffer, lenp, ppos);
2135 }
2136 
2137 static size_t proc_skip_spaces(char **buf)
2138 {
2139 	size_t ret;
2140 	char *tmp = skip_spaces(*buf);
2141 	ret = tmp - *buf;
2142 	*buf = tmp;
2143 	return ret;
2144 }
2145 
2146 static void proc_skip_char(char **buf, size_t *size, const char v)
2147 {
2148 	while (*size) {
2149 		if (**buf != v)
2150 			break;
2151 		(*size)--;
2152 		(*buf)++;
2153 	}
2154 }
2155 
2156 #define TMPBUFLEN 22
2157 /**
2158  * proc_get_long - reads an ASCII formatted integer from a user buffer
2159  *
2160  * @buf: a kernel buffer
2161  * @size: size of the kernel buffer
2162  * @val: this is where the number will be stored
2163  * @neg: set to %TRUE if number is negative
2164  * @perm_tr: a vector which contains the allowed trailers
2165  * @perm_tr_len: size of the perm_tr vector
2166  * @tr: pointer to store the trailer character
2167  *
2168  * In case of success %0 is returned and @buf and @size are updated with
2169  * the amount of bytes read. If @tr is non-NULL and a trailing
2170  * character exists (size is non-zero after returning from this
2171  * function), @tr is updated with the trailing character.
2172  */
2173 static int proc_get_long(char **buf, size_t *size,
2174 			  unsigned long *val, bool *neg,
2175 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2176 {
2177 	int len;
2178 	char *p, tmp[TMPBUFLEN];
2179 
2180 	if (!*size)
2181 		return -EINVAL;
2182 
2183 	len = *size;
2184 	if (len > TMPBUFLEN - 1)
2185 		len = TMPBUFLEN - 1;
2186 
2187 	memcpy(tmp, *buf, len);
2188 
2189 	tmp[len] = 0;
2190 	p = tmp;
2191 	if (*p == '-' && *size > 1) {
2192 		*neg = true;
2193 		p++;
2194 	} else
2195 		*neg = false;
2196 	if (!isdigit(*p))
2197 		return -EINVAL;
2198 
2199 	*val = simple_strtoul(p, &p, 0);
2200 
2201 	len = p - tmp;
2202 
2203 	/* We don't know if the next char is whitespace thus we may accept
2204 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2205 	 * (e.g. 123...1). So lets not allow such large numbers. */
2206 	if (len == TMPBUFLEN - 1)
2207 		return -EINVAL;
2208 
2209 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2210 		return -EINVAL;
2211 
2212 	if (tr && (len < *size))
2213 		*tr = *p;
2214 
2215 	*buf += len;
2216 	*size -= len;
2217 
2218 	return 0;
2219 }
2220 
2221 /**
2222  * proc_put_long - converts an integer to a decimal ASCII formatted string
2223  *
2224  * @buf: the user buffer
2225  * @size: the size of the user buffer
2226  * @val: the integer to be converted
2227  * @neg: sign of the number, %TRUE for negative
2228  *
2229  * In case of success %0 is returned and @buf and @size are updated with
2230  * the amount of bytes written.
2231  */
2232 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2233 			  bool neg)
2234 {
2235 	int len;
2236 	char tmp[TMPBUFLEN], *p = tmp;
2237 
2238 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2239 	len = strlen(tmp);
2240 	if (len > *size)
2241 		len = *size;
2242 	if (copy_to_user(*buf, tmp, len))
2243 		return -EFAULT;
2244 	*size -= len;
2245 	*buf += len;
2246 	return 0;
2247 }
2248 #undef TMPBUFLEN
2249 
2250 static int proc_put_char(void __user **buf, size_t *size, char c)
2251 {
2252 	if (*size) {
2253 		char __user **buffer = (char __user **)buf;
2254 		if (put_user(c, *buffer))
2255 			return -EFAULT;
2256 		(*size)--, (*buffer)++;
2257 		*buf = *buffer;
2258 	}
2259 	return 0;
2260 }
2261 
2262 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2263 				 int *valp,
2264 				 int write, void *data)
2265 {
2266 	if (write) {
2267 		*valp = *negp ? -*lvalp : *lvalp;
2268 	} else {
2269 		int val = *valp;
2270 		if (val < 0) {
2271 			*negp = true;
2272 			*lvalp = (unsigned long)-val;
2273 		} else {
2274 			*negp = false;
2275 			*lvalp = (unsigned long)val;
2276 		}
2277 	}
2278 	return 0;
2279 }
2280 
2281 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2282 
2283 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2284 		  int write, void __user *buffer,
2285 		  size_t *lenp, loff_t *ppos,
2286 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2287 			      int write, void *data),
2288 		  void *data)
2289 {
2290 	int *i, vleft, first = 1, err = 0;
2291 	unsigned long page = 0;
2292 	size_t left;
2293 	char *kbuf;
2294 
2295 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2296 		*lenp = 0;
2297 		return 0;
2298 	}
2299 
2300 	i = (int *) tbl_data;
2301 	vleft = table->maxlen / sizeof(*i);
2302 	left = *lenp;
2303 
2304 	if (!conv)
2305 		conv = do_proc_dointvec_conv;
2306 
2307 	if (write) {
2308 		if (left > PAGE_SIZE - 1)
2309 			left = PAGE_SIZE - 1;
2310 		page = __get_free_page(GFP_TEMPORARY);
2311 		kbuf = (char *) page;
2312 		if (!kbuf)
2313 			return -ENOMEM;
2314 		if (copy_from_user(kbuf, buffer, left)) {
2315 			err = -EFAULT;
2316 			goto free;
2317 		}
2318 		kbuf[left] = 0;
2319 	}
2320 
2321 	for (; left && vleft--; i++, first=0) {
2322 		unsigned long lval;
2323 		bool neg;
2324 
2325 		if (write) {
2326 			left -= proc_skip_spaces(&kbuf);
2327 
2328 			if (!left)
2329 				break;
2330 			err = proc_get_long(&kbuf, &left, &lval, &neg,
2331 					     proc_wspace_sep,
2332 					     sizeof(proc_wspace_sep), NULL);
2333 			if (err)
2334 				break;
2335 			if (conv(&neg, &lval, i, 1, data)) {
2336 				err = -EINVAL;
2337 				break;
2338 			}
2339 		} else {
2340 			if (conv(&neg, &lval, i, 0, data)) {
2341 				err = -EINVAL;
2342 				break;
2343 			}
2344 			if (!first)
2345 				err = proc_put_char(&buffer, &left, '\t');
2346 			if (err)
2347 				break;
2348 			err = proc_put_long(&buffer, &left, lval, neg);
2349 			if (err)
2350 				break;
2351 		}
2352 	}
2353 
2354 	if (!write && !first && left && !err)
2355 		err = proc_put_char(&buffer, &left, '\n');
2356 	if (write && !err && left)
2357 		left -= proc_skip_spaces(&kbuf);
2358 free:
2359 	if (write) {
2360 		free_page(page);
2361 		if (first)
2362 			return err ? : -EINVAL;
2363 	}
2364 	*lenp -= left;
2365 	*ppos += *lenp;
2366 	return err;
2367 }
2368 
2369 static int do_proc_dointvec(struct ctl_table *table, int write,
2370 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2371 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2372 			      int write, void *data),
2373 		  void *data)
2374 {
2375 	return __do_proc_dointvec(table->data, table, write,
2376 			buffer, lenp, ppos, conv, data);
2377 }
2378 
2379 /**
2380  * proc_dointvec - read a vector of integers
2381  * @table: the sysctl table
2382  * @write: %TRUE if this is a write to the sysctl file
2383  * @buffer: the user buffer
2384  * @lenp: the size of the user buffer
2385  * @ppos: file position
2386  *
2387  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2388  * values from/to the user buffer, treated as an ASCII string.
2389  *
2390  * Returns 0 on success.
2391  */
2392 int proc_dointvec(struct ctl_table *table, int write,
2393 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2394 {
2395     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2396 		    	    NULL,NULL);
2397 }
2398 
2399 /*
2400  * Taint values can only be increased
2401  * This means we can safely use a temporary.
2402  */
2403 static int proc_taint(struct ctl_table *table, int write,
2404 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2405 {
2406 	struct ctl_table t;
2407 	unsigned long tmptaint = get_taint();
2408 	int err;
2409 
2410 	if (write && !capable(CAP_SYS_ADMIN))
2411 		return -EPERM;
2412 
2413 	t = *table;
2414 	t.data = &tmptaint;
2415 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2416 	if (err < 0)
2417 		return err;
2418 
2419 	if (write) {
2420 		/*
2421 		 * Poor man's atomic or. Not worth adding a primitive
2422 		 * to everyone's atomic.h for this
2423 		 */
2424 		int i;
2425 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2426 			if ((tmptaint >> i) & 1)
2427 				add_taint(i);
2428 		}
2429 	}
2430 
2431 	return err;
2432 }
2433 
2434 #ifdef CONFIG_PRINTK
2435 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2436 				void __user *buffer, size_t *lenp, loff_t *ppos)
2437 {
2438 	if (write && !capable(CAP_SYS_ADMIN))
2439 		return -EPERM;
2440 
2441 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2442 }
2443 #endif
2444 
2445 struct do_proc_dointvec_minmax_conv_param {
2446 	int *min;
2447 	int *max;
2448 };
2449 
2450 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2451 					int *valp,
2452 					int write, void *data)
2453 {
2454 	struct do_proc_dointvec_minmax_conv_param *param = data;
2455 	if (write) {
2456 		int val = *negp ? -*lvalp : *lvalp;
2457 		if ((param->min && *param->min > val) ||
2458 		    (param->max && *param->max < val))
2459 			return -EINVAL;
2460 		*valp = val;
2461 	} else {
2462 		int val = *valp;
2463 		if (val < 0) {
2464 			*negp = true;
2465 			*lvalp = (unsigned long)-val;
2466 		} else {
2467 			*negp = false;
2468 			*lvalp = (unsigned long)val;
2469 		}
2470 	}
2471 	return 0;
2472 }
2473 
2474 /**
2475  * proc_dointvec_minmax - read a vector of integers with min/max values
2476  * @table: the sysctl table
2477  * @write: %TRUE if this is a write to the sysctl file
2478  * @buffer: the user buffer
2479  * @lenp: the size of the user buffer
2480  * @ppos: file position
2481  *
2482  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2483  * values from/to the user buffer, treated as an ASCII string.
2484  *
2485  * This routine will ensure the values are within the range specified by
2486  * table->extra1 (min) and table->extra2 (max).
2487  *
2488  * Returns 0 on success.
2489  */
2490 int proc_dointvec_minmax(struct ctl_table *table, int write,
2491 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2492 {
2493 	struct do_proc_dointvec_minmax_conv_param param = {
2494 		.min = (int *) table->extra1,
2495 		.max = (int *) table->extra2,
2496 	};
2497 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2498 				do_proc_dointvec_minmax_conv, &param);
2499 }
2500 
2501 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2502 				     void __user *buffer,
2503 				     size_t *lenp, loff_t *ppos,
2504 				     unsigned long convmul,
2505 				     unsigned long convdiv)
2506 {
2507 	unsigned long *i, *min, *max;
2508 	int vleft, first = 1, err = 0;
2509 	unsigned long page = 0;
2510 	size_t left;
2511 	char *kbuf;
2512 
2513 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2514 		*lenp = 0;
2515 		return 0;
2516 	}
2517 
2518 	i = (unsigned long *) data;
2519 	min = (unsigned long *) table->extra1;
2520 	max = (unsigned long *) table->extra2;
2521 	vleft = table->maxlen / sizeof(unsigned long);
2522 	left = *lenp;
2523 
2524 	if (write) {
2525 		if (left > PAGE_SIZE - 1)
2526 			left = PAGE_SIZE - 1;
2527 		page = __get_free_page(GFP_TEMPORARY);
2528 		kbuf = (char *) page;
2529 		if (!kbuf)
2530 			return -ENOMEM;
2531 		if (copy_from_user(kbuf, buffer, left)) {
2532 			err = -EFAULT;
2533 			goto free;
2534 		}
2535 		kbuf[left] = 0;
2536 	}
2537 
2538 	for (; left && vleft--; i++, first = 0) {
2539 		unsigned long val;
2540 
2541 		if (write) {
2542 			bool neg;
2543 
2544 			left -= proc_skip_spaces(&kbuf);
2545 
2546 			err = proc_get_long(&kbuf, &left, &val, &neg,
2547 					     proc_wspace_sep,
2548 					     sizeof(proc_wspace_sep), NULL);
2549 			if (err)
2550 				break;
2551 			if (neg)
2552 				continue;
2553 			if ((min && val < *min) || (max && val > *max))
2554 				continue;
2555 			*i = val;
2556 		} else {
2557 			val = convdiv * (*i) / convmul;
2558 			if (!first)
2559 				err = proc_put_char(&buffer, &left, '\t');
2560 			err = proc_put_long(&buffer, &left, val, false);
2561 			if (err)
2562 				break;
2563 		}
2564 	}
2565 
2566 	if (!write && !first && left && !err)
2567 		err = proc_put_char(&buffer, &left, '\n');
2568 	if (write && !err)
2569 		left -= proc_skip_spaces(&kbuf);
2570 free:
2571 	if (write) {
2572 		free_page(page);
2573 		if (first)
2574 			return err ? : -EINVAL;
2575 	}
2576 	*lenp -= left;
2577 	*ppos += *lenp;
2578 	return err;
2579 }
2580 
2581 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2582 				     void __user *buffer,
2583 				     size_t *lenp, loff_t *ppos,
2584 				     unsigned long convmul,
2585 				     unsigned long convdiv)
2586 {
2587 	return __do_proc_doulongvec_minmax(table->data, table, write,
2588 			buffer, lenp, ppos, convmul, convdiv);
2589 }
2590 
2591 /**
2592  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2593  * @table: the sysctl table
2594  * @write: %TRUE if this is a write to the sysctl file
2595  * @buffer: the user buffer
2596  * @lenp: the size of the user buffer
2597  * @ppos: file position
2598  *
2599  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2600  * values from/to the user buffer, treated as an ASCII string.
2601  *
2602  * This routine will ensure the values are within the range specified by
2603  * table->extra1 (min) and table->extra2 (max).
2604  *
2605  * Returns 0 on success.
2606  */
2607 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2608 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2609 {
2610     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2611 }
2612 
2613 /**
2614  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2615  * @table: the sysctl table
2616  * @write: %TRUE if this is a write to the sysctl file
2617  * @buffer: the user buffer
2618  * @lenp: the size of the user buffer
2619  * @ppos: file position
2620  *
2621  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2622  * values from/to the user buffer, treated as an ASCII string. The values
2623  * are treated as milliseconds, and converted to jiffies when they are stored.
2624  *
2625  * This routine will ensure the values are within the range specified by
2626  * table->extra1 (min) and table->extra2 (max).
2627  *
2628  * Returns 0 on success.
2629  */
2630 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2631 				      void __user *buffer,
2632 				      size_t *lenp, loff_t *ppos)
2633 {
2634     return do_proc_doulongvec_minmax(table, write, buffer,
2635 				     lenp, ppos, HZ, 1000l);
2636 }
2637 
2638 
2639 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2640 					 int *valp,
2641 					 int write, void *data)
2642 {
2643 	if (write) {
2644 		if (*lvalp > LONG_MAX / HZ)
2645 			return 1;
2646 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2647 	} else {
2648 		int val = *valp;
2649 		unsigned long lval;
2650 		if (val < 0) {
2651 			*negp = true;
2652 			lval = (unsigned long)-val;
2653 		} else {
2654 			*negp = false;
2655 			lval = (unsigned long)val;
2656 		}
2657 		*lvalp = lval / HZ;
2658 	}
2659 	return 0;
2660 }
2661 
2662 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2663 						int *valp,
2664 						int write, void *data)
2665 {
2666 	if (write) {
2667 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2668 			return 1;
2669 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2670 	} else {
2671 		int val = *valp;
2672 		unsigned long lval;
2673 		if (val < 0) {
2674 			*negp = true;
2675 			lval = (unsigned long)-val;
2676 		} else {
2677 			*negp = false;
2678 			lval = (unsigned long)val;
2679 		}
2680 		*lvalp = jiffies_to_clock_t(lval);
2681 	}
2682 	return 0;
2683 }
2684 
2685 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2686 					    int *valp,
2687 					    int write, void *data)
2688 {
2689 	if (write) {
2690 		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2691 	} else {
2692 		int val = *valp;
2693 		unsigned long lval;
2694 		if (val < 0) {
2695 			*negp = true;
2696 			lval = (unsigned long)-val;
2697 		} else {
2698 			*negp = false;
2699 			lval = (unsigned long)val;
2700 		}
2701 		*lvalp = jiffies_to_msecs(lval);
2702 	}
2703 	return 0;
2704 }
2705 
2706 /**
2707  * proc_dointvec_jiffies - read a vector of integers as seconds
2708  * @table: the sysctl table
2709  * @write: %TRUE if this is a write to the sysctl file
2710  * @buffer: the user buffer
2711  * @lenp: the size of the user buffer
2712  * @ppos: file position
2713  *
2714  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715  * values from/to the user buffer, treated as an ASCII string.
2716  * The values read are assumed to be in seconds, and are converted into
2717  * jiffies.
2718  *
2719  * Returns 0 on success.
2720  */
2721 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2722 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2723 {
2724     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2725 		    	    do_proc_dointvec_jiffies_conv,NULL);
2726 }
2727 
2728 /**
2729  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2730  * @table: the sysctl table
2731  * @write: %TRUE if this is a write to the sysctl file
2732  * @buffer: the user buffer
2733  * @lenp: the size of the user buffer
2734  * @ppos: pointer to the file position
2735  *
2736  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2737  * values from/to the user buffer, treated as an ASCII string.
2738  * The values read are assumed to be in 1/USER_HZ seconds, and
2739  * are converted into jiffies.
2740  *
2741  * Returns 0 on success.
2742  */
2743 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2744 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2745 {
2746     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2747 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2748 }
2749 
2750 /**
2751  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2752  * @table: the sysctl table
2753  * @write: %TRUE if this is a write to the sysctl file
2754  * @buffer: the user buffer
2755  * @lenp: the size of the user buffer
2756  * @ppos: file position
2757  * @ppos: the current position in the file
2758  *
2759  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2760  * values from/to the user buffer, treated as an ASCII string.
2761  * The values read are assumed to be in 1/1000 seconds, and
2762  * are converted into jiffies.
2763  *
2764  * Returns 0 on success.
2765  */
2766 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2767 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2768 {
2769 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2770 				do_proc_dointvec_ms_jiffies_conv, NULL);
2771 }
2772 
2773 static int proc_do_cad_pid(struct ctl_table *table, int write,
2774 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2775 {
2776 	struct pid *new_pid;
2777 	pid_t tmp;
2778 	int r;
2779 
2780 	tmp = pid_vnr(cad_pid);
2781 
2782 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2783 			       lenp, ppos, NULL, NULL);
2784 	if (r || !write)
2785 		return r;
2786 
2787 	new_pid = find_get_pid(tmp);
2788 	if (!new_pid)
2789 		return -ESRCH;
2790 
2791 	put_pid(xchg(&cad_pid, new_pid));
2792 	return 0;
2793 }
2794 
2795 /**
2796  * proc_do_large_bitmap - read/write from/to a large bitmap
2797  * @table: the sysctl table
2798  * @write: %TRUE if this is a write to the sysctl file
2799  * @buffer: the user buffer
2800  * @lenp: the size of the user buffer
2801  * @ppos: file position
2802  *
2803  * The bitmap is stored at table->data and the bitmap length (in bits)
2804  * in table->maxlen.
2805  *
2806  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2807  * large bitmaps may be represented in a compact manner. Writing into
2808  * the file will clear the bitmap then update it with the given input.
2809  *
2810  * Returns 0 on success.
2811  */
2812 int proc_do_large_bitmap(struct ctl_table *table, int write,
2813 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2814 {
2815 	int err = 0;
2816 	bool first = 1;
2817 	size_t left = *lenp;
2818 	unsigned long bitmap_len = table->maxlen;
2819 	unsigned long *bitmap = (unsigned long *) table->data;
2820 	unsigned long *tmp_bitmap = NULL;
2821 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2822 
2823 	if (!bitmap_len || !left || (*ppos && !write)) {
2824 		*lenp = 0;
2825 		return 0;
2826 	}
2827 
2828 	if (write) {
2829 		unsigned long page = 0;
2830 		char *kbuf;
2831 
2832 		if (left > PAGE_SIZE - 1)
2833 			left = PAGE_SIZE - 1;
2834 
2835 		page = __get_free_page(GFP_TEMPORARY);
2836 		kbuf = (char *) page;
2837 		if (!kbuf)
2838 			return -ENOMEM;
2839 		if (copy_from_user(kbuf, buffer, left)) {
2840 			free_page(page);
2841 			return -EFAULT;
2842                 }
2843 		kbuf[left] = 0;
2844 
2845 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2846 				     GFP_KERNEL);
2847 		if (!tmp_bitmap) {
2848 			free_page(page);
2849 			return -ENOMEM;
2850 		}
2851 		proc_skip_char(&kbuf, &left, '\n');
2852 		while (!err && left) {
2853 			unsigned long val_a, val_b;
2854 			bool neg;
2855 
2856 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2857 					     sizeof(tr_a), &c);
2858 			if (err)
2859 				break;
2860 			if (val_a >= bitmap_len || neg) {
2861 				err = -EINVAL;
2862 				break;
2863 			}
2864 
2865 			val_b = val_a;
2866 			if (left) {
2867 				kbuf++;
2868 				left--;
2869 			}
2870 
2871 			if (c == '-') {
2872 				err = proc_get_long(&kbuf, &left, &val_b,
2873 						     &neg, tr_b, sizeof(tr_b),
2874 						     &c);
2875 				if (err)
2876 					break;
2877 				if (val_b >= bitmap_len || neg ||
2878 				    val_a > val_b) {
2879 					err = -EINVAL;
2880 					break;
2881 				}
2882 				if (left) {
2883 					kbuf++;
2884 					left--;
2885 				}
2886 			}
2887 
2888 			while (val_a <= val_b)
2889 				set_bit(val_a++, tmp_bitmap);
2890 
2891 			first = 0;
2892 			proc_skip_char(&kbuf, &left, '\n');
2893 		}
2894 		free_page(page);
2895 	} else {
2896 		unsigned long bit_a, bit_b = 0;
2897 
2898 		while (left) {
2899 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2900 			if (bit_a >= bitmap_len)
2901 				break;
2902 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2903 						   bit_a + 1) - 1;
2904 
2905 			if (!first) {
2906 				err = proc_put_char(&buffer, &left, ',');
2907 				if (err)
2908 					break;
2909 			}
2910 			err = proc_put_long(&buffer, &left, bit_a, false);
2911 			if (err)
2912 				break;
2913 			if (bit_a != bit_b) {
2914 				err = proc_put_char(&buffer, &left, '-');
2915 				if (err)
2916 					break;
2917 				err = proc_put_long(&buffer, &left, bit_b, false);
2918 				if (err)
2919 					break;
2920 			}
2921 
2922 			first = 0; bit_b++;
2923 		}
2924 		if (!err)
2925 			err = proc_put_char(&buffer, &left, '\n');
2926 	}
2927 
2928 	if (!err) {
2929 		if (write) {
2930 			if (*ppos)
2931 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2932 			else
2933 				memcpy(bitmap, tmp_bitmap,
2934 					BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2935 		}
2936 		kfree(tmp_bitmap);
2937 		*lenp -= left;
2938 		*ppos += *lenp;
2939 		return 0;
2940 	} else {
2941 		kfree(tmp_bitmap);
2942 		return err;
2943 	}
2944 }
2945 
2946 #else /* CONFIG_PROC_SYSCTL */
2947 
2948 int proc_dostring(struct ctl_table *table, int write,
2949 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2950 {
2951 	return -ENOSYS;
2952 }
2953 
2954 int proc_dointvec(struct ctl_table *table, int write,
2955 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2956 {
2957 	return -ENOSYS;
2958 }
2959 
2960 int proc_dointvec_minmax(struct ctl_table *table, int write,
2961 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2962 {
2963 	return -ENOSYS;
2964 }
2965 
2966 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2967 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2968 {
2969 	return -ENOSYS;
2970 }
2971 
2972 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2973 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2974 {
2975 	return -ENOSYS;
2976 }
2977 
2978 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2979 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2980 {
2981 	return -ENOSYS;
2982 }
2983 
2984 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2985 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2986 {
2987 	return -ENOSYS;
2988 }
2989 
2990 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2991 				      void __user *buffer,
2992 				      size_t *lenp, loff_t *ppos)
2993 {
2994     return -ENOSYS;
2995 }
2996 
2997 
2998 #endif /* CONFIG_PROC_SYSCTL */
2999 
3000 /*
3001  * No sense putting this after each symbol definition, twice,
3002  * exception granted :-)
3003  */
3004 EXPORT_SYMBOL(proc_dointvec);
3005 EXPORT_SYMBOL(proc_dointvec_jiffies);
3006 EXPORT_SYMBOL(proc_dointvec_minmax);
3007 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3008 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3009 EXPORT_SYMBOL(proc_dostring);
3010 EXPORT_SYMBOL(proc_doulongvec_minmax);
3011 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3012 EXPORT_SYMBOL(register_sysctl_table);
3013 EXPORT_SYMBOL(register_sysctl_paths);
3014 EXPORT_SYMBOL(unregister_sysctl_table);
3015