xref: /openbmc/linux/kernel/sysctl.c (revision 79f08d9e)
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/bitmap.h>
27 #include <linux/signal.h>
28 #include <linux/printk.h>
29 #include <linux/proc_fs.h>
30 #include <linux/security.h>
31 #include <linux/ctype.h>
32 #include <linux/kmemcheck.h>
33 #include <linux/kmemleak.h>
34 #include <linux/fs.h>
35 #include <linux/init.h>
36 #include <linux/kernel.h>
37 #include <linux/kobject.h>
38 #include <linux/net.h>
39 #include <linux/sysrq.h>
40 #include <linux/highuid.h>
41 #include <linux/writeback.h>
42 #include <linux/ratelimit.h>
43 #include <linux/compaction.h>
44 #include <linux/hugetlb.h>
45 #include <linux/initrd.h>
46 #include <linux/key.h>
47 #include <linux/times.h>
48 #include <linux/limits.h>
49 #include <linux/dcache.h>
50 #include <linux/dnotify.h>
51 #include <linux/syscalls.h>
52 #include <linux/vmstat.h>
53 #include <linux/nfs_fs.h>
54 #include <linux/acpi.h>
55 #include <linux/reboot.h>
56 #include <linux/ftrace.h>
57 #include <linux/perf_event.h>
58 #include <linux/kprobes.h>
59 #include <linux/pipe_fs_i.h>
60 #include <linux/oom.h>
61 #include <linux/kmod.h>
62 #include <linux/capability.h>
63 #include <linux/binfmts.h>
64 #include <linux/sched/sysctl.h>
65 
66 #include <asm/uaccess.h>
67 #include <asm/processor.h>
68 
69 #ifdef CONFIG_X86
70 #include <asm/nmi.h>
71 #include <asm/stacktrace.h>
72 #include <asm/io.h>
73 #endif
74 #ifdef CONFIG_SPARC
75 #include <asm/setup.h>
76 #endif
77 #ifdef CONFIG_BSD_PROCESS_ACCT
78 #include <linux/acct.h>
79 #endif
80 #ifdef CONFIG_RT_MUTEXES
81 #include <linux/rtmutex.h>
82 #endif
83 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
84 #include <linux/lockdep.h>
85 #endif
86 #ifdef CONFIG_CHR_DEV_SG
87 #include <scsi/sg.h>
88 #endif
89 
90 #ifdef CONFIG_LOCKUP_DETECTOR
91 #include <linux/nmi.h>
92 #endif
93 
94 
95 #if defined(CONFIG_SYSCTL)
96 
97 /* External variables not in a header file. */
98 extern int sysctl_overcommit_memory;
99 extern int sysctl_overcommit_ratio;
100 extern int max_threads;
101 extern int suid_dumpable;
102 #ifdef CONFIG_COREDUMP
103 extern int core_uses_pid;
104 extern char core_pattern[];
105 extern unsigned int core_pipe_limit;
106 #endif
107 extern int pid_max;
108 extern int pid_max_min, pid_max_max;
109 extern int percpu_pagelist_fraction;
110 extern int compat_log;
111 extern int latencytop_enabled;
112 extern int sysctl_nr_open_min, sysctl_nr_open_max;
113 #ifndef CONFIG_MMU
114 extern int sysctl_nr_trim_pages;
115 #endif
116 #ifdef CONFIG_BLOCK
117 extern int blk_iopoll_enabled;
118 #endif
119 
120 /* Constants used for minimum and  maximum */
121 #ifdef CONFIG_LOCKUP_DETECTOR
122 static int sixty = 60;
123 #endif
124 
125 static int zero;
126 static int __maybe_unused one = 1;
127 static int __maybe_unused two = 2;
128 static int __maybe_unused three = 3;
129 static unsigned long one_ul = 1;
130 static int one_hundred = 100;
131 #ifdef CONFIG_PRINTK
132 static int ten_thousand = 10000;
133 #endif
134 
135 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
136 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
137 
138 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
139 static int maxolduid = 65535;
140 static int minolduid;
141 static int min_percpu_pagelist_fract = 8;
142 
143 static int ngroups_max = NGROUPS_MAX;
144 static const int cap_last_cap = CAP_LAST_CAP;
145 
146 #ifdef CONFIG_INOTIFY_USER
147 #include <linux/inotify.h>
148 #endif
149 #ifdef CONFIG_SPARC
150 #endif
151 
152 #ifdef CONFIG_SPARC64
153 extern int sysctl_tsb_ratio;
154 #endif
155 
156 #ifdef __hppa__
157 extern int pwrsw_enabled;
158 #endif
159 
160 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
161 extern int unaligned_enabled;
162 #endif
163 
164 #ifdef CONFIG_IA64
165 extern int unaligned_dump_stack;
166 #endif
167 
168 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
169 extern int no_unaligned_warning;
170 #endif
171 
172 #ifdef CONFIG_PROC_SYSCTL
173 static int proc_do_cad_pid(struct ctl_table *table, int write,
174 		  void __user *buffer, size_t *lenp, loff_t *ppos);
175 static int proc_taint(struct ctl_table *table, int write,
176 			       void __user *buffer, size_t *lenp, loff_t *ppos);
177 #endif
178 
179 #ifdef CONFIG_PRINTK
180 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
181 				void __user *buffer, size_t *lenp, loff_t *ppos);
182 #endif
183 
184 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
185 		void __user *buffer, size_t *lenp, loff_t *ppos);
186 #ifdef CONFIG_COREDUMP
187 static int proc_dostring_coredump(struct ctl_table *table, int write,
188 		void __user *buffer, size_t *lenp, loff_t *ppos);
189 #endif
190 
191 #ifdef CONFIG_MAGIC_SYSRQ
192 /* Note: sysrq code uses it's own private copy */
193 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
194 
195 static int sysrq_sysctl_handler(ctl_table *table, int write,
196 				void __user *buffer, size_t *lenp,
197 				loff_t *ppos)
198 {
199 	int error;
200 
201 	error = proc_dointvec(table, write, buffer, lenp, ppos);
202 	if (error)
203 		return error;
204 
205 	if (write)
206 		sysrq_toggle_support(__sysrq_enabled);
207 
208 	return 0;
209 }
210 
211 #endif
212 
213 static struct ctl_table kern_table[];
214 static struct ctl_table vm_table[];
215 static struct ctl_table fs_table[];
216 static struct ctl_table debug_table[];
217 static struct ctl_table dev_table[];
218 extern struct ctl_table random_table[];
219 #ifdef CONFIG_EPOLL
220 extern struct ctl_table epoll_table[];
221 #endif
222 
223 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
224 int sysctl_legacy_va_layout;
225 #endif
226 
227 /* The default sysctl tables: */
228 
229 static struct ctl_table sysctl_base_table[] = {
230 	{
231 		.procname	= "kernel",
232 		.mode		= 0555,
233 		.child		= kern_table,
234 	},
235 	{
236 		.procname	= "vm",
237 		.mode		= 0555,
238 		.child		= vm_table,
239 	},
240 	{
241 		.procname	= "fs",
242 		.mode		= 0555,
243 		.child		= fs_table,
244 	},
245 	{
246 		.procname	= "debug",
247 		.mode		= 0555,
248 		.child		= debug_table,
249 	},
250 	{
251 		.procname	= "dev",
252 		.mode		= 0555,
253 		.child		= dev_table,
254 	},
255 	{ }
256 };
257 
258 #ifdef CONFIG_SCHED_DEBUG
259 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
260 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
261 static int min_wakeup_granularity_ns;			/* 0 usecs */
262 static int max_wakeup_granularity_ns = NSEC_PER_SEC;	/* 1 second */
263 #ifdef CONFIG_SMP
264 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
265 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
266 #endif /* CONFIG_SMP */
267 #endif /* CONFIG_SCHED_DEBUG */
268 
269 #ifdef CONFIG_COMPACTION
270 static int min_extfrag_threshold;
271 static int max_extfrag_threshold = 1000;
272 #endif
273 
274 static struct ctl_table kern_table[] = {
275 	{
276 		.procname	= "sched_child_runs_first",
277 		.data		= &sysctl_sched_child_runs_first,
278 		.maxlen		= sizeof(unsigned int),
279 		.mode		= 0644,
280 		.proc_handler	= proc_dointvec,
281 	},
282 #ifdef CONFIG_SCHED_DEBUG
283 	{
284 		.procname	= "sched_min_granularity_ns",
285 		.data		= &sysctl_sched_min_granularity,
286 		.maxlen		= sizeof(unsigned int),
287 		.mode		= 0644,
288 		.proc_handler	= sched_proc_update_handler,
289 		.extra1		= &min_sched_granularity_ns,
290 		.extra2		= &max_sched_granularity_ns,
291 	},
292 	{
293 		.procname	= "sched_latency_ns",
294 		.data		= &sysctl_sched_latency,
295 		.maxlen		= sizeof(unsigned int),
296 		.mode		= 0644,
297 		.proc_handler	= sched_proc_update_handler,
298 		.extra1		= &min_sched_granularity_ns,
299 		.extra2		= &max_sched_granularity_ns,
300 	},
301 	{
302 		.procname	= "sched_wakeup_granularity_ns",
303 		.data		= &sysctl_sched_wakeup_granularity,
304 		.maxlen		= sizeof(unsigned int),
305 		.mode		= 0644,
306 		.proc_handler	= sched_proc_update_handler,
307 		.extra1		= &min_wakeup_granularity_ns,
308 		.extra2		= &max_wakeup_granularity_ns,
309 	},
310 #ifdef CONFIG_SMP
311 	{
312 		.procname	= "sched_tunable_scaling",
313 		.data		= &sysctl_sched_tunable_scaling,
314 		.maxlen		= sizeof(enum sched_tunable_scaling),
315 		.mode		= 0644,
316 		.proc_handler	= sched_proc_update_handler,
317 		.extra1		= &min_sched_tunable_scaling,
318 		.extra2		= &max_sched_tunable_scaling,
319 	},
320 	{
321 		.procname	= "sched_migration_cost_ns",
322 		.data		= &sysctl_sched_migration_cost,
323 		.maxlen		= sizeof(unsigned int),
324 		.mode		= 0644,
325 		.proc_handler	= proc_dointvec,
326 	},
327 	{
328 		.procname	= "sched_nr_migrate",
329 		.data		= &sysctl_sched_nr_migrate,
330 		.maxlen		= sizeof(unsigned int),
331 		.mode		= 0644,
332 		.proc_handler	= proc_dointvec,
333 	},
334 	{
335 		.procname	= "sched_time_avg_ms",
336 		.data		= &sysctl_sched_time_avg,
337 		.maxlen		= sizeof(unsigned int),
338 		.mode		= 0644,
339 		.proc_handler	= proc_dointvec,
340 	},
341 	{
342 		.procname	= "sched_shares_window_ns",
343 		.data		= &sysctl_sched_shares_window,
344 		.maxlen		= sizeof(unsigned int),
345 		.mode		= 0644,
346 		.proc_handler	= proc_dointvec,
347 	},
348 	{
349 		.procname	= "timer_migration",
350 		.data		= &sysctl_timer_migration,
351 		.maxlen		= sizeof(unsigned int),
352 		.mode		= 0644,
353 		.proc_handler	= proc_dointvec_minmax,
354 		.extra1		= &zero,
355 		.extra2		= &one,
356 	},
357 #endif /* CONFIG_SMP */
358 #ifdef CONFIG_NUMA_BALANCING
359 	{
360 		.procname	= "numa_balancing_scan_delay_ms",
361 		.data		= &sysctl_numa_balancing_scan_delay,
362 		.maxlen		= sizeof(unsigned int),
363 		.mode		= 0644,
364 		.proc_handler	= proc_dointvec,
365 	},
366 	{
367 		.procname	= "numa_balancing_scan_period_min_ms",
368 		.data		= &sysctl_numa_balancing_scan_period_min,
369 		.maxlen		= sizeof(unsigned int),
370 		.mode		= 0644,
371 		.proc_handler	= proc_dointvec,
372 	},
373 	{
374 		.procname	= "numa_balancing_scan_period_max_ms",
375 		.data		= &sysctl_numa_balancing_scan_period_max,
376 		.maxlen		= sizeof(unsigned int),
377 		.mode		= 0644,
378 		.proc_handler	= proc_dointvec,
379 	},
380 	{
381 		.procname	= "numa_balancing_scan_size_mb",
382 		.data		= &sysctl_numa_balancing_scan_size,
383 		.maxlen		= sizeof(unsigned int),
384 		.mode		= 0644,
385 		.proc_handler	= proc_dointvec,
386 	},
387 	{
388 		.procname       = "numa_balancing_settle_count",
389 		.data           = &sysctl_numa_balancing_settle_count,
390 		.maxlen         = sizeof(unsigned int),
391 		.mode           = 0644,
392 		.proc_handler   = proc_dointvec,
393 	},
394 	{
395 		.procname       = "numa_balancing_migrate_deferred",
396 		.data           = &sysctl_numa_balancing_migrate_deferred,
397 		.maxlen         = sizeof(unsigned int),
398 		.mode           = 0644,
399 		.proc_handler   = proc_dointvec,
400 	},
401 #endif /* CONFIG_NUMA_BALANCING */
402 #endif /* CONFIG_SCHED_DEBUG */
403 	{
404 		.procname	= "sched_rt_period_us",
405 		.data		= &sysctl_sched_rt_period,
406 		.maxlen		= sizeof(unsigned int),
407 		.mode		= 0644,
408 		.proc_handler	= sched_rt_handler,
409 	},
410 	{
411 		.procname	= "sched_rt_runtime_us",
412 		.data		= &sysctl_sched_rt_runtime,
413 		.maxlen		= sizeof(int),
414 		.mode		= 0644,
415 		.proc_handler	= sched_rt_handler,
416 	},
417 	{
418 		.procname	= "sched_rr_timeslice_ms",
419 		.data		= &sched_rr_timeslice,
420 		.maxlen		= sizeof(int),
421 		.mode		= 0644,
422 		.proc_handler	= sched_rr_handler,
423 	},
424 #ifdef CONFIG_SCHED_AUTOGROUP
425 	{
426 		.procname	= "sched_autogroup_enabled",
427 		.data		= &sysctl_sched_autogroup_enabled,
428 		.maxlen		= sizeof(unsigned int),
429 		.mode		= 0644,
430 		.proc_handler	= proc_dointvec_minmax,
431 		.extra1		= &zero,
432 		.extra2		= &one,
433 	},
434 #endif
435 #ifdef CONFIG_CFS_BANDWIDTH
436 	{
437 		.procname	= "sched_cfs_bandwidth_slice_us",
438 		.data		= &sysctl_sched_cfs_bandwidth_slice,
439 		.maxlen		= sizeof(unsigned int),
440 		.mode		= 0644,
441 		.proc_handler	= proc_dointvec_minmax,
442 		.extra1		= &one,
443 	},
444 #endif
445 #ifdef CONFIG_PROVE_LOCKING
446 	{
447 		.procname	= "prove_locking",
448 		.data		= &prove_locking,
449 		.maxlen		= sizeof(int),
450 		.mode		= 0644,
451 		.proc_handler	= proc_dointvec,
452 	},
453 #endif
454 #ifdef CONFIG_LOCK_STAT
455 	{
456 		.procname	= "lock_stat",
457 		.data		= &lock_stat,
458 		.maxlen		= sizeof(int),
459 		.mode		= 0644,
460 		.proc_handler	= proc_dointvec,
461 	},
462 #endif
463 	{
464 		.procname	= "panic",
465 		.data		= &panic_timeout,
466 		.maxlen		= sizeof(int),
467 		.mode		= 0644,
468 		.proc_handler	= proc_dointvec,
469 	},
470 #ifdef CONFIG_COREDUMP
471 	{
472 		.procname	= "core_uses_pid",
473 		.data		= &core_uses_pid,
474 		.maxlen		= sizeof(int),
475 		.mode		= 0644,
476 		.proc_handler	= proc_dointvec,
477 	},
478 	{
479 		.procname	= "core_pattern",
480 		.data		= core_pattern,
481 		.maxlen		= CORENAME_MAX_SIZE,
482 		.mode		= 0644,
483 		.proc_handler	= proc_dostring_coredump,
484 	},
485 	{
486 		.procname	= "core_pipe_limit",
487 		.data		= &core_pipe_limit,
488 		.maxlen		= sizeof(unsigned int),
489 		.mode		= 0644,
490 		.proc_handler	= proc_dointvec,
491 	},
492 #endif
493 #ifdef CONFIG_PROC_SYSCTL
494 	{
495 		.procname	= "tainted",
496 		.maxlen 	= sizeof(long),
497 		.mode		= 0644,
498 		.proc_handler	= proc_taint,
499 	},
500 #endif
501 #ifdef CONFIG_LATENCYTOP
502 	{
503 		.procname	= "latencytop",
504 		.data		= &latencytop_enabled,
505 		.maxlen		= sizeof(int),
506 		.mode		= 0644,
507 		.proc_handler	= proc_dointvec,
508 	},
509 #endif
510 #ifdef CONFIG_BLK_DEV_INITRD
511 	{
512 		.procname	= "real-root-dev",
513 		.data		= &real_root_dev,
514 		.maxlen		= sizeof(int),
515 		.mode		= 0644,
516 		.proc_handler	= proc_dointvec,
517 	},
518 #endif
519 	{
520 		.procname	= "print-fatal-signals",
521 		.data		= &print_fatal_signals,
522 		.maxlen		= sizeof(int),
523 		.mode		= 0644,
524 		.proc_handler	= proc_dointvec,
525 	},
526 #ifdef CONFIG_SPARC
527 	{
528 		.procname	= "reboot-cmd",
529 		.data		= reboot_command,
530 		.maxlen		= 256,
531 		.mode		= 0644,
532 		.proc_handler	= proc_dostring,
533 	},
534 	{
535 		.procname	= "stop-a",
536 		.data		= &stop_a_enabled,
537 		.maxlen		= sizeof (int),
538 		.mode		= 0644,
539 		.proc_handler	= proc_dointvec,
540 	},
541 	{
542 		.procname	= "scons-poweroff",
543 		.data		= &scons_pwroff,
544 		.maxlen		= sizeof (int),
545 		.mode		= 0644,
546 		.proc_handler	= proc_dointvec,
547 	},
548 #endif
549 #ifdef CONFIG_SPARC64
550 	{
551 		.procname	= "tsb-ratio",
552 		.data		= &sysctl_tsb_ratio,
553 		.maxlen		= sizeof (int),
554 		.mode		= 0644,
555 		.proc_handler	= proc_dointvec,
556 	},
557 #endif
558 #ifdef __hppa__
559 	{
560 		.procname	= "soft-power",
561 		.data		= &pwrsw_enabled,
562 		.maxlen		= sizeof (int),
563 	 	.mode		= 0644,
564 		.proc_handler	= proc_dointvec,
565 	},
566 #endif
567 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
568 	{
569 		.procname	= "unaligned-trap",
570 		.data		= &unaligned_enabled,
571 		.maxlen		= sizeof (int),
572 		.mode		= 0644,
573 		.proc_handler	= proc_dointvec,
574 	},
575 #endif
576 	{
577 		.procname	= "ctrl-alt-del",
578 		.data		= &C_A_D,
579 		.maxlen		= sizeof(int),
580 		.mode		= 0644,
581 		.proc_handler	= proc_dointvec,
582 	},
583 #ifdef CONFIG_FUNCTION_TRACER
584 	{
585 		.procname	= "ftrace_enabled",
586 		.data		= &ftrace_enabled,
587 		.maxlen		= sizeof(int),
588 		.mode		= 0644,
589 		.proc_handler	= ftrace_enable_sysctl,
590 	},
591 #endif
592 #ifdef CONFIG_STACK_TRACER
593 	{
594 		.procname	= "stack_tracer_enabled",
595 		.data		= &stack_tracer_enabled,
596 		.maxlen		= sizeof(int),
597 		.mode		= 0644,
598 		.proc_handler	= stack_trace_sysctl,
599 	},
600 #endif
601 #ifdef CONFIG_TRACING
602 	{
603 		.procname	= "ftrace_dump_on_oops",
604 		.data		= &ftrace_dump_on_oops,
605 		.maxlen		= sizeof(int),
606 		.mode		= 0644,
607 		.proc_handler	= proc_dointvec,
608 	},
609 	{
610 		.procname	= "traceoff_on_warning",
611 		.data		= &__disable_trace_on_warning,
612 		.maxlen		= sizeof(__disable_trace_on_warning),
613 		.mode		= 0644,
614 		.proc_handler	= proc_dointvec,
615 	},
616 #endif
617 #ifdef CONFIG_MODULES
618 	{
619 		.procname	= "modprobe",
620 		.data		= &modprobe_path,
621 		.maxlen		= KMOD_PATH_LEN,
622 		.mode		= 0644,
623 		.proc_handler	= proc_dostring,
624 	},
625 	{
626 		.procname	= "modules_disabled",
627 		.data		= &modules_disabled,
628 		.maxlen		= sizeof(int),
629 		.mode		= 0644,
630 		/* only handle a transition from default "0" to "1" */
631 		.proc_handler	= proc_dointvec_minmax,
632 		.extra1		= &one,
633 		.extra2		= &one,
634 	},
635 #endif
636 
637 	{
638 		.procname	= "hotplug",
639 		.data		= &uevent_helper,
640 		.maxlen		= UEVENT_HELPER_PATH_LEN,
641 		.mode		= 0644,
642 		.proc_handler	= proc_dostring,
643 	},
644 
645 #ifdef CONFIG_CHR_DEV_SG
646 	{
647 		.procname	= "sg-big-buff",
648 		.data		= &sg_big_buff,
649 		.maxlen		= sizeof (int),
650 		.mode		= 0444,
651 		.proc_handler	= proc_dointvec,
652 	},
653 #endif
654 #ifdef CONFIG_BSD_PROCESS_ACCT
655 	{
656 		.procname	= "acct",
657 		.data		= &acct_parm,
658 		.maxlen		= 3*sizeof(int),
659 		.mode		= 0644,
660 		.proc_handler	= proc_dointvec,
661 	},
662 #endif
663 #ifdef CONFIG_MAGIC_SYSRQ
664 	{
665 		.procname	= "sysrq",
666 		.data		= &__sysrq_enabled,
667 		.maxlen		= sizeof (int),
668 		.mode		= 0644,
669 		.proc_handler	= sysrq_sysctl_handler,
670 	},
671 #endif
672 #ifdef CONFIG_PROC_SYSCTL
673 	{
674 		.procname	= "cad_pid",
675 		.data		= NULL,
676 		.maxlen		= sizeof (int),
677 		.mode		= 0600,
678 		.proc_handler	= proc_do_cad_pid,
679 	},
680 #endif
681 	{
682 		.procname	= "threads-max",
683 		.data		= &max_threads,
684 		.maxlen		= sizeof(int),
685 		.mode		= 0644,
686 		.proc_handler	= proc_dointvec,
687 	},
688 	{
689 		.procname	= "random",
690 		.mode		= 0555,
691 		.child		= random_table,
692 	},
693 	{
694 		.procname	= "usermodehelper",
695 		.mode		= 0555,
696 		.child		= usermodehelper_table,
697 	},
698 	{
699 		.procname	= "overflowuid",
700 		.data		= &overflowuid,
701 		.maxlen		= sizeof(int),
702 		.mode		= 0644,
703 		.proc_handler	= proc_dointvec_minmax,
704 		.extra1		= &minolduid,
705 		.extra2		= &maxolduid,
706 	},
707 	{
708 		.procname	= "overflowgid",
709 		.data		= &overflowgid,
710 		.maxlen		= sizeof(int),
711 		.mode		= 0644,
712 		.proc_handler	= proc_dointvec_minmax,
713 		.extra1		= &minolduid,
714 		.extra2		= &maxolduid,
715 	},
716 #ifdef CONFIG_S390
717 #ifdef CONFIG_MATHEMU
718 	{
719 		.procname	= "ieee_emulation_warnings",
720 		.data		= &sysctl_ieee_emulation_warnings,
721 		.maxlen		= sizeof(int),
722 		.mode		= 0644,
723 		.proc_handler	= proc_dointvec,
724 	},
725 #endif
726 	{
727 		.procname	= "userprocess_debug",
728 		.data		= &show_unhandled_signals,
729 		.maxlen		= sizeof(int),
730 		.mode		= 0644,
731 		.proc_handler	= proc_dointvec,
732 	},
733 #endif
734 	{
735 		.procname	= "pid_max",
736 		.data		= &pid_max,
737 		.maxlen		= sizeof (int),
738 		.mode		= 0644,
739 		.proc_handler	= proc_dointvec_minmax,
740 		.extra1		= &pid_max_min,
741 		.extra2		= &pid_max_max,
742 	},
743 	{
744 		.procname	= "panic_on_oops",
745 		.data		= &panic_on_oops,
746 		.maxlen		= sizeof(int),
747 		.mode		= 0644,
748 		.proc_handler	= proc_dointvec,
749 	},
750 #if defined CONFIG_PRINTK
751 	{
752 		.procname	= "printk",
753 		.data		= &console_loglevel,
754 		.maxlen		= 4*sizeof(int),
755 		.mode		= 0644,
756 		.proc_handler	= proc_dointvec,
757 	},
758 	{
759 		.procname	= "printk_ratelimit",
760 		.data		= &printk_ratelimit_state.interval,
761 		.maxlen		= sizeof(int),
762 		.mode		= 0644,
763 		.proc_handler	= proc_dointvec_jiffies,
764 	},
765 	{
766 		.procname	= "printk_ratelimit_burst",
767 		.data		= &printk_ratelimit_state.burst,
768 		.maxlen		= sizeof(int),
769 		.mode		= 0644,
770 		.proc_handler	= proc_dointvec,
771 	},
772 	{
773 		.procname	= "printk_delay",
774 		.data		= &printk_delay_msec,
775 		.maxlen		= sizeof(int),
776 		.mode		= 0644,
777 		.proc_handler	= proc_dointvec_minmax,
778 		.extra1		= &zero,
779 		.extra2		= &ten_thousand,
780 	},
781 	{
782 		.procname	= "dmesg_restrict",
783 		.data		= &dmesg_restrict,
784 		.maxlen		= sizeof(int),
785 		.mode		= 0644,
786 		.proc_handler	= proc_dointvec_minmax_sysadmin,
787 		.extra1		= &zero,
788 		.extra2		= &one,
789 	},
790 	{
791 		.procname	= "kptr_restrict",
792 		.data		= &kptr_restrict,
793 		.maxlen		= sizeof(int),
794 		.mode		= 0644,
795 		.proc_handler	= proc_dointvec_minmax_sysadmin,
796 		.extra1		= &zero,
797 		.extra2		= &two,
798 	},
799 #endif
800 	{
801 		.procname	= "ngroups_max",
802 		.data		= &ngroups_max,
803 		.maxlen		= sizeof (int),
804 		.mode		= 0444,
805 		.proc_handler	= proc_dointvec,
806 	},
807 	{
808 		.procname	= "cap_last_cap",
809 		.data		= (void *)&cap_last_cap,
810 		.maxlen		= sizeof(int),
811 		.mode		= 0444,
812 		.proc_handler	= proc_dointvec,
813 	},
814 #if defined(CONFIG_LOCKUP_DETECTOR)
815 	{
816 		.procname       = "watchdog",
817 		.data           = &watchdog_user_enabled,
818 		.maxlen         = sizeof (int),
819 		.mode           = 0644,
820 		.proc_handler   = proc_dowatchdog,
821 		.extra1		= &zero,
822 		.extra2		= &one,
823 	},
824 	{
825 		.procname	= "watchdog_thresh",
826 		.data		= &watchdog_thresh,
827 		.maxlen		= sizeof(int),
828 		.mode		= 0644,
829 		.proc_handler	= proc_dowatchdog,
830 		.extra1		= &zero,
831 		.extra2		= &sixty,
832 	},
833 	{
834 		.procname	= "softlockup_panic",
835 		.data		= &softlockup_panic,
836 		.maxlen		= sizeof(int),
837 		.mode		= 0644,
838 		.proc_handler	= proc_dointvec_minmax,
839 		.extra1		= &zero,
840 		.extra2		= &one,
841 	},
842 	{
843 		.procname       = "nmi_watchdog",
844 		.data           = &watchdog_user_enabled,
845 		.maxlen         = sizeof (int),
846 		.mode           = 0644,
847 		.proc_handler   = proc_dowatchdog,
848 		.extra1		= &zero,
849 		.extra2		= &one,
850 	},
851 #endif
852 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
853 	{
854 		.procname       = "unknown_nmi_panic",
855 		.data           = &unknown_nmi_panic,
856 		.maxlen         = sizeof (int),
857 		.mode           = 0644,
858 		.proc_handler   = proc_dointvec,
859 	},
860 #endif
861 #if defined(CONFIG_X86)
862 	{
863 		.procname	= "panic_on_unrecovered_nmi",
864 		.data		= &panic_on_unrecovered_nmi,
865 		.maxlen		= sizeof(int),
866 		.mode		= 0644,
867 		.proc_handler	= proc_dointvec,
868 	},
869 	{
870 		.procname	= "panic_on_io_nmi",
871 		.data		= &panic_on_io_nmi,
872 		.maxlen		= sizeof(int),
873 		.mode		= 0644,
874 		.proc_handler	= proc_dointvec,
875 	},
876 #ifdef CONFIG_DEBUG_STACKOVERFLOW
877 	{
878 		.procname	= "panic_on_stackoverflow",
879 		.data		= &sysctl_panic_on_stackoverflow,
880 		.maxlen		= sizeof(int),
881 		.mode		= 0644,
882 		.proc_handler	= proc_dointvec,
883 	},
884 #endif
885 	{
886 		.procname	= "bootloader_type",
887 		.data		= &bootloader_type,
888 		.maxlen		= sizeof (int),
889 		.mode		= 0444,
890 		.proc_handler	= proc_dointvec,
891 	},
892 	{
893 		.procname	= "bootloader_version",
894 		.data		= &bootloader_version,
895 		.maxlen		= sizeof (int),
896 		.mode		= 0444,
897 		.proc_handler	= proc_dointvec,
898 	},
899 	{
900 		.procname	= "kstack_depth_to_print",
901 		.data		= &kstack_depth_to_print,
902 		.maxlen		= sizeof(int),
903 		.mode		= 0644,
904 		.proc_handler	= proc_dointvec,
905 	},
906 	{
907 		.procname	= "io_delay_type",
908 		.data		= &io_delay_type,
909 		.maxlen		= sizeof(int),
910 		.mode		= 0644,
911 		.proc_handler	= proc_dointvec,
912 	},
913 #endif
914 #if defined(CONFIG_MMU)
915 	{
916 		.procname	= "randomize_va_space",
917 		.data		= &randomize_va_space,
918 		.maxlen		= sizeof(int),
919 		.mode		= 0644,
920 		.proc_handler	= proc_dointvec,
921 	},
922 #endif
923 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
924 	{
925 		.procname	= "spin_retry",
926 		.data		= &spin_retry,
927 		.maxlen		= sizeof (int),
928 		.mode		= 0644,
929 		.proc_handler	= proc_dointvec,
930 	},
931 #endif
932 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
933 	{
934 		.procname	= "acpi_video_flags",
935 		.data		= &acpi_realmode_flags,
936 		.maxlen		= sizeof (unsigned long),
937 		.mode		= 0644,
938 		.proc_handler	= proc_doulongvec_minmax,
939 	},
940 #endif
941 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
942 	{
943 		.procname	= "ignore-unaligned-usertrap",
944 		.data		= &no_unaligned_warning,
945 		.maxlen		= sizeof (int),
946 	 	.mode		= 0644,
947 		.proc_handler	= proc_dointvec,
948 	},
949 #endif
950 #ifdef CONFIG_IA64
951 	{
952 		.procname	= "unaligned-dump-stack",
953 		.data		= &unaligned_dump_stack,
954 		.maxlen		= sizeof (int),
955 		.mode		= 0644,
956 		.proc_handler	= proc_dointvec,
957 	},
958 #endif
959 #ifdef CONFIG_DETECT_HUNG_TASK
960 	{
961 		.procname	= "hung_task_panic",
962 		.data		= &sysctl_hung_task_panic,
963 		.maxlen		= sizeof(int),
964 		.mode		= 0644,
965 		.proc_handler	= proc_dointvec_minmax,
966 		.extra1		= &zero,
967 		.extra2		= &one,
968 	},
969 	{
970 		.procname	= "hung_task_check_count",
971 		.data		= &sysctl_hung_task_check_count,
972 		.maxlen		= sizeof(int),
973 		.mode		= 0644,
974 		.proc_handler	= proc_dointvec_minmax,
975 		.extra1		= &zero,
976 	},
977 	{
978 		.procname	= "hung_task_timeout_secs",
979 		.data		= &sysctl_hung_task_timeout_secs,
980 		.maxlen		= sizeof(unsigned long),
981 		.mode		= 0644,
982 		.proc_handler	= proc_dohung_task_timeout_secs,
983 	},
984 	{
985 		.procname	= "hung_task_warnings",
986 		.data		= &sysctl_hung_task_warnings,
987 		.maxlen		= sizeof(unsigned long),
988 		.mode		= 0644,
989 		.proc_handler	= proc_doulongvec_minmax,
990 	},
991 #endif
992 #ifdef CONFIG_COMPAT
993 	{
994 		.procname	= "compat-log",
995 		.data		= &compat_log,
996 		.maxlen		= sizeof (int),
997 	 	.mode		= 0644,
998 		.proc_handler	= proc_dointvec,
999 	},
1000 #endif
1001 #ifdef CONFIG_RT_MUTEXES
1002 	{
1003 		.procname	= "max_lock_depth",
1004 		.data		= &max_lock_depth,
1005 		.maxlen		= sizeof(int),
1006 		.mode		= 0644,
1007 		.proc_handler	= proc_dointvec,
1008 	},
1009 #endif
1010 	{
1011 		.procname	= "poweroff_cmd",
1012 		.data		= &poweroff_cmd,
1013 		.maxlen		= POWEROFF_CMD_PATH_LEN,
1014 		.mode		= 0644,
1015 		.proc_handler	= proc_dostring,
1016 	},
1017 #ifdef CONFIG_KEYS
1018 	{
1019 		.procname	= "keys",
1020 		.mode		= 0555,
1021 		.child		= key_sysctls,
1022 	},
1023 #endif
1024 #ifdef CONFIG_RCU_TORTURE_TEST
1025 	{
1026 		.procname       = "rcutorture_runnable",
1027 		.data           = &rcutorture_runnable,
1028 		.maxlen         = sizeof(int),
1029 		.mode           = 0644,
1030 		.proc_handler	= proc_dointvec,
1031 	},
1032 #endif
1033 #ifdef CONFIG_PERF_EVENTS
1034 	/*
1035 	 * User-space scripts rely on the existence of this file
1036 	 * as a feature check for perf_events being enabled.
1037 	 *
1038 	 * So it's an ABI, do not remove!
1039 	 */
1040 	{
1041 		.procname	= "perf_event_paranoid",
1042 		.data		= &sysctl_perf_event_paranoid,
1043 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
1044 		.mode		= 0644,
1045 		.proc_handler	= proc_dointvec,
1046 	},
1047 	{
1048 		.procname	= "perf_event_mlock_kb",
1049 		.data		= &sysctl_perf_event_mlock,
1050 		.maxlen		= sizeof(sysctl_perf_event_mlock),
1051 		.mode		= 0644,
1052 		.proc_handler	= proc_dointvec,
1053 	},
1054 	{
1055 		.procname	= "perf_event_max_sample_rate",
1056 		.data		= &sysctl_perf_event_sample_rate,
1057 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
1058 		.mode		= 0644,
1059 		.proc_handler	= perf_proc_update_handler,
1060 		.extra1		= &one,
1061 	},
1062 	{
1063 		.procname	= "perf_cpu_time_max_percent",
1064 		.data		= &sysctl_perf_cpu_time_max_percent,
1065 		.maxlen		= sizeof(sysctl_perf_cpu_time_max_percent),
1066 		.mode		= 0644,
1067 		.proc_handler	= perf_cpu_time_max_percent_handler,
1068 		.extra1		= &zero,
1069 		.extra2		= &one_hundred,
1070 	},
1071 #endif
1072 #ifdef CONFIG_KMEMCHECK
1073 	{
1074 		.procname	= "kmemcheck",
1075 		.data		= &kmemcheck_enabled,
1076 		.maxlen		= sizeof(int),
1077 		.mode		= 0644,
1078 		.proc_handler	= proc_dointvec,
1079 	},
1080 #endif
1081 #ifdef CONFIG_BLOCK
1082 	{
1083 		.procname	= "blk_iopoll",
1084 		.data		= &blk_iopoll_enabled,
1085 		.maxlen		= sizeof(int),
1086 		.mode		= 0644,
1087 		.proc_handler	= proc_dointvec,
1088 	},
1089 #endif
1090 	{ }
1091 };
1092 
1093 static struct ctl_table vm_table[] = {
1094 	{
1095 		.procname	= "overcommit_memory",
1096 		.data		= &sysctl_overcommit_memory,
1097 		.maxlen		= sizeof(sysctl_overcommit_memory),
1098 		.mode		= 0644,
1099 		.proc_handler	= proc_dointvec_minmax,
1100 		.extra1		= &zero,
1101 		.extra2		= &two,
1102 	},
1103 	{
1104 		.procname	= "panic_on_oom",
1105 		.data		= &sysctl_panic_on_oom,
1106 		.maxlen		= sizeof(sysctl_panic_on_oom),
1107 		.mode		= 0644,
1108 		.proc_handler	= proc_dointvec_minmax,
1109 		.extra1		= &zero,
1110 		.extra2		= &two,
1111 	},
1112 	{
1113 		.procname	= "oom_kill_allocating_task",
1114 		.data		= &sysctl_oom_kill_allocating_task,
1115 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1116 		.mode		= 0644,
1117 		.proc_handler	= proc_dointvec,
1118 	},
1119 	{
1120 		.procname	= "oom_dump_tasks",
1121 		.data		= &sysctl_oom_dump_tasks,
1122 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1123 		.mode		= 0644,
1124 		.proc_handler	= proc_dointvec,
1125 	},
1126 	{
1127 		.procname	= "overcommit_ratio",
1128 		.data		= &sysctl_overcommit_ratio,
1129 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1130 		.mode		= 0644,
1131 		.proc_handler	= proc_dointvec,
1132 	},
1133 	{
1134 		.procname	= "page-cluster",
1135 		.data		= &page_cluster,
1136 		.maxlen		= sizeof(int),
1137 		.mode		= 0644,
1138 		.proc_handler	= proc_dointvec_minmax,
1139 		.extra1		= &zero,
1140 	},
1141 	{
1142 		.procname	= "dirty_background_ratio",
1143 		.data		= &dirty_background_ratio,
1144 		.maxlen		= sizeof(dirty_background_ratio),
1145 		.mode		= 0644,
1146 		.proc_handler	= dirty_background_ratio_handler,
1147 		.extra1		= &zero,
1148 		.extra2		= &one_hundred,
1149 	},
1150 	{
1151 		.procname	= "dirty_background_bytes",
1152 		.data		= &dirty_background_bytes,
1153 		.maxlen		= sizeof(dirty_background_bytes),
1154 		.mode		= 0644,
1155 		.proc_handler	= dirty_background_bytes_handler,
1156 		.extra1		= &one_ul,
1157 	},
1158 	{
1159 		.procname	= "dirty_ratio",
1160 		.data		= &vm_dirty_ratio,
1161 		.maxlen		= sizeof(vm_dirty_ratio),
1162 		.mode		= 0644,
1163 		.proc_handler	= dirty_ratio_handler,
1164 		.extra1		= &zero,
1165 		.extra2		= &one_hundred,
1166 	},
1167 	{
1168 		.procname	= "dirty_bytes",
1169 		.data		= &vm_dirty_bytes,
1170 		.maxlen		= sizeof(vm_dirty_bytes),
1171 		.mode		= 0644,
1172 		.proc_handler	= dirty_bytes_handler,
1173 		.extra1		= &dirty_bytes_min,
1174 	},
1175 	{
1176 		.procname	= "dirty_writeback_centisecs",
1177 		.data		= &dirty_writeback_interval,
1178 		.maxlen		= sizeof(dirty_writeback_interval),
1179 		.mode		= 0644,
1180 		.proc_handler	= dirty_writeback_centisecs_handler,
1181 	},
1182 	{
1183 		.procname	= "dirty_expire_centisecs",
1184 		.data		= &dirty_expire_interval,
1185 		.maxlen		= sizeof(dirty_expire_interval),
1186 		.mode		= 0644,
1187 		.proc_handler	= proc_dointvec_minmax,
1188 		.extra1		= &zero,
1189 	},
1190 	{
1191 		.procname       = "nr_pdflush_threads",
1192 		.mode           = 0444 /* read-only */,
1193 		.proc_handler   = pdflush_proc_obsolete,
1194 	},
1195 	{
1196 		.procname	= "swappiness",
1197 		.data		= &vm_swappiness,
1198 		.maxlen		= sizeof(vm_swappiness),
1199 		.mode		= 0644,
1200 		.proc_handler	= proc_dointvec_minmax,
1201 		.extra1		= &zero,
1202 		.extra2		= &one_hundred,
1203 	},
1204 #ifdef CONFIG_HUGETLB_PAGE
1205 	{
1206 		.procname	= "nr_hugepages",
1207 		.data		= NULL,
1208 		.maxlen		= sizeof(unsigned long),
1209 		.mode		= 0644,
1210 		.proc_handler	= hugetlb_sysctl_handler,
1211 		.extra1		= (void *)&hugetlb_zero,
1212 		.extra2		= (void *)&hugetlb_infinity,
1213 	},
1214 #ifdef CONFIG_NUMA
1215 	{
1216 		.procname       = "nr_hugepages_mempolicy",
1217 		.data           = NULL,
1218 		.maxlen         = sizeof(unsigned long),
1219 		.mode           = 0644,
1220 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1221 		.extra1		= (void *)&hugetlb_zero,
1222 		.extra2		= (void *)&hugetlb_infinity,
1223 	},
1224 #endif
1225 	 {
1226 		.procname	= "hugetlb_shm_group",
1227 		.data		= &sysctl_hugetlb_shm_group,
1228 		.maxlen		= sizeof(gid_t),
1229 		.mode		= 0644,
1230 		.proc_handler	= proc_dointvec,
1231 	 },
1232 	 {
1233 		.procname	= "hugepages_treat_as_movable",
1234 		.data		= &hugepages_treat_as_movable,
1235 		.maxlen		= sizeof(int),
1236 		.mode		= 0644,
1237 		.proc_handler	= proc_dointvec,
1238 	},
1239 	{
1240 		.procname	= "nr_overcommit_hugepages",
1241 		.data		= NULL,
1242 		.maxlen		= sizeof(unsigned long),
1243 		.mode		= 0644,
1244 		.proc_handler	= hugetlb_overcommit_handler,
1245 		.extra1		= (void *)&hugetlb_zero,
1246 		.extra2		= (void *)&hugetlb_infinity,
1247 	},
1248 #endif
1249 	{
1250 		.procname	= "lowmem_reserve_ratio",
1251 		.data		= &sysctl_lowmem_reserve_ratio,
1252 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1253 		.mode		= 0644,
1254 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1255 	},
1256 	{
1257 		.procname	= "drop_caches",
1258 		.data		= &sysctl_drop_caches,
1259 		.maxlen		= sizeof(int),
1260 		.mode		= 0644,
1261 		.proc_handler	= drop_caches_sysctl_handler,
1262 		.extra1		= &one,
1263 		.extra2		= &three,
1264 	},
1265 #ifdef CONFIG_COMPACTION
1266 	{
1267 		.procname	= "compact_memory",
1268 		.data		= &sysctl_compact_memory,
1269 		.maxlen		= sizeof(int),
1270 		.mode		= 0200,
1271 		.proc_handler	= sysctl_compaction_handler,
1272 	},
1273 	{
1274 		.procname	= "extfrag_threshold",
1275 		.data		= &sysctl_extfrag_threshold,
1276 		.maxlen		= sizeof(int),
1277 		.mode		= 0644,
1278 		.proc_handler	= sysctl_extfrag_handler,
1279 		.extra1		= &min_extfrag_threshold,
1280 		.extra2		= &max_extfrag_threshold,
1281 	},
1282 
1283 #endif /* CONFIG_COMPACTION */
1284 	{
1285 		.procname	= "min_free_kbytes",
1286 		.data		= &min_free_kbytes,
1287 		.maxlen		= sizeof(min_free_kbytes),
1288 		.mode		= 0644,
1289 		.proc_handler	= min_free_kbytes_sysctl_handler,
1290 		.extra1		= &zero,
1291 	},
1292 	{
1293 		.procname	= "percpu_pagelist_fraction",
1294 		.data		= &percpu_pagelist_fraction,
1295 		.maxlen		= sizeof(percpu_pagelist_fraction),
1296 		.mode		= 0644,
1297 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1298 		.extra1		= &min_percpu_pagelist_fract,
1299 	},
1300 #ifdef CONFIG_MMU
1301 	{
1302 		.procname	= "max_map_count",
1303 		.data		= &sysctl_max_map_count,
1304 		.maxlen		= sizeof(sysctl_max_map_count),
1305 		.mode		= 0644,
1306 		.proc_handler	= proc_dointvec_minmax,
1307 		.extra1		= &zero,
1308 	},
1309 #else
1310 	{
1311 		.procname	= "nr_trim_pages",
1312 		.data		= &sysctl_nr_trim_pages,
1313 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1314 		.mode		= 0644,
1315 		.proc_handler	= proc_dointvec_minmax,
1316 		.extra1		= &zero,
1317 	},
1318 #endif
1319 	{
1320 		.procname	= "laptop_mode",
1321 		.data		= &laptop_mode,
1322 		.maxlen		= sizeof(laptop_mode),
1323 		.mode		= 0644,
1324 		.proc_handler	= proc_dointvec_jiffies,
1325 	},
1326 	{
1327 		.procname	= "block_dump",
1328 		.data		= &block_dump,
1329 		.maxlen		= sizeof(block_dump),
1330 		.mode		= 0644,
1331 		.proc_handler	= proc_dointvec,
1332 		.extra1		= &zero,
1333 	},
1334 	{
1335 		.procname	= "vfs_cache_pressure",
1336 		.data		= &sysctl_vfs_cache_pressure,
1337 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1338 		.mode		= 0644,
1339 		.proc_handler	= proc_dointvec,
1340 		.extra1		= &zero,
1341 	},
1342 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1343 	{
1344 		.procname	= "legacy_va_layout",
1345 		.data		= &sysctl_legacy_va_layout,
1346 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1347 		.mode		= 0644,
1348 		.proc_handler	= proc_dointvec,
1349 		.extra1		= &zero,
1350 	},
1351 #endif
1352 #ifdef CONFIG_NUMA
1353 	{
1354 		.procname	= "zone_reclaim_mode",
1355 		.data		= &zone_reclaim_mode,
1356 		.maxlen		= sizeof(zone_reclaim_mode),
1357 		.mode		= 0644,
1358 		.proc_handler	= proc_dointvec,
1359 		.extra1		= &zero,
1360 	},
1361 	{
1362 		.procname	= "min_unmapped_ratio",
1363 		.data		= &sysctl_min_unmapped_ratio,
1364 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1365 		.mode		= 0644,
1366 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1367 		.extra1		= &zero,
1368 		.extra2		= &one_hundred,
1369 	},
1370 	{
1371 		.procname	= "min_slab_ratio",
1372 		.data		= &sysctl_min_slab_ratio,
1373 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1374 		.mode		= 0644,
1375 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1376 		.extra1		= &zero,
1377 		.extra2		= &one_hundred,
1378 	},
1379 #endif
1380 #ifdef CONFIG_SMP
1381 	{
1382 		.procname	= "stat_interval",
1383 		.data		= &sysctl_stat_interval,
1384 		.maxlen		= sizeof(sysctl_stat_interval),
1385 		.mode		= 0644,
1386 		.proc_handler	= proc_dointvec_jiffies,
1387 	},
1388 #endif
1389 #ifdef CONFIG_MMU
1390 	{
1391 		.procname	= "mmap_min_addr",
1392 		.data		= &dac_mmap_min_addr,
1393 		.maxlen		= sizeof(unsigned long),
1394 		.mode		= 0644,
1395 		.proc_handler	= mmap_min_addr_handler,
1396 	},
1397 #endif
1398 #ifdef CONFIG_NUMA
1399 	{
1400 		.procname	= "numa_zonelist_order",
1401 		.data		= &numa_zonelist_order,
1402 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1403 		.mode		= 0644,
1404 		.proc_handler	= numa_zonelist_order_handler,
1405 	},
1406 #endif
1407 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1408    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1409 	{
1410 		.procname	= "vdso_enabled",
1411 		.data		= &vdso_enabled,
1412 		.maxlen		= sizeof(vdso_enabled),
1413 		.mode		= 0644,
1414 		.proc_handler	= proc_dointvec,
1415 		.extra1		= &zero,
1416 	},
1417 #endif
1418 #ifdef CONFIG_HIGHMEM
1419 	{
1420 		.procname	= "highmem_is_dirtyable",
1421 		.data		= &vm_highmem_is_dirtyable,
1422 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1423 		.mode		= 0644,
1424 		.proc_handler	= proc_dointvec_minmax,
1425 		.extra1		= &zero,
1426 		.extra2		= &one,
1427 	},
1428 #endif
1429 	{
1430 		.procname	= "scan_unevictable_pages",
1431 		.data		= &scan_unevictable_pages,
1432 		.maxlen		= sizeof(scan_unevictable_pages),
1433 		.mode		= 0644,
1434 		.proc_handler	= scan_unevictable_handler,
1435 	},
1436 #ifdef CONFIG_MEMORY_FAILURE
1437 	{
1438 		.procname	= "memory_failure_early_kill",
1439 		.data		= &sysctl_memory_failure_early_kill,
1440 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1441 		.mode		= 0644,
1442 		.proc_handler	= proc_dointvec_minmax,
1443 		.extra1		= &zero,
1444 		.extra2		= &one,
1445 	},
1446 	{
1447 		.procname	= "memory_failure_recovery",
1448 		.data		= &sysctl_memory_failure_recovery,
1449 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1450 		.mode		= 0644,
1451 		.proc_handler	= proc_dointvec_minmax,
1452 		.extra1		= &zero,
1453 		.extra2		= &one,
1454 	},
1455 #endif
1456 	{
1457 		.procname	= "user_reserve_kbytes",
1458 		.data		= &sysctl_user_reserve_kbytes,
1459 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1460 		.mode		= 0644,
1461 		.proc_handler	= proc_doulongvec_minmax,
1462 	},
1463 	{
1464 		.procname	= "admin_reserve_kbytes",
1465 		.data		= &sysctl_admin_reserve_kbytes,
1466 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1467 		.mode		= 0644,
1468 		.proc_handler	= proc_doulongvec_minmax,
1469 	},
1470 	{ }
1471 };
1472 
1473 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1474 static struct ctl_table binfmt_misc_table[] = {
1475 	{ }
1476 };
1477 #endif
1478 
1479 static struct ctl_table fs_table[] = {
1480 	{
1481 		.procname	= "inode-nr",
1482 		.data		= &inodes_stat,
1483 		.maxlen		= 2*sizeof(long),
1484 		.mode		= 0444,
1485 		.proc_handler	= proc_nr_inodes,
1486 	},
1487 	{
1488 		.procname	= "inode-state",
1489 		.data		= &inodes_stat,
1490 		.maxlen		= 7*sizeof(long),
1491 		.mode		= 0444,
1492 		.proc_handler	= proc_nr_inodes,
1493 	},
1494 	{
1495 		.procname	= "file-nr",
1496 		.data		= &files_stat,
1497 		.maxlen		= sizeof(files_stat),
1498 		.mode		= 0444,
1499 		.proc_handler	= proc_nr_files,
1500 	},
1501 	{
1502 		.procname	= "file-max",
1503 		.data		= &files_stat.max_files,
1504 		.maxlen		= sizeof(files_stat.max_files),
1505 		.mode		= 0644,
1506 		.proc_handler	= proc_doulongvec_minmax,
1507 	},
1508 	{
1509 		.procname	= "nr_open",
1510 		.data		= &sysctl_nr_open,
1511 		.maxlen		= sizeof(int),
1512 		.mode		= 0644,
1513 		.proc_handler	= proc_dointvec_minmax,
1514 		.extra1		= &sysctl_nr_open_min,
1515 		.extra2		= &sysctl_nr_open_max,
1516 	},
1517 	{
1518 		.procname	= "dentry-state",
1519 		.data		= &dentry_stat,
1520 		.maxlen		= 6*sizeof(long),
1521 		.mode		= 0444,
1522 		.proc_handler	= proc_nr_dentry,
1523 	},
1524 	{
1525 		.procname	= "overflowuid",
1526 		.data		= &fs_overflowuid,
1527 		.maxlen		= sizeof(int),
1528 		.mode		= 0644,
1529 		.proc_handler	= proc_dointvec_minmax,
1530 		.extra1		= &minolduid,
1531 		.extra2		= &maxolduid,
1532 	},
1533 	{
1534 		.procname	= "overflowgid",
1535 		.data		= &fs_overflowgid,
1536 		.maxlen		= sizeof(int),
1537 		.mode		= 0644,
1538 		.proc_handler	= proc_dointvec_minmax,
1539 		.extra1		= &minolduid,
1540 		.extra2		= &maxolduid,
1541 	},
1542 #ifdef CONFIG_FILE_LOCKING
1543 	{
1544 		.procname	= "leases-enable",
1545 		.data		= &leases_enable,
1546 		.maxlen		= sizeof(int),
1547 		.mode		= 0644,
1548 		.proc_handler	= proc_dointvec,
1549 	},
1550 #endif
1551 #ifdef CONFIG_DNOTIFY
1552 	{
1553 		.procname	= "dir-notify-enable",
1554 		.data		= &dir_notify_enable,
1555 		.maxlen		= sizeof(int),
1556 		.mode		= 0644,
1557 		.proc_handler	= proc_dointvec,
1558 	},
1559 #endif
1560 #ifdef CONFIG_MMU
1561 #ifdef CONFIG_FILE_LOCKING
1562 	{
1563 		.procname	= "lease-break-time",
1564 		.data		= &lease_break_time,
1565 		.maxlen		= sizeof(int),
1566 		.mode		= 0644,
1567 		.proc_handler	= proc_dointvec,
1568 	},
1569 #endif
1570 #ifdef CONFIG_AIO
1571 	{
1572 		.procname	= "aio-nr",
1573 		.data		= &aio_nr,
1574 		.maxlen		= sizeof(aio_nr),
1575 		.mode		= 0444,
1576 		.proc_handler	= proc_doulongvec_minmax,
1577 	},
1578 	{
1579 		.procname	= "aio-max-nr",
1580 		.data		= &aio_max_nr,
1581 		.maxlen		= sizeof(aio_max_nr),
1582 		.mode		= 0644,
1583 		.proc_handler	= proc_doulongvec_minmax,
1584 	},
1585 #endif /* CONFIG_AIO */
1586 #ifdef CONFIG_INOTIFY_USER
1587 	{
1588 		.procname	= "inotify",
1589 		.mode		= 0555,
1590 		.child		= inotify_table,
1591 	},
1592 #endif
1593 #ifdef CONFIG_EPOLL
1594 	{
1595 		.procname	= "epoll",
1596 		.mode		= 0555,
1597 		.child		= epoll_table,
1598 	},
1599 #endif
1600 #endif
1601 	{
1602 		.procname	= "protected_symlinks",
1603 		.data		= &sysctl_protected_symlinks,
1604 		.maxlen		= sizeof(int),
1605 		.mode		= 0600,
1606 		.proc_handler	= proc_dointvec_minmax,
1607 		.extra1		= &zero,
1608 		.extra2		= &one,
1609 	},
1610 	{
1611 		.procname	= "protected_hardlinks",
1612 		.data		= &sysctl_protected_hardlinks,
1613 		.maxlen		= sizeof(int),
1614 		.mode		= 0600,
1615 		.proc_handler	= proc_dointvec_minmax,
1616 		.extra1		= &zero,
1617 		.extra2		= &one,
1618 	},
1619 	{
1620 		.procname	= "suid_dumpable",
1621 		.data		= &suid_dumpable,
1622 		.maxlen		= sizeof(int),
1623 		.mode		= 0644,
1624 		.proc_handler	= proc_dointvec_minmax_coredump,
1625 		.extra1		= &zero,
1626 		.extra2		= &two,
1627 	},
1628 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1629 	{
1630 		.procname	= "binfmt_misc",
1631 		.mode		= 0555,
1632 		.child		= binfmt_misc_table,
1633 	},
1634 #endif
1635 	{
1636 		.procname	= "pipe-max-size",
1637 		.data		= &pipe_max_size,
1638 		.maxlen		= sizeof(int),
1639 		.mode		= 0644,
1640 		.proc_handler	= &pipe_proc_fn,
1641 		.extra1		= &pipe_min_size,
1642 	},
1643 	{ }
1644 };
1645 
1646 static struct ctl_table debug_table[] = {
1647 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1648 	{
1649 		.procname	= "exception-trace",
1650 		.data		= &show_unhandled_signals,
1651 		.maxlen		= sizeof(int),
1652 		.mode		= 0644,
1653 		.proc_handler	= proc_dointvec
1654 	},
1655 #endif
1656 #if defined(CONFIG_OPTPROBES)
1657 	{
1658 		.procname	= "kprobes-optimization",
1659 		.data		= &sysctl_kprobes_optimization,
1660 		.maxlen		= sizeof(int),
1661 		.mode		= 0644,
1662 		.proc_handler	= proc_kprobes_optimization_handler,
1663 		.extra1		= &zero,
1664 		.extra2		= &one,
1665 	},
1666 #endif
1667 	{ }
1668 };
1669 
1670 static struct ctl_table dev_table[] = {
1671 	{ }
1672 };
1673 
1674 int __init sysctl_init(void)
1675 {
1676 	struct ctl_table_header *hdr;
1677 
1678 	hdr = register_sysctl_table(sysctl_base_table);
1679 	kmemleak_not_leak(hdr);
1680 	return 0;
1681 }
1682 
1683 #endif /* CONFIG_SYSCTL */
1684 
1685 /*
1686  * /proc/sys support
1687  */
1688 
1689 #ifdef CONFIG_PROC_SYSCTL
1690 
1691 static int _proc_do_string(void* data, int maxlen, int write,
1692 			   void __user *buffer,
1693 			   size_t *lenp, loff_t *ppos)
1694 {
1695 	size_t len;
1696 	char __user *p;
1697 	char c;
1698 
1699 	if (!data || !maxlen || !*lenp) {
1700 		*lenp = 0;
1701 		return 0;
1702 	}
1703 
1704 	if (write) {
1705 		len = 0;
1706 		p = buffer;
1707 		while (len < *lenp) {
1708 			if (get_user(c, p++))
1709 				return -EFAULT;
1710 			if (c == 0 || c == '\n')
1711 				break;
1712 			len++;
1713 		}
1714 		if (len >= maxlen)
1715 			len = maxlen-1;
1716 		if(copy_from_user(data, buffer, len))
1717 			return -EFAULT;
1718 		((char *) data)[len] = 0;
1719 		*ppos += *lenp;
1720 	} else {
1721 		len = strlen(data);
1722 		if (len > maxlen)
1723 			len = maxlen;
1724 
1725 		if (*ppos > len) {
1726 			*lenp = 0;
1727 			return 0;
1728 		}
1729 
1730 		data += *ppos;
1731 		len  -= *ppos;
1732 
1733 		if (len > *lenp)
1734 			len = *lenp;
1735 		if (len)
1736 			if(copy_to_user(buffer, data, len))
1737 				return -EFAULT;
1738 		if (len < *lenp) {
1739 			if(put_user('\n', ((char __user *) buffer) + len))
1740 				return -EFAULT;
1741 			len++;
1742 		}
1743 		*lenp = len;
1744 		*ppos += len;
1745 	}
1746 	return 0;
1747 }
1748 
1749 /**
1750  * proc_dostring - read a string sysctl
1751  * @table: the sysctl table
1752  * @write: %TRUE if this is a write to the sysctl file
1753  * @buffer: the user buffer
1754  * @lenp: the size of the user buffer
1755  * @ppos: file position
1756  *
1757  * Reads/writes a string from/to the user buffer. If the kernel
1758  * buffer provided is not large enough to hold the string, the
1759  * string is truncated. The copied string is %NULL-terminated.
1760  * If the string is being read by the user process, it is copied
1761  * and a newline '\n' is added. It is truncated if the buffer is
1762  * not large enough.
1763  *
1764  * Returns 0 on success.
1765  */
1766 int proc_dostring(struct ctl_table *table, int write,
1767 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1768 {
1769 	return _proc_do_string(table->data, table->maxlen, write,
1770 			       buffer, lenp, ppos);
1771 }
1772 
1773 static size_t proc_skip_spaces(char **buf)
1774 {
1775 	size_t ret;
1776 	char *tmp = skip_spaces(*buf);
1777 	ret = tmp - *buf;
1778 	*buf = tmp;
1779 	return ret;
1780 }
1781 
1782 static void proc_skip_char(char **buf, size_t *size, const char v)
1783 {
1784 	while (*size) {
1785 		if (**buf != v)
1786 			break;
1787 		(*size)--;
1788 		(*buf)++;
1789 	}
1790 }
1791 
1792 #define TMPBUFLEN 22
1793 /**
1794  * proc_get_long - reads an ASCII formatted integer from a user buffer
1795  *
1796  * @buf: a kernel buffer
1797  * @size: size of the kernel buffer
1798  * @val: this is where the number will be stored
1799  * @neg: set to %TRUE if number is negative
1800  * @perm_tr: a vector which contains the allowed trailers
1801  * @perm_tr_len: size of the perm_tr vector
1802  * @tr: pointer to store the trailer character
1803  *
1804  * In case of success %0 is returned and @buf and @size are updated with
1805  * the amount of bytes read. If @tr is non-NULL and a trailing
1806  * character exists (size is non-zero after returning from this
1807  * function), @tr is updated with the trailing character.
1808  */
1809 static int proc_get_long(char **buf, size_t *size,
1810 			  unsigned long *val, bool *neg,
1811 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
1812 {
1813 	int len;
1814 	char *p, tmp[TMPBUFLEN];
1815 
1816 	if (!*size)
1817 		return -EINVAL;
1818 
1819 	len = *size;
1820 	if (len > TMPBUFLEN - 1)
1821 		len = TMPBUFLEN - 1;
1822 
1823 	memcpy(tmp, *buf, len);
1824 
1825 	tmp[len] = 0;
1826 	p = tmp;
1827 	if (*p == '-' && *size > 1) {
1828 		*neg = true;
1829 		p++;
1830 	} else
1831 		*neg = false;
1832 	if (!isdigit(*p))
1833 		return -EINVAL;
1834 
1835 	*val = simple_strtoul(p, &p, 0);
1836 
1837 	len = p - tmp;
1838 
1839 	/* We don't know if the next char is whitespace thus we may accept
1840 	 * invalid integers (e.g. 1234...a) or two integers instead of one
1841 	 * (e.g. 123...1). So lets not allow such large numbers. */
1842 	if (len == TMPBUFLEN - 1)
1843 		return -EINVAL;
1844 
1845 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
1846 		return -EINVAL;
1847 
1848 	if (tr && (len < *size))
1849 		*tr = *p;
1850 
1851 	*buf += len;
1852 	*size -= len;
1853 
1854 	return 0;
1855 }
1856 
1857 /**
1858  * proc_put_long - converts an integer to a decimal ASCII formatted string
1859  *
1860  * @buf: the user buffer
1861  * @size: the size of the user buffer
1862  * @val: the integer to be converted
1863  * @neg: sign of the number, %TRUE for negative
1864  *
1865  * In case of success %0 is returned and @buf and @size are updated with
1866  * the amount of bytes written.
1867  */
1868 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
1869 			  bool neg)
1870 {
1871 	int len;
1872 	char tmp[TMPBUFLEN], *p = tmp;
1873 
1874 	sprintf(p, "%s%lu", neg ? "-" : "", val);
1875 	len = strlen(tmp);
1876 	if (len > *size)
1877 		len = *size;
1878 	if (copy_to_user(*buf, tmp, len))
1879 		return -EFAULT;
1880 	*size -= len;
1881 	*buf += len;
1882 	return 0;
1883 }
1884 #undef TMPBUFLEN
1885 
1886 static int proc_put_char(void __user **buf, size_t *size, char c)
1887 {
1888 	if (*size) {
1889 		char __user **buffer = (char __user **)buf;
1890 		if (put_user(c, *buffer))
1891 			return -EFAULT;
1892 		(*size)--, (*buffer)++;
1893 		*buf = *buffer;
1894 	}
1895 	return 0;
1896 }
1897 
1898 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
1899 				 int *valp,
1900 				 int write, void *data)
1901 {
1902 	if (write) {
1903 		*valp = *negp ? -*lvalp : *lvalp;
1904 	} else {
1905 		int val = *valp;
1906 		if (val < 0) {
1907 			*negp = true;
1908 			*lvalp = (unsigned long)-val;
1909 		} else {
1910 			*negp = false;
1911 			*lvalp = (unsigned long)val;
1912 		}
1913 	}
1914 	return 0;
1915 }
1916 
1917 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
1918 
1919 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
1920 		  int write, void __user *buffer,
1921 		  size_t *lenp, loff_t *ppos,
1922 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
1923 			      int write, void *data),
1924 		  void *data)
1925 {
1926 	int *i, vleft, first = 1, err = 0;
1927 	unsigned long page = 0;
1928 	size_t left;
1929 	char *kbuf;
1930 
1931 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
1932 		*lenp = 0;
1933 		return 0;
1934 	}
1935 
1936 	i = (int *) tbl_data;
1937 	vleft = table->maxlen / sizeof(*i);
1938 	left = *lenp;
1939 
1940 	if (!conv)
1941 		conv = do_proc_dointvec_conv;
1942 
1943 	if (write) {
1944 		if (left > PAGE_SIZE - 1)
1945 			left = PAGE_SIZE - 1;
1946 		page = __get_free_page(GFP_TEMPORARY);
1947 		kbuf = (char *) page;
1948 		if (!kbuf)
1949 			return -ENOMEM;
1950 		if (copy_from_user(kbuf, buffer, left)) {
1951 			err = -EFAULT;
1952 			goto free;
1953 		}
1954 		kbuf[left] = 0;
1955 	}
1956 
1957 	for (; left && vleft--; i++, first=0) {
1958 		unsigned long lval;
1959 		bool neg;
1960 
1961 		if (write) {
1962 			left -= proc_skip_spaces(&kbuf);
1963 
1964 			if (!left)
1965 				break;
1966 			err = proc_get_long(&kbuf, &left, &lval, &neg,
1967 					     proc_wspace_sep,
1968 					     sizeof(proc_wspace_sep), NULL);
1969 			if (err)
1970 				break;
1971 			if (conv(&neg, &lval, i, 1, data)) {
1972 				err = -EINVAL;
1973 				break;
1974 			}
1975 		} else {
1976 			if (conv(&neg, &lval, i, 0, data)) {
1977 				err = -EINVAL;
1978 				break;
1979 			}
1980 			if (!first)
1981 				err = proc_put_char(&buffer, &left, '\t');
1982 			if (err)
1983 				break;
1984 			err = proc_put_long(&buffer, &left, lval, neg);
1985 			if (err)
1986 				break;
1987 		}
1988 	}
1989 
1990 	if (!write && !first && left && !err)
1991 		err = proc_put_char(&buffer, &left, '\n');
1992 	if (write && !err && left)
1993 		left -= proc_skip_spaces(&kbuf);
1994 free:
1995 	if (write) {
1996 		free_page(page);
1997 		if (first)
1998 			return err ? : -EINVAL;
1999 	}
2000 	*lenp -= left;
2001 	*ppos += *lenp;
2002 	return err;
2003 }
2004 
2005 static int do_proc_dointvec(struct ctl_table *table, int write,
2006 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2007 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2008 			      int write, void *data),
2009 		  void *data)
2010 {
2011 	return __do_proc_dointvec(table->data, table, write,
2012 			buffer, lenp, ppos, conv, data);
2013 }
2014 
2015 /**
2016  * proc_dointvec - read a vector of integers
2017  * @table: the sysctl table
2018  * @write: %TRUE if this is a write to the sysctl file
2019  * @buffer: the user buffer
2020  * @lenp: the size of the user buffer
2021  * @ppos: file position
2022  *
2023  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2024  * values from/to the user buffer, treated as an ASCII string.
2025  *
2026  * Returns 0 on success.
2027  */
2028 int proc_dointvec(struct ctl_table *table, int write,
2029 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2030 {
2031     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2032 		    	    NULL,NULL);
2033 }
2034 
2035 /*
2036  * Taint values can only be increased
2037  * This means we can safely use a temporary.
2038  */
2039 static int proc_taint(struct ctl_table *table, int write,
2040 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2041 {
2042 	struct ctl_table t;
2043 	unsigned long tmptaint = get_taint();
2044 	int err;
2045 
2046 	if (write && !capable(CAP_SYS_ADMIN))
2047 		return -EPERM;
2048 
2049 	t = *table;
2050 	t.data = &tmptaint;
2051 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2052 	if (err < 0)
2053 		return err;
2054 
2055 	if (write) {
2056 		/*
2057 		 * Poor man's atomic or. Not worth adding a primitive
2058 		 * to everyone's atomic.h for this
2059 		 */
2060 		int i;
2061 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2062 			if ((tmptaint >> i) & 1)
2063 				add_taint(i, LOCKDEP_STILL_OK);
2064 		}
2065 	}
2066 
2067 	return err;
2068 }
2069 
2070 #ifdef CONFIG_PRINTK
2071 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2072 				void __user *buffer, size_t *lenp, loff_t *ppos)
2073 {
2074 	if (write && !capable(CAP_SYS_ADMIN))
2075 		return -EPERM;
2076 
2077 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2078 }
2079 #endif
2080 
2081 struct do_proc_dointvec_minmax_conv_param {
2082 	int *min;
2083 	int *max;
2084 };
2085 
2086 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2087 					int *valp,
2088 					int write, void *data)
2089 {
2090 	struct do_proc_dointvec_minmax_conv_param *param = data;
2091 	if (write) {
2092 		int val = *negp ? -*lvalp : *lvalp;
2093 		if ((param->min && *param->min > val) ||
2094 		    (param->max && *param->max < val))
2095 			return -EINVAL;
2096 		*valp = val;
2097 	} else {
2098 		int val = *valp;
2099 		if (val < 0) {
2100 			*negp = true;
2101 			*lvalp = (unsigned long)-val;
2102 		} else {
2103 			*negp = false;
2104 			*lvalp = (unsigned long)val;
2105 		}
2106 	}
2107 	return 0;
2108 }
2109 
2110 /**
2111  * proc_dointvec_minmax - read a vector of integers with min/max values
2112  * @table: the sysctl table
2113  * @write: %TRUE if this is a write to the sysctl file
2114  * @buffer: the user buffer
2115  * @lenp: the size of the user buffer
2116  * @ppos: file position
2117  *
2118  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2119  * values from/to the user buffer, treated as an ASCII string.
2120  *
2121  * This routine will ensure the values are within the range specified by
2122  * table->extra1 (min) and table->extra2 (max).
2123  *
2124  * Returns 0 on success.
2125  */
2126 int proc_dointvec_minmax(struct ctl_table *table, int write,
2127 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2128 {
2129 	struct do_proc_dointvec_minmax_conv_param param = {
2130 		.min = (int *) table->extra1,
2131 		.max = (int *) table->extra2,
2132 	};
2133 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2134 				do_proc_dointvec_minmax_conv, &param);
2135 }
2136 
2137 static void validate_coredump_safety(void)
2138 {
2139 #ifdef CONFIG_COREDUMP
2140 	if (suid_dumpable == SUID_DUMP_ROOT &&
2141 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2142 		printk(KERN_WARNING "Unsafe core_pattern used with "\
2143 			"suid_dumpable=2. Pipe handler or fully qualified "\
2144 			"core dump path required.\n");
2145 	}
2146 #endif
2147 }
2148 
2149 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2150 		void __user *buffer, size_t *lenp, loff_t *ppos)
2151 {
2152 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2153 	if (!error)
2154 		validate_coredump_safety();
2155 	return error;
2156 }
2157 
2158 #ifdef CONFIG_COREDUMP
2159 static int proc_dostring_coredump(struct ctl_table *table, int write,
2160 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2161 {
2162 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2163 	if (!error)
2164 		validate_coredump_safety();
2165 	return error;
2166 }
2167 #endif
2168 
2169 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2170 				     void __user *buffer,
2171 				     size_t *lenp, loff_t *ppos,
2172 				     unsigned long convmul,
2173 				     unsigned long convdiv)
2174 {
2175 	unsigned long *i, *min, *max;
2176 	int vleft, first = 1, err = 0;
2177 	unsigned long page = 0;
2178 	size_t left;
2179 	char *kbuf;
2180 
2181 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2182 		*lenp = 0;
2183 		return 0;
2184 	}
2185 
2186 	i = (unsigned long *) data;
2187 	min = (unsigned long *) table->extra1;
2188 	max = (unsigned long *) table->extra2;
2189 	vleft = table->maxlen / sizeof(unsigned long);
2190 	left = *lenp;
2191 
2192 	if (write) {
2193 		if (left > PAGE_SIZE - 1)
2194 			left = PAGE_SIZE - 1;
2195 		page = __get_free_page(GFP_TEMPORARY);
2196 		kbuf = (char *) page;
2197 		if (!kbuf)
2198 			return -ENOMEM;
2199 		if (copy_from_user(kbuf, buffer, left)) {
2200 			err = -EFAULT;
2201 			goto free;
2202 		}
2203 		kbuf[left] = 0;
2204 	}
2205 
2206 	for (; left && vleft--; i++, first = 0) {
2207 		unsigned long val;
2208 
2209 		if (write) {
2210 			bool neg;
2211 
2212 			left -= proc_skip_spaces(&kbuf);
2213 
2214 			err = proc_get_long(&kbuf, &left, &val, &neg,
2215 					     proc_wspace_sep,
2216 					     sizeof(proc_wspace_sep), NULL);
2217 			if (err)
2218 				break;
2219 			if (neg)
2220 				continue;
2221 			if ((min && val < *min) || (max && val > *max))
2222 				continue;
2223 			*i = val;
2224 		} else {
2225 			val = convdiv * (*i) / convmul;
2226 			if (!first) {
2227 				err = proc_put_char(&buffer, &left, '\t');
2228 				if (err)
2229 					break;
2230 			}
2231 			err = proc_put_long(&buffer, &left, val, false);
2232 			if (err)
2233 				break;
2234 		}
2235 	}
2236 
2237 	if (!write && !first && left && !err)
2238 		err = proc_put_char(&buffer, &left, '\n');
2239 	if (write && !err)
2240 		left -= proc_skip_spaces(&kbuf);
2241 free:
2242 	if (write) {
2243 		free_page(page);
2244 		if (first)
2245 			return err ? : -EINVAL;
2246 	}
2247 	*lenp -= left;
2248 	*ppos += *lenp;
2249 	return err;
2250 }
2251 
2252 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2253 				     void __user *buffer,
2254 				     size_t *lenp, loff_t *ppos,
2255 				     unsigned long convmul,
2256 				     unsigned long convdiv)
2257 {
2258 	return __do_proc_doulongvec_minmax(table->data, table, write,
2259 			buffer, lenp, ppos, convmul, convdiv);
2260 }
2261 
2262 /**
2263  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2264  * @table: the sysctl table
2265  * @write: %TRUE if this is a write to the sysctl file
2266  * @buffer: the user buffer
2267  * @lenp: the size of the user buffer
2268  * @ppos: file position
2269  *
2270  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2271  * values from/to the user buffer, treated as an ASCII string.
2272  *
2273  * This routine will ensure the values are within the range specified by
2274  * table->extra1 (min) and table->extra2 (max).
2275  *
2276  * Returns 0 on success.
2277  */
2278 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2279 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2280 {
2281     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2282 }
2283 
2284 /**
2285  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2286  * @table: the sysctl table
2287  * @write: %TRUE if this is a write to the sysctl file
2288  * @buffer: the user buffer
2289  * @lenp: the size of the user buffer
2290  * @ppos: file position
2291  *
2292  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2293  * values from/to the user buffer, treated as an ASCII string. The values
2294  * are treated as milliseconds, and converted to jiffies when they are stored.
2295  *
2296  * This routine will ensure the values are within the range specified by
2297  * table->extra1 (min) and table->extra2 (max).
2298  *
2299  * Returns 0 on success.
2300  */
2301 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2302 				      void __user *buffer,
2303 				      size_t *lenp, loff_t *ppos)
2304 {
2305     return do_proc_doulongvec_minmax(table, write, buffer,
2306 				     lenp, ppos, HZ, 1000l);
2307 }
2308 
2309 
2310 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2311 					 int *valp,
2312 					 int write, void *data)
2313 {
2314 	if (write) {
2315 		if (*lvalp > LONG_MAX / HZ)
2316 			return 1;
2317 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2318 	} else {
2319 		int val = *valp;
2320 		unsigned long lval;
2321 		if (val < 0) {
2322 			*negp = true;
2323 			lval = (unsigned long)-val;
2324 		} else {
2325 			*negp = false;
2326 			lval = (unsigned long)val;
2327 		}
2328 		*lvalp = lval / HZ;
2329 	}
2330 	return 0;
2331 }
2332 
2333 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2334 						int *valp,
2335 						int write, void *data)
2336 {
2337 	if (write) {
2338 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2339 			return 1;
2340 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2341 	} else {
2342 		int val = *valp;
2343 		unsigned long lval;
2344 		if (val < 0) {
2345 			*negp = true;
2346 			lval = (unsigned long)-val;
2347 		} else {
2348 			*negp = false;
2349 			lval = (unsigned long)val;
2350 		}
2351 		*lvalp = jiffies_to_clock_t(lval);
2352 	}
2353 	return 0;
2354 }
2355 
2356 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2357 					    int *valp,
2358 					    int write, void *data)
2359 {
2360 	if (write) {
2361 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2362 
2363 		if (jif > INT_MAX)
2364 			return 1;
2365 		*valp = (int)jif;
2366 	} else {
2367 		int val = *valp;
2368 		unsigned long lval;
2369 		if (val < 0) {
2370 			*negp = true;
2371 			lval = (unsigned long)-val;
2372 		} else {
2373 			*negp = false;
2374 			lval = (unsigned long)val;
2375 		}
2376 		*lvalp = jiffies_to_msecs(lval);
2377 	}
2378 	return 0;
2379 }
2380 
2381 /**
2382  * proc_dointvec_jiffies - read a vector of integers as seconds
2383  * @table: the sysctl table
2384  * @write: %TRUE if this is a write to the sysctl file
2385  * @buffer: the user buffer
2386  * @lenp: the size of the user buffer
2387  * @ppos: file position
2388  *
2389  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2390  * values from/to the user buffer, treated as an ASCII string.
2391  * The values read are assumed to be in seconds, and are converted into
2392  * jiffies.
2393  *
2394  * Returns 0 on success.
2395  */
2396 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2397 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2398 {
2399     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2400 		    	    do_proc_dointvec_jiffies_conv,NULL);
2401 }
2402 
2403 /**
2404  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2405  * @table: the sysctl table
2406  * @write: %TRUE if this is a write to the sysctl file
2407  * @buffer: the user buffer
2408  * @lenp: the size of the user buffer
2409  * @ppos: pointer to the file position
2410  *
2411  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2412  * values from/to the user buffer, treated as an ASCII string.
2413  * The values read are assumed to be in 1/USER_HZ seconds, and
2414  * are converted into jiffies.
2415  *
2416  * Returns 0 on success.
2417  */
2418 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2419 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2420 {
2421     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2422 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2423 }
2424 
2425 /**
2426  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2427  * @table: the sysctl table
2428  * @write: %TRUE if this is a write to the sysctl file
2429  * @buffer: the user buffer
2430  * @lenp: the size of the user buffer
2431  * @ppos: file position
2432  * @ppos: the current position in the file
2433  *
2434  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2435  * values from/to the user buffer, treated as an ASCII string.
2436  * The values read are assumed to be in 1/1000 seconds, and
2437  * are converted into jiffies.
2438  *
2439  * Returns 0 on success.
2440  */
2441 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2442 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2443 {
2444 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2445 				do_proc_dointvec_ms_jiffies_conv, NULL);
2446 }
2447 
2448 static int proc_do_cad_pid(struct ctl_table *table, int write,
2449 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2450 {
2451 	struct pid *new_pid;
2452 	pid_t tmp;
2453 	int r;
2454 
2455 	tmp = pid_vnr(cad_pid);
2456 
2457 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2458 			       lenp, ppos, NULL, NULL);
2459 	if (r || !write)
2460 		return r;
2461 
2462 	new_pid = find_get_pid(tmp);
2463 	if (!new_pid)
2464 		return -ESRCH;
2465 
2466 	put_pid(xchg(&cad_pid, new_pid));
2467 	return 0;
2468 }
2469 
2470 /**
2471  * proc_do_large_bitmap - read/write from/to a large bitmap
2472  * @table: the sysctl table
2473  * @write: %TRUE if this is a write to the sysctl file
2474  * @buffer: the user buffer
2475  * @lenp: the size of the user buffer
2476  * @ppos: file position
2477  *
2478  * The bitmap is stored at table->data and the bitmap length (in bits)
2479  * in table->maxlen.
2480  *
2481  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2482  * large bitmaps may be represented in a compact manner. Writing into
2483  * the file will clear the bitmap then update it with the given input.
2484  *
2485  * Returns 0 on success.
2486  */
2487 int proc_do_large_bitmap(struct ctl_table *table, int write,
2488 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2489 {
2490 	int err = 0;
2491 	bool first = 1;
2492 	size_t left = *lenp;
2493 	unsigned long bitmap_len = table->maxlen;
2494 	unsigned long *bitmap = (unsigned long *) table->data;
2495 	unsigned long *tmp_bitmap = NULL;
2496 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2497 
2498 	if (!bitmap_len || !left || (*ppos && !write)) {
2499 		*lenp = 0;
2500 		return 0;
2501 	}
2502 
2503 	if (write) {
2504 		unsigned long page = 0;
2505 		char *kbuf;
2506 
2507 		if (left > PAGE_SIZE - 1)
2508 			left = PAGE_SIZE - 1;
2509 
2510 		page = __get_free_page(GFP_TEMPORARY);
2511 		kbuf = (char *) page;
2512 		if (!kbuf)
2513 			return -ENOMEM;
2514 		if (copy_from_user(kbuf, buffer, left)) {
2515 			free_page(page);
2516 			return -EFAULT;
2517                 }
2518 		kbuf[left] = 0;
2519 
2520 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2521 				     GFP_KERNEL);
2522 		if (!tmp_bitmap) {
2523 			free_page(page);
2524 			return -ENOMEM;
2525 		}
2526 		proc_skip_char(&kbuf, &left, '\n');
2527 		while (!err && left) {
2528 			unsigned long val_a, val_b;
2529 			bool neg;
2530 
2531 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2532 					     sizeof(tr_a), &c);
2533 			if (err)
2534 				break;
2535 			if (val_a >= bitmap_len || neg) {
2536 				err = -EINVAL;
2537 				break;
2538 			}
2539 
2540 			val_b = val_a;
2541 			if (left) {
2542 				kbuf++;
2543 				left--;
2544 			}
2545 
2546 			if (c == '-') {
2547 				err = proc_get_long(&kbuf, &left, &val_b,
2548 						     &neg, tr_b, sizeof(tr_b),
2549 						     &c);
2550 				if (err)
2551 					break;
2552 				if (val_b >= bitmap_len || neg ||
2553 				    val_a > val_b) {
2554 					err = -EINVAL;
2555 					break;
2556 				}
2557 				if (left) {
2558 					kbuf++;
2559 					left--;
2560 				}
2561 			}
2562 
2563 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2564 			first = 0;
2565 			proc_skip_char(&kbuf, &left, '\n');
2566 		}
2567 		free_page(page);
2568 	} else {
2569 		unsigned long bit_a, bit_b = 0;
2570 
2571 		while (left) {
2572 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2573 			if (bit_a >= bitmap_len)
2574 				break;
2575 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2576 						   bit_a + 1) - 1;
2577 
2578 			if (!first) {
2579 				err = proc_put_char(&buffer, &left, ',');
2580 				if (err)
2581 					break;
2582 			}
2583 			err = proc_put_long(&buffer, &left, bit_a, false);
2584 			if (err)
2585 				break;
2586 			if (bit_a != bit_b) {
2587 				err = proc_put_char(&buffer, &left, '-');
2588 				if (err)
2589 					break;
2590 				err = proc_put_long(&buffer, &left, bit_b, false);
2591 				if (err)
2592 					break;
2593 			}
2594 
2595 			first = 0; bit_b++;
2596 		}
2597 		if (!err)
2598 			err = proc_put_char(&buffer, &left, '\n');
2599 	}
2600 
2601 	if (!err) {
2602 		if (write) {
2603 			if (*ppos)
2604 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2605 			else
2606 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2607 		}
2608 		kfree(tmp_bitmap);
2609 		*lenp -= left;
2610 		*ppos += *lenp;
2611 		return 0;
2612 	} else {
2613 		kfree(tmp_bitmap);
2614 		return err;
2615 	}
2616 }
2617 
2618 #else /* CONFIG_PROC_SYSCTL */
2619 
2620 int proc_dostring(struct ctl_table *table, int write,
2621 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2622 {
2623 	return -ENOSYS;
2624 }
2625 
2626 int proc_dointvec(struct ctl_table *table, int write,
2627 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2628 {
2629 	return -ENOSYS;
2630 }
2631 
2632 int proc_dointvec_minmax(struct ctl_table *table, int write,
2633 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2634 {
2635 	return -ENOSYS;
2636 }
2637 
2638 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2639 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2640 {
2641 	return -ENOSYS;
2642 }
2643 
2644 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2645 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2646 {
2647 	return -ENOSYS;
2648 }
2649 
2650 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2651 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2652 {
2653 	return -ENOSYS;
2654 }
2655 
2656 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2657 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2658 {
2659 	return -ENOSYS;
2660 }
2661 
2662 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2663 				      void __user *buffer,
2664 				      size_t *lenp, loff_t *ppos)
2665 {
2666     return -ENOSYS;
2667 }
2668 
2669 
2670 #endif /* CONFIG_PROC_SYSCTL */
2671 
2672 /*
2673  * No sense putting this after each symbol definition, twice,
2674  * exception granted :-)
2675  */
2676 EXPORT_SYMBOL(proc_dointvec);
2677 EXPORT_SYMBOL(proc_dointvec_jiffies);
2678 EXPORT_SYMBOL(proc_dointvec_minmax);
2679 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2680 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2681 EXPORT_SYMBOL(proc_dostring);
2682 EXPORT_SYMBOL(proc_doulongvec_minmax);
2683 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2684