xref: /linux/kernel/sysctl.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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 #ifdef CONFIG_DEBUG_STACKOVERFLOW
807 	{
808 		.procname	= "panic_on_stackoverflow",
809 		.data		= &sysctl_panic_on_stackoverflow,
810 		.maxlen		= sizeof(int),
811 		.mode		= 0644,
812 		.proc_handler	= proc_dointvec,
813 	},
814 #endif
815 	{
816 		.procname	= "bootloader_type",
817 		.data		= &bootloader_type,
818 		.maxlen		= sizeof (int),
819 		.mode		= 0444,
820 		.proc_handler	= proc_dointvec,
821 	},
822 	{
823 		.procname	= "bootloader_version",
824 		.data		= &bootloader_version,
825 		.maxlen		= sizeof (int),
826 		.mode		= 0444,
827 		.proc_handler	= proc_dointvec,
828 	},
829 	{
830 		.procname	= "kstack_depth_to_print",
831 		.data		= &kstack_depth_to_print,
832 		.maxlen		= sizeof(int),
833 		.mode		= 0644,
834 		.proc_handler	= proc_dointvec,
835 	},
836 	{
837 		.procname	= "io_delay_type",
838 		.data		= &io_delay_type,
839 		.maxlen		= sizeof(int),
840 		.mode		= 0644,
841 		.proc_handler	= proc_dointvec,
842 	},
843 #endif
844 #if defined(CONFIG_MMU)
845 	{
846 		.procname	= "randomize_va_space",
847 		.data		= &randomize_va_space,
848 		.maxlen		= sizeof(int),
849 		.mode		= 0644,
850 		.proc_handler	= proc_dointvec,
851 	},
852 #endif
853 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
854 	{
855 		.procname	= "spin_retry",
856 		.data		= &spin_retry,
857 		.maxlen		= sizeof (int),
858 		.mode		= 0644,
859 		.proc_handler	= proc_dointvec,
860 	},
861 #endif
862 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
863 	{
864 		.procname	= "acpi_video_flags",
865 		.data		= &acpi_realmode_flags,
866 		.maxlen		= sizeof (unsigned long),
867 		.mode		= 0644,
868 		.proc_handler	= proc_doulongvec_minmax,
869 	},
870 #endif
871 #ifdef CONFIG_IA64
872 	{
873 		.procname	= "ignore-unaligned-usertrap",
874 		.data		= &no_unaligned_warning,
875 		.maxlen		= sizeof (int),
876 	 	.mode		= 0644,
877 		.proc_handler	= proc_dointvec,
878 	},
879 	{
880 		.procname	= "unaligned-dump-stack",
881 		.data		= &unaligned_dump_stack,
882 		.maxlen		= sizeof (int),
883 		.mode		= 0644,
884 		.proc_handler	= proc_dointvec,
885 	},
886 #endif
887 #ifdef CONFIG_DETECT_HUNG_TASK
888 	{
889 		.procname	= "hung_task_panic",
890 		.data		= &sysctl_hung_task_panic,
891 		.maxlen		= sizeof(int),
892 		.mode		= 0644,
893 		.proc_handler	= proc_dointvec_minmax,
894 		.extra1		= &zero,
895 		.extra2		= &one,
896 	},
897 	{
898 		.procname	= "hung_task_check_count",
899 		.data		= &sysctl_hung_task_check_count,
900 		.maxlen		= sizeof(unsigned long),
901 		.mode		= 0644,
902 		.proc_handler	= proc_doulongvec_minmax,
903 	},
904 	{
905 		.procname	= "hung_task_timeout_secs",
906 		.data		= &sysctl_hung_task_timeout_secs,
907 		.maxlen		= sizeof(unsigned long),
908 		.mode		= 0644,
909 		.proc_handler	= proc_dohung_task_timeout_secs,
910 	},
911 	{
912 		.procname	= "hung_task_warnings",
913 		.data		= &sysctl_hung_task_warnings,
914 		.maxlen		= sizeof(unsigned long),
915 		.mode		= 0644,
916 		.proc_handler	= proc_doulongvec_minmax,
917 	},
918 #endif
919 #ifdef CONFIG_COMPAT
920 	{
921 		.procname	= "compat-log",
922 		.data		= &compat_log,
923 		.maxlen		= sizeof (int),
924 	 	.mode		= 0644,
925 		.proc_handler	= proc_dointvec,
926 	},
927 #endif
928 #ifdef CONFIG_RT_MUTEXES
929 	{
930 		.procname	= "max_lock_depth",
931 		.data		= &max_lock_depth,
932 		.maxlen		= sizeof(int),
933 		.mode		= 0644,
934 		.proc_handler	= proc_dointvec,
935 	},
936 #endif
937 	{
938 		.procname	= "poweroff_cmd",
939 		.data		= &poweroff_cmd,
940 		.maxlen		= POWEROFF_CMD_PATH_LEN,
941 		.mode		= 0644,
942 		.proc_handler	= proc_dostring,
943 	},
944 #ifdef CONFIG_KEYS
945 	{
946 		.procname	= "keys",
947 		.mode		= 0555,
948 		.child		= key_sysctls,
949 	},
950 #endif
951 #ifdef CONFIG_RCU_TORTURE_TEST
952 	{
953 		.procname       = "rcutorture_runnable",
954 		.data           = &rcutorture_runnable,
955 		.maxlen         = sizeof(int),
956 		.mode           = 0644,
957 		.proc_handler	= proc_dointvec,
958 	},
959 #endif
960 #ifdef CONFIG_PERF_EVENTS
961 	/*
962 	 * User-space scripts rely on the existence of this file
963 	 * as a feature check for perf_events being enabled.
964 	 *
965 	 * So it's an ABI, do not remove!
966 	 */
967 	{
968 		.procname	= "perf_event_paranoid",
969 		.data		= &sysctl_perf_event_paranoid,
970 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
971 		.mode		= 0644,
972 		.proc_handler	= proc_dointvec,
973 	},
974 	{
975 		.procname	= "perf_event_mlock_kb",
976 		.data		= &sysctl_perf_event_mlock,
977 		.maxlen		= sizeof(sysctl_perf_event_mlock),
978 		.mode		= 0644,
979 		.proc_handler	= proc_dointvec,
980 	},
981 	{
982 		.procname	= "perf_event_max_sample_rate",
983 		.data		= &sysctl_perf_event_sample_rate,
984 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
985 		.mode		= 0644,
986 		.proc_handler	= perf_proc_update_handler,
987 	},
988 #endif
989 #ifdef CONFIG_KMEMCHECK
990 	{
991 		.procname	= "kmemcheck",
992 		.data		= &kmemcheck_enabled,
993 		.maxlen		= sizeof(int),
994 		.mode		= 0644,
995 		.proc_handler	= proc_dointvec,
996 	},
997 #endif
998 #ifdef CONFIG_BLOCK
999 	{
1000 		.procname	= "blk_iopoll",
1001 		.data		= &blk_iopoll_enabled,
1002 		.maxlen		= sizeof(int),
1003 		.mode		= 0644,
1004 		.proc_handler	= proc_dointvec,
1005 	},
1006 #endif
1007 	{ }
1008 };
1009 
1010 static struct ctl_table vm_table[] = {
1011 	{
1012 		.procname	= "overcommit_memory",
1013 		.data		= &sysctl_overcommit_memory,
1014 		.maxlen		= sizeof(sysctl_overcommit_memory),
1015 		.mode		= 0644,
1016 		.proc_handler	= proc_dointvec_minmax,
1017 		.extra1		= &zero,
1018 		.extra2		= &two,
1019 	},
1020 	{
1021 		.procname	= "panic_on_oom",
1022 		.data		= &sysctl_panic_on_oom,
1023 		.maxlen		= sizeof(sysctl_panic_on_oom),
1024 		.mode		= 0644,
1025 		.proc_handler	= proc_dointvec_minmax,
1026 		.extra1		= &zero,
1027 		.extra2		= &two,
1028 	},
1029 	{
1030 		.procname	= "oom_kill_allocating_task",
1031 		.data		= &sysctl_oom_kill_allocating_task,
1032 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1033 		.mode		= 0644,
1034 		.proc_handler	= proc_dointvec,
1035 	},
1036 	{
1037 		.procname	= "oom_dump_tasks",
1038 		.data		= &sysctl_oom_dump_tasks,
1039 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1040 		.mode		= 0644,
1041 		.proc_handler	= proc_dointvec,
1042 	},
1043 	{
1044 		.procname	= "overcommit_ratio",
1045 		.data		= &sysctl_overcommit_ratio,
1046 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1047 		.mode		= 0644,
1048 		.proc_handler	= proc_dointvec,
1049 	},
1050 	{
1051 		.procname	= "page-cluster",
1052 		.data		= &page_cluster,
1053 		.maxlen		= sizeof(int),
1054 		.mode		= 0644,
1055 		.proc_handler	= proc_dointvec_minmax,
1056 		.extra1		= &zero,
1057 	},
1058 	{
1059 		.procname	= "dirty_background_ratio",
1060 		.data		= &dirty_background_ratio,
1061 		.maxlen		= sizeof(dirty_background_ratio),
1062 		.mode		= 0644,
1063 		.proc_handler	= dirty_background_ratio_handler,
1064 		.extra1		= &zero,
1065 		.extra2		= &one_hundred,
1066 	},
1067 	{
1068 		.procname	= "dirty_background_bytes",
1069 		.data		= &dirty_background_bytes,
1070 		.maxlen		= sizeof(dirty_background_bytes),
1071 		.mode		= 0644,
1072 		.proc_handler	= dirty_background_bytes_handler,
1073 		.extra1		= &one_ul,
1074 	},
1075 	{
1076 		.procname	= "dirty_ratio",
1077 		.data		= &vm_dirty_ratio,
1078 		.maxlen		= sizeof(vm_dirty_ratio),
1079 		.mode		= 0644,
1080 		.proc_handler	= dirty_ratio_handler,
1081 		.extra1		= &zero,
1082 		.extra2		= &one_hundred,
1083 	},
1084 	{
1085 		.procname	= "dirty_bytes",
1086 		.data		= &vm_dirty_bytes,
1087 		.maxlen		= sizeof(vm_dirty_bytes),
1088 		.mode		= 0644,
1089 		.proc_handler	= dirty_bytes_handler,
1090 		.extra1		= &dirty_bytes_min,
1091 	},
1092 	{
1093 		.procname	= "dirty_writeback_centisecs",
1094 		.data		= &dirty_writeback_interval,
1095 		.maxlen		= sizeof(dirty_writeback_interval),
1096 		.mode		= 0644,
1097 		.proc_handler	= dirty_writeback_centisecs_handler,
1098 	},
1099 	{
1100 		.procname	= "dirty_expire_centisecs",
1101 		.data		= &dirty_expire_interval,
1102 		.maxlen		= sizeof(dirty_expire_interval),
1103 		.mode		= 0644,
1104 		.proc_handler	= proc_dointvec_minmax,
1105 		.extra1		= &zero,
1106 	},
1107 	{
1108 		.procname	= "nr_pdflush_threads",
1109 		.data		= &nr_pdflush_threads,
1110 		.maxlen		= sizeof nr_pdflush_threads,
1111 		.mode		= 0444 /* read-only*/,
1112 		.proc_handler	= proc_dointvec,
1113 	},
1114 	{
1115 		.procname	= "swappiness",
1116 		.data		= &vm_swappiness,
1117 		.maxlen		= sizeof(vm_swappiness),
1118 		.mode		= 0644,
1119 		.proc_handler	= proc_dointvec_minmax,
1120 		.extra1		= &zero,
1121 		.extra2		= &one_hundred,
1122 	},
1123 #ifdef CONFIG_HUGETLB_PAGE
1124 	{
1125 		.procname	= "nr_hugepages",
1126 		.data		= NULL,
1127 		.maxlen		= sizeof(unsigned long),
1128 		.mode		= 0644,
1129 		.proc_handler	= hugetlb_sysctl_handler,
1130 		.extra1		= (void *)&hugetlb_zero,
1131 		.extra2		= (void *)&hugetlb_infinity,
1132 	},
1133 #ifdef CONFIG_NUMA
1134 	{
1135 		.procname       = "nr_hugepages_mempolicy",
1136 		.data           = NULL,
1137 		.maxlen         = sizeof(unsigned long),
1138 		.mode           = 0644,
1139 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1140 		.extra1		= (void *)&hugetlb_zero,
1141 		.extra2		= (void *)&hugetlb_infinity,
1142 	},
1143 #endif
1144 	 {
1145 		.procname	= "hugetlb_shm_group",
1146 		.data		= &sysctl_hugetlb_shm_group,
1147 		.maxlen		= sizeof(gid_t),
1148 		.mode		= 0644,
1149 		.proc_handler	= proc_dointvec,
1150 	 },
1151 	 {
1152 		.procname	= "hugepages_treat_as_movable",
1153 		.data		= &hugepages_treat_as_movable,
1154 		.maxlen		= sizeof(int),
1155 		.mode		= 0644,
1156 		.proc_handler	= hugetlb_treat_movable_handler,
1157 	},
1158 	{
1159 		.procname	= "nr_overcommit_hugepages",
1160 		.data		= NULL,
1161 		.maxlen		= sizeof(unsigned long),
1162 		.mode		= 0644,
1163 		.proc_handler	= hugetlb_overcommit_handler,
1164 		.extra1		= (void *)&hugetlb_zero,
1165 		.extra2		= (void *)&hugetlb_infinity,
1166 	},
1167 #endif
1168 	{
1169 		.procname	= "lowmem_reserve_ratio",
1170 		.data		= &sysctl_lowmem_reserve_ratio,
1171 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1172 		.mode		= 0644,
1173 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1174 	},
1175 	{
1176 		.procname	= "drop_caches",
1177 		.data		= &sysctl_drop_caches,
1178 		.maxlen		= sizeof(int),
1179 		.mode		= 0644,
1180 		.proc_handler	= drop_caches_sysctl_handler,
1181 		.extra1		= &one,
1182 		.extra2		= &three,
1183 	},
1184 #ifdef CONFIG_COMPACTION
1185 	{
1186 		.procname	= "compact_memory",
1187 		.data		= &sysctl_compact_memory,
1188 		.maxlen		= sizeof(int),
1189 		.mode		= 0200,
1190 		.proc_handler	= sysctl_compaction_handler,
1191 	},
1192 	{
1193 		.procname	= "extfrag_threshold",
1194 		.data		= &sysctl_extfrag_threshold,
1195 		.maxlen		= sizeof(int),
1196 		.mode		= 0644,
1197 		.proc_handler	= sysctl_extfrag_handler,
1198 		.extra1		= &min_extfrag_threshold,
1199 		.extra2		= &max_extfrag_threshold,
1200 	},
1201 
1202 #endif /* CONFIG_COMPACTION */
1203 	{
1204 		.procname	= "min_free_kbytes",
1205 		.data		= &min_free_kbytes,
1206 		.maxlen		= sizeof(min_free_kbytes),
1207 		.mode		= 0644,
1208 		.proc_handler	= min_free_kbytes_sysctl_handler,
1209 		.extra1		= &zero,
1210 	},
1211 	{
1212 		.procname	= "percpu_pagelist_fraction",
1213 		.data		= &percpu_pagelist_fraction,
1214 		.maxlen		= sizeof(percpu_pagelist_fraction),
1215 		.mode		= 0644,
1216 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1217 		.extra1		= &min_percpu_pagelist_fract,
1218 	},
1219 #ifdef CONFIG_MMU
1220 	{
1221 		.procname	= "max_map_count",
1222 		.data		= &sysctl_max_map_count,
1223 		.maxlen		= sizeof(sysctl_max_map_count),
1224 		.mode		= 0644,
1225 		.proc_handler	= proc_dointvec_minmax,
1226 		.extra1		= &zero,
1227 	},
1228 #else
1229 	{
1230 		.procname	= "nr_trim_pages",
1231 		.data		= &sysctl_nr_trim_pages,
1232 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1233 		.mode		= 0644,
1234 		.proc_handler	= proc_dointvec_minmax,
1235 		.extra1		= &zero,
1236 	},
1237 #endif
1238 	{
1239 		.procname	= "laptop_mode",
1240 		.data		= &laptop_mode,
1241 		.maxlen		= sizeof(laptop_mode),
1242 		.mode		= 0644,
1243 		.proc_handler	= proc_dointvec_jiffies,
1244 	},
1245 	{
1246 		.procname	= "block_dump",
1247 		.data		= &block_dump,
1248 		.maxlen		= sizeof(block_dump),
1249 		.mode		= 0644,
1250 		.proc_handler	= proc_dointvec,
1251 		.extra1		= &zero,
1252 	},
1253 	{
1254 		.procname	= "vfs_cache_pressure",
1255 		.data		= &sysctl_vfs_cache_pressure,
1256 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1257 		.mode		= 0644,
1258 		.proc_handler	= proc_dointvec,
1259 		.extra1		= &zero,
1260 	},
1261 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1262 	{
1263 		.procname	= "legacy_va_layout",
1264 		.data		= &sysctl_legacy_va_layout,
1265 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1266 		.mode		= 0644,
1267 		.proc_handler	= proc_dointvec,
1268 		.extra1		= &zero,
1269 	},
1270 #endif
1271 #ifdef CONFIG_NUMA
1272 	{
1273 		.procname	= "zone_reclaim_mode",
1274 		.data		= &zone_reclaim_mode,
1275 		.maxlen		= sizeof(zone_reclaim_mode),
1276 		.mode		= 0644,
1277 		.proc_handler	= proc_dointvec,
1278 		.extra1		= &zero,
1279 	},
1280 	{
1281 		.procname	= "min_unmapped_ratio",
1282 		.data		= &sysctl_min_unmapped_ratio,
1283 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1284 		.mode		= 0644,
1285 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1286 		.extra1		= &zero,
1287 		.extra2		= &one_hundred,
1288 	},
1289 	{
1290 		.procname	= "min_slab_ratio",
1291 		.data		= &sysctl_min_slab_ratio,
1292 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1293 		.mode		= 0644,
1294 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1295 		.extra1		= &zero,
1296 		.extra2		= &one_hundred,
1297 	},
1298 #endif
1299 #ifdef CONFIG_SMP
1300 	{
1301 		.procname	= "stat_interval",
1302 		.data		= &sysctl_stat_interval,
1303 		.maxlen		= sizeof(sysctl_stat_interval),
1304 		.mode		= 0644,
1305 		.proc_handler	= proc_dointvec_jiffies,
1306 	},
1307 #endif
1308 #ifdef CONFIG_MMU
1309 	{
1310 		.procname	= "mmap_min_addr",
1311 		.data		= &dac_mmap_min_addr,
1312 		.maxlen		= sizeof(unsigned long),
1313 		.mode		= 0644,
1314 		.proc_handler	= mmap_min_addr_handler,
1315 	},
1316 #endif
1317 #ifdef CONFIG_NUMA
1318 	{
1319 		.procname	= "numa_zonelist_order",
1320 		.data		= &numa_zonelist_order,
1321 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1322 		.mode		= 0644,
1323 		.proc_handler	= numa_zonelist_order_handler,
1324 	},
1325 #endif
1326 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1327    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1328 	{
1329 		.procname	= "vdso_enabled",
1330 		.data		= &vdso_enabled,
1331 		.maxlen		= sizeof(vdso_enabled),
1332 		.mode		= 0644,
1333 		.proc_handler	= proc_dointvec,
1334 		.extra1		= &zero,
1335 	},
1336 #endif
1337 #ifdef CONFIG_HIGHMEM
1338 	{
1339 		.procname	= "highmem_is_dirtyable",
1340 		.data		= &vm_highmem_is_dirtyable,
1341 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1342 		.mode		= 0644,
1343 		.proc_handler	= proc_dointvec_minmax,
1344 		.extra1		= &zero,
1345 		.extra2		= &one,
1346 	},
1347 #endif
1348 	{
1349 		.procname	= "scan_unevictable_pages",
1350 		.data		= &scan_unevictable_pages,
1351 		.maxlen		= sizeof(scan_unevictable_pages),
1352 		.mode		= 0644,
1353 		.proc_handler	= scan_unevictable_handler,
1354 	},
1355 #ifdef CONFIG_MEMORY_FAILURE
1356 	{
1357 		.procname	= "memory_failure_early_kill",
1358 		.data		= &sysctl_memory_failure_early_kill,
1359 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1360 		.mode		= 0644,
1361 		.proc_handler	= proc_dointvec_minmax,
1362 		.extra1		= &zero,
1363 		.extra2		= &one,
1364 	},
1365 	{
1366 		.procname	= "memory_failure_recovery",
1367 		.data		= &sysctl_memory_failure_recovery,
1368 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1369 		.mode		= 0644,
1370 		.proc_handler	= proc_dointvec_minmax,
1371 		.extra1		= &zero,
1372 		.extra2		= &one,
1373 	},
1374 #endif
1375 	{ }
1376 };
1377 
1378 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1379 static struct ctl_table binfmt_misc_table[] = {
1380 	{ }
1381 };
1382 #endif
1383 
1384 static struct ctl_table fs_table[] = {
1385 	{
1386 		.procname	= "inode-nr",
1387 		.data		= &inodes_stat,
1388 		.maxlen		= 2*sizeof(int),
1389 		.mode		= 0444,
1390 		.proc_handler	= proc_nr_inodes,
1391 	},
1392 	{
1393 		.procname	= "inode-state",
1394 		.data		= &inodes_stat,
1395 		.maxlen		= 7*sizeof(int),
1396 		.mode		= 0444,
1397 		.proc_handler	= proc_nr_inodes,
1398 	},
1399 	{
1400 		.procname	= "file-nr",
1401 		.data		= &files_stat,
1402 		.maxlen		= sizeof(files_stat),
1403 		.mode		= 0444,
1404 		.proc_handler	= proc_nr_files,
1405 	},
1406 	{
1407 		.procname	= "file-max",
1408 		.data		= &files_stat.max_files,
1409 		.maxlen		= sizeof(files_stat.max_files),
1410 		.mode		= 0644,
1411 		.proc_handler	= proc_doulongvec_minmax,
1412 	},
1413 	{
1414 		.procname	= "nr_open",
1415 		.data		= &sysctl_nr_open,
1416 		.maxlen		= sizeof(int),
1417 		.mode		= 0644,
1418 		.proc_handler	= proc_dointvec_minmax,
1419 		.extra1		= &sysctl_nr_open_min,
1420 		.extra2		= &sysctl_nr_open_max,
1421 	},
1422 	{
1423 		.procname	= "dentry-state",
1424 		.data		= &dentry_stat,
1425 		.maxlen		= 6*sizeof(int),
1426 		.mode		= 0444,
1427 		.proc_handler	= proc_nr_dentry,
1428 	},
1429 	{
1430 		.procname	= "overflowuid",
1431 		.data		= &fs_overflowuid,
1432 		.maxlen		= sizeof(int),
1433 		.mode		= 0644,
1434 		.proc_handler	= proc_dointvec_minmax,
1435 		.extra1		= &minolduid,
1436 		.extra2		= &maxolduid,
1437 	},
1438 	{
1439 		.procname	= "overflowgid",
1440 		.data		= &fs_overflowgid,
1441 		.maxlen		= sizeof(int),
1442 		.mode		= 0644,
1443 		.proc_handler	= proc_dointvec_minmax,
1444 		.extra1		= &minolduid,
1445 		.extra2		= &maxolduid,
1446 	},
1447 #ifdef CONFIG_FILE_LOCKING
1448 	{
1449 		.procname	= "leases-enable",
1450 		.data		= &leases_enable,
1451 		.maxlen		= sizeof(int),
1452 		.mode		= 0644,
1453 		.proc_handler	= proc_dointvec,
1454 	},
1455 #endif
1456 #ifdef CONFIG_DNOTIFY
1457 	{
1458 		.procname	= "dir-notify-enable",
1459 		.data		= &dir_notify_enable,
1460 		.maxlen		= sizeof(int),
1461 		.mode		= 0644,
1462 		.proc_handler	= proc_dointvec,
1463 	},
1464 #endif
1465 #ifdef CONFIG_MMU
1466 #ifdef CONFIG_FILE_LOCKING
1467 	{
1468 		.procname	= "lease-break-time",
1469 		.data		= &lease_break_time,
1470 		.maxlen		= sizeof(int),
1471 		.mode		= 0644,
1472 		.proc_handler	= proc_dointvec,
1473 	},
1474 #endif
1475 #ifdef CONFIG_AIO
1476 	{
1477 		.procname	= "aio-nr",
1478 		.data		= &aio_nr,
1479 		.maxlen		= sizeof(aio_nr),
1480 		.mode		= 0444,
1481 		.proc_handler	= proc_doulongvec_minmax,
1482 	},
1483 	{
1484 		.procname	= "aio-max-nr",
1485 		.data		= &aio_max_nr,
1486 		.maxlen		= sizeof(aio_max_nr),
1487 		.mode		= 0644,
1488 		.proc_handler	= proc_doulongvec_minmax,
1489 	},
1490 #endif /* CONFIG_AIO */
1491 #ifdef CONFIG_INOTIFY_USER
1492 	{
1493 		.procname	= "inotify",
1494 		.mode		= 0555,
1495 		.child		= inotify_table,
1496 	},
1497 #endif
1498 #ifdef CONFIG_EPOLL
1499 	{
1500 		.procname	= "epoll",
1501 		.mode		= 0555,
1502 		.child		= epoll_table,
1503 	},
1504 #endif
1505 #endif
1506 	{
1507 		.procname	= "suid_dumpable",
1508 		.data		= &suid_dumpable,
1509 		.maxlen		= sizeof(int),
1510 		.mode		= 0644,
1511 		.proc_handler	= proc_dointvec_minmax,
1512 		.extra1		= &zero,
1513 		.extra2		= &two,
1514 	},
1515 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1516 	{
1517 		.procname	= "binfmt_misc",
1518 		.mode		= 0555,
1519 		.child		= binfmt_misc_table,
1520 	},
1521 #endif
1522 	{
1523 		.procname	= "pipe-max-size",
1524 		.data		= &pipe_max_size,
1525 		.maxlen		= sizeof(int),
1526 		.mode		= 0644,
1527 		.proc_handler	= &pipe_proc_fn,
1528 		.extra1		= &pipe_min_size,
1529 	},
1530 	{ }
1531 };
1532 
1533 static struct ctl_table debug_table[] = {
1534 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1535     defined(CONFIG_S390) || defined(CONFIG_TILE)
1536 	{
1537 		.procname	= "exception-trace",
1538 		.data		= &show_unhandled_signals,
1539 		.maxlen		= sizeof(int),
1540 		.mode		= 0644,
1541 		.proc_handler	= proc_dointvec
1542 	},
1543 #endif
1544 #if defined(CONFIG_OPTPROBES)
1545 	{
1546 		.procname	= "kprobes-optimization",
1547 		.data		= &sysctl_kprobes_optimization,
1548 		.maxlen		= sizeof(int),
1549 		.mode		= 0644,
1550 		.proc_handler	= proc_kprobes_optimization_handler,
1551 		.extra1		= &zero,
1552 		.extra2		= &one,
1553 	},
1554 #endif
1555 	{ }
1556 };
1557 
1558 static struct ctl_table dev_table[] = {
1559 	{ }
1560 };
1561 
1562 static DEFINE_SPINLOCK(sysctl_lock);
1563 
1564 /* called under sysctl_lock */
1565 static int use_table(struct ctl_table_header *p)
1566 {
1567 	if (unlikely(p->unregistering))
1568 		return 0;
1569 	p->used++;
1570 	return 1;
1571 }
1572 
1573 /* called under sysctl_lock */
1574 static void unuse_table(struct ctl_table_header *p)
1575 {
1576 	if (!--p->used)
1577 		if (unlikely(p->unregistering))
1578 			complete(p->unregistering);
1579 }
1580 
1581 /* called under sysctl_lock, will reacquire if has to wait */
1582 static void start_unregistering(struct ctl_table_header *p)
1583 {
1584 	/*
1585 	 * if p->used is 0, nobody will ever touch that entry again;
1586 	 * we'll eliminate all paths to it before dropping sysctl_lock
1587 	 */
1588 	if (unlikely(p->used)) {
1589 		struct completion wait;
1590 		init_completion(&wait);
1591 		p->unregistering = &wait;
1592 		spin_unlock(&sysctl_lock);
1593 		wait_for_completion(&wait);
1594 		spin_lock(&sysctl_lock);
1595 	} else {
1596 		/* anything non-NULL; we'll never dereference it */
1597 		p->unregistering = ERR_PTR(-EINVAL);
1598 	}
1599 	/*
1600 	 * do not remove from the list until nobody holds it; walking the
1601 	 * list in do_sysctl() relies on that.
1602 	 */
1603 	list_del_init(&p->ctl_entry);
1604 }
1605 
1606 void sysctl_head_get(struct ctl_table_header *head)
1607 {
1608 	spin_lock(&sysctl_lock);
1609 	head->count++;
1610 	spin_unlock(&sysctl_lock);
1611 }
1612 
1613 void sysctl_head_put(struct ctl_table_header *head)
1614 {
1615 	spin_lock(&sysctl_lock);
1616 	if (!--head->count)
1617 		kfree_rcu(head, rcu);
1618 	spin_unlock(&sysctl_lock);
1619 }
1620 
1621 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1622 {
1623 	if (!head)
1624 		BUG();
1625 	spin_lock(&sysctl_lock);
1626 	if (!use_table(head))
1627 		head = ERR_PTR(-ENOENT);
1628 	spin_unlock(&sysctl_lock);
1629 	return head;
1630 }
1631 
1632 void sysctl_head_finish(struct ctl_table_header *head)
1633 {
1634 	if (!head)
1635 		return;
1636 	spin_lock(&sysctl_lock);
1637 	unuse_table(head);
1638 	spin_unlock(&sysctl_lock);
1639 }
1640 
1641 static struct ctl_table_set *
1642 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1643 {
1644 	struct ctl_table_set *set = &root->default_set;
1645 	if (root->lookup)
1646 		set = root->lookup(root, namespaces);
1647 	return set;
1648 }
1649 
1650 static struct list_head *
1651 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1652 {
1653 	struct ctl_table_set *set = lookup_header_set(root, namespaces);
1654 	return &set->list;
1655 }
1656 
1657 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1658 					    struct ctl_table_header *prev)
1659 {
1660 	struct ctl_table_root *root;
1661 	struct list_head *header_list;
1662 	struct ctl_table_header *head;
1663 	struct list_head *tmp;
1664 
1665 	spin_lock(&sysctl_lock);
1666 	if (prev) {
1667 		head = prev;
1668 		tmp = &prev->ctl_entry;
1669 		unuse_table(prev);
1670 		goto next;
1671 	}
1672 	tmp = &root_table_header.ctl_entry;
1673 	for (;;) {
1674 		head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1675 
1676 		if (!use_table(head))
1677 			goto next;
1678 		spin_unlock(&sysctl_lock);
1679 		return head;
1680 	next:
1681 		root = head->root;
1682 		tmp = tmp->next;
1683 		header_list = lookup_header_list(root, namespaces);
1684 		if (tmp != header_list)
1685 			continue;
1686 
1687 		do {
1688 			root = list_entry(root->root_list.next,
1689 					struct ctl_table_root, root_list);
1690 			if (root == &sysctl_table_root)
1691 				goto out;
1692 			header_list = lookup_header_list(root, namespaces);
1693 		} while (list_empty(header_list));
1694 		tmp = header_list->next;
1695 	}
1696 out:
1697 	spin_unlock(&sysctl_lock);
1698 	return NULL;
1699 }
1700 
1701 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1702 {
1703 	return __sysctl_head_next(current->nsproxy, prev);
1704 }
1705 
1706 void register_sysctl_root(struct ctl_table_root *root)
1707 {
1708 	spin_lock(&sysctl_lock);
1709 	list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1710 	spin_unlock(&sysctl_lock);
1711 }
1712 
1713 /*
1714  * sysctl_perm does NOT grant the superuser all rights automatically, because
1715  * some sysctl variables are readonly even to root.
1716  */
1717 
1718 static int test_perm(int mode, int op)
1719 {
1720 	if (!current_euid())
1721 		mode >>= 6;
1722 	else if (in_egroup_p(0))
1723 		mode >>= 3;
1724 	if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1725 		return 0;
1726 	return -EACCES;
1727 }
1728 
1729 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1730 {
1731 	int mode;
1732 
1733 	if (root->permissions)
1734 		mode = root->permissions(root, current->nsproxy, table);
1735 	else
1736 		mode = table->mode;
1737 
1738 	return test_perm(mode, op);
1739 }
1740 
1741 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1742 {
1743 	for (; table->procname; table++) {
1744 		table->parent = parent;
1745 		if (table->child)
1746 			sysctl_set_parent(table, table->child);
1747 	}
1748 }
1749 
1750 static __init int sysctl_init(void)
1751 {
1752 	sysctl_set_parent(NULL, root_table);
1753 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1754 	sysctl_check_table(current->nsproxy, root_table);
1755 #endif
1756 	return 0;
1757 }
1758 
1759 core_initcall(sysctl_init);
1760 
1761 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1762 				      struct ctl_table *table)
1763 {
1764 	struct ctl_table *p;
1765 	const char *s = branch->procname;
1766 
1767 	/* branch should have named subdirectory as its first element */
1768 	if (!s || !branch->child)
1769 		return NULL;
1770 
1771 	/* ... and nothing else */
1772 	if (branch[1].procname)
1773 		return NULL;
1774 
1775 	/* table should contain subdirectory with the same name */
1776 	for (p = table; p->procname; p++) {
1777 		if (!p->child)
1778 			continue;
1779 		if (p->procname && strcmp(p->procname, s) == 0)
1780 			return p;
1781 	}
1782 	return NULL;
1783 }
1784 
1785 /* see if attaching q to p would be an improvement */
1786 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1787 {
1788 	struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1789 	struct ctl_table *next;
1790 	int is_better = 0;
1791 	int not_in_parent = !p->attached_by;
1792 
1793 	while ((next = is_branch_in(by, to)) != NULL) {
1794 		if (by == q->attached_by)
1795 			is_better = 1;
1796 		if (to == p->attached_by)
1797 			not_in_parent = 1;
1798 		by = by->child;
1799 		to = next->child;
1800 	}
1801 
1802 	if (is_better && not_in_parent) {
1803 		q->attached_by = by;
1804 		q->attached_to = to;
1805 		q->parent = p;
1806 	}
1807 }
1808 
1809 /**
1810  * __register_sysctl_paths - register a sysctl hierarchy
1811  * @root: List of sysctl headers to register on
1812  * @namespaces: Data to compute which lists of sysctl entries are visible
1813  * @path: The path to the directory the sysctl table is in.
1814  * @table: the top-level table structure
1815  *
1816  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1817  * array. A completely 0 filled entry terminates the table.
1818  *
1819  * The members of the &struct ctl_table structure are used as follows:
1820  *
1821  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1822  *            enter a sysctl file
1823  *
1824  * data - a pointer to data for use by proc_handler
1825  *
1826  * maxlen - the maximum size in bytes of the data
1827  *
1828  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1829  *
1830  * child - a pointer to the child sysctl table if this entry is a directory, or
1831  *         %NULL.
1832  *
1833  * proc_handler - the text handler routine (described below)
1834  *
1835  * de - for internal use by the sysctl routines
1836  *
1837  * extra1, extra2 - extra pointers usable by the proc handler routines
1838  *
1839  * Leaf nodes in the sysctl tree will be represented by a single file
1840  * under /proc; non-leaf nodes will be represented by directories.
1841  *
1842  * sysctl(2) can automatically manage read and write requests through
1843  * the sysctl table.  The data and maxlen fields of the ctl_table
1844  * struct enable minimal validation of the values being written to be
1845  * performed, and the mode field allows minimal authentication.
1846  *
1847  * There must be a proc_handler routine for any terminal nodes
1848  * mirrored under /proc/sys (non-terminals are handled by a built-in
1849  * directory handler).  Several default handlers are available to
1850  * cover common cases -
1851  *
1852  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1853  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1854  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1855  *
1856  * It is the handler's job to read the input buffer from user memory
1857  * and process it. The handler should return 0 on success.
1858  *
1859  * This routine returns %NULL on a failure to register, and a pointer
1860  * to the table header on success.
1861  */
1862 struct ctl_table_header *__register_sysctl_paths(
1863 	struct ctl_table_root *root,
1864 	struct nsproxy *namespaces,
1865 	const struct ctl_path *path, struct ctl_table *table)
1866 {
1867 	struct ctl_table_header *header;
1868 	struct ctl_table *new, **prevp;
1869 	unsigned int n, npath;
1870 	struct ctl_table_set *set;
1871 
1872 	/* Count the path components */
1873 	for (npath = 0; path[npath].procname; ++npath)
1874 		;
1875 
1876 	/*
1877 	 * For each path component, allocate a 2-element ctl_table array.
1878 	 * The first array element will be filled with the sysctl entry
1879 	 * for this, the second will be the sentinel (procname == 0).
1880 	 *
1881 	 * We allocate everything in one go so that we don't have to
1882 	 * worry about freeing additional memory in unregister_sysctl_table.
1883 	 */
1884 	header = kzalloc(sizeof(struct ctl_table_header) +
1885 			 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1886 	if (!header)
1887 		return NULL;
1888 
1889 	new = (struct ctl_table *) (header + 1);
1890 
1891 	/* Now connect the dots */
1892 	prevp = &header->ctl_table;
1893 	for (n = 0; n < npath; ++n, ++path) {
1894 		/* Copy the procname */
1895 		new->procname = path->procname;
1896 		new->mode     = 0555;
1897 
1898 		*prevp = new;
1899 		prevp = &new->child;
1900 
1901 		new += 2;
1902 	}
1903 	*prevp = table;
1904 	header->ctl_table_arg = table;
1905 
1906 	INIT_LIST_HEAD(&header->ctl_entry);
1907 	header->used = 0;
1908 	header->unregistering = NULL;
1909 	header->root = root;
1910 	sysctl_set_parent(NULL, header->ctl_table);
1911 	header->count = 1;
1912 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1913 	if (sysctl_check_table(namespaces, header->ctl_table)) {
1914 		kfree(header);
1915 		return NULL;
1916 	}
1917 #endif
1918 	spin_lock(&sysctl_lock);
1919 	header->set = lookup_header_set(root, namespaces);
1920 	header->attached_by = header->ctl_table;
1921 	header->attached_to = root_table;
1922 	header->parent = &root_table_header;
1923 	for (set = header->set; set; set = set->parent) {
1924 		struct ctl_table_header *p;
1925 		list_for_each_entry(p, &set->list, ctl_entry) {
1926 			if (p->unregistering)
1927 				continue;
1928 			try_attach(p, header);
1929 		}
1930 	}
1931 	header->parent->count++;
1932 	list_add_tail(&header->ctl_entry, &header->set->list);
1933 	spin_unlock(&sysctl_lock);
1934 
1935 	return header;
1936 }
1937 
1938 /**
1939  * register_sysctl_table_path - register a sysctl table hierarchy
1940  * @path: The path to the directory the sysctl table is in.
1941  * @table: the top-level table structure
1942  *
1943  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1944  * array. A completely 0 filled entry terminates the table.
1945  *
1946  * See __register_sysctl_paths for more details.
1947  */
1948 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1949 						struct ctl_table *table)
1950 {
1951 	return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1952 					path, table);
1953 }
1954 
1955 /**
1956  * register_sysctl_table - register a sysctl table hierarchy
1957  * @table: the top-level table structure
1958  *
1959  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1960  * array. A completely 0 filled entry terminates the table.
1961  *
1962  * See register_sysctl_paths for more details.
1963  */
1964 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1965 {
1966 	static const struct ctl_path null_path[] = { {} };
1967 
1968 	return register_sysctl_paths(null_path, table);
1969 }
1970 
1971 /**
1972  * unregister_sysctl_table - unregister a sysctl table hierarchy
1973  * @header: the header returned from register_sysctl_table
1974  *
1975  * Unregisters the sysctl table and all children. proc entries may not
1976  * actually be removed until they are no longer used by anyone.
1977  */
1978 void unregister_sysctl_table(struct ctl_table_header * header)
1979 {
1980 	might_sleep();
1981 
1982 	if (header == NULL)
1983 		return;
1984 
1985 	spin_lock(&sysctl_lock);
1986 	start_unregistering(header);
1987 	if (!--header->parent->count) {
1988 		WARN_ON(1);
1989 		kfree_rcu(header->parent, rcu);
1990 	}
1991 	if (!--header->count)
1992 		kfree_rcu(header, rcu);
1993 	spin_unlock(&sysctl_lock);
1994 }
1995 
1996 int sysctl_is_seen(struct ctl_table_header *p)
1997 {
1998 	struct ctl_table_set *set = p->set;
1999 	int res;
2000 	spin_lock(&sysctl_lock);
2001 	if (p->unregistering)
2002 		res = 0;
2003 	else if (!set->is_seen)
2004 		res = 1;
2005 	else
2006 		res = set->is_seen(set);
2007 	spin_unlock(&sysctl_lock);
2008 	return res;
2009 }
2010 
2011 void setup_sysctl_set(struct ctl_table_set *p,
2012 	struct ctl_table_set *parent,
2013 	int (*is_seen)(struct ctl_table_set *))
2014 {
2015 	INIT_LIST_HEAD(&p->list);
2016 	p->parent = parent ? parent : &sysctl_table_root.default_set;
2017 	p->is_seen = is_seen;
2018 }
2019 
2020 #else /* !CONFIG_SYSCTL */
2021 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2022 {
2023 	return NULL;
2024 }
2025 
2026 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2027 						    struct ctl_table *table)
2028 {
2029 	return NULL;
2030 }
2031 
2032 void unregister_sysctl_table(struct ctl_table_header * table)
2033 {
2034 }
2035 
2036 void setup_sysctl_set(struct ctl_table_set *p,
2037 	struct ctl_table_set *parent,
2038 	int (*is_seen)(struct ctl_table_set *))
2039 {
2040 }
2041 
2042 void sysctl_head_put(struct ctl_table_header *head)
2043 {
2044 }
2045 
2046 #endif /* CONFIG_SYSCTL */
2047 
2048 /*
2049  * /proc/sys support
2050  */
2051 
2052 #ifdef CONFIG_PROC_SYSCTL
2053 
2054 static int _proc_do_string(void* data, int maxlen, int write,
2055 			   void __user *buffer,
2056 			   size_t *lenp, loff_t *ppos)
2057 {
2058 	size_t len;
2059 	char __user *p;
2060 	char c;
2061 
2062 	if (!data || !maxlen || !*lenp) {
2063 		*lenp = 0;
2064 		return 0;
2065 	}
2066 
2067 	if (write) {
2068 		len = 0;
2069 		p = buffer;
2070 		while (len < *lenp) {
2071 			if (get_user(c, p++))
2072 				return -EFAULT;
2073 			if (c == 0 || c == '\n')
2074 				break;
2075 			len++;
2076 		}
2077 		if (len >= maxlen)
2078 			len = maxlen-1;
2079 		if(copy_from_user(data, buffer, len))
2080 			return -EFAULT;
2081 		((char *) data)[len] = 0;
2082 		*ppos += *lenp;
2083 	} else {
2084 		len = strlen(data);
2085 		if (len > maxlen)
2086 			len = maxlen;
2087 
2088 		if (*ppos > len) {
2089 			*lenp = 0;
2090 			return 0;
2091 		}
2092 
2093 		data += *ppos;
2094 		len  -= *ppos;
2095 
2096 		if (len > *lenp)
2097 			len = *lenp;
2098 		if (len)
2099 			if(copy_to_user(buffer, data, len))
2100 				return -EFAULT;
2101 		if (len < *lenp) {
2102 			if(put_user('\n', ((char __user *) buffer) + len))
2103 				return -EFAULT;
2104 			len++;
2105 		}
2106 		*lenp = len;
2107 		*ppos += len;
2108 	}
2109 	return 0;
2110 }
2111 
2112 /**
2113  * proc_dostring - read a string sysctl
2114  * @table: the sysctl table
2115  * @write: %TRUE if this is a write to the sysctl file
2116  * @buffer: the user buffer
2117  * @lenp: the size of the user buffer
2118  * @ppos: file position
2119  *
2120  * Reads/writes a string from/to the user buffer. If the kernel
2121  * buffer provided is not large enough to hold the string, the
2122  * string is truncated. The copied string is %NULL-terminated.
2123  * If the string is being read by the user process, it is copied
2124  * and a newline '\n' is added. It is truncated if the buffer is
2125  * not large enough.
2126  *
2127  * Returns 0 on success.
2128  */
2129 int proc_dostring(struct ctl_table *table, int write,
2130 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2131 {
2132 	return _proc_do_string(table->data, table->maxlen, write,
2133 			       buffer, lenp, ppos);
2134 }
2135 
2136 static size_t proc_skip_spaces(char **buf)
2137 {
2138 	size_t ret;
2139 	char *tmp = skip_spaces(*buf);
2140 	ret = tmp - *buf;
2141 	*buf = tmp;
2142 	return ret;
2143 }
2144 
2145 static void proc_skip_char(char **buf, size_t *size, const char v)
2146 {
2147 	while (*size) {
2148 		if (**buf != v)
2149 			break;
2150 		(*size)--;
2151 		(*buf)++;
2152 	}
2153 }
2154 
2155 #define TMPBUFLEN 22
2156 /**
2157  * proc_get_long - reads an ASCII formatted integer from a user buffer
2158  *
2159  * @buf: a kernel buffer
2160  * @size: size of the kernel buffer
2161  * @val: this is where the number will be stored
2162  * @neg: set to %TRUE if number is negative
2163  * @perm_tr: a vector which contains the allowed trailers
2164  * @perm_tr_len: size of the perm_tr vector
2165  * @tr: pointer to store the trailer character
2166  *
2167  * In case of success %0 is returned and @buf and @size are updated with
2168  * the amount of bytes read. If @tr is non-NULL and a trailing
2169  * character exists (size is non-zero after returning from this
2170  * function), @tr is updated with the trailing character.
2171  */
2172 static int proc_get_long(char **buf, size_t *size,
2173 			  unsigned long *val, bool *neg,
2174 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2175 {
2176 	int len;
2177 	char *p, tmp[TMPBUFLEN];
2178 
2179 	if (!*size)
2180 		return -EINVAL;
2181 
2182 	len = *size;
2183 	if (len > TMPBUFLEN - 1)
2184 		len = TMPBUFLEN - 1;
2185 
2186 	memcpy(tmp, *buf, len);
2187 
2188 	tmp[len] = 0;
2189 	p = tmp;
2190 	if (*p == '-' && *size > 1) {
2191 		*neg = true;
2192 		p++;
2193 	} else
2194 		*neg = false;
2195 	if (!isdigit(*p))
2196 		return -EINVAL;
2197 
2198 	*val = simple_strtoul(p, &p, 0);
2199 
2200 	len = p - tmp;
2201 
2202 	/* We don't know if the next char is whitespace thus we may accept
2203 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2204 	 * (e.g. 123...1). So lets not allow such large numbers. */
2205 	if (len == TMPBUFLEN - 1)
2206 		return -EINVAL;
2207 
2208 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2209 		return -EINVAL;
2210 
2211 	if (tr && (len < *size))
2212 		*tr = *p;
2213 
2214 	*buf += len;
2215 	*size -= len;
2216 
2217 	return 0;
2218 }
2219 
2220 /**
2221  * proc_put_long - converts an integer to a decimal ASCII formatted string
2222  *
2223  * @buf: the user buffer
2224  * @size: the size of the user buffer
2225  * @val: the integer to be converted
2226  * @neg: sign of the number, %TRUE for negative
2227  *
2228  * In case of success %0 is returned and @buf and @size are updated with
2229  * the amount of bytes written.
2230  */
2231 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2232 			  bool neg)
2233 {
2234 	int len;
2235 	char tmp[TMPBUFLEN], *p = tmp;
2236 
2237 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2238 	len = strlen(tmp);
2239 	if (len > *size)
2240 		len = *size;
2241 	if (copy_to_user(*buf, tmp, len))
2242 		return -EFAULT;
2243 	*size -= len;
2244 	*buf += len;
2245 	return 0;
2246 }
2247 #undef TMPBUFLEN
2248 
2249 static int proc_put_char(void __user **buf, size_t *size, char c)
2250 {
2251 	if (*size) {
2252 		char __user **buffer = (char __user **)buf;
2253 		if (put_user(c, *buffer))
2254 			return -EFAULT;
2255 		(*size)--, (*buffer)++;
2256 		*buf = *buffer;
2257 	}
2258 	return 0;
2259 }
2260 
2261 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2262 				 int *valp,
2263 				 int write, void *data)
2264 {
2265 	if (write) {
2266 		*valp = *negp ? -*lvalp : *lvalp;
2267 	} else {
2268 		int val = *valp;
2269 		if (val < 0) {
2270 			*negp = true;
2271 			*lvalp = (unsigned long)-val;
2272 		} else {
2273 			*negp = false;
2274 			*lvalp = (unsigned long)val;
2275 		}
2276 	}
2277 	return 0;
2278 }
2279 
2280 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2281 
2282 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2283 		  int write, void __user *buffer,
2284 		  size_t *lenp, loff_t *ppos,
2285 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2286 			      int write, void *data),
2287 		  void *data)
2288 {
2289 	int *i, vleft, first = 1, err = 0;
2290 	unsigned long page = 0;
2291 	size_t left;
2292 	char *kbuf;
2293 
2294 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2295 		*lenp = 0;
2296 		return 0;
2297 	}
2298 
2299 	i = (int *) tbl_data;
2300 	vleft = table->maxlen / sizeof(*i);
2301 	left = *lenp;
2302 
2303 	if (!conv)
2304 		conv = do_proc_dointvec_conv;
2305 
2306 	if (write) {
2307 		if (left > PAGE_SIZE - 1)
2308 			left = PAGE_SIZE - 1;
2309 		page = __get_free_page(GFP_TEMPORARY);
2310 		kbuf = (char *) page;
2311 		if (!kbuf)
2312 			return -ENOMEM;
2313 		if (copy_from_user(kbuf, buffer, left)) {
2314 			err = -EFAULT;
2315 			goto free;
2316 		}
2317 		kbuf[left] = 0;
2318 	}
2319 
2320 	for (; left && vleft--; i++, first=0) {
2321 		unsigned long lval;
2322 		bool neg;
2323 
2324 		if (write) {
2325 			left -= proc_skip_spaces(&kbuf);
2326 
2327 			if (!left)
2328 				break;
2329 			err = proc_get_long(&kbuf, &left, &lval, &neg,
2330 					     proc_wspace_sep,
2331 					     sizeof(proc_wspace_sep), NULL);
2332 			if (err)
2333 				break;
2334 			if (conv(&neg, &lval, i, 1, data)) {
2335 				err = -EINVAL;
2336 				break;
2337 			}
2338 		} else {
2339 			if (conv(&neg, &lval, i, 0, data)) {
2340 				err = -EINVAL;
2341 				break;
2342 			}
2343 			if (!first)
2344 				err = proc_put_char(&buffer, &left, '\t');
2345 			if (err)
2346 				break;
2347 			err = proc_put_long(&buffer, &left, lval, neg);
2348 			if (err)
2349 				break;
2350 		}
2351 	}
2352 
2353 	if (!write && !first && left && !err)
2354 		err = proc_put_char(&buffer, &left, '\n');
2355 	if (write && !err && left)
2356 		left -= proc_skip_spaces(&kbuf);
2357 free:
2358 	if (write) {
2359 		free_page(page);
2360 		if (first)
2361 			return err ? : -EINVAL;
2362 	}
2363 	*lenp -= left;
2364 	*ppos += *lenp;
2365 	return err;
2366 }
2367 
2368 static int do_proc_dointvec(struct ctl_table *table, int write,
2369 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2370 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2371 			      int write, void *data),
2372 		  void *data)
2373 {
2374 	return __do_proc_dointvec(table->data, table, write,
2375 			buffer, lenp, ppos, conv, data);
2376 }
2377 
2378 /**
2379  * proc_dointvec - read a vector of integers
2380  * @table: the sysctl table
2381  * @write: %TRUE if this is a write to the sysctl file
2382  * @buffer: the user buffer
2383  * @lenp: the size of the user buffer
2384  * @ppos: file position
2385  *
2386  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2387  * values from/to the user buffer, treated as an ASCII string.
2388  *
2389  * Returns 0 on success.
2390  */
2391 int proc_dointvec(struct ctl_table *table, int write,
2392 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2393 {
2394     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2395 		    	    NULL,NULL);
2396 }
2397 
2398 /*
2399  * Taint values can only be increased
2400  * This means we can safely use a temporary.
2401  */
2402 static int proc_taint(struct ctl_table *table, int write,
2403 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2404 {
2405 	struct ctl_table t;
2406 	unsigned long tmptaint = get_taint();
2407 	int err;
2408 
2409 	if (write && !capable(CAP_SYS_ADMIN))
2410 		return -EPERM;
2411 
2412 	t = *table;
2413 	t.data = &tmptaint;
2414 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2415 	if (err < 0)
2416 		return err;
2417 
2418 	if (write) {
2419 		/*
2420 		 * Poor man's atomic or. Not worth adding a primitive
2421 		 * to everyone's atomic.h for this
2422 		 */
2423 		int i;
2424 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2425 			if ((tmptaint >> i) & 1)
2426 				add_taint(i);
2427 		}
2428 	}
2429 
2430 	return err;
2431 }
2432 
2433 #ifdef CONFIG_PRINTK
2434 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2435 				void __user *buffer, size_t *lenp, loff_t *ppos)
2436 {
2437 	if (write && !capable(CAP_SYS_ADMIN))
2438 		return -EPERM;
2439 
2440 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2441 }
2442 #endif
2443 
2444 struct do_proc_dointvec_minmax_conv_param {
2445 	int *min;
2446 	int *max;
2447 };
2448 
2449 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2450 					int *valp,
2451 					int write, void *data)
2452 {
2453 	struct do_proc_dointvec_minmax_conv_param *param = data;
2454 	if (write) {
2455 		int val = *negp ? -*lvalp : *lvalp;
2456 		if ((param->min && *param->min > val) ||
2457 		    (param->max && *param->max < val))
2458 			return -EINVAL;
2459 		*valp = val;
2460 	} else {
2461 		int val = *valp;
2462 		if (val < 0) {
2463 			*negp = true;
2464 			*lvalp = (unsigned long)-val;
2465 		} else {
2466 			*negp = false;
2467 			*lvalp = (unsigned long)val;
2468 		}
2469 	}
2470 	return 0;
2471 }
2472 
2473 /**
2474  * proc_dointvec_minmax - read a vector of integers with min/max values
2475  * @table: the sysctl table
2476  * @write: %TRUE if this is a write to the sysctl file
2477  * @buffer: the user buffer
2478  * @lenp: the size of the user buffer
2479  * @ppos: file position
2480  *
2481  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2482  * values from/to the user buffer, treated as an ASCII string.
2483  *
2484  * This routine will ensure the values are within the range specified by
2485  * table->extra1 (min) and table->extra2 (max).
2486  *
2487  * Returns 0 on success.
2488  */
2489 int proc_dointvec_minmax(struct ctl_table *table, int write,
2490 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2491 {
2492 	struct do_proc_dointvec_minmax_conv_param param = {
2493 		.min = (int *) table->extra1,
2494 		.max = (int *) table->extra2,
2495 	};
2496 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2497 				do_proc_dointvec_minmax_conv, &param);
2498 }
2499 
2500 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2501 				     void __user *buffer,
2502 				     size_t *lenp, loff_t *ppos,
2503 				     unsigned long convmul,
2504 				     unsigned long convdiv)
2505 {
2506 	unsigned long *i, *min, *max;
2507 	int vleft, first = 1, err = 0;
2508 	unsigned long page = 0;
2509 	size_t left;
2510 	char *kbuf;
2511 
2512 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2513 		*lenp = 0;
2514 		return 0;
2515 	}
2516 
2517 	i = (unsigned long *) data;
2518 	min = (unsigned long *) table->extra1;
2519 	max = (unsigned long *) table->extra2;
2520 	vleft = table->maxlen / sizeof(unsigned long);
2521 	left = *lenp;
2522 
2523 	if (write) {
2524 		if (left > PAGE_SIZE - 1)
2525 			left = PAGE_SIZE - 1;
2526 		page = __get_free_page(GFP_TEMPORARY);
2527 		kbuf = (char *) page;
2528 		if (!kbuf)
2529 			return -ENOMEM;
2530 		if (copy_from_user(kbuf, buffer, left)) {
2531 			err = -EFAULT;
2532 			goto free;
2533 		}
2534 		kbuf[left] = 0;
2535 	}
2536 
2537 	for (; left && vleft--; i++, first = 0) {
2538 		unsigned long val;
2539 
2540 		if (write) {
2541 			bool neg;
2542 
2543 			left -= proc_skip_spaces(&kbuf);
2544 
2545 			err = proc_get_long(&kbuf, &left, &val, &neg,
2546 					     proc_wspace_sep,
2547 					     sizeof(proc_wspace_sep), NULL);
2548 			if (err)
2549 				break;
2550 			if (neg)
2551 				continue;
2552 			if ((min && val < *min) || (max && val > *max))
2553 				continue;
2554 			*i = val;
2555 		} else {
2556 			val = convdiv * (*i) / convmul;
2557 			if (!first)
2558 				err = proc_put_char(&buffer, &left, '\t');
2559 			err = proc_put_long(&buffer, &left, val, false);
2560 			if (err)
2561 				break;
2562 		}
2563 	}
2564 
2565 	if (!write && !first && left && !err)
2566 		err = proc_put_char(&buffer, &left, '\n');
2567 	if (write && !err)
2568 		left -= proc_skip_spaces(&kbuf);
2569 free:
2570 	if (write) {
2571 		free_page(page);
2572 		if (first)
2573 			return err ? : -EINVAL;
2574 	}
2575 	*lenp -= left;
2576 	*ppos += *lenp;
2577 	return err;
2578 }
2579 
2580 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2581 				     void __user *buffer,
2582 				     size_t *lenp, loff_t *ppos,
2583 				     unsigned long convmul,
2584 				     unsigned long convdiv)
2585 {
2586 	return __do_proc_doulongvec_minmax(table->data, table, write,
2587 			buffer, lenp, ppos, convmul, convdiv);
2588 }
2589 
2590 /**
2591  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2592  * @table: the sysctl table
2593  * @write: %TRUE if this is a write to the sysctl file
2594  * @buffer: the user buffer
2595  * @lenp: the size of the user buffer
2596  * @ppos: file position
2597  *
2598  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2599  * values from/to the user buffer, treated as an ASCII string.
2600  *
2601  * This routine will ensure the values are within the range specified by
2602  * table->extra1 (min) and table->extra2 (max).
2603  *
2604  * Returns 0 on success.
2605  */
2606 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2607 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2608 {
2609     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2610 }
2611 
2612 /**
2613  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2614  * @table: the sysctl table
2615  * @write: %TRUE if this is a write to the sysctl file
2616  * @buffer: the user buffer
2617  * @lenp: the size of the user buffer
2618  * @ppos: file position
2619  *
2620  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2621  * values from/to the user buffer, treated as an ASCII string. The values
2622  * are treated as milliseconds, and converted to jiffies when they are stored.
2623  *
2624  * This routine will ensure the values are within the range specified by
2625  * table->extra1 (min) and table->extra2 (max).
2626  *
2627  * Returns 0 on success.
2628  */
2629 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2630 				      void __user *buffer,
2631 				      size_t *lenp, loff_t *ppos)
2632 {
2633     return do_proc_doulongvec_minmax(table, write, buffer,
2634 				     lenp, ppos, HZ, 1000l);
2635 }
2636 
2637 
2638 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2639 					 int *valp,
2640 					 int write, void *data)
2641 {
2642 	if (write) {
2643 		if (*lvalp > LONG_MAX / HZ)
2644 			return 1;
2645 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2646 	} else {
2647 		int val = *valp;
2648 		unsigned long lval;
2649 		if (val < 0) {
2650 			*negp = true;
2651 			lval = (unsigned long)-val;
2652 		} else {
2653 			*negp = false;
2654 			lval = (unsigned long)val;
2655 		}
2656 		*lvalp = lval / HZ;
2657 	}
2658 	return 0;
2659 }
2660 
2661 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2662 						int *valp,
2663 						int write, void *data)
2664 {
2665 	if (write) {
2666 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2667 			return 1;
2668 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2669 	} else {
2670 		int val = *valp;
2671 		unsigned long lval;
2672 		if (val < 0) {
2673 			*negp = true;
2674 			lval = (unsigned long)-val;
2675 		} else {
2676 			*negp = false;
2677 			lval = (unsigned long)val;
2678 		}
2679 		*lvalp = jiffies_to_clock_t(lval);
2680 	}
2681 	return 0;
2682 }
2683 
2684 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2685 					    int *valp,
2686 					    int write, void *data)
2687 {
2688 	if (write) {
2689 		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2690 	} else {
2691 		int val = *valp;
2692 		unsigned long lval;
2693 		if (val < 0) {
2694 			*negp = true;
2695 			lval = (unsigned long)-val;
2696 		} else {
2697 			*negp = false;
2698 			lval = (unsigned long)val;
2699 		}
2700 		*lvalp = jiffies_to_msecs(lval);
2701 	}
2702 	return 0;
2703 }
2704 
2705 /**
2706  * proc_dointvec_jiffies - read a vector of integers as seconds
2707  * @table: the sysctl table
2708  * @write: %TRUE if this is a write to the sysctl file
2709  * @buffer: the user buffer
2710  * @lenp: the size of the user buffer
2711  * @ppos: file position
2712  *
2713  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2714  * values from/to the user buffer, treated as an ASCII string.
2715  * The values read are assumed to be in seconds, and are converted into
2716  * jiffies.
2717  *
2718  * Returns 0 on success.
2719  */
2720 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2721 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2722 {
2723     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2724 		    	    do_proc_dointvec_jiffies_conv,NULL);
2725 }
2726 
2727 /**
2728  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2729  * @table: the sysctl table
2730  * @write: %TRUE if this is a write to the sysctl file
2731  * @buffer: the user buffer
2732  * @lenp: the size of the user buffer
2733  * @ppos: pointer to the file position
2734  *
2735  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2736  * values from/to the user buffer, treated as an ASCII string.
2737  * The values read are assumed to be in 1/USER_HZ seconds, and
2738  * are converted into jiffies.
2739  *
2740  * Returns 0 on success.
2741  */
2742 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2743 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2744 {
2745     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2746 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2747 }
2748 
2749 /**
2750  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2751  * @table: the sysctl table
2752  * @write: %TRUE if this is a write to the sysctl file
2753  * @buffer: the user buffer
2754  * @lenp: the size of the user buffer
2755  * @ppos: file position
2756  * @ppos: the current position in the file
2757  *
2758  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2759  * values from/to the user buffer, treated as an ASCII string.
2760  * The values read are assumed to be in 1/1000 seconds, and
2761  * are converted into jiffies.
2762  *
2763  * Returns 0 on success.
2764  */
2765 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2766 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2767 {
2768 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2769 				do_proc_dointvec_ms_jiffies_conv, NULL);
2770 }
2771 
2772 static int proc_do_cad_pid(struct ctl_table *table, int write,
2773 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2774 {
2775 	struct pid *new_pid;
2776 	pid_t tmp;
2777 	int r;
2778 
2779 	tmp = pid_vnr(cad_pid);
2780 
2781 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2782 			       lenp, ppos, NULL, NULL);
2783 	if (r || !write)
2784 		return r;
2785 
2786 	new_pid = find_get_pid(tmp);
2787 	if (!new_pid)
2788 		return -ESRCH;
2789 
2790 	put_pid(xchg(&cad_pid, new_pid));
2791 	return 0;
2792 }
2793 
2794 /**
2795  * proc_do_large_bitmap - read/write from/to a large bitmap
2796  * @table: the sysctl table
2797  * @write: %TRUE if this is a write to the sysctl file
2798  * @buffer: the user buffer
2799  * @lenp: the size of the user buffer
2800  * @ppos: file position
2801  *
2802  * The bitmap is stored at table->data and the bitmap length (in bits)
2803  * in table->maxlen.
2804  *
2805  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2806  * large bitmaps may be represented in a compact manner. Writing into
2807  * the file will clear the bitmap then update it with the given input.
2808  *
2809  * Returns 0 on success.
2810  */
2811 int proc_do_large_bitmap(struct ctl_table *table, int write,
2812 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2813 {
2814 	int err = 0;
2815 	bool first = 1;
2816 	size_t left = *lenp;
2817 	unsigned long bitmap_len = table->maxlen;
2818 	unsigned long *bitmap = (unsigned long *) table->data;
2819 	unsigned long *tmp_bitmap = NULL;
2820 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2821 
2822 	if (!bitmap_len || !left || (*ppos && !write)) {
2823 		*lenp = 0;
2824 		return 0;
2825 	}
2826 
2827 	if (write) {
2828 		unsigned long page = 0;
2829 		char *kbuf;
2830 
2831 		if (left > PAGE_SIZE - 1)
2832 			left = PAGE_SIZE - 1;
2833 
2834 		page = __get_free_page(GFP_TEMPORARY);
2835 		kbuf = (char *) page;
2836 		if (!kbuf)
2837 			return -ENOMEM;
2838 		if (copy_from_user(kbuf, buffer, left)) {
2839 			free_page(page);
2840 			return -EFAULT;
2841                 }
2842 		kbuf[left] = 0;
2843 
2844 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2845 				     GFP_KERNEL);
2846 		if (!tmp_bitmap) {
2847 			free_page(page);
2848 			return -ENOMEM;
2849 		}
2850 		proc_skip_char(&kbuf, &left, '\n');
2851 		while (!err && left) {
2852 			unsigned long val_a, val_b;
2853 			bool neg;
2854 
2855 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2856 					     sizeof(tr_a), &c);
2857 			if (err)
2858 				break;
2859 			if (val_a >= bitmap_len || neg) {
2860 				err = -EINVAL;
2861 				break;
2862 			}
2863 
2864 			val_b = val_a;
2865 			if (left) {
2866 				kbuf++;
2867 				left--;
2868 			}
2869 
2870 			if (c == '-') {
2871 				err = proc_get_long(&kbuf, &left, &val_b,
2872 						     &neg, tr_b, sizeof(tr_b),
2873 						     &c);
2874 				if (err)
2875 					break;
2876 				if (val_b >= bitmap_len || neg ||
2877 				    val_a > val_b) {
2878 					err = -EINVAL;
2879 					break;
2880 				}
2881 				if (left) {
2882 					kbuf++;
2883 					left--;
2884 				}
2885 			}
2886 
2887 			while (val_a <= val_b)
2888 				set_bit(val_a++, tmp_bitmap);
2889 
2890 			first = 0;
2891 			proc_skip_char(&kbuf, &left, '\n');
2892 		}
2893 		free_page(page);
2894 	} else {
2895 		unsigned long bit_a, bit_b = 0;
2896 
2897 		while (left) {
2898 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2899 			if (bit_a >= bitmap_len)
2900 				break;
2901 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2902 						   bit_a + 1) - 1;
2903 
2904 			if (!first) {
2905 				err = proc_put_char(&buffer, &left, ',');
2906 				if (err)
2907 					break;
2908 			}
2909 			err = proc_put_long(&buffer, &left, bit_a, false);
2910 			if (err)
2911 				break;
2912 			if (bit_a != bit_b) {
2913 				err = proc_put_char(&buffer, &left, '-');
2914 				if (err)
2915 					break;
2916 				err = proc_put_long(&buffer, &left, bit_b, false);
2917 				if (err)
2918 					break;
2919 			}
2920 
2921 			first = 0; bit_b++;
2922 		}
2923 		if (!err)
2924 			err = proc_put_char(&buffer, &left, '\n');
2925 	}
2926 
2927 	if (!err) {
2928 		if (write) {
2929 			if (*ppos)
2930 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2931 			else
2932 				memcpy(bitmap, tmp_bitmap,
2933 					BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2934 		}
2935 		kfree(tmp_bitmap);
2936 		*lenp -= left;
2937 		*ppos += *lenp;
2938 		return 0;
2939 	} else {
2940 		kfree(tmp_bitmap);
2941 		return err;
2942 	}
2943 }
2944 
2945 #else /* CONFIG_PROC_SYSCTL */
2946 
2947 int proc_dostring(struct ctl_table *table, int write,
2948 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2949 {
2950 	return -ENOSYS;
2951 }
2952 
2953 int proc_dointvec(struct ctl_table *table, int write,
2954 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2955 {
2956 	return -ENOSYS;
2957 }
2958 
2959 int proc_dointvec_minmax(struct ctl_table *table, int write,
2960 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2961 {
2962 	return -ENOSYS;
2963 }
2964 
2965 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2966 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2967 {
2968 	return -ENOSYS;
2969 }
2970 
2971 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2972 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2973 {
2974 	return -ENOSYS;
2975 }
2976 
2977 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2978 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2979 {
2980 	return -ENOSYS;
2981 }
2982 
2983 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2984 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2985 {
2986 	return -ENOSYS;
2987 }
2988 
2989 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2990 				      void __user *buffer,
2991 				      size_t *lenp, loff_t *ppos)
2992 {
2993     return -ENOSYS;
2994 }
2995 
2996 
2997 #endif /* CONFIG_PROC_SYSCTL */
2998 
2999 /*
3000  * No sense putting this after each symbol definition, twice,
3001  * exception granted :-)
3002  */
3003 EXPORT_SYMBOL(proc_dointvec);
3004 EXPORT_SYMBOL(proc_dointvec_jiffies);
3005 EXPORT_SYMBOL(proc_dointvec_minmax);
3006 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3007 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3008 EXPORT_SYMBOL(proc_dostring);
3009 EXPORT_SYMBOL(proc_doulongvec_minmax);
3010 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3011 EXPORT_SYMBOL(register_sysctl_table);
3012 EXPORT_SYMBOL(register_sysctl_paths);
3013 EXPORT_SYMBOL(unregister_sysctl_table);
3014