xref: /linux-6.15/kernel/sysctl.c (revision e9107f88)
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 #include <linux/kexec.h>
66 
67 #include <asm/uaccess.h>
68 #include <asm/processor.h>
69 
70 #ifdef CONFIG_X86
71 #include <asm/nmi.h>
72 #include <asm/stacktrace.h>
73 #include <asm/io.h>
74 #endif
75 #ifdef CONFIG_SPARC
76 #include <asm/setup.h>
77 #endif
78 #ifdef CONFIG_BSD_PROCESS_ACCT
79 #include <linux/acct.h>
80 #endif
81 #ifdef CONFIG_RT_MUTEXES
82 #include <linux/rtmutex.h>
83 #endif
84 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
85 #include <linux/lockdep.h>
86 #endif
87 #ifdef CONFIG_CHR_DEV_SG
88 #include <scsi/sg.h>
89 #endif
90 
91 #ifdef CONFIG_LOCKUP_DETECTOR
92 #include <linux/nmi.h>
93 #endif
94 
95 
96 #if defined(CONFIG_SYSCTL)
97 
98 /* External variables not in a header file. */
99 extern int max_threads;
100 extern int suid_dumpable;
101 #ifdef CONFIG_COREDUMP
102 extern int core_uses_pid;
103 extern char core_pattern[];
104 extern unsigned int core_pipe_limit;
105 #endif
106 extern int pid_max;
107 extern int pid_max_min, pid_max_max;
108 extern int percpu_pagelist_fraction;
109 extern int compat_log;
110 extern int latencytop_enabled;
111 extern int sysctl_nr_open_min, sysctl_nr_open_max;
112 #ifndef CONFIG_MMU
113 extern int sysctl_nr_trim_pages;
114 #endif
115 
116 /* Constants used for minimum and  maximum */
117 #ifdef CONFIG_LOCKUP_DETECTOR
118 static int sixty = 60;
119 #endif
120 
121 static int __maybe_unused neg_one = -1;
122 
123 static int zero;
124 static int __maybe_unused one = 1;
125 static int __maybe_unused two = 2;
126 static int __maybe_unused four = 4;
127 static unsigned long one_ul = 1;
128 static int one_hundred = 100;
129 #ifdef CONFIG_PRINTK
130 static int ten_thousand = 10000;
131 #endif
132 
133 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
134 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
135 
136 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
137 static int maxolduid = 65535;
138 static int minolduid;
139 static int min_percpu_pagelist_fract = 8;
140 
141 static int ngroups_max = NGROUPS_MAX;
142 static const int cap_last_cap = CAP_LAST_CAP;
143 
144 #ifdef CONFIG_INOTIFY_USER
145 #include <linux/inotify.h>
146 #endif
147 #ifdef CONFIG_SPARC
148 #endif
149 
150 #ifdef CONFIG_SPARC64
151 extern int sysctl_tsb_ratio;
152 #endif
153 
154 #ifdef __hppa__
155 extern int pwrsw_enabled;
156 #endif
157 
158 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
159 extern int unaligned_enabled;
160 #endif
161 
162 #ifdef CONFIG_IA64
163 extern int unaligned_dump_stack;
164 #endif
165 
166 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
167 extern int no_unaligned_warning;
168 #endif
169 
170 #ifdef CONFIG_PROC_SYSCTL
171 static int proc_do_cad_pid(struct ctl_table *table, int write,
172 		  void __user *buffer, size_t *lenp, loff_t *ppos);
173 static int proc_taint(struct ctl_table *table, int write,
174 			       void __user *buffer, size_t *lenp, loff_t *ppos);
175 #endif
176 
177 #ifdef CONFIG_PRINTK
178 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
179 				void __user *buffer, size_t *lenp, loff_t *ppos);
180 #endif
181 
182 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
183 		void __user *buffer, size_t *lenp, loff_t *ppos);
184 #ifdef CONFIG_COREDUMP
185 static int proc_dostring_coredump(struct ctl_table *table, int write,
186 		void __user *buffer, size_t *lenp, loff_t *ppos);
187 #endif
188 
189 #ifdef CONFIG_MAGIC_SYSRQ
190 /* Note: sysrq code uses it's own private copy */
191 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
192 
193 static int sysrq_sysctl_handler(ctl_table *table, int write,
194 				void __user *buffer, size_t *lenp,
195 				loff_t *ppos)
196 {
197 	int error;
198 
199 	error = proc_dointvec(table, write, buffer, lenp, ppos);
200 	if (error)
201 		return error;
202 
203 	if (write)
204 		sysrq_toggle_support(__sysrq_enabled);
205 
206 	return 0;
207 }
208 
209 #endif
210 
211 static struct ctl_table kern_table[];
212 static struct ctl_table vm_table[];
213 static struct ctl_table fs_table[];
214 static struct ctl_table debug_table[];
215 static struct ctl_table dev_table[];
216 extern struct ctl_table random_table[];
217 #ifdef CONFIG_EPOLL
218 extern struct ctl_table epoll_table[];
219 #endif
220 
221 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
222 int sysctl_legacy_va_layout;
223 #endif
224 
225 /* The default sysctl tables: */
226 
227 static struct ctl_table sysctl_base_table[] = {
228 	{
229 		.procname	= "kernel",
230 		.mode		= 0555,
231 		.child		= kern_table,
232 	},
233 	{
234 		.procname	= "vm",
235 		.mode		= 0555,
236 		.child		= vm_table,
237 	},
238 	{
239 		.procname	= "fs",
240 		.mode		= 0555,
241 		.child		= fs_table,
242 	},
243 	{
244 		.procname	= "debug",
245 		.mode		= 0555,
246 		.child		= debug_table,
247 	},
248 	{
249 		.procname	= "dev",
250 		.mode		= 0555,
251 		.child		= dev_table,
252 	},
253 	{ }
254 };
255 
256 #ifdef CONFIG_SCHED_DEBUG
257 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
258 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
259 static int min_wakeup_granularity_ns;			/* 0 usecs */
260 static int max_wakeup_granularity_ns = NSEC_PER_SEC;	/* 1 second */
261 #ifdef CONFIG_SMP
262 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
263 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
264 #endif /* CONFIG_SMP */
265 #endif /* CONFIG_SCHED_DEBUG */
266 
267 #ifdef CONFIG_COMPACTION
268 static int min_extfrag_threshold;
269 static int max_extfrag_threshold = 1000;
270 #endif
271 
272 static struct ctl_table kern_table[] = {
273 	{
274 		.procname	= "sched_child_runs_first",
275 		.data		= &sysctl_sched_child_runs_first,
276 		.maxlen		= sizeof(unsigned int),
277 		.mode		= 0644,
278 		.proc_handler	= proc_dointvec,
279 	},
280 #ifdef CONFIG_SCHED_DEBUG
281 	{
282 		.procname	= "sched_min_granularity_ns",
283 		.data		= &sysctl_sched_min_granularity,
284 		.maxlen		= sizeof(unsigned int),
285 		.mode		= 0644,
286 		.proc_handler	= sched_proc_update_handler,
287 		.extra1		= &min_sched_granularity_ns,
288 		.extra2		= &max_sched_granularity_ns,
289 	},
290 	{
291 		.procname	= "sched_latency_ns",
292 		.data		= &sysctl_sched_latency,
293 		.maxlen		= sizeof(unsigned int),
294 		.mode		= 0644,
295 		.proc_handler	= sched_proc_update_handler,
296 		.extra1		= &min_sched_granularity_ns,
297 		.extra2		= &max_sched_granularity_ns,
298 	},
299 	{
300 		.procname	= "sched_wakeup_granularity_ns",
301 		.data		= &sysctl_sched_wakeup_granularity,
302 		.maxlen		= sizeof(unsigned int),
303 		.mode		= 0644,
304 		.proc_handler	= sched_proc_update_handler,
305 		.extra1		= &min_wakeup_granularity_ns,
306 		.extra2		= &max_wakeup_granularity_ns,
307 	},
308 #ifdef CONFIG_SMP
309 	{
310 		.procname	= "sched_tunable_scaling",
311 		.data		= &sysctl_sched_tunable_scaling,
312 		.maxlen		= sizeof(enum sched_tunable_scaling),
313 		.mode		= 0644,
314 		.proc_handler	= sched_proc_update_handler,
315 		.extra1		= &min_sched_tunable_scaling,
316 		.extra2		= &max_sched_tunable_scaling,
317 	},
318 	{
319 		.procname	= "sched_migration_cost_ns",
320 		.data		= &sysctl_sched_migration_cost,
321 		.maxlen		= sizeof(unsigned int),
322 		.mode		= 0644,
323 		.proc_handler	= proc_dointvec,
324 	},
325 	{
326 		.procname	= "sched_nr_migrate",
327 		.data		= &sysctl_sched_nr_migrate,
328 		.maxlen		= sizeof(unsigned int),
329 		.mode		= 0644,
330 		.proc_handler	= proc_dointvec,
331 	},
332 	{
333 		.procname	= "sched_time_avg_ms",
334 		.data		= &sysctl_sched_time_avg,
335 		.maxlen		= sizeof(unsigned int),
336 		.mode		= 0644,
337 		.proc_handler	= proc_dointvec,
338 	},
339 	{
340 		.procname	= "sched_shares_window_ns",
341 		.data		= &sysctl_sched_shares_window,
342 		.maxlen		= sizeof(unsigned int),
343 		.mode		= 0644,
344 		.proc_handler	= proc_dointvec,
345 	},
346 	{
347 		.procname	= "timer_migration",
348 		.data		= &sysctl_timer_migration,
349 		.maxlen		= sizeof(unsigned int),
350 		.mode		= 0644,
351 		.proc_handler	= proc_dointvec_minmax,
352 		.extra1		= &zero,
353 		.extra2		= &one,
354 	},
355 #endif /* CONFIG_SMP */
356 #ifdef CONFIG_NUMA_BALANCING
357 	{
358 		.procname	= "numa_balancing_scan_delay_ms",
359 		.data		= &sysctl_numa_balancing_scan_delay,
360 		.maxlen		= sizeof(unsigned int),
361 		.mode		= 0644,
362 		.proc_handler	= proc_dointvec,
363 	},
364 	{
365 		.procname	= "numa_balancing_scan_period_min_ms",
366 		.data		= &sysctl_numa_balancing_scan_period_min,
367 		.maxlen		= sizeof(unsigned int),
368 		.mode		= 0644,
369 		.proc_handler	= proc_dointvec,
370 	},
371 	{
372 		.procname	= "numa_balancing_scan_period_max_ms",
373 		.data		= &sysctl_numa_balancing_scan_period_max,
374 		.maxlen		= sizeof(unsigned int),
375 		.mode		= 0644,
376 		.proc_handler	= proc_dointvec,
377 	},
378 	{
379 		.procname	= "numa_balancing_scan_size_mb",
380 		.data		= &sysctl_numa_balancing_scan_size,
381 		.maxlen		= sizeof(unsigned int),
382 		.mode		= 0644,
383 		.proc_handler	= proc_dointvec,
384 	},
385 	{
386 		.procname	= "numa_balancing",
387 		.data		= NULL, /* filled in by handler */
388 		.maxlen		= sizeof(unsigned int),
389 		.mode		= 0644,
390 		.proc_handler	= sysctl_numa_balancing,
391 		.extra1		= &zero,
392 		.extra2		= &one,
393 	},
394 #endif /* CONFIG_NUMA_BALANCING */
395 #endif /* CONFIG_SCHED_DEBUG */
396 	{
397 		.procname	= "sched_rt_period_us",
398 		.data		= &sysctl_sched_rt_period,
399 		.maxlen		= sizeof(unsigned int),
400 		.mode		= 0644,
401 		.proc_handler	= sched_rt_handler,
402 	},
403 	{
404 		.procname	= "sched_rt_runtime_us",
405 		.data		= &sysctl_sched_rt_runtime,
406 		.maxlen		= sizeof(int),
407 		.mode		= 0644,
408 		.proc_handler	= sched_rt_handler,
409 	},
410 	{
411 		.procname	= "sched_rr_timeslice_ms",
412 		.data		= &sched_rr_timeslice,
413 		.maxlen		= sizeof(int),
414 		.mode		= 0644,
415 		.proc_handler	= sched_rr_handler,
416 	},
417 #ifdef CONFIG_SCHED_AUTOGROUP
418 	{
419 		.procname	= "sched_autogroup_enabled",
420 		.data		= &sysctl_sched_autogroup_enabled,
421 		.maxlen		= sizeof(unsigned int),
422 		.mode		= 0644,
423 		.proc_handler	= proc_dointvec_minmax,
424 		.extra1		= &zero,
425 		.extra2		= &one,
426 	},
427 #endif
428 #ifdef CONFIG_CFS_BANDWIDTH
429 	{
430 		.procname	= "sched_cfs_bandwidth_slice_us",
431 		.data		= &sysctl_sched_cfs_bandwidth_slice,
432 		.maxlen		= sizeof(unsigned int),
433 		.mode		= 0644,
434 		.proc_handler	= proc_dointvec_minmax,
435 		.extra1		= &one,
436 	},
437 #endif
438 #ifdef CONFIG_PROVE_LOCKING
439 	{
440 		.procname	= "prove_locking",
441 		.data		= &prove_locking,
442 		.maxlen		= sizeof(int),
443 		.mode		= 0644,
444 		.proc_handler	= proc_dointvec,
445 	},
446 #endif
447 #ifdef CONFIG_LOCK_STAT
448 	{
449 		.procname	= "lock_stat",
450 		.data		= &lock_stat,
451 		.maxlen		= sizeof(int),
452 		.mode		= 0644,
453 		.proc_handler	= proc_dointvec,
454 	},
455 #endif
456 	{
457 		.procname	= "panic",
458 		.data		= &panic_timeout,
459 		.maxlen		= sizeof(int),
460 		.mode		= 0644,
461 		.proc_handler	= proc_dointvec,
462 	},
463 #ifdef CONFIG_COREDUMP
464 	{
465 		.procname	= "core_uses_pid",
466 		.data		= &core_uses_pid,
467 		.maxlen		= sizeof(int),
468 		.mode		= 0644,
469 		.proc_handler	= proc_dointvec,
470 	},
471 	{
472 		.procname	= "core_pattern",
473 		.data		= core_pattern,
474 		.maxlen		= CORENAME_MAX_SIZE,
475 		.mode		= 0644,
476 		.proc_handler	= proc_dostring_coredump,
477 	},
478 	{
479 		.procname	= "core_pipe_limit",
480 		.data		= &core_pipe_limit,
481 		.maxlen		= sizeof(unsigned int),
482 		.mode		= 0644,
483 		.proc_handler	= proc_dointvec,
484 	},
485 #endif
486 #ifdef CONFIG_PROC_SYSCTL
487 	{
488 		.procname	= "tainted",
489 		.maxlen 	= sizeof(long),
490 		.mode		= 0644,
491 		.proc_handler	= proc_taint,
492 	},
493 #endif
494 #ifdef CONFIG_LATENCYTOP
495 	{
496 		.procname	= "latencytop",
497 		.data		= &latencytop_enabled,
498 		.maxlen		= sizeof(int),
499 		.mode		= 0644,
500 		.proc_handler	= proc_dointvec,
501 	},
502 #endif
503 #ifdef CONFIG_BLK_DEV_INITRD
504 	{
505 		.procname	= "real-root-dev",
506 		.data		= &real_root_dev,
507 		.maxlen		= sizeof(int),
508 		.mode		= 0644,
509 		.proc_handler	= proc_dointvec,
510 	},
511 #endif
512 	{
513 		.procname	= "print-fatal-signals",
514 		.data		= &print_fatal_signals,
515 		.maxlen		= sizeof(int),
516 		.mode		= 0644,
517 		.proc_handler	= proc_dointvec,
518 	},
519 #ifdef CONFIG_SPARC
520 	{
521 		.procname	= "reboot-cmd",
522 		.data		= reboot_command,
523 		.maxlen		= 256,
524 		.mode		= 0644,
525 		.proc_handler	= proc_dostring,
526 	},
527 	{
528 		.procname	= "stop-a",
529 		.data		= &stop_a_enabled,
530 		.maxlen		= sizeof (int),
531 		.mode		= 0644,
532 		.proc_handler	= proc_dointvec,
533 	},
534 	{
535 		.procname	= "scons-poweroff",
536 		.data		= &scons_pwroff,
537 		.maxlen		= sizeof (int),
538 		.mode		= 0644,
539 		.proc_handler	= proc_dointvec,
540 	},
541 #endif
542 #ifdef CONFIG_SPARC64
543 	{
544 		.procname	= "tsb-ratio",
545 		.data		= &sysctl_tsb_ratio,
546 		.maxlen		= sizeof (int),
547 		.mode		= 0644,
548 		.proc_handler	= proc_dointvec,
549 	},
550 #endif
551 #ifdef __hppa__
552 	{
553 		.procname	= "soft-power",
554 		.data		= &pwrsw_enabled,
555 		.maxlen		= sizeof (int),
556 	 	.mode		= 0644,
557 		.proc_handler	= proc_dointvec,
558 	},
559 #endif
560 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
561 	{
562 		.procname	= "unaligned-trap",
563 		.data		= &unaligned_enabled,
564 		.maxlen		= sizeof (int),
565 		.mode		= 0644,
566 		.proc_handler	= proc_dointvec,
567 	},
568 #endif
569 	{
570 		.procname	= "ctrl-alt-del",
571 		.data		= &C_A_D,
572 		.maxlen		= sizeof(int),
573 		.mode		= 0644,
574 		.proc_handler	= proc_dointvec,
575 	},
576 #ifdef CONFIG_FUNCTION_TRACER
577 	{
578 		.procname	= "ftrace_enabled",
579 		.data		= &ftrace_enabled,
580 		.maxlen		= sizeof(int),
581 		.mode		= 0644,
582 		.proc_handler	= ftrace_enable_sysctl,
583 	},
584 #endif
585 #ifdef CONFIG_STACK_TRACER
586 	{
587 		.procname	= "stack_tracer_enabled",
588 		.data		= &stack_tracer_enabled,
589 		.maxlen		= sizeof(int),
590 		.mode		= 0644,
591 		.proc_handler	= stack_trace_sysctl,
592 	},
593 #endif
594 #ifdef CONFIG_TRACING
595 	{
596 		.procname	= "ftrace_dump_on_oops",
597 		.data		= &ftrace_dump_on_oops,
598 		.maxlen		= sizeof(int),
599 		.mode		= 0644,
600 		.proc_handler	= proc_dointvec,
601 	},
602 	{
603 		.procname	= "traceoff_on_warning",
604 		.data		= &__disable_trace_on_warning,
605 		.maxlen		= sizeof(__disable_trace_on_warning),
606 		.mode		= 0644,
607 		.proc_handler	= proc_dointvec,
608 	},
609 #endif
610 #ifdef CONFIG_KEXEC
611 	{
612 		.procname	= "kexec_load_disabled",
613 		.data		= &kexec_load_disabled,
614 		.maxlen		= sizeof(int),
615 		.mode		= 0644,
616 		/* only handle a transition from default "0" to "1" */
617 		.proc_handler	= proc_dointvec_minmax,
618 		.extra1		= &one,
619 		.extra2		= &one,
620 	},
621 #endif
622 #ifdef CONFIG_MODULES
623 	{
624 		.procname	= "modprobe",
625 		.data		= &modprobe_path,
626 		.maxlen		= KMOD_PATH_LEN,
627 		.mode		= 0644,
628 		.proc_handler	= proc_dostring,
629 	},
630 	{
631 		.procname	= "modules_disabled",
632 		.data		= &modules_disabled,
633 		.maxlen		= sizeof(int),
634 		.mode		= 0644,
635 		/* only handle a transition from default "0" to "1" */
636 		.proc_handler	= proc_dointvec_minmax,
637 		.extra1		= &one,
638 		.extra2		= &one,
639 	},
640 #endif
641 
642 	{
643 		.procname	= "hotplug",
644 		.data		= &uevent_helper,
645 		.maxlen		= UEVENT_HELPER_PATH_LEN,
646 		.mode		= 0644,
647 		.proc_handler	= proc_dostring,
648 	},
649 
650 #ifdef CONFIG_CHR_DEV_SG
651 	{
652 		.procname	= "sg-big-buff",
653 		.data		= &sg_big_buff,
654 		.maxlen		= sizeof (int),
655 		.mode		= 0444,
656 		.proc_handler	= proc_dointvec,
657 	},
658 #endif
659 #ifdef CONFIG_BSD_PROCESS_ACCT
660 	{
661 		.procname	= "acct",
662 		.data		= &acct_parm,
663 		.maxlen		= 3*sizeof(int),
664 		.mode		= 0644,
665 		.proc_handler	= proc_dointvec,
666 	},
667 #endif
668 #ifdef CONFIG_MAGIC_SYSRQ
669 	{
670 		.procname	= "sysrq",
671 		.data		= &__sysrq_enabled,
672 		.maxlen		= sizeof (int),
673 		.mode		= 0644,
674 		.proc_handler	= sysrq_sysctl_handler,
675 	},
676 #endif
677 #ifdef CONFIG_PROC_SYSCTL
678 	{
679 		.procname	= "cad_pid",
680 		.data		= NULL,
681 		.maxlen		= sizeof (int),
682 		.mode		= 0600,
683 		.proc_handler	= proc_do_cad_pid,
684 	},
685 #endif
686 	{
687 		.procname	= "threads-max",
688 		.data		= &max_threads,
689 		.maxlen		= sizeof(int),
690 		.mode		= 0644,
691 		.proc_handler	= proc_dointvec,
692 	},
693 	{
694 		.procname	= "random",
695 		.mode		= 0555,
696 		.child		= random_table,
697 	},
698 	{
699 		.procname	= "usermodehelper",
700 		.mode		= 0555,
701 		.child		= usermodehelper_table,
702 	},
703 	{
704 		.procname	= "overflowuid",
705 		.data		= &overflowuid,
706 		.maxlen		= sizeof(int),
707 		.mode		= 0644,
708 		.proc_handler	= proc_dointvec_minmax,
709 		.extra1		= &minolduid,
710 		.extra2		= &maxolduid,
711 	},
712 	{
713 		.procname	= "overflowgid",
714 		.data		= &overflowgid,
715 		.maxlen		= sizeof(int),
716 		.mode		= 0644,
717 		.proc_handler	= proc_dointvec_minmax,
718 		.extra1		= &minolduid,
719 		.extra2		= &maxolduid,
720 	},
721 #ifdef CONFIG_S390
722 #ifdef CONFIG_MATHEMU
723 	{
724 		.procname	= "ieee_emulation_warnings",
725 		.data		= &sysctl_ieee_emulation_warnings,
726 		.maxlen		= sizeof(int),
727 		.mode		= 0644,
728 		.proc_handler	= proc_dointvec,
729 	},
730 #endif
731 	{
732 		.procname	= "userprocess_debug",
733 		.data		= &show_unhandled_signals,
734 		.maxlen		= sizeof(int),
735 		.mode		= 0644,
736 		.proc_handler	= proc_dointvec,
737 	},
738 #endif
739 	{
740 		.procname	= "pid_max",
741 		.data		= &pid_max,
742 		.maxlen		= sizeof (int),
743 		.mode		= 0644,
744 		.proc_handler	= proc_dointvec_minmax,
745 		.extra1		= &pid_max_min,
746 		.extra2		= &pid_max_max,
747 	},
748 	{
749 		.procname	= "panic_on_oops",
750 		.data		= &panic_on_oops,
751 		.maxlen		= sizeof(int),
752 		.mode		= 0644,
753 		.proc_handler	= proc_dointvec,
754 	},
755 #if defined CONFIG_PRINTK
756 	{
757 		.procname	= "printk",
758 		.data		= &console_loglevel,
759 		.maxlen		= 4*sizeof(int),
760 		.mode		= 0644,
761 		.proc_handler	= proc_dointvec,
762 	},
763 	{
764 		.procname	= "printk_ratelimit",
765 		.data		= &printk_ratelimit_state.interval,
766 		.maxlen		= sizeof(int),
767 		.mode		= 0644,
768 		.proc_handler	= proc_dointvec_jiffies,
769 	},
770 	{
771 		.procname	= "printk_ratelimit_burst",
772 		.data		= &printk_ratelimit_state.burst,
773 		.maxlen		= sizeof(int),
774 		.mode		= 0644,
775 		.proc_handler	= proc_dointvec,
776 	},
777 	{
778 		.procname	= "printk_delay",
779 		.data		= &printk_delay_msec,
780 		.maxlen		= sizeof(int),
781 		.mode		= 0644,
782 		.proc_handler	= proc_dointvec_minmax,
783 		.extra1		= &zero,
784 		.extra2		= &ten_thousand,
785 	},
786 	{
787 		.procname	= "dmesg_restrict",
788 		.data		= &dmesg_restrict,
789 		.maxlen		= sizeof(int),
790 		.mode		= 0644,
791 		.proc_handler	= proc_dointvec_minmax_sysadmin,
792 		.extra1		= &zero,
793 		.extra2		= &one,
794 	},
795 	{
796 		.procname	= "kptr_restrict",
797 		.data		= &kptr_restrict,
798 		.maxlen		= sizeof(int),
799 		.mode		= 0644,
800 		.proc_handler	= proc_dointvec_minmax_sysadmin,
801 		.extra1		= &zero,
802 		.extra2		= &two,
803 	},
804 #endif
805 	{
806 		.procname	= "ngroups_max",
807 		.data		= &ngroups_max,
808 		.maxlen		= sizeof (int),
809 		.mode		= 0444,
810 		.proc_handler	= proc_dointvec,
811 	},
812 	{
813 		.procname	= "cap_last_cap",
814 		.data		= (void *)&cap_last_cap,
815 		.maxlen		= sizeof(int),
816 		.mode		= 0444,
817 		.proc_handler	= proc_dointvec,
818 	},
819 #if defined(CONFIG_LOCKUP_DETECTOR)
820 	{
821 		.procname       = "watchdog",
822 		.data           = &watchdog_user_enabled,
823 		.maxlen         = sizeof (int),
824 		.mode           = 0644,
825 		.proc_handler   = proc_dowatchdog,
826 		.extra1		= &zero,
827 		.extra2		= &one,
828 	},
829 	{
830 		.procname	= "watchdog_thresh",
831 		.data		= &watchdog_thresh,
832 		.maxlen		= sizeof(int),
833 		.mode		= 0644,
834 		.proc_handler	= proc_dowatchdog,
835 		.extra1		= &zero,
836 		.extra2		= &sixty,
837 	},
838 	{
839 		.procname	= "softlockup_panic",
840 		.data		= &softlockup_panic,
841 		.maxlen		= sizeof(int),
842 		.mode		= 0644,
843 		.proc_handler	= proc_dointvec_minmax,
844 		.extra1		= &zero,
845 		.extra2		= &one,
846 	},
847 	{
848 		.procname       = "nmi_watchdog",
849 		.data           = &watchdog_user_enabled,
850 		.maxlen         = sizeof (int),
851 		.mode           = 0644,
852 		.proc_handler   = proc_dowatchdog,
853 		.extra1		= &zero,
854 		.extra2		= &one,
855 	},
856 #endif
857 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
858 	{
859 		.procname       = "unknown_nmi_panic",
860 		.data           = &unknown_nmi_panic,
861 		.maxlen         = sizeof (int),
862 		.mode           = 0644,
863 		.proc_handler   = proc_dointvec,
864 	},
865 #endif
866 #if defined(CONFIG_X86)
867 	{
868 		.procname	= "panic_on_unrecovered_nmi",
869 		.data		= &panic_on_unrecovered_nmi,
870 		.maxlen		= sizeof(int),
871 		.mode		= 0644,
872 		.proc_handler	= proc_dointvec,
873 	},
874 	{
875 		.procname	= "panic_on_io_nmi",
876 		.data		= &panic_on_io_nmi,
877 		.maxlen		= sizeof(int),
878 		.mode		= 0644,
879 		.proc_handler	= proc_dointvec,
880 	},
881 #ifdef CONFIG_DEBUG_STACKOVERFLOW
882 	{
883 		.procname	= "panic_on_stackoverflow",
884 		.data		= &sysctl_panic_on_stackoverflow,
885 		.maxlen		= sizeof(int),
886 		.mode		= 0644,
887 		.proc_handler	= proc_dointvec,
888 	},
889 #endif
890 	{
891 		.procname	= "bootloader_type",
892 		.data		= &bootloader_type,
893 		.maxlen		= sizeof (int),
894 		.mode		= 0444,
895 		.proc_handler	= proc_dointvec,
896 	},
897 	{
898 		.procname	= "bootloader_version",
899 		.data		= &bootloader_version,
900 		.maxlen		= sizeof (int),
901 		.mode		= 0444,
902 		.proc_handler	= proc_dointvec,
903 	},
904 	{
905 		.procname	= "kstack_depth_to_print",
906 		.data		= &kstack_depth_to_print,
907 		.maxlen		= sizeof(int),
908 		.mode		= 0644,
909 		.proc_handler	= proc_dointvec,
910 	},
911 	{
912 		.procname	= "io_delay_type",
913 		.data		= &io_delay_type,
914 		.maxlen		= sizeof(int),
915 		.mode		= 0644,
916 		.proc_handler	= proc_dointvec,
917 	},
918 #endif
919 #if defined(CONFIG_MMU)
920 	{
921 		.procname	= "randomize_va_space",
922 		.data		= &randomize_va_space,
923 		.maxlen		= sizeof(int),
924 		.mode		= 0644,
925 		.proc_handler	= proc_dointvec,
926 	},
927 #endif
928 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
929 	{
930 		.procname	= "spin_retry",
931 		.data		= &spin_retry,
932 		.maxlen		= sizeof (int),
933 		.mode		= 0644,
934 		.proc_handler	= proc_dointvec,
935 	},
936 #endif
937 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
938 	{
939 		.procname	= "acpi_video_flags",
940 		.data		= &acpi_realmode_flags,
941 		.maxlen		= sizeof (unsigned long),
942 		.mode		= 0644,
943 		.proc_handler	= proc_doulongvec_minmax,
944 	},
945 #endif
946 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
947 	{
948 		.procname	= "ignore-unaligned-usertrap",
949 		.data		= &no_unaligned_warning,
950 		.maxlen		= sizeof (int),
951 	 	.mode		= 0644,
952 		.proc_handler	= proc_dointvec,
953 	},
954 #endif
955 #ifdef CONFIG_IA64
956 	{
957 		.procname	= "unaligned-dump-stack",
958 		.data		= &unaligned_dump_stack,
959 		.maxlen		= sizeof (int),
960 		.mode		= 0644,
961 		.proc_handler	= proc_dointvec,
962 	},
963 #endif
964 #ifdef CONFIG_DETECT_HUNG_TASK
965 	{
966 		.procname	= "hung_task_panic",
967 		.data		= &sysctl_hung_task_panic,
968 		.maxlen		= sizeof(int),
969 		.mode		= 0644,
970 		.proc_handler	= proc_dointvec_minmax,
971 		.extra1		= &zero,
972 		.extra2		= &one,
973 	},
974 	{
975 		.procname	= "hung_task_check_count",
976 		.data		= &sysctl_hung_task_check_count,
977 		.maxlen		= sizeof(int),
978 		.mode		= 0644,
979 		.proc_handler	= proc_dointvec_minmax,
980 		.extra1		= &zero,
981 	},
982 	{
983 		.procname	= "hung_task_timeout_secs",
984 		.data		= &sysctl_hung_task_timeout_secs,
985 		.maxlen		= sizeof(unsigned long),
986 		.mode		= 0644,
987 		.proc_handler	= proc_dohung_task_timeout_secs,
988 	},
989 	{
990 		.procname	= "hung_task_warnings",
991 		.data		= &sysctl_hung_task_warnings,
992 		.maxlen		= sizeof(int),
993 		.mode		= 0644,
994 		.proc_handler	= proc_dointvec_minmax,
995 		.extra1		= &neg_one,
996 	},
997 #endif
998 #ifdef CONFIG_COMPAT
999 	{
1000 		.procname	= "compat-log",
1001 		.data		= &compat_log,
1002 		.maxlen		= sizeof (int),
1003 	 	.mode		= 0644,
1004 		.proc_handler	= proc_dointvec,
1005 	},
1006 #endif
1007 #ifdef CONFIG_RT_MUTEXES
1008 	{
1009 		.procname	= "max_lock_depth",
1010 		.data		= &max_lock_depth,
1011 		.maxlen		= sizeof(int),
1012 		.mode		= 0644,
1013 		.proc_handler	= proc_dointvec,
1014 	},
1015 #endif
1016 	{
1017 		.procname	= "poweroff_cmd",
1018 		.data		= &poweroff_cmd,
1019 		.maxlen		= POWEROFF_CMD_PATH_LEN,
1020 		.mode		= 0644,
1021 		.proc_handler	= proc_dostring,
1022 	},
1023 #ifdef CONFIG_KEYS
1024 	{
1025 		.procname	= "keys",
1026 		.mode		= 0555,
1027 		.child		= key_sysctls,
1028 	},
1029 #endif
1030 #ifdef CONFIG_RCU_TORTURE_TEST
1031 	{
1032 		.procname       = "rcutorture_runnable",
1033 		.data           = &rcutorture_runnable,
1034 		.maxlen         = sizeof(int),
1035 		.mode           = 0644,
1036 		.proc_handler	= proc_dointvec,
1037 	},
1038 #endif
1039 #ifdef CONFIG_PERF_EVENTS
1040 	/*
1041 	 * User-space scripts rely on the existence of this file
1042 	 * as a feature check for perf_events being enabled.
1043 	 *
1044 	 * So it's an ABI, do not remove!
1045 	 */
1046 	{
1047 		.procname	= "perf_event_paranoid",
1048 		.data		= &sysctl_perf_event_paranoid,
1049 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
1050 		.mode		= 0644,
1051 		.proc_handler	= proc_dointvec,
1052 	},
1053 	{
1054 		.procname	= "perf_event_mlock_kb",
1055 		.data		= &sysctl_perf_event_mlock,
1056 		.maxlen		= sizeof(sysctl_perf_event_mlock),
1057 		.mode		= 0644,
1058 		.proc_handler	= proc_dointvec,
1059 	},
1060 	{
1061 		.procname	= "perf_event_max_sample_rate",
1062 		.data		= &sysctl_perf_event_sample_rate,
1063 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
1064 		.mode		= 0644,
1065 		.proc_handler	= perf_proc_update_handler,
1066 		.extra1		= &one,
1067 	},
1068 	{
1069 		.procname	= "perf_cpu_time_max_percent",
1070 		.data		= &sysctl_perf_cpu_time_max_percent,
1071 		.maxlen		= sizeof(sysctl_perf_cpu_time_max_percent),
1072 		.mode		= 0644,
1073 		.proc_handler	= perf_cpu_time_max_percent_handler,
1074 		.extra1		= &zero,
1075 		.extra2		= &one_hundred,
1076 	},
1077 #endif
1078 #ifdef CONFIG_KMEMCHECK
1079 	{
1080 		.procname	= "kmemcheck",
1081 		.data		= &kmemcheck_enabled,
1082 		.maxlen		= sizeof(int),
1083 		.mode		= 0644,
1084 		.proc_handler	= proc_dointvec,
1085 	},
1086 #endif
1087 	{ }
1088 };
1089 
1090 static struct ctl_table vm_table[] = {
1091 	{
1092 		.procname	= "overcommit_memory",
1093 		.data		= &sysctl_overcommit_memory,
1094 		.maxlen		= sizeof(sysctl_overcommit_memory),
1095 		.mode		= 0644,
1096 		.proc_handler	= proc_dointvec_minmax,
1097 		.extra1		= &zero,
1098 		.extra2		= &two,
1099 	},
1100 	{
1101 		.procname	= "panic_on_oom",
1102 		.data		= &sysctl_panic_on_oom,
1103 		.maxlen		= sizeof(sysctl_panic_on_oom),
1104 		.mode		= 0644,
1105 		.proc_handler	= proc_dointvec_minmax,
1106 		.extra1		= &zero,
1107 		.extra2		= &two,
1108 	},
1109 	{
1110 		.procname	= "oom_kill_allocating_task",
1111 		.data		= &sysctl_oom_kill_allocating_task,
1112 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1113 		.mode		= 0644,
1114 		.proc_handler	= proc_dointvec,
1115 	},
1116 	{
1117 		.procname	= "oom_dump_tasks",
1118 		.data		= &sysctl_oom_dump_tasks,
1119 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1120 		.mode		= 0644,
1121 		.proc_handler	= proc_dointvec,
1122 	},
1123 	{
1124 		.procname	= "overcommit_ratio",
1125 		.data		= &sysctl_overcommit_ratio,
1126 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1127 		.mode		= 0644,
1128 		.proc_handler	= overcommit_ratio_handler,
1129 	},
1130 	{
1131 		.procname	= "overcommit_kbytes",
1132 		.data		= &sysctl_overcommit_kbytes,
1133 		.maxlen		= sizeof(sysctl_overcommit_kbytes),
1134 		.mode		= 0644,
1135 		.proc_handler	= overcommit_kbytes_handler,
1136 	},
1137 	{
1138 		.procname	= "page-cluster",
1139 		.data		= &page_cluster,
1140 		.maxlen		= sizeof(int),
1141 		.mode		= 0644,
1142 		.proc_handler	= proc_dointvec_minmax,
1143 		.extra1		= &zero,
1144 	},
1145 	{
1146 		.procname	= "dirty_background_ratio",
1147 		.data		= &dirty_background_ratio,
1148 		.maxlen		= sizeof(dirty_background_ratio),
1149 		.mode		= 0644,
1150 		.proc_handler	= dirty_background_ratio_handler,
1151 		.extra1		= &zero,
1152 		.extra2		= &one_hundred,
1153 	},
1154 	{
1155 		.procname	= "dirty_background_bytes",
1156 		.data		= &dirty_background_bytes,
1157 		.maxlen		= sizeof(dirty_background_bytes),
1158 		.mode		= 0644,
1159 		.proc_handler	= dirty_background_bytes_handler,
1160 		.extra1		= &one_ul,
1161 	},
1162 	{
1163 		.procname	= "dirty_ratio",
1164 		.data		= &vm_dirty_ratio,
1165 		.maxlen		= sizeof(vm_dirty_ratio),
1166 		.mode		= 0644,
1167 		.proc_handler	= dirty_ratio_handler,
1168 		.extra1		= &zero,
1169 		.extra2		= &one_hundred,
1170 	},
1171 	{
1172 		.procname	= "dirty_bytes",
1173 		.data		= &vm_dirty_bytes,
1174 		.maxlen		= sizeof(vm_dirty_bytes),
1175 		.mode		= 0644,
1176 		.proc_handler	= dirty_bytes_handler,
1177 		.extra1		= &dirty_bytes_min,
1178 	},
1179 	{
1180 		.procname	= "dirty_writeback_centisecs",
1181 		.data		= &dirty_writeback_interval,
1182 		.maxlen		= sizeof(dirty_writeback_interval),
1183 		.mode		= 0644,
1184 		.proc_handler	= dirty_writeback_centisecs_handler,
1185 	},
1186 	{
1187 		.procname	= "dirty_expire_centisecs",
1188 		.data		= &dirty_expire_interval,
1189 		.maxlen		= sizeof(dirty_expire_interval),
1190 		.mode		= 0644,
1191 		.proc_handler	= proc_dointvec_minmax,
1192 		.extra1		= &zero,
1193 	},
1194 	{
1195 		.procname       = "nr_pdflush_threads",
1196 		.mode           = 0444 /* read-only */,
1197 		.proc_handler   = pdflush_proc_obsolete,
1198 	},
1199 	{
1200 		.procname	= "swappiness",
1201 		.data		= &vm_swappiness,
1202 		.maxlen		= sizeof(vm_swappiness),
1203 		.mode		= 0644,
1204 		.proc_handler	= proc_dointvec_minmax,
1205 		.extra1		= &zero,
1206 		.extra2		= &one_hundred,
1207 	},
1208 #ifdef CONFIG_HUGETLB_PAGE
1209 	{
1210 		.procname	= "nr_hugepages",
1211 		.data		= NULL,
1212 		.maxlen		= sizeof(unsigned long),
1213 		.mode		= 0644,
1214 		.proc_handler	= hugetlb_sysctl_handler,
1215 		.extra1		= (void *)&hugetlb_zero,
1216 		.extra2		= (void *)&hugetlb_infinity,
1217 	},
1218 #ifdef CONFIG_NUMA
1219 	{
1220 		.procname       = "nr_hugepages_mempolicy",
1221 		.data           = NULL,
1222 		.maxlen         = sizeof(unsigned long),
1223 		.mode           = 0644,
1224 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1225 		.extra1		= (void *)&hugetlb_zero,
1226 		.extra2		= (void *)&hugetlb_infinity,
1227 	},
1228 #endif
1229 	 {
1230 		.procname	= "hugetlb_shm_group",
1231 		.data		= &sysctl_hugetlb_shm_group,
1232 		.maxlen		= sizeof(gid_t),
1233 		.mode		= 0644,
1234 		.proc_handler	= proc_dointvec,
1235 	 },
1236 	 {
1237 		.procname	= "hugepages_treat_as_movable",
1238 		.data		= &hugepages_treat_as_movable,
1239 		.maxlen		= sizeof(int),
1240 		.mode		= 0644,
1241 		.proc_handler	= proc_dointvec,
1242 	},
1243 	{
1244 		.procname	= "nr_overcommit_hugepages",
1245 		.data		= NULL,
1246 		.maxlen		= sizeof(unsigned long),
1247 		.mode		= 0644,
1248 		.proc_handler	= hugetlb_overcommit_handler,
1249 		.extra1		= (void *)&hugetlb_zero,
1250 		.extra2		= (void *)&hugetlb_infinity,
1251 	},
1252 #endif
1253 	{
1254 		.procname	= "lowmem_reserve_ratio",
1255 		.data		= &sysctl_lowmem_reserve_ratio,
1256 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1257 		.mode		= 0644,
1258 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1259 	},
1260 	{
1261 		.procname	= "drop_caches",
1262 		.data		= &sysctl_drop_caches,
1263 		.maxlen		= sizeof(int),
1264 		.mode		= 0644,
1265 		.proc_handler	= drop_caches_sysctl_handler,
1266 		.extra1		= &one,
1267 		.extra2		= &four,
1268 	},
1269 #ifdef CONFIG_COMPACTION
1270 	{
1271 		.procname	= "compact_memory",
1272 		.data		= &sysctl_compact_memory,
1273 		.maxlen		= sizeof(int),
1274 		.mode		= 0200,
1275 		.proc_handler	= sysctl_compaction_handler,
1276 	},
1277 	{
1278 		.procname	= "extfrag_threshold",
1279 		.data		= &sysctl_extfrag_threshold,
1280 		.maxlen		= sizeof(int),
1281 		.mode		= 0644,
1282 		.proc_handler	= sysctl_extfrag_handler,
1283 		.extra1		= &min_extfrag_threshold,
1284 		.extra2		= &max_extfrag_threshold,
1285 	},
1286 
1287 #endif /* CONFIG_COMPACTION */
1288 	{
1289 		.procname	= "min_free_kbytes",
1290 		.data		= &min_free_kbytes,
1291 		.maxlen		= sizeof(min_free_kbytes),
1292 		.mode		= 0644,
1293 		.proc_handler	= min_free_kbytes_sysctl_handler,
1294 		.extra1		= &zero,
1295 	},
1296 	{
1297 		.procname	= "percpu_pagelist_fraction",
1298 		.data		= &percpu_pagelist_fraction,
1299 		.maxlen		= sizeof(percpu_pagelist_fraction),
1300 		.mode		= 0644,
1301 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1302 		.extra1		= &min_percpu_pagelist_fract,
1303 	},
1304 #ifdef CONFIG_MMU
1305 	{
1306 		.procname	= "max_map_count",
1307 		.data		= &sysctl_max_map_count,
1308 		.maxlen		= sizeof(sysctl_max_map_count),
1309 		.mode		= 0644,
1310 		.proc_handler	= proc_dointvec_minmax,
1311 		.extra1		= &zero,
1312 	},
1313 #else
1314 	{
1315 		.procname	= "nr_trim_pages",
1316 		.data		= &sysctl_nr_trim_pages,
1317 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1318 		.mode		= 0644,
1319 		.proc_handler	= proc_dointvec_minmax,
1320 		.extra1		= &zero,
1321 	},
1322 #endif
1323 	{
1324 		.procname	= "laptop_mode",
1325 		.data		= &laptop_mode,
1326 		.maxlen		= sizeof(laptop_mode),
1327 		.mode		= 0644,
1328 		.proc_handler	= proc_dointvec_jiffies,
1329 	},
1330 	{
1331 		.procname	= "block_dump",
1332 		.data		= &block_dump,
1333 		.maxlen		= sizeof(block_dump),
1334 		.mode		= 0644,
1335 		.proc_handler	= proc_dointvec,
1336 		.extra1		= &zero,
1337 	},
1338 	{
1339 		.procname	= "vfs_cache_pressure",
1340 		.data		= &sysctl_vfs_cache_pressure,
1341 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1342 		.mode		= 0644,
1343 		.proc_handler	= proc_dointvec,
1344 		.extra1		= &zero,
1345 	},
1346 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1347 	{
1348 		.procname	= "legacy_va_layout",
1349 		.data		= &sysctl_legacy_va_layout,
1350 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1351 		.mode		= 0644,
1352 		.proc_handler	= proc_dointvec,
1353 		.extra1		= &zero,
1354 	},
1355 #endif
1356 #ifdef CONFIG_NUMA
1357 	{
1358 		.procname	= "zone_reclaim_mode",
1359 		.data		= &zone_reclaim_mode,
1360 		.maxlen		= sizeof(zone_reclaim_mode),
1361 		.mode		= 0644,
1362 		.proc_handler	= proc_dointvec,
1363 		.extra1		= &zero,
1364 	},
1365 	{
1366 		.procname	= "min_unmapped_ratio",
1367 		.data		= &sysctl_min_unmapped_ratio,
1368 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1369 		.mode		= 0644,
1370 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1371 		.extra1		= &zero,
1372 		.extra2		= &one_hundred,
1373 	},
1374 	{
1375 		.procname	= "min_slab_ratio",
1376 		.data		= &sysctl_min_slab_ratio,
1377 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1378 		.mode		= 0644,
1379 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1380 		.extra1		= &zero,
1381 		.extra2		= &one_hundred,
1382 	},
1383 #endif
1384 #ifdef CONFIG_SMP
1385 	{
1386 		.procname	= "stat_interval",
1387 		.data		= &sysctl_stat_interval,
1388 		.maxlen		= sizeof(sysctl_stat_interval),
1389 		.mode		= 0644,
1390 		.proc_handler	= proc_dointvec_jiffies,
1391 	},
1392 #endif
1393 #ifdef CONFIG_MMU
1394 	{
1395 		.procname	= "mmap_min_addr",
1396 		.data		= &dac_mmap_min_addr,
1397 		.maxlen		= sizeof(unsigned long),
1398 		.mode		= 0644,
1399 		.proc_handler	= mmap_min_addr_handler,
1400 	},
1401 #endif
1402 #ifdef CONFIG_NUMA
1403 	{
1404 		.procname	= "numa_zonelist_order",
1405 		.data		= &numa_zonelist_order,
1406 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1407 		.mode		= 0644,
1408 		.proc_handler	= numa_zonelist_order_handler,
1409 	},
1410 #endif
1411 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1412    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1413 	{
1414 		.procname	= "vdso_enabled",
1415 		.data		= &vdso_enabled,
1416 		.maxlen		= sizeof(vdso_enabled),
1417 		.mode		= 0644,
1418 		.proc_handler	= proc_dointvec,
1419 		.extra1		= &zero,
1420 	},
1421 #endif
1422 #ifdef CONFIG_HIGHMEM
1423 	{
1424 		.procname	= "highmem_is_dirtyable",
1425 		.data		= &vm_highmem_is_dirtyable,
1426 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1427 		.mode		= 0644,
1428 		.proc_handler	= proc_dointvec_minmax,
1429 		.extra1		= &zero,
1430 		.extra2		= &one,
1431 	},
1432 #endif
1433 	{
1434 		.procname	= "scan_unevictable_pages",
1435 		.data		= &scan_unevictable_pages,
1436 		.maxlen		= sizeof(scan_unevictable_pages),
1437 		.mode		= 0644,
1438 		.proc_handler	= scan_unevictable_handler,
1439 	},
1440 #ifdef CONFIG_MEMORY_FAILURE
1441 	{
1442 		.procname	= "memory_failure_early_kill",
1443 		.data		= &sysctl_memory_failure_early_kill,
1444 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1445 		.mode		= 0644,
1446 		.proc_handler	= proc_dointvec_minmax,
1447 		.extra1		= &zero,
1448 		.extra2		= &one,
1449 	},
1450 	{
1451 		.procname	= "memory_failure_recovery",
1452 		.data		= &sysctl_memory_failure_recovery,
1453 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1454 		.mode		= 0644,
1455 		.proc_handler	= proc_dointvec_minmax,
1456 		.extra1		= &zero,
1457 		.extra2		= &one,
1458 	},
1459 #endif
1460 	{
1461 		.procname	= "user_reserve_kbytes",
1462 		.data		= &sysctl_user_reserve_kbytes,
1463 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1464 		.mode		= 0644,
1465 		.proc_handler	= proc_doulongvec_minmax,
1466 	},
1467 	{
1468 		.procname	= "admin_reserve_kbytes",
1469 		.data		= &sysctl_admin_reserve_kbytes,
1470 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1471 		.mode		= 0644,
1472 		.proc_handler	= proc_doulongvec_minmax,
1473 	},
1474 	{ }
1475 };
1476 
1477 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1478 static struct ctl_table binfmt_misc_table[] = {
1479 	{ }
1480 };
1481 #endif
1482 
1483 static struct ctl_table fs_table[] = {
1484 	{
1485 		.procname	= "inode-nr",
1486 		.data		= &inodes_stat,
1487 		.maxlen		= 2*sizeof(long),
1488 		.mode		= 0444,
1489 		.proc_handler	= proc_nr_inodes,
1490 	},
1491 	{
1492 		.procname	= "inode-state",
1493 		.data		= &inodes_stat,
1494 		.maxlen		= 7*sizeof(long),
1495 		.mode		= 0444,
1496 		.proc_handler	= proc_nr_inodes,
1497 	},
1498 	{
1499 		.procname	= "file-nr",
1500 		.data		= &files_stat,
1501 		.maxlen		= sizeof(files_stat),
1502 		.mode		= 0444,
1503 		.proc_handler	= proc_nr_files,
1504 	},
1505 	{
1506 		.procname	= "file-max",
1507 		.data		= &files_stat.max_files,
1508 		.maxlen		= sizeof(files_stat.max_files),
1509 		.mode		= 0644,
1510 		.proc_handler	= proc_doulongvec_minmax,
1511 	},
1512 	{
1513 		.procname	= "nr_open",
1514 		.data		= &sysctl_nr_open,
1515 		.maxlen		= sizeof(int),
1516 		.mode		= 0644,
1517 		.proc_handler	= proc_dointvec_minmax,
1518 		.extra1		= &sysctl_nr_open_min,
1519 		.extra2		= &sysctl_nr_open_max,
1520 	},
1521 	{
1522 		.procname	= "dentry-state",
1523 		.data		= &dentry_stat,
1524 		.maxlen		= 6*sizeof(long),
1525 		.mode		= 0444,
1526 		.proc_handler	= proc_nr_dentry,
1527 	},
1528 	{
1529 		.procname	= "overflowuid",
1530 		.data		= &fs_overflowuid,
1531 		.maxlen		= sizeof(int),
1532 		.mode		= 0644,
1533 		.proc_handler	= proc_dointvec_minmax,
1534 		.extra1		= &minolduid,
1535 		.extra2		= &maxolduid,
1536 	},
1537 	{
1538 		.procname	= "overflowgid",
1539 		.data		= &fs_overflowgid,
1540 		.maxlen		= sizeof(int),
1541 		.mode		= 0644,
1542 		.proc_handler	= proc_dointvec_minmax,
1543 		.extra1		= &minolduid,
1544 		.extra2		= &maxolduid,
1545 	},
1546 #ifdef CONFIG_FILE_LOCKING
1547 	{
1548 		.procname	= "leases-enable",
1549 		.data		= &leases_enable,
1550 		.maxlen		= sizeof(int),
1551 		.mode		= 0644,
1552 		.proc_handler	= proc_dointvec,
1553 	},
1554 #endif
1555 #ifdef CONFIG_DNOTIFY
1556 	{
1557 		.procname	= "dir-notify-enable",
1558 		.data		= &dir_notify_enable,
1559 		.maxlen		= sizeof(int),
1560 		.mode		= 0644,
1561 		.proc_handler	= proc_dointvec,
1562 	},
1563 #endif
1564 #ifdef CONFIG_MMU
1565 #ifdef CONFIG_FILE_LOCKING
1566 	{
1567 		.procname	= "lease-break-time",
1568 		.data		= &lease_break_time,
1569 		.maxlen		= sizeof(int),
1570 		.mode		= 0644,
1571 		.proc_handler	= proc_dointvec,
1572 	},
1573 #endif
1574 #ifdef CONFIG_AIO
1575 	{
1576 		.procname	= "aio-nr",
1577 		.data		= &aio_nr,
1578 		.maxlen		= sizeof(aio_nr),
1579 		.mode		= 0444,
1580 		.proc_handler	= proc_doulongvec_minmax,
1581 	},
1582 	{
1583 		.procname	= "aio-max-nr",
1584 		.data		= &aio_max_nr,
1585 		.maxlen		= sizeof(aio_max_nr),
1586 		.mode		= 0644,
1587 		.proc_handler	= proc_doulongvec_minmax,
1588 	},
1589 #endif /* CONFIG_AIO */
1590 #ifdef CONFIG_INOTIFY_USER
1591 	{
1592 		.procname	= "inotify",
1593 		.mode		= 0555,
1594 		.child		= inotify_table,
1595 	},
1596 #endif
1597 #ifdef CONFIG_EPOLL
1598 	{
1599 		.procname	= "epoll",
1600 		.mode		= 0555,
1601 		.child		= epoll_table,
1602 	},
1603 #endif
1604 #endif
1605 	{
1606 		.procname	= "protected_symlinks",
1607 		.data		= &sysctl_protected_symlinks,
1608 		.maxlen		= sizeof(int),
1609 		.mode		= 0600,
1610 		.proc_handler	= proc_dointvec_minmax,
1611 		.extra1		= &zero,
1612 		.extra2		= &one,
1613 	},
1614 	{
1615 		.procname	= "protected_hardlinks",
1616 		.data		= &sysctl_protected_hardlinks,
1617 		.maxlen		= sizeof(int),
1618 		.mode		= 0600,
1619 		.proc_handler	= proc_dointvec_minmax,
1620 		.extra1		= &zero,
1621 		.extra2		= &one,
1622 	},
1623 	{
1624 		.procname	= "suid_dumpable",
1625 		.data		= &suid_dumpable,
1626 		.maxlen		= sizeof(int),
1627 		.mode		= 0644,
1628 		.proc_handler	= proc_dointvec_minmax_coredump,
1629 		.extra1		= &zero,
1630 		.extra2		= &two,
1631 	},
1632 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1633 	{
1634 		.procname	= "binfmt_misc",
1635 		.mode		= 0555,
1636 		.child		= binfmt_misc_table,
1637 	},
1638 #endif
1639 	{
1640 		.procname	= "pipe-max-size",
1641 		.data		= &pipe_max_size,
1642 		.maxlen		= sizeof(int),
1643 		.mode		= 0644,
1644 		.proc_handler	= &pipe_proc_fn,
1645 		.extra1		= &pipe_min_size,
1646 	},
1647 	{ }
1648 };
1649 
1650 static struct ctl_table debug_table[] = {
1651 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1652 	{
1653 		.procname	= "exception-trace",
1654 		.data		= &show_unhandled_signals,
1655 		.maxlen		= sizeof(int),
1656 		.mode		= 0644,
1657 		.proc_handler	= proc_dointvec
1658 	},
1659 #endif
1660 #if defined(CONFIG_OPTPROBES)
1661 	{
1662 		.procname	= "kprobes-optimization",
1663 		.data		= &sysctl_kprobes_optimization,
1664 		.maxlen		= sizeof(int),
1665 		.mode		= 0644,
1666 		.proc_handler	= proc_kprobes_optimization_handler,
1667 		.extra1		= &zero,
1668 		.extra2		= &one,
1669 	},
1670 #endif
1671 	{ }
1672 };
1673 
1674 static struct ctl_table dev_table[] = {
1675 	{ }
1676 };
1677 
1678 int __init sysctl_init(void)
1679 {
1680 	struct ctl_table_header *hdr;
1681 
1682 	hdr = register_sysctl_table(sysctl_base_table);
1683 	kmemleak_not_leak(hdr);
1684 	return 0;
1685 }
1686 
1687 #endif /* CONFIG_SYSCTL */
1688 
1689 /*
1690  * /proc/sys support
1691  */
1692 
1693 #ifdef CONFIG_PROC_SYSCTL
1694 
1695 static int _proc_do_string(void* data, int maxlen, int write,
1696 			   void __user *buffer,
1697 			   size_t *lenp, loff_t *ppos)
1698 {
1699 	size_t len;
1700 	char __user *p;
1701 	char c;
1702 
1703 	if (!data || !maxlen || !*lenp) {
1704 		*lenp = 0;
1705 		return 0;
1706 	}
1707 
1708 	if (write) {
1709 		len = 0;
1710 		p = buffer;
1711 		while (len < *lenp) {
1712 			if (get_user(c, p++))
1713 				return -EFAULT;
1714 			if (c == 0 || c == '\n')
1715 				break;
1716 			len++;
1717 		}
1718 		if (len >= maxlen)
1719 			len = maxlen-1;
1720 		if(copy_from_user(data, buffer, len))
1721 			return -EFAULT;
1722 		((char *) data)[len] = 0;
1723 		*ppos += *lenp;
1724 	} else {
1725 		len = strlen(data);
1726 		if (len > maxlen)
1727 			len = maxlen;
1728 
1729 		if (*ppos > len) {
1730 			*lenp = 0;
1731 			return 0;
1732 		}
1733 
1734 		data += *ppos;
1735 		len  -= *ppos;
1736 
1737 		if (len > *lenp)
1738 			len = *lenp;
1739 		if (len)
1740 			if(copy_to_user(buffer, data, len))
1741 				return -EFAULT;
1742 		if (len < *lenp) {
1743 			if(put_user('\n', ((char __user *) buffer) + len))
1744 				return -EFAULT;
1745 			len++;
1746 		}
1747 		*lenp = len;
1748 		*ppos += len;
1749 	}
1750 	return 0;
1751 }
1752 
1753 /**
1754  * proc_dostring - read a string sysctl
1755  * @table: the sysctl table
1756  * @write: %TRUE if this is a write to the sysctl file
1757  * @buffer: the user buffer
1758  * @lenp: the size of the user buffer
1759  * @ppos: file position
1760  *
1761  * Reads/writes a string from/to the user buffer. If the kernel
1762  * buffer provided is not large enough to hold the string, the
1763  * string is truncated. The copied string is %NULL-terminated.
1764  * If the string is being read by the user process, it is copied
1765  * and a newline '\n' is added. It is truncated if the buffer is
1766  * not large enough.
1767  *
1768  * Returns 0 on success.
1769  */
1770 int proc_dostring(struct ctl_table *table, int write,
1771 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1772 {
1773 	return _proc_do_string(table->data, table->maxlen, write,
1774 			       buffer, lenp, ppos);
1775 }
1776 
1777 static size_t proc_skip_spaces(char **buf)
1778 {
1779 	size_t ret;
1780 	char *tmp = skip_spaces(*buf);
1781 	ret = tmp - *buf;
1782 	*buf = tmp;
1783 	return ret;
1784 }
1785 
1786 static void proc_skip_char(char **buf, size_t *size, const char v)
1787 {
1788 	while (*size) {
1789 		if (**buf != v)
1790 			break;
1791 		(*size)--;
1792 		(*buf)++;
1793 	}
1794 }
1795 
1796 #define TMPBUFLEN 22
1797 /**
1798  * proc_get_long - reads an ASCII formatted integer from a user buffer
1799  *
1800  * @buf: a kernel buffer
1801  * @size: size of the kernel buffer
1802  * @val: this is where the number will be stored
1803  * @neg: set to %TRUE if number is negative
1804  * @perm_tr: a vector which contains the allowed trailers
1805  * @perm_tr_len: size of the perm_tr vector
1806  * @tr: pointer to store the trailer character
1807  *
1808  * In case of success %0 is returned and @buf and @size are updated with
1809  * the amount of bytes read. If @tr is non-NULL and a trailing
1810  * character exists (size is non-zero after returning from this
1811  * function), @tr is updated with the trailing character.
1812  */
1813 static int proc_get_long(char **buf, size_t *size,
1814 			  unsigned long *val, bool *neg,
1815 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
1816 {
1817 	int len;
1818 	char *p, tmp[TMPBUFLEN];
1819 
1820 	if (!*size)
1821 		return -EINVAL;
1822 
1823 	len = *size;
1824 	if (len > TMPBUFLEN - 1)
1825 		len = TMPBUFLEN - 1;
1826 
1827 	memcpy(tmp, *buf, len);
1828 
1829 	tmp[len] = 0;
1830 	p = tmp;
1831 	if (*p == '-' && *size > 1) {
1832 		*neg = true;
1833 		p++;
1834 	} else
1835 		*neg = false;
1836 	if (!isdigit(*p))
1837 		return -EINVAL;
1838 
1839 	*val = simple_strtoul(p, &p, 0);
1840 
1841 	len = p - tmp;
1842 
1843 	/* We don't know if the next char is whitespace thus we may accept
1844 	 * invalid integers (e.g. 1234...a) or two integers instead of one
1845 	 * (e.g. 123...1). So lets not allow such large numbers. */
1846 	if (len == TMPBUFLEN - 1)
1847 		return -EINVAL;
1848 
1849 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
1850 		return -EINVAL;
1851 
1852 	if (tr && (len < *size))
1853 		*tr = *p;
1854 
1855 	*buf += len;
1856 	*size -= len;
1857 
1858 	return 0;
1859 }
1860 
1861 /**
1862  * proc_put_long - converts an integer to a decimal ASCII formatted string
1863  *
1864  * @buf: the user buffer
1865  * @size: the size of the user buffer
1866  * @val: the integer to be converted
1867  * @neg: sign of the number, %TRUE for negative
1868  *
1869  * In case of success %0 is returned and @buf and @size are updated with
1870  * the amount of bytes written.
1871  */
1872 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
1873 			  bool neg)
1874 {
1875 	int len;
1876 	char tmp[TMPBUFLEN], *p = tmp;
1877 
1878 	sprintf(p, "%s%lu", neg ? "-" : "", val);
1879 	len = strlen(tmp);
1880 	if (len > *size)
1881 		len = *size;
1882 	if (copy_to_user(*buf, tmp, len))
1883 		return -EFAULT;
1884 	*size -= len;
1885 	*buf += len;
1886 	return 0;
1887 }
1888 #undef TMPBUFLEN
1889 
1890 static int proc_put_char(void __user **buf, size_t *size, char c)
1891 {
1892 	if (*size) {
1893 		char __user **buffer = (char __user **)buf;
1894 		if (put_user(c, *buffer))
1895 			return -EFAULT;
1896 		(*size)--, (*buffer)++;
1897 		*buf = *buffer;
1898 	}
1899 	return 0;
1900 }
1901 
1902 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
1903 				 int *valp,
1904 				 int write, void *data)
1905 {
1906 	if (write) {
1907 		*valp = *negp ? -*lvalp : *lvalp;
1908 	} else {
1909 		int val = *valp;
1910 		if (val < 0) {
1911 			*negp = true;
1912 			*lvalp = (unsigned long)-val;
1913 		} else {
1914 			*negp = false;
1915 			*lvalp = (unsigned long)val;
1916 		}
1917 	}
1918 	return 0;
1919 }
1920 
1921 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
1922 
1923 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
1924 		  int write, void __user *buffer,
1925 		  size_t *lenp, loff_t *ppos,
1926 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
1927 			      int write, void *data),
1928 		  void *data)
1929 {
1930 	int *i, vleft, first = 1, err = 0;
1931 	unsigned long page = 0;
1932 	size_t left;
1933 	char *kbuf;
1934 
1935 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
1936 		*lenp = 0;
1937 		return 0;
1938 	}
1939 
1940 	i = (int *) tbl_data;
1941 	vleft = table->maxlen / sizeof(*i);
1942 	left = *lenp;
1943 
1944 	if (!conv)
1945 		conv = do_proc_dointvec_conv;
1946 
1947 	if (write) {
1948 		if (left > PAGE_SIZE - 1)
1949 			left = PAGE_SIZE - 1;
1950 		page = __get_free_page(GFP_TEMPORARY);
1951 		kbuf = (char *) page;
1952 		if (!kbuf)
1953 			return -ENOMEM;
1954 		if (copy_from_user(kbuf, buffer, left)) {
1955 			err = -EFAULT;
1956 			goto free;
1957 		}
1958 		kbuf[left] = 0;
1959 	}
1960 
1961 	for (; left && vleft--; i++, first=0) {
1962 		unsigned long lval;
1963 		bool neg;
1964 
1965 		if (write) {
1966 			left -= proc_skip_spaces(&kbuf);
1967 
1968 			if (!left)
1969 				break;
1970 			err = proc_get_long(&kbuf, &left, &lval, &neg,
1971 					     proc_wspace_sep,
1972 					     sizeof(proc_wspace_sep), NULL);
1973 			if (err)
1974 				break;
1975 			if (conv(&neg, &lval, i, 1, data)) {
1976 				err = -EINVAL;
1977 				break;
1978 			}
1979 		} else {
1980 			if (conv(&neg, &lval, i, 0, data)) {
1981 				err = -EINVAL;
1982 				break;
1983 			}
1984 			if (!first)
1985 				err = proc_put_char(&buffer, &left, '\t');
1986 			if (err)
1987 				break;
1988 			err = proc_put_long(&buffer, &left, lval, neg);
1989 			if (err)
1990 				break;
1991 		}
1992 	}
1993 
1994 	if (!write && !first && left && !err)
1995 		err = proc_put_char(&buffer, &left, '\n');
1996 	if (write && !err && left)
1997 		left -= proc_skip_spaces(&kbuf);
1998 free:
1999 	if (write) {
2000 		free_page(page);
2001 		if (first)
2002 			return err ? : -EINVAL;
2003 	}
2004 	*lenp -= left;
2005 	*ppos += *lenp;
2006 	return err;
2007 }
2008 
2009 static int do_proc_dointvec(struct ctl_table *table, int write,
2010 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2011 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2012 			      int write, void *data),
2013 		  void *data)
2014 {
2015 	return __do_proc_dointvec(table->data, table, write,
2016 			buffer, lenp, ppos, conv, data);
2017 }
2018 
2019 /**
2020  * proc_dointvec - read a vector of integers
2021  * @table: the sysctl table
2022  * @write: %TRUE if this is a write to the sysctl file
2023  * @buffer: the user buffer
2024  * @lenp: the size of the user buffer
2025  * @ppos: file position
2026  *
2027  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2028  * values from/to the user buffer, treated as an ASCII string.
2029  *
2030  * Returns 0 on success.
2031  */
2032 int proc_dointvec(struct ctl_table *table, int write,
2033 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2034 {
2035     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2036 		    	    NULL,NULL);
2037 }
2038 
2039 /*
2040  * Taint values can only be increased
2041  * This means we can safely use a temporary.
2042  */
2043 static int proc_taint(struct ctl_table *table, int write,
2044 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2045 {
2046 	struct ctl_table t;
2047 	unsigned long tmptaint = get_taint();
2048 	int err;
2049 
2050 	if (write && !capable(CAP_SYS_ADMIN))
2051 		return -EPERM;
2052 
2053 	t = *table;
2054 	t.data = &tmptaint;
2055 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2056 	if (err < 0)
2057 		return err;
2058 
2059 	if (write) {
2060 		/*
2061 		 * Poor man's atomic or. Not worth adding a primitive
2062 		 * to everyone's atomic.h for this
2063 		 */
2064 		int i;
2065 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2066 			if ((tmptaint >> i) & 1)
2067 				add_taint(i, LOCKDEP_STILL_OK);
2068 		}
2069 	}
2070 
2071 	return err;
2072 }
2073 
2074 #ifdef CONFIG_PRINTK
2075 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2076 				void __user *buffer, size_t *lenp, loff_t *ppos)
2077 {
2078 	if (write && !capable(CAP_SYS_ADMIN))
2079 		return -EPERM;
2080 
2081 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2082 }
2083 #endif
2084 
2085 struct do_proc_dointvec_minmax_conv_param {
2086 	int *min;
2087 	int *max;
2088 };
2089 
2090 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2091 					int *valp,
2092 					int write, void *data)
2093 {
2094 	struct do_proc_dointvec_minmax_conv_param *param = data;
2095 	if (write) {
2096 		int val = *negp ? -*lvalp : *lvalp;
2097 		if ((param->min && *param->min > val) ||
2098 		    (param->max && *param->max < val))
2099 			return -EINVAL;
2100 		*valp = val;
2101 	} else {
2102 		int val = *valp;
2103 		if (val < 0) {
2104 			*negp = true;
2105 			*lvalp = (unsigned long)-val;
2106 		} else {
2107 			*negp = false;
2108 			*lvalp = (unsigned long)val;
2109 		}
2110 	}
2111 	return 0;
2112 }
2113 
2114 /**
2115  * proc_dointvec_minmax - read a vector of integers with min/max values
2116  * @table: the sysctl table
2117  * @write: %TRUE if this is a write to the sysctl file
2118  * @buffer: the user buffer
2119  * @lenp: the size of the user buffer
2120  * @ppos: file position
2121  *
2122  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2123  * values from/to the user buffer, treated as an ASCII string.
2124  *
2125  * This routine will ensure the values are within the range specified by
2126  * table->extra1 (min) and table->extra2 (max).
2127  *
2128  * Returns 0 on success.
2129  */
2130 int proc_dointvec_minmax(struct ctl_table *table, int write,
2131 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2132 {
2133 	struct do_proc_dointvec_minmax_conv_param param = {
2134 		.min = (int *) table->extra1,
2135 		.max = (int *) table->extra2,
2136 	};
2137 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2138 				do_proc_dointvec_minmax_conv, &param);
2139 }
2140 
2141 static void validate_coredump_safety(void)
2142 {
2143 #ifdef CONFIG_COREDUMP
2144 	if (suid_dumpable == SUID_DUMP_ROOT &&
2145 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2146 		printk(KERN_WARNING "Unsafe core_pattern used with "\
2147 			"suid_dumpable=2. Pipe handler or fully qualified "\
2148 			"core dump path required.\n");
2149 	}
2150 #endif
2151 }
2152 
2153 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2154 		void __user *buffer, size_t *lenp, loff_t *ppos)
2155 {
2156 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2157 	if (!error)
2158 		validate_coredump_safety();
2159 	return error;
2160 }
2161 
2162 #ifdef CONFIG_COREDUMP
2163 static int proc_dostring_coredump(struct ctl_table *table, int write,
2164 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2165 {
2166 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2167 	if (!error)
2168 		validate_coredump_safety();
2169 	return error;
2170 }
2171 #endif
2172 
2173 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2174 				     void __user *buffer,
2175 				     size_t *lenp, loff_t *ppos,
2176 				     unsigned long convmul,
2177 				     unsigned long convdiv)
2178 {
2179 	unsigned long *i, *min, *max;
2180 	int vleft, first = 1, err = 0;
2181 	unsigned long page = 0;
2182 	size_t left;
2183 	char *kbuf;
2184 
2185 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2186 		*lenp = 0;
2187 		return 0;
2188 	}
2189 
2190 	i = (unsigned long *) data;
2191 	min = (unsigned long *) table->extra1;
2192 	max = (unsigned long *) table->extra2;
2193 	vleft = table->maxlen / sizeof(unsigned long);
2194 	left = *lenp;
2195 
2196 	if (write) {
2197 		if (left > PAGE_SIZE - 1)
2198 			left = PAGE_SIZE - 1;
2199 		page = __get_free_page(GFP_TEMPORARY);
2200 		kbuf = (char *) page;
2201 		if (!kbuf)
2202 			return -ENOMEM;
2203 		if (copy_from_user(kbuf, buffer, left)) {
2204 			err = -EFAULT;
2205 			goto free;
2206 		}
2207 		kbuf[left] = 0;
2208 	}
2209 
2210 	for (; left && vleft--; i++, first = 0) {
2211 		unsigned long val;
2212 
2213 		if (write) {
2214 			bool neg;
2215 
2216 			left -= proc_skip_spaces(&kbuf);
2217 
2218 			err = proc_get_long(&kbuf, &left, &val, &neg,
2219 					     proc_wspace_sep,
2220 					     sizeof(proc_wspace_sep), NULL);
2221 			if (err)
2222 				break;
2223 			if (neg)
2224 				continue;
2225 			if ((min && val < *min) || (max && val > *max))
2226 				continue;
2227 			*i = val;
2228 		} else {
2229 			val = convdiv * (*i) / convmul;
2230 			if (!first) {
2231 				err = proc_put_char(&buffer, &left, '\t');
2232 				if (err)
2233 					break;
2234 			}
2235 			err = proc_put_long(&buffer, &left, val, false);
2236 			if (err)
2237 				break;
2238 		}
2239 	}
2240 
2241 	if (!write && !first && left && !err)
2242 		err = proc_put_char(&buffer, &left, '\n');
2243 	if (write && !err)
2244 		left -= proc_skip_spaces(&kbuf);
2245 free:
2246 	if (write) {
2247 		free_page(page);
2248 		if (first)
2249 			return err ? : -EINVAL;
2250 	}
2251 	*lenp -= left;
2252 	*ppos += *lenp;
2253 	return err;
2254 }
2255 
2256 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2257 				     void __user *buffer,
2258 				     size_t *lenp, loff_t *ppos,
2259 				     unsigned long convmul,
2260 				     unsigned long convdiv)
2261 {
2262 	return __do_proc_doulongvec_minmax(table->data, table, write,
2263 			buffer, lenp, ppos, convmul, convdiv);
2264 }
2265 
2266 /**
2267  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2268  * @table: the sysctl table
2269  * @write: %TRUE if this is a write to the sysctl file
2270  * @buffer: the user buffer
2271  * @lenp: the size of the user buffer
2272  * @ppos: file position
2273  *
2274  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2275  * values from/to the user buffer, treated as an ASCII string.
2276  *
2277  * This routine will ensure the values are within the range specified by
2278  * table->extra1 (min) and table->extra2 (max).
2279  *
2280  * Returns 0 on success.
2281  */
2282 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2283 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2284 {
2285     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2286 }
2287 
2288 /**
2289  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2290  * @table: the sysctl table
2291  * @write: %TRUE if this is a write to the sysctl file
2292  * @buffer: the user buffer
2293  * @lenp: the size of the user buffer
2294  * @ppos: file position
2295  *
2296  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2297  * values from/to the user buffer, treated as an ASCII string. The values
2298  * are treated as milliseconds, and converted to jiffies when they are stored.
2299  *
2300  * This routine will ensure the values are within the range specified by
2301  * table->extra1 (min) and table->extra2 (max).
2302  *
2303  * Returns 0 on success.
2304  */
2305 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2306 				      void __user *buffer,
2307 				      size_t *lenp, loff_t *ppos)
2308 {
2309     return do_proc_doulongvec_minmax(table, write, buffer,
2310 				     lenp, ppos, HZ, 1000l);
2311 }
2312 
2313 
2314 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2315 					 int *valp,
2316 					 int write, void *data)
2317 {
2318 	if (write) {
2319 		if (*lvalp > LONG_MAX / HZ)
2320 			return 1;
2321 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2322 	} else {
2323 		int val = *valp;
2324 		unsigned long lval;
2325 		if (val < 0) {
2326 			*negp = true;
2327 			lval = (unsigned long)-val;
2328 		} else {
2329 			*negp = false;
2330 			lval = (unsigned long)val;
2331 		}
2332 		*lvalp = lval / HZ;
2333 	}
2334 	return 0;
2335 }
2336 
2337 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2338 						int *valp,
2339 						int write, void *data)
2340 {
2341 	if (write) {
2342 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2343 			return 1;
2344 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2345 	} else {
2346 		int val = *valp;
2347 		unsigned long lval;
2348 		if (val < 0) {
2349 			*negp = true;
2350 			lval = (unsigned long)-val;
2351 		} else {
2352 			*negp = false;
2353 			lval = (unsigned long)val;
2354 		}
2355 		*lvalp = jiffies_to_clock_t(lval);
2356 	}
2357 	return 0;
2358 }
2359 
2360 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2361 					    int *valp,
2362 					    int write, void *data)
2363 {
2364 	if (write) {
2365 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2366 
2367 		if (jif > INT_MAX)
2368 			return 1;
2369 		*valp = (int)jif;
2370 	} else {
2371 		int val = *valp;
2372 		unsigned long lval;
2373 		if (val < 0) {
2374 			*negp = true;
2375 			lval = (unsigned long)-val;
2376 		} else {
2377 			*negp = false;
2378 			lval = (unsigned long)val;
2379 		}
2380 		*lvalp = jiffies_to_msecs(lval);
2381 	}
2382 	return 0;
2383 }
2384 
2385 /**
2386  * proc_dointvec_jiffies - read a vector of integers as seconds
2387  * @table: the sysctl table
2388  * @write: %TRUE if this is a write to the sysctl file
2389  * @buffer: the user buffer
2390  * @lenp: the size of the user buffer
2391  * @ppos: file position
2392  *
2393  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2394  * values from/to the user buffer, treated as an ASCII string.
2395  * The values read are assumed to be in seconds, and are converted into
2396  * jiffies.
2397  *
2398  * Returns 0 on success.
2399  */
2400 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2401 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2402 {
2403     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2404 		    	    do_proc_dointvec_jiffies_conv,NULL);
2405 }
2406 
2407 /**
2408  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2409  * @table: the sysctl table
2410  * @write: %TRUE if this is a write to the sysctl file
2411  * @buffer: the user buffer
2412  * @lenp: the size of the user buffer
2413  * @ppos: pointer to the file position
2414  *
2415  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2416  * values from/to the user buffer, treated as an ASCII string.
2417  * The values read are assumed to be in 1/USER_HZ seconds, and
2418  * are converted into jiffies.
2419  *
2420  * Returns 0 on success.
2421  */
2422 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2423 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2424 {
2425     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2426 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2427 }
2428 
2429 /**
2430  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2431  * @table: the sysctl table
2432  * @write: %TRUE if this is a write to the sysctl file
2433  * @buffer: the user buffer
2434  * @lenp: the size of the user buffer
2435  * @ppos: file position
2436  * @ppos: the current position in the file
2437  *
2438  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2439  * values from/to the user buffer, treated as an ASCII string.
2440  * The values read are assumed to be in 1/1000 seconds, and
2441  * are converted into jiffies.
2442  *
2443  * Returns 0 on success.
2444  */
2445 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2446 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2447 {
2448 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2449 				do_proc_dointvec_ms_jiffies_conv, NULL);
2450 }
2451 
2452 static int proc_do_cad_pid(struct ctl_table *table, int write,
2453 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2454 {
2455 	struct pid *new_pid;
2456 	pid_t tmp;
2457 	int r;
2458 
2459 	tmp = pid_vnr(cad_pid);
2460 
2461 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2462 			       lenp, ppos, NULL, NULL);
2463 	if (r || !write)
2464 		return r;
2465 
2466 	new_pid = find_get_pid(tmp);
2467 	if (!new_pid)
2468 		return -ESRCH;
2469 
2470 	put_pid(xchg(&cad_pid, new_pid));
2471 	return 0;
2472 }
2473 
2474 /**
2475  * proc_do_large_bitmap - read/write from/to a large bitmap
2476  * @table: the sysctl table
2477  * @write: %TRUE if this is a write to the sysctl file
2478  * @buffer: the user buffer
2479  * @lenp: the size of the user buffer
2480  * @ppos: file position
2481  *
2482  * The bitmap is stored at table->data and the bitmap length (in bits)
2483  * in table->maxlen.
2484  *
2485  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2486  * large bitmaps may be represented in a compact manner. Writing into
2487  * the file will clear the bitmap then update it with the given input.
2488  *
2489  * Returns 0 on success.
2490  */
2491 int proc_do_large_bitmap(struct ctl_table *table, int write,
2492 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2493 {
2494 	int err = 0;
2495 	bool first = 1;
2496 	size_t left = *lenp;
2497 	unsigned long bitmap_len = table->maxlen;
2498 	unsigned long *bitmap = (unsigned long *) table->data;
2499 	unsigned long *tmp_bitmap = NULL;
2500 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2501 
2502 	if (!bitmap_len || !left || (*ppos && !write)) {
2503 		*lenp = 0;
2504 		return 0;
2505 	}
2506 
2507 	if (write) {
2508 		unsigned long page = 0;
2509 		char *kbuf;
2510 
2511 		if (left > PAGE_SIZE - 1)
2512 			left = PAGE_SIZE - 1;
2513 
2514 		page = __get_free_page(GFP_TEMPORARY);
2515 		kbuf = (char *) page;
2516 		if (!kbuf)
2517 			return -ENOMEM;
2518 		if (copy_from_user(kbuf, buffer, left)) {
2519 			free_page(page);
2520 			return -EFAULT;
2521                 }
2522 		kbuf[left] = 0;
2523 
2524 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2525 				     GFP_KERNEL);
2526 		if (!tmp_bitmap) {
2527 			free_page(page);
2528 			return -ENOMEM;
2529 		}
2530 		proc_skip_char(&kbuf, &left, '\n');
2531 		while (!err && left) {
2532 			unsigned long val_a, val_b;
2533 			bool neg;
2534 
2535 			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2536 					     sizeof(tr_a), &c);
2537 			if (err)
2538 				break;
2539 			if (val_a >= bitmap_len || neg) {
2540 				err = -EINVAL;
2541 				break;
2542 			}
2543 
2544 			val_b = val_a;
2545 			if (left) {
2546 				kbuf++;
2547 				left--;
2548 			}
2549 
2550 			if (c == '-') {
2551 				err = proc_get_long(&kbuf, &left, &val_b,
2552 						     &neg, tr_b, sizeof(tr_b),
2553 						     &c);
2554 				if (err)
2555 					break;
2556 				if (val_b >= bitmap_len || neg ||
2557 				    val_a > val_b) {
2558 					err = -EINVAL;
2559 					break;
2560 				}
2561 				if (left) {
2562 					kbuf++;
2563 					left--;
2564 				}
2565 			}
2566 
2567 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2568 			first = 0;
2569 			proc_skip_char(&kbuf, &left, '\n');
2570 		}
2571 		free_page(page);
2572 	} else {
2573 		unsigned long bit_a, bit_b = 0;
2574 
2575 		while (left) {
2576 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2577 			if (bit_a >= bitmap_len)
2578 				break;
2579 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2580 						   bit_a + 1) - 1;
2581 
2582 			if (!first) {
2583 				err = proc_put_char(&buffer, &left, ',');
2584 				if (err)
2585 					break;
2586 			}
2587 			err = proc_put_long(&buffer, &left, bit_a, false);
2588 			if (err)
2589 				break;
2590 			if (bit_a != bit_b) {
2591 				err = proc_put_char(&buffer, &left, '-');
2592 				if (err)
2593 					break;
2594 				err = proc_put_long(&buffer, &left, bit_b, false);
2595 				if (err)
2596 					break;
2597 			}
2598 
2599 			first = 0; bit_b++;
2600 		}
2601 		if (!err)
2602 			err = proc_put_char(&buffer, &left, '\n');
2603 	}
2604 
2605 	if (!err) {
2606 		if (write) {
2607 			if (*ppos)
2608 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2609 			else
2610 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2611 		}
2612 		kfree(tmp_bitmap);
2613 		*lenp -= left;
2614 		*ppos += *lenp;
2615 		return 0;
2616 	} else {
2617 		kfree(tmp_bitmap);
2618 		return err;
2619 	}
2620 }
2621 
2622 #else /* CONFIG_PROC_SYSCTL */
2623 
2624 int proc_dostring(struct ctl_table *table, int write,
2625 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2626 {
2627 	return -ENOSYS;
2628 }
2629 
2630 int proc_dointvec(struct ctl_table *table, int write,
2631 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2632 {
2633 	return -ENOSYS;
2634 }
2635 
2636 int proc_dointvec_minmax(struct ctl_table *table, int write,
2637 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2638 {
2639 	return -ENOSYS;
2640 }
2641 
2642 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2643 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2644 {
2645 	return -ENOSYS;
2646 }
2647 
2648 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2649 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2650 {
2651 	return -ENOSYS;
2652 }
2653 
2654 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2655 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2656 {
2657 	return -ENOSYS;
2658 }
2659 
2660 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2661 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2662 {
2663 	return -ENOSYS;
2664 }
2665 
2666 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2667 				      void __user *buffer,
2668 				      size_t *lenp, loff_t *ppos)
2669 {
2670     return -ENOSYS;
2671 }
2672 
2673 
2674 #endif /* CONFIG_PROC_SYSCTL */
2675 
2676 /*
2677  * No sense putting this after each symbol definition, twice,
2678  * exception granted :-)
2679  */
2680 EXPORT_SYMBOL(proc_dointvec);
2681 EXPORT_SYMBOL(proc_dointvec_jiffies);
2682 EXPORT_SYMBOL(proc_dointvec_minmax);
2683 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2684 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2685 EXPORT_SYMBOL(proc_dostring);
2686 EXPORT_SYMBOL(proc_doulongvec_minmax);
2687 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2688