ipv6: Use ip6_dst_hoplimit() instead of direct dst_metric() calls.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / sysctl.c
blobb65bf634035ed0684693b9c7c02b3229c8d68e0d
1 /*
2 * sysctl.c: General linux system control interface
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
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/signal.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/ctype.h>
30 #include <linux/kmemcheck.h>
31 #include <linux/fs.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/ratelimit.h>
40 #include <linux/compaction.h>
41 #include <linux/hugetlb.h>
42 #include <linux/initrd.h>
43 #include <linux/key.h>
44 #include <linux/times.h>
45 #include <linux/limits.h>
46 #include <linux/dcache.h>
47 #include <linux/dnotify.h>
48 #include <linux/syscalls.h>
49 #include <linux/vmstat.h>
50 #include <linux/nfs_fs.h>
51 #include <linux/acpi.h>
52 #include <linux/reboot.h>
53 #include <linux/ftrace.h>
54 #include <linux/perf_event.h>
55 #include <linux/kprobes.h>
56 #include <linux/pipe_fs_i.h>
57 #include <linux/oom.h>
59 #include <asm/uaccess.h>
60 #include <asm/processor.h>
62 #ifdef CONFIG_X86
63 #include <asm/nmi.h>
64 #include <asm/stacktrace.h>
65 #include <asm/io.h>
66 #endif
67 #ifdef CONFIG_BSD_PROCESS_ACCT
68 #include <linux/acct.h>
69 #endif
70 #ifdef CONFIG_RT_MUTEXES
71 #include <linux/rtmutex.h>
72 #endif
73 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
74 #include <linux/lockdep.h>
75 #endif
76 #ifdef CONFIG_CHR_DEV_SG
77 #include <scsi/sg.h>
78 #endif
80 #ifdef CONFIG_LOCKUP_DETECTOR
81 #include <linux/nmi.h>
82 #endif
85 #if defined(CONFIG_SYSCTL)
87 /* External variables not in a header file. */
88 extern int sysctl_overcommit_memory;
89 extern int sysctl_overcommit_ratio;
90 extern int max_threads;
91 extern int core_uses_pid;
92 extern int suid_dumpable;
93 extern char core_pattern[];
94 extern unsigned int core_pipe_limit;
95 extern int pid_max;
96 extern int min_free_kbytes;
97 extern int pid_max_min, pid_max_max;
98 extern int sysctl_drop_caches;
99 extern int percpu_pagelist_fraction;
100 extern int compat_log;
101 extern int latencytop_enabled;
102 extern int sysctl_nr_open_min, sysctl_nr_open_max;
103 #ifndef CONFIG_MMU
104 extern int sysctl_nr_trim_pages;
105 #endif
106 #ifdef CONFIG_BLOCK
107 extern int blk_iopoll_enabled;
108 #endif
110 /* Constants used for minimum and maximum */
111 #ifdef CONFIG_LOCKUP_DETECTOR
112 static int sixty = 60;
113 static int neg_one = -1;
114 #endif
116 static int zero;
117 static int __maybe_unused one = 1;
118 static int __maybe_unused two = 2;
119 static unsigned long one_ul = 1;
120 static int one_hundred = 100;
121 #ifdef CONFIG_PRINTK
122 static int ten_thousand = 10000;
123 #endif
125 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
126 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
128 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
129 static int maxolduid = 65535;
130 static int minolduid;
131 static int min_percpu_pagelist_fract = 8;
133 static int ngroups_max = NGROUPS_MAX;
135 #ifdef CONFIG_INOTIFY_USER
136 #include <linux/inotify.h>
137 #endif
138 #ifdef CONFIG_SPARC
139 #include <asm/system.h>
140 #endif
142 #ifdef CONFIG_SPARC64
143 extern int sysctl_tsb_ratio;
144 #endif
146 #ifdef __hppa__
147 extern int pwrsw_enabled;
148 extern int unaligned_enabled;
149 #endif
151 #ifdef CONFIG_S390
152 #ifdef CONFIG_MATHEMU
153 extern int sysctl_ieee_emulation_warnings;
154 #endif
155 extern int sysctl_userprocess_debug;
156 extern int spin_retry;
157 #endif
159 #ifdef CONFIG_IA64
160 extern int no_unaligned_warning;
161 extern int unaligned_dump_stack;
162 #endif
164 #ifdef CONFIG_PROC_SYSCTL
165 static int proc_do_cad_pid(struct ctl_table *table, int write,
166 void __user *buffer, size_t *lenp, loff_t *ppos);
167 static int proc_taint(struct ctl_table *table, int write,
168 void __user *buffer, size_t *lenp, loff_t *ppos);
169 #endif
171 #ifdef CONFIG_MAGIC_SYSRQ
172 static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
174 static int sysrq_sysctl_handler(ctl_table *table, int write,
175 void __user *buffer, size_t *lenp,
176 loff_t *ppos)
178 int error;
180 error = proc_dointvec(table, write, buffer, lenp, ppos);
181 if (error)
182 return error;
184 if (write)
185 sysrq_toggle_support(__sysrq_enabled);
187 return 0;
190 #endif
192 static struct ctl_table root_table[];
193 static struct ctl_table_root sysctl_table_root;
194 static struct ctl_table_header root_table_header = {
195 .count = 1,
196 .ctl_table = root_table,
197 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
198 .root = &sysctl_table_root,
199 .set = &sysctl_table_root.default_set,
201 static struct ctl_table_root sysctl_table_root = {
202 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
203 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
206 static struct ctl_table kern_table[];
207 static struct ctl_table vm_table[];
208 static struct ctl_table fs_table[];
209 static struct ctl_table debug_table[];
210 static struct ctl_table dev_table[];
211 extern struct ctl_table random_table[];
212 #ifdef CONFIG_EPOLL
213 extern struct ctl_table epoll_table[];
214 #endif
216 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
217 int sysctl_legacy_va_layout;
218 #endif
220 /* The default sysctl tables: */
222 static struct ctl_table root_table[] = {
224 .procname = "kernel",
225 .mode = 0555,
226 .child = kern_table,
229 .procname = "vm",
230 .mode = 0555,
231 .child = vm_table,
234 .procname = "fs",
235 .mode = 0555,
236 .child = fs_table,
239 .procname = "debug",
240 .mode = 0555,
241 .child = debug_table,
244 .procname = "dev",
245 .mode = 0555,
246 .child = dev_table,
249 * NOTE: do not add new entries to this table unless you have read
250 * Documentation/sysctl/ctl_unnumbered.txt
255 #ifdef CONFIG_SCHED_DEBUG
256 static int min_sched_granularity_ns = 100000; /* 100 usecs */
257 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
258 static int min_wakeup_granularity_ns; /* 0 usecs */
259 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
260 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
261 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
262 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
263 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
264 #endif
266 #ifdef CONFIG_COMPACTION
267 static int min_extfrag_threshold;
268 static int max_extfrag_threshold = 1000;
269 #endif
271 static struct ctl_table kern_table[] = {
273 .procname = "sched_child_runs_first",
274 .data = &sysctl_sched_child_runs_first,
275 .maxlen = sizeof(unsigned int),
276 .mode = 0644,
277 .proc_handler = proc_dointvec,
279 #ifdef CONFIG_SCHED_DEBUG
281 .procname = "sched_min_granularity_ns",
282 .data = &sysctl_sched_min_granularity,
283 .maxlen = sizeof(unsigned int),
284 .mode = 0644,
285 .proc_handler = sched_proc_update_handler,
286 .extra1 = &min_sched_granularity_ns,
287 .extra2 = &max_sched_granularity_ns,
290 .procname = "sched_latency_ns",
291 .data = &sysctl_sched_latency,
292 .maxlen = sizeof(unsigned int),
293 .mode = 0644,
294 .proc_handler = sched_proc_update_handler,
295 .extra1 = &min_sched_granularity_ns,
296 .extra2 = &max_sched_granularity_ns,
299 .procname = "sched_wakeup_granularity_ns",
300 .data = &sysctl_sched_wakeup_granularity,
301 .maxlen = sizeof(unsigned int),
302 .mode = 0644,
303 .proc_handler = sched_proc_update_handler,
304 .extra1 = &min_wakeup_granularity_ns,
305 .extra2 = &max_wakeup_granularity_ns,
308 .procname = "sched_shares_ratelimit",
309 .data = &sysctl_sched_shares_ratelimit,
310 .maxlen = sizeof(unsigned int),
311 .mode = 0644,
312 .proc_handler = sched_proc_update_handler,
313 .extra1 = &min_sched_shares_ratelimit,
314 .extra2 = &max_sched_shares_ratelimit,
317 .procname = "sched_tunable_scaling",
318 .data = &sysctl_sched_tunable_scaling,
319 .maxlen = sizeof(enum sched_tunable_scaling),
320 .mode = 0644,
321 .proc_handler = sched_proc_update_handler,
322 .extra1 = &min_sched_tunable_scaling,
323 .extra2 = &max_sched_tunable_scaling,
326 .procname = "sched_shares_thresh",
327 .data = &sysctl_sched_shares_thresh,
328 .maxlen = sizeof(unsigned int),
329 .mode = 0644,
330 .proc_handler = proc_dointvec_minmax,
331 .extra1 = &zero,
334 .procname = "sched_migration_cost",
335 .data = &sysctl_sched_migration_cost,
336 .maxlen = sizeof(unsigned int),
337 .mode = 0644,
338 .proc_handler = proc_dointvec,
341 .procname = "sched_nr_migrate",
342 .data = &sysctl_sched_nr_migrate,
343 .maxlen = sizeof(unsigned int),
344 .mode = 0644,
345 .proc_handler = proc_dointvec,
348 .procname = "sched_time_avg",
349 .data = &sysctl_sched_time_avg,
350 .maxlen = sizeof(unsigned int),
351 .mode = 0644,
352 .proc_handler = proc_dointvec,
355 .procname = "timer_migration",
356 .data = &sysctl_timer_migration,
357 .maxlen = sizeof(unsigned int),
358 .mode = 0644,
359 .proc_handler = proc_dointvec_minmax,
360 .extra1 = &zero,
361 .extra2 = &one,
363 #endif
365 .procname = "sched_rt_period_us",
366 .data = &sysctl_sched_rt_period,
367 .maxlen = sizeof(unsigned int),
368 .mode = 0644,
369 .proc_handler = sched_rt_handler,
372 .procname = "sched_rt_runtime_us",
373 .data = &sysctl_sched_rt_runtime,
374 .maxlen = sizeof(int),
375 .mode = 0644,
376 .proc_handler = sched_rt_handler,
379 .procname = "sched_compat_yield",
380 .data = &sysctl_sched_compat_yield,
381 .maxlen = sizeof(unsigned int),
382 .mode = 0644,
383 .proc_handler = proc_dointvec,
385 #ifdef CONFIG_PROVE_LOCKING
387 .procname = "prove_locking",
388 .data = &prove_locking,
389 .maxlen = sizeof(int),
390 .mode = 0644,
391 .proc_handler = proc_dointvec,
393 #endif
394 #ifdef CONFIG_LOCK_STAT
396 .procname = "lock_stat",
397 .data = &lock_stat,
398 .maxlen = sizeof(int),
399 .mode = 0644,
400 .proc_handler = proc_dointvec,
402 #endif
404 .procname = "panic",
405 .data = &panic_timeout,
406 .maxlen = sizeof(int),
407 .mode = 0644,
408 .proc_handler = proc_dointvec,
411 .procname = "core_uses_pid",
412 .data = &core_uses_pid,
413 .maxlen = sizeof(int),
414 .mode = 0644,
415 .proc_handler = proc_dointvec,
418 .procname = "core_pattern",
419 .data = core_pattern,
420 .maxlen = CORENAME_MAX_SIZE,
421 .mode = 0644,
422 .proc_handler = proc_dostring,
425 .procname = "core_pipe_limit",
426 .data = &core_pipe_limit,
427 .maxlen = sizeof(unsigned int),
428 .mode = 0644,
429 .proc_handler = proc_dointvec,
431 #ifdef CONFIG_PROC_SYSCTL
433 .procname = "tainted",
434 .maxlen = sizeof(long),
435 .mode = 0644,
436 .proc_handler = proc_taint,
438 #endif
439 #ifdef CONFIG_LATENCYTOP
441 .procname = "latencytop",
442 .data = &latencytop_enabled,
443 .maxlen = sizeof(int),
444 .mode = 0644,
445 .proc_handler = proc_dointvec,
447 #endif
448 #ifdef CONFIG_BLK_DEV_INITRD
450 .procname = "real-root-dev",
451 .data = &real_root_dev,
452 .maxlen = sizeof(int),
453 .mode = 0644,
454 .proc_handler = proc_dointvec,
456 #endif
458 .procname = "print-fatal-signals",
459 .data = &print_fatal_signals,
460 .maxlen = sizeof(int),
461 .mode = 0644,
462 .proc_handler = proc_dointvec,
464 #ifdef CONFIG_SPARC
466 .procname = "reboot-cmd",
467 .data = reboot_command,
468 .maxlen = 256,
469 .mode = 0644,
470 .proc_handler = proc_dostring,
473 .procname = "stop-a",
474 .data = &stop_a_enabled,
475 .maxlen = sizeof (int),
476 .mode = 0644,
477 .proc_handler = proc_dointvec,
480 .procname = "scons-poweroff",
481 .data = &scons_pwroff,
482 .maxlen = sizeof (int),
483 .mode = 0644,
484 .proc_handler = proc_dointvec,
486 #endif
487 #ifdef CONFIG_SPARC64
489 .procname = "tsb-ratio",
490 .data = &sysctl_tsb_ratio,
491 .maxlen = sizeof (int),
492 .mode = 0644,
493 .proc_handler = proc_dointvec,
495 #endif
496 #ifdef __hppa__
498 .procname = "soft-power",
499 .data = &pwrsw_enabled,
500 .maxlen = sizeof (int),
501 .mode = 0644,
502 .proc_handler = proc_dointvec,
505 .procname = "unaligned-trap",
506 .data = &unaligned_enabled,
507 .maxlen = sizeof (int),
508 .mode = 0644,
509 .proc_handler = proc_dointvec,
511 #endif
513 .procname = "ctrl-alt-del",
514 .data = &C_A_D,
515 .maxlen = sizeof(int),
516 .mode = 0644,
517 .proc_handler = proc_dointvec,
519 #ifdef CONFIG_FUNCTION_TRACER
521 .procname = "ftrace_enabled",
522 .data = &ftrace_enabled,
523 .maxlen = sizeof(int),
524 .mode = 0644,
525 .proc_handler = ftrace_enable_sysctl,
527 #endif
528 #ifdef CONFIG_STACK_TRACER
530 .procname = "stack_tracer_enabled",
531 .data = &stack_tracer_enabled,
532 .maxlen = sizeof(int),
533 .mode = 0644,
534 .proc_handler = stack_trace_sysctl,
536 #endif
537 #ifdef CONFIG_TRACING
539 .procname = "ftrace_dump_on_oops",
540 .data = &ftrace_dump_on_oops,
541 .maxlen = sizeof(int),
542 .mode = 0644,
543 .proc_handler = proc_dointvec,
545 #endif
546 #ifdef CONFIG_MODULES
548 .procname = "modprobe",
549 .data = &modprobe_path,
550 .maxlen = KMOD_PATH_LEN,
551 .mode = 0644,
552 .proc_handler = proc_dostring,
555 .procname = "modules_disabled",
556 .data = &modules_disabled,
557 .maxlen = sizeof(int),
558 .mode = 0644,
559 /* only handle a transition from default "0" to "1" */
560 .proc_handler = proc_dointvec_minmax,
561 .extra1 = &one,
562 .extra2 = &one,
564 #endif
565 #ifdef CONFIG_HOTPLUG
567 .procname = "hotplug",
568 .data = &uevent_helper,
569 .maxlen = UEVENT_HELPER_PATH_LEN,
570 .mode = 0644,
571 .proc_handler = proc_dostring,
573 #endif
574 #ifdef CONFIG_CHR_DEV_SG
576 .procname = "sg-big-buff",
577 .data = &sg_big_buff,
578 .maxlen = sizeof (int),
579 .mode = 0444,
580 .proc_handler = proc_dointvec,
582 #endif
583 #ifdef CONFIG_BSD_PROCESS_ACCT
585 .procname = "acct",
586 .data = &acct_parm,
587 .maxlen = 3*sizeof(int),
588 .mode = 0644,
589 .proc_handler = proc_dointvec,
591 #endif
592 #ifdef CONFIG_MAGIC_SYSRQ
594 .procname = "sysrq",
595 .data = &__sysrq_enabled,
596 .maxlen = sizeof (int),
597 .mode = 0644,
598 .proc_handler = sysrq_sysctl_handler,
600 #endif
601 #ifdef CONFIG_PROC_SYSCTL
603 .procname = "cad_pid",
604 .data = NULL,
605 .maxlen = sizeof (int),
606 .mode = 0600,
607 .proc_handler = proc_do_cad_pid,
609 #endif
611 .procname = "threads-max",
612 .data = &max_threads,
613 .maxlen = sizeof(int),
614 .mode = 0644,
615 .proc_handler = proc_dointvec,
618 .procname = "random",
619 .mode = 0555,
620 .child = random_table,
623 .procname = "overflowuid",
624 .data = &overflowuid,
625 .maxlen = sizeof(int),
626 .mode = 0644,
627 .proc_handler = proc_dointvec_minmax,
628 .extra1 = &minolduid,
629 .extra2 = &maxolduid,
632 .procname = "overflowgid",
633 .data = &overflowgid,
634 .maxlen = sizeof(int),
635 .mode = 0644,
636 .proc_handler = proc_dointvec_minmax,
637 .extra1 = &minolduid,
638 .extra2 = &maxolduid,
640 #ifdef CONFIG_S390
641 #ifdef CONFIG_MATHEMU
643 .procname = "ieee_emulation_warnings",
644 .data = &sysctl_ieee_emulation_warnings,
645 .maxlen = sizeof(int),
646 .mode = 0644,
647 .proc_handler = proc_dointvec,
649 #endif
651 .procname = "userprocess_debug",
652 .data = &show_unhandled_signals,
653 .maxlen = sizeof(int),
654 .mode = 0644,
655 .proc_handler = proc_dointvec,
657 #endif
659 .procname = "pid_max",
660 .data = &pid_max,
661 .maxlen = sizeof (int),
662 .mode = 0644,
663 .proc_handler = proc_dointvec_minmax,
664 .extra1 = &pid_max_min,
665 .extra2 = &pid_max_max,
668 .procname = "panic_on_oops",
669 .data = &panic_on_oops,
670 .maxlen = sizeof(int),
671 .mode = 0644,
672 .proc_handler = proc_dointvec,
674 #if defined CONFIG_PRINTK
676 .procname = "printk",
677 .data = &console_loglevel,
678 .maxlen = 4*sizeof(int),
679 .mode = 0644,
680 .proc_handler = proc_dointvec,
683 .procname = "printk_ratelimit",
684 .data = &printk_ratelimit_state.interval,
685 .maxlen = sizeof(int),
686 .mode = 0644,
687 .proc_handler = proc_dointvec_jiffies,
690 .procname = "printk_ratelimit_burst",
691 .data = &printk_ratelimit_state.burst,
692 .maxlen = sizeof(int),
693 .mode = 0644,
694 .proc_handler = proc_dointvec,
697 .procname = "printk_delay",
698 .data = &printk_delay_msec,
699 .maxlen = sizeof(int),
700 .mode = 0644,
701 .proc_handler = proc_dointvec_minmax,
702 .extra1 = &zero,
703 .extra2 = &ten_thousand,
705 #endif
707 .procname = "dmesg_restrict",
708 .data = &dmesg_restrict,
709 .maxlen = sizeof(int),
710 .mode = 0644,
711 .proc_handler = proc_dointvec_minmax,
712 .extra1 = &zero,
713 .extra2 = &one,
716 .procname = "ngroups_max",
717 .data = &ngroups_max,
718 .maxlen = sizeof (int),
719 .mode = 0444,
720 .proc_handler = proc_dointvec,
722 #if defined(CONFIG_LOCKUP_DETECTOR)
724 .procname = "watchdog",
725 .data = &watchdog_enabled,
726 .maxlen = sizeof (int),
727 .mode = 0644,
728 .proc_handler = proc_dowatchdog_enabled,
731 .procname = "watchdog_thresh",
732 .data = &softlockup_thresh,
733 .maxlen = sizeof(int),
734 .mode = 0644,
735 .proc_handler = proc_dowatchdog_thresh,
736 .extra1 = &neg_one,
737 .extra2 = &sixty,
740 .procname = "softlockup_panic",
741 .data = &softlockup_panic,
742 .maxlen = sizeof(int),
743 .mode = 0644,
744 .proc_handler = proc_dointvec_minmax,
745 .extra1 = &zero,
746 .extra2 = &one,
748 #endif
749 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR)
751 .procname = "unknown_nmi_panic",
752 .data = &unknown_nmi_panic,
753 .maxlen = sizeof (int),
754 .mode = 0644,
755 .proc_handler = proc_dointvec,
758 .procname = "nmi_watchdog",
759 .data = &nmi_watchdog_enabled,
760 .maxlen = sizeof (int),
761 .mode = 0644,
762 .proc_handler = proc_nmi_enabled,
764 #endif
765 #if defined(CONFIG_X86)
767 .procname = "panic_on_unrecovered_nmi",
768 .data = &panic_on_unrecovered_nmi,
769 .maxlen = sizeof(int),
770 .mode = 0644,
771 .proc_handler = proc_dointvec,
774 .procname = "panic_on_io_nmi",
775 .data = &panic_on_io_nmi,
776 .maxlen = sizeof(int),
777 .mode = 0644,
778 .proc_handler = proc_dointvec,
781 .procname = "bootloader_type",
782 .data = &bootloader_type,
783 .maxlen = sizeof (int),
784 .mode = 0444,
785 .proc_handler = proc_dointvec,
788 .procname = "bootloader_version",
789 .data = &bootloader_version,
790 .maxlen = sizeof (int),
791 .mode = 0444,
792 .proc_handler = proc_dointvec,
795 .procname = "kstack_depth_to_print",
796 .data = &kstack_depth_to_print,
797 .maxlen = sizeof(int),
798 .mode = 0644,
799 .proc_handler = proc_dointvec,
802 .procname = "io_delay_type",
803 .data = &io_delay_type,
804 .maxlen = sizeof(int),
805 .mode = 0644,
806 .proc_handler = proc_dointvec,
808 #endif
809 #if defined(CONFIG_MMU)
811 .procname = "randomize_va_space",
812 .data = &randomize_va_space,
813 .maxlen = sizeof(int),
814 .mode = 0644,
815 .proc_handler = proc_dointvec,
817 #endif
818 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
820 .procname = "spin_retry",
821 .data = &spin_retry,
822 .maxlen = sizeof (int),
823 .mode = 0644,
824 .proc_handler = proc_dointvec,
826 #endif
827 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
829 .procname = "acpi_video_flags",
830 .data = &acpi_realmode_flags,
831 .maxlen = sizeof (unsigned long),
832 .mode = 0644,
833 .proc_handler = proc_doulongvec_minmax,
835 #endif
836 #ifdef CONFIG_IA64
838 .procname = "ignore-unaligned-usertrap",
839 .data = &no_unaligned_warning,
840 .maxlen = sizeof (int),
841 .mode = 0644,
842 .proc_handler = proc_dointvec,
845 .procname = "unaligned-dump-stack",
846 .data = &unaligned_dump_stack,
847 .maxlen = sizeof (int),
848 .mode = 0644,
849 .proc_handler = proc_dointvec,
851 #endif
852 #ifdef CONFIG_DETECT_HUNG_TASK
854 .procname = "hung_task_panic",
855 .data = &sysctl_hung_task_panic,
856 .maxlen = sizeof(int),
857 .mode = 0644,
858 .proc_handler = proc_dointvec_minmax,
859 .extra1 = &zero,
860 .extra2 = &one,
863 .procname = "hung_task_check_count",
864 .data = &sysctl_hung_task_check_count,
865 .maxlen = sizeof(unsigned long),
866 .mode = 0644,
867 .proc_handler = proc_doulongvec_minmax,
870 .procname = "hung_task_timeout_secs",
871 .data = &sysctl_hung_task_timeout_secs,
872 .maxlen = sizeof(unsigned long),
873 .mode = 0644,
874 .proc_handler = proc_dohung_task_timeout_secs,
877 .procname = "hung_task_warnings",
878 .data = &sysctl_hung_task_warnings,
879 .maxlen = sizeof(unsigned long),
880 .mode = 0644,
881 .proc_handler = proc_doulongvec_minmax,
883 #endif
884 #ifdef CONFIG_COMPAT
886 .procname = "compat-log",
887 .data = &compat_log,
888 .maxlen = sizeof (int),
889 .mode = 0644,
890 .proc_handler = proc_dointvec,
892 #endif
893 #ifdef CONFIG_RT_MUTEXES
895 .procname = "max_lock_depth",
896 .data = &max_lock_depth,
897 .maxlen = sizeof(int),
898 .mode = 0644,
899 .proc_handler = proc_dointvec,
901 #endif
903 .procname = "poweroff_cmd",
904 .data = &poweroff_cmd,
905 .maxlen = POWEROFF_CMD_PATH_LEN,
906 .mode = 0644,
907 .proc_handler = proc_dostring,
909 #ifdef CONFIG_KEYS
911 .procname = "keys",
912 .mode = 0555,
913 .child = key_sysctls,
915 #endif
916 #ifdef CONFIG_RCU_TORTURE_TEST
918 .procname = "rcutorture_runnable",
919 .data = &rcutorture_runnable,
920 .maxlen = sizeof(int),
921 .mode = 0644,
922 .proc_handler = proc_dointvec,
924 #endif
925 #ifdef CONFIG_PERF_EVENTS
927 .procname = "perf_event_paranoid",
928 .data = &sysctl_perf_event_paranoid,
929 .maxlen = sizeof(sysctl_perf_event_paranoid),
930 .mode = 0644,
931 .proc_handler = proc_dointvec,
934 .procname = "perf_event_mlock_kb",
935 .data = &sysctl_perf_event_mlock,
936 .maxlen = sizeof(sysctl_perf_event_mlock),
937 .mode = 0644,
938 .proc_handler = proc_dointvec,
941 .procname = "perf_event_max_sample_rate",
942 .data = &sysctl_perf_event_sample_rate,
943 .maxlen = sizeof(sysctl_perf_event_sample_rate),
944 .mode = 0644,
945 .proc_handler = proc_dointvec,
947 #endif
948 #ifdef CONFIG_KMEMCHECK
950 .procname = "kmemcheck",
951 .data = &kmemcheck_enabled,
952 .maxlen = sizeof(int),
953 .mode = 0644,
954 .proc_handler = proc_dointvec,
956 #endif
957 #ifdef CONFIG_BLOCK
959 .procname = "blk_iopoll",
960 .data = &blk_iopoll_enabled,
961 .maxlen = sizeof(int),
962 .mode = 0644,
963 .proc_handler = proc_dointvec,
965 #endif
967 * NOTE: do not add new entries to this table unless you have read
968 * Documentation/sysctl/ctl_unnumbered.txt
973 static struct ctl_table vm_table[] = {
975 .procname = "overcommit_memory",
976 .data = &sysctl_overcommit_memory,
977 .maxlen = sizeof(sysctl_overcommit_memory),
978 .mode = 0644,
979 .proc_handler = proc_dointvec,
982 .procname = "panic_on_oom",
983 .data = &sysctl_panic_on_oom,
984 .maxlen = sizeof(sysctl_panic_on_oom),
985 .mode = 0644,
986 .proc_handler = proc_dointvec,
989 .procname = "oom_kill_allocating_task",
990 .data = &sysctl_oom_kill_allocating_task,
991 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
992 .mode = 0644,
993 .proc_handler = proc_dointvec,
996 .procname = "oom_dump_tasks",
997 .data = &sysctl_oom_dump_tasks,
998 .maxlen = sizeof(sysctl_oom_dump_tasks),
999 .mode = 0644,
1000 .proc_handler = proc_dointvec,
1003 .procname = "overcommit_ratio",
1004 .data = &sysctl_overcommit_ratio,
1005 .maxlen = sizeof(sysctl_overcommit_ratio),
1006 .mode = 0644,
1007 .proc_handler = proc_dointvec,
1010 .procname = "page-cluster",
1011 .data = &page_cluster,
1012 .maxlen = sizeof(int),
1013 .mode = 0644,
1014 .proc_handler = proc_dointvec,
1017 .procname = "dirty_background_ratio",
1018 .data = &dirty_background_ratio,
1019 .maxlen = sizeof(dirty_background_ratio),
1020 .mode = 0644,
1021 .proc_handler = dirty_background_ratio_handler,
1022 .extra1 = &zero,
1023 .extra2 = &one_hundred,
1026 .procname = "dirty_background_bytes",
1027 .data = &dirty_background_bytes,
1028 .maxlen = sizeof(dirty_background_bytes),
1029 .mode = 0644,
1030 .proc_handler = dirty_background_bytes_handler,
1031 .extra1 = &one_ul,
1034 .procname = "dirty_ratio",
1035 .data = &vm_dirty_ratio,
1036 .maxlen = sizeof(vm_dirty_ratio),
1037 .mode = 0644,
1038 .proc_handler = dirty_ratio_handler,
1039 .extra1 = &zero,
1040 .extra2 = &one_hundred,
1043 .procname = "dirty_bytes",
1044 .data = &vm_dirty_bytes,
1045 .maxlen = sizeof(vm_dirty_bytes),
1046 .mode = 0644,
1047 .proc_handler = dirty_bytes_handler,
1048 .extra1 = &dirty_bytes_min,
1051 .procname = "dirty_writeback_centisecs",
1052 .data = &dirty_writeback_interval,
1053 .maxlen = sizeof(dirty_writeback_interval),
1054 .mode = 0644,
1055 .proc_handler = dirty_writeback_centisecs_handler,
1058 .procname = "dirty_expire_centisecs",
1059 .data = &dirty_expire_interval,
1060 .maxlen = sizeof(dirty_expire_interval),
1061 .mode = 0644,
1062 .proc_handler = proc_dointvec,
1065 .procname = "nr_pdflush_threads",
1066 .data = &nr_pdflush_threads,
1067 .maxlen = sizeof nr_pdflush_threads,
1068 .mode = 0444 /* read-only*/,
1069 .proc_handler = proc_dointvec,
1072 .procname = "swappiness",
1073 .data = &vm_swappiness,
1074 .maxlen = sizeof(vm_swappiness),
1075 .mode = 0644,
1076 .proc_handler = proc_dointvec_minmax,
1077 .extra1 = &zero,
1078 .extra2 = &one_hundred,
1080 #ifdef CONFIG_HUGETLB_PAGE
1082 .procname = "nr_hugepages",
1083 .data = NULL,
1084 .maxlen = sizeof(unsigned long),
1085 .mode = 0644,
1086 .proc_handler = hugetlb_sysctl_handler,
1087 .extra1 = (void *)&hugetlb_zero,
1088 .extra2 = (void *)&hugetlb_infinity,
1090 #ifdef CONFIG_NUMA
1092 .procname = "nr_hugepages_mempolicy",
1093 .data = NULL,
1094 .maxlen = sizeof(unsigned long),
1095 .mode = 0644,
1096 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1097 .extra1 = (void *)&hugetlb_zero,
1098 .extra2 = (void *)&hugetlb_infinity,
1100 #endif
1102 .procname = "hugetlb_shm_group",
1103 .data = &sysctl_hugetlb_shm_group,
1104 .maxlen = sizeof(gid_t),
1105 .mode = 0644,
1106 .proc_handler = proc_dointvec,
1109 .procname = "hugepages_treat_as_movable",
1110 .data = &hugepages_treat_as_movable,
1111 .maxlen = sizeof(int),
1112 .mode = 0644,
1113 .proc_handler = hugetlb_treat_movable_handler,
1116 .procname = "nr_overcommit_hugepages",
1117 .data = NULL,
1118 .maxlen = sizeof(unsigned long),
1119 .mode = 0644,
1120 .proc_handler = hugetlb_overcommit_handler,
1121 .extra1 = (void *)&hugetlb_zero,
1122 .extra2 = (void *)&hugetlb_infinity,
1124 #endif
1126 .procname = "lowmem_reserve_ratio",
1127 .data = &sysctl_lowmem_reserve_ratio,
1128 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1129 .mode = 0644,
1130 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1133 .procname = "drop_caches",
1134 .data = &sysctl_drop_caches,
1135 .maxlen = sizeof(int),
1136 .mode = 0644,
1137 .proc_handler = drop_caches_sysctl_handler,
1139 #ifdef CONFIG_COMPACTION
1141 .procname = "compact_memory",
1142 .data = &sysctl_compact_memory,
1143 .maxlen = sizeof(int),
1144 .mode = 0200,
1145 .proc_handler = sysctl_compaction_handler,
1148 .procname = "extfrag_threshold",
1149 .data = &sysctl_extfrag_threshold,
1150 .maxlen = sizeof(int),
1151 .mode = 0644,
1152 .proc_handler = sysctl_extfrag_handler,
1153 .extra1 = &min_extfrag_threshold,
1154 .extra2 = &max_extfrag_threshold,
1157 #endif /* CONFIG_COMPACTION */
1159 .procname = "min_free_kbytes",
1160 .data = &min_free_kbytes,
1161 .maxlen = sizeof(min_free_kbytes),
1162 .mode = 0644,
1163 .proc_handler = min_free_kbytes_sysctl_handler,
1164 .extra1 = &zero,
1167 .procname = "percpu_pagelist_fraction",
1168 .data = &percpu_pagelist_fraction,
1169 .maxlen = sizeof(percpu_pagelist_fraction),
1170 .mode = 0644,
1171 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1172 .extra1 = &min_percpu_pagelist_fract,
1174 #ifdef CONFIG_MMU
1176 .procname = "max_map_count",
1177 .data = &sysctl_max_map_count,
1178 .maxlen = sizeof(sysctl_max_map_count),
1179 .mode = 0644,
1180 .proc_handler = proc_dointvec_minmax,
1181 .extra1 = &zero,
1183 #else
1185 .procname = "nr_trim_pages",
1186 .data = &sysctl_nr_trim_pages,
1187 .maxlen = sizeof(sysctl_nr_trim_pages),
1188 .mode = 0644,
1189 .proc_handler = proc_dointvec_minmax,
1190 .extra1 = &zero,
1192 #endif
1194 .procname = "laptop_mode",
1195 .data = &laptop_mode,
1196 .maxlen = sizeof(laptop_mode),
1197 .mode = 0644,
1198 .proc_handler = proc_dointvec_jiffies,
1201 .procname = "block_dump",
1202 .data = &block_dump,
1203 .maxlen = sizeof(block_dump),
1204 .mode = 0644,
1205 .proc_handler = proc_dointvec,
1206 .extra1 = &zero,
1209 .procname = "vfs_cache_pressure",
1210 .data = &sysctl_vfs_cache_pressure,
1211 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1212 .mode = 0644,
1213 .proc_handler = proc_dointvec,
1214 .extra1 = &zero,
1216 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1218 .procname = "legacy_va_layout",
1219 .data = &sysctl_legacy_va_layout,
1220 .maxlen = sizeof(sysctl_legacy_va_layout),
1221 .mode = 0644,
1222 .proc_handler = proc_dointvec,
1223 .extra1 = &zero,
1225 #endif
1226 #ifdef CONFIG_NUMA
1228 .procname = "zone_reclaim_mode",
1229 .data = &zone_reclaim_mode,
1230 .maxlen = sizeof(zone_reclaim_mode),
1231 .mode = 0644,
1232 .proc_handler = proc_dointvec,
1233 .extra1 = &zero,
1236 .procname = "min_unmapped_ratio",
1237 .data = &sysctl_min_unmapped_ratio,
1238 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1239 .mode = 0644,
1240 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1241 .extra1 = &zero,
1242 .extra2 = &one_hundred,
1245 .procname = "min_slab_ratio",
1246 .data = &sysctl_min_slab_ratio,
1247 .maxlen = sizeof(sysctl_min_slab_ratio),
1248 .mode = 0644,
1249 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1250 .extra1 = &zero,
1251 .extra2 = &one_hundred,
1253 #endif
1254 #ifdef CONFIG_SMP
1256 .procname = "stat_interval",
1257 .data = &sysctl_stat_interval,
1258 .maxlen = sizeof(sysctl_stat_interval),
1259 .mode = 0644,
1260 .proc_handler = proc_dointvec_jiffies,
1262 #endif
1263 #ifdef CONFIG_MMU
1265 .procname = "mmap_min_addr",
1266 .data = &dac_mmap_min_addr,
1267 .maxlen = sizeof(unsigned long),
1268 .mode = 0644,
1269 .proc_handler = mmap_min_addr_handler,
1271 #endif
1272 #ifdef CONFIG_NUMA
1274 .procname = "numa_zonelist_order",
1275 .data = &numa_zonelist_order,
1276 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1277 .mode = 0644,
1278 .proc_handler = numa_zonelist_order_handler,
1280 #endif
1281 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1282 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1284 .procname = "vdso_enabled",
1285 .data = &vdso_enabled,
1286 .maxlen = sizeof(vdso_enabled),
1287 .mode = 0644,
1288 .proc_handler = proc_dointvec,
1289 .extra1 = &zero,
1291 #endif
1292 #ifdef CONFIG_HIGHMEM
1294 .procname = "highmem_is_dirtyable",
1295 .data = &vm_highmem_is_dirtyable,
1296 .maxlen = sizeof(vm_highmem_is_dirtyable),
1297 .mode = 0644,
1298 .proc_handler = proc_dointvec_minmax,
1299 .extra1 = &zero,
1300 .extra2 = &one,
1302 #endif
1304 .procname = "scan_unevictable_pages",
1305 .data = &scan_unevictable_pages,
1306 .maxlen = sizeof(scan_unevictable_pages),
1307 .mode = 0644,
1308 .proc_handler = scan_unevictable_handler,
1310 #ifdef CONFIG_MEMORY_FAILURE
1312 .procname = "memory_failure_early_kill",
1313 .data = &sysctl_memory_failure_early_kill,
1314 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1315 .mode = 0644,
1316 .proc_handler = proc_dointvec_minmax,
1317 .extra1 = &zero,
1318 .extra2 = &one,
1321 .procname = "memory_failure_recovery",
1322 .data = &sysctl_memory_failure_recovery,
1323 .maxlen = sizeof(sysctl_memory_failure_recovery),
1324 .mode = 0644,
1325 .proc_handler = proc_dointvec_minmax,
1326 .extra1 = &zero,
1327 .extra2 = &one,
1329 #endif
1332 * NOTE: do not add new entries to this table unless you have read
1333 * Documentation/sysctl/ctl_unnumbered.txt
1338 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1339 static struct ctl_table binfmt_misc_table[] = {
1342 #endif
1344 static struct ctl_table fs_table[] = {
1346 .procname = "inode-nr",
1347 .data = &inodes_stat,
1348 .maxlen = 2*sizeof(int),
1349 .mode = 0444,
1350 .proc_handler = proc_nr_inodes,
1353 .procname = "inode-state",
1354 .data = &inodes_stat,
1355 .maxlen = 7*sizeof(int),
1356 .mode = 0444,
1357 .proc_handler = proc_nr_inodes,
1360 .procname = "file-nr",
1361 .data = &files_stat,
1362 .maxlen = sizeof(files_stat),
1363 .mode = 0444,
1364 .proc_handler = proc_nr_files,
1367 .procname = "file-max",
1368 .data = &files_stat.max_files,
1369 .maxlen = sizeof(files_stat.max_files),
1370 .mode = 0644,
1371 .proc_handler = proc_doulongvec_minmax,
1374 .procname = "nr_open",
1375 .data = &sysctl_nr_open,
1376 .maxlen = sizeof(int),
1377 .mode = 0644,
1378 .proc_handler = proc_dointvec_minmax,
1379 .extra1 = &sysctl_nr_open_min,
1380 .extra2 = &sysctl_nr_open_max,
1383 .procname = "dentry-state",
1384 .data = &dentry_stat,
1385 .maxlen = 6*sizeof(int),
1386 .mode = 0444,
1387 .proc_handler = proc_nr_dentry,
1390 .procname = "overflowuid",
1391 .data = &fs_overflowuid,
1392 .maxlen = sizeof(int),
1393 .mode = 0644,
1394 .proc_handler = proc_dointvec_minmax,
1395 .extra1 = &minolduid,
1396 .extra2 = &maxolduid,
1399 .procname = "overflowgid",
1400 .data = &fs_overflowgid,
1401 .maxlen = sizeof(int),
1402 .mode = 0644,
1403 .proc_handler = proc_dointvec_minmax,
1404 .extra1 = &minolduid,
1405 .extra2 = &maxolduid,
1407 #ifdef CONFIG_FILE_LOCKING
1409 .procname = "leases-enable",
1410 .data = &leases_enable,
1411 .maxlen = sizeof(int),
1412 .mode = 0644,
1413 .proc_handler = proc_dointvec,
1415 #endif
1416 #ifdef CONFIG_DNOTIFY
1418 .procname = "dir-notify-enable",
1419 .data = &dir_notify_enable,
1420 .maxlen = sizeof(int),
1421 .mode = 0644,
1422 .proc_handler = proc_dointvec,
1424 #endif
1425 #ifdef CONFIG_MMU
1426 #ifdef CONFIG_FILE_LOCKING
1428 .procname = "lease-break-time",
1429 .data = &lease_break_time,
1430 .maxlen = sizeof(int),
1431 .mode = 0644,
1432 .proc_handler = proc_dointvec,
1434 #endif
1435 #ifdef CONFIG_AIO
1437 .procname = "aio-nr",
1438 .data = &aio_nr,
1439 .maxlen = sizeof(aio_nr),
1440 .mode = 0444,
1441 .proc_handler = proc_doulongvec_minmax,
1444 .procname = "aio-max-nr",
1445 .data = &aio_max_nr,
1446 .maxlen = sizeof(aio_max_nr),
1447 .mode = 0644,
1448 .proc_handler = proc_doulongvec_minmax,
1450 #endif /* CONFIG_AIO */
1451 #ifdef CONFIG_INOTIFY_USER
1453 .procname = "inotify",
1454 .mode = 0555,
1455 .child = inotify_table,
1457 #endif
1458 #ifdef CONFIG_EPOLL
1460 .procname = "epoll",
1461 .mode = 0555,
1462 .child = epoll_table,
1464 #endif
1465 #endif
1467 .procname = "suid_dumpable",
1468 .data = &suid_dumpable,
1469 .maxlen = sizeof(int),
1470 .mode = 0644,
1471 .proc_handler = proc_dointvec_minmax,
1472 .extra1 = &zero,
1473 .extra2 = &two,
1475 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1477 .procname = "binfmt_misc",
1478 .mode = 0555,
1479 .child = binfmt_misc_table,
1481 #endif
1483 .procname = "pipe-max-size",
1484 .data = &pipe_max_size,
1485 .maxlen = sizeof(int),
1486 .mode = 0644,
1487 .proc_handler = &pipe_proc_fn,
1488 .extra1 = &pipe_min_size,
1491 * NOTE: do not add new entries to this table unless you have read
1492 * Documentation/sysctl/ctl_unnumbered.txt
1497 static struct ctl_table debug_table[] = {
1498 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1499 defined(CONFIG_S390)
1501 .procname = "exception-trace",
1502 .data = &show_unhandled_signals,
1503 .maxlen = sizeof(int),
1504 .mode = 0644,
1505 .proc_handler = proc_dointvec
1507 #endif
1508 #if defined(CONFIG_OPTPROBES)
1510 .procname = "kprobes-optimization",
1511 .data = &sysctl_kprobes_optimization,
1512 .maxlen = sizeof(int),
1513 .mode = 0644,
1514 .proc_handler = proc_kprobes_optimization_handler,
1515 .extra1 = &zero,
1516 .extra2 = &one,
1518 #endif
1522 static struct ctl_table dev_table[] = {
1526 static DEFINE_SPINLOCK(sysctl_lock);
1528 /* called under sysctl_lock */
1529 static int use_table(struct ctl_table_header *p)
1531 if (unlikely(p->unregistering))
1532 return 0;
1533 p->used++;
1534 return 1;
1537 /* called under sysctl_lock */
1538 static void unuse_table(struct ctl_table_header *p)
1540 if (!--p->used)
1541 if (unlikely(p->unregistering))
1542 complete(p->unregistering);
1545 /* called under sysctl_lock, will reacquire if has to wait */
1546 static void start_unregistering(struct ctl_table_header *p)
1549 * if p->used is 0, nobody will ever touch that entry again;
1550 * we'll eliminate all paths to it before dropping sysctl_lock
1552 if (unlikely(p->used)) {
1553 struct completion wait;
1554 init_completion(&wait);
1555 p->unregistering = &wait;
1556 spin_unlock(&sysctl_lock);
1557 wait_for_completion(&wait);
1558 spin_lock(&sysctl_lock);
1559 } else {
1560 /* anything non-NULL; we'll never dereference it */
1561 p->unregistering = ERR_PTR(-EINVAL);
1564 * do not remove from the list until nobody holds it; walking the
1565 * list in do_sysctl() relies on that.
1567 list_del_init(&p->ctl_entry);
1570 void sysctl_head_get(struct ctl_table_header *head)
1572 spin_lock(&sysctl_lock);
1573 head->count++;
1574 spin_unlock(&sysctl_lock);
1577 void sysctl_head_put(struct ctl_table_header *head)
1579 spin_lock(&sysctl_lock);
1580 if (!--head->count)
1581 kfree(head);
1582 spin_unlock(&sysctl_lock);
1585 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1587 if (!head)
1588 BUG();
1589 spin_lock(&sysctl_lock);
1590 if (!use_table(head))
1591 head = ERR_PTR(-ENOENT);
1592 spin_unlock(&sysctl_lock);
1593 return head;
1596 void sysctl_head_finish(struct ctl_table_header *head)
1598 if (!head)
1599 return;
1600 spin_lock(&sysctl_lock);
1601 unuse_table(head);
1602 spin_unlock(&sysctl_lock);
1605 static struct ctl_table_set *
1606 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1608 struct ctl_table_set *set = &root->default_set;
1609 if (root->lookup)
1610 set = root->lookup(root, namespaces);
1611 return set;
1614 static struct list_head *
1615 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1617 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1618 return &set->list;
1621 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1622 struct ctl_table_header *prev)
1624 struct ctl_table_root *root;
1625 struct list_head *header_list;
1626 struct ctl_table_header *head;
1627 struct list_head *tmp;
1629 spin_lock(&sysctl_lock);
1630 if (prev) {
1631 head = prev;
1632 tmp = &prev->ctl_entry;
1633 unuse_table(prev);
1634 goto next;
1636 tmp = &root_table_header.ctl_entry;
1637 for (;;) {
1638 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1640 if (!use_table(head))
1641 goto next;
1642 spin_unlock(&sysctl_lock);
1643 return head;
1644 next:
1645 root = head->root;
1646 tmp = tmp->next;
1647 header_list = lookup_header_list(root, namespaces);
1648 if (tmp != header_list)
1649 continue;
1651 do {
1652 root = list_entry(root->root_list.next,
1653 struct ctl_table_root, root_list);
1654 if (root == &sysctl_table_root)
1655 goto out;
1656 header_list = lookup_header_list(root, namespaces);
1657 } while (list_empty(header_list));
1658 tmp = header_list->next;
1660 out:
1661 spin_unlock(&sysctl_lock);
1662 return NULL;
1665 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1667 return __sysctl_head_next(current->nsproxy, prev);
1670 void register_sysctl_root(struct ctl_table_root *root)
1672 spin_lock(&sysctl_lock);
1673 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1674 spin_unlock(&sysctl_lock);
1678 * sysctl_perm does NOT grant the superuser all rights automatically, because
1679 * some sysctl variables are readonly even to root.
1682 static int test_perm(int mode, int op)
1684 if (!current_euid())
1685 mode >>= 6;
1686 else if (in_egroup_p(0))
1687 mode >>= 3;
1688 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1689 return 0;
1690 return -EACCES;
1693 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1695 int error;
1696 int mode;
1698 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1699 if (error)
1700 return error;
1702 if (root->permissions)
1703 mode = root->permissions(root, current->nsproxy, table);
1704 else
1705 mode = table->mode;
1707 return test_perm(mode, op);
1710 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1712 for (; table->procname; table++) {
1713 table->parent = parent;
1714 if (table->child)
1715 sysctl_set_parent(table, table->child);
1719 static __init int sysctl_init(void)
1721 sysctl_set_parent(NULL, root_table);
1722 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1723 sysctl_check_table(current->nsproxy, root_table);
1724 #endif
1725 return 0;
1728 core_initcall(sysctl_init);
1730 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1731 struct ctl_table *table)
1733 struct ctl_table *p;
1734 const char *s = branch->procname;
1736 /* branch should have named subdirectory as its first element */
1737 if (!s || !branch->child)
1738 return NULL;
1740 /* ... and nothing else */
1741 if (branch[1].procname)
1742 return NULL;
1744 /* table should contain subdirectory with the same name */
1745 for (p = table; p->procname; p++) {
1746 if (!p->child)
1747 continue;
1748 if (p->procname && strcmp(p->procname, s) == 0)
1749 return p;
1751 return NULL;
1754 /* see if attaching q to p would be an improvement */
1755 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1757 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1758 struct ctl_table *next;
1759 int is_better = 0;
1760 int not_in_parent = !p->attached_by;
1762 while ((next = is_branch_in(by, to)) != NULL) {
1763 if (by == q->attached_by)
1764 is_better = 1;
1765 if (to == p->attached_by)
1766 not_in_parent = 1;
1767 by = by->child;
1768 to = next->child;
1771 if (is_better && not_in_parent) {
1772 q->attached_by = by;
1773 q->attached_to = to;
1774 q->parent = p;
1779 * __register_sysctl_paths - register a sysctl hierarchy
1780 * @root: List of sysctl headers to register on
1781 * @namespaces: Data to compute which lists of sysctl entries are visible
1782 * @path: The path to the directory the sysctl table is in.
1783 * @table: the top-level table structure
1785 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1786 * array. A completely 0 filled entry terminates the table.
1788 * The members of the &struct ctl_table structure are used as follows:
1790 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1791 * enter a sysctl file
1793 * data - a pointer to data for use by proc_handler
1795 * maxlen - the maximum size in bytes of the data
1797 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1799 * child - a pointer to the child sysctl table if this entry is a directory, or
1800 * %NULL.
1802 * proc_handler - the text handler routine (described below)
1804 * de - for internal use by the sysctl routines
1806 * extra1, extra2 - extra pointers usable by the proc handler routines
1808 * Leaf nodes in the sysctl tree will be represented by a single file
1809 * under /proc; non-leaf nodes will be represented by directories.
1811 * sysctl(2) can automatically manage read and write requests through
1812 * the sysctl table. The data and maxlen fields of the ctl_table
1813 * struct enable minimal validation of the values being written to be
1814 * performed, and the mode field allows minimal authentication.
1816 * There must be a proc_handler routine for any terminal nodes
1817 * mirrored under /proc/sys (non-terminals are handled by a built-in
1818 * directory handler). Several default handlers are available to
1819 * cover common cases -
1821 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1822 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1823 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1825 * It is the handler's job to read the input buffer from user memory
1826 * and process it. The handler should return 0 on success.
1828 * This routine returns %NULL on a failure to register, and a pointer
1829 * to the table header on success.
1831 struct ctl_table_header *__register_sysctl_paths(
1832 struct ctl_table_root *root,
1833 struct nsproxy *namespaces,
1834 const struct ctl_path *path, struct ctl_table *table)
1836 struct ctl_table_header *header;
1837 struct ctl_table *new, **prevp;
1838 unsigned int n, npath;
1839 struct ctl_table_set *set;
1841 /* Count the path components */
1842 for (npath = 0; path[npath].procname; ++npath)
1846 * For each path component, allocate a 2-element ctl_table array.
1847 * The first array element will be filled with the sysctl entry
1848 * for this, the second will be the sentinel (procname == 0).
1850 * We allocate everything in one go so that we don't have to
1851 * worry about freeing additional memory in unregister_sysctl_table.
1853 header = kzalloc(sizeof(struct ctl_table_header) +
1854 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1855 if (!header)
1856 return NULL;
1858 new = (struct ctl_table *) (header + 1);
1860 /* Now connect the dots */
1861 prevp = &header->ctl_table;
1862 for (n = 0; n < npath; ++n, ++path) {
1863 /* Copy the procname */
1864 new->procname = path->procname;
1865 new->mode = 0555;
1867 *prevp = new;
1868 prevp = &new->child;
1870 new += 2;
1872 *prevp = table;
1873 header->ctl_table_arg = table;
1875 INIT_LIST_HEAD(&header->ctl_entry);
1876 header->used = 0;
1877 header->unregistering = NULL;
1878 header->root = root;
1879 sysctl_set_parent(NULL, header->ctl_table);
1880 header->count = 1;
1881 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1882 if (sysctl_check_table(namespaces, header->ctl_table)) {
1883 kfree(header);
1884 return NULL;
1886 #endif
1887 spin_lock(&sysctl_lock);
1888 header->set = lookup_header_set(root, namespaces);
1889 header->attached_by = header->ctl_table;
1890 header->attached_to = root_table;
1891 header->parent = &root_table_header;
1892 for (set = header->set; set; set = set->parent) {
1893 struct ctl_table_header *p;
1894 list_for_each_entry(p, &set->list, ctl_entry) {
1895 if (p->unregistering)
1896 continue;
1897 try_attach(p, header);
1900 header->parent->count++;
1901 list_add_tail(&header->ctl_entry, &header->set->list);
1902 spin_unlock(&sysctl_lock);
1904 return header;
1908 * register_sysctl_table_path - register a sysctl table hierarchy
1909 * @path: The path to the directory the sysctl table is in.
1910 * @table: the top-level table structure
1912 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1913 * array. A completely 0 filled entry terminates the table.
1915 * See __register_sysctl_paths for more details.
1917 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1918 struct ctl_table *table)
1920 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1921 path, table);
1925 * register_sysctl_table - register a sysctl table hierarchy
1926 * @table: the top-level table structure
1928 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1929 * array. A completely 0 filled entry terminates the table.
1931 * See register_sysctl_paths for more details.
1933 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1935 static const struct ctl_path null_path[] = { {} };
1937 return register_sysctl_paths(null_path, table);
1941 * unregister_sysctl_table - unregister a sysctl table hierarchy
1942 * @header: the header returned from register_sysctl_table
1944 * Unregisters the sysctl table and all children. proc entries may not
1945 * actually be removed until they are no longer used by anyone.
1947 void unregister_sysctl_table(struct ctl_table_header * header)
1949 might_sleep();
1951 if (header == NULL)
1952 return;
1954 spin_lock(&sysctl_lock);
1955 start_unregistering(header);
1956 if (!--header->parent->count) {
1957 WARN_ON(1);
1958 kfree(header->parent);
1960 if (!--header->count)
1961 kfree(header);
1962 spin_unlock(&sysctl_lock);
1965 int sysctl_is_seen(struct ctl_table_header *p)
1967 struct ctl_table_set *set = p->set;
1968 int res;
1969 spin_lock(&sysctl_lock);
1970 if (p->unregistering)
1971 res = 0;
1972 else if (!set->is_seen)
1973 res = 1;
1974 else
1975 res = set->is_seen(set);
1976 spin_unlock(&sysctl_lock);
1977 return res;
1980 void setup_sysctl_set(struct ctl_table_set *p,
1981 struct ctl_table_set *parent,
1982 int (*is_seen)(struct ctl_table_set *))
1984 INIT_LIST_HEAD(&p->list);
1985 p->parent = parent ? parent : &sysctl_table_root.default_set;
1986 p->is_seen = is_seen;
1989 #else /* !CONFIG_SYSCTL */
1990 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1992 return NULL;
1995 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1996 struct ctl_table *table)
1998 return NULL;
2001 void unregister_sysctl_table(struct ctl_table_header * table)
2005 void setup_sysctl_set(struct ctl_table_set *p,
2006 struct ctl_table_set *parent,
2007 int (*is_seen)(struct ctl_table_set *))
2011 void sysctl_head_put(struct ctl_table_header *head)
2015 #endif /* CONFIG_SYSCTL */
2018 * /proc/sys support
2021 #ifdef CONFIG_PROC_SYSCTL
2023 static int _proc_do_string(void* data, int maxlen, int write,
2024 void __user *buffer,
2025 size_t *lenp, loff_t *ppos)
2027 size_t len;
2028 char __user *p;
2029 char c;
2031 if (!data || !maxlen || !*lenp) {
2032 *lenp = 0;
2033 return 0;
2036 if (write) {
2037 len = 0;
2038 p = buffer;
2039 while (len < *lenp) {
2040 if (get_user(c, p++))
2041 return -EFAULT;
2042 if (c == 0 || c == '\n')
2043 break;
2044 len++;
2046 if (len >= maxlen)
2047 len = maxlen-1;
2048 if(copy_from_user(data, buffer, len))
2049 return -EFAULT;
2050 ((char *) data)[len] = 0;
2051 *ppos += *lenp;
2052 } else {
2053 len = strlen(data);
2054 if (len > maxlen)
2055 len = maxlen;
2057 if (*ppos > len) {
2058 *lenp = 0;
2059 return 0;
2062 data += *ppos;
2063 len -= *ppos;
2065 if (len > *lenp)
2066 len = *lenp;
2067 if (len)
2068 if(copy_to_user(buffer, data, len))
2069 return -EFAULT;
2070 if (len < *lenp) {
2071 if(put_user('\n', ((char __user *) buffer) + len))
2072 return -EFAULT;
2073 len++;
2075 *lenp = len;
2076 *ppos += len;
2078 return 0;
2082 * proc_dostring - read a string sysctl
2083 * @table: the sysctl table
2084 * @write: %TRUE if this is a write to the sysctl file
2085 * @buffer: the user buffer
2086 * @lenp: the size of the user buffer
2087 * @ppos: file position
2089 * Reads/writes a string from/to the user buffer. If the kernel
2090 * buffer provided is not large enough to hold the string, the
2091 * string is truncated. The copied string is %NULL-terminated.
2092 * If the string is being read by the user process, it is copied
2093 * and a newline '\n' is added. It is truncated if the buffer is
2094 * not large enough.
2096 * Returns 0 on success.
2098 int proc_dostring(struct ctl_table *table, int write,
2099 void __user *buffer, size_t *lenp, loff_t *ppos)
2101 return _proc_do_string(table->data, table->maxlen, write,
2102 buffer, lenp, ppos);
2105 static size_t proc_skip_spaces(char **buf)
2107 size_t ret;
2108 char *tmp = skip_spaces(*buf);
2109 ret = tmp - *buf;
2110 *buf = tmp;
2111 return ret;
2114 static void proc_skip_char(char **buf, size_t *size, const char v)
2116 while (*size) {
2117 if (**buf != v)
2118 break;
2119 (*size)--;
2120 (*buf)++;
2124 #define TMPBUFLEN 22
2126 * proc_get_long - reads an ASCII formatted integer from a user buffer
2128 * @buf: a kernel buffer
2129 * @size: size of the kernel buffer
2130 * @val: this is where the number will be stored
2131 * @neg: set to %TRUE if number is negative
2132 * @perm_tr: a vector which contains the allowed trailers
2133 * @perm_tr_len: size of the perm_tr vector
2134 * @tr: pointer to store the trailer character
2136 * In case of success %0 is returned and @buf and @size are updated with
2137 * the amount of bytes read. If @tr is non-NULL and a trailing
2138 * character exists (size is non-zero after returning from this
2139 * function), @tr is updated with the trailing character.
2141 static int proc_get_long(char **buf, size_t *size,
2142 unsigned long *val, bool *neg,
2143 const char *perm_tr, unsigned perm_tr_len, char *tr)
2145 int len;
2146 char *p, tmp[TMPBUFLEN];
2148 if (!*size)
2149 return -EINVAL;
2151 len = *size;
2152 if (len > TMPBUFLEN - 1)
2153 len = TMPBUFLEN - 1;
2155 memcpy(tmp, *buf, len);
2157 tmp[len] = 0;
2158 p = tmp;
2159 if (*p == '-' && *size > 1) {
2160 *neg = true;
2161 p++;
2162 } else
2163 *neg = false;
2164 if (!isdigit(*p))
2165 return -EINVAL;
2167 *val = simple_strtoul(p, &p, 0);
2169 len = p - tmp;
2171 /* We don't know if the next char is whitespace thus we may accept
2172 * invalid integers (e.g. 1234...a) or two integers instead of one
2173 * (e.g. 123...1). So lets not allow such large numbers. */
2174 if (len == TMPBUFLEN - 1)
2175 return -EINVAL;
2177 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2178 return -EINVAL;
2180 if (tr && (len < *size))
2181 *tr = *p;
2183 *buf += len;
2184 *size -= len;
2186 return 0;
2190 * proc_put_long - converts an integer to a decimal ASCII formatted string
2192 * @buf: the user buffer
2193 * @size: the size of the user buffer
2194 * @val: the integer to be converted
2195 * @neg: sign of the number, %TRUE for negative
2197 * In case of success %0 is returned and @buf and @size are updated with
2198 * the amount of bytes written.
2200 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2201 bool neg)
2203 int len;
2204 char tmp[TMPBUFLEN], *p = tmp;
2206 sprintf(p, "%s%lu", neg ? "-" : "", val);
2207 len = strlen(tmp);
2208 if (len > *size)
2209 len = *size;
2210 if (copy_to_user(*buf, tmp, len))
2211 return -EFAULT;
2212 *size -= len;
2213 *buf += len;
2214 return 0;
2216 #undef TMPBUFLEN
2218 static int proc_put_char(void __user **buf, size_t *size, char c)
2220 if (*size) {
2221 char __user **buffer = (char __user **)buf;
2222 if (put_user(c, *buffer))
2223 return -EFAULT;
2224 (*size)--, (*buffer)++;
2225 *buf = *buffer;
2227 return 0;
2230 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2231 int *valp,
2232 int write, void *data)
2234 if (write) {
2235 *valp = *negp ? -*lvalp : *lvalp;
2236 } else {
2237 int val = *valp;
2238 if (val < 0) {
2239 *negp = true;
2240 *lvalp = (unsigned long)-val;
2241 } else {
2242 *negp = false;
2243 *lvalp = (unsigned long)val;
2246 return 0;
2249 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2251 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2252 int write, void __user *buffer,
2253 size_t *lenp, loff_t *ppos,
2254 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2255 int write, void *data),
2256 void *data)
2258 int *i, vleft, first = 1, err = 0;
2259 unsigned long page = 0;
2260 size_t left;
2261 char *kbuf;
2263 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2264 *lenp = 0;
2265 return 0;
2268 i = (int *) tbl_data;
2269 vleft = table->maxlen / sizeof(*i);
2270 left = *lenp;
2272 if (!conv)
2273 conv = do_proc_dointvec_conv;
2275 if (write) {
2276 if (left > PAGE_SIZE - 1)
2277 left = PAGE_SIZE - 1;
2278 page = __get_free_page(GFP_TEMPORARY);
2279 kbuf = (char *) page;
2280 if (!kbuf)
2281 return -ENOMEM;
2282 if (copy_from_user(kbuf, buffer, left)) {
2283 err = -EFAULT;
2284 goto free;
2286 kbuf[left] = 0;
2289 for (; left && vleft--; i++, first=0) {
2290 unsigned long lval;
2291 bool neg;
2293 if (write) {
2294 left -= proc_skip_spaces(&kbuf);
2296 if (!left)
2297 break;
2298 err = proc_get_long(&kbuf, &left, &lval, &neg,
2299 proc_wspace_sep,
2300 sizeof(proc_wspace_sep), NULL);
2301 if (err)
2302 break;
2303 if (conv(&neg, &lval, i, 1, data)) {
2304 err = -EINVAL;
2305 break;
2307 } else {
2308 if (conv(&neg, &lval, i, 0, data)) {
2309 err = -EINVAL;
2310 break;
2312 if (!first)
2313 err = proc_put_char(&buffer, &left, '\t');
2314 if (err)
2315 break;
2316 err = proc_put_long(&buffer, &left, lval, neg);
2317 if (err)
2318 break;
2322 if (!write && !first && left && !err)
2323 err = proc_put_char(&buffer, &left, '\n');
2324 if (write && !err && left)
2325 left -= proc_skip_spaces(&kbuf);
2326 free:
2327 if (write) {
2328 free_page(page);
2329 if (first)
2330 return err ? : -EINVAL;
2332 *lenp -= left;
2333 *ppos += *lenp;
2334 return err;
2337 static int do_proc_dointvec(struct ctl_table *table, int write,
2338 void __user *buffer, size_t *lenp, loff_t *ppos,
2339 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2340 int write, void *data),
2341 void *data)
2343 return __do_proc_dointvec(table->data, table, write,
2344 buffer, lenp, ppos, conv, data);
2348 * proc_dointvec - read a vector of integers
2349 * @table: the sysctl table
2350 * @write: %TRUE if this is a write to the sysctl file
2351 * @buffer: the user buffer
2352 * @lenp: the size of the user buffer
2353 * @ppos: file position
2355 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2356 * values from/to the user buffer, treated as an ASCII string.
2358 * Returns 0 on success.
2360 int proc_dointvec(struct ctl_table *table, int write,
2361 void __user *buffer, size_t *lenp, loff_t *ppos)
2363 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2364 NULL,NULL);
2368 * Taint values can only be increased
2369 * This means we can safely use a temporary.
2371 static int proc_taint(struct ctl_table *table, int write,
2372 void __user *buffer, size_t *lenp, loff_t *ppos)
2374 struct ctl_table t;
2375 unsigned long tmptaint = get_taint();
2376 int err;
2378 if (write && !capable(CAP_SYS_ADMIN))
2379 return -EPERM;
2381 t = *table;
2382 t.data = &tmptaint;
2383 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2384 if (err < 0)
2385 return err;
2387 if (write) {
2389 * Poor man's atomic or. Not worth adding a primitive
2390 * to everyone's atomic.h for this
2392 int i;
2393 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2394 if ((tmptaint >> i) & 1)
2395 add_taint(i);
2399 return err;
2402 struct do_proc_dointvec_minmax_conv_param {
2403 int *min;
2404 int *max;
2407 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2408 int *valp,
2409 int write, void *data)
2411 struct do_proc_dointvec_minmax_conv_param *param = data;
2412 if (write) {
2413 int val = *negp ? -*lvalp : *lvalp;
2414 if ((param->min && *param->min > val) ||
2415 (param->max && *param->max < val))
2416 return -EINVAL;
2417 *valp = val;
2418 } else {
2419 int val = *valp;
2420 if (val < 0) {
2421 *negp = true;
2422 *lvalp = (unsigned long)-val;
2423 } else {
2424 *negp = false;
2425 *lvalp = (unsigned long)val;
2428 return 0;
2432 * proc_dointvec_minmax - read a vector of integers with min/max values
2433 * @table: the sysctl table
2434 * @write: %TRUE if this is a write to the sysctl file
2435 * @buffer: the user buffer
2436 * @lenp: the size of the user buffer
2437 * @ppos: file position
2439 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2440 * values from/to the user buffer, treated as an ASCII string.
2442 * This routine will ensure the values are within the range specified by
2443 * table->extra1 (min) and table->extra2 (max).
2445 * Returns 0 on success.
2447 int proc_dointvec_minmax(struct ctl_table *table, int write,
2448 void __user *buffer, size_t *lenp, loff_t *ppos)
2450 struct do_proc_dointvec_minmax_conv_param param = {
2451 .min = (int *) table->extra1,
2452 .max = (int *) table->extra2,
2454 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2455 do_proc_dointvec_minmax_conv, &param);
2458 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2459 void __user *buffer,
2460 size_t *lenp, loff_t *ppos,
2461 unsigned long convmul,
2462 unsigned long convdiv)
2464 unsigned long *i, *min, *max;
2465 int vleft, first = 1, err = 0;
2466 unsigned long page = 0;
2467 size_t left;
2468 char *kbuf;
2470 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2471 *lenp = 0;
2472 return 0;
2475 i = (unsigned long *) data;
2476 min = (unsigned long *) table->extra1;
2477 max = (unsigned long *) table->extra2;
2478 vleft = table->maxlen / sizeof(unsigned long);
2479 left = *lenp;
2481 if (write) {
2482 if (left > PAGE_SIZE - 1)
2483 left = PAGE_SIZE - 1;
2484 page = __get_free_page(GFP_TEMPORARY);
2485 kbuf = (char *) page;
2486 if (!kbuf)
2487 return -ENOMEM;
2488 if (copy_from_user(kbuf, buffer, left)) {
2489 err = -EFAULT;
2490 goto free;
2492 kbuf[left] = 0;
2495 for (; left && vleft--; i++, first = 0) {
2496 unsigned long val;
2498 if (write) {
2499 bool neg;
2501 left -= proc_skip_spaces(&kbuf);
2503 err = proc_get_long(&kbuf, &left, &val, &neg,
2504 proc_wspace_sep,
2505 sizeof(proc_wspace_sep), NULL);
2506 if (err)
2507 break;
2508 if (neg)
2509 continue;
2510 if ((min && val < *min) || (max && val > *max))
2511 continue;
2512 *i = val;
2513 } else {
2514 val = convdiv * (*i) / convmul;
2515 if (!first)
2516 err = proc_put_char(&buffer, &left, '\t');
2517 err = proc_put_long(&buffer, &left, val, false);
2518 if (err)
2519 break;
2523 if (!write && !first && left && !err)
2524 err = proc_put_char(&buffer, &left, '\n');
2525 if (write && !err)
2526 left -= proc_skip_spaces(&kbuf);
2527 free:
2528 if (write) {
2529 free_page(page);
2530 if (first)
2531 return err ? : -EINVAL;
2533 *lenp -= left;
2534 *ppos += *lenp;
2535 return err;
2538 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2539 void __user *buffer,
2540 size_t *lenp, loff_t *ppos,
2541 unsigned long convmul,
2542 unsigned long convdiv)
2544 return __do_proc_doulongvec_minmax(table->data, table, write,
2545 buffer, lenp, ppos, convmul, convdiv);
2549 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2550 * @table: the sysctl table
2551 * @write: %TRUE if this is a write to the sysctl file
2552 * @buffer: the user buffer
2553 * @lenp: the size of the user buffer
2554 * @ppos: file position
2556 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2557 * values from/to the user buffer, treated as an ASCII string.
2559 * This routine will ensure the values are within the range specified by
2560 * table->extra1 (min) and table->extra2 (max).
2562 * Returns 0 on success.
2564 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2565 void __user *buffer, size_t *lenp, loff_t *ppos)
2567 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2571 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2572 * @table: the sysctl table
2573 * @write: %TRUE if this is a write to the sysctl file
2574 * @buffer: the user buffer
2575 * @lenp: the size of the user buffer
2576 * @ppos: file position
2578 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2579 * values from/to the user buffer, treated as an ASCII string. The values
2580 * are treated as milliseconds, and converted to jiffies when they are stored.
2582 * This routine will ensure the values are within the range specified by
2583 * table->extra1 (min) and table->extra2 (max).
2585 * Returns 0 on success.
2587 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2588 void __user *buffer,
2589 size_t *lenp, loff_t *ppos)
2591 return do_proc_doulongvec_minmax(table, write, buffer,
2592 lenp, ppos, HZ, 1000l);
2596 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2597 int *valp,
2598 int write, void *data)
2600 if (write) {
2601 if (*lvalp > LONG_MAX / HZ)
2602 return 1;
2603 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2604 } else {
2605 int val = *valp;
2606 unsigned long lval;
2607 if (val < 0) {
2608 *negp = true;
2609 lval = (unsigned long)-val;
2610 } else {
2611 *negp = false;
2612 lval = (unsigned long)val;
2614 *lvalp = lval / HZ;
2616 return 0;
2619 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2620 int *valp,
2621 int write, void *data)
2623 if (write) {
2624 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2625 return 1;
2626 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2627 } else {
2628 int val = *valp;
2629 unsigned long lval;
2630 if (val < 0) {
2631 *negp = true;
2632 lval = (unsigned long)-val;
2633 } else {
2634 *negp = false;
2635 lval = (unsigned long)val;
2637 *lvalp = jiffies_to_clock_t(lval);
2639 return 0;
2642 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2643 int *valp,
2644 int write, void *data)
2646 if (write) {
2647 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2648 } else {
2649 int val = *valp;
2650 unsigned long lval;
2651 if (val < 0) {
2652 *negp = true;
2653 lval = (unsigned long)-val;
2654 } else {
2655 *negp = false;
2656 lval = (unsigned long)val;
2658 *lvalp = jiffies_to_msecs(lval);
2660 return 0;
2664 * proc_dointvec_jiffies - read a vector of integers as seconds
2665 * @table: the sysctl table
2666 * @write: %TRUE if this is a write to the sysctl file
2667 * @buffer: the user buffer
2668 * @lenp: the size of the user buffer
2669 * @ppos: file position
2671 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2672 * values from/to the user buffer, treated as an ASCII string.
2673 * The values read are assumed to be in seconds, and are converted into
2674 * jiffies.
2676 * Returns 0 on success.
2678 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2679 void __user *buffer, size_t *lenp, loff_t *ppos)
2681 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2682 do_proc_dointvec_jiffies_conv,NULL);
2686 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2687 * @table: the sysctl table
2688 * @write: %TRUE if this is a write to the sysctl file
2689 * @buffer: the user buffer
2690 * @lenp: the size of the user buffer
2691 * @ppos: pointer to the file position
2693 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2694 * values from/to the user buffer, treated as an ASCII string.
2695 * The values read are assumed to be in 1/USER_HZ seconds, and
2696 * are converted into jiffies.
2698 * Returns 0 on success.
2700 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2701 void __user *buffer, size_t *lenp, loff_t *ppos)
2703 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2704 do_proc_dointvec_userhz_jiffies_conv,NULL);
2708 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2709 * @table: the sysctl table
2710 * @write: %TRUE if this is a write to the sysctl file
2711 * @buffer: the user buffer
2712 * @lenp: the size of the user buffer
2713 * @ppos: file position
2714 * @ppos: the current position in the file
2716 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2717 * values from/to the user buffer, treated as an ASCII string.
2718 * The values read are assumed to be in 1/1000 seconds, and
2719 * are converted into jiffies.
2721 * Returns 0 on success.
2723 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2724 void __user *buffer, size_t *lenp, loff_t *ppos)
2726 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2727 do_proc_dointvec_ms_jiffies_conv, NULL);
2730 static int proc_do_cad_pid(struct ctl_table *table, int write,
2731 void __user *buffer, size_t *lenp, loff_t *ppos)
2733 struct pid *new_pid;
2734 pid_t tmp;
2735 int r;
2737 tmp = pid_vnr(cad_pid);
2739 r = __do_proc_dointvec(&tmp, table, write, buffer,
2740 lenp, ppos, NULL, NULL);
2741 if (r || !write)
2742 return r;
2744 new_pid = find_get_pid(tmp);
2745 if (!new_pid)
2746 return -ESRCH;
2748 put_pid(xchg(&cad_pid, new_pid));
2749 return 0;
2753 * proc_do_large_bitmap - read/write from/to a large bitmap
2754 * @table: the sysctl table
2755 * @write: %TRUE if this is a write to the sysctl file
2756 * @buffer: the user buffer
2757 * @lenp: the size of the user buffer
2758 * @ppos: file position
2760 * The bitmap is stored at table->data and the bitmap length (in bits)
2761 * in table->maxlen.
2763 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2764 * large bitmaps may be represented in a compact manner. Writing into
2765 * the file will clear the bitmap then update it with the given input.
2767 * Returns 0 on success.
2769 int proc_do_large_bitmap(struct ctl_table *table, int write,
2770 void __user *buffer, size_t *lenp, loff_t *ppos)
2772 int err = 0;
2773 bool first = 1;
2774 size_t left = *lenp;
2775 unsigned long bitmap_len = table->maxlen;
2776 unsigned long *bitmap = (unsigned long *) table->data;
2777 unsigned long *tmp_bitmap = NULL;
2778 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2780 if (!bitmap_len || !left || (*ppos && !write)) {
2781 *lenp = 0;
2782 return 0;
2785 if (write) {
2786 unsigned long page = 0;
2787 char *kbuf;
2789 if (left > PAGE_SIZE - 1)
2790 left = PAGE_SIZE - 1;
2792 page = __get_free_page(GFP_TEMPORARY);
2793 kbuf = (char *) page;
2794 if (!kbuf)
2795 return -ENOMEM;
2796 if (copy_from_user(kbuf, buffer, left)) {
2797 free_page(page);
2798 return -EFAULT;
2800 kbuf[left] = 0;
2802 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2803 GFP_KERNEL);
2804 if (!tmp_bitmap) {
2805 free_page(page);
2806 return -ENOMEM;
2808 proc_skip_char(&kbuf, &left, '\n');
2809 while (!err && left) {
2810 unsigned long val_a, val_b;
2811 bool neg;
2813 err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2814 sizeof(tr_a), &c);
2815 if (err)
2816 break;
2817 if (val_a >= bitmap_len || neg) {
2818 err = -EINVAL;
2819 break;
2822 val_b = val_a;
2823 if (left) {
2824 kbuf++;
2825 left--;
2828 if (c == '-') {
2829 err = proc_get_long(&kbuf, &left, &val_b,
2830 &neg, tr_b, sizeof(tr_b),
2831 &c);
2832 if (err)
2833 break;
2834 if (val_b >= bitmap_len || neg ||
2835 val_a > val_b) {
2836 err = -EINVAL;
2837 break;
2839 if (left) {
2840 kbuf++;
2841 left--;
2845 while (val_a <= val_b)
2846 set_bit(val_a++, tmp_bitmap);
2848 first = 0;
2849 proc_skip_char(&kbuf, &left, '\n');
2851 free_page(page);
2852 } else {
2853 unsigned long bit_a, bit_b = 0;
2855 while (left) {
2856 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2857 if (bit_a >= bitmap_len)
2858 break;
2859 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2860 bit_a + 1) - 1;
2862 if (!first) {
2863 err = proc_put_char(&buffer, &left, ',');
2864 if (err)
2865 break;
2867 err = proc_put_long(&buffer, &left, bit_a, false);
2868 if (err)
2869 break;
2870 if (bit_a != bit_b) {
2871 err = proc_put_char(&buffer, &left, '-');
2872 if (err)
2873 break;
2874 err = proc_put_long(&buffer, &left, bit_b, false);
2875 if (err)
2876 break;
2879 first = 0; bit_b++;
2881 if (!err)
2882 err = proc_put_char(&buffer, &left, '\n');
2885 if (!err) {
2886 if (write) {
2887 if (*ppos)
2888 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2889 else
2890 memcpy(bitmap, tmp_bitmap,
2891 BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2893 kfree(tmp_bitmap);
2894 *lenp -= left;
2895 *ppos += *lenp;
2896 return 0;
2897 } else {
2898 kfree(tmp_bitmap);
2899 return err;
2903 #else /* CONFIG_PROC_FS */
2905 int proc_dostring(struct ctl_table *table, int write,
2906 void __user *buffer, size_t *lenp, loff_t *ppos)
2908 return -ENOSYS;
2911 int proc_dointvec(struct ctl_table *table, int write,
2912 void __user *buffer, size_t *lenp, loff_t *ppos)
2914 return -ENOSYS;
2917 int proc_dointvec_minmax(struct ctl_table *table, int write,
2918 void __user *buffer, size_t *lenp, loff_t *ppos)
2920 return -ENOSYS;
2923 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2924 void __user *buffer, size_t *lenp, loff_t *ppos)
2926 return -ENOSYS;
2929 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2930 void __user *buffer, size_t *lenp, loff_t *ppos)
2932 return -ENOSYS;
2935 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2936 void __user *buffer, size_t *lenp, loff_t *ppos)
2938 return -ENOSYS;
2941 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2942 void __user *buffer, size_t *lenp, loff_t *ppos)
2944 return -ENOSYS;
2947 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2948 void __user *buffer,
2949 size_t *lenp, loff_t *ppos)
2951 return -ENOSYS;
2955 #endif /* CONFIG_PROC_FS */
2958 * No sense putting this after each symbol definition, twice,
2959 * exception granted :-)
2961 EXPORT_SYMBOL(proc_dointvec);
2962 EXPORT_SYMBOL(proc_dointvec_jiffies);
2963 EXPORT_SYMBOL(proc_dointvec_minmax);
2964 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2965 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2966 EXPORT_SYMBOL(proc_dostring);
2967 EXPORT_SYMBOL(proc_doulongvec_minmax);
2968 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2969 EXPORT_SYMBOL(register_sysctl_table);
2970 EXPORT_SYMBOL(register_sysctl_paths);
2971 EXPORT_SYMBOL(unregister_sysctl_table);