xref: /linux/kernel/sysctl.c (revision 8ec3b8432e4fe8d452f88f1ed9a3450e715bb797)
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 
60 #include <asm/uaccess.h>
61 #include <asm/processor.h>
62 
63 #ifdef CONFIG_X86
64 #include <asm/nmi.h>
65 #include <asm/stacktrace.h>
66 #include <asm/io.h>
67 #endif
68 #ifdef CONFIG_BSD_PROCESS_ACCT
69 #include <linux/acct.h>
70 #endif
71 #ifdef CONFIG_RT_MUTEXES
72 #include <linux/rtmutex.h>
73 #endif
74 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
75 #include <linux/lockdep.h>
76 #endif
77 #ifdef CONFIG_CHR_DEV_SG
78 #include <scsi/sg.h>
79 #endif
80 
81 #ifdef CONFIG_LOCKUP_DETECTOR
82 #include <linux/nmi.h>
83 #endif
84 
85 
86 #if defined(CONFIG_SYSCTL)
87 
88 /* External variables not in a header file. */
89 extern int sysctl_overcommit_memory;
90 extern int sysctl_overcommit_ratio;
91 extern int max_threads;
92 extern int core_uses_pid;
93 extern int suid_dumpable;
94 extern char core_pattern[];
95 extern unsigned int core_pipe_limit;
96 extern int pid_max;
97 extern int min_free_kbytes;
98 extern int pid_max_min, pid_max_max;
99 extern int sysctl_drop_caches;
100 extern int percpu_pagelist_fraction;
101 extern int compat_log;
102 extern int latencytop_enabled;
103 extern int sysctl_nr_open_min, sysctl_nr_open_max;
104 #ifndef CONFIG_MMU
105 extern int sysctl_nr_trim_pages;
106 #endif
107 #ifdef CONFIG_BLOCK
108 extern int blk_iopoll_enabled;
109 #endif
110 
111 /* Constants used for minimum and  maximum */
112 #ifdef CONFIG_LOCKUP_DETECTOR
113 static int sixty = 60;
114 static int neg_one = -1;
115 #endif
116 
117 static int zero;
118 static int __maybe_unused one = 1;
119 static int __maybe_unused two = 2;
120 static unsigned long one_ul = 1;
121 static int one_hundred = 100;
122 #ifdef CONFIG_PRINTK
123 static int ten_thousand = 10000;
124 #endif
125 
126 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
127 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
128 
129 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
130 static int maxolduid = 65535;
131 static int minolduid;
132 static int min_percpu_pagelist_fract = 8;
133 
134 static int ngroups_max = NGROUPS_MAX;
135 
136 #ifdef CONFIG_INOTIFY_USER
137 #include <linux/inotify.h>
138 #endif
139 #ifdef CONFIG_SPARC
140 #include <asm/system.h>
141 #endif
142 
143 #ifdef CONFIG_SPARC64
144 extern int sysctl_tsb_ratio;
145 #endif
146 
147 #ifdef __hppa__
148 extern int pwrsw_enabled;
149 extern int unaligned_enabled;
150 #endif
151 
152 #ifdef CONFIG_S390
153 #ifdef CONFIG_MATHEMU
154 extern int sysctl_ieee_emulation_warnings;
155 #endif
156 extern int sysctl_userprocess_debug;
157 extern int spin_retry;
158 #endif
159 
160 #ifdef CONFIG_IA64
161 extern int no_unaligned_warning;
162 extern int unaligned_dump_stack;
163 #endif
164 
165 #ifdef CONFIG_PROC_SYSCTL
166 static int proc_do_cad_pid(struct ctl_table *table, int write,
167 		  void __user *buffer, size_t *lenp, loff_t *ppos);
168 static int proc_taint(struct ctl_table *table, int write,
169 			       void __user *buffer, size_t *lenp, loff_t *ppos);
170 #endif
171 
172 #ifdef CONFIG_MAGIC_SYSRQ
173 /* Note: sysrq code uses it's own private copy */
174 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
175 
176 static int sysrq_sysctl_handler(ctl_table *table, int write,
177 				void __user *buffer, size_t *lenp,
178 				loff_t *ppos)
179 {
180 	int error;
181 
182 	error = proc_dointvec(table, write, buffer, lenp, ppos);
183 	if (error)
184 		return error;
185 
186 	if (write)
187 		sysrq_toggle_support(__sysrq_enabled);
188 
189 	return 0;
190 }
191 
192 #endif
193 
194 static struct ctl_table root_table[];
195 static struct ctl_table_root sysctl_table_root;
196 static struct ctl_table_header root_table_header = {
197 	{{.count = 1,
198 	.ctl_table = root_table,
199 	.ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
200 	.root = &sysctl_table_root,
201 	.set = &sysctl_table_root.default_set,
202 };
203 static struct ctl_table_root sysctl_table_root = {
204 	.root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
205 	.default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
206 };
207 
208 static struct ctl_table kern_table[];
209 static struct ctl_table vm_table[];
210 static struct ctl_table fs_table[];
211 static struct ctl_table debug_table[];
212 static struct ctl_table dev_table[];
213 extern struct ctl_table random_table[];
214 #ifdef CONFIG_EPOLL
215 extern struct ctl_table epoll_table[];
216 #endif
217 
218 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
219 int sysctl_legacy_va_layout;
220 #endif
221 
222 /* The default sysctl tables: */
223 
224 static struct ctl_table root_table[] = {
225 	{
226 		.procname	= "kernel",
227 		.mode		= 0555,
228 		.child		= kern_table,
229 	},
230 	{
231 		.procname	= "vm",
232 		.mode		= 0555,
233 		.child		= vm_table,
234 	},
235 	{
236 		.procname	= "fs",
237 		.mode		= 0555,
238 		.child		= fs_table,
239 	},
240 	{
241 		.procname	= "debug",
242 		.mode		= 0555,
243 		.child		= debug_table,
244 	},
245 	{
246 		.procname	= "dev",
247 		.mode		= 0555,
248 		.child		= dev_table,
249 	},
250 	{ }
251 };
252 
253 #ifdef CONFIG_SCHED_DEBUG
254 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
255 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
256 static int min_wakeup_granularity_ns;			/* 0 usecs */
257 static int max_wakeup_granularity_ns = NSEC_PER_SEC;	/* 1 second */
258 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
259 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
260 #endif
261 
262 #ifdef CONFIG_COMPACTION
263 static int min_extfrag_threshold;
264 static int max_extfrag_threshold = 1000;
265 #endif
266 
267 static struct ctl_table kern_table[] = {
268 	{
269 		.procname	= "sched_child_runs_first",
270 		.data		= &sysctl_sched_child_runs_first,
271 		.maxlen		= sizeof(unsigned int),
272 		.mode		= 0644,
273 		.proc_handler	= proc_dointvec,
274 	},
275 #ifdef CONFIG_SCHED_DEBUG
276 	{
277 		.procname	= "sched_min_granularity_ns",
278 		.data		= &sysctl_sched_min_granularity,
279 		.maxlen		= sizeof(unsigned int),
280 		.mode		= 0644,
281 		.proc_handler	= sched_proc_update_handler,
282 		.extra1		= &min_sched_granularity_ns,
283 		.extra2		= &max_sched_granularity_ns,
284 	},
285 	{
286 		.procname	= "sched_latency_ns",
287 		.data		= &sysctl_sched_latency,
288 		.maxlen		= sizeof(unsigned int),
289 		.mode		= 0644,
290 		.proc_handler	= sched_proc_update_handler,
291 		.extra1		= &min_sched_granularity_ns,
292 		.extra2		= &max_sched_granularity_ns,
293 	},
294 	{
295 		.procname	= "sched_wakeup_granularity_ns",
296 		.data		= &sysctl_sched_wakeup_granularity,
297 		.maxlen		= sizeof(unsigned int),
298 		.mode		= 0644,
299 		.proc_handler	= sched_proc_update_handler,
300 		.extra1		= &min_wakeup_granularity_ns,
301 		.extra2		= &max_wakeup_granularity_ns,
302 	},
303 	{
304 		.procname	= "sched_tunable_scaling",
305 		.data		= &sysctl_sched_tunable_scaling,
306 		.maxlen		= sizeof(enum sched_tunable_scaling),
307 		.mode		= 0644,
308 		.proc_handler	= sched_proc_update_handler,
309 		.extra1		= &min_sched_tunable_scaling,
310 		.extra2		= &max_sched_tunable_scaling,
311 	},
312 	{
313 		.procname	= "sched_migration_cost",
314 		.data		= &sysctl_sched_migration_cost,
315 		.maxlen		= sizeof(unsigned int),
316 		.mode		= 0644,
317 		.proc_handler	= proc_dointvec,
318 	},
319 	{
320 		.procname	= "sched_nr_migrate",
321 		.data		= &sysctl_sched_nr_migrate,
322 		.maxlen		= sizeof(unsigned int),
323 		.mode		= 0644,
324 		.proc_handler	= proc_dointvec,
325 	},
326 	{
327 		.procname	= "sched_time_avg",
328 		.data		= &sysctl_sched_time_avg,
329 		.maxlen		= sizeof(unsigned int),
330 		.mode		= 0644,
331 		.proc_handler	= proc_dointvec,
332 	},
333 	{
334 		.procname	= "sched_shares_window",
335 		.data		= &sysctl_sched_shares_window,
336 		.maxlen		= sizeof(unsigned int),
337 		.mode		= 0644,
338 		.proc_handler	= proc_dointvec,
339 	},
340 	{
341 		.procname	= "timer_migration",
342 		.data		= &sysctl_timer_migration,
343 		.maxlen		= sizeof(unsigned int),
344 		.mode		= 0644,
345 		.proc_handler	= proc_dointvec_minmax,
346 		.extra1		= &zero,
347 		.extra2		= &one,
348 	},
349 #endif
350 	{
351 		.procname	= "sched_rt_period_us",
352 		.data		= &sysctl_sched_rt_period,
353 		.maxlen		= sizeof(unsigned int),
354 		.mode		= 0644,
355 		.proc_handler	= sched_rt_handler,
356 	},
357 	{
358 		.procname	= "sched_rt_runtime_us",
359 		.data		= &sysctl_sched_rt_runtime,
360 		.maxlen		= sizeof(int),
361 		.mode		= 0644,
362 		.proc_handler	= sched_rt_handler,
363 	},
364 	{
365 		.procname	= "sched_compat_yield",
366 		.data		= &sysctl_sched_compat_yield,
367 		.maxlen		= sizeof(unsigned int),
368 		.mode		= 0644,
369 		.proc_handler	= proc_dointvec,
370 	},
371 #ifdef CONFIG_SCHED_AUTOGROUP
372 	{
373 		.procname	= "sched_autogroup_enabled",
374 		.data		= &sysctl_sched_autogroup_enabled,
375 		.maxlen		= sizeof(unsigned int),
376 		.mode		= 0644,
377 		.proc_handler	= proc_dointvec,
378 		.extra1		= &zero,
379 		.extra2		= &one,
380 	},
381 #endif
382 #ifdef CONFIG_PROVE_LOCKING
383 	{
384 		.procname	= "prove_locking",
385 		.data		= &prove_locking,
386 		.maxlen		= sizeof(int),
387 		.mode		= 0644,
388 		.proc_handler	= proc_dointvec,
389 	},
390 #endif
391 #ifdef CONFIG_LOCK_STAT
392 	{
393 		.procname	= "lock_stat",
394 		.data		= &lock_stat,
395 		.maxlen		= sizeof(int),
396 		.mode		= 0644,
397 		.proc_handler	= proc_dointvec,
398 	},
399 #endif
400 	{
401 		.procname	= "panic",
402 		.data		= &panic_timeout,
403 		.maxlen		= sizeof(int),
404 		.mode		= 0644,
405 		.proc_handler	= proc_dointvec,
406 	},
407 	{
408 		.procname	= "core_uses_pid",
409 		.data		= &core_uses_pid,
410 		.maxlen		= sizeof(int),
411 		.mode		= 0644,
412 		.proc_handler	= proc_dointvec,
413 	},
414 	{
415 		.procname	= "core_pattern",
416 		.data		= core_pattern,
417 		.maxlen		= CORENAME_MAX_SIZE,
418 		.mode		= 0644,
419 		.proc_handler	= proc_dostring,
420 	},
421 	{
422 		.procname	= "core_pipe_limit",
423 		.data		= &core_pipe_limit,
424 		.maxlen		= sizeof(unsigned int),
425 		.mode		= 0644,
426 		.proc_handler	= proc_dointvec,
427 	},
428 #ifdef CONFIG_PROC_SYSCTL
429 	{
430 		.procname	= "tainted",
431 		.maxlen 	= sizeof(long),
432 		.mode		= 0644,
433 		.proc_handler	= proc_taint,
434 	},
435 #endif
436 #ifdef CONFIG_LATENCYTOP
437 	{
438 		.procname	= "latencytop",
439 		.data		= &latencytop_enabled,
440 		.maxlen		= sizeof(int),
441 		.mode		= 0644,
442 		.proc_handler	= proc_dointvec,
443 	},
444 #endif
445 #ifdef CONFIG_BLK_DEV_INITRD
446 	{
447 		.procname	= "real-root-dev",
448 		.data		= &real_root_dev,
449 		.maxlen		= sizeof(int),
450 		.mode		= 0644,
451 		.proc_handler	= proc_dointvec,
452 	},
453 #endif
454 	{
455 		.procname	= "print-fatal-signals",
456 		.data		= &print_fatal_signals,
457 		.maxlen		= sizeof(int),
458 		.mode		= 0644,
459 		.proc_handler	= proc_dointvec,
460 	},
461 #ifdef CONFIG_SPARC
462 	{
463 		.procname	= "reboot-cmd",
464 		.data		= reboot_command,
465 		.maxlen		= 256,
466 		.mode		= 0644,
467 		.proc_handler	= proc_dostring,
468 	},
469 	{
470 		.procname	= "stop-a",
471 		.data		= &stop_a_enabled,
472 		.maxlen		= sizeof (int),
473 		.mode		= 0644,
474 		.proc_handler	= proc_dointvec,
475 	},
476 	{
477 		.procname	= "scons-poweroff",
478 		.data		= &scons_pwroff,
479 		.maxlen		= sizeof (int),
480 		.mode		= 0644,
481 		.proc_handler	= proc_dointvec,
482 	},
483 #endif
484 #ifdef CONFIG_SPARC64
485 	{
486 		.procname	= "tsb-ratio",
487 		.data		= &sysctl_tsb_ratio,
488 		.maxlen		= sizeof (int),
489 		.mode		= 0644,
490 		.proc_handler	= proc_dointvec,
491 	},
492 #endif
493 #ifdef __hppa__
494 	{
495 		.procname	= "soft-power",
496 		.data		= &pwrsw_enabled,
497 		.maxlen		= sizeof (int),
498 	 	.mode		= 0644,
499 		.proc_handler	= proc_dointvec,
500 	},
501 	{
502 		.procname	= "unaligned-trap",
503 		.data		= &unaligned_enabled,
504 		.maxlen		= sizeof (int),
505 		.mode		= 0644,
506 		.proc_handler	= proc_dointvec,
507 	},
508 #endif
509 	{
510 		.procname	= "ctrl-alt-del",
511 		.data		= &C_A_D,
512 		.maxlen		= sizeof(int),
513 		.mode		= 0644,
514 		.proc_handler	= proc_dointvec,
515 	},
516 #ifdef CONFIG_FUNCTION_TRACER
517 	{
518 		.procname	= "ftrace_enabled",
519 		.data		= &ftrace_enabled,
520 		.maxlen		= sizeof(int),
521 		.mode		= 0644,
522 		.proc_handler	= ftrace_enable_sysctl,
523 	},
524 #endif
525 #ifdef CONFIG_STACK_TRACER
526 	{
527 		.procname	= "stack_tracer_enabled",
528 		.data		= &stack_tracer_enabled,
529 		.maxlen		= sizeof(int),
530 		.mode		= 0644,
531 		.proc_handler	= stack_trace_sysctl,
532 	},
533 #endif
534 #ifdef CONFIG_TRACING
535 	{
536 		.procname	= "ftrace_dump_on_oops",
537 		.data		= &ftrace_dump_on_oops,
538 		.maxlen		= sizeof(int),
539 		.mode		= 0644,
540 		.proc_handler	= proc_dointvec,
541 	},
542 #endif
543 #ifdef CONFIG_MODULES
544 	{
545 		.procname	= "modprobe",
546 		.data		= &modprobe_path,
547 		.maxlen		= KMOD_PATH_LEN,
548 		.mode		= 0644,
549 		.proc_handler	= proc_dostring,
550 	},
551 	{
552 		.procname	= "modules_disabled",
553 		.data		= &modules_disabled,
554 		.maxlen		= sizeof(int),
555 		.mode		= 0644,
556 		/* only handle a transition from default "0" to "1" */
557 		.proc_handler	= proc_dointvec_minmax,
558 		.extra1		= &one,
559 		.extra2		= &one,
560 	},
561 #endif
562 #ifdef CONFIG_HOTPLUG
563 	{
564 		.procname	= "hotplug",
565 		.data		= &uevent_helper,
566 		.maxlen		= UEVENT_HELPER_PATH_LEN,
567 		.mode		= 0644,
568 		.proc_handler	= proc_dostring,
569 	},
570 #endif
571 #ifdef CONFIG_CHR_DEV_SG
572 	{
573 		.procname	= "sg-big-buff",
574 		.data		= &sg_big_buff,
575 		.maxlen		= sizeof (int),
576 		.mode		= 0444,
577 		.proc_handler	= proc_dointvec,
578 	},
579 #endif
580 #ifdef CONFIG_BSD_PROCESS_ACCT
581 	{
582 		.procname	= "acct",
583 		.data		= &acct_parm,
584 		.maxlen		= 3*sizeof(int),
585 		.mode		= 0644,
586 		.proc_handler	= proc_dointvec,
587 	},
588 #endif
589 #ifdef CONFIG_MAGIC_SYSRQ
590 	{
591 		.procname	= "sysrq",
592 		.data		= &__sysrq_enabled,
593 		.maxlen		= sizeof (int),
594 		.mode		= 0644,
595 		.proc_handler	= sysrq_sysctl_handler,
596 	},
597 #endif
598 #ifdef CONFIG_PROC_SYSCTL
599 	{
600 		.procname	= "cad_pid",
601 		.data		= NULL,
602 		.maxlen		= sizeof (int),
603 		.mode		= 0600,
604 		.proc_handler	= proc_do_cad_pid,
605 	},
606 #endif
607 	{
608 		.procname	= "threads-max",
609 		.data		= &max_threads,
610 		.maxlen		= sizeof(int),
611 		.mode		= 0644,
612 		.proc_handler	= proc_dointvec,
613 	},
614 	{
615 		.procname	= "random",
616 		.mode		= 0555,
617 		.child		= random_table,
618 	},
619 	{
620 		.procname	= "overflowuid",
621 		.data		= &overflowuid,
622 		.maxlen		= sizeof(int),
623 		.mode		= 0644,
624 		.proc_handler	= proc_dointvec_minmax,
625 		.extra1		= &minolduid,
626 		.extra2		= &maxolduid,
627 	},
628 	{
629 		.procname	= "overflowgid",
630 		.data		= &overflowgid,
631 		.maxlen		= sizeof(int),
632 		.mode		= 0644,
633 		.proc_handler	= proc_dointvec_minmax,
634 		.extra1		= &minolduid,
635 		.extra2		= &maxolduid,
636 	},
637 #ifdef CONFIG_S390
638 #ifdef CONFIG_MATHEMU
639 	{
640 		.procname	= "ieee_emulation_warnings",
641 		.data		= &sysctl_ieee_emulation_warnings,
642 		.maxlen		= sizeof(int),
643 		.mode		= 0644,
644 		.proc_handler	= proc_dointvec,
645 	},
646 #endif
647 	{
648 		.procname	= "userprocess_debug",
649 		.data		= &show_unhandled_signals,
650 		.maxlen		= sizeof(int),
651 		.mode		= 0644,
652 		.proc_handler	= proc_dointvec,
653 	},
654 #endif
655 	{
656 		.procname	= "pid_max",
657 		.data		= &pid_max,
658 		.maxlen		= sizeof (int),
659 		.mode		= 0644,
660 		.proc_handler	= proc_dointvec_minmax,
661 		.extra1		= &pid_max_min,
662 		.extra2		= &pid_max_max,
663 	},
664 	{
665 		.procname	= "panic_on_oops",
666 		.data		= &panic_on_oops,
667 		.maxlen		= sizeof(int),
668 		.mode		= 0644,
669 		.proc_handler	= proc_dointvec,
670 	},
671 #if defined CONFIG_PRINTK
672 	{
673 		.procname	= "printk",
674 		.data		= &console_loglevel,
675 		.maxlen		= 4*sizeof(int),
676 		.mode		= 0644,
677 		.proc_handler	= proc_dointvec,
678 	},
679 	{
680 		.procname	= "printk_ratelimit",
681 		.data		= &printk_ratelimit_state.interval,
682 		.maxlen		= sizeof(int),
683 		.mode		= 0644,
684 		.proc_handler	= proc_dointvec_jiffies,
685 	},
686 	{
687 		.procname	= "printk_ratelimit_burst",
688 		.data		= &printk_ratelimit_state.burst,
689 		.maxlen		= sizeof(int),
690 		.mode		= 0644,
691 		.proc_handler	= proc_dointvec,
692 	},
693 	{
694 		.procname	= "printk_delay",
695 		.data		= &printk_delay_msec,
696 		.maxlen		= sizeof(int),
697 		.mode		= 0644,
698 		.proc_handler	= proc_dointvec_minmax,
699 		.extra1		= &zero,
700 		.extra2		= &ten_thousand,
701 	},
702 	{
703 		.procname	= "dmesg_restrict",
704 		.data		= &dmesg_restrict,
705 		.maxlen		= sizeof(int),
706 		.mode		= 0644,
707 		.proc_handler	= proc_dointvec_minmax,
708 		.extra1		= &zero,
709 		.extra2		= &one,
710 	},
711 	{
712 		.procname	= "kptr_restrict",
713 		.data		= &kptr_restrict,
714 		.maxlen		= sizeof(int),
715 		.mode		= 0644,
716 		.proc_handler	= proc_dointvec_minmax,
717 		.extra1		= &zero,
718 		.extra2		= &two,
719 	},
720 #endif
721 	{
722 		.procname	= "ngroups_max",
723 		.data		= &ngroups_max,
724 		.maxlen		= sizeof (int),
725 		.mode		= 0444,
726 		.proc_handler	= proc_dointvec,
727 	},
728 #if defined(CONFIG_LOCKUP_DETECTOR)
729 	{
730 		.procname       = "watchdog",
731 		.data           = &watchdog_enabled,
732 		.maxlen         = sizeof (int),
733 		.mode           = 0644,
734 		.proc_handler   = proc_dowatchdog_enabled,
735 	},
736 	{
737 		.procname	= "watchdog_thresh",
738 		.data		= &softlockup_thresh,
739 		.maxlen		= sizeof(int),
740 		.mode		= 0644,
741 		.proc_handler	= proc_dowatchdog_thresh,
742 		.extra1		= &neg_one,
743 		.extra2		= &sixty,
744 	},
745 	{
746 		.procname	= "softlockup_panic",
747 		.data		= &softlockup_panic,
748 		.maxlen		= sizeof(int),
749 		.mode		= 0644,
750 		.proc_handler	= proc_dointvec_minmax,
751 		.extra1		= &zero,
752 		.extra2		= &one,
753 	},
754 	{
755 		.procname       = "nmi_watchdog",
756 		.data           = &watchdog_enabled,
757 		.maxlen         = sizeof (int),
758 		.mode           = 0644,
759 		.proc_handler   = proc_dowatchdog_enabled,
760 	},
761 #endif
762 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
763 	{
764 		.procname       = "unknown_nmi_panic",
765 		.data           = &unknown_nmi_panic,
766 		.maxlen         = sizeof (int),
767 		.mode           = 0644,
768 		.proc_handler   = proc_dointvec,
769 	},
770 #endif
771 #if defined(CONFIG_X86)
772 	{
773 		.procname	= "panic_on_unrecovered_nmi",
774 		.data		= &panic_on_unrecovered_nmi,
775 		.maxlen		= sizeof(int),
776 		.mode		= 0644,
777 		.proc_handler	= proc_dointvec,
778 	},
779 	{
780 		.procname	= "panic_on_io_nmi",
781 		.data		= &panic_on_io_nmi,
782 		.maxlen		= sizeof(int),
783 		.mode		= 0644,
784 		.proc_handler	= proc_dointvec,
785 	},
786 	{
787 		.procname	= "bootloader_type",
788 		.data		= &bootloader_type,
789 		.maxlen		= sizeof (int),
790 		.mode		= 0444,
791 		.proc_handler	= proc_dointvec,
792 	},
793 	{
794 		.procname	= "bootloader_version",
795 		.data		= &bootloader_version,
796 		.maxlen		= sizeof (int),
797 		.mode		= 0444,
798 		.proc_handler	= proc_dointvec,
799 	},
800 	{
801 		.procname	= "kstack_depth_to_print",
802 		.data		= &kstack_depth_to_print,
803 		.maxlen		= sizeof(int),
804 		.mode		= 0644,
805 		.proc_handler	= proc_dointvec,
806 	},
807 	{
808 		.procname	= "io_delay_type",
809 		.data		= &io_delay_type,
810 		.maxlen		= sizeof(int),
811 		.mode		= 0644,
812 		.proc_handler	= proc_dointvec,
813 	},
814 #endif
815 #if defined(CONFIG_MMU)
816 	{
817 		.procname	= "randomize_va_space",
818 		.data		= &randomize_va_space,
819 		.maxlen		= sizeof(int),
820 		.mode		= 0644,
821 		.proc_handler	= proc_dointvec,
822 	},
823 #endif
824 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
825 	{
826 		.procname	= "spin_retry",
827 		.data		= &spin_retry,
828 		.maxlen		= sizeof (int),
829 		.mode		= 0644,
830 		.proc_handler	= proc_dointvec,
831 	},
832 #endif
833 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
834 	{
835 		.procname	= "acpi_video_flags",
836 		.data		= &acpi_realmode_flags,
837 		.maxlen		= sizeof (unsigned long),
838 		.mode		= 0644,
839 		.proc_handler	= proc_doulongvec_minmax,
840 	},
841 #endif
842 #ifdef CONFIG_IA64
843 	{
844 		.procname	= "ignore-unaligned-usertrap",
845 		.data		= &no_unaligned_warning,
846 		.maxlen		= sizeof (int),
847 	 	.mode		= 0644,
848 		.proc_handler	= proc_dointvec,
849 	},
850 	{
851 		.procname	= "unaligned-dump-stack",
852 		.data		= &unaligned_dump_stack,
853 		.maxlen		= sizeof (int),
854 		.mode		= 0644,
855 		.proc_handler	= proc_dointvec,
856 	},
857 #endif
858 #ifdef CONFIG_DETECT_HUNG_TASK
859 	{
860 		.procname	= "hung_task_panic",
861 		.data		= &sysctl_hung_task_panic,
862 		.maxlen		= sizeof(int),
863 		.mode		= 0644,
864 		.proc_handler	= proc_dointvec_minmax,
865 		.extra1		= &zero,
866 		.extra2		= &one,
867 	},
868 	{
869 		.procname	= "hung_task_check_count",
870 		.data		= &sysctl_hung_task_check_count,
871 		.maxlen		= sizeof(unsigned long),
872 		.mode		= 0644,
873 		.proc_handler	= proc_doulongvec_minmax,
874 	},
875 	{
876 		.procname	= "hung_task_timeout_secs",
877 		.data		= &sysctl_hung_task_timeout_secs,
878 		.maxlen		= sizeof(unsigned long),
879 		.mode		= 0644,
880 		.proc_handler	= proc_dohung_task_timeout_secs,
881 	},
882 	{
883 		.procname	= "hung_task_warnings",
884 		.data		= &sysctl_hung_task_warnings,
885 		.maxlen		= sizeof(unsigned long),
886 		.mode		= 0644,
887 		.proc_handler	= proc_doulongvec_minmax,
888 	},
889 #endif
890 #ifdef CONFIG_COMPAT
891 	{
892 		.procname	= "compat-log",
893 		.data		= &compat_log,
894 		.maxlen		= sizeof (int),
895 	 	.mode		= 0644,
896 		.proc_handler	= proc_dointvec,
897 	},
898 #endif
899 #ifdef CONFIG_RT_MUTEXES
900 	{
901 		.procname	= "max_lock_depth",
902 		.data		= &max_lock_depth,
903 		.maxlen		= sizeof(int),
904 		.mode		= 0644,
905 		.proc_handler	= proc_dointvec,
906 	},
907 #endif
908 	{
909 		.procname	= "poweroff_cmd",
910 		.data		= &poweroff_cmd,
911 		.maxlen		= POWEROFF_CMD_PATH_LEN,
912 		.mode		= 0644,
913 		.proc_handler	= proc_dostring,
914 	},
915 #ifdef CONFIG_KEYS
916 	{
917 		.procname	= "keys",
918 		.mode		= 0555,
919 		.child		= key_sysctls,
920 	},
921 #endif
922 #ifdef CONFIG_RCU_TORTURE_TEST
923 	{
924 		.procname       = "rcutorture_runnable",
925 		.data           = &rcutorture_runnable,
926 		.maxlen         = sizeof(int),
927 		.mode           = 0644,
928 		.proc_handler	= proc_dointvec,
929 	},
930 #endif
931 #ifdef CONFIG_PERF_EVENTS
932 	{
933 		.procname	= "perf_event_paranoid",
934 		.data		= &sysctl_perf_event_paranoid,
935 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
936 		.mode		= 0644,
937 		.proc_handler	= proc_dointvec,
938 	},
939 	{
940 		.procname	= "perf_event_mlock_kb",
941 		.data		= &sysctl_perf_event_mlock,
942 		.maxlen		= sizeof(sysctl_perf_event_mlock),
943 		.mode		= 0644,
944 		.proc_handler	= proc_dointvec,
945 	},
946 	{
947 		.procname	= "perf_event_max_sample_rate",
948 		.data		= &sysctl_perf_event_sample_rate,
949 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
950 		.mode		= 0644,
951 		.proc_handler	= proc_dointvec,
952 	},
953 #endif
954 #ifdef CONFIG_KMEMCHECK
955 	{
956 		.procname	= "kmemcheck",
957 		.data		= &kmemcheck_enabled,
958 		.maxlen		= sizeof(int),
959 		.mode		= 0644,
960 		.proc_handler	= proc_dointvec,
961 	},
962 #endif
963 #ifdef CONFIG_BLOCK
964 	{
965 		.procname	= "blk_iopoll",
966 		.data		= &blk_iopoll_enabled,
967 		.maxlen		= sizeof(int),
968 		.mode		= 0644,
969 		.proc_handler	= proc_dointvec,
970 	},
971 #endif
972 	{ }
973 };
974 
975 static struct ctl_table vm_table[] = {
976 	{
977 		.procname	= "overcommit_memory",
978 		.data		= &sysctl_overcommit_memory,
979 		.maxlen		= sizeof(sysctl_overcommit_memory),
980 		.mode		= 0644,
981 		.proc_handler	= proc_dointvec,
982 	},
983 	{
984 		.procname	= "panic_on_oom",
985 		.data		= &sysctl_panic_on_oom,
986 		.maxlen		= sizeof(sysctl_panic_on_oom),
987 		.mode		= 0644,
988 		.proc_handler	= proc_dointvec,
989 	},
990 	{
991 		.procname	= "oom_kill_allocating_task",
992 		.data		= &sysctl_oom_kill_allocating_task,
993 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
994 		.mode		= 0644,
995 		.proc_handler	= proc_dointvec,
996 	},
997 	{
998 		.procname	= "oom_dump_tasks",
999 		.data		= &sysctl_oom_dump_tasks,
1000 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1001 		.mode		= 0644,
1002 		.proc_handler	= proc_dointvec,
1003 	},
1004 	{
1005 		.procname	= "overcommit_ratio",
1006 		.data		= &sysctl_overcommit_ratio,
1007 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1008 		.mode		= 0644,
1009 		.proc_handler	= proc_dointvec,
1010 	},
1011 	{
1012 		.procname	= "page-cluster",
1013 		.data		= &page_cluster,
1014 		.maxlen		= sizeof(int),
1015 		.mode		= 0644,
1016 		.proc_handler	= proc_dointvec,
1017 	},
1018 	{
1019 		.procname	= "dirty_background_ratio",
1020 		.data		= &dirty_background_ratio,
1021 		.maxlen		= sizeof(dirty_background_ratio),
1022 		.mode		= 0644,
1023 		.proc_handler	= dirty_background_ratio_handler,
1024 		.extra1		= &zero,
1025 		.extra2		= &one_hundred,
1026 	},
1027 	{
1028 		.procname	= "dirty_background_bytes",
1029 		.data		= &dirty_background_bytes,
1030 		.maxlen		= sizeof(dirty_background_bytes),
1031 		.mode		= 0644,
1032 		.proc_handler	= dirty_background_bytes_handler,
1033 		.extra1		= &one_ul,
1034 	},
1035 	{
1036 		.procname	= "dirty_ratio",
1037 		.data		= &vm_dirty_ratio,
1038 		.maxlen		= sizeof(vm_dirty_ratio),
1039 		.mode		= 0644,
1040 		.proc_handler	= dirty_ratio_handler,
1041 		.extra1		= &zero,
1042 		.extra2		= &one_hundred,
1043 	},
1044 	{
1045 		.procname	= "dirty_bytes",
1046 		.data		= &vm_dirty_bytes,
1047 		.maxlen		= sizeof(vm_dirty_bytes),
1048 		.mode		= 0644,
1049 		.proc_handler	= dirty_bytes_handler,
1050 		.extra1		= &dirty_bytes_min,
1051 	},
1052 	{
1053 		.procname	= "dirty_writeback_centisecs",
1054 		.data		= &dirty_writeback_interval,
1055 		.maxlen		= sizeof(dirty_writeback_interval),
1056 		.mode		= 0644,
1057 		.proc_handler	= dirty_writeback_centisecs_handler,
1058 	},
1059 	{
1060 		.procname	= "dirty_expire_centisecs",
1061 		.data		= &dirty_expire_interval,
1062 		.maxlen		= sizeof(dirty_expire_interval),
1063 		.mode		= 0644,
1064 		.proc_handler	= proc_dointvec,
1065 	},
1066 	{
1067 		.procname	= "nr_pdflush_threads",
1068 		.data		= &nr_pdflush_threads,
1069 		.maxlen		= sizeof nr_pdflush_threads,
1070 		.mode		= 0444 /* read-only*/,
1071 		.proc_handler	= proc_dointvec,
1072 	},
1073 	{
1074 		.procname	= "swappiness",
1075 		.data		= &vm_swappiness,
1076 		.maxlen		= sizeof(vm_swappiness),
1077 		.mode		= 0644,
1078 		.proc_handler	= proc_dointvec_minmax,
1079 		.extra1		= &zero,
1080 		.extra2		= &one_hundred,
1081 	},
1082 #ifdef CONFIG_HUGETLB_PAGE
1083 	{
1084 		.procname	= "nr_hugepages",
1085 		.data		= NULL,
1086 		.maxlen		= sizeof(unsigned long),
1087 		.mode		= 0644,
1088 		.proc_handler	= hugetlb_sysctl_handler,
1089 		.extra1		= (void *)&hugetlb_zero,
1090 		.extra2		= (void *)&hugetlb_infinity,
1091 	},
1092 #ifdef CONFIG_NUMA
1093 	{
1094 		.procname       = "nr_hugepages_mempolicy",
1095 		.data           = NULL,
1096 		.maxlen         = sizeof(unsigned long),
1097 		.mode           = 0644,
1098 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1099 		.extra1		= (void *)&hugetlb_zero,
1100 		.extra2		= (void *)&hugetlb_infinity,
1101 	},
1102 #endif
1103 	 {
1104 		.procname	= "hugetlb_shm_group",
1105 		.data		= &sysctl_hugetlb_shm_group,
1106 		.maxlen		= sizeof(gid_t),
1107 		.mode		= 0644,
1108 		.proc_handler	= proc_dointvec,
1109 	 },
1110 	 {
1111 		.procname	= "hugepages_treat_as_movable",
1112 		.data		= &hugepages_treat_as_movable,
1113 		.maxlen		= sizeof(int),
1114 		.mode		= 0644,
1115 		.proc_handler	= hugetlb_treat_movable_handler,
1116 	},
1117 	{
1118 		.procname	= "nr_overcommit_hugepages",
1119 		.data		= NULL,
1120 		.maxlen		= sizeof(unsigned long),
1121 		.mode		= 0644,
1122 		.proc_handler	= hugetlb_overcommit_handler,
1123 		.extra1		= (void *)&hugetlb_zero,
1124 		.extra2		= (void *)&hugetlb_infinity,
1125 	},
1126 #endif
1127 	{
1128 		.procname	= "lowmem_reserve_ratio",
1129 		.data		= &sysctl_lowmem_reserve_ratio,
1130 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1131 		.mode		= 0644,
1132 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1133 	},
1134 	{
1135 		.procname	= "drop_caches",
1136 		.data		= &sysctl_drop_caches,
1137 		.maxlen		= sizeof(int),
1138 		.mode		= 0644,
1139 		.proc_handler	= drop_caches_sysctl_handler,
1140 	},
1141 #ifdef CONFIG_COMPACTION
1142 	{
1143 		.procname	= "compact_memory",
1144 		.data		= &sysctl_compact_memory,
1145 		.maxlen		= sizeof(int),
1146 		.mode		= 0200,
1147 		.proc_handler	= sysctl_compaction_handler,
1148 	},
1149 	{
1150 		.procname	= "extfrag_threshold",
1151 		.data		= &sysctl_extfrag_threshold,
1152 		.maxlen		= sizeof(int),
1153 		.mode		= 0644,
1154 		.proc_handler	= sysctl_extfrag_handler,
1155 		.extra1		= &min_extfrag_threshold,
1156 		.extra2		= &max_extfrag_threshold,
1157 	},
1158 
1159 #endif /* CONFIG_COMPACTION */
1160 	{
1161 		.procname	= "min_free_kbytes",
1162 		.data		= &min_free_kbytes,
1163 		.maxlen		= sizeof(min_free_kbytes),
1164 		.mode		= 0644,
1165 		.proc_handler	= min_free_kbytes_sysctl_handler,
1166 		.extra1		= &zero,
1167 	},
1168 	{
1169 		.procname	= "percpu_pagelist_fraction",
1170 		.data		= &percpu_pagelist_fraction,
1171 		.maxlen		= sizeof(percpu_pagelist_fraction),
1172 		.mode		= 0644,
1173 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1174 		.extra1		= &min_percpu_pagelist_fract,
1175 	},
1176 #ifdef CONFIG_MMU
1177 	{
1178 		.procname	= "max_map_count",
1179 		.data		= &sysctl_max_map_count,
1180 		.maxlen		= sizeof(sysctl_max_map_count),
1181 		.mode		= 0644,
1182 		.proc_handler	= proc_dointvec_minmax,
1183 		.extra1		= &zero,
1184 	},
1185 #else
1186 	{
1187 		.procname	= "nr_trim_pages",
1188 		.data		= &sysctl_nr_trim_pages,
1189 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1190 		.mode		= 0644,
1191 		.proc_handler	= proc_dointvec_minmax,
1192 		.extra1		= &zero,
1193 	},
1194 #endif
1195 	{
1196 		.procname	= "laptop_mode",
1197 		.data		= &laptop_mode,
1198 		.maxlen		= sizeof(laptop_mode),
1199 		.mode		= 0644,
1200 		.proc_handler	= proc_dointvec_jiffies,
1201 	},
1202 	{
1203 		.procname	= "block_dump",
1204 		.data		= &block_dump,
1205 		.maxlen		= sizeof(block_dump),
1206 		.mode		= 0644,
1207 		.proc_handler	= proc_dointvec,
1208 		.extra1		= &zero,
1209 	},
1210 	{
1211 		.procname	= "vfs_cache_pressure",
1212 		.data		= &sysctl_vfs_cache_pressure,
1213 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1214 		.mode		= 0644,
1215 		.proc_handler	= proc_dointvec,
1216 		.extra1		= &zero,
1217 	},
1218 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1219 	{
1220 		.procname	= "legacy_va_layout",
1221 		.data		= &sysctl_legacy_va_layout,
1222 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1223 		.mode		= 0644,
1224 		.proc_handler	= proc_dointvec,
1225 		.extra1		= &zero,
1226 	},
1227 #endif
1228 #ifdef CONFIG_NUMA
1229 	{
1230 		.procname	= "zone_reclaim_mode",
1231 		.data		= &zone_reclaim_mode,
1232 		.maxlen		= sizeof(zone_reclaim_mode),
1233 		.mode		= 0644,
1234 		.proc_handler	= proc_dointvec,
1235 		.extra1		= &zero,
1236 	},
1237 	{
1238 		.procname	= "min_unmapped_ratio",
1239 		.data		= &sysctl_min_unmapped_ratio,
1240 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1241 		.mode		= 0644,
1242 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1243 		.extra1		= &zero,
1244 		.extra2		= &one_hundred,
1245 	},
1246 	{
1247 		.procname	= "min_slab_ratio",
1248 		.data		= &sysctl_min_slab_ratio,
1249 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1250 		.mode		= 0644,
1251 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1252 		.extra1		= &zero,
1253 		.extra2		= &one_hundred,
1254 	},
1255 #endif
1256 #ifdef CONFIG_SMP
1257 	{
1258 		.procname	= "stat_interval",
1259 		.data		= &sysctl_stat_interval,
1260 		.maxlen		= sizeof(sysctl_stat_interval),
1261 		.mode		= 0644,
1262 		.proc_handler	= proc_dointvec_jiffies,
1263 	},
1264 #endif
1265 #ifdef CONFIG_MMU
1266 	{
1267 		.procname	= "mmap_min_addr",
1268 		.data		= &dac_mmap_min_addr,
1269 		.maxlen		= sizeof(unsigned long),
1270 		.mode		= 0644,
1271 		.proc_handler	= mmap_min_addr_handler,
1272 	},
1273 #endif
1274 #ifdef CONFIG_NUMA
1275 	{
1276 		.procname	= "numa_zonelist_order",
1277 		.data		= &numa_zonelist_order,
1278 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1279 		.mode		= 0644,
1280 		.proc_handler	= numa_zonelist_order_handler,
1281 	},
1282 #endif
1283 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1284    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1285 	{
1286 		.procname	= "vdso_enabled",
1287 		.data		= &vdso_enabled,
1288 		.maxlen		= sizeof(vdso_enabled),
1289 		.mode		= 0644,
1290 		.proc_handler	= proc_dointvec,
1291 		.extra1		= &zero,
1292 	},
1293 #endif
1294 #ifdef CONFIG_HIGHMEM
1295 	{
1296 		.procname	= "highmem_is_dirtyable",
1297 		.data		= &vm_highmem_is_dirtyable,
1298 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1299 		.mode		= 0644,
1300 		.proc_handler	= proc_dointvec_minmax,
1301 		.extra1		= &zero,
1302 		.extra2		= &one,
1303 	},
1304 #endif
1305 	{
1306 		.procname	= "scan_unevictable_pages",
1307 		.data		= &scan_unevictable_pages,
1308 		.maxlen		= sizeof(scan_unevictable_pages),
1309 		.mode		= 0644,
1310 		.proc_handler	= scan_unevictable_handler,
1311 	},
1312 #ifdef CONFIG_MEMORY_FAILURE
1313 	{
1314 		.procname	= "memory_failure_early_kill",
1315 		.data		= &sysctl_memory_failure_early_kill,
1316 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1317 		.mode		= 0644,
1318 		.proc_handler	= proc_dointvec_minmax,
1319 		.extra1		= &zero,
1320 		.extra2		= &one,
1321 	},
1322 	{
1323 		.procname	= "memory_failure_recovery",
1324 		.data		= &sysctl_memory_failure_recovery,
1325 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1326 		.mode		= 0644,
1327 		.proc_handler	= proc_dointvec_minmax,
1328 		.extra1		= &zero,
1329 		.extra2		= &one,
1330 	},
1331 #endif
1332 	{ }
1333 };
1334 
1335 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1336 static struct ctl_table binfmt_misc_table[] = {
1337 	{ }
1338 };
1339 #endif
1340 
1341 static struct ctl_table fs_table[] = {
1342 	{
1343 		.procname	= "inode-nr",
1344 		.data		= &inodes_stat,
1345 		.maxlen		= 2*sizeof(int),
1346 		.mode		= 0444,
1347 		.proc_handler	= proc_nr_inodes,
1348 	},
1349 	{
1350 		.procname	= "inode-state",
1351 		.data		= &inodes_stat,
1352 		.maxlen		= 7*sizeof(int),
1353 		.mode		= 0444,
1354 		.proc_handler	= proc_nr_inodes,
1355 	},
1356 	{
1357 		.procname	= "file-nr",
1358 		.data		= &files_stat,
1359 		.maxlen		= sizeof(files_stat),
1360 		.mode		= 0444,
1361 		.proc_handler	= proc_nr_files,
1362 	},
1363 	{
1364 		.procname	= "file-max",
1365 		.data		= &files_stat.max_files,
1366 		.maxlen		= sizeof(files_stat.max_files),
1367 		.mode		= 0644,
1368 		.proc_handler	= proc_doulongvec_minmax,
1369 	},
1370 	{
1371 		.procname	= "nr_open",
1372 		.data		= &sysctl_nr_open,
1373 		.maxlen		= sizeof(int),
1374 		.mode		= 0644,
1375 		.proc_handler	= proc_dointvec_minmax,
1376 		.extra1		= &sysctl_nr_open_min,
1377 		.extra2		= &sysctl_nr_open_max,
1378 	},
1379 	{
1380 		.procname	= "dentry-state",
1381 		.data		= &dentry_stat,
1382 		.maxlen		= 6*sizeof(int),
1383 		.mode		= 0444,
1384 		.proc_handler	= proc_nr_dentry,
1385 	},
1386 	{
1387 		.procname	= "overflowuid",
1388 		.data		= &fs_overflowuid,
1389 		.maxlen		= sizeof(int),
1390 		.mode		= 0644,
1391 		.proc_handler	= proc_dointvec_minmax,
1392 		.extra1		= &minolduid,
1393 		.extra2		= &maxolduid,
1394 	},
1395 	{
1396 		.procname	= "overflowgid",
1397 		.data		= &fs_overflowgid,
1398 		.maxlen		= sizeof(int),
1399 		.mode		= 0644,
1400 		.proc_handler	= proc_dointvec_minmax,
1401 		.extra1		= &minolduid,
1402 		.extra2		= &maxolduid,
1403 	},
1404 #ifdef CONFIG_FILE_LOCKING
1405 	{
1406 		.procname	= "leases-enable",
1407 		.data		= &leases_enable,
1408 		.maxlen		= sizeof(int),
1409 		.mode		= 0644,
1410 		.proc_handler	= proc_dointvec,
1411 	},
1412 #endif
1413 #ifdef CONFIG_DNOTIFY
1414 	{
1415 		.procname	= "dir-notify-enable",
1416 		.data		= &dir_notify_enable,
1417 		.maxlen		= sizeof(int),
1418 		.mode		= 0644,
1419 		.proc_handler	= proc_dointvec,
1420 	},
1421 #endif
1422 #ifdef CONFIG_MMU
1423 #ifdef CONFIG_FILE_LOCKING
1424 	{
1425 		.procname	= "lease-break-time",
1426 		.data		= &lease_break_time,
1427 		.maxlen		= sizeof(int),
1428 		.mode		= 0644,
1429 		.proc_handler	= proc_dointvec,
1430 	},
1431 #endif
1432 #ifdef CONFIG_AIO
1433 	{
1434 		.procname	= "aio-nr",
1435 		.data		= &aio_nr,
1436 		.maxlen		= sizeof(aio_nr),
1437 		.mode		= 0444,
1438 		.proc_handler	= proc_doulongvec_minmax,
1439 	},
1440 	{
1441 		.procname	= "aio-max-nr",
1442 		.data		= &aio_max_nr,
1443 		.maxlen		= sizeof(aio_max_nr),
1444 		.mode		= 0644,
1445 		.proc_handler	= proc_doulongvec_minmax,
1446 	},
1447 #endif /* CONFIG_AIO */
1448 #ifdef CONFIG_INOTIFY_USER
1449 	{
1450 		.procname	= "inotify",
1451 		.mode		= 0555,
1452 		.child		= inotify_table,
1453 	},
1454 #endif
1455 #ifdef CONFIG_EPOLL
1456 	{
1457 		.procname	= "epoll",
1458 		.mode		= 0555,
1459 		.child		= epoll_table,
1460 	},
1461 #endif
1462 #endif
1463 	{
1464 		.procname	= "suid_dumpable",
1465 		.data		= &suid_dumpable,
1466 		.maxlen		= sizeof(int),
1467 		.mode		= 0644,
1468 		.proc_handler	= proc_dointvec_minmax,
1469 		.extra1		= &zero,
1470 		.extra2		= &two,
1471 	},
1472 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1473 	{
1474 		.procname	= "binfmt_misc",
1475 		.mode		= 0555,
1476 		.child		= binfmt_misc_table,
1477 	},
1478 #endif
1479 	{
1480 		.procname	= "pipe-max-size",
1481 		.data		= &pipe_max_size,
1482 		.maxlen		= sizeof(int),
1483 		.mode		= 0644,
1484 		.proc_handler	= &pipe_proc_fn,
1485 		.extra1		= &pipe_min_size,
1486 	},
1487 	{ }
1488 };
1489 
1490 static struct ctl_table debug_table[] = {
1491 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1492     defined(CONFIG_S390)
1493 	{
1494 		.procname	= "exception-trace",
1495 		.data		= &show_unhandled_signals,
1496 		.maxlen		= sizeof(int),
1497 		.mode		= 0644,
1498 		.proc_handler	= proc_dointvec
1499 	},
1500 #endif
1501 #if defined(CONFIG_OPTPROBES)
1502 	{
1503 		.procname	= "kprobes-optimization",
1504 		.data		= &sysctl_kprobes_optimization,
1505 		.maxlen		= sizeof(int),
1506 		.mode		= 0644,
1507 		.proc_handler	= proc_kprobes_optimization_handler,
1508 		.extra1		= &zero,
1509 		.extra2		= &one,
1510 	},
1511 #endif
1512 	{ }
1513 };
1514 
1515 static struct ctl_table dev_table[] = {
1516 	{ }
1517 };
1518 
1519 static DEFINE_SPINLOCK(sysctl_lock);
1520 
1521 /* called under sysctl_lock */
1522 static int use_table(struct ctl_table_header *p)
1523 {
1524 	if (unlikely(p->unregistering))
1525 		return 0;
1526 	p->used++;
1527 	return 1;
1528 }
1529 
1530 /* called under sysctl_lock */
1531 static void unuse_table(struct ctl_table_header *p)
1532 {
1533 	if (!--p->used)
1534 		if (unlikely(p->unregistering))
1535 			complete(p->unregistering);
1536 }
1537 
1538 /* called under sysctl_lock, will reacquire if has to wait */
1539 static void start_unregistering(struct ctl_table_header *p)
1540 {
1541 	/*
1542 	 * if p->used is 0, nobody will ever touch that entry again;
1543 	 * we'll eliminate all paths to it before dropping sysctl_lock
1544 	 */
1545 	if (unlikely(p->used)) {
1546 		struct completion wait;
1547 		init_completion(&wait);
1548 		p->unregistering = &wait;
1549 		spin_unlock(&sysctl_lock);
1550 		wait_for_completion(&wait);
1551 		spin_lock(&sysctl_lock);
1552 	} else {
1553 		/* anything non-NULL; we'll never dereference it */
1554 		p->unregistering = ERR_PTR(-EINVAL);
1555 	}
1556 	/*
1557 	 * do not remove from the list until nobody holds it; walking the
1558 	 * list in do_sysctl() relies on that.
1559 	 */
1560 	list_del_init(&p->ctl_entry);
1561 }
1562 
1563 void sysctl_head_get(struct ctl_table_header *head)
1564 {
1565 	spin_lock(&sysctl_lock);
1566 	head->count++;
1567 	spin_unlock(&sysctl_lock);
1568 }
1569 
1570 static void free_head(struct rcu_head *rcu)
1571 {
1572 	kfree(container_of(rcu, struct ctl_table_header, rcu));
1573 }
1574 
1575 void sysctl_head_put(struct ctl_table_header *head)
1576 {
1577 	spin_lock(&sysctl_lock);
1578 	if (!--head->count)
1579 		call_rcu(&head->rcu, free_head);
1580 	spin_unlock(&sysctl_lock);
1581 }
1582 
1583 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1584 {
1585 	if (!head)
1586 		BUG();
1587 	spin_lock(&sysctl_lock);
1588 	if (!use_table(head))
1589 		head = ERR_PTR(-ENOENT);
1590 	spin_unlock(&sysctl_lock);
1591 	return head;
1592 }
1593 
1594 void sysctl_head_finish(struct ctl_table_header *head)
1595 {
1596 	if (!head)
1597 		return;
1598 	spin_lock(&sysctl_lock);
1599 	unuse_table(head);
1600 	spin_unlock(&sysctl_lock);
1601 }
1602 
1603 static struct ctl_table_set *
1604 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1605 {
1606 	struct ctl_table_set *set = &root->default_set;
1607 	if (root->lookup)
1608 		set = root->lookup(root, namespaces);
1609 	return set;
1610 }
1611 
1612 static struct list_head *
1613 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1614 {
1615 	struct ctl_table_set *set = lookup_header_set(root, namespaces);
1616 	return &set->list;
1617 }
1618 
1619 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1620 					    struct ctl_table_header *prev)
1621 {
1622 	struct ctl_table_root *root;
1623 	struct list_head *header_list;
1624 	struct ctl_table_header *head;
1625 	struct list_head *tmp;
1626 
1627 	spin_lock(&sysctl_lock);
1628 	if (prev) {
1629 		head = prev;
1630 		tmp = &prev->ctl_entry;
1631 		unuse_table(prev);
1632 		goto next;
1633 	}
1634 	tmp = &root_table_header.ctl_entry;
1635 	for (;;) {
1636 		head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1637 
1638 		if (!use_table(head))
1639 			goto next;
1640 		spin_unlock(&sysctl_lock);
1641 		return head;
1642 	next:
1643 		root = head->root;
1644 		tmp = tmp->next;
1645 		header_list = lookup_header_list(root, namespaces);
1646 		if (tmp != header_list)
1647 			continue;
1648 
1649 		do {
1650 			root = list_entry(root->root_list.next,
1651 					struct ctl_table_root, root_list);
1652 			if (root == &sysctl_table_root)
1653 				goto out;
1654 			header_list = lookup_header_list(root, namespaces);
1655 		} while (list_empty(header_list));
1656 		tmp = header_list->next;
1657 	}
1658 out:
1659 	spin_unlock(&sysctl_lock);
1660 	return NULL;
1661 }
1662 
1663 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1664 {
1665 	return __sysctl_head_next(current->nsproxy, prev);
1666 }
1667 
1668 void register_sysctl_root(struct ctl_table_root *root)
1669 {
1670 	spin_lock(&sysctl_lock);
1671 	list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1672 	spin_unlock(&sysctl_lock);
1673 }
1674 
1675 /*
1676  * sysctl_perm does NOT grant the superuser all rights automatically, because
1677  * some sysctl variables are readonly even to root.
1678  */
1679 
1680 static int test_perm(int mode, int op)
1681 {
1682 	if (!current_euid())
1683 		mode >>= 6;
1684 	else if (in_egroup_p(0))
1685 		mode >>= 3;
1686 	if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1687 		return 0;
1688 	return -EACCES;
1689 }
1690 
1691 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1692 {
1693 	int error;
1694 	int mode;
1695 
1696 	error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1697 	if (error)
1698 		return error;
1699 
1700 	if (root->permissions)
1701 		mode = root->permissions(root, current->nsproxy, table);
1702 	else
1703 		mode = table->mode;
1704 
1705 	return test_perm(mode, op);
1706 }
1707 
1708 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1709 {
1710 	for (; table->procname; table++) {
1711 		table->parent = parent;
1712 		if (table->child)
1713 			sysctl_set_parent(table, table->child);
1714 	}
1715 }
1716 
1717 static __init int sysctl_init(void)
1718 {
1719 	sysctl_set_parent(NULL, root_table);
1720 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1721 	sysctl_check_table(current->nsproxy, root_table);
1722 #endif
1723 	return 0;
1724 }
1725 
1726 core_initcall(sysctl_init);
1727 
1728 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1729 				      struct ctl_table *table)
1730 {
1731 	struct ctl_table *p;
1732 	const char *s = branch->procname;
1733 
1734 	/* branch should have named subdirectory as its first element */
1735 	if (!s || !branch->child)
1736 		return NULL;
1737 
1738 	/* ... and nothing else */
1739 	if (branch[1].procname)
1740 		return NULL;
1741 
1742 	/* table should contain subdirectory with the same name */
1743 	for (p = table; p->procname; p++) {
1744 		if (!p->child)
1745 			continue;
1746 		if (p->procname && strcmp(p->procname, s) == 0)
1747 			return p;
1748 	}
1749 	return NULL;
1750 }
1751 
1752 /* see if attaching q to p would be an improvement */
1753 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1754 {
1755 	struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1756 	struct ctl_table *next;
1757 	int is_better = 0;
1758 	int not_in_parent = !p->attached_by;
1759 
1760 	while ((next = is_branch_in(by, to)) != NULL) {
1761 		if (by == q->attached_by)
1762 			is_better = 1;
1763 		if (to == p->attached_by)
1764 			not_in_parent = 1;
1765 		by = by->child;
1766 		to = next->child;
1767 	}
1768 
1769 	if (is_better && not_in_parent) {
1770 		q->attached_by = by;
1771 		q->attached_to = to;
1772 		q->parent = p;
1773 	}
1774 }
1775 
1776 /**
1777  * __register_sysctl_paths - register a sysctl hierarchy
1778  * @root: List of sysctl headers to register on
1779  * @namespaces: Data to compute which lists of sysctl entries are visible
1780  * @path: The path to the directory the sysctl table is in.
1781  * @table: the top-level table structure
1782  *
1783  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1784  * array. A completely 0 filled entry terminates the table.
1785  *
1786  * The members of the &struct ctl_table structure are used as follows:
1787  *
1788  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1789  *            enter a sysctl file
1790  *
1791  * data - a pointer to data for use by proc_handler
1792  *
1793  * maxlen - the maximum size in bytes of the data
1794  *
1795  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1796  *
1797  * child - a pointer to the child sysctl table if this entry is a directory, or
1798  *         %NULL.
1799  *
1800  * proc_handler - the text handler routine (described below)
1801  *
1802  * de - for internal use by the sysctl routines
1803  *
1804  * extra1, extra2 - extra pointers usable by the proc handler routines
1805  *
1806  * Leaf nodes in the sysctl tree will be represented by a single file
1807  * under /proc; non-leaf nodes will be represented by directories.
1808  *
1809  * sysctl(2) can automatically manage read and write requests through
1810  * the sysctl table.  The data and maxlen fields of the ctl_table
1811  * struct enable minimal validation of the values being written to be
1812  * performed, and the mode field allows minimal authentication.
1813  *
1814  * There must be a proc_handler routine for any terminal nodes
1815  * mirrored under /proc/sys (non-terminals are handled by a built-in
1816  * directory handler).  Several default handlers are available to
1817  * cover common cases -
1818  *
1819  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1820  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1821  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1822  *
1823  * It is the handler's job to read the input buffer from user memory
1824  * and process it. The handler should return 0 on success.
1825  *
1826  * This routine returns %NULL on a failure to register, and a pointer
1827  * to the table header on success.
1828  */
1829 struct ctl_table_header *__register_sysctl_paths(
1830 	struct ctl_table_root *root,
1831 	struct nsproxy *namespaces,
1832 	const struct ctl_path *path, struct ctl_table *table)
1833 {
1834 	struct ctl_table_header *header;
1835 	struct ctl_table *new, **prevp;
1836 	unsigned int n, npath;
1837 	struct ctl_table_set *set;
1838 
1839 	/* Count the path components */
1840 	for (npath = 0; path[npath].procname; ++npath)
1841 		;
1842 
1843 	/*
1844 	 * For each path component, allocate a 2-element ctl_table array.
1845 	 * The first array element will be filled with the sysctl entry
1846 	 * for this, the second will be the sentinel (procname == 0).
1847 	 *
1848 	 * We allocate everything in one go so that we don't have to
1849 	 * worry about freeing additional memory in unregister_sysctl_table.
1850 	 */
1851 	header = kzalloc(sizeof(struct ctl_table_header) +
1852 			 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1853 	if (!header)
1854 		return NULL;
1855 
1856 	new = (struct ctl_table *) (header + 1);
1857 
1858 	/* Now connect the dots */
1859 	prevp = &header->ctl_table;
1860 	for (n = 0; n < npath; ++n, ++path) {
1861 		/* Copy the procname */
1862 		new->procname = path->procname;
1863 		new->mode     = 0555;
1864 
1865 		*prevp = new;
1866 		prevp = &new->child;
1867 
1868 		new += 2;
1869 	}
1870 	*prevp = table;
1871 	header->ctl_table_arg = table;
1872 
1873 	INIT_LIST_HEAD(&header->ctl_entry);
1874 	header->used = 0;
1875 	header->unregistering = NULL;
1876 	header->root = root;
1877 	sysctl_set_parent(NULL, header->ctl_table);
1878 	header->count = 1;
1879 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1880 	if (sysctl_check_table(namespaces, header->ctl_table)) {
1881 		kfree(header);
1882 		return NULL;
1883 	}
1884 #endif
1885 	spin_lock(&sysctl_lock);
1886 	header->set = lookup_header_set(root, namespaces);
1887 	header->attached_by = header->ctl_table;
1888 	header->attached_to = root_table;
1889 	header->parent = &root_table_header;
1890 	for (set = header->set; set; set = set->parent) {
1891 		struct ctl_table_header *p;
1892 		list_for_each_entry(p, &set->list, ctl_entry) {
1893 			if (p->unregistering)
1894 				continue;
1895 			try_attach(p, header);
1896 		}
1897 	}
1898 	header->parent->count++;
1899 	list_add_tail(&header->ctl_entry, &header->set->list);
1900 	spin_unlock(&sysctl_lock);
1901 
1902 	return header;
1903 }
1904 
1905 /**
1906  * register_sysctl_table_path - register a sysctl table hierarchy
1907  * @path: The path to the directory the sysctl table is in.
1908  * @table: the top-level table structure
1909  *
1910  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1911  * array. A completely 0 filled entry terminates the table.
1912  *
1913  * See __register_sysctl_paths for more details.
1914  */
1915 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1916 						struct ctl_table *table)
1917 {
1918 	return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1919 					path, table);
1920 }
1921 
1922 /**
1923  * register_sysctl_table - register a sysctl table hierarchy
1924  * @table: the top-level table structure
1925  *
1926  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1927  * array. A completely 0 filled entry terminates the table.
1928  *
1929  * See register_sysctl_paths for more details.
1930  */
1931 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1932 {
1933 	static const struct ctl_path null_path[] = { {} };
1934 
1935 	return register_sysctl_paths(null_path, table);
1936 }
1937 
1938 /**
1939  * unregister_sysctl_table - unregister a sysctl table hierarchy
1940  * @header: the header returned from register_sysctl_table
1941  *
1942  * Unregisters the sysctl table and all children. proc entries may not
1943  * actually be removed until they are no longer used by anyone.
1944  */
1945 void unregister_sysctl_table(struct ctl_table_header * header)
1946 {
1947 	might_sleep();
1948 
1949 	if (header == NULL)
1950 		return;
1951 
1952 	spin_lock(&sysctl_lock);
1953 	start_unregistering(header);
1954 	if (!--header->parent->count) {
1955 		WARN_ON(1);
1956 		call_rcu(&header->parent->rcu, free_head);
1957 	}
1958 	if (!--header->count)
1959 		call_rcu(&header->rcu, free_head);
1960 	spin_unlock(&sysctl_lock);
1961 }
1962 
1963 int sysctl_is_seen(struct ctl_table_header *p)
1964 {
1965 	struct ctl_table_set *set = p->set;
1966 	int res;
1967 	spin_lock(&sysctl_lock);
1968 	if (p->unregistering)
1969 		res = 0;
1970 	else if (!set->is_seen)
1971 		res = 1;
1972 	else
1973 		res = set->is_seen(set);
1974 	spin_unlock(&sysctl_lock);
1975 	return res;
1976 }
1977 
1978 void setup_sysctl_set(struct ctl_table_set *p,
1979 	struct ctl_table_set *parent,
1980 	int (*is_seen)(struct ctl_table_set *))
1981 {
1982 	INIT_LIST_HEAD(&p->list);
1983 	p->parent = parent ? parent : &sysctl_table_root.default_set;
1984 	p->is_seen = is_seen;
1985 }
1986 
1987 #else /* !CONFIG_SYSCTL */
1988 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1989 {
1990 	return NULL;
1991 }
1992 
1993 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1994 						    struct ctl_table *table)
1995 {
1996 	return NULL;
1997 }
1998 
1999 void unregister_sysctl_table(struct ctl_table_header * table)
2000 {
2001 }
2002 
2003 void setup_sysctl_set(struct ctl_table_set *p,
2004 	struct ctl_table_set *parent,
2005 	int (*is_seen)(struct ctl_table_set *))
2006 {
2007 }
2008 
2009 void sysctl_head_put(struct ctl_table_header *head)
2010 {
2011 }
2012 
2013 #endif /* CONFIG_SYSCTL */
2014 
2015 /*
2016  * /proc/sys support
2017  */
2018 
2019 #ifdef CONFIG_PROC_SYSCTL
2020 
2021 static int _proc_do_string(void* data, int maxlen, int write,
2022 			   void __user *buffer,
2023 			   size_t *lenp, loff_t *ppos)
2024 {
2025 	size_t len;
2026 	char __user *p;
2027 	char c;
2028 
2029 	if (!data || !maxlen || !*lenp) {
2030 		*lenp = 0;
2031 		return 0;
2032 	}
2033 
2034 	if (write) {
2035 		len = 0;
2036 		p = buffer;
2037 		while (len < *lenp) {
2038 			if (get_user(c, p++))
2039 				return -EFAULT;
2040 			if (c == 0 || c == '\n')
2041 				break;
2042 			len++;
2043 		}
2044 		if (len >= maxlen)
2045 			len = maxlen-1;
2046 		if(copy_from_user(data, buffer, len))
2047 			return -EFAULT;
2048 		((char *) data)[len] = 0;
2049 		*ppos += *lenp;
2050 	} else {
2051 		len = strlen(data);
2052 		if (len > maxlen)
2053 			len = maxlen;
2054 
2055 		if (*ppos > len) {
2056 			*lenp = 0;
2057 			return 0;
2058 		}
2059 
2060 		data += *ppos;
2061 		len  -= *ppos;
2062 
2063 		if (len > *lenp)
2064 			len = *lenp;
2065 		if (len)
2066 			if(copy_to_user(buffer, data, len))
2067 				return -EFAULT;
2068 		if (len < *lenp) {
2069 			if(put_user('\n', ((char __user *) buffer) + len))
2070 				return -EFAULT;
2071 			len++;
2072 		}
2073 		*lenp = len;
2074 		*ppos += len;
2075 	}
2076 	return 0;
2077 }
2078 
2079 /**
2080  * proc_dostring - read a string sysctl
2081  * @table: the sysctl table
2082  * @write: %TRUE if this is a write to the sysctl file
2083  * @buffer: the user buffer
2084  * @lenp: the size of the user buffer
2085  * @ppos: file position
2086  *
2087  * Reads/writes a string from/to the user buffer. If the kernel
2088  * buffer provided is not large enough to hold the string, the
2089  * string is truncated. The copied string is %NULL-terminated.
2090  * If the string is being read by the user process, it is copied
2091  * and a newline '\n' is added. It is truncated if the buffer is
2092  * not large enough.
2093  *
2094  * Returns 0 on success.
2095  */
2096 int proc_dostring(struct ctl_table *table, int write,
2097 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2098 {
2099 	return _proc_do_string(table->data, table->maxlen, write,
2100 			       buffer, lenp, ppos);
2101 }
2102 
2103 static size_t proc_skip_spaces(char **buf)
2104 {
2105 	size_t ret;
2106 	char *tmp = skip_spaces(*buf);
2107 	ret = tmp - *buf;
2108 	*buf = tmp;
2109 	return ret;
2110 }
2111 
2112 static void proc_skip_char(char **buf, size_t *size, const char v)
2113 {
2114 	while (*size) {
2115 		if (**buf != v)
2116 			break;
2117 		(*size)--;
2118 		(*buf)++;
2119 	}
2120 }
2121 
2122 #define TMPBUFLEN 22
2123 /**
2124  * proc_get_long - reads an ASCII formatted integer from a user buffer
2125  *
2126  * @buf: a kernel buffer
2127  * @size: size of the kernel buffer
2128  * @val: this is where the number will be stored
2129  * @neg: set to %TRUE if number is negative
2130  * @perm_tr: a vector which contains the allowed trailers
2131  * @perm_tr_len: size of the perm_tr vector
2132  * @tr: pointer to store the trailer character
2133  *
2134  * In case of success %0 is returned and @buf and @size are updated with
2135  * the amount of bytes read. If @tr is non-NULL and a trailing
2136  * character exists (size is non-zero after returning from this
2137  * function), @tr is updated with the trailing character.
2138  */
2139 static int proc_get_long(char **buf, size_t *size,
2140 			  unsigned long *val, bool *neg,
2141 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2142 {
2143 	int len;
2144 	char *p, tmp[TMPBUFLEN];
2145 
2146 	if (!*size)
2147 		return -EINVAL;
2148 
2149 	len = *size;
2150 	if (len > TMPBUFLEN - 1)
2151 		len = TMPBUFLEN - 1;
2152 
2153 	memcpy(tmp, *buf, len);
2154 
2155 	tmp[len] = 0;
2156 	p = tmp;
2157 	if (*p == '-' && *size > 1) {
2158 		*neg = true;
2159 		p++;
2160 	} else
2161 		*neg = false;
2162 	if (!isdigit(*p))
2163 		return -EINVAL;
2164 
2165 	*val = simple_strtoul(p, &p, 0);
2166 
2167 	len = p - tmp;
2168 
2169 	/* We don't know if the next char is whitespace thus we may accept
2170 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2171 	 * (e.g. 123...1). So lets not allow such large numbers. */
2172 	if (len == TMPBUFLEN - 1)
2173 		return -EINVAL;
2174 
2175 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2176 		return -EINVAL;
2177 
2178 	if (tr && (len < *size))
2179 		*tr = *p;
2180 
2181 	*buf += len;
2182 	*size -= len;
2183 
2184 	return 0;
2185 }
2186 
2187 /**
2188  * proc_put_long - converts an integer to a decimal ASCII formatted string
2189  *
2190  * @buf: the user buffer
2191  * @size: the size of the user buffer
2192  * @val: the integer to be converted
2193  * @neg: sign of the number, %TRUE for negative
2194  *
2195  * In case of success %0 is returned and @buf and @size are updated with
2196  * the amount of bytes written.
2197  */
2198 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2199 			  bool neg)
2200 {
2201 	int len;
2202 	char tmp[TMPBUFLEN], *p = tmp;
2203 
2204 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2205 	len = strlen(tmp);
2206 	if (len > *size)
2207 		len = *size;
2208 	if (copy_to_user(*buf, tmp, len))
2209 		return -EFAULT;
2210 	*size -= len;
2211 	*buf += len;
2212 	return 0;
2213 }
2214 #undef TMPBUFLEN
2215 
2216 static int proc_put_char(void __user **buf, size_t *size, char c)
2217 {
2218 	if (*size) {
2219 		char __user **buffer = (char __user **)buf;
2220 		if (put_user(c, *buffer))
2221 			return -EFAULT;
2222 		(*size)--, (*buffer)++;
2223 		*buf = *buffer;
2224 	}
2225 	return 0;
2226 }
2227 
2228 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2229 				 int *valp,
2230 				 int write, void *data)
2231 {
2232 	if (write) {
2233 		*valp = *negp ? -*lvalp : *lvalp;
2234 	} else {
2235 		int val = *valp;
2236 		if (val < 0) {
2237 			*negp = true;
2238 			*lvalp = (unsigned long)-val;
2239 		} else {
2240 			*negp = false;
2241 			*lvalp = (unsigned long)val;
2242 		}
2243 	}
2244 	return 0;
2245 }
2246 
2247 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2248 
2249 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2250 		  int write, void __user *buffer,
2251 		  size_t *lenp, loff_t *ppos,
2252 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2253 			      int write, void *data),
2254 		  void *data)
2255 {
2256 	int *i, vleft, first = 1, err = 0;
2257 	unsigned long page = 0;
2258 	size_t left;
2259 	char *kbuf;
2260 
2261 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2262 		*lenp = 0;
2263 		return 0;
2264 	}
2265 
2266 	i = (int *) tbl_data;
2267 	vleft = table->maxlen / sizeof(*i);
2268 	left = *lenp;
2269 
2270 	if (!conv)
2271 		conv = do_proc_dointvec_conv;
2272 
2273 	if (write) {
2274 		if (left > PAGE_SIZE - 1)
2275 			left = PAGE_SIZE - 1;
2276 		page = __get_free_page(GFP_TEMPORARY);
2277 		kbuf = (char *) page;
2278 		if (!kbuf)
2279 			return -ENOMEM;
2280 		if (copy_from_user(kbuf, buffer, left)) {
2281 			err = -EFAULT;
2282 			goto free;
2283 		}
2284 		kbuf[left] = 0;
2285 	}
2286 
2287 	for (; left && vleft--; i++, first=0) {
2288 		unsigned long lval;
2289 		bool neg;
2290 
2291 		if (write) {
2292 			left -= proc_skip_spaces(&kbuf);
2293 
2294 			if (!left)
2295 				break;
2296 			err = proc_get_long(&kbuf, &left, &lval, &neg,
2297 					     proc_wspace_sep,
2298 					     sizeof(proc_wspace_sep), NULL);
2299 			if (err)
2300 				break;
2301 			if (conv(&neg, &lval, i, 1, data)) {
2302 				err = -EINVAL;
2303 				break;
2304 			}
2305 		} else {
2306 			if (conv(&neg, &lval, i, 0, data)) {
2307 				err = -EINVAL;
2308 				break;
2309 			}
2310 			if (!first)
2311 				err = proc_put_char(&buffer, &left, '\t');
2312 			if (err)
2313 				break;
2314 			err = proc_put_long(&buffer, &left, lval, neg);
2315 			if (err)
2316 				break;
2317 		}
2318 	}
2319 
2320 	if (!write && !first && left && !err)
2321 		err = proc_put_char(&buffer, &left, '\n');
2322 	if (write && !err && left)
2323 		left -= proc_skip_spaces(&kbuf);
2324 free:
2325 	if (write) {
2326 		free_page(page);
2327 		if (first)
2328 			return err ? : -EINVAL;
2329 	}
2330 	*lenp -= left;
2331 	*ppos += *lenp;
2332 	return err;
2333 }
2334 
2335 static int do_proc_dointvec(struct ctl_table *table, int write,
2336 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2337 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2338 			      int write, void *data),
2339 		  void *data)
2340 {
2341 	return __do_proc_dointvec(table->data, table, write,
2342 			buffer, lenp, ppos, conv, data);
2343 }
2344 
2345 /**
2346  * proc_dointvec - read a vector of integers
2347  * @table: the sysctl table
2348  * @write: %TRUE if this is a write to the sysctl file
2349  * @buffer: the user buffer
2350  * @lenp: the size of the user buffer
2351  * @ppos: file position
2352  *
2353  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2354  * values from/to the user buffer, treated as an ASCII string.
2355  *
2356  * Returns 0 on success.
2357  */
2358 int proc_dointvec(struct ctl_table *table, int write,
2359 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2360 {
2361     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2362 		    	    NULL,NULL);
2363 }
2364 
2365 /*
2366  * Taint values can only be increased
2367  * This means we can safely use a temporary.
2368  */
2369 static int proc_taint(struct ctl_table *table, int write,
2370 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2371 {
2372 	struct ctl_table t;
2373 	unsigned long tmptaint = get_taint();
2374 	int err;
2375 
2376 	if (write && !capable(CAP_SYS_ADMIN))
2377 		return -EPERM;
2378 
2379 	t = *table;
2380 	t.data = &tmptaint;
2381 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2382 	if (err < 0)
2383 		return err;
2384 
2385 	if (write) {
2386 		/*
2387 		 * Poor man's atomic or. Not worth adding a primitive
2388 		 * to everyone's atomic.h for this
2389 		 */
2390 		int i;
2391 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2392 			if ((tmptaint >> i) & 1)
2393 				add_taint(i);
2394 		}
2395 	}
2396 
2397 	return err;
2398 }
2399 
2400 struct do_proc_dointvec_minmax_conv_param {
2401 	int *min;
2402 	int *max;
2403 };
2404 
2405 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2406 					int *valp,
2407 					int write, void *data)
2408 {
2409 	struct do_proc_dointvec_minmax_conv_param *param = data;
2410 	if (write) {
2411 		int val = *negp ? -*lvalp : *lvalp;
2412 		if ((param->min && *param->min > val) ||
2413 		    (param->max && *param->max < val))
2414 			return -EINVAL;
2415 		*valp = val;
2416 	} else {
2417 		int val = *valp;
2418 		if (val < 0) {
2419 			*negp = true;
2420 			*lvalp = (unsigned long)-val;
2421 		} else {
2422 			*negp = false;
2423 			*lvalp = (unsigned long)val;
2424 		}
2425 	}
2426 	return 0;
2427 }
2428 
2429 /**
2430  * proc_dointvec_minmax - read a vector of integers with min/max values
2431  * @table: the sysctl table
2432  * @write: %TRUE if this is a write to the sysctl file
2433  * @buffer: the user buffer
2434  * @lenp: the size of the user buffer
2435  * @ppos: file position
2436  *
2437  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2438  * values from/to the user buffer, treated as an ASCII string.
2439  *
2440  * This routine will ensure the values are within the range specified by
2441  * table->extra1 (min) and table->extra2 (max).
2442  *
2443  * Returns 0 on success.
2444  */
2445 int proc_dointvec_minmax(struct ctl_table *table, int write,
2446 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2447 {
2448 	struct do_proc_dointvec_minmax_conv_param param = {
2449 		.min = (int *) table->extra1,
2450 		.max = (int *) table->extra2,
2451 	};
2452 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2453 				do_proc_dointvec_minmax_conv, &param);
2454 }
2455 
2456 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2457 				     void __user *buffer,
2458 				     size_t *lenp, loff_t *ppos,
2459 				     unsigned long convmul,
2460 				     unsigned long convdiv)
2461 {
2462 	unsigned long *i, *min, *max;
2463 	int vleft, first = 1, err = 0;
2464 	unsigned long page = 0;
2465 	size_t left;
2466 	char *kbuf;
2467 
2468 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2469 		*lenp = 0;
2470 		return 0;
2471 	}
2472 
2473 	i = (unsigned long *) data;
2474 	min = (unsigned long *) table->extra1;
2475 	max = (unsigned long *) table->extra2;
2476 	vleft = table->maxlen / sizeof(unsigned long);
2477 	left = *lenp;
2478 
2479 	if (write) {
2480 		if (left > PAGE_SIZE - 1)
2481 			left = PAGE_SIZE - 1;
2482 		page = __get_free_page(GFP_TEMPORARY);
2483 		kbuf = (char *) page;
2484 		if (!kbuf)
2485 			return -ENOMEM;
2486 		if (copy_from_user(kbuf, buffer, left)) {
2487 			err = -EFAULT;
2488 			goto free;
2489 		}
2490 		kbuf[left] = 0;
2491 	}
2492 
2493 	for (; left && vleft--; i++, first = 0) {
2494 		unsigned long val;
2495 
2496 		if (write) {
2497 			bool neg;
2498 
2499 			left -= proc_skip_spaces(&kbuf);
2500 
2501 			err = proc_get_long(&kbuf, &left, &val, &neg,
2502 					     proc_wspace_sep,
2503 					     sizeof(proc_wspace_sep), NULL);
2504 			if (err)
2505 				break;
2506 			if (neg)
2507 				continue;
2508 			if ((min && val < *min) || (max && val > *max))
2509 				continue;
2510 			*i = val;
2511 		} else {
2512 			val = convdiv * (*i) / convmul;
2513 			if (!first)
2514 				err = proc_put_char(&buffer, &left, '\t');
2515 			err = proc_put_long(&buffer, &left, val, false);
2516 			if (err)
2517 				break;
2518 		}
2519 	}
2520 
2521 	if (!write && !first && left && !err)
2522 		err = proc_put_char(&buffer, &left, '\n');
2523 	if (write && !err)
2524 		left -= proc_skip_spaces(&kbuf);
2525 free:
2526 	if (write) {
2527 		free_page(page);
2528 		if (first)
2529 			return err ? : -EINVAL;
2530 	}
2531 	*lenp -= left;
2532 	*ppos += *lenp;
2533 	return err;
2534 }
2535 
2536 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2537 				     void __user *buffer,
2538 				     size_t *lenp, loff_t *ppos,
2539 				     unsigned long convmul,
2540 				     unsigned long convdiv)
2541 {
2542 	return __do_proc_doulongvec_minmax(table->data, table, write,
2543 			buffer, lenp, ppos, convmul, convdiv);
2544 }
2545 
2546 /**
2547  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2548  * @table: the sysctl table
2549  * @write: %TRUE if this is a write to the sysctl file
2550  * @buffer: the user buffer
2551  * @lenp: the size of the user buffer
2552  * @ppos: file position
2553  *
2554  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2555  * values from/to the user buffer, treated as an ASCII string.
2556  *
2557  * This routine will ensure the values are within the range specified by
2558  * table->extra1 (min) and table->extra2 (max).
2559  *
2560  * Returns 0 on success.
2561  */
2562 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2563 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2564 {
2565     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2566 }
2567 
2568 /**
2569  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2570  * @table: the sysctl table
2571  * @write: %TRUE if this is a write to the sysctl file
2572  * @buffer: the user buffer
2573  * @lenp: the size of the user buffer
2574  * @ppos: file position
2575  *
2576  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2577  * values from/to the user buffer, treated as an ASCII string. The values
2578  * are treated as milliseconds, and converted to jiffies when they are stored.
2579  *
2580  * This routine will ensure the values are within the range specified by
2581  * table->extra1 (min) and table->extra2 (max).
2582  *
2583  * Returns 0 on success.
2584  */
2585 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2586 				      void __user *buffer,
2587 				      size_t *lenp, loff_t *ppos)
2588 {
2589     return do_proc_doulongvec_minmax(table, write, buffer,
2590 				     lenp, ppos, HZ, 1000l);
2591 }
2592 
2593 
2594 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2595 					 int *valp,
2596 					 int write, void *data)
2597 {
2598 	if (write) {
2599 		if (*lvalp > LONG_MAX / HZ)
2600 			return 1;
2601 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2602 	} else {
2603 		int val = *valp;
2604 		unsigned long lval;
2605 		if (val < 0) {
2606 			*negp = true;
2607 			lval = (unsigned long)-val;
2608 		} else {
2609 			*negp = false;
2610 			lval = (unsigned long)val;
2611 		}
2612 		*lvalp = lval / HZ;
2613 	}
2614 	return 0;
2615 }
2616 
2617 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2618 						int *valp,
2619 						int write, void *data)
2620 {
2621 	if (write) {
2622 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2623 			return 1;
2624 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2625 	} else {
2626 		int val = *valp;
2627 		unsigned long lval;
2628 		if (val < 0) {
2629 			*negp = true;
2630 			lval = (unsigned long)-val;
2631 		} else {
2632 			*negp = false;
2633 			lval = (unsigned long)val;
2634 		}
2635 		*lvalp = jiffies_to_clock_t(lval);
2636 	}
2637 	return 0;
2638 }
2639 
2640 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2641 					    int *valp,
2642 					    int write, void *data)
2643 {
2644 	if (write) {
2645 		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
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 = jiffies_to_msecs(lval);
2657 	}
2658 	return 0;
2659 }
2660 
2661 /**
2662  * proc_dointvec_jiffies - read a vector of integers as seconds
2663  * @table: the sysctl table
2664  * @write: %TRUE if this is a write to the sysctl file
2665  * @buffer: the user buffer
2666  * @lenp: the size of the user buffer
2667  * @ppos: file position
2668  *
2669  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2670  * values from/to the user buffer, treated as an ASCII string.
2671  * The values read are assumed to be in seconds, and are converted into
2672  * jiffies.
2673  *
2674  * Returns 0 on success.
2675  */
2676 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2677 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2678 {
2679     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2680 		    	    do_proc_dointvec_jiffies_conv,NULL);
2681 }
2682 
2683 /**
2684  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2685  * @table: the sysctl table
2686  * @write: %TRUE if this is a write to the sysctl file
2687  * @buffer: the user buffer
2688  * @lenp: the size of the user buffer
2689  * @ppos: pointer to the file position
2690  *
2691  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2692  * values from/to the user buffer, treated as an ASCII string.
2693  * The values read are assumed to be in 1/USER_HZ seconds, and
2694  * are converted into jiffies.
2695  *
2696  * Returns 0 on success.
2697  */
2698 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2699 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2700 {
2701     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2702 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2703 }
2704 
2705 /**
2706  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
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  * @ppos: the current position in the file
2713  *
2714  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715  * values from/to the user buffer, treated as an ASCII string.
2716  * The values read are assumed to be in 1/1000 seconds, and
2717  * are converted into jiffies.
2718  *
2719  * Returns 0 on success.
2720  */
2721 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2722 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2723 {
2724 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2725 				do_proc_dointvec_ms_jiffies_conv, NULL);
2726 }
2727 
2728 static int proc_do_cad_pid(struct ctl_table *table, int write,
2729 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2730 {
2731 	struct pid *new_pid;
2732 	pid_t tmp;
2733 	int r;
2734 
2735 	tmp = pid_vnr(cad_pid);
2736 
2737 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2738 			       lenp, ppos, NULL, NULL);
2739 	if (r || !write)
2740 		return r;
2741 
2742 	new_pid = find_get_pid(tmp);
2743 	if (!new_pid)
2744 		return -ESRCH;
2745 
2746 	put_pid(xchg(&cad_pid, new_pid));
2747 	return 0;
2748 }
2749 
2750 /**
2751  * proc_do_large_bitmap - read/write from/to a large bitmap
2752  * @table: the sysctl table
2753  * @write: %TRUE if this is a write to the sysctl file
2754  * @buffer: the user buffer
2755  * @lenp: the size of the user buffer
2756  * @ppos: file position
2757  *
2758  * The bitmap is stored at table->data and the bitmap length (in bits)
2759  * in table->maxlen.
2760  *
2761  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2762  * large bitmaps may be represented in a compact manner. Writing into
2763  * the file will clear the bitmap then update it with the given input.
2764  *
2765  * Returns 0 on success.
2766  */
2767 int proc_do_large_bitmap(struct ctl_table *table, int write,
2768 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2769 {
2770 	int err = 0;
2771 	bool first = 1;
2772 	size_t left = *lenp;
2773 	unsigned long bitmap_len = table->maxlen;
2774 	unsigned long *bitmap = (unsigned long *) table->data;
2775 	unsigned long *tmp_bitmap = NULL;
2776 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2777 
2778 	if (!bitmap_len || !left || (*ppos && !write)) {
2779 		*lenp = 0;
2780 		return 0;
2781 	}
2782 
2783 	if (write) {
2784 		unsigned long page = 0;
2785 		char *kbuf;
2786 
2787 		if (left > PAGE_SIZE - 1)
2788 			left = PAGE_SIZE - 1;
2789 
2790 		page = __get_free_page(GFP_TEMPORARY);
2791 		kbuf = (char *) page;
2792 		if (!kbuf)
2793 			return -ENOMEM;
2794 		if (copy_from_user(kbuf, buffer, left)) {
2795 			free_page(page);
2796 			return -EFAULT;
2797                 }
2798 		kbuf[left] = 0;
2799 
2800 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2801 				     GFP_KERNEL);
2802 		if (!tmp_bitmap) {
2803 			free_page(page);
2804 			return -ENOMEM;
2805 		}
2806 		proc_skip_char(&kbuf, &left, '\n');
2807 		while (!err && left) {
2808 			unsigned long val_a, val_b;
2809 			bool neg;
2810 
2811 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2812 					     sizeof(tr_a), &c);
2813 			if (err)
2814 				break;
2815 			if (val_a >= bitmap_len || neg) {
2816 				err = -EINVAL;
2817 				break;
2818 			}
2819 
2820 			val_b = val_a;
2821 			if (left) {
2822 				kbuf++;
2823 				left--;
2824 			}
2825 
2826 			if (c == '-') {
2827 				err = proc_get_long(&kbuf, &left, &val_b,
2828 						     &neg, tr_b, sizeof(tr_b),
2829 						     &c);
2830 				if (err)
2831 					break;
2832 				if (val_b >= bitmap_len || neg ||
2833 				    val_a > val_b) {
2834 					err = -EINVAL;
2835 					break;
2836 				}
2837 				if (left) {
2838 					kbuf++;
2839 					left--;
2840 				}
2841 			}
2842 
2843 			while (val_a <= val_b)
2844 				set_bit(val_a++, tmp_bitmap);
2845 
2846 			first = 0;
2847 			proc_skip_char(&kbuf, &left, '\n');
2848 		}
2849 		free_page(page);
2850 	} else {
2851 		unsigned long bit_a, bit_b = 0;
2852 
2853 		while (left) {
2854 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2855 			if (bit_a >= bitmap_len)
2856 				break;
2857 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2858 						   bit_a + 1) - 1;
2859 
2860 			if (!first) {
2861 				err = proc_put_char(&buffer, &left, ',');
2862 				if (err)
2863 					break;
2864 			}
2865 			err = proc_put_long(&buffer, &left, bit_a, false);
2866 			if (err)
2867 				break;
2868 			if (bit_a != bit_b) {
2869 				err = proc_put_char(&buffer, &left, '-');
2870 				if (err)
2871 					break;
2872 				err = proc_put_long(&buffer, &left, bit_b, false);
2873 				if (err)
2874 					break;
2875 			}
2876 
2877 			first = 0; bit_b++;
2878 		}
2879 		if (!err)
2880 			err = proc_put_char(&buffer, &left, '\n');
2881 	}
2882 
2883 	if (!err) {
2884 		if (write) {
2885 			if (*ppos)
2886 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2887 			else
2888 				memcpy(bitmap, tmp_bitmap,
2889 					BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2890 		}
2891 		kfree(tmp_bitmap);
2892 		*lenp -= left;
2893 		*ppos += *lenp;
2894 		return 0;
2895 	} else {
2896 		kfree(tmp_bitmap);
2897 		return err;
2898 	}
2899 }
2900 
2901 #else /* CONFIG_PROC_SYSCTL */
2902 
2903 int proc_dostring(struct ctl_table *table, int write,
2904 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2905 {
2906 	return -ENOSYS;
2907 }
2908 
2909 int proc_dointvec(struct ctl_table *table, int write,
2910 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2911 {
2912 	return -ENOSYS;
2913 }
2914 
2915 int proc_dointvec_minmax(struct ctl_table *table, int write,
2916 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2917 {
2918 	return -ENOSYS;
2919 }
2920 
2921 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2922 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2923 {
2924 	return -ENOSYS;
2925 }
2926 
2927 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2928 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2929 {
2930 	return -ENOSYS;
2931 }
2932 
2933 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2934 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2935 {
2936 	return -ENOSYS;
2937 }
2938 
2939 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2940 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2941 {
2942 	return -ENOSYS;
2943 }
2944 
2945 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2946 				      void __user *buffer,
2947 				      size_t *lenp, loff_t *ppos)
2948 {
2949     return -ENOSYS;
2950 }
2951 
2952 
2953 #endif /* CONFIG_PROC_SYSCTL */
2954 
2955 /*
2956  * No sense putting this after each symbol definition, twice,
2957  * exception granted :-)
2958  */
2959 EXPORT_SYMBOL(proc_dointvec);
2960 EXPORT_SYMBOL(proc_dointvec_jiffies);
2961 EXPORT_SYMBOL(proc_dointvec_minmax);
2962 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2963 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2964 EXPORT_SYMBOL(proc_dostring);
2965 EXPORT_SYMBOL(proc_doulongvec_minmax);
2966 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2967 EXPORT_SYMBOL(register_sysctl_table);
2968 EXPORT_SYMBOL(register_sysctl_paths);
2969 EXPORT_SYMBOL(unregister_sysctl_table);
2970