xref: /linux/kernel/sysctl.c (revision 424f0750edd5af866f80f5e65998e0610503cb5c)
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 
62 #include <asm/uaccess.h>
63 #include <asm/processor.h>
64 
65 #ifdef CONFIG_X86
66 #include <asm/nmi.h>
67 #include <asm/stacktrace.h>
68 #include <asm/io.h>
69 #endif
70 #ifdef CONFIG_BSD_PROCESS_ACCT
71 #include <linux/acct.h>
72 #endif
73 #ifdef CONFIG_RT_MUTEXES
74 #include <linux/rtmutex.h>
75 #endif
76 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
77 #include <linux/lockdep.h>
78 #endif
79 #ifdef CONFIG_CHR_DEV_SG
80 #include <scsi/sg.h>
81 #endif
82 
83 #ifdef CONFIG_LOCKUP_DETECTOR
84 #include <linux/nmi.h>
85 #endif
86 
87 
88 #if defined(CONFIG_SYSCTL)
89 
90 /* External variables not in a header file. */
91 extern int sysctl_overcommit_memory;
92 extern int sysctl_overcommit_ratio;
93 extern int max_threads;
94 extern int core_uses_pid;
95 extern int suid_dumpable;
96 extern char core_pattern[];
97 extern unsigned int core_pipe_limit;
98 extern int pid_max;
99 extern int min_free_kbytes;
100 extern int pid_max_min, pid_max_max;
101 extern int sysctl_drop_caches;
102 extern int percpu_pagelist_fraction;
103 extern int compat_log;
104 extern int latencytop_enabled;
105 extern int sysctl_nr_open_min, sysctl_nr_open_max;
106 #ifndef CONFIG_MMU
107 extern int sysctl_nr_trim_pages;
108 #endif
109 #ifdef CONFIG_BLOCK
110 extern int blk_iopoll_enabled;
111 #endif
112 
113 /* Constants used for minimum and  maximum */
114 #ifdef CONFIG_LOCKUP_DETECTOR
115 static int sixty = 60;
116 static int neg_one = -1;
117 #endif
118 
119 static int zero;
120 static int __maybe_unused one = 1;
121 static int __maybe_unused two = 2;
122 static int __maybe_unused three = 3;
123 static unsigned long one_ul = 1;
124 static int one_hundred = 100;
125 #ifdef CONFIG_PRINTK
126 static int ten_thousand = 10000;
127 #endif
128 
129 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
130 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
131 
132 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
133 static int maxolduid = 65535;
134 static int minolduid;
135 static int min_percpu_pagelist_fract = 8;
136 
137 static int ngroups_max = NGROUPS_MAX;
138 static const int cap_last_cap = CAP_LAST_CAP;
139 
140 #ifdef CONFIG_INOTIFY_USER
141 #include <linux/inotify.h>
142 #endif
143 #ifdef CONFIG_SPARC
144 #include <asm/system.h>
145 #endif
146 
147 #ifdef CONFIG_SPARC64
148 extern int sysctl_tsb_ratio;
149 #endif
150 
151 #ifdef __hppa__
152 extern int pwrsw_enabled;
153 extern int unaligned_enabled;
154 #endif
155 
156 #ifdef CONFIG_IA64
157 extern int no_unaligned_warning;
158 extern int unaligned_dump_stack;
159 #endif
160 
161 #ifdef CONFIG_PROC_SYSCTL
162 static int proc_do_cad_pid(struct ctl_table *table, int write,
163 		  void __user *buffer, size_t *lenp, loff_t *ppos);
164 static int proc_taint(struct ctl_table *table, int write,
165 			       void __user *buffer, size_t *lenp, loff_t *ppos);
166 #endif
167 
168 #ifdef CONFIG_PRINTK
169 static int proc_dmesg_restrict(struct ctl_table *table, int write,
170 				void __user *buffer, size_t *lenp, loff_t *ppos);
171 #endif
172 
173 #ifdef CONFIG_MAGIC_SYSRQ
174 /* Note: sysrq code uses it's own private copy */
175 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
176 
177 static int sysrq_sysctl_handler(ctl_table *table, int write,
178 				void __user *buffer, size_t *lenp,
179 				loff_t *ppos)
180 {
181 	int error;
182 
183 	error = proc_dointvec(table, write, buffer, lenp, ppos);
184 	if (error)
185 		return error;
186 
187 	if (write)
188 		sysrq_toggle_support(__sysrq_enabled);
189 
190 	return 0;
191 }
192 
193 #endif
194 
195 static struct ctl_table root_table[];
196 static struct ctl_table_root sysctl_table_root;
197 static struct ctl_table_header root_table_header = {
198 	{{.count = 1,
199 	.ctl_table = root_table,
200 	.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
201 	.root = &sysctl_table_root,
202 	.set = &sysctl_table_root.default_set,
203 };
204 static struct ctl_table_root sysctl_table_root = {
205 	.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
206 	.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
207 };
208 
209 static struct ctl_table kern_table[];
210 static struct ctl_table vm_table[];
211 static struct ctl_table fs_table[];
212 static struct ctl_table debug_table[];
213 static struct ctl_table dev_table[];
214 extern struct ctl_table random_table[];
215 #ifdef CONFIG_EPOLL
216 extern struct ctl_table epoll_table[];
217 #endif
218 
219 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
220 int sysctl_legacy_va_layout;
221 #endif
222 
223 /* The default sysctl tables: */
224 
225 static struct ctl_table root_table[] = {
226 	{
227 		.procname	= "kernel",
228 		.mode		= 0555,
229 		.child		= kern_table,
230 	},
231 	{
232 		.procname	= "vm",
233 		.mode		= 0555,
234 		.child		= vm_table,
235 	},
236 	{
237 		.procname	= "fs",
238 		.mode		= 0555,
239 		.child		= fs_table,
240 	},
241 	{
242 		.procname	= "debug",
243 		.mode		= 0555,
244 		.child		= debug_table,
245 	},
246 	{
247 		.procname	= "dev",
248 		.mode		= 0555,
249 		.child		= dev_table,
250 	},
251 	{ }
252 };
253 
254 #ifdef CONFIG_SCHED_DEBUG
255 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
256 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
257 static int min_wakeup_granularity_ns;			/* 0 usecs */
258 static int max_wakeup_granularity_ns = NSEC_PER_SEC;	/* 1 second */
259 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
260 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
261 #endif
262 
263 #ifdef CONFIG_COMPACTION
264 static int min_extfrag_threshold;
265 static int max_extfrag_threshold = 1000;
266 #endif
267 
268 static struct ctl_table kern_table[] = {
269 	{
270 		.procname	= "sched_child_runs_first",
271 		.data		= &sysctl_sched_child_runs_first,
272 		.maxlen		= sizeof(unsigned int),
273 		.mode		= 0644,
274 		.proc_handler	= proc_dointvec,
275 	},
276 #ifdef CONFIG_SCHED_DEBUG
277 	{
278 		.procname	= "sched_min_granularity_ns",
279 		.data		= &sysctl_sched_min_granularity,
280 		.maxlen		= sizeof(unsigned int),
281 		.mode		= 0644,
282 		.proc_handler	= sched_proc_update_handler,
283 		.extra1		= &min_sched_granularity_ns,
284 		.extra2		= &max_sched_granularity_ns,
285 	},
286 	{
287 		.procname	= "sched_latency_ns",
288 		.data		= &sysctl_sched_latency,
289 		.maxlen		= sizeof(unsigned int),
290 		.mode		= 0644,
291 		.proc_handler	= sched_proc_update_handler,
292 		.extra1		= &min_sched_granularity_ns,
293 		.extra2		= &max_sched_granularity_ns,
294 	},
295 	{
296 		.procname	= "sched_wakeup_granularity_ns",
297 		.data		= &sysctl_sched_wakeup_granularity,
298 		.maxlen		= sizeof(unsigned int),
299 		.mode		= 0644,
300 		.proc_handler	= sched_proc_update_handler,
301 		.extra1		= &min_wakeup_granularity_ns,
302 		.extra2		= &max_wakeup_granularity_ns,
303 	},
304 	{
305 		.procname	= "sched_tunable_scaling",
306 		.data		= &sysctl_sched_tunable_scaling,
307 		.maxlen		= sizeof(enum sched_tunable_scaling),
308 		.mode		= 0644,
309 		.proc_handler	= sched_proc_update_handler,
310 		.extra1		= &min_sched_tunable_scaling,
311 		.extra2		= &max_sched_tunable_scaling,
312 	},
313 	{
314 		.procname	= "sched_migration_cost",
315 		.data		= &sysctl_sched_migration_cost,
316 		.maxlen		= sizeof(unsigned int),
317 		.mode		= 0644,
318 		.proc_handler	= proc_dointvec,
319 	},
320 	{
321 		.procname	= "sched_nr_migrate",
322 		.data		= &sysctl_sched_nr_migrate,
323 		.maxlen		= sizeof(unsigned int),
324 		.mode		= 0644,
325 		.proc_handler	= proc_dointvec,
326 	},
327 	{
328 		.procname	= "sched_time_avg",
329 		.data		= &sysctl_sched_time_avg,
330 		.maxlen		= sizeof(unsigned int),
331 		.mode		= 0644,
332 		.proc_handler	= proc_dointvec,
333 	},
334 	{
335 		.procname	= "sched_shares_window",
336 		.data		= &sysctl_sched_shares_window,
337 		.maxlen		= sizeof(unsigned int),
338 		.mode		= 0644,
339 		.proc_handler	= proc_dointvec,
340 	},
341 	{
342 		.procname	= "timer_migration",
343 		.data		= &sysctl_timer_migration,
344 		.maxlen		= sizeof(unsigned int),
345 		.mode		= 0644,
346 		.proc_handler	= proc_dointvec_minmax,
347 		.extra1		= &zero,
348 		.extra2		= &one,
349 	},
350 #endif
351 	{
352 		.procname	= "sched_rt_period_us",
353 		.data		= &sysctl_sched_rt_period,
354 		.maxlen		= sizeof(unsigned int),
355 		.mode		= 0644,
356 		.proc_handler	= sched_rt_handler,
357 	},
358 	{
359 		.procname	= "sched_rt_runtime_us",
360 		.data		= &sysctl_sched_rt_runtime,
361 		.maxlen		= sizeof(int),
362 		.mode		= 0644,
363 		.proc_handler	= sched_rt_handler,
364 	},
365 #ifdef CONFIG_SCHED_AUTOGROUP
366 	{
367 		.procname	= "sched_autogroup_enabled",
368 		.data		= &sysctl_sched_autogroup_enabled,
369 		.maxlen		= sizeof(unsigned int),
370 		.mode		= 0644,
371 		.proc_handler	= proc_dointvec_minmax,
372 		.extra1		= &zero,
373 		.extra2		= &one,
374 	},
375 #endif
376 #ifdef CONFIG_CFS_BANDWIDTH
377 	{
378 		.procname	= "sched_cfs_bandwidth_slice_us",
379 		.data		= &sysctl_sched_cfs_bandwidth_slice,
380 		.maxlen		= sizeof(unsigned int),
381 		.mode		= 0644,
382 		.proc_handler	= proc_dointvec_minmax,
383 		.extra1		= &one,
384 	},
385 #endif
386 #ifdef CONFIG_PROVE_LOCKING
387 	{
388 		.procname	= "prove_locking",
389 		.data		= &prove_locking,
390 		.maxlen		= sizeof(int),
391 		.mode		= 0644,
392 		.proc_handler	= proc_dointvec,
393 	},
394 #endif
395 #ifdef CONFIG_LOCK_STAT
396 	{
397 		.procname	= "lock_stat",
398 		.data		= &lock_stat,
399 		.maxlen		= sizeof(int),
400 		.mode		= 0644,
401 		.proc_handler	= proc_dointvec,
402 	},
403 #endif
404 	{
405 		.procname	= "panic",
406 		.data		= &panic_timeout,
407 		.maxlen		= sizeof(int),
408 		.mode		= 0644,
409 		.proc_handler	= proc_dointvec,
410 	},
411 	{
412 		.procname	= "core_uses_pid",
413 		.data		= &core_uses_pid,
414 		.maxlen		= sizeof(int),
415 		.mode		= 0644,
416 		.proc_handler	= proc_dointvec,
417 	},
418 	{
419 		.procname	= "core_pattern",
420 		.data		= core_pattern,
421 		.maxlen		= CORENAME_MAX_SIZE,
422 		.mode		= 0644,
423 		.proc_handler	= proc_dostring,
424 	},
425 	{
426 		.procname	= "core_pipe_limit",
427 		.data		= &core_pipe_limit,
428 		.maxlen		= sizeof(unsigned int),
429 		.mode		= 0644,
430 		.proc_handler	= proc_dointvec,
431 	},
432 #ifdef CONFIG_PROC_SYSCTL
433 	{
434 		.procname	= "tainted",
435 		.maxlen 	= sizeof(long),
436 		.mode		= 0644,
437 		.proc_handler	= proc_taint,
438 	},
439 #endif
440 #ifdef CONFIG_LATENCYTOP
441 	{
442 		.procname	= "latencytop",
443 		.data		= &latencytop_enabled,
444 		.maxlen		= sizeof(int),
445 		.mode		= 0644,
446 		.proc_handler	= proc_dointvec,
447 	},
448 #endif
449 #ifdef CONFIG_BLK_DEV_INITRD
450 	{
451 		.procname	= "real-root-dev",
452 		.data		= &real_root_dev,
453 		.maxlen		= sizeof(int),
454 		.mode		= 0644,
455 		.proc_handler	= proc_dointvec,
456 	},
457 #endif
458 	{
459 		.procname	= "print-fatal-signals",
460 		.data		= &print_fatal_signals,
461 		.maxlen		= sizeof(int),
462 		.mode		= 0644,
463 		.proc_handler	= proc_dointvec,
464 	},
465 #ifdef CONFIG_SPARC
466 	{
467 		.procname	= "reboot-cmd",
468 		.data		= reboot_command,
469 		.maxlen		= 256,
470 		.mode		= 0644,
471 		.proc_handler	= proc_dostring,
472 	},
473 	{
474 		.procname	= "stop-a",
475 		.data		= &stop_a_enabled,
476 		.maxlen		= sizeof (int),
477 		.mode		= 0644,
478 		.proc_handler	= proc_dointvec,
479 	},
480 	{
481 		.procname	= "scons-poweroff",
482 		.data		= &scons_pwroff,
483 		.maxlen		= sizeof (int),
484 		.mode		= 0644,
485 		.proc_handler	= proc_dointvec,
486 	},
487 #endif
488 #ifdef CONFIG_SPARC64
489 	{
490 		.procname	= "tsb-ratio",
491 		.data		= &sysctl_tsb_ratio,
492 		.maxlen		= sizeof (int),
493 		.mode		= 0644,
494 		.proc_handler	= proc_dointvec,
495 	},
496 #endif
497 #ifdef __hppa__
498 	{
499 		.procname	= "soft-power",
500 		.data		= &pwrsw_enabled,
501 		.maxlen		= sizeof (int),
502 	 	.mode		= 0644,
503 		.proc_handler	= proc_dointvec,
504 	},
505 	{
506 		.procname	= "unaligned-trap",
507 		.data		= &unaligned_enabled,
508 		.maxlen		= sizeof (int),
509 		.mode		= 0644,
510 		.proc_handler	= proc_dointvec,
511 	},
512 #endif
513 	{
514 		.procname	= "ctrl-alt-del",
515 		.data		= &C_A_D,
516 		.maxlen		= sizeof(int),
517 		.mode		= 0644,
518 		.proc_handler	= proc_dointvec,
519 	},
520 #ifdef CONFIG_FUNCTION_TRACER
521 	{
522 		.procname	= "ftrace_enabled",
523 		.data		= &ftrace_enabled,
524 		.maxlen		= sizeof(int),
525 		.mode		= 0644,
526 		.proc_handler	= ftrace_enable_sysctl,
527 	},
528 #endif
529 #ifdef CONFIG_STACK_TRACER
530 	{
531 		.procname	= "stack_tracer_enabled",
532 		.data		= &stack_tracer_enabled,
533 		.maxlen		= sizeof(int),
534 		.mode		= 0644,
535 		.proc_handler	= stack_trace_sysctl,
536 	},
537 #endif
538 #ifdef CONFIG_TRACING
539 	{
540 		.procname	= "ftrace_dump_on_oops",
541 		.data		= &ftrace_dump_on_oops,
542 		.maxlen		= sizeof(int),
543 		.mode		= 0644,
544 		.proc_handler	= proc_dointvec,
545 	},
546 #endif
547 #ifdef CONFIG_MODULES
548 	{
549 		.procname	= "modprobe",
550 		.data		= &modprobe_path,
551 		.maxlen		= KMOD_PATH_LEN,
552 		.mode		= 0644,
553 		.proc_handler	= proc_dostring,
554 	},
555 	{
556 		.procname	= "modules_disabled",
557 		.data		= &modules_disabled,
558 		.maxlen		= sizeof(int),
559 		.mode		= 0644,
560 		/* only handle a transition from default "0" to "1" */
561 		.proc_handler	= proc_dointvec_minmax,
562 		.extra1		= &one,
563 		.extra2		= &one,
564 	},
565 #endif
566 #ifdef CONFIG_HOTPLUG
567 	{
568 		.procname	= "hotplug",
569 		.data		= &uevent_helper,
570 		.maxlen		= UEVENT_HELPER_PATH_LEN,
571 		.mode		= 0644,
572 		.proc_handler	= proc_dostring,
573 	},
574 #endif
575 #ifdef CONFIG_CHR_DEV_SG
576 	{
577 		.procname	= "sg-big-buff",
578 		.data		= &sg_big_buff,
579 		.maxlen		= sizeof (int),
580 		.mode		= 0444,
581 		.proc_handler	= proc_dointvec,
582 	},
583 #endif
584 #ifdef CONFIG_BSD_PROCESS_ACCT
585 	{
586 		.procname	= "acct",
587 		.data		= &acct_parm,
588 		.maxlen		= 3*sizeof(int),
589 		.mode		= 0644,
590 		.proc_handler	= proc_dointvec,
591 	},
592 #endif
593 #ifdef CONFIG_MAGIC_SYSRQ
594 	{
595 		.procname	= "sysrq",
596 		.data		= &__sysrq_enabled,
597 		.maxlen		= sizeof (int),
598 		.mode		= 0644,
599 		.proc_handler	= sysrq_sysctl_handler,
600 	},
601 #endif
602 #ifdef CONFIG_PROC_SYSCTL
603 	{
604 		.procname	= "cad_pid",
605 		.data		= NULL,
606 		.maxlen		= sizeof (int),
607 		.mode		= 0600,
608 		.proc_handler	= proc_do_cad_pid,
609 	},
610 #endif
611 	{
612 		.procname	= "threads-max",
613 		.data		= &max_threads,
614 		.maxlen		= sizeof(int),
615 		.mode		= 0644,
616 		.proc_handler	= proc_dointvec,
617 	},
618 	{
619 		.procname	= "random",
620 		.mode		= 0555,
621 		.child		= random_table,
622 	},
623 	{
624 		.procname	= "usermodehelper",
625 		.mode		= 0555,
626 		.child		= usermodehelper_table,
627 	},
628 	{
629 		.procname	= "overflowuid",
630 		.data		= &overflowuid,
631 		.maxlen		= sizeof(int),
632 		.mode		= 0644,
633 		.proc_handler	= proc_dointvec_minmax,
634 		.extra1		= &minolduid,
635 		.extra2		= &maxolduid,
636 	},
637 	{
638 		.procname	= "overflowgid",
639 		.data		= &overflowgid,
640 		.maxlen		= sizeof(int),
641 		.mode		= 0644,
642 		.proc_handler	= proc_dointvec_minmax,
643 		.extra1		= &minolduid,
644 		.extra2		= &maxolduid,
645 	},
646 #ifdef CONFIG_S390
647 #ifdef CONFIG_MATHEMU
648 	{
649 		.procname	= "ieee_emulation_warnings",
650 		.data		= &sysctl_ieee_emulation_warnings,
651 		.maxlen		= sizeof(int),
652 		.mode		= 0644,
653 		.proc_handler	= proc_dointvec,
654 	},
655 #endif
656 	{
657 		.procname	= "userprocess_debug",
658 		.data		= &show_unhandled_signals,
659 		.maxlen		= sizeof(int),
660 		.mode		= 0644,
661 		.proc_handler	= proc_dointvec,
662 	},
663 #endif
664 	{
665 		.procname	= "pid_max",
666 		.data		= &pid_max,
667 		.maxlen		= sizeof (int),
668 		.mode		= 0644,
669 		.proc_handler	= proc_dointvec_minmax,
670 		.extra1		= &pid_max_min,
671 		.extra2		= &pid_max_max,
672 	},
673 	{
674 		.procname	= "panic_on_oops",
675 		.data		= &panic_on_oops,
676 		.maxlen		= sizeof(int),
677 		.mode		= 0644,
678 		.proc_handler	= proc_dointvec,
679 	},
680 #if defined CONFIG_PRINTK
681 	{
682 		.procname	= "printk",
683 		.data		= &console_loglevel,
684 		.maxlen		= 4*sizeof(int),
685 		.mode		= 0644,
686 		.proc_handler	= proc_dointvec,
687 	},
688 	{
689 		.procname	= "printk_ratelimit",
690 		.data		= &printk_ratelimit_state.interval,
691 		.maxlen		= sizeof(int),
692 		.mode		= 0644,
693 		.proc_handler	= proc_dointvec_jiffies,
694 	},
695 	{
696 		.procname	= "printk_ratelimit_burst",
697 		.data		= &printk_ratelimit_state.burst,
698 		.maxlen		= sizeof(int),
699 		.mode		= 0644,
700 		.proc_handler	= proc_dointvec,
701 	},
702 	{
703 		.procname	= "printk_delay",
704 		.data		= &printk_delay_msec,
705 		.maxlen		= sizeof(int),
706 		.mode		= 0644,
707 		.proc_handler	= proc_dointvec_minmax,
708 		.extra1		= &zero,
709 		.extra2		= &ten_thousand,
710 	},
711 	{
712 		.procname	= "dmesg_restrict",
713 		.data		= &dmesg_restrict,
714 		.maxlen		= sizeof(int),
715 		.mode		= 0644,
716 		.proc_handler	= proc_dointvec_minmax,
717 		.extra1		= &zero,
718 		.extra2		= &one,
719 	},
720 	{
721 		.procname	= "kptr_restrict",
722 		.data		= &kptr_restrict,
723 		.maxlen		= sizeof(int),
724 		.mode		= 0644,
725 		.proc_handler	= proc_dmesg_restrict,
726 		.extra1		= &zero,
727 		.extra2		= &two,
728 	},
729 #endif
730 	{
731 		.procname	= "ngroups_max",
732 		.data		= &ngroups_max,
733 		.maxlen		= sizeof (int),
734 		.mode		= 0444,
735 		.proc_handler	= proc_dointvec,
736 	},
737 	{
738 		.procname	= "cap_last_cap",
739 		.data		= (void *)&cap_last_cap,
740 		.maxlen		= sizeof(int),
741 		.mode		= 0444,
742 		.proc_handler	= proc_dointvec,
743 	},
744 #if defined(CONFIG_LOCKUP_DETECTOR)
745 	{
746 		.procname       = "watchdog",
747 		.data           = &watchdog_enabled,
748 		.maxlen         = sizeof (int),
749 		.mode           = 0644,
750 		.proc_handler   = proc_dowatchdog,
751 		.extra1		= &zero,
752 		.extra2		= &one,
753 	},
754 	{
755 		.procname	= "watchdog_thresh",
756 		.data		= &watchdog_thresh,
757 		.maxlen		= sizeof(int),
758 		.mode		= 0644,
759 		.proc_handler	= proc_dowatchdog,
760 		.extra1		= &neg_one,
761 		.extra2		= &sixty,
762 	},
763 	{
764 		.procname	= "softlockup_panic",
765 		.data		= &softlockup_panic,
766 		.maxlen		= sizeof(int),
767 		.mode		= 0644,
768 		.proc_handler	= proc_dointvec_minmax,
769 		.extra1		= &zero,
770 		.extra2		= &one,
771 	},
772 	{
773 		.procname       = "nmi_watchdog",
774 		.data           = &watchdog_enabled,
775 		.maxlen         = sizeof (int),
776 		.mode           = 0644,
777 		.proc_handler   = proc_dowatchdog,
778 		.extra1		= &zero,
779 		.extra2		= &one,
780 	},
781 #endif
782 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
783 	{
784 		.procname       = "unknown_nmi_panic",
785 		.data           = &unknown_nmi_panic,
786 		.maxlen         = sizeof (int),
787 		.mode           = 0644,
788 		.proc_handler   = proc_dointvec,
789 	},
790 #endif
791 #if defined(CONFIG_X86)
792 	{
793 		.procname	= "panic_on_unrecovered_nmi",
794 		.data		= &panic_on_unrecovered_nmi,
795 		.maxlen		= sizeof(int),
796 		.mode		= 0644,
797 		.proc_handler	= proc_dointvec,
798 	},
799 	{
800 		.procname	= "panic_on_io_nmi",
801 		.data		= &panic_on_io_nmi,
802 		.maxlen		= sizeof(int),
803 		.mode		= 0644,
804 		.proc_handler	= proc_dointvec,
805 	},
806 	{
807 		.procname	= "bootloader_type",
808 		.data		= &bootloader_type,
809 		.maxlen		= sizeof (int),
810 		.mode		= 0444,
811 		.proc_handler	= proc_dointvec,
812 	},
813 	{
814 		.procname	= "bootloader_version",
815 		.data		= &bootloader_version,
816 		.maxlen		= sizeof (int),
817 		.mode		= 0444,
818 		.proc_handler	= proc_dointvec,
819 	},
820 	{
821 		.procname	= "kstack_depth_to_print",
822 		.data		= &kstack_depth_to_print,
823 		.maxlen		= sizeof(int),
824 		.mode		= 0644,
825 		.proc_handler	= proc_dointvec,
826 	},
827 	{
828 		.procname	= "io_delay_type",
829 		.data		= &io_delay_type,
830 		.maxlen		= sizeof(int),
831 		.mode		= 0644,
832 		.proc_handler	= proc_dointvec,
833 	},
834 #endif
835 #if defined(CONFIG_MMU)
836 	{
837 		.procname	= "randomize_va_space",
838 		.data		= &randomize_va_space,
839 		.maxlen		= sizeof(int),
840 		.mode		= 0644,
841 		.proc_handler	= proc_dointvec,
842 	},
843 #endif
844 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
845 	{
846 		.procname	= "spin_retry",
847 		.data		= &spin_retry,
848 		.maxlen		= sizeof (int),
849 		.mode		= 0644,
850 		.proc_handler	= proc_dointvec,
851 	},
852 #endif
853 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
854 	{
855 		.procname	= "acpi_video_flags",
856 		.data		= &acpi_realmode_flags,
857 		.maxlen		= sizeof (unsigned long),
858 		.mode		= 0644,
859 		.proc_handler	= proc_doulongvec_minmax,
860 	},
861 #endif
862 #ifdef CONFIG_IA64
863 	{
864 		.procname	= "ignore-unaligned-usertrap",
865 		.data		= &no_unaligned_warning,
866 		.maxlen		= sizeof (int),
867 	 	.mode		= 0644,
868 		.proc_handler	= proc_dointvec,
869 	},
870 	{
871 		.procname	= "unaligned-dump-stack",
872 		.data		= &unaligned_dump_stack,
873 		.maxlen		= sizeof (int),
874 		.mode		= 0644,
875 		.proc_handler	= proc_dointvec,
876 	},
877 #endif
878 #ifdef CONFIG_DETECT_HUNG_TASK
879 	{
880 		.procname	= "hung_task_panic",
881 		.data		= &sysctl_hung_task_panic,
882 		.maxlen		= sizeof(int),
883 		.mode		= 0644,
884 		.proc_handler	= proc_dointvec_minmax,
885 		.extra1		= &zero,
886 		.extra2		= &one,
887 	},
888 	{
889 		.procname	= "hung_task_check_count",
890 		.data		= &sysctl_hung_task_check_count,
891 		.maxlen		= sizeof(unsigned long),
892 		.mode		= 0644,
893 		.proc_handler	= proc_doulongvec_minmax,
894 	},
895 	{
896 		.procname	= "hung_task_timeout_secs",
897 		.data		= &sysctl_hung_task_timeout_secs,
898 		.maxlen		= sizeof(unsigned long),
899 		.mode		= 0644,
900 		.proc_handler	= proc_dohung_task_timeout_secs,
901 	},
902 	{
903 		.procname	= "hung_task_warnings",
904 		.data		= &sysctl_hung_task_warnings,
905 		.maxlen		= sizeof(unsigned long),
906 		.mode		= 0644,
907 		.proc_handler	= proc_doulongvec_minmax,
908 	},
909 #endif
910 #ifdef CONFIG_COMPAT
911 	{
912 		.procname	= "compat-log",
913 		.data		= &compat_log,
914 		.maxlen		= sizeof (int),
915 	 	.mode		= 0644,
916 		.proc_handler	= proc_dointvec,
917 	},
918 #endif
919 #ifdef CONFIG_RT_MUTEXES
920 	{
921 		.procname	= "max_lock_depth",
922 		.data		= &max_lock_depth,
923 		.maxlen		= sizeof(int),
924 		.mode		= 0644,
925 		.proc_handler	= proc_dointvec,
926 	},
927 #endif
928 	{
929 		.procname	= "poweroff_cmd",
930 		.data		= &poweroff_cmd,
931 		.maxlen		= POWEROFF_CMD_PATH_LEN,
932 		.mode		= 0644,
933 		.proc_handler	= proc_dostring,
934 	},
935 #ifdef CONFIG_KEYS
936 	{
937 		.procname	= "keys",
938 		.mode		= 0555,
939 		.child		= key_sysctls,
940 	},
941 #endif
942 #ifdef CONFIG_RCU_TORTURE_TEST
943 	{
944 		.procname       = "rcutorture_runnable",
945 		.data           = &rcutorture_runnable,
946 		.maxlen         = sizeof(int),
947 		.mode           = 0644,
948 		.proc_handler	= proc_dointvec,
949 	},
950 #endif
951 #ifdef CONFIG_PERF_EVENTS
952 	/*
953 	 * User-space scripts rely on the existence of this file
954 	 * as a feature check for perf_events being enabled.
955 	 *
956 	 * So it's an ABI, do not remove!
957 	 */
958 	{
959 		.procname	= "perf_event_paranoid",
960 		.data		= &sysctl_perf_event_paranoid,
961 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
962 		.mode		= 0644,
963 		.proc_handler	= proc_dointvec,
964 	},
965 	{
966 		.procname	= "perf_event_mlock_kb",
967 		.data		= &sysctl_perf_event_mlock,
968 		.maxlen		= sizeof(sysctl_perf_event_mlock),
969 		.mode		= 0644,
970 		.proc_handler	= proc_dointvec,
971 	},
972 	{
973 		.procname	= "perf_event_max_sample_rate",
974 		.data		= &sysctl_perf_event_sample_rate,
975 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
976 		.mode		= 0644,
977 		.proc_handler	= perf_proc_update_handler,
978 	},
979 #endif
980 #ifdef CONFIG_KMEMCHECK
981 	{
982 		.procname	= "kmemcheck",
983 		.data		= &kmemcheck_enabled,
984 		.maxlen		= sizeof(int),
985 		.mode		= 0644,
986 		.proc_handler	= proc_dointvec,
987 	},
988 #endif
989 #ifdef CONFIG_BLOCK
990 	{
991 		.procname	= "blk_iopoll",
992 		.data		= &blk_iopoll_enabled,
993 		.maxlen		= sizeof(int),
994 		.mode		= 0644,
995 		.proc_handler	= proc_dointvec,
996 	},
997 #endif
998 	{ }
999 };
1000 
1001 static struct ctl_table vm_table[] = {
1002 	{
1003 		.procname	= "overcommit_memory",
1004 		.data		= &sysctl_overcommit_memory,
1005 		.maxlen		= sizeof(sysctl_overcommit_memory),
1006 		.mode		= 0644,
1007 		.proc_handler	= proc_dointvec_minmax,
1008 		.extra1		= &zero,
1009 		.extra2		= &two,
1010 	},
1011 	{
1012 		.procname	= "panic_on_oom",
1013 		.data		= &sysctl_panic_on_oom,
1014 		.maxlen		= sizeof(sysctl_panic_on_oom),
1015 		.mode		= 0644,
1016 		.proc_handler	= proc_dointvec_minmax,
1017 		.extra1		= &zero,
1018 		.extra2		= &two,
1019 	},
1020 	{
1021 		.procname	= "oom_kill_allocating_task",
1022 		.data		= &sysctl_oom_kill_allocating_task,
1023 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1024 		.mode		= 0644,
1025 		.proc_handler	= proc_dointvec,
1026 	},
1027 	{
1028 		.procname	= "oom_dump_tasks",
1029 		.data		= &sysctl_oom_dump_tasks,
1030 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1031 		.mode		= 0644,
1032 		.proc_handler	= proc_dointvec,
1033 	},
1034 	{
1035 		.procname	= "overcommit_ratio",
1036 		.data		= &sysctl_overcommit_ratio,
1037 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1038 		.mode		= 0644,
1039 		.proc_handler	= proc_dointvec,
1040 	},
1041 	{
1042 		.procname	= "page-cluster",
1043 		.data		= &page_cluster,
1044 		.maxlen		= sizeof(int),
1045 		.mode		= 0644,
1046 		.proc_handler	= proc_dointvec_minmax,
1047 		.extra1		= &zero,
1048 	},
1049 	{
1050 		.procname	= "dirty_background_ratio",
1051 		.data		= &dirty_background_ratio,
1052 		.maxlen		= sizeof(dirty_background_ratio),
1053 		.mode		= 0644,
1054 		.proc_handler	= dirty_background_ratio_handler,
1055 		.extra1		= &zero,
1056 		.extra2		= &one_hundred,
1057 	},
1058 	{
1059 		.procname	= "dirty_background_bytes",
1060 		.data		= &dirty_background_bytes,
1061 		.maxlen		= sizeof(dirty_background_bytes),
1062 		.mode		= 0644,
1063 		.proc_handler	= dirty_background_bytes_handler,
1064 		.extra1		= &one_ul,
1065 	},
1066 	{
1067 		.procname	= "dirty_ratio",
1068 		.data		= &vm_dirty_ratio,
1069 		.maxlen		= sizeof(vm_dirty_ratio),
1070 		.mode		= 0644,
1071 		.proc_handler	= dirty_ratio_handler,
1072 		.extra1		= &zero,
1073 		.extra2		= &one_hundred,
1074 	},
1075 	{
1076 		.procname	= "dirty_bytes",
1077 		.data		= &vm_dirty_bytes,
1078 		.maxlen		= sizeof(vm_dirty_bytes),
1079 		.mode		= 0644,
1080 		.proc_handler	= dirty_bytes_handler,
1081 		.extra1		= &dirty_bytes_min,
1082 	},
1083 	{
1084 		.procname	= "dirty_writeback_centisecs",
1085 		.data		= &dirty_writeback_interval,
1086 		.maxlen		= sizeof(dirty_writeback_interval),
1087 		.mode		= 0644,
1088 		.proc_handler	= dirty_writeback_centisecs_handler,
1089 	},
1090 	{
1091 		.procname	= "dirty_expire_centisecs",
1092 		.data		= &dirty_expire_interval,
1093 		.maxlen		= sizeof(dirty_expire_interval),
1094 		.mode		= 0644,
1095 		.proc_handler	= proc_dointvec_minmax,
1096 		.extra1		= &zero,
1097 	},
1098 	{
1099 		.procname	= "nr_pdflush_threads",
1100 		.data		= &nr_pdflush_threads,
1101 		.maxlen		= sizeof nr_pdflush_threads,
1102 		.mode		= 0444 /* read-only*/,
1103 		.proc_handler	= proc_dointvec,
1104 	},
1105 	{
1106 		.procname	= "swappiness",
1107 		.data		= &vm_swappiness,
1108 		.maxlen		= sizeof(vm_swappiness),
1109 		.mode		= 0644,
1110 		.proc_handler	= proc_dointvec_minmax,
1111 		.extra1		= &zero,
1112 		.extra2		= &one_hundred,
1113 	},
1114 #ifdef CONFIG_HUGETLB_PAGE
1115 	{
1116 		.procname	= "nr_hugepages",
1117 		.data		= NULL,
1118 		.maxlen		= sizeof(unsigned long),
1119 		.mode		= 0644,
1120 		.proc_handler	= hugetlb_sysctl_handler,
1121 		.extra1		= (void *)&hugetlb_zero,
1122 		.extra2		= (void *)&hugetlb_infinity,
1123 	},
1124 #ifdef CONFIG_NUMA
1125 	{
1126 		.procname       = "nr_hugepages_mempolicy",
1127 		.data           = NULL,
1128 		.maxlen         = sizeof(unsigned long),
1129 		.mode           = 0644,
1130 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1131 		.extra1		= (void *)&hugetlb_zero,
1132 		.extra2		= (void *)&hugetlb_infinity,
1133 	},
1134 #endif
1135 	 {
1136 		.procname	= "hugetlb_shm_group",
1137 		.data		= &sysctl_hugetlb_shm_group,
1138 		.maxlen		= sizeof(gid_t),
1139 		.mode		= 0644,
1140 		.proc_handler	= proc_dointvec,
1141 	 },
1142 	 {
1143 		.procname	= "hugepages_treat_as_movable",
1144 		.data		= &hugepages_treat_as_movable,
1145 		.maxlen		= sizeof(int),
1146 		.mode		= 0644,
1147 		.proc_handler	= hugetlb_treat_movable_handler,
1148 	},
1149 	{
1150 		.procname	= "nr_overcommit_hugepages",
1151 		.data		= NULL,
1152 		.maxlen		= sizeof(unsigned long),
1153 		.mode		= 0644,
1154 		.proc_handler	= hugetlb_overcommit_handler,
1155 		.extra1		= (void *)&hugetlb_zero,
1156 		.extra2		= (void *)&hugetlb_infinity,
1157 	},
1158 #endif
1159 	{
1160 		.procname	= "lowmem_reserve_ratio",
1161 		.data		= &sysctl_lowmem_reserve_ratio,
1162 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1163 		.mode		= 0644,
1164 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1165 	},
1166 	{
1167 		.procname	= "drop_caches",
1168 		.data		= &sysctl_drop_caches,
1169 		.maxlen		= sizeof(int),
1170 		.mode		= 0644,
1171 		.proc_handler	= drop_caches_sysctl_handler,
1172 		.extra1		= &one,
1173 		.extra2		= &three,
1174 	},
1175 #ifdef CONFIG_COMPACTION
1176 	{
1177 		.procname	= "compact_memory",
1178 		.data		= &sysctl_compact_memory,
1179 		.maxlen		= sizeof(int),
1180 		.mode		= 0200,
1181 		.proc_handler	= sysctl_compaction_handler,
1182 	},
1183 	{
1184 		.procname	= "extfrag_threshold",
1185 		.data		= &sysctl_extfrag_threshold,
1186 		.maxlen		= sizeof(int),
1187 		.mode		= 0644,
1188 		.proc_handler	= sysctl_extfrag_handler,
1189 		.extra1		= &min_extfrag_threshold,
1190 		.extra2		= &max_extfrag_threshold,
1191 	},
1192 
1193 #endif /* CONFIG_COMPACTION */
1194 	{
1195 		.procname	= "min_free_kbytes",
1196 		.data		= &min_free_kbytes,
1197 		.maxlen		= sizeof(min_free_kbytes),
1198 		.mode		= 0644,
1199 		.proc_handler	= min_free_kbytes_sysctl_handler,
1200 		.extra1		= &zero,
1201 	},
1202 	{
1203 		.procname	= "percpu_pagelist_fraction",
1204 		.data		= &percpu_pagelist_fraction,
1205 		.maxlen		= sizeof(percpu_pagelist_fraction),
1206 		.mode		= 0644,
1207 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1208 		.extra1		= &min_percpu_pagelist_fract,
1209 	},
1210 #ifdef CONFIG_MMU
1211 	{
1212 		.procname	= "max_map_count",
1213 		.data		= &sysctl_max_map_count,
1214 		.maxlen		= sizeof(sysctl_max_map_count),
1215 		.mode		= 0644,
1216 		.proc_handler	= proc_dointvec_minmax,
1217 		.extra1		= &zero,
1218 	},
1219 #else
1220 	{
1221 		.procname	= "nr_trim_pages",
1222 		.data		= &sysctl_nr_trim_pages,
1223 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1224 		.mode		= 0644,
1225 		.proc_handler	= proc_dointvec_minmax,
1226 		.extra1		= &zero,
1227 	},
1228 #endif
1229 	{
1230 		.procname	= "laptop_mode",
1231 		.data		= &laptop_mode,
1232 		.maxlen		= sizeof(laptop_mode),
1233 		.mode		= 0644,
1234 		.proc_handler	= proc_dointvec_jiffies,
1235 	},
1236 	{
1237 		.procname	= "block_dump",
1238 		.data		= &block_dump,
1239 		.maxlen		= sizeof(block_dump),
1240 		.mode		= 0644,
1241 		.proc_handler	= proc_dointvec,
1242 		.extra1		= &zero,
1243 	},
1244 	{
1245 		.procname	= "vfs_cache_pressure",
1246 		.data		= &sysctl_vfs_cache_pressure,
1247 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1248 		.mode		= 0644,
1249 		.proc_handler	= proc_dointvec,
1250 		.extra1		= &zero,
1251 	},
1252 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1253 	{
1254 		.procname	= "legacy_va_layout",
1255 		.data		= &sysctl_legacy_va_layout,
1256 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1257 		.mode		= 0644,
1258 		.proc_handler	= proc_dointvec,
1259 		.extra1		= &zero,
1260 	},
1261 #endif
1262 #ifdef CONFIG_NUMA
1263 	{
1264 		.procname	= "zone_reclaim_mode",
1265 		.data		= &zone_reclaim_mode,
1266 		.maxlen		= sizeof(zone_reclaim_mode),
1267 		.mode		= 0644,
1268 		.proc_handler	= proc_dointvec,
1269 		.extra1		= &zero,
1270 	},
1271 	{
1272 		.procname	= "min_unmapped_ratio",
1273 		.data		= &sysctl_min_unmapped_ratio,
1274 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1275 		.mode		= 0644,
1276 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1277 		.extra1		= &zero,
1278 		.extra2		= &one_hundred,
1279 	},
1280 	{
1281 		.procname	= "min_slab_ratio",
1282 		.data		= &sysctl_min_slab_ratio,
1283 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1284 		.mode		= 0644,
1285 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1286 		.extra1		= &zero,
1287 		.extra2		= &one_hundred,
1288 	},
1289 #endif
1290 #ifdef CONFIG_SMP
1291 	{
1292 		.procname	= "stat_interval",
1293 		.data		= &sysctl_stat_interval,
1294 		.maxlen		= sizeof(sysctl_stat_interval),
1295 		.mode		= 0644,
1296 		.proc_handler	= proc_dointvec_jiffies,
1297 	},
1298 #endif
1299 #ifdef CONFIG_MMU
1300 	{
1301 		.procname	= "mmap_min_addr",
1302 		.data		= &dac_mmap_min_addr,
1303 		.maxlen		= sizeof(unsigned long),
1304 		.mode		= 0644,
1305 		.proc_handler	= mmap_min_addr_handler,
1306 	},
1307 #endif
1308 #ifdef CONFIG_NUMA
1309 	{
1310 		.procname	= "numa_zonelist_order",
1311 		.data		= &numa_zonelist_order,
1312 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1313 		.mode		= 0644,
1314 		.proc_handler	= numa_zonelist_order_handler,
1315 	},
1316 #endif
1317 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1318    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1319 	{
1320 		.procname	= "vdso_enabled",
1321 		.data		= &vdso_enabled,
1322 		.maxlen		= sizeof(vdso_enabled),
1323 		.mode		= 0644,
1324 		.proc_handler	= proc_dointvec,
1325 		.extra1		= &zero,
1326 	},
1327 #endif
1328 #ifdef CONFIG_HIGHMEM
1329 	{
1330 		.procname	= "highmem_is_dirtyable",
1331 		.data		= &vm_highmem_is_dirtyable,
1332 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1333 		.mode		= 0644,
1334 		.proc_handler	= proc_dointvec_minmax,
1335 		.extra1		= &zero,
1336 		.extra2		= &one,
1337 	},
1338 #endif
1339 	{
1340 		.procname	= "scan_unevictable_pages",
1341 		.data		= &scan_unevictable_pages,
1342 		.maxlen		= sizeof(scan_unevictable_pages),
1343 		.mode		= 0644,
1344 		.proc_handler	= scan_unevictable_handler,
1345 	},
1346 #ifdef CONFIG_MEMORY_FAILURE
1347 	{
1348 		.procname	= "memory_failure_early_kill",
1349 		.data		= &sysctl_memory_failure_early_kill,
1350 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1351 		.mode		= 0644,
1352 		.proc_handler	= proc_dointvec_minmax,
1353 		.extra1		= &zero,
1354 		.extra2		= &one,
1355 	},
1356 	{
1357 		.procname	= "memory_failure_recovery",
1358 		.data		= &sysctl_memory_failure_recovery,
1359 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1360 		.mode		= 0644,
1361 		.proc_handler	= proc_dointvec_minmax,
1362 		.extra1		= &zero,
1363 		.extra2		= &one,
1364 	},
1365 #endif
1366 	{ }
1367 };
1368 
1369 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1370 static struct ctl_table binfmt_misc_table[] = {
1371 	{ }
1372 };
1373 #endif
1374 
1375 static struct ctl_table fs_table[] = {
1376 	{
1377 		.procname	= "inode-nr",
1378 		.data		= &inodes_stat,
1379 		.maxlen		= 2*sizeof(int),
1380 		.mode		= 0444,
1381 		.proc_handler	= proc_nr_inodes,
1382 	},
1383 	{
1384 		.procname	= "inode-state",
1385 		.data		= &inodes_stat,
1386 		.maxlen		= 7*sizeof(int),
1387 		.mode		= 0444,
1388 		.proc_handler	= proc_nr_inodes,
1389 	},
1390 	{
1391 		.procname	= "file-nr",
1392 		.data		= &files_stat,
1393 		.maxlen		= sizeof(files_stat),
1394 		.mode		= 0444,
1395 		.proc_handler	= proc_nr_files,
1396 	},
1397 	{
1398 		.procname	= "file-max",
1399 		.data		= &files_stat.max_files,
1400 		.maxlen		= sizeof(files_stat.max_files),
1401 		.mode		= 0644,
1402 		.proc_handler	= proc_doulongvec_minmax,
1403 	},
1404 	{
1405 		.procname	= "nr_open",
1406 		.data		= &sysctl_nr_open,
1407 		.maxlen		= sizeof(int),
1408 		.mode		= 0644,
1409 		.proc_handler	= proc_dointvec_minmax,
1410 		.extra1		= &sysctl_nr_open_min,
1411 		.extra2		= &sysctl_nr_open_max,
1412 	},
1413 	{
1414 		.procname	= "dentry-state",
1415 		.data		= &dentry_stat,
1416 		.maxlen		= 6*sizeof(int),
1417 		.mode		= 0444,
1418 		.proc_handler	= proc_nr_dentry,
1419 	},
1420 	{
1421 		.procname	= "overflowuid",
1422 		.data		= &fs_overflowuid,
1423 		.maxlen		= sizeof(int),
1424 		.mode		= 0644,
1425 		.proc_handler	= proc_dointvec_minmax,
1426 		.extra1		= &minolduid,
1427 		.extra2		= &maxolduid,
1428 	},
1429 	{
1430 		.procname	= "overflowgid",
1431 		.data		= &fs_overflowgid,
1432 		.maxlen		= sizeof(int),
1433 		.mode		= 0644,
1434 		.proc_handler	= proc_dointvec_minmax,
1435 		.extra1		= &minolduid,
1436 		.extra2		= &maxolduid,
1437 	},
1438 #ifdef CONFIG_FILE_LOCKING
1439 	{
1440 		.procname	= "leases-enable",
1441 		.data		= &leases_enable,
1442 		.maxlen		= sizeof(int),
1443 		.mode		= 0644,
1444 		.proc_handler	= proc_dointvec,
1445 	},
1446 #endif
1447 #ifdef CONFIG_DNOTIFY
1448 	{
1449 		.procname	= "dir-notify-enable",
1450 		.data		= &dir_notify_enable,
1451 		.maxlen		= sizeof(int),
1452 		.mode		= 0644,
1453 		.proc_handler	= proc_dointvec,
1454 	},
1455 #endif
1456 #ifdef CONFIG_MMU
1457 #ifdef CONFIG_FILE_LOCKING
1458 	{
1459 		.procname	= "lease-break-time",
1460 		.data		= &lease_break_time,
1461 		.maxlen		= sizeof(int),
1462 		.mode		= 0644,
1463 		.proc_handler	= proc_dointvec,
1464 	},
1465 #endif
1466 #ifdef CONFIG_AIO
1467 	{
1468 		.procname	= "aio-nr",
1469 		.data		= &aio_nr,
1470 		.maxlen		= sizeof(aio_nr),
1471 		.mode		= 0444,
1472 		.proc_handler	= proc_doulongvec_minmax,
1473 	},
1474 	{
1475 		.procname	= "aio-max-nr",
1476 		.data		= &aio_max_nr,
1477 		.maxlen		= sizeof(aio_max_nr),
1478 		.mode		= 0644,
1479 		.proc_handler	= proc_doulongvec_minmax,
1480 	},
1481 #endif /* CONFIG_AIO */
1482 #ifdef CONFIG_INOTIFY_USER
1483 	{
1484 		.procname	= "inotify",
1485 		.mode		= 0555,
1486 		.child		= inotify_table,
1487 	},
1488 #endif
1489 #ifdef CONFIG_EPOLL
1490 	{
1491 		.procname	= "epoll",
1492 		.mode		= 0555,
1493 		.child		= epoll_table,
1494 	},
1495 #endif
1496 #endif
1497 	{
1498 		.procname	= "suid_dumpable",
1499 		.data		= &suid_dumpable,
1500 		.maxlen		= sizeof(int),
1501 		.mode		= 0644,
1502 		.proc_handler	= proc_dointvec_minmax,
1503 		.extra1		= &zero,
1504 		.extra2		= &two,
1505 	},
1506 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1507 	{
1508 		.procname	= "binfmt_misc",
1509 		.mode		= 0555,
1510 		.child		= binfmt_misc_table,
1511 	},
1512 #endif
1513 	{
1514 		.procname	= "pipe-max-size",
1515 		.data		= &pipe_max_size,
1516 		.maxlen		= sizeof(int),
1517 		.mode		= 0644,
1518 		.proc_handler	= &pipe_proc_fn,
1519 		.extra1		= &pipe_min_size,
1520 	},
1521 	{ }
1522 };
1523 
1524 static struct ctl_table debug_table[] = {
1525 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1526     defined(CONFIG_S390) || defined(CONFIG_TILE)
1527 	{
1528 		.procname	= "exception-trace",
1529 		.data		= &show_unhandled_signals,
1530 		.maxlen		= sizeof(int),
1531 		.mode		= 0644,
1532 		.proc_handler	= proc_dointvec
1533 	},
1534 #endif
1535 #if defined(CONFIG_OPTPROBES)
1536 	{
1537 		.procname	= "kprobes-optimization",
1538 		.data		= &sysctl_kprobes_optimization,
1539 		.maxlen		= sizeof(int),
1540 		.mode		= 0644,
1541 		.proc_handler	= proc_kprobes_optimization_handler,
1542 		.extra1		= &zero,
1543 		.extra2		= &one,
1544 	},
1545 #endif
1546 	{ }
1547 };
1548 
1549 static struct ctl_table dev_table[] = {
1550 	{ }
1551 };
1552 
1553 static DEFINE_SPINLOCK(sysctl_lock);
1554 
1555 /* called under sysctl_lock */
1556 static int use_table(struct ctl_table_header *p)
1557 {
1558 	if (unlikely(p->unregistering))
1559 		return 0;
1560 	p->used++;
1561 	return 1;
1562 }
1563 
1564 /* called under sysctl_lock */
1565 static void unuse_table(struct ctl_table_header *p)
1566 {
1567 	if (!--p->used)
1568 		if (unlikely(p->unregistering))
1569 			complete(p->unregistering);
1570 }
1571 
1572 /* called under sysctl_lock, will reacquire if has to wait */
1573 static void start_unregistering(struct ctl_table_header *p)
1574 {
1575 	/*
1576 	 * if p->used is 0, nobody will ever touch that entry again;
1577 	 * we'll eliminate all paths to it before dropping sysctl_lock
1578 	 */
1579 	if (unlikely(p->used)) {
1580 		struct completion wait;
1581 		init_completion(&wait);
1582 		p->unregistering = &wait;
1583 		spin_unlock(&sysctl_lock);
1584 		wait_for_completion(&wait);
1585 		spin_lock(&sysctl_lock);
1586 	} else {
1587 		/* anything non-NULL; we'll never dereference it */
1588 		p->unregistering = ERR_PTR(-EINVAL);
1589 	}
1590 	/*
1591 	 * do not remove from the list until nobody holds it; walking the
1592 	 * list in do_sysctl() relies on that.
1593 	 */
1594 	list_del_init(&p->ctl_entry);
1595 }
1596 
1597 void sysctl_head_get(struct ctl_table_header *head)
1598 {
1599 	spin_lock(&sysctl_lock);
1600 	head->count++;
1601 	spin_unlock(&sysctl_lock);
1602 }
1603 
1604 void sysctl_head_put(struct ctl_table_header *head)
1605 {
1606 	spin_lock(&sysctl_lock);
1607 	if (!--head->count)
1608 		kfree_rcu(head, rcu);
1609 	spin_unlock(&sysctl_lock);
1610 }
1611 
1612 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1613 {
1614 	if (!head)
1615 		BUG();
1616 	spin_lock(&sysctl_lock);
1617 	if (!use_table(head))
1618 		head = ERR_PTR(-ENOENT);
1619 	spin_unlock(&sysctl_lock);
1620 	return head;
1621 }
1622 
1623 void sysctl_head_finish(struct ctl_table_header *head)
1624 {
1625 	if (!head)
1626 		return;
1627 	spin_lock(&sysctl_lock);
1628 	unuse_table(head);
1629 	spin_unlock(&sysctl_lock);
1630 }
1631 
1632 static struct ctl_table_set *
1633 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1634 {
1635 	struct ctl_table_set *set = &root->default_set;
1636 	if (root->lookup)
1637 		set = root->lookup(root, namespaces);
1638 	return set;
1639 }
1640 
1641 static struct list_head *
1642 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1643 {
1644 	struct ctl_table_set *set = lookup_header_set(root, namespaces);
1645 	return &set->list;
1646 }
1647 
1648 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1649 					    struct ctl_table_header *prev)
1650 {
1651 	struct ctl_table_root *root;
1652 	struct list_head *header_list;
1653 	struct ctl_table_header *head;
1654 	struct list_head *tmp;
1655 
1656 	spin_lock(&sysctl_lock);
1657 	if (prev) {
1658 		head = prev;
1659 		tmp = &prev->ctl_entry;
1660 		unuse_table(prev);
1661 		goto next;
1662 	}
1663 	tmp = &root_table_header.ctl_entry;
1664 	for (;;) {
1665 		head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1666 
1667 		if (!use_table(head))
1668 			goto next;
1669 		spin_unlock(&sysctl_lock);
1670 		return head;
1671 	next:
1672 		root = head->root;
1673 		tmp = tmp->next;
1674 		header_list = lookup_header_list(root, namespaces);
1675 		if (tmp != header_list)
1676 			continue;
1677 
1678 		do {
1679 			root = list_entry(root->root_list.next,
1680 					struct ctl_table_root, root_list);
1681 			if (root == &sysctl_table_root)
1682 				goto out;
1683 			header_list = lookup_header_list(root, namespaces);
1684 		} while (list_empty(header_list));
1685 		tmp = header_list->next;
1686 	}
1687 out:
1688 	spin_unlock(&sysctl_lock);
1689 	return NULL;
1690 }
1691 
1692 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1693 {
1694 	return __sysctl_head_next(current->nsproxy, prev);
1695 }
1696 
1697 void register_sysctl_root(struct ctl_table_root *root)
1698 {
1699 	spin_lock(&sysctl_lock);
1700 	list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1701 	spin_unlock(&sysctl_lock);
1702 }
1703 
1704 /*
1705  * sysctl_perm does NOT grant the superuser all rights automatically, because
1706  * some sysctl variables are readonly even to root.
1707  */
1708 
1709 static int test_perm(int mode, int op)
1710 {
1711 	if (!current_euid())
1712 		mode >>= 6;
1713 	else if (in_egroup_p(0))
1714 		mode >>= 3;
1715 	if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1716 		return 0;
1717 	return -EACCES;
1718 }
1719 
1720 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1721 {
1722 	int mode;
1723 
1724 	if (root->permissions)
1725 		mode = root->permissions(root, current->nsproxy, table);
1726 	else
1727 		mode = table->mode;
1728 
1729 	return test_perm(mode, op);
1730 }
1731 
1732 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1733 {
1734 	for (; table->procname; table++) {
1735 		table->parent = parent;
1736 		if (table->child)
1737 			sysctl_set_parent(table, table->child);
1738 	}
1739 }
1740 
1741 static __init int sysctl_init(void)
1742 {
1743 	sysctl_set_parent(NULL, root_table);
1744 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1745 	sysctl_check_table(current->nsproxy, root_table);
1746 #endif
1747 	return 0;
1748 }
1749 
1750 core_initcall(sysctl_init);
1751 
1752 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1753 				      struct ctl_table *table)
1754 {
1755 	struct ctl_table *p;
1756 	const char *s = branch->procname;
1757 
1758 	/* branch should have named subdirectory as its first element */
1759 	if (!s || !branch->child)
1760 		return NULL;
1761 
1762 	/* ... and nothing else */
1763 	if (branch[1].procname)
1764 		return NULL;
1765 
1766 	/* table should contain subdirectory with the same name */
1767 	for (p = table; p->procname; p++) {
1768 		if (!p->child)
1769 			continue;
1770 		if (p->procname && strcmp(p->procname, s) == 0)
1771 			return p;
1772 	}
1773 	return NULL;
1774 }
1775 
1776 /* see if attaching q to p would be an improvement */
1777 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1778 {
1779 	struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1780 	struct ctl_table *next;
1781 	int is_better = 0;
1782 	int not_in_parent = !p->attached_by;
1783 
1784 	while ((next = is_branch_in(by, to)) != NULL) {
1785 		if (by == q->attached_by)
1786 			is_better = 1;
1787 		if (to == p->attached_by)
1788 			not_in_parent = 1;
1789 		by = by->child;
1790 		to = next->child;
1791 	}
1792 
1793 	if (is_better && not_in_parent) {
1794 		q->attached_by = by;
1795 		q->attached_to = to;
1796 		q->parent = p;
1797 	}
1798 }
1799 
1800 /**
1801  * __register_sysctl_paths - register a sysctl hierarchy
1802  * @root: List of sysctl headers to register on
1803  * @namespaces: Data to compute which lists of sysctl entries are visible
1804  * @path: The path to the directory the sysctl table is in.
1805  * @table: the top-level table structure
1806  *
1807  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1808  * array. A completely 0 filled entry terminates the table.
1809  *
1810  * The members of the &struct ctl_table structure are used as follows:
1811  *
1812  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1813  *            enter a sysctl file
1814  *
1815  * data - a pointer to data for use by proc_handler
1816  *
1817  * maxlen - the maximum size in bytes of the data
1818  *
1819  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1820  *
1821  * child - a pointer to the child sysctl table if this entry is a directory, or
1822  *         %NULL.
1823  *
1824  * proc_handler - the text handler routine (described below)
1825  *
1826  * de - for internal use by the sysctl routines
1827  *
1828  * extra1, extra2 - extra pointers usable by the proc handler routines
1829  *
1830  * Leaf nodes in the sysctl tree will be represented by a single file
1831  * under /proc; non-leaf nodes will be represented by directories.
1832  *
1833  * sysctl(2) can automatically manage read and write requests through
1834  * the sysctl table.  The data and maxlen fields of the ctl_table
1835  * struct enable minimal validation of the values being written to be
1836  * performed, and the mode field allows minimal authentication.
1837  *
1838  * There must be a proc_handler routine for any terminal nodes
1839  * mirrored under /proc/sys (non-terminals are handled by a built-in
1840  * directory handler).  Several default handlers are available to
1841  * cover common cases -
1842  *
1843  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1844  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1845  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1846  *
1847  * It is the handler's job to read the input buffer from user memory
1848  * and process it. The handler should return 0 on success.
1849  *
1850  * This routine returns %NULL on a failure to register, and a pointer
1851  * to the table header on success.
1852  */
1853 struct ctl_table_header *__register_sysctl_paths(
1854 	struct ctl_table_root *root,
1855 	struct nsproxy *namespaces,
1856 	const struct ctl_path *path, struct ctl_table *table)
1857 {
1858 	struct ctl_table_header *header;
1859 	struct ctl_table *new, **prevp;
1860 	unsigned int n, npath;
1861 	struct ctl_table_set *set;
1862 
1863 	/* Count the path components */
1864 	for (npath = 0; path[npath].procname; ++npath)
1865 		;
1866 
1867 	/*
1868 	 * For each path component, allocate a 2-element ctl_table array.
1869 	 * The first array element will be filled with the sysctl entry
1870 	 * for this, the second will be the sentinel (procname == 0).
1871 	 *
1872 	 * We allocate everything in one go so that we don't have to
1873 	 * worry about freeing additional memory in unregister_sysctl_table.
1874 	 */
1875 	header = kzalloc(sizeof(struct ctl_table_header) +
1876 			 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1877 	if (!header)
1878 		return NULL;
1879 
1880 	new = (struct ctl_table *) (header + 1);
1881 
1882 	/* Now connect the dots */
1883 	prevp = &header->ctl_table;
1884 	for (n = 0; n < npath; ++n, ++path) {
1885 		/* Copy the procname */
1886 		new->procname = path->procname;
1887 		new->mode     = 0555;
1888 
1889 		*prevp = new;
1890 		prevp = &new->child;
1891 
1892 		new += 2;
1893 	}
1894 	*prevp = table;
1895 	header->ctl_table_arg = table;
1896 
1897 	INIT_LIST_HEAD(&header->ctl_entry);
1898 	header->used = 0;
1899 	header->unregistering = NULL;
1900 	header->root = root;
1901 	sysctl_set_parent(NULL, header->ctl_table);
1902 	header->count = 1;
1903 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1904 	if (sysctl_check_table(namespaces, header->ctl_table)) {
1905 		kfree(header);
1906 		return NULL;
1907 	}
1908 #endif
1909 	spin_lock(&sysctl_lock);
1910 	header->set = lookup_header_set(root, namespaces);
1911 	header->attached_by = header->ctl_table;
1912 	header->attached_to = root_table;
1913 	header->parent = &root_table_header;
1914 	for (set = header->set; set; set = set->parent) {
1915 		struct ctl_table_header *p;
1916 		list_for_each_entry(p, &set->list, ctl_entry) {
1917 			if (p->unregistering)
1918 				continue;
1919 			try_attach(p, header);
1920 		}
1921 	}
1922 	header->parent->count++;
1923 	list_add_tail(&header->ctl_entry, &header->set->list);
1924 	spin_unlock(&sysctl_lock);
1925 
1926 	return header;
1927 }
1928 
1929 /**
1930  * register_sysctl_table_path - register a sysctl table hierarchy
1931  * @path: The path to the directory the sysctl table is in.
1932  * @table: the top-level table structure
1933  *
1934  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1935  * array. A completely 0 filled entry terminates the table.
1936  *
1937  * See __register_sysctl_paths for more details.
1938  */
1939 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1940 						struct ctl_table *table)
1941 {
1942 	return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1943 					path, table);
1944 }
1945 
1946 /**
1947  * register_sysctl_table - register a sysctl table hierarchy
1948  * @table: the top-level table structure
1949  *
1950  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1951  * array. A completely 0 filled entry terminates the table.
1952  *
1953  * See register_sysctl_paths for more details.
1954  */
1955 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1956 {
1957 	static const struct ctl_path null_path[] = { {} };
1958 
1959 	return register_sysctl_paths(null_path, table);
1960 }
1961 
1962 /**
1963  * unregister_sysctl_table - unregister a sysctl table hierarchy
1964  * @header: the header returned from register_sysctl_table
1965  *
1966  * Unregisters the sysctl table and all children. proc entries may not
1967  * actually be removed until they are no longer used by anyone.
1968  */
1969 void unregister_sysctl_table(struct ctl_table_header * header)
1970 {
1971 	might_sleep();
1972 
1973 	if (header == NULL)
1974 		return;
1975 
1976 	spin_lock(&sysctl_lock);
1977 	start_unregistering(header);
1978 	if (!--header->parent->count) {
1979 		WARN_ON(1);
1980 		kfree_rcu(header->parent, rcu);
1981 	}
1982 	if (!--header->count)
1983 		kfree_rcu(header, rcu);
1984 	spin_unlock(&sysctl_lock);
1985 }
1986 
1987 int sysctl_is_seen(struct ctl_table_header *p)
1988 {
1989 	struct ctl_table_set *set = p->set;
1990 	int res;
1991 	spin_lock(&sysctl_lock);
1992 	if (p->unregistering)
1993 		res = 0;
1994 	else if (!set->is_seen)
1995 		res = 1;
1996 	else
1997 		res = set->is_seen(set);
1998 	spin_unlock(&sysctl_lock);
1999 	return res;
2000 }
2001 
2002 void setup_sysctl_set(struct ctl_table_set *p,
2003 	struct ctl_table_set *parent,
2004 	int (*is_seen)(struct ctl_table_set *))
2005 {
2006 	INIT_LIST_HEAD(&p->list);
2007 	p->parent = parent ? parent : &sysctl_table_root.default_set;
2008 	p->is_seen = is_seen;
2009 }
2010 
2011 #else /* !CONFIG_SYSCTL */
2012 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2013 {
2014 	return NULL;
2015 }
2016 
2017 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2018 						    struct ctl_table *table)
2019 {
2020 	return NULL;
2021 }
2022 
2023 void unregister_sysctl_table(struct ctl_table_header * table)
2024 {
2025 }
2026 
2027 void setup_sysctl_set(struct ctl_table_set *p,
2028 	struct ctl_table_set *parent,
2029 	int (*is_seen)(struct ctl_table_set *))
2030 {
2031 }
2032 
2033 void sysctl_head_put(struct ctl_table_header *head)
2034 {
2035 }
2036 
2037 #endif /* CONFIG_SYSCTL */
2038 
2039 /*
2040  * /proc/sys support
2041  */
2042 
2043 #ifdef CONFIG_PROC_SYSCTL
2044 
2045 static int _proc_do_string(void* data, int maxlen, int write,
2046 			   void __user *buffer,
2047 			   size_t *lenp, loff_t *ppos)
2048 {
2049 	size_t len;
2050 	char __user *p;
2051 	char c;
2052 
2053 	if (!data || !maxlen || !*lenp) {
2054 		*lenp = 0;
2055 		return 0;
2056 	}
2057 
2058 	if (write) {
2059 		len = 0;
2060 		p = buffer;
2061 		while (len < *lenp) {
2062 			if (get_user(c, p++))
2063 				return -EFAULT;
2064 			if (c == 0 || c == '\n')
2065 				break;
2066 			len++;
2067 		}
2068 		if (len >= maxlen)
2069 			len = maxlen-1;
2070 		if(copy_from_user(data, buffer, len))
2071 			return -EFAULT;
2072 		((char *) data)[len] = 0;
2073 		*ppos += *lenp;
2074 	} else {
2075 		len = strlen(data);
2076 		if (len > maxlen)
2077 			len = maxlen;
2078 
2079 		if (*ppos > len) {
2080 			*lenp = 0;
2081 			return 0;
2082 		}
2083 
2084 		data += *ppos;
2085 		len  -= *ppos;
2086 
2087 		if (len > *lenp)
2088 			len = *lenp;
2089 		if (len)
2090 			if(copy_to_user(buffer, data, len))
2091 				return -EFAULT;
2092 		if (len < *lenp) {
2093 			if(put_user('\n', ((char __user *) buffer) + len))
2094 				return -EFAULT;
2095 			len++;
2096 		}
2097 		*lenp = len;
2098 		*ppos += len;
2099 	}
2100 	return 0;
2101 }
2102 
2103 /**
2104  * proc_dostring - read a string sysctl
2105  * @table: the sysctl table
2106  * @write: %TRUE if this is a write to the sysctl file
2107  * @buffer: the user buffer
2108  * @lenp: the size of the user buffer
2109  * @ppos: file position
2110  *
2111  * Reads/writes a string from/to the user buffer. If the kernel
2112  * buffer provided is not large enough to hold the string, the
2113  * string is truncated. The copied string is %NULL-terminated.
2114  * If the string is being read by the user process, it is copied
2115  * and a newline '\n' is added. It is truncated if the buffer is
2116  * not large enough.
2117  *
2118  * Returns 0 on success.
2119  */
2120 int proc_dostring(struct ctl_table *table, int write,
2121 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2122 {
2123 	return _proc_do_string(table->data, table->maxlen, write,
2124 			       buffer, lenp, ppos);
2125 }
2126 
2127 static size_t proc_skip_spaces(char **buf)
2128 {
2129 	size_t ret;
2130 	char *tmp = skip_spaces(*buf);
2131 	ret = tmp - *buf;
2132 	*buf = tmp;
2133 	return ret;
2134 }
2135 
2136 static void proc_skip_char(char **buf, size_t *size, const char v)
2137 {
2138 	while (*size) {
2139 		if (**buf != v)
2140 			break;
2141 		(*size)--;
2142 		(*buf)++;
2143 	}
2144 }
2145 
2146 #define TMPBUFLEN 22
2147 /**
2148  * proc_get_long - reads an ASCII formatted integer from a user buffer
2149  *
2150  * @buf: a kernel buffer
2151  * @size: size of the kernel buffer
2152  * @val: this is where the number will be stored
2153  * @neg: set to %TRUE if number is negative
2154  * @perm_tr: a vector which contains the allowed trailers
2155  * @perm_tr_len: size of the perm_tr vector
2156  * @tr: pointer to store the trailer character
2157  *
2158  * In case of success %0 is returned and @buf and @size are updated with
2159  * the amount of bytes read. If @tr is non-NULL and a trailing
2160  * character exists (size is non-zero after returning from this
2161  * function), @tr is updated with the trailing character.
2162  */
2163 static int proc_get_long(char **buf, size_t *size,
2164 			  unsigned long *val, bool *neg,
2165 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2166 {
2167 	int len;
2168 	char *p, tmp[TMPBUFLEN];
2169 
2170 	if (!*size)
2171 		return -EINVAL;
2172 
2173 	len = *size;
2174 	if (len > TMPBUFLEN - 1)
2175 		len = TMPBUFLEN - 1;
2176 
2177 	memcpy(tmp, *buf, len);
2178 
2179 	tmp[len] = 0;
2180 	p = tmp;
2181 	if (*p == '-' && *size > 1) {
2182 		*neg = true;
2183 		p++;
2184 	} else
2185 		*neg = false;
2186 	if (!isdigit(*p))
2187 		return -EINVAL;
2188 
2189 	*val = simple_strtoul(p, &p, 0);
2190 
2191 	len = p - tmp;
2192 
2193 	/* We don't know if the next char is whitespace thus we may accept
2194 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2195 	 * (e.g. 123...1). So lets not allow such large numbers. */
2196 	if (len == TMPBUFLEN - 1)
2197 		return -EINVAL;
2198 
2199 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2200 		return -EINVAL;
2201 
2202 	if (tr && (len < *size))
2203 		*tr = *p;
2204 
2205 	*buf += len;
2206 	*size -= len;
2207 
2208 	return 0;
2209 }
2210 
2211 /**
2212  * proc_put_long - converts an integer to a decimal ASCII formatted string
2213  *
2214  * @buf: the user buffer
2215  * @size: the size of the user buffer
2216  * @val: the integer to be converted
2217  * @neg: sign of the number, %TRUE for negative
2218  *
2219  * In case of success %0 is returned and @buf and @size are updated with
2220  * the amount of bytes written.
2221  */
2222 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2223 			  bool neg)
2224 {
2225 	int len;
2226 	char tmp[TMPBUFLEN], *p = tmp;
2227 
2228 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2229 	len = strlen(tmp);
2230 	if (len > *size)
2231 		len = *size;
2232 	if (copy_to_user(*buf, tmp, len))
2233 		return -EFAULT;
2234 	*size -= len;
2235 	*buf += len;
2236 	return 0;
2237 }
2238 #undef TMPBUFLEN
2239 
2240 static int proc_put_char(void __user **buf, size_t *size, char c)
2241 {
2242 	if (*size) {
2243 		char __user **buffer = (char __user **)buf;
2244 		if (put_user(c, *buffer))
2245 			return -EFAULT;
2246 		(*size)--, (*buffer)++;
2247 		*buf = *buffer;
2248 	}
2249 	return 0;
2250 }
2251 
2252 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2253 				 int *valp,
2254 				 int write, void *data)
2255 {
2256 	if (write) {
2257 		*valp = *negp ? -*lvalp : *lvalp;
2258 	} else {
2259 		int val = *valp;
2260 		if (val < 0) {
2261 			*negp = true;
2262 			*lvalp = (unsigned long)-val;
2263 		} else {
2264 			*negp = false;
2265 			*lvalp = (unsigned long)val;
2266 		}
2267 	}
2268 	return 0;
2269 }
2270 
2271 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2272 
2273 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2274 		  int write, void __user *buffer,
2275 		  size_t *lenp, loff_t *ppos,
2276 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2277 			      int write, void *data),
2278 		  void *data)
2279 {
2280 	int *i, vleft, first = 1, err = 0;
2281 	unsigned long page = 0;
2282 	size_t left;
2283 	char *kbuf;
2284 
2285 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2286 		*lenp = 0;
2287 		return 0;
2288 	}
2289 
2290 	i = (int *) tbl_data;
2291 	vleft = table->maxlen / sizeof(*i);
2292 	left = *lenp;
2293 
2294 	if (!conv)
2295 		conv = do_proc_dointvec_conv;
2296 
2297 	if (write) {
2298 		if (left > PAGE_SIZE - 1)
2299 			left = PAGE_SIZE - 1;
2300 		page = __get_free_page(GFP_TEMPORARY);
2301 		kbuf = (char *) page;
2302 		if (!kbuf)
2303 			return -ENOMEM;
2304 		if (copy_from_user(kbuf, buffer, left)) {
2305 			err = -EFAULT;
2306 			goto free;
2307 		}
2308 		kbuf[left] = 0;
2309 	}
2310 
2311 	for (; left && vleft--; i++, first=0) {
2312 		unsigned long lval;
2313 		bool neg;
2314 
2315 		if (write) {
2316 			left -= proc_skip_spaces(&kbuf);
2317 
2318 			if (!left)
2319 				break;
2320 			err = proc_get_long(&kbuf, &left, &lval, &neg,
2321 					     proc_wspace_sep,
2322 					     sizeof(proc_wspace_sep), NULL);
2323 			if (err)
2324 				break;
2325 			if (conv(&neg, &lval, i, 1, data)) {
2326 				err = -EINVAL;
2327 				break;
2328 			}
2329 		} else {
2330 			if (conv(&neg, &lval, i, 0, data)) {
2331 				err = -EINVAL;
2332 				break;
2333 			}
2334 			if (!first)
2335 				err = proc_put_char(&buffer, &left, '\t');
2336 			if (err)
2337 				break;
2338 			err = proc_put_long(&buffer, &left, lval, neg);
2339 			if (err)
2340 				break;
2341 		}
2342 	}
2343 
2344 	if (!write && !first && left && !err)
2345 		err = proc_put_char(&buffer, &left, '\n');
2346 	if (write && !err && left)
2347 		left -= proc_skip_spaces(&kbuf);
2348 free:
2349 	if (write) {
2350 		free_page(page);
2351 		if (first)
2352 			return err ? : -EINVAL;
2353 	}
2354 	*lenp -= left;
2355 	*ppos += *lenp;
2356 	return err;
2357 }
2358 
2359 static int do_proc_dointvec(struct ctl_table *table, int write,
2360 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2361 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2362 			      int write, void *data),
2363 		  void *data)
2364 {
2365 	return __do_proc_dointvec(table->data, table, write,
2366 			buffer, lenp, ppos, conv, data);
2367 }
2368 
2369 /**
2370  * proc_dointvec - read a vector of integers
2371  * @table: the sysctl table
2372  * @write: %TRUE if this is a write to the sysctl file
2373  * @buffer: the user buffer
2374  * @lenp: the size of the user buffer
2375  * @ppos: file position
2376  *
2377  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2378  * values from/to the user buffer, treated as an ASCII string.
2379  *
2380  * Returns 0 on success.
2381  */
2382 int proc_dointvec(struct ctl_table *table, int write,
2383 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2384 {
2385     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2386 		    	    NULL,NULL);
2387 }
2388 
2389 /*
2390  * Taint values can only be increased
2391  * This means we can safely use a temporary.
2392  */
2393 static int proc_taint(struct ctl_table *table, int write,
2394 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2395 {
2396 	struct ctl_table t;
2397 	unsigned long tmptaint = get_taint();
2398 	int err;
2399 
2400 	if (write && !capable(CAP_SYS_ADMIN))
2401 		return -EPERM;
2402 
2403 	t = *table;
2404 	t.data = &tmptaint;
2405 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2406 	if (err < 0)
2407 		return err;
2408 
2409 	if (write) {
2410 		/*
2411 		 * Poor man's atomic or. Not worth adding a primitive
2412 		 * to everyone's atomic.h for this
2413 		 */
2414 		int i;
2415 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2416 			if ((tmptaint >> i) & 1)
2417 				add_taint(i);
2418 		}
2419 	}
2420 
2421 	return err;
2422 }
2423 
2424 #ifdef CONFIG_PRINTK
2425 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2426 				void __user *buffer, size_t *lenp, loff_t *ppos)
2427 {
2428 	if (write && !capable(CAP_SYS_ADMIN))
2429 		return -EPERM;
2430 
2431 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2432 }
2433 #endif
2434 
2435 struct do_proc_dointvec_minmax_conv_param {
2436 	int *min;
2437 	int *max;
2438 };
2439 
2440 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2441 					int *valp,
2442 					int write, void *data)
2443 {
2444 	struct do_proc_dointvec_minmax_conv_param *param = data;
2445 	if (write) {
2446 		int val = *negp ? -*lvalp : *lvalp;
2447 		if ((param->min && *param->min > val) ||
2448 		    (param->max && *param->max < val))
2449 			return -EINVAL;
2450 		*valp = val;
2451 	} else {
2452 		int val = *valp;
2453 		if (val < 0) {
2454 			*negp = true;
2455 			*lvalp = (unsigned long)-val;
2456 		} else {
2457 			*negp = false;
2458 			*lvalp = (unsigned long)val;
2459 		}
2460 	}
2461 	return 0;
2462 }
2463 
2464 /**
2465  * proc_dointvec_minmax - read a vector of integers with min/max values
2466  * @table: the sysctl table
2467  * @write: %TRUE if this is a write to the sysctl file
2468  * @buffer: the user buffer
2469  * @lenp: the size of the user buffer
2470  * @ppos: file position
2471  *
2472  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2473  * values from/to the user buffer, treated as an ASCII string.
2474  *
2475  * This routine will ensure the values are within the range specified by
2476  * table->extra1 (min) and table->extra2 (max).
2477  *
2478  * Returns 0 on success.
2479  */
2480 int proc_dointvec_minmax(struct ctl_table *table, int write,
2481 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2482 {
2483 	struct do_proc_dointvec_minmax_conv_param param = {
2484 		.min = (int *) table->extra1,
2485 		.max = (int *) table->extra2,
2486 	};
2487 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2488 				do_proc_dointvec_minmax_conv, &param);
2489 }
2490 
2491 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2492 				     void __user *buffer,
2493 				     size_t *lenp, loff_t *ppos,
2494 				     unsigned long convmul,
2495 				     unsigned long convdiv)
2496 {
2497 	unsigned long *i, *min, *max;
2498 	int vleft, first = 1, err = 0;
2499 	unsigned long page = 0;
2500 	size_t left;
2501 	char *kbuf;
2502 
2503 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2504 		*lenp = 0;
2505 		return 0;
2506 	}
2507 
2508 	i = (unsigned long *) data;
2509 	min = (unsigned long *) table->extra1;
2510 	max = (unsigned long *) table->extra2;
2511 	vleft = table->maxlen / sizeof(unsigned long);
2512 	left = *lenp;
2513 
2514 	if (write) {
2515 		if (left > PAGE_SIZE - 1)
2516 			left = PAGE_SIZE - 1;
2517 		page = __get_free_page(GFP_TEMPORARY);
2518 		kbuf = (char *) page;
2519 		if (!kbuf)
2520 			return -ENOMEM;
2521 		if (copy_from_user(kbuf, buffer, left)) {
2522 			err = -EFAULT;
2523 			goto free;
2524 		}
2525 		kbuf[left] = 0;
2526 	}
2527 
2528 	for (; left && vleft--; i++, first = 0) {
2529 		unsigned long val;
2530 
2531 		if (write) {
2532 			bool neg;
2533 
2534 			left -= proc_skip_spaces(&kbuf);
2535 
2536 			err = proc_get_long(&kbuf, &left, &val, &neg,
2537 					     proc_wspace_sep,
2538 					     sizeof(proc_wspace_sep), NULL);
2539 			if (err)
2540 				break;
2541 			if (neg)
2542 				continue;
2543 			if ((min && val < *min) || (max && val > *max))
2544 				continue;
2545 			*i = val;
2546 		} else {
2547 			val = convdiv * (*i) / convmul;
2548 			if (!first)
2549 				err = proc_put_char(&buffer, &left, '\t');
2550 			err = proc_put_long(&buffer, &left, val, false);
2551 			if (err)
2552 				break;
2553 		}
2554 	}
2555 
2556 	if (!write && !first && left && !err)
2557 		err = proc_put_char(&buffer, &left, '\n');
2558 	if (write && !err)
2559 		left -= proc_skip_spaces(&kbuf);
2560 free:
2561 	if (write) {
2562 		free_page(page);
2563 		if (first)
2564 			return err ? : -EINVAL;
2565 	}
2566 	*lenp -= left;
2567 	*ppos += *lenp;
2568 	return err;
2569 }
2570 
2571 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2572 				     void __user *buffer,
2573 				     size_t *lenp, loff_t *ppos,
2574 				     unsigned long convmul,
2575 				     unsigned long convdiv)
2576 {
2577 	return __do_proc_doulongvec_minmax(table->data, table, write,
2578 			buffer, lenp, ppos, convmul, convdiv);
2579 }
2580 
2581 /**
2582  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2583  * @table: the sysctl table
2584  * @write: %TRUE if this is a write to the sysctl file
2585  * @buffer: the user buffer
2586  * @lenp: the size of the user buffer
2587  * @ppos: file position
2588  *
2589  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2590  * values from/to the user buffer, treated as an ASCII string.
2591  *
2592  * This routine will ensure the values are within the range specified by
2593  * table->extra1 (min) and table->extra2 (max).
2594  *
2595  * Returns 0 on success.
2596  */
2597 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2598 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2599 {
2600     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2601 }
2602 
2603 /**
2604  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2605  * @table: the sysctl table
2606  * @write: %TRUE if this is a write to the sysctl file
2607  * @buffer: the user buffer
2608  * @lenp: the size of the user buffer
2609  * @ppos: file position
2610  *
2611  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2612  * values from/to the user buffer, treated as an ASCII string. The values
2613  * are treated as milliseconds, and converted to jiffies when they are stored.
2614  *
2615  * This routine will ensure the values are within the range specified by
2616  * table->extra1 (min) and table->extra2 (max).
2617  *
2618  * Returns 0 on success.
2619  */
2620 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2621 				      void __user *buffer,
2622 				      size_t *lenp, loff_t *ppos)
2623 {
2624     return do_proc_doulongvec_minmax(table, write, buffer,
2625 				     lenp, ppos, HZ, 1000l);
2626 }
2627 
2628 
2629 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2630 					 int *valp,
2631 					 int write, void *data)
2632 {
2633 	if (write) {
2634 		if (*lvalp > LONG_MAX / HZ)
2635 			return 1;
2636 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2637 	} else {
2638 		int val = *valp;
2639 		unsigned long lval;
2640 		if (val < 0) {
2641 			*negp = true;
2642 			lval = (unsigned long)-val;
2643 		} else {
2644 			*negp = false;
2645 			lval = (unsigned long)val;
2646 		}
2647 		*lvalp = lval / HZ;
2648 	}
2649 	return 0;
2650 }
2651 
2652 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2653 						int *valp,
2654 						int write, void *data)
2655 {
2656 	if (write) {
2657 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2658 			return 1;
2659 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2660 	} else {
2661 		int val = *valp;
2662 		unsigned long lval;
2663 		if (val < 0) {
2664 			*negp = true;
2665 			lval = (unsigned long)-val;
2666 		} else {
2667 			*negp = false;
2668 			lval = (unsigned long)val;
2669 		}
2670 		*lvalp = jiffies_to_clock_t(lval);
2671 	}
2672 	return 0;
2673 }
2674 
2675 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2676 					    int *valp,
2677 					    int write, void *data)
2678 {
2679 	if (write) {
2680 		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2681 	} else {
2682 		int val = *valp;
2683 		unsigned long lval;
2684 		if (val < 0) {
2685 			*negp = true;
2686 			lval = (unsigned long)-val;
2687 		} else {
2688 			*negp = false;
2689 			lval = (unsigned long)val;
2690 		}
2691 		*lvalp = jiffies_to_msecs(lval);
2692 	}
2693 	return 0;
2694 }
2695 
2696 /**
2697  * proc_dointvec_jiffies - read a vector of integers as seconds
2698  * @table: the sysctl table
2699  * @write: %TRUE if this is a write to the sysctl file
2700  * @buffer: the user buffer
2701  * @lenp: the size of the user buffer
2702  * @ppos: file position
2703  *
2704  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2705  * values from/to the user buffer, treated as an ASCII string.
2706  * The values read are assumed to be in seconds, and are converted into
2707  * jiffies.
2708  *
2709  * Returns 0 on success.
2710  */
2711 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2712 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2713 {
2714     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2715 		    	    do_proc_dointvec_jiffies_conv,NULL);
2716 }
2717 
2718 /**
2719  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2720  * @table: the sysctl table
2721  * @write: %TRUE if this is a write to the sysctl file
2722  * @buffer: the user buffer
2723  * @lenp: the size of the user buffer
2724  * @ppos: pointer to the file position
2725  *
2726  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2727  * values from/to the user buffer, treated as an ASCII string.
2728  * The values read are assumed to be in 1/USER_HZ seconds, and
2729  * are converted into jiffies.
2730  *
2731  * Returns 0 on success.
2732  */
2733 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2734 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2735 {
2736     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2737 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2738 }
2739 
2740 /**
2741  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2742  * @table: the sysctl table
2743  * @write: %TRUE if this is a write to the sysctl file
2744  * @buffer: the user buffer
2745  * @lenp: the size of the user buffer
2746  * @ppos: file position
2747  * @ppos: the current position in the file
2748  *
2749  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2750  * values from/to the user buffer, treated as an ASCII string.
2751  * The values read are assumed to be in 1/1000 seconds, and
2752  * are converted into jiffies.
2753  *
2754  * Returns 0 on success.
2755  */
2756 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2757 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2758 {
2759 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2760 				do_proc_dointvec_ms_jiffies_conv, NULL);
2761 }
2762 
2763 static int proc_do_cad_pid(struct ctl_table *table, int write,
2764 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2765 {
2766 	struct pid *new_pid;
2767 	pid_t tmp;
2768 	int r;
2769 
2770 	tmp = pid_vnr(cad_pid);
2771 
2772 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2773 			       lenp, ppos, NULL, NULL);
2774 	if (r || !write)
2775 		return r;
2776 
2777 	new_pid = find_get_pid(tmp);
2778 	if (!new_pid)
2779 		return -ESRCH;
2780 
2781 	put_pid(xchg(&cad_pid, new_pid));
2782 	return 0;
2783 }
2784 
2785 /**
2786  * proc_do_large_bitmap - read/write from/to a large bitmap
2787  * @table: the sysctl table
2788  * @write: %TRUE if this is a write to the sysctl file
2789  * @buffer: the user buffer
2790  * @lenp: the size of the user buffer
2791  * @ppos: file position
2792  *
2793  * The bitmap is stored at table->data and the bitmap length (in bits)
2794  * in table->maxlen.
2795  *
2796  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2797  * large bitmaps may be represented in a compact manner. Writing into
2798  * the file will clear the bitmap then update it with the given input.
2799  *
2800  * Returns 0 on success.
2801  */
2802 int proc_do_large_bitmap(struct ctl_table *table, int write,
2803 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2804 {
2805 	int err = 0;
2806 	bool first = 1;
2807 	size_t left = *lenp;
2808 	unsigned long bitmap_len = table->maxlen;
2809 	unsigned long *bitmap = (unsigned long *) table->data;
2810 	unsigned long *tmp_bitmap = NULL;
2811 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2812 
2813 	if (!bitmap_len || !left || (*ppos && !write)) {
2814 		*lenp = 0;
2815 		return 0;
2816 	}
2817 
2818 	if (write) {
2819 		unsigned long page = 0;
2820 		char *kbuf;
2821 
2822 		if (left > PAGE_SIZE - 1)
2823 			left = PAGE_SIZE - 1;
2824 
2825 		page = __get_free_page(GFP_TEMPORARY);
2826 		kbuf = (char *) page;
2827 		if (!kbuf)
2828 			return -ENOMEM;
2829 		if (copy_from_user(kbuf, buffer, left)) {
2830 			free_page(page);
2831 			return -EFAULT;
2832                 }
2833 		kbuf[left] = 0;
2834 
2835 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2836 				     GFP_KERNEL);
2837 		if (!tmp_bitmap) {
2838 			free_page(page);
2839 			return -ENOMEM;
2840 		}
2841 		proc_skip_char(&kbuf, &left, '\n');
2842 		while (!err && left) {
2843 			unsigned long val_a, val_b;
2844 			bool neg;
2845 
2846 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2847 					     sizeof(tr_a), &c);
2848 			if (err)
2849 				break;
2850 			if (val_a >= bitmap_len || neg) {
2851 				err = -EINVAL;
2852 				break;
2853 			}
2854 
2855 			val_b = val_a;
2856 			if (left) {
2857 				kbuf++;
2858 				left--;
2859 			}
2860 
2861 			if (c == '-') {
2862 				err = proc_get_long(&kbuf, &left, &val_b,
2863 						     &neg, tr_b, sizeof(tr_b),
2864 						     &c);
2865 				if (err)
2866 					break;
2867 				if (val_b >= bitmap_len || neg ||
2868 				    val_a > val_b) {
2869 					err = -EINVAL;
2870 					break;
2871 				}
2872 				if (left) {
2873 					kbuf++;
2874 					left--;
2875 				}
2876 			}
2877 
2878 			while (val_a <= val_b)
2879 				set_bit(val_a++, tmp_bitmap);
2880 
2881 			first = 0;
2882 			proc_skip_char(&kbuf, &left, '\n');
2883 		}
2884 		free_page(page);
2885 	} else {
2886 		unsigned long bit_a, bit_b = 0;
2887 
2888 		while (left) {
2889 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2890 			if (bit_a >= bitmap_len)
2891 				break;
2892 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2893 						   bit_a + 1) - 1;
2894 
2895 			if (!first) {
2896 				err = proc_put_char(&buffer, &left, ',');
2897 				if (err)
2898 					break;
2899 			}
2900 			err = proc_put_long(&buffer, &left, bit_a, false);
2901 			if (err)
2902 				break;
2903 			if (bit_a != bit_b) {
2904 				err = proc_put_char(&buffer, &left, '-');
2905 				if (err)
2906 					break;
2907 				err = proc_put_long(&buffer, &left, bit_b, false);
2908 				if (err)
2909 					break;
2910 			}
2911 
2912 			first = 0; bit_b++;
2913 		}
2914 		if (!err)
2915 			err = proc_put_char(&buffer, &left, '\n');
2916 	}
2917 
2918 	if (!err) {
2919 		if (write) {
2920 			if (*ppos)
2921 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2922 			else
2923 				memcpy(bitmap, tmp_bitmap,
2924 					BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2925 		}
2926 		kfree(tmp_bitmap);
2927 		*lenp -= left;
2928 		*ppos += *lenp;
2929 		return 0;
2930 	} else {
2931 		kfree(tmp_bitmap);
2932 		return err;
2933 	}
2934 }
2935 
2936 #else /* CONFIG_PROC_SYSCTL */
2937 
2938 int proc_dostring(struct ctl_table *table, int write,
2939 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2940 {
2941 	return -ENOSYS;
2942 }
2943 
2944 int proc_dointvec(struct ctl_table *table, int write,
2945 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2946 {
2947 	return -ENOSYS;
2948 }
2949 
2950 int proc_dointvec_minmax(struct ctl_table *table, int write,
2951 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2952 {
2953 	return -ENOSYS;
2954 }
2955 
2956 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2957 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2958 {
2959 	return -ENOSYS;
2960 }
2961 
2962 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2963 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2964 {
2965 	return -ENOSYS;
2966 }
2967 
2968 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2969 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2970 {
2971 	return -ENOSYS;
2972 }
2973 
2974 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2975 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2976 {
2977 	return -ENOSYS;
2978 }
2979 
2980 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2981 				      void __user *buffer,
2982 				      size_t *lenp, loff_t *ppos)
2983 {
2984     return -ENOSYS;
2985 }
2986 
2987 
2988 #endif /* CONFIG_PROC_SYSCTL */
2989 
2990 /*
2991  * No sense putting this after each symbol definition, twice,
2992  * exception granted :-)
2993  */
2994 EXPORT_SYMBOL(proc_dointvec);
2995 EXPORT_SYMBOL(proc_dointvec_jiffies);
2996 EXPORT_SYMBOL(proc_dointvec_minmax);
2997 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2998 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2999 EXPORT_SYMBOL(proc_dostring);
3000 EXPORT_SYMBOL(proc_doulongvec_minmax);
3001 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3002 EXPORT_SYMBOL(register_sysctl_table);
3003 EXPORT_SYMBOL(register_sysctl_paths);
3004 EXPORT_SYMBOL(unregister_sysctl_table);
3005