xref: /openbmc/linux/kernel/sysctl.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 void sysctl_head_put(struct ctl_table_header *head)
1571 {
1572 	spin_lock(&sysctl_lock);
1573 	if (!--head->count)
1574 		kfree(head);
1575 	spin_unlock(&sysctl_lock);
1576 }
1577 
1578 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1579 {
1580 	if (!head)
1581 		BUG();
1582 	spin_lock(&sysctl_lock);
1583 	if (!use_table(head))
1584 		head = ERR_PTR(-ENOENT);
1585 	spin_unlock(&sysctl_lock);
1586 	return head;
1587 }
1588 
1589 void sysctl_head_finish(struct ctl_table_header *head)
1590 {
1591 	if (!head)
1592 		return;
1593 	spin_lock(&sysctl_lock);
1594 	unuse_table(head);
1595 	spin_unlock(&sysctl_lock);
1596 }
1597 
1598 static struct ctl_table_set *
1599 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1600 {
1601 	struct ctl_table_set *set = &root->default_set;
1602 	if (root->lookup)
1603 		set = root->lookup(root, namespaces);
1604 	return set;
1605 }
1606 
1607 static struct list_head *
1608 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1609 {
1610 	struct ctl_table_set *set = lookup_header_set(root, namespaces);
1611 	return &set->list;
1612 }
1613 
1614 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1615 					    struct ctl_table_header *prev)
1616 {
1617 	struct ctl_table_root *root;
1618 	struct list_head *header_list;
1619 	struct ctl_table_header *head;
1620 	struct list_head *tmp;
1621 
1622 	spin_lock(&sysctl_lock);
1623 	if (prev) {
1624 		head = prev;
1625 		tmp = &prev->ctl_entry;
1626 		unuse_table(prev);
1627 		goto next;
1628 	}
1629 	tmp = &root_table_header.ctl_entry;
1630 	for (;;) {
1631 		head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1632 
1633 		if (!use_table(head))
1634 			goto next;
1635 		spin_unlock(&sysctl_lock);
1636 		return head;
1637 	next:
1638 		root = head->root;
1639 		tmp = tmp->next;
1640 		header_list = lookup_header_list(root, namespaces);
1641 		if (tmp != header_list)
1642 			continue;
1643 
1644 		do {
1645 			root = list_entry(root->root_list.next,
1646 					struct ctl_table_root, root_list);
1647 			if (root == &sysctl_table_root)
1648 				goto out;
1649 			header_list = lookup_header_list(root, namespaces);
1650 		} while (list_empty(header_list));
1651 		tmp = header_list->next;
1652 	}
1653 out:
1654 	spin_unlock(&sysctl_lock);
1655 	return NULL;
1656 }
1657 
1658 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1659 {
1660 	return __sysctl_head_next(current->nsproxy, prev);
1661 }
1662 
1663 void register_sysctl_root(struct ctl_table_root *root)
1664 {
1665 	spin_lock(&sysctl_lock);
1666 	list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1667 	spin_unlock(&sysctl_lock);
1668 }
1669 
1670 /*
1671  * sysctl_perm does NOT grant the superuser all rights automatically, because
1672  * some sysctl variables are readonly even to root.
1673  */
1674 
1675 static int test_perm(int mode, int op)
1676 {
1677 	if (!current_euid())
1678 		mode >>= 6;
1679 	else if (in_egroup_p(0))
1680 		mode >>= 3;
1681 	if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1682 		return 0;
1683 	return -EACCES;
1684 }
1685 
1686 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1687 {
1688 	int error;
1689 	int mode;
1690 
1691 	error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1692 	if (error)
1693 		return error;
1694 
1695 	if (root->permissions)
1696 		mode = root->permissions(root, current->nsproxy, table);
1697 	else
1698 		mode = table->mode;
1699 
1700 	return test_perm(mode, op);
1701 }
1702 
1703 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1704 {
1705 	for (; table->procname; table++) {
1706 		table->parent = parent;
1707 		if (table->child)
1708 			sysctl_set_parent(table, table->child);
1709 	}
1710 }
1711 
1712 static __init int sysctl_init(void)
1713 {
1714 	sysctl_set_parent(NULL, root_table);
1715 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1716 	sysctl_check_table(current->nsproxy, root_table);
1717 #endif
1718 	return 0;
1719 }
1720 
1721 core_initcall(sysctl_init);
1722 
1723 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1724 				      struct ctl_table *table)
1725 {
1726 	struct ctl_table *p;
1727 	const char *s = branch->procname;
1728 
1729 	/* branch should have named subdirectory as its first element */
1730 	if (!s || !branch->child)
1731 		return NULL;
1732 
1733 	/* ... and nothing else */
1734 	if (branch[1].procname)
1735 		return NULL;
1736 
1737 	/* table should contain subdirectory with the same name */
1738 	for (p = table; p->procname; p++) {
1739 		if (!p->child)
1740 			continue;
1741 		if (p->procname && strcmp(p->procname, s) == 0)
1742 			return p;
1743 	}
1744 	return NULL;
1745 }
1746 
1747 /* see if attaching q to p would be an improvement */
1748 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1749 {
1750 	struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1751 	struct ctl_table *next;
1752 	int is_better = 0;
1753 	int not_in_parent = !p->attached_by;
1754 
1755 	while ((next = is_branch_in(by, to)) != NULL) {
1756 		if (by == q->attached_by)
1757 			is_better = 1;
1758 		if (to == p->attached_by)
1759 			not_in_parent = 1;
1760 		by = by->child;
1761 		to = next->child;
1762 	}
1763 
1764 	if (is_better && not_in_parent) {
1765 		q->attached_by = by;
1766 		q->attached_to = to;
1767 		q->parent = p;
1768 	}
1769 }
1770 
1771 /**
1772  * __register_sysctl_paths - register a sysctl hierarchy
1773  * @root: List of sysctl headers to register on
1774  * @namespaces: Data to compute which lists of sysctl entries are visible
1775  * @path: The path to the directory the sysctl table is in.
1776  * @table: the top-level table structure
1777  *
1778  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1779  * array. A completely 0 filled entry terminates the table.
1780  *
1781  * The members of the &struct ctl_table structure are used as follows:
1782  *
1783  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1784  *            enter a sysctl file
1785  *
1786  * data - a pointer to data for use by proc_handler
1787  *
1788  * maxlen - the maximum size in bytes of the data
1789  *
1790  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1791  *
1792  * child - a pointer to the child sysctl table if this entry is a directory, or
1793  *         %NULL.
1794  *
1795  * proc_handler - the text handler routine (described below)
1796  *
1797  * de - for internal use by the sysctl routines
1798  *
1799  * extra1, extra2 - extra pointers usable by the proc handler routines
1800  *
1801  * Leaf nodes in the sysctl tree will be represented by a single file
1802  * under /proc; non-leaf nodes will be represented by directories.
1803  *
1804  * sysctl(2) can automatically manage read and write requests through
1805  * the sysctl table.  The data and maxlen fields of the ctl_table
1806  * struct enable minimal validation of the values being written to be
1807  * performed, and the mode field allows minimal authentication.
1808  *
1809  * There must be a proc_handler routine for any terminal nodes
1810  * mirrored under /proc/sys (non-terminals are handled by a built-in
1811  * directory handler).  Several default handlers are available to
1812  * cover common cases -
1813  *
1814  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1815  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1816  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1817  *
1818  * It is the handler's job to read the input buffer from user memory
1819  * and process it. The handler should return 0 on success.
1820  *
1821  * This routine returns %NULL on a failure to register, and a pointer
1822  * to the table header on success.
1823  */
1824 struct ctl_table_header *__register_sysctl_paths(
1825 	struct ctl_table_root *root,
1826 	struct nsproxy *namespaces,
1827 	const struct ctl_path *path, struct ctl_table *table)
1828 {
1829 	struct ctl_table_header *header;
1830 	struct ctl_table *new, **prevp;
1831 	unsigned int n, npath;
1832 	struct ctl_table_set *set;
1833 
1834 	/* Count the path components */
1835 	for (npath = 0; path[npath].procname; ++npath)
1836 		;
1837 
1838 	/*
1839 	 * For each path component, allocate a 2-element ctl_table array.
1840 	 * The first array element will be filled with the sysctl entry
1841 	 * for this, the second will be the sentinel (procname == 0).
1842 	 *
1843 	 * We allocate everything in one go so that we don't have to
1844 	 * worry about freeing additional memory in unregister_sysctl_table.
1845 	 */
1846 	header = kzalloc(sizeof(struct ctl_table_header) +
1847 			 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1848 	if (!header)
1849 		return NULL;
1850 
1851 	new = (struct ctl_table *) (header + 1);
1852 
1853 	/* Now connect the dots */
1854 	prevp = &header->ctl_table;
1855 	for (n = 0; n < npath; ++n, ++path) {
1856 		/* Copy the procname */
1857 		new->procname = path->procname;
1858 		new->mode     = 0555;
1859 
1860 		*prevp = new;
1861 		prevp = &new->child;
1862 
1863 		new += 2;
1864 	}
1865 	*prevp = table;
1866 	header->ctl_table_arg = table;
1867 
1868 	INIT_LIST_HEAD(&header->ctl_entry);
1869 	header->used = 0;
1870 	header->unregistering = NULL;
1871 	header->root = root;
1872 	sysctl_set_parent(NULL, header->ctl_table);
1873 	header->count = 1;
1874 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1875 	if (sysctl_check_table(namespaces, header->ctl_table)) {
1876 		kfree(header);
1877 		return NULL;
1878 	}
1879 #endif
1880 	spin_lock(&sysctl_lock);
1881 	header->set = lookup_header_set(root, namespaces);
1882 	header->attached_by = header->ctl_table;
1883 	header->attached_to = root_table;
1884 	header->parent = &root_table_header;
1885 	for (set = header->set; set; set = set->parent) {
1886 		struct ctl_table_header *p;
1887 		list_for_each_entry(p, &set->list, ctl_entry) {
1888 			if (p->unregistering)
1889 				continue;
1890 			try_attach(p, header);
1891 		}
1892 	}
1893 	header->parent->count++;
1894 	list_add_tail(&header->ctl_entry, &header->set->list);
1895 	spin_unlock(&sysctl_lock);
1896 
1897 	return header;
1898 }
1899 
1900 /**
1901  * register_sysctl_table_path - register a sysctl table hierarchy
1902  * @path: The path to the directory the sysctl table is in.
1903  * @table: the top-level table structure
1904  *
1905  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1906  * array. A completely 0 filled entry terminates the table.
1907  *
1908  * See __register_sysctl_paths for more details.
1909  */
1910 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1911 						struct ctl_table *table)
1912 {
1913 	return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1914 					path, table);
1915 }
1916 
1917 /**
1918  * register_sysctl_table - register a sysctl table hierarchy
1919  * @table: the top-level table structure
1920  *
1921  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1922  * array. A completely 0 filled entry terminates the table.
1923  *
1924  * See register_sysctl_paths for more details.
1925  */
1926 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1927 {
1928 	static const struct ctl_path null_path[] = { {} };
1929 
1930 	return register_sysctl_paths(null_path, table);
1931 }
1932 
1933 /**
1934  * unregister_sysctl_table - unregister a sysctl table hierarchy
1935  * @header: the header returned from register_sysctl_table
1936  *
1937  * Unregisters the sysctl table and all children. proc entries may not
1938  * actually be removed until they are no longer used by anyone.
1939  */
1940 void unregister_sysctl_table(struct ctl_table_header * header)
1941 {
1942 	might_sleep();
1943 
1944 	if (header == NULL)
1945 		return;
1946 
1947 	spin_lock(&sysctl_lock);
1948 	start_unregistering(header);
1949 	if (!--header->parent->count) {
1950 		WARN_ON(1);
1951 		kfree(header->parent);
1952 	}
1953 	if (!--header->count)
1954 		kfree(header);
1955 	spin_unlock(&sysctl_lock);
1956 }
1957 
1958 int sysctl_is_seen(struct ctl_table_header *p)
1959 {
1960 	struct ctl_table_set *set = p->set;
1961 	int res;
1962 	spin_lock(&sysctl_lock);
1963 	if (p->unregistering)
1964 		res = 0;
1965 	else if (!set->is_seen)
1966 		res = 1;
1967 	else
1968 		res = set->is_seen(set);
1969 	spin_unlock(&sysctl_lock);
1970 	return res;
1971 }
1972 
1973 void setup_sysctl_set(struct ctl_table_set *p,
1974 	struct ctl_table_set *parent,
1975 	int (*is_seen)(struct ctl_table_set *))
1976 {
1977 	INIT_LIST_HEAD(&p->list);
1978 	p->parent = parent ? parent : &sysctl_table_root.default_set;
1979 	p->is_seen = is_seen;
1980 }
1981 
1982 #else /* !CONFIG_SYSCTL */
1983 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1984 {
1985 	return NULL;
1986 }
1987 
1988 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1989 						    struct ctl_table *table)
1990 {
1991 	return NULL;
1992 }
1993 
1994 void unregister_sysctl_table(struct ctl_table_header * table)
1995 {
1996 }
1997 
1998 void setup_sysctl_set(struct ctl_table_set *p,
1999 	struct ctl_table_set *parent,
2000 	int (*is_seen)(struct ctl_table_set *))
2001 {
2002 }
2003 
2004 void sysctl_head_put(struct ctl_table_header *head)
2005 {
2006 }
2007 
2008 #endif /* CONFIG_SYSCTL */
2009 
2010 /*
2011  * /proc/sys support
2012  */
2013 
2014 #ifdef CONFIG_PROC_SYSCTL
2015 
2016 static int _proc_do_string(void* data, int maxlen, int write,
2017 			   void __user *buffer,
2018 			   size_t *lenp, loff_t *ppos)
2019 {
2020 	size_t len;
2021 	char __user *p;
2022 	char c;
2023 
2024 	if (!data || !maxlen || !*lenp) {
2025 		*lenp = 0;
2026 		return 0;
2027 	}
2028 
2029 	if (write) {
2030 		len = 0;
2031 		p = buffer;
2032 		while (len < *lenp) {
2033 			if (get_user(c, p++))
2034 				return -EFAULT;
2035 			if (c == 0 || c == '\n')
2036 				break;
2037 			len++;
2038 		}
2039 		if (len >= maxlen)
2040 			len = maxlen-1;
2041 		if(copy_from_user(data, buffer, len))
2042 			return -EFAULT;
2043 		((char *) data)[len] = 0;
2044 		*ppos += *lenp;
2045 	} else {
2046 		len = strlen(data);
2047 		if (len > maxlen)
2048 			len = maxlen;
2049 
2050 		if (*ppos > len) {
2051 			*lenp = 0;
2052 			return 0;
2053 		}
2054 
2055 		data += *ppos;
2056 		len  -= *ppos;
2057 
2058 		if (len > *lenp)
2059 			len = *lenp;
2060 		if (len)
2061 			if(copy_to_user(buffer, data, len))
2062 				return -EFAULT;
2063 		if (len < *lenp) {
2064 			if(put_user('\n', ((char __user *) buffer) + len))
2065 				return -EFAULT;
2066 			len++;
2067 		}
2068 		*lenp = len;
2069 		*ppos += len;
2070 	}
2071 	return 0;
2072 }
2073 
2074 /**
2075  * proc_dostring - read a string sysctl
2076  * @table: the sysctl table
2077  * @write: %TRUE if this is a write to the sysctl file
2078  * @buffer: the user buffer
2079  * @lenp: the size of the user buffer
2080  * @ppos: file position
2081  *
2082  * Reads/writes a string from/to the user buffer. If the kernel
2083  * buffer provided is not large enough to hold the string, the
2084  * string is truncated. The copied string is %NULL-terminated.
2085  * If the string is being read by the user process, it is copied
2086  * and a newline '\n' is added. It is truncated if the buffer is
2087  * not large enough.
2088  *
2089  * Returns 0 on success.
2090  */
2091 int proc_dostring(struct ctl_table *table, int write,
2092 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2093 {
2094 	return _proc_do_string(table->data, table->maxlen, write,
2095 			       buffer, lenp, ppos);
2096 }
2097 
2098 static size_t proc_skip_spaces(char **buf)
2099 {
2100 	size_t ret;
2101 	char *tmp = skip_spaces(*buf);
2102 	ret = tmp - *buf;
2103 	*buf = tmp;
2104 	return ret;
2105 }
2106 
2107 static void proc_skip_char(char **buf, size_t *size, const char v)
2108 {
2109 	while (*size) {
2110 		if (**buf != v)
2111 			break;
2112 		(*size)--;
2113 		(*buf)++;
2114 	}
2115 }
2116 
2117 #define TMPBUFLEN 22
2118 /**
2119  * proc_get_long - reads an ASCII formatted integer from a user buffer
2120  *
2121  * @buf: a kernel buffer
2122  * @size: size of the kernel buffer
2123  * @val: this is where the number will be stored
2124  * @neg: set to %TRUE if number is negative
2125  * @perm_tr: a vector which contains the allowed trailers
2126  * @perm_tr_len: size of the perm_tr vector
2127  * @tr: pointer to store the trailer character
2128  *
2129  * In case of success %0 is returned and @buf and @size are updated with
2130  * the amount of bytes read. If @tr is non-NULL and a trailing
2131  * character exists (size is non-zero after returning from this
2132  * function), @tr is updated with the trailing character.
2133  */
2134 static int proc_get_long(char **buf, size_t *size,
2135 			  unsigned long *val, bool *neg,
2136 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2137 {
2138 	int len;
2139 	char *p, tmp[TMPBUFLEN];
2140 
2141 	if (!*size)
2142 		return -EINVAL;
2143 
2144 	len = *size;
2145 	if (len > TMPBUFLEN - 1)
2146 		len = TMPBUFLEN - 1;
2147 
2148 	memcpy(tmp, *buf, len);
2149 
2150 	tmp[len] = 0;
2151 	p = tmp;
2152 	if (*p == '-' && *size > 1) {
2153 		*neg = true;
2154 		p++;
2155 	} else
2156 		*neg = false;
2157 	if (!isdigit(*p))
2158 		return -EINVAL;
2159 
2160 	*val = simple_strtoul(p, &p, 0);
2161 
2162 	len = p - tmp;
2163 
2164 	/* We don't know if the next char is whitespace thus we may accept
2165 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2166 	 * (e.g. 123...1). So lets not allow such large numbers. */
2167 	if (len == TMPBUFLEN - 1)
2168 		return -EINVAL;
2169 
2170 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2171 		return -EINVAL;
2172 
2173 	if (tr && (len < *size))
2174 		*tr = *p;
2175 
2176 	*buf += len;
2177 	*size -= len;
2178 
2179 	return 0;
2180 }
2181 
2182 /**
2183  * proc_put_long - converts an integer to a decimal ASCII formatted string
2184  *
2185  * @buf: the user buffer
2186  * @size: the size of the user buffer
2187  * @val: the integer to be converted
2188  * @neg: sign of the number, %TRUE for negative
2189  *
2190  * In case of success %0 is returned and @buf and @size are updated with
2191  * the amount of bytes written.
2192  */
2193 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2194 			  bool neg)
2195 {
2196 	int len;
2197 	char tmp[TMPBUFLEN], *p = tmp;
2198 
2199 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2200 	len = strlen(tmp);
2201 	if (len > *size)
2202 		len = *size;
2203 	if (copy_to_user(*buf, tmp, len))
2204 		return -EFAULT;
2205 	*size -= len;
2206 	*buf += len;
2207 	return 0;
2208 }
2209 #undef TMPBUFLEN
2210 
2211 static int proc_put_char(void __user **buf, size_t *size, char c)
2212 {
2213 	if (*size) {
2214 		char __user **buffer = (char __user **)buf;
2215 		if (put_user(c, *buffer))
2216 			return -EFAULT;
2217 		(*size)--, (*buffer)++;
2218 		*buf = *buffer;
2219 	}
2220 	return 0;
2221 }
2222 
2223 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2224 				 int *valp,
2225 				 int write, void *data)
2226 {
2227 	if (write) {
2228 		*valp = *negp ? -*lvalp : *lvalp;
2229 	} else {
2230 		int val = *valp;
2231 		if (val < 0) {
2232 			*negp = true;
2233 			*lvalp = (unsigned long)-val;
2234 		} else {
2235 			*negp = false;
2236 			*lvalp = (unsigned long)val;
2237 		}
2238 	}
2239 	return 0;
2240 }
2241 
2242 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2243 
2244 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2245 		  int write, void __user *buffer,
2246 		  size_t *lenp, loff_t *ppos,
2247 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2248 			      int write, void *data),
2249 		  void *data)
2250 {
2251 	int *i, vleft, first = 1, err = 0;
2252 	unsigned long page = 0;
2253 	size_t left;
2254 	char *kbuf;
2255 
2256 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2257 		*lenp = 0;
2258 		return 0;
2259 	}
2260 
2261 	i = (int *) tbl_data;
2262 	vleft = table->maxlen / sizeof(*i);
2263 	left = *lenp;
2264 
2265 	if (!conv)
2266 		conv = do_proc_dointvec_conv;
2267 
2268 	if (write) {
2269 		if (left > PAGE_SIZE - 1)
2270 			left = PAGE_SIZE - 1;
2271 		page = __get_free_page(GFP_TEMPORARY);
2272 		kbuf = (char *) page;
2273 		if (!kbuf)
2274 			return -ENOMEM;
2275 		if (copy_from_user(kbuf, buffer, left)) {
2276 			err = -EFAULT;
2277 			goto free;
2278 		}
2279 		kbuf[left] = 0;
2280 	}
2281 
2282 	for (; left && vleft--; i++, first=0) {
2283 		unsigned long lval;
2284 		bool neg;
2285 
2286 		if (write) {
2287 			left -= proc_skip_spaces(&kbuf);
2288 
2289 			if (!left)
2290 				break;
2291 			err = proc_get_long(&kbuf, &left, &lval, &neg,
2292 					     proc_wspace_sep,
2293 					     sizeof(proc_wspace_sep), NULL);
2294 			if (err)
2295 				break;
2296 			if (conv(&neg, &lval, i, 1, data)) {
2297 				err = -EINVAL;
2298 				break;
2299 			}
2300 		} else {
2301 			if (conv(&neg, &lval, i, 0, data)) {
2302 				err = -EINVAL;
2303 				break;
2304 			}
2305 			if (!first)
2306 				err = proc_put_char(&buffer, &left, '\t');
2307 			if (err)
2308 				break;
2309 			err = proc_put_long(&buffer, &left, lval, neg);
2310 			if (err)
2311 				break;
2312 		}
2313 	}
2314 
2315 	if (!write && !first && left && !err)
2316 		err = proc_put_char(&buffer, &left, '\n');
2317 	if (write && !err && left)
2318 		left -= proc_skip_spaces(&kbuf);
2319 free:
2320 	if (write) {
2321 		free_page(page);
2322 		if (first)
2323 			return err ? : -EINVAL;
2324 	}
2325 	*lenp -= left;
2326 	*ppos += *lenp;
2327 	return err;
2328 }
2329 
2330 static int do_proc_dointvec(struct ctl_table *table, int write,
2331 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2332 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2333 			      int write, void *data),
2334 		  void *data)
2335 {
2336 	return __do_proc_dointvec(table->data, table, write,
2337 			buffer, lenp, ppos, conv, data);
2338 }
2339 
2340 /**
2341  * proc_dointvec - read a vector of integers
2342  * @table: the sysctl table
2343  * @write: %TRUE if this is a write to the sysctl file
2344  * @buffer: the user buffer
2345  * @lenp: the size of the user buffer
2346  * @ppos: file position
2347  *
2348  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2349  * values from/to the user buffer, treated as an ASCII string.
2350  *
2351  * Returns 0 on success.
2352  */
2353 int proc_dointvec(struct ctl_table *table, int write,
2354 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2355 {
2356     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2357 		    	    NULL,NULL);
2358 }
2359 
2360 /*
2361  * Taint values can only be increased
2362  * This means we can safely use a temporary.
2363  */
2364 static int proc_taint(struct ctl_table *table, int write,
2365 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2366 {
2367 	struct ctl_table t;
2368 	unsigned long tmptaint = get_taint();
2369 	int err;
2370 
2371 	if (write && !capable(CAP_SYS_ADMIN))
2372 		return -EPERM;
2373 
2374 	t = *table;
2375 	t.data = &tmptaint;
2376 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2377 	if (err < 0)
2378 		return err;
2379 
2380 	if (write) {
2381 		/*
2382 		 * Poor man's atomic or. Not worth adding a primitive
2383 		 * to everyone's atomic.h for this
2384 		 */
2385 		int i;
2386 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2387 			if ((tmptaint >> i) & 1)
2388 				add_taint(i);
2389 		}
2390 	}
2391 
2392 	return err;
2393 }
2394 
2395 struct do_proc_dointvec_minmax_conv_param {
2396 	int *min;
2397 	int *max;
2398 };
2399 
2400 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2401 					int *valp,
2402 					int write, void *data)
2403 {
2404 	struct do_proc_dointvec_minmax_conv_param *param = data;
2405 	if (write) {
2406 		int val = *negp ? -*lvalp : *lvalp;
2407 		if ((param->min && *param->min > val) ||
2408 		    (param->max && *param->max < val))
2409 			return -EINVAL;
2410 		*valp = val;
2411 	} else {
2412 		int val = *valp;
2413 		if (val < 0) {
2414 			*negp = true;
2415 			*lvalp = (unsigned long)-val;
2416 		} else {
2417 			*negp = false;
2418 			*lvalp = (unsigned long)val;
2419 		}
2420 	}
2421 	return 0;
2422 }
2423 
2424 /**
2425  * proc_dointvec_minmax - read a vector of integers with min/max values
2426  * @table: the sysctl table
2427  * @write: %TRUE if this is a write to the sysctl file
2428  * @buffer: the user buffer
2429  * @lenp: the size of the user buffer
2430  * @ppos: file position
2431  *
2432  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2433  * values from/to the user buffer, treated as an ASCII string.
2434  *
2435  * This routine will ensure the values are within the range specified by
2436  * table->extra1 (min) and table->extra2 (max).
2437  *
2438  * Returns 0 on success.
2439  */
2440 int proc_dointvec_minmax(struct ctl_table *table, int write,
2441 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2442 {
2443 	struct do_proc_dointvec_minmax_conv_param param = {
2444 		.min = (int *) table->extra1,
2445 		.max = (int *) table->extra2,
2446 	};
2447 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2448 				do_proc_dointvec_minmax_conv, &param);
2449 }
2450 
2451 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2452 				     void __user *buffer,
2453 				     size_t *lenp, loff_t *ppos,
2454 				     unsigned long convmul,
2455 				     unsigned long convdiv)
2456 {
2457 	unsigned long *i, *min, *max;
2458 	int vleft, first = 1, err = 0;
2459 	unsigned long page = 0;
2460 	size_t left;
2461 	char *kbuf;
2462 
2463 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2464 		*lenp = 0;
2465 		return 0;
2466 	}
2467 
2468 	i = (unsigned long *) data;
2469 	min = (unsigned long *) table->extra1;
2470 	max = (unsigned long *) table->extra2;
2471 	vleft = table->maxlen / sizeof(unsigned long);
2472 	left = *lenp;
2473 
2474 	if (write) {
2475 		if (left > PAGE_SIZE - 1)
2476 			left = PAGE_SIZE - 1;
2477 		page = __get_free_page(GFP_TEMPORARY);
2478 		kbuf = (char *) page;
2479 		if (!kbuf)
2480 			return -ENOMEM;
2481 		if (copy_from_user(kbuf, buffer, left)) {
2482 			err = -EFAULT;
2483 			goto free;
2484 		}
2485 		kbuf[left] = 0;
2486 	}
2487 
2488 	for (; left && vleft--; i++, first = 0) {
2489 		unsigned long val;
2490 
2491 		if (write) {
2492 			bool neg;
2493 
2494 			left -= proc_skip_spaces(&kbuf);
2495 
2496 			err = proc_get_long(&kbuf, &left, &val, &neg,
2497 					     proc_wspace_sep,
2498 					     sizeof(proc_wspace_sep), NULL);
2499 			if (err)
2500 				break;
2501 			if (neg)
2502 				continue;
2503 			if ((min && val < *min) || (max && val > *max))
2504 				continue;
2505 			*i = val;
2506 		} else {
2507 			val = convdiv * (*i) / convmul;
2508 			if (!first)
2509 				err = proc_put_char(&buffer, &left, '\t');
2510 			err = proc_put_long(&buffer, &left, val, false);
2511 			if (err)
2512 				break;
2513 		}
2514 	}
2515 
2516 	if (!write && !first && left && !err)
2517 		err = proc_put_char(&buffer, &left, '\n');
2518 	if (write && !err)
2519 		left -= proc_skip_spaces(&kbuf);
2520 free:
2521 	if (write) {
2522 		free_page(page);
2523 		if (first)
2524 			return err ? : -EINVAL;
2525 	}
2526 	*lenp -= left;
2527 	*ppos += *lenp;
2528 	return err;
2529 }
2530 
2531 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2532 				     void __user *buffer,
2533 				     size_t *lenp, loff_t *ppos,
2534 				     unsigned long convmul,
2535 				     unsigned long convdiv)
2536 {
2537 	return __do_proc_doulongvec_minmax(table->data, table, write,
2538 			buffer, lenp, ppos, convmul, convdiv);
2539 }
2540 
2541 /**
2542  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2543  * @table: the sysctl table
2544  * @write: %TRUE if this is a write to the sysctl file
2545  * @buffer: the user buffer
2546  * @lenp: the size of the user buffer
2547  * @ppos: file position
2548  *
2549  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2550  * values from/to the user buffer, treated as an ASCII string.
2551  *
2552  * This routine will ensure the values are within the range specified by
2553  * table->extra1 (min) and table->extra2 (max).
2554  *
2555  * Returns 0 on success.
2556  */
2557 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2558 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2559 {
2560     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2561 }
2562 
2563 /**
2564  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2565  * @table: the sysctl table
2566  * @write: %TRUE if this is a write to the sysctl file
2567  * @buffer: the user buffer
2568  * @lenp: the size of the user buffer
2569  * @ppos: file position
2570  *
2571  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2572  * values from/to the user buffer, treated as an ASCII string. The values
2573  * are treated as milliseconds, and converted to jiffies when they are stored.
2574  *
2575  * This routine will ensure the values are within the range specified by
2576  * table->extra1 (min) and table->extra2 (max).
2577  *
2578  * Returns 0 on success.
2579  */
2580 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2581 				      void __user *buffer,
2582 				      size_t *lenp, loff_t *ppos)
2583 {
2584     return do_proc_doulongvec_minmax(table, write, buffer,
2585 				     lenp, ppos, HZ, 1000l);
2586 }
2587 
2588 
2589 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2590 					 int *valp,
2591 					 int write, void *data)
2592 {
2593 	if (write) {
2594 		if (*lvalp > LONG_MAX / HZ)
2595 			return 1;
2596 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2597 	} else {
2598 		int val = *valp;
2599 		unsigned long lval;
2600 		if (val < 0) {
2601 			*negp = true;
2602 			lval = (unsigned long)-val;
2603 		} else {
2604 			*negp = false;
2605 			lval = (unsigned long)val;
2606 		}
2607 		*lvalp = lval / HZ;
2608 	}
2609 	return 0;
2610 }
2611 
2612 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2613 						int *valp,
2614 						int write, void *data)
2615 {
2616 	if (write) {
2617 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2618 			return 1;
2619 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2620 	} else {
2621 		int val = *valp;
2622 		unsigned long lval;
2623 		if (val < 0) {
2624 			*negp = true;
2625 			lval = (unsigned long)-val;
2626 		} else {
2627 			*negp = false;
2628 			lval = (unsigned long)val;
2629 		}
2630 		*lvalp = jiffies_to_clock_t(lval);
2631 	}
2632 	return 0;
2633 }
2634 
2635 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2636 					    int *valp,
2637 					    int write, void *data)
2638 {
2639 	if (write) {
2640 		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2641 	} else {
2642 		int val = *valp;
2643 		unsigned long lval;
2644 		if (val < 0) {
2645 			*negp = true;
2646 			lval = (unsigned long)-val;
2647 		} else {
2648 			*negp = false;
2649 			lval = (unsigned long)val;
2650 		}
2651 		*lvalp = jiffies_to_msecs(lval);
2652 	}
2653 	return 0;
2654 }
2655 
2656 /**
2657  * proc_dointvec_jiffies - read a vector of integers as seconds
2658  * @table: the sysctl table
2659  * @write: %TRUE if this is a write to the sysctl file
2660  * @buffer: the user buffer
2661  * @lenp: the size of the user buffer
2662  * @ppos: file position
2663  *
2664  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2665  * values from/to the user buffer, treated as an ASCII string.
2666  * The values read are assumed to be in seconds, and are converted into
2667  * jiffies.
2668  *
2669  * Returns 0 on success.
2670  */
2671 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2672 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2673 {
2674     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2675 		    	    do_proc_dointvec_jiffies_conv,NULL);
2676 }
2677 
2678 /**
2679  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2680  * @table: the sysctl table
2681  * @write: %TRUE if this is a write to the sysctl file
2682  * @buffer: the user buffer
2683  * @lenp: the size of the user buffer
2684  * @ppos: pointer to the file position
2685  *
2686  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2687  * values from/to the user buffer, treated as an ASCII string.
2688  * The values read are assumed to be in 1/USER_HZ seconds, and
2689  * are converted into jiffies.
2690  *
2691  * Returns 0 on success.
2692  */
2693 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2694 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2695 {
2696     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2697 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2698 }
2699 
2700 /**
2701  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2702  * @table: the sysctl table
2703  * @write: %TRUE if this is a write to the sysctl file
2704  * @buffer: the user buffer
2705  * @lenp: the size of the user buffer
2706  * @ppos: file position
2707  * @ppos: the current position in the file
2708  *
2709  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2710  * values from/to the user buffer, treated as an ASCII string.
2711  * The values read are assumed to be in 1/1000 seconds, and
2712  * are converted into jiffies.
2713  *
2714  * Returns 0 on success.
2715  */
2716 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2717 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2718 {
2719 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2720 				do_proc_dointvec_ms_jiffies_conv, NULL);
2721 }
2722 
2723 static int proc_do_cad_pid(struct ctl_table *table, int write,
2724 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2725 {
2726 	struct pid *new_pid;
2727 	pid_t tmp;
2728 	int r;
2729 
2730 	tmp = pid_vnr(cad_pid);
2731 
2732 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2733 			       lenp, ppos, NULL, NULL);
2734 	if (r || !write)
2735 		return r;
2736 
2737 	new_pid = find_get_pid(tmp);
2738 	if (!new_pid)
2739 		return -ESRCH;
2740 
2741 	put_pid(xchg(&cad_pid, new_pid));
2742 	return 0;
2743 }
2744 
2745 /**
2746  * proc_do_large_bitmap - read/write from/to a large bitmap
2747  * @table: the sysctl table
2748  * @write: %TRUE if this is a write to the sysctl file
2749  * @buffer: the user buffer
2750  * @lenp: the size of the user buffer
2751  * @ppos: file position
2752  *
2753  * The bitmap is stored at table->data and the bitmap length (in bits)
2754  * in table->maxlen.
2755  *
2756  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2757  * large bitmaps may be represented in a compact manner. Writing into
2758  * the file will clear the bitmap then update it with the given input.
2759  *
2760  * Returns 0 on success.
2761  */
2762 int proc_do_large_bitmap(struct ctl_table *table, int write,
2763 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2764 {
2765 	int err = 0;
2766 	bool first = 1;
2767 	size_t left = *lenp;
2768 	unsigned long bitmap_len = table->maxlen;
2769 	unsigned long *bitmap = (unsigned long *) table->data;
2770 	unsigned long *tmp_bitmap = NULL;
2771 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2772 
2773 	if (!bitmap_len || !left || (*ppos && !write)) {
2774 		*lenp = 0;
2775 		return 0;
2776 	}
2777 
2778 	if (write) {
2779 		unsigned long page = 0;
2780 		char *kbuf;
2781 
2782 		if (left > PAGE_SIZE - 1)
2783 			left = PAGE_SIZE - 1;
2784 
2785 		page = __get_free_page(GFP_TEMPORARY);
2786 		kbuf = (char *) page;
2787 		if (!kbuf)
2788 			return -ENOMEM;
2789 		if (copy_from_user(kbuf, buffer, left)) {
2790 			free_page(page);
2791 			return -EFAULT;
2792                 }
2793 		kbuf[left] = 0;
2794 
2795 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2796 				     GFP_KERNEL);
2797 		if (!tmp_bitmap) {
2798 			free_page(page);
2799 			return -ENOMEM;
2800 		}
2801 		proc_skip_char(&kbuf, &left, '\n');
2802 		while (!err && left) {
2803 			unsigned long val_a, val_b;
2804 			bool neg;
2805 
2806 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2807 					     sizeof(tr_a), &c);
2808 			if (err)
2809 				break;
2810 			if (val_a >= bitmap_len || neg) {
2811 				err = -EINVAL;
2812 				break;
2813 			}
2814 
2815 			val_b = val_a;
2816 			if (left) {
2817 				kbuf++;
2818 				left--;
2819 			}
2820 
2821 			if (c == '-') {
2822 				err = proc_get_long(&kbuf, &left, &val_b,
2823 						     &neg, tr_b, sizeof(tr_b),
2824 						     &c);
2825 				if (err)
2826 					break;
2827 				if (val_b >= bitmap_len || neg ||
2828 				    val_a > val_b) {
2829 					err = -EINVAL;
2830 					break;
2831 				}
2832 				if (left) {
2833 					kbuf++;
2834 					left--;
2835 				}
2836 			}
2837 
2838 			while (val_a <= val_b)
2839 				set_bit(val_a++, tmp_bitmap);
2840 
2841 			first = 0;
2842 			proc_skip_char(&kbuf, &left, '\n');
2843 		}
2844 		free_page(page);
2845 	} else {
2846 		unsigned long bit_a, bit_b = 0;
2847 
2848 		while (left) {
2849 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2850 			if (bit_a >= bitmap_len)
2851 				break;
2852 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2853 						   bit_a + 1) - 1;
2854 
2855 			if (!first) {
2856 				err = proc_put_char(&buffer, &left, ',');
2857 				if (err)
2858 					break;
2859 			}
2860 			err = proc_put_long(&buffer, &left, bit_a, false);
2861 			if (err)
2862 				break;
2863 			if (bit_a != bit_b) {
2864 				err = proc_put_char(&buffer, &left, '-');
2865 				if (err)
2866 					break;
2867 				err = proc_put_long(&buffer, &left, bit_b, false);
2868 				if (err)
2869 					break;
2870 			}
2871 
2872 			first = 0; bit_b++;
2873 		}
2874 		if (!err)
2875 			err = proc_put_char(&buffer, &left, '\n');
2876 	}
2877 
2878 	if (!err) {
2879 		if (write) {
2880 			if (*ppos)
2881 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2882 			else
2883 				memcpy(bitmap, tmp_bitmap,
2884 					BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2885 		}
2886 		kfree(tmp_bitmap);
2887 		*lenp -= left;
2888 		*ppos += *lenp;
2889 		return 0;
2890 	} else {
2891 		kfree(tmp_bitmap);
2892 		return err;
2893 	}
2894 }
2895 
2896 #else /* CONFIG_PROC_SYSCTL */
2897 
2898 int proc_dostring(struct ctl_table *table, int write,
2899 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2900 {
2901 	return -ENOSYS;
2902 }
2903 
2904 int proc_dointvec(struct ctl_table *table, int write,
2905 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2906 {
2907 	return -ENOSYS;
2908 }
2909 
2910 int proc_dointvec_minmax(struct ctl_table *table, int write,
2911 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2912 {
2913 	return -ENOSYS;
2914 }
2915 
2916 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2917 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2918 {
2919 	return -ENOSYS;
2920 }
2921 
2922 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2923 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2924 {
2925 	return -ENOSYS;
2926 }
2927 
2928 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2929 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2930 {
2931 	return -ENOSYS;
2932 }
2933 
2934 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2935 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2936 {
2937 	return -ENOSYS;
2938 }
2939 
2940 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2941 				      void __user *buffer,
2942 				      size_t *lenp, loff_t *ppos)
2943 {
2944     return -ENOSYS;
2945 }
2946 
2947 
2948 #endif /* CONFIG_PROC_SYSCTL */
2949 
2950 /*
2951  * No sense putting this after each symbol definition, twice,
2952  * exception granted :-)
2953  */
2954 EXPORT_SYMBOL(proc_dointvec);
2955 EXPORT_SYMBOL(proc_dointvec_jiffies);
2956 EXPORT_SYMBOL(proc_dointvec_minmax);
2957 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2958 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2959 EXPORT_SYMBOL(proc_dostring);
2960 EXPORT_SYMBOL(proc_doulongvec_minmax);
2961 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2962 EXPORT_SYMBOL(register_sysctl_table);
2963 EXPORT_SYMBOL(register_sysctl_paths);
2964 EXPORT_SYMBOL(unregister_sysctl_table);
2965