isci: atomic device lookup and reference counting
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / sysctl.c
blob4fc92445a29c920405935176b473485af8140f17
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/printk.h>
28 #include <linux/proc_fs.h>
29 #include <linux/security.h>
30 #include <linux/ctype.h>
31 #include <linux/kmemcheck.h>
32 #include <linux/fs.h>
33 #include <linux/init.h>
34 #include <linux/kernel.h>
35 #include <linux/kobject.h>
36 #include <linux/net.h>
37 #include <linux/sysrq.h>
38 #include <linux/highuid.h>
39 #include <linux/writeback.h>
40 #include <linux/ratelimit.h>
41 #include <linux/compaction.h>
42 #include <linux/hugetlb.h>
43 #include <linux/initrd.h>
44 #include <linux/key.h>
45 #include <linux/times.h>
46 #include <linux/limits.h>
47 #include <linux/dcache.h>
48 #include <linux/dnotify.h>
49 #include <linux/syscalls.h>
50 #include <linux/vmstat.h>
51 #include <linux/nfs_fs.h>
52 #include <linux/acpi.h>
53 #include <linux/reboot.h>
54 #include <linux/ftrace.h>
55 #include <linux/perf_event.h>
56 #include <linux/kprobes.h>
57 #include <linux/pipe_fs_i.h>
58 #include <linux/oom.h>
59 #include <linux/kmod.h>
61 #include <asm/uaccess.h>
62 #include <asm/processor.h>
64 #ifdef CONFIG_X86
65 #include <asm/nmi.h>
66 #include <asm/stacktrace.h>
67 #include <asm/io.h>
68 #endif
69 #ifdef CONFIG_BSD_PROCESS_ACCT
70 #include <linux/acct.h>
71 #endif
72 #ifdef CONFIG_RT_MUTEXES
73 #include <linux/rtmutex.h>
74 #endif
75 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
76 #include <linux/lockdep.h>
77 #endif
78 #ifdef CONFIG_CHR_DEV_SG
79 #include <scsi/sg.h>
80 #endif
82 #ifdef CONFIG_LOCKUP_DETECTOR
83 #include <linux/nmi.h>
84 #endif
87 #if defined(CONFIG_SYSCTL)
89 /* External variables not in a header file. */
90 extern int sysctl_overcommit_memory;
91 extern int sysctl_overcommit_ratio;
92 extern int max_threads;
93 extern int core_uses_pid;
94 extern int suid_dumpable;
95 extern char core_pattern[];
96 extern unsigned int core_pipe_limit;
97 extern int pid_max;
98 extern int min_free_kbytes;
99 extern int pid_max_min, pid_max_max;
100 extern int sysctl_drop_caches;
101 extern int percpu_pagelist_fraction;
102 extern int compat_log;
103 extern int latencytop_enabled;
104 extern int sysctl_nr_open_min, sysctl_nr_open_max;
105 #ifndef CONFIG_MMU
106 extern int sysctl_nr_trim_pages;
107 #endif
108 #ifdef CONFIG_BLOCK
109 extern int blk_iopoll_enabled;
110 #endif
112 /* Constants used for minimum and maximum */
113 #ifdef CONFIG_LOCKUP_DETECTOR
114 static int sixty = 60;
115 static int neg_one = -1;
116 #endif
118 static int zero;
119 static int __maybe_unused one = 1;
120 static int __maybe_unused two = 2;
121 static int __maybe_unused three = 3;
122 static unsigned long one_ul = 1;
123 static int one_hundred = 100;
124 #ifdef CONFIG_PRINTK
125 static int ten_thousand = 10000;
126 #endif
128 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
129 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
131 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
132 static int maxolduid = 65535;
133 static int minolduid;
134 static int min_percpu_pagelist_fract = 8;
136 static int ngroups_max = NGROUPS_MAX;
138 #ifdef CONFIG_INOTIFY_USER
139 #include <linux/inotify.h>
140 #endif
141 #ifdef CONFIG_SPARC
142 #include <asm/system.h>
143 #endif
145 #ifdef CONFIG_SPARC64
146 extern int sysctl_tsb_ratio;
147 #endif
149 #ifdef __hppa__
150 extern int pwrsw_enabled;
151 extern int unaligned_enabled;
152 #endif
154 #ifdef CONFIG_S390
155 #ifdef CONFIG_MATHEMU
156 extern int sysctl_ieee_emulation_warnings;
157 #endif
158 extern int sysctl_userprocess_debug;
159 extern int spin_retry;
160 #endif
162 #ifdef CONFIG_IA64
163 extern int no_unaligned_warning;
164 extern int unaligned_dump_stack;
165 #endif
167 #ifdef CONFIG_PROC_SYSCTL
168 static int proc_do_cad_pid(struct ctl_table *table, int write,
169 void __user *buffer, size_t *lenp, loff_t *ppos);
170 static int proc_taint(struct ctl_table *table, int write,
171 void __user *buffer, size_t *lenp, loff_t *ppos);
172 #endif
174 #ifdef CONFIG_PRINTK
175 static int proc_dmesg_restrict(struct ctl_table *table, int write,
176 void __user *buffer, size_t *lenp, loff_t *ppos);
177 #endif
179 #ifdef CONFIG_MAGIC_SYSRQ
180 /* Note: sysrq code uses it's own private copy */
181 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
183 static int sysrq_sysctl_handler(ctl_table *table, int write,
184 void __user *buffer, size_t *lenp,
185 loff_t *ppos)
187 int error;
189 error = proc_dointvec(table, write, buffer, lenp, ppos);
190 if (error)
191 return error;
193 if (write)
194 sysrq_toggle_support(__sysrq_enabled);
196 return 0;
199 #endif
201 static struct ctl_table root_table[];
202 static struct ctl_table_root sysctl_table_root;
203 static struct ctl_table_header root_table_header = {
204 {{.count = 1,
205 .ctl_table = root_table,
206 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
207 .root = &sysctl_table_root,
208 .set = &sysctl_table_root.default_set,
210 static struct ctl_table_root sysctl_table_root = {
211 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
212 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
215 static struct ctl_table kern_table[];
216 static struct ctl_table vm_table[];
217 static struct ctl_table fs_table[];
218 static struct ctl_table debug_table[];
219 static struct ctl_table dev_table[];
220 extern struct ctl_table random_table[];
221 #ifdef CONFIG_EPOLL
222 extern struct ctl_table epoll_table[];
223 #endif
225 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
226 int sysctl_legacy_va_layout;
227 #endif
229 /* The default sysctl tables: */
231 static struct ctl_table root_table[] = {
233 .procname = "kernel",
234 .mode = 0555,
235 .child = kern_table,
238 .procname = "vm",
239 .mode = 0555,
240 .child = vm_table,
243 .procname = "fs",
244 .mode = 0555,
245 .child = fs_table,
248 .procname = "debug",
249 .mode = 0555,
250 .child = debug_table,
253 .procname = "dev",
254 .mode = 0555,
255 .child = dev_table,
260 #ifdef CONFIG_SCHED_DEBUG
261 static int min_sched_granularity_ns = 100000; /* 100 usecs */
262 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
263 static int min_wakeup_granularity_ns; /* 0 usecs */
264 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
265 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
266 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
267 #endif
269 #ifdef CONFIG_COMPACTION
270 static int min_extfrag_threshold;
271 static int max_extfrag_threshold = 1000;
272 #endif
274 static struct ctl_table kern_table[] = {
276 .procname = "sched_child_runs_first",
277 .data = &sysctl_sched_child_runs_first,
278 .maxlen = sizeof(unsigned int),
279 .mode = 0644,
280 .proc_handler = proc_dointvec,
282 #ifdef CONFIG_SCHED_DEBUG
284 .procname = "sched_min_granularity_ns",
285 .data = &sysctl_sched_min_granularity,
286 .maxlen = sizeof(unsigned int),
287 .mode = 0644,
288 .proc_handler = sched_proc_update_handler,
289 .extra1 = &min_sched_granularity_ns,
290 .extra2 = &max_sched_granularity_ns,
293 .procname = "sched_latency_ns",
294 .data = &sysctl_sched_latency,
295 .maxlen = sizeof(unsigned int),
296 .mode = 0644,
297 .proc_handler = sched_proc_update_handler,
298 .extra1 = &min_sched_granularity_ns,
299 .extra2 = &max_sched_granularity_ns,
302 .procname = "sched_wakeup_granularity_ns",
303 .data = &sysctl_sched_wakeup_granularity,
304 .maxlen = sizeof(unsigned int),
305 .mode = 0644,
306 .proc_handler = sched_proc_update_handler,
307 .extra1 = &min_wakeup_granularity_ns,
308 .extra2 = &max_wakeup_granularity_ns,
311 .procname = "sched_tunable_scaling",
312 .data = &sysctl_sched_tunable_scaling,
313 .maxlen = sizeof(enum sched_tunable_scaling),
314 .mode = 0644,
315 .proc_handler = sched_proc_update_handler,
316 .extra1 = &min_sched_tunable_scaling,
317 .extra2 = &max_sched_tunable_scaling,
320 .procname = "sched_migration_cost",
321 .data = &sysctl_sched_migration_cost,
322 .maxlen = sizeof(unsigned int),
323 .mode = 0644,
324 .proc_handler = proc_dointvec,
327 .procname = "sched_nr_migrate",
328 .data = &sysctl_sched_nr_migrate,
329 .maxlen = sizeof(unsigned int),
330 .mode = 0644,
331 .proc_handler = proc_dointvec,
334 .procname = "sched_time_avg",
335 .data = &sysctl_sched_time_avg,
336 .maxlen = sizeof(unsigned int),
337 .mode = 0644,
338 .proc_handler = proc_dointvec,
341 .procname = "sched_shares_window",
342 .data = &sysctl_sched_shares_window,
343 .maxlen = sizeof(unsigned int),
344 .mode = 0644,
345 .proc_handler = proc_dointvec,
348 .procname = "timer_migration",
349 .data = &sysctl_timer_migration,
350 .maxlen = sizeof(unsigned int),
351 .mode = 0644,
352 .proc_handler = proc_dointvec_minmax,
353 .extra1 = &zero,
354 .extra2 = &one,
356 #endif
358 .procname = "sched_rt_period_us",
359 .data = &sysctl_sched_rt_period,
360 .maxlen = sizeof(unsigned int),
361 .mode = 0644,
362 .proc_handler = sched_rt_handler,
365 .procname = "sched_rt_runtime_us",
366 .data = &sysctl_sched_rt_runtime,
367 .maxlen = sizeof(int),
368 .mode = 0644,
369 .proc_handler = sched_rt_handler,
371 #ifdef CONFIG_SCHED_AUTOGROUP
373 .procname = "sched_autogroup_enabled",
374 .data = &sysctl_sched_autogroup_enabled,
375 .maxlen = sizeof(unsigned int),
376 .mode = 0644,
377 .proc_handler = proc_dointvec_minmax,
378 .extra1 = &zero,
379 .extra2 = &one,
381 #endif
382 #ifdef CONFIG_PROVE_LOCKING
384 .procname = "prove_locking",
385 .data = &prove_locking,
386 .maxlen = sizeof(int),
387 .mode = 0644,
388 .proc_handler = proc_dointvec,
390 #endif
391 #ifdef CONFIG_LOCK_STAT
393 .procname = "lock_stat",
394 .data = &lock_stat,
395 .maxlen = sizeof(int),
396 .mode = 0644,
397 .proc_handler = proc_dointvec,
399 #endif
401 .procname = "panic",
402 .data = &panic_timeout,
403 .maxlen = sizeof(int),
404 .mode = 0644,
405 .proc_handler = proc_dointvec,
408 .procname = "core_uses_pid",
409 .data = &core_uses_pid,
410 .maxlen = sizeof(int),
411 .mode = 0644,
412 .proc_handler = proc_dointvec,
415 .procname = "core_pattern",
416 .data = core_pattern,
417 .maxlen = CORENAME_MAX_SIZE,
418 .mode = 0644,
419 .proc_handler = proc_dostring,
422 .procname = "core_pipe_limit",
423 .data = &core_pipe_limit,
424 .maxlen = sizeof(unsigned int),
425 .mode = 0644,
426 .proc_handler = proc_dointvec,
428 #ifdef CONFIG_PROC_SYSCTL
430 .procname = "tainted",
431 .maxlen = sizeof(long),
432 .mode = 0644,
433 .proc_handler = proc_taint,
435 #endif
436 #ifdef CONFIG_LATENCYTOP
438 .procname = "latencytop",
439 .data = &latencytop_enabled,
440 .maxlen = sizeof(int),
441 .mode = 0644,
442 .proc_handler = proc_dointvec,
444 #endif
445 #ifdef CONFIG_BLK_DEV_INITRD
447 .procname = "real-root-dev",
448 .data = &real_root_dev,
449 .maxlen = sizeof(int),
450 .mode = 0644,
451 .proc_handler = proc_dointvec,
453 #endif
455 .procname = "print-fatal-signals",
456 .data = &print_fatal_signals,
457 .maxlen = sizeof(int),
458 .mode = 0644,
459 .proc_handler = proc_dointvec,
461 #ifdef CONFIG_SPARC
463 .procname = "reboot-cmd",
464 .data = reboot_command,
465 .maxlen = 256,
466 .mode = 0644,
467 .proc_handler = proc_dostring,
470 .procname = "stop-a",
471 .data = &stop_a_enabled,
472 .maxlen = sizeof (int),
473 .mode = 0644,
474 .proc_handler = proc_dointvec,
477 .procname = "scons-poweroff",
478 .data = &scons_pwroff,
479 .maxlen = sizeof (int),
480 .mode = 0644,
481 .proc_handler = proc_dointvec,
483 #endif
484 #ifdef CONFIG_SPARC64
486 .procname = "tsb-ratio",
487 .data = &sysctl_tsb_ratio,
488 .maxlen = sizeof (int),
489 .mode = 0644,
490 .proc_handler = proc_dointvec,
492 #endif
493 #ifdef __hppa__
495 .procname = "soft-power",
496 .data = &pwrsw_enabled,
497 .maxlen = sizeof (int),
498 .mode = 0644,
499 .proc_handler = proc_dointvec,
502 .procname = "unaligned-trap",
503 .data = &unaligned_enabled,
504 .maxlen = sizeof (int),
505 .mode = 0644,
506 .proc_handler = proc_dointvec,
508 #endif
510 .procname = "ctrl-alt-del",
511 .data = &C_A_D,
512 .maxlen = sizeof(int),
513 .mode = 0644,
514 .proc_handler = proc_dointvec,
516 #ifdef CONFIG_FUNCTION_TRACER
518 .procname = "ftrace_enabled",
519 .data = &ftrace_enabled,
520 .maxlen = sizeof(int),
521 .mode = 0644,
522 .proc_handler = ftrace_enable_sysctl,
524 #endif
525 #ifdef CONFIG_STACK_TRACER
527 .procname = "stack_tracer_enabled",
528 .data = &stack_tracer_enabled,
529 .maxlen = sizeof(int),
530 .mode = 0644,
531 .proc_handler = stack_trace_sysctl,
533 #endif
534 #ifdef CONFIG_TRACING
536 .procname = "ftrace_dump_on_oops",
537 .data = &ftrace_dump_on_oops,
538 .maxlen = sizeof(int),
539 .mode = 0644,
540 .proc_handler = proc_dointvec,
542 #endif
543 #ifdef CONFIG_MODULES
545 .procname = "modprobe",
546 .data = &modprobe_path,
547 .maxlen = KMOD_PATH_LEN,
548 .mode = 0644,
549 .proc_handler = proc_dostring,
552 .procname = "modules_disabled",
553 .data = &modules_disabled,
554 .maxlen = sizeof(int),
555 .mode = 0644,
556 /* only handle a transition from default "0" to "1" */
557 .proc_handler = proc_dointvec_minmax,
558 .extra1 = &one,
559 .extra2 = &one,
561 #endif
562 #ifdef CONFIG_HOTPLUG
564 .procname = "hotplug",
565 .data = &uevent_helper,
566 .maxlen = UEVENT_HELPER_PATH_LEN,
567 .mode = 0644,
568 .proc_handler = proc_dostring,
570 #endif
571 #ifdef CONFIG_CHR_DEV_SG
573 .procname = "sg-big-buff",
574 .data = &sg_big_buff,
575 .maxlen = sizeof (int),
576 .mode = 0444,
577 .proc_handler = proc_dointvec,
579 #endif
580 #ifdef CONFIG_BSD_PROCESS_ACCT
582 .procname = "acct",
583 .data = &acct_parm,
584 .maxlen = 3*sizeof(int),
585 .mode = 0644,
586 .proc_handler = proc_dointvec,
588 #endif
589 #ifdef CONFIG_MAGIC_SYSRQ
591 .procname = "sysrq",
592 .data = &__sysrq_enabled,
593 .maxlen = sizeof (int),
594 .mode = 0644,
595 .proc_handler = sysrq_sysctl_handler,
597 #endif
598 #ifdef CONFIG_PROC_SYSCTL
600 .procname = "cad_pid",
601 .data = NULL,
602 .maxlen = sizeof (int),
603 .mode = 0600,
604 .proc_handler = proc_do_cad_pid,
606 #endif
608 .procname = "threads-max",
609 .data = &max_threads,
610 .maxlen = sizeof(int),
611 .mode = 0644,
612 .proc_handler = proc_dointvec,
615 .procname = "random",
616 .mode = 0555,
617 .child = random_table,
620 .procname = "usermodehelper",
621 .mode = 0555,
622 .child = usermodehelper_table,
625 .procname = "overflowuid",
626 .data = &overflowuid,
627 .maxlen = sizeof(int),
628 .mode = 0644,
629 .proc_handler = proc_dointvec_minmax,
630 .extra1 = &minolduid,
631 .extra2 = &maxolduid,
634 .procname = "overflowgid",
635 .data = &overflowgid,
636 .maxlen = sizeof(int),
637 .mode = 0644,
638 .proc_handler = proc_dointvec_minmax,
639 .extra1 = &minolduid,
640 .extra2 = &maxolduid,
642 #ifdef CONFIG_S390
643 #ifdef CONFIG_MATHEMU
645 .procname = "ieee_emulation_warnings",
646 .data = &sysctl_ieee_emulation_warnings,
647 .maxlen = sizeof(int),
648 .mode = 0644,
649 .proc_handler = proc_dointvec,
651 #endif
653 .procname = "userprocess_debug",
654 .data = &show_unhandled_signals,
655 .maxlen = sizeof(int),
656 .mode = 0644,
657 .proc_handler = proc_dointvec,
659 #endif
661 .procname = "pid_max",
662 .data = &pid_max,
663 .maxlen = sizeof (int),
664 .mode = 0644,
665 .proc_handler = proc_dointvec_minmax,
666 .extra1 = &pid_max_min,
667 .extra2 = &pid_max_max,
670 .procname = "panic_on_oops",
671 .data = &panic_on_oops,
672 .maxlen = sizeof(int),
673 .mode = 0644,
674 .proc_handler = proc_dointvec,
676 #if defined CONFIG_PRINTK
678 .procname = "printk",
679 .data = &console_loglevel,
680 .maxlen = 4*sizeof(int),
681 .mode = 0644,
682 .proc_handler = proc_dointvec,
685 .procname = "printk_ratelimit",
686 .data = &printk_ratelimit_state.interval,
687 .maxlen = sizeof(int),
688 .mode = 0644,
689 .proc_handler = proc_dointvec_jiffies,
692 .procname = "printk_ratelimit_burst",
693 .data = &printk_ratelimit_state.burst,
694 .maxlen = sizeof(int),
695 .mode = 0644,
696 .proc_handler = proc_dointvec,
699 .procname = "printk_delay",
700 .data = &printk_delay_msec,
701 .maxlen = sizeof(int),
702 .mode = 0644,
703 .proc_handler = proc_dointvec_minmax,
704 .extra1 = &zero,
705 .extra2 = &ten_thousand,
708 .procname = "dmesg_restrict",
709 .data = &dmesg_restrict,
710 .maxlen = sizeof(int),
711 .mode = 0644,
712 .proc_handler = proc_dointvec_minmax,
713 .extra1 = &zero,
714 .extra2 = &one,
717 .procname = "kptr_restrict",
718 .data = &kptr_restrict,
719 .maxlen = sizeof(int),
720 .mode = 0644,
721 .proc_handler = proc_dmesg_restrict,
722 .extra1 = &zero,
723 .extra2 = &two,
725 #endif
727 .procname = "ngroups_max",
728 .data = &ngroups_max,
729 .maxlen = sizeof (int),
730 .mode = 0444,
731 .proc_handler = proc_dointvec,
733 #if defined(CONFIG_LOCKUP_DETECTOR)
735 .procname = "watchdog",
736 .data = &watchdog_enabled,
737 .maxlen = sizeof (int),
738 .mode = 0644,
739 .proc_handler = proc_dowatchdog,
740 .extra1 = &zero,
741 .extra2 = &one,
744 .procname = "watchdog_thresh",
745 .data = &watchdog_thresh,
746 .maxlen = sizeof(int),
747 .mode = 0644,
748 .proc_handler = proc_dowatchdog,
749 .extra1 = &neg_one,
750 .extra2 = &sixty,
753 .procname = "softlockup_panic",
754 .data = &softlockup_panic,
755 .maxlen = sizeof(int),
756 .mode = 0644,
757 .proc_handler = proc_dointvec_minmax,
758 .extra1 = &zero,
759 .extra2 = &one,
762 .procname = "nmi_watchdog",
763 .data = &watchdog_enabled,
764 .maxlen = sizeof (int),
765 .mode = 0644,
766 .proc_handler = proc_dowatchdog,
767 .extra1 = &zero,
768 .extra2 = &one,
770 #endif
771 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
773 .procname = "unknown_nmi_panic",
774 .data = &unknown_nmi_panic,
775 .maxlen = sizeof (int),
776 .mode = 0644,
777 .proc_handler = proc_dointvec,
779 #endif
780 #if defined(CONFIG_X86)
782 .procname = "panic_on_unrecovered_nmi",
783 .data = &panic_on_unrecovered_nmi,
784 .maxlen = sizeof(int),
785 .mode = 0644,
786 .proc_handler = proc_dointvec,
789 .procname = "panic_on_io_nmi",
790 .data = &panic_on_io_nmi,
791 .maxlen = sizeof(int),
792 .mode = 0644,
793 .proc_handler = proc_dointvec,
796 .procname = "bootloader_type",
797 .data = &bootloader_type,
798 .maxlen = sizeof (int),
799 .mode = 0444,
800 .proc_handler = proc_dointvec,
803 .procname = "bootloader_version",
804 .data = &bootloader_version,
805 .maxlen = sizeof (int),
806 .mode = 0444,
807 .proc_handler = proc_dointvec,
810 .procname = "kstack_depth_to_print",
811 .data = &kstack_depth_to_print,
812 .maxlen = sizeof(int),
813 .mode = 0644,
814 .proc_handler = proc_dointvec,
817 .procname = "io_delay_type",
818 .data = &io_delay_type,
819 .maxlen = sizeof(int),
820 .mode = 0644,
821 .proc_handler = proc_dointvec,
823 #endif
824 #if defined(CONFIG_MMU)
826 .procname = "randomize_va_space",
827 .data = &randomize_va_space,
828 .maxlen = sizeof(int),
829 .mode = 0644,
830 .proc_handler = proc_dointvec,
832 #endif
833 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
835 .procname = "spin_retry",
836 .data = &spin_retry,
837 .maxlen = sizeof (int),
838 .mode = 0644,
839 .proc_handler = proc_dointvec,
841 #endif
842 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
844 .procname = "acpi_video_flags",
845 .data = &acpi_realmode_flags,
846 .maxlen = sizeof (unsigned long),
847 .mode = 0644,
848 .proc_handler = proc_doulongvec_minmax,
850 #endif
851 #ifdef CONFIG_IA64
853 .procname = "ignore-unaligned-usertrap",
854 .data = &no_unaligned_warning,
855 .maxlen = sizeof (int),
856 .mode = 0644,
857 .proc_handler = proc_dointvec,
860 .procname = "unaligned-dump-stack",
861 .data = &unaligned_dump_stack,
862 .maxlen = sizeof (int),
863 .mode = 0644,
864 .proc_handler = proc_dointvec,
866 #endif
867 #ifdef CONFIG_DETECT_HUNG_TASK
869 .procname = "hung_task_panic",
870 .data = &sysctl_hung_task_panic,
871 .maxlen = sizeof(int),
872 .mode = 0644,
873 .proc_handler = proc_dointvec_minmax,
874 .extra1 = &zero,
875 .extra2 = &one,
878 .procname = "hung_task_check_count",
879 .data = &sysctl_hung_task_check_count,
880 .maxlen = sizeof(unsigned long),
881 .mode = 0644,
882 .proc_handler = proc_doulongvec_minmax,
885 .procname = "hung_task_timeout_secs",
886 .data = &sysctl_hung_task_timeout_secs,
887 .maxlen = sizeof(unsigned long),
888 .mode = 0644,
889 .proc_handler = proc_dohung_task_timeout_secs,
892 .procname = "hung_task_warnings",
893 .data = &sysctl_hung_task_warnings,
894 .maxlen = sizeof(unsigned long),
895 .mode = 0644,
896 .proc_handler = proc_doulongvec_minmax,
898 #endif
899 #ifdef CONFIG_COMPAT
901 .procname = "compat-log",
902 .data = &compat_log,
903 .maxlen = sizeof (int),
904 .mode = 0644,
905 .proc_handler = proc_dointvec,
907 #endif
908 #ifdef CONFIG_RT_MUTEXES
910 .procname = "max_lock_depth",
911 .data = &max_lock_depth,
912 .maxlen = sizeof(int),
913 .mode = 0644,
914 .proc_handler = proc_dointvec,
916 #endif
918 .procname = "poweroff_cmd",
919 .data = &poweroff_cmd,
920 .maxlen = POWEROFF_CMD_PATH_LEN,
921 .mode = 0644,
922 .proc_handler = proc_dostring,
924 #ifdef CONFIG_KEYS
926 .procname = "keys",
927 .mode = 0555,
928 .child = key_sysctls,
930 #endif
931 #ifdef CONFIG_RCU_TORTURE_TEST
933 .procname = "rcutorture_runnable",
934 .data = &rcutorture_runnable,
935 .maxlen = sizeof(int),
936 .mode = 0644,
937 .proc_handler = proc_dointvec,
939 #endif
940 #ifdef CONFIG_PERF_EVENTS
942 .procname = "perf_event_paranoid",
943 .data = &sysctl_perf_event_paranoid,
944 .maxlen = sizeof(sysctl_perf_event_paranoid),
945 .mode = 0644,
946 .proc_handler = proc_dointvec,
949 .procname = "perf_event_mlock_kb",
950 .data = &sysctl_perf_event_mlock,
951 .maxlen = sizeof(sysctl_perf_event_mlock),
952 .mode = 0644,
953 .proc_handler = proc_dointvec,
956 .procname = "perf_event_max_sample_rate",
957 .data = &sysctl_perf_event_sample_rate,
958 .maxlen = sizeof(sysctl_perf_event_sample_rate),
959 .mode = 0644,
960 .proc_handler = perf_proc_update_handler,
962 #endif
963 #ifdef CONFIG_KMEMCHECK
965 .procname = "kmemcheck",
966 .data = &kmemcheck_enabled,
967 .maxlen = sizeof(int),
968 .mode = 0644,
969 .proc_handler = proc_dointvec,
971 #endif
972 #ifdef CONFIG_BLOCK
974 .procname = "blk_iopoll",
975 .data = &blk_iopoll_enabled,
976 .maxlen = sizeof(int),
977 .mode = 0644,
978 .proc_handler = proc_dointvec,
980 #endif
984 static struct ctl_table vm_table[] = {
986 .procname = "overcommit_memory",
987 .data = &sysctl_overcommit_memory,
988 .maxlen = sizeof(sysctl_overcommit_memory),
989 .mode = 0644,
990 .proc_handler = proc_dointvec_minmax,
991 .extra1 = &zero,
992 .extra2 = &two,
995 .procname = "panic_on_oom",
996 .data = &sysctl_panic_on_oom,
997 .maxlen = sizeof(sysctl_panic_on_oom),
998 .mode = 0644,
999 .proc_handler = proc_dointvec_minmax,
1000 .extra1 = &zero,
1001 .extra2 = &two,
1004 .procname = "oom_kill_allocating_task",
1005 .data = &sysctl_oom_kill_allocating_task,
1006 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1007 .mode = 0644,
1008 .proc_handler = proc_dointvec,
1011 .procname = "oom_dump_tasks",
1012 .data = &sysctl_oom_dump_tasks,
1013 .maxlen = sizeof(sysctl_oom_dump_tasks),
1014 .mode = 0644,
1015 .proc_handler = proc_dointvec,
1018 .procname = "overcommit_ratio",
1019 .data = &sysctl_overcommit_ratio,
1020 .maxlen = sizeof(sysctl_overcommit_ratio),
1021 .mode = 0644,
1022 .proc_handler = proc_dointvec,
1025 .procname = "page-cluster",
1026 .data = &page_cluster,
1027 .maxlen = sizeof(int),
1028 .mode = 0644,
1029 .proc_handler = proc_dointvec_minmax,
1030 .extra1 = &zero,
1033 .procname = "dirty_background_ratio",
1034 .data = &dirty_background_ratio,
1035 .maxlen = sizeof(dirty_background_ratio),
1036 .mode = 0644,
1037 .proc_handler = dirty_background_ratio_handler,
1038 .extra1 = &zero,
1039 .extra2 = &one_hundred,
1042 .procname = "dirty_background_bytes",
1043 .data = &dirty_background_bytes,
1044 .maxlen = sizeof(dirty_background_bytes),
1045 .mode = 0644,
1046 .proc_handler = dirty_background_bytes_handler,
1047 .extra1 = &one_ul,
1050 .procname = "dirty_ratio",
1051 .data = &vm_dirty_ratio,
1052 .maxlen = sizeof(vm_dirty_ratio),
1053 .mode = 0644,
1054 .proc_handler = dirty_ratio_handler,
1055 .extra1 = &zero,
1056 .extra2 = &one_hundred,
1059 .procname = "dirty_bytes",
1060 .data = &vm_dirty_bytes,
1061 .maxlen = sizeof(vm_dirty_bytes),
1062 .mode = 0644,
1063 .proc_handler = dirty_bytes_handler,
1064 .extra1 = &dirty_bytes_min,
1067 .procname = "dirty_writeback_centisecs",
1068 .data = &dirty_writeback_interval,
1069 .maxlen = sizeof(dirty_writeback_interval),
1070 .mode = 0644,
1071 .proc_handler = dirty_writeback_centisecs_handler,
1074 .procname = "dirty_expire_centisecs",
1075 .data = &dirty_expire_interval,
1076 .maxlen = sizeof(dirty_expire_interval),
1077 .mode = 0644,
1078 .proc_handler = proc_dointvec_minmax,
1079 .extra1 = &zero,
1082 .procname = "nr_pdflush_threads",
1083 .data = &nr_pdflush_threads,
1084 .maxlen = sizeof nr_pdflush_threads,
1085 .mode = 0444 /* read-only*/,
1086 .proc_handler = proc_dointvec,
1089 .procname = "swappiness",
1090 .data = &vm_swappiness,
1091 .maxlen = sizeof(vm_swappiness),
1092 .mode = 0644,
1093 .proc_handler = proc_dointvec_minmax,
1094 .extra1 = &zero,
1095 .extra2 = &one_hundred,
1097 #ifdef CONFIG_HUGETLB_PAGE
1099 .procname = "nr_hugepages",
1100 .data = NULL,
1101 .maxlen = sizeof(unsigned long),
1102 .mode = 0644,
1103 .proc_handler = hugetlb_sysctl_handler,
1104 .extra1 = (void *)&hugetlb_zero,
1105 .extra2 = (void *)&hugetlb_infinity,
1107 #ifdef CONFIG_NUMA
1109 .procname = "nr_hugepages_mempolicy",
1110 .data = NULL,
1111 .maxlen = sizeof(unsigned long),
1112 .mode = 0644,
1113 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1114 .extra1 = (void *)&hugetlb_zero,
1115 .extra2 = (void *)&hugetlb_infinity,
1117 #endif
1119 .procname = "hugetlb_shm_group",
1120 .data = &sysctl_hugetlb_shm_group,
1121 .maxlen = sizeof(gid_t),
1122 .mode = 0644,
1123 .proc_handler = proc_dointvec,
1126 .procname = "hugepages_treat_as_movable",
1127 .data = &hugepages_treat_as_movable,
1128 .maxlen = sizeof(int),
1129 .mode = 0644,
1130 .proc_handler = hugetlb_treat_movable_handler,
1133 .procname = "nr_overcommit_hugepages",
1134 .data = NULL,
1135 .maxlen = sizeof(unsigned long),
1136 .mode = 0644,
1137 .proc_handler = hugetlb_overcommit_handler,
1138 .extra1 = (void *)&hugetlb_zero,
1139 .extra2 = (void *)&hugetlb_infinity,
1141 #endif
1143 .procname = "lowmem_reserve_ratio",
1144 .data = &sysctl_lowmem_reserve_ratio,
1145 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1146 .mode = 0644,
1147 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1150 .procname = "drop_caches",
1151 .data = &sysctl_drop_caches,
1152 .maxlen = sizeof(int),
1153 .mode = 0644,
1154 .proc_handler = drop_caches_sysctl_handler,
1155 .extra1 = &one,
1156 .extra2 = &three,
1158 #ifdef CONFIG_COMPACTION
1160 .procname = "compact_memory",
1161 .data = &sysctl_compact_memory,
1162 .maxlen = sizeof(int),
1163 .mode = 0200,
1164 .proc_handler = sysctl_compaction_handler,
1167 .procname = "extfrag_threshold",
1168 .data = &sysctl_extfrag_threshold,
1169 .maxlen = sizeof(int),
1170 .mode = 0644,
1171 .proc_handler = sysctl_extfrag_handler,
1172 .extra1 = &min_extfrag_threshold,
1173 .extra2 = &max_extfrag_threshold,
1176 #endif /* CONFIG_COMPACTION */
1178 .procname = "min_free_kbytes",
1179 .data = &min_free_kbytes,
1180 .maxlen = sizeof(min_free_kbytes),
1181 .mode = 0644,
1182 .proc_handler = min_free_kbytes_sysctl_handler,
1183 .extra1 = &zero,
1186 .procname = "percpu_pagelist_fraction",
1187 .data = &percpu_pagelist_fraction,
1188 .maxlen = sizeof(percpu_pagelist_fraction),
1189 .mode = 0644,
1190 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1191 .extra1 = &min_percpu_pagelist_fract,
1193 #ifdef CONFIG_MMU
1195 .procname = "max_map_count",
1196 .data = &sysctl_max_map_count,
1197 .maxlen = sizeof(sysctl_max_map_count),
1198 .mode = 0644,
1199 .proc_handler = proc_dointvec_minmax,
1200 .extra1 = &zero,
1202 #else
1204 .procname = "nr_trim_pages",
1205 .data = &sysctl_nr_trim_pages,
1206 .maxlen = sizeof(sysctl_nr_trim_pages),
1207 .mode = 0644,
1208 .proc_handler = proc_dointvec_minmax,
1209 .extra1 = &zero,
1211 #endif
1213 .procname = "laptop_mode",
1214 .data = &laptop_mode,
1215 .maxlen = sizeof(laptop_mode),
1216 .mode = 0644,
1217 .proc_handler = proc_dointvec_jiffies,
1220 .procname = "block_dump",
1221 .data = &block_dump,
1222 .maxlen = sizeof(block_dump),
1223 .mode = 0644,
1224 .proc_handler = proc_dointvec,
1225 .extra1 = &zero,
1228 .procname = "vfs_cache_pressure",
1229 .data = &sysctl_vfs_cache_pressure,
1230 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1231 .mode = 0644,
1232 .proc_handler = proc_dointvec,
1233 .extra1 = &zero,
1235 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1237 .procname = "legacy_va_layout",
1238 .data = &sysctl_legacy_va_layout,
1239 .maxlen = sizeof(sysctl_legacy_va_layout),
1240 .mode = 0644,
1241 .proc_handler = proc_dointvec,
1242 .extra1 = &zero,
1244 #endif
1245 #ifdef CONFIG_NUMA
1247 .procname = "zone_reclaim_mode",
1248 .data = &zone_reclaim_mode,
1249 .maxlen = sizeof(zone_reclaim_mode),
1250 .mode = 0644,
1251 .proc_handler = proc_dointvec,
1252 .extra1 = &zero,
1255 .procname = "min_unmapped_ratio",
1256 .data = &sysctl_min_unmapped_ratio,
1257 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1258 .mode = 0644,
1259 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1260 .extra1 = &zero,
1261 .extra2 = &one_hundred,
1264 .procname = "min_slab_ratio",
1265 .data = &sysctl_min_slab_ratio,
1266 .maxlen = sizeof(sysctl_min_slab_ratio),
1267 .mode = 0644,
1268 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1269 .extra1 = &zero,
1270 .extra2 = &one_hundred,
1272 #endif
1273 #ifdef CONFIG_SMP
1275 .procname = "stat_interval",
1276 .data = &sysctl_stat_interval,
1277 .maxlen = sizeof(sysctl_stat_interval),
1278 .mode = 0644,
1279 .proc_handler = proc_dointvec_jiffies,
1281 #endif
1282 #ifdef CONFIG_MMU
1284 .procname = "mmap_min_addr",
1285 .data = &dac_mmap_min_addr,
1286 .maxlen = sizeof(unsigned long),
1287 .mode = 0644,
1288 .proc_handler = mmap_min_addr_handler,
1290 #endif
1291 #ifdef CONFIG_NUMA
1293 .procname = "numa_zonelist_order",
1294 .data = &numa_zonelist_order,
1295 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1296 .mode = 0644,
1297 .proc_handler = numa_zonelist_order_handler,
1299 #endif
1300 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1301 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1303 .procname = "vdso_enabled",
1304 .data = &vdso_enabled,
1305 .maxlen = sizeof(vdso_enabled),
1306 .mode = 0644,
1307 .proc_handler = proc_dointvec,
1308 .extra1 = &zero,
1310 #endif
1311 #ifdef CONFIG_HIGHMEM
1313 .procname = "highmem_is_dirtyable",
1314 .data = &vm_highmem_is_dirtyable,
1315 .maxlen = sizeof(vm_highmem_is_dirtyable),
1316 .mode = 0644,
1317 .proc_handler = proc_dointvec_minmax,
1318 .extra1 = &zero,
1319 .extra2 = &one,
1321 #endif
1323 .procname = "scan_unevictable_pages",
1324 .data = &scan_unevictable_pages,
1325 .maxlen = sizeof(scan_unevictable_pages),
1326 .mode = 0644,
1327 .proc_handler = scan_unevictable_handler,
1329 #ifdef CONFIG_MEMORY_FAILURE
1331 .procname = "memory_failure_early_kill",
1332 .data = &sysctl_memory_failure_early_kill,
1333 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1334 .mode = 0644,
1335 .proc_handler = proc_dointvec_minmax,
1336 .extra1 = &zero,
1337 .extra2 = &one,
1340 .procname = "memory_failure_recovery",
1341 .data = &sysctl_memory_failure_recovery,
1342 .maxlen = sizeof(sysctl_memory_failure_recovery),
1343 .mode = 0644,
1344 .proc_handler = proc_dointvec_minmax,
1345 .extra1 = &zero,
1346 .extra2 = &one,
1348 #endif
1352 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1353 static struct ctl_table binfmt_misc_table[] = {
1356 #endif
1358 static struct ctl_table fs_table[] = {
1360 .procname = "inode-nr",
1361 .data = &inodes_stat,
1362 .maxlen = 2*sizeof(int),
1363 .mode = 0444,
1364 .proc_handler = proc_nr_inodes,
1367 .procname = "inode-state",
1368 .data = &inodes_stat,
1369 .maxlen = 7*sizeof(int),
1370 .mode = 0444,
1371 .proc_handler = proc_nr_inodes,
1374 .procname = "file-nr",
1375 .data = &files_stat,
1376 .maxlen = sizeof(files_stat),
1377 .mode = 0444,
1378 .proc_handler = proc_nr_files,
1381 .procname = "file-max",
1382 .data = &files_stat.max_files,
1383 .maxlen = sizeof(files_stat.max_files),
1384 .mode = 0644,
1385 .proc_handler = proc_doulongvec_minmax,
1388 .procname = "nr_open",
1389 .data = &sysctl_nr_open,
1390 .maxlen = sizeof(int),
1391 .mode = 0644,
1392 .proc_handler = proc_dointvec_minmax,
1393 .extra1 = &sysctl_nr_open_min,
1394 .extra2 = &sysctl_nr_open_max,
1397 .procname = "dentry-state",
1398 .data = &dentry_stat,
1399 .maxlen = 6*sizeof(int),
1400 .mode = 0444,
1401 .proc_handler = proc_nr_dentry,
1404 .procname = "overflowuid",
1405 .data = &fs_overflowuid,
1406 .maxlen = sizeof(int),
1407 .mode = 0644,
1408 .proc_handler = proc_dointvec_minmax,
1409 .extra1 = &minolduid,
1410 .extra2 = &maxolduid,
1413 .procname = "overflowgid",
1414 .data = &fs_overflowgid,
1415 .maxlen = sizeof(int),
1416 .mode = 0644,
1417 .proc_handler = proc_dointvec_minmax,
1418 .extra1 = &minolduid,
1419 .extra2 = &maxolduid,
1421 #ifdef CONFIG_FILE_LOCKING
1423 .procname = "leases-enable",
1424 .data = &leases_enable,
1425 .maxlen = sizeof(int),
1426 .mode = 0644,
1427 .proc_handler = proc_dointvec,
1429 #endif
1430 #ifdef CONFIG_DNOTIFY
1432 .procname = "dir-notify-enable",
1433 .data = &dir_notify_enable,
1434 .maxlen = sizeof(int),
1435 .mode = 0644,
1436 .proc_handler = proc_dointvec,
1438 #endif
1439 #ifdef CONFIG_MMU
1440 #ifdef CONFIG_FILE_LOCKING
1442 .procname = "lease-break-time",
1443 .data = &lease_break_time,
1444 .maxlen = sizeof(int),
1445 .mode = 0644,
1446 .proc_handler = proc_dointvec,
1448 #endif
1449 #ifdef CONFIG_AIO
1451 .procname = "aio-nr",
1452 .data = &aio_nr,
1453 .maxlen = sizeof(aio_nr),
1454 .mode = 0444,
1455 .proc_handler = proc_doulongvec_minmax,
1458 .procname = "aio-max-nr",
1459 .data = &aio_max_nr,
1460 .maxlen = sizeof(aio_max_nr),
1461 .mode = 0644,
1462 .proc_handler = proc_doulongvec_minmax,
1464 #endif /* CONFIG_AIO */
1465 #ifdef CONFIG_INOTIFY_USER
1467 .procname = "inotify",
1468 .mode = 0555,
1469 .child = inotify_table,
1471 #endif
1472 #ifdef CONFIG_EPOLL
1474 .procname = "epoll",
1475 .mode = 0555,
1476 .child = epoll_table,
1478 #endif
1479 #endif
1481 .procname = "suid_dumpable",
1482 .data = &suid_dumpable,
1483 .maxlen = sizeof(int),
1484 .mode = 0644,
1485 .proc_handler = proc_dointvec_minmax,
1486 .extra1 = &zero,
1487 .extra2 = &two,
1489 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1491 .procname = "binfmt_misc",
1492 .mode = 0555,
1493 .child = binfmt_misc_table,
1495 #endif
1497 .procname = "pipe-max-size",
1498 .data = &pipe_max_size,
1499 .maxlen = sizeof(int),
1500 .mode = 0644,
1501 .proc_handler = &pipe_proc_fn,
1502 .extra1 = &pipe_min_size,
1507 static struct ctl_table debug_table[] = {
1508 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1509 defined(CONFIG_S390) || defined(CONFIG_TILE)
1511 .procname = "exception-trace",
1512 .data = &show_unhandled_signals,
1513 .maxlen = sizeof(int),
1514 .mode = 0644,
1515 .proc_handler = proc_dointvec
1517 #endif
1518 #if defined(CONFIG_OPTPROBES)
1520 .procname = "kprobes-optimization",
1521 .data = &sysctl_kprobes_optimization,
1522 .maxlen = sizeof(int),
1523 .mode = 0644,
1524 .proc_handler = proc_kprobes_optimization_handler,
1525 .extra1 = &zero,
1526 .extra2 = &one,
1528 #endif
1532 static struct ctl_table dev_table[] = {
1536 static DEFINE_SPINLOCK(sysctl_lock);
1538 /* called under sysctl_lock */
1539 static int use_table(struct ctl_table_header *p)
1541 if (unlikely(p->unregistering))
1542 return 0;
1543 p->used++;
1544 return 1;
1547 /* called under sysctl_lock */
1548 static void unuse_table(struct ctl_table_header *p)
1550 if (!--p->used)
1551 if (unlikely(p->unregistering))
1552 complete(p->unregistering);
1555 /* called under sysctl_lock, will reacquire if has to wait */
1556 static void start_unregistering(struct ctl_table_header *p)
1559 * if p->used is 0, nobody will ever touch that entry again;
1560 * we'll eliminate all paths to it before dropping sysctl_lock
1562 if (unlikely(p->used)) {
1563 struct completion wait;
1564 init_completion(&wait);
1565 p->unregistering = &wait;
1566 spin_unlock(&sysctl_lock);
1567 wait_for_completion(&wait);
1568 spin_lock(&sysctl_lock);
1569 } else {
1570 /* anything non-NULL; we'll never dereference it */
1571 p->unregistering = ERR_PTR(-EINVAL);
1574 * do not remove from the list until nobody holds it; walking the
1575 * list in do_sysctl() relies on that.
1577 list_del_init(&p->ctl_entry);
1580 void sysctl_head_get(struct ctl_table_header *head)
1582 spin_lock(&sysctl_lock);
1583 head->count++;
1584 spin_unlock(&sysctl_lock);
1587 static void free_head(struct rcu_head *rcu)
1589 kfree(container_of(rcu, struct ctl_table_header, rcu));
1592 void sysctl_head_put(struct ctl_table_header *head)
1594 spin_lock(&sysctl_lock);
1595 if (!--head->count)
1596 call_rcu(&head->rcu, free_head);
1597 spin_unlock(&sysctl_lock);
1600 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1602 if (!head)
1603 BUG();
1604 spin_lock(&sysctl_lock);
1605 if (!use_table(head))
1606 head = ERR_PTR(-ENOENT);
1607 spin_unlock(&sysctl_lock);
1608 return head;
1611 void sysctl_head_finish(struct ctl_table_header *head)
1613 if (!head)
1614 return;
1615 spin_lock(&sysctl_lock);
1616 unuse_table(head);
1617 spin_unlock(&sysctl_lock);
1620 static struct ctl_table_set *
1621 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1623 struct ctl_table_set *set = &root->default_set;
1624 if (root->lookup)
1625 set = root->lookup(root, namespaces);
1626 return set;
1629 static struct list_head *
1630 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1632 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1633 return &set->list;
1636 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1637 struct ctl_table_header *prev)
1639 struct ctl_table_root *root;
1640 struct list_head *header_list;
1641 struct ctl_table_header *head;
1642 struct list_head *tmp;
1644 spin_lock(&sysctl_lock);
1645 if (prev) {
1646 head = prev;
1647 tmp = &prev->ctl_entry;
1648 unuse_table(prev);
1649 goto next;
1651 tmp = &root_table_header.ctl_entry;
1652 for (;;) {
1653 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1655 if (!use_table(head))
1656 goto next;
1657 spin_unlock(&sysctl_lock);
1658 return head;
1659 next:
1660 root = head->root;
1661 tmp = tmp->next;
1662 header_list = lookup_header_list(root, namespaces);
1663 if (tmp != header_list)
1664 continue;
1666 do {
1667 root = list_entry(root->root_list.next,
1668 struct ctl_table_root, root_list);
1669 if (root == &sysctl_table_root)
1670 goto out;
1671 header_list = lookup_header_list(root, namespaces);
1672 } while (list_empty(header_list));
1673 tmp = header_list->next;
1675 out:
1676 spin_unlock(&sysctl_lock);
1677 return NULL;
1680 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1682 return __sysctl_head_next(current->nsproxy, prev);
1685 void register_sysctl_root(struct ctl_table_root *root)
1687 spin_lock(&sysctl_lock);
1688 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1689 spin_unlock(&sysctl_lock);
1693 * sysctl_perm does NOT grant the superuser all rights automatically, because
1694 * some sysctl variables are readonly even to root.
1697 static int test_perm(int mode, int op)
1699 if (!current_euid())
1700 mode >>= 6;
1701 else if (in_egroup_p(0))
1702 mode >>= 3;
1703 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1704 return 0;
1705 return -EACCES;
1708 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1710 int mode;
1712 if (root->permissions)
1713 mode = root->permissions(root, current->nsproxy, table);
1714 else
1715 mode = table->mode;
1717 return test_perm(mode, op);
1720 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1722 for (; table->procname; table++) {
1723 table->parent = parent;
1724 if (table->child)
1725 sysctl_set_parent(table, table->child);
1729 static __init int sysctl_init(void)
1731 sysctl_set_parent(NULL, root_table);
1732 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1733 sysctl_check_table(current->nsproxy, root_table);
1734 #endif
1735 return 0;
1738 core_initcall(sysctl_init);
1740 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1741 struct ctl_table *table)
1743 struct ctl_table *p;
1744 const char *s = branch->procname;
1746 /* branch should have named subdirectory as its first element */
1747 if (!s || !branch->child)
1748 return NULL;
1750 /* ... and nothing else */
1751 if (branch[1].procname)
1752 return NULL;
1754 /* table should contain subdirectory with the same name */
1755 for (p = table; p->procname; p++) {
1756 if (!p->child)
1757 continue;
1758 if (p->procname && strcmp(p->procname, s) == 0)
1759 return p;
1761 return NULL;
1764 /* see if attaching q to p would be an improvement */
1765 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1767 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1768 struct ctl_table *next;
1769 int is_better = 0;
1770 int not_in_parent = !p->attached_by;
1772 while ((next = is_branch_in(by, to)) != NULL) {
1773 if (by == q->attached_by)
1774 is_better = 1;
1775 if (to == p->attached_by)
1776 not_in_parent = 1;
1777 by = by->child;
1778 to = next->child;
1781 if (is_better && not_in_parent) {
1782 q->attached_by = by;
1783 q->attached_to = to;
1784 q->parent = p;
1789 * __register_sysctl_paths - register a sysctl hierarchy
1790 * @root: List of sysctl headers to register on
1791 * @namespaces: Data to compute which lists of sysctl entries are visible
1792 * @path: The path to the directory the sysctl table is in.
1793 * @table: the top-level table structure
1795 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1796 * array. A completely 0 filled entry terminates the table.
1798 * The members of the &struct ctl_table structure are used as follows:
1800 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1801 * enter a sysctl file
1803 * data - a pointer to data for use by proc_handler
1805 * maxlen - the maximum size in bytes of the data
1807 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1809 * child - a pointer to the child sysctl table if this entry is a directory, or
1810 * %NULL.
1812 * proc_handler - the text handler routine (described below)
1814 * de - for internal use by the sysctl routines
1816 * extra1, extra2 - extra pointers usable by the proc handler routines
1818 * Leaf nodes in the sysctl tree will be represented by a single file
1819 * under /proc; non-leaf nodes will be represented by directories.
1821 * sysctl(2) can automatically manage read and write requests through
1822 * the sysctl table. The data and maxlen fields of the ctl_table
1823 * struct enable minimal validation of the values being written to be
1824 * performed, and the mode field allows minimal authentication.
1826 * There must be a proc_handler routine for any terminal nodes
1827 * mirrored under /proc/sys (non-terminals are handled by a built-in
1828 * directory handler). Several default handlers are available to
1829 * cover common cases -
1831 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1832 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1833 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1835 * It is the handler's job to read the input buffer from user memory
1836 * and process it. The handler should return 0 on success.
1838 * This routine returns %NULL on a failure to register, and a pointer
1839 * to the table header on success.
1841 struct ctl_table_header *__register_sysctl_paths(
1842 struct ctl_table_root *root,
1843 struct nsproxy *namespaces,
1844 const struct ctl_path *path, struct ctl_table *table)
1846 struct ctl_table_header *header;
1847 struct ctl_table *new, **prevp;
1848 unsigned int n, npath;
1849 struct ctl_table_set *set;
1851 /* Count the path components */
1852 for (npath = 0; path[npath].procname; ++npath)
1856 * For each path component, allocate a 2-element ctl_table array.
1857 * The first array element will be filled with the sysctl entry
1858 * for this, the second will be the sentinel (procname == 0).
1860 * We allocate everything in one go so that we don't have to
1861 * worry about freeing additional memory in unregister_sysctl_table.
1863 header = kzalloc(sizeof(struct ctl_table_header) +
1864 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1865 if (!header)
1866 return NULL;
1868 new = (struct ctl_table *) (header + 1);
1870 /* Now connect the dots */
1871 prevp = &header->ctl_table;
1872 for (n = 0; n < npath; ++n, ++path) {
1873 /* Copy the procname */
1874 new->procname = path->procname;
1875 new->mode = 0555;
1877 *prevp = new;
1878 prevp = &new->child;
1880 new += 2;
1882 *prevp = table;
1883 header->ctl_table_arg = table;
1885 INIT_LIST_HEAD(&header->ctl_entry);
1886 header->used = 0;
1887 header->unregistering = NULL;
1888 header->root = root;
1889 sysctl_set_parent(NULL, header->ctl_table);
1890 header->count = 1;
1891 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1892 if (sysctl_check_table(namespaces, header->ctl_table)) {
1893 kfree(header);
1894 return NULL;
1896 #endif
1897 spin_lock(&sysctl_lock);
1898 header->set = lookup_header_set(root, namespaces);
1899 header->attached_by = header->ctl_table;
1900 header->attached_to = root_table;
1901 header->parent = &root_table_header;
1902 for (set = header->set; set; set = set->parent) {
1903 struct ctl_table_header *p;
1904 list_for_each_entry(p, &set->list, ctl_entry) {
1905 if (p->unregistering)
1906 continue;
1907 try_attach(p, header);
1910 header->parent->count++;
1911 list_add_tail(&header->ctl_entry, &header->set->list);
1912 spin_unlock(&sysctl_lock);
1914 return header;
1918 * register_sysctl_table_path - register a sysctl table hierarchy
1919 * @path: The path to the directory the sysctl table is in.
1920 * @table: the top-level table structure
1922 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1923 * array. A completely 0 filled entry terminates the table.
1925 * See __register_sysctl_paths for more details.
1927 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1928 struct ctl_table *table)
1930 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1931 path, table);
1935 * register_sysctl_table - register a sysctl table hierarchy
1936 * @table: the top-level table structure
1938 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1939 * array. A completely 0 filled entry terminates the table.
1941 * See register_sysctl_paths for more details.
1943 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1945 static const struct ctl_path null_path[] = { {} };
1947 return register_sysctl_paths(null_path, table);
1951 * unregister_sysctl_table - unregister a sysctl table hierarchy
1952 * @header: the header returned from register_sysctl_table
1954 * Unregisters the sysctl table and all children. proc entries may not
1955 * actually be removed until they are no longer used by anyone.
1957 void unregister_sysctl_table(struct ctl_table_header * header)
1959 might_sleep();
1961 if (header == NULL)
1962 return;
1964 spin_lock(&sysctl_lock);
1965 start_unregistering(header);
1966 if (!--header->parent->count) {
1967 WARN_ON(1);
1968 call_rcu(&header->parent->rcu, free_head);
1970 if (!--header->count)
1971 call_rcu(&header->rcu, free_head);
1972 spin_unlock(&sysctl_lock);
1975 int sysctl_is_seen(struct ctl_table_header *p)
1977 struct ctl_table_set *set = p->set;
1978 int res;
1979 spin_lock(&sysctl_lock);
1980 if (p->unregistering)
1981 res = 0;
1982 else if (!set->is_seen)
1983 res = 1;
1984 else
1985 res = set->is_seen(set);
1986 spin_unlock(&sysctl_lock);
1987 return res;
1990 void setup_sysctl_set(struct ctl_table_set *p,
1991 struct ctl_table_set *parent,
1992 int (*is_seen)(struct ctl_table_set *))
1994 INIT_LIST_HEAD(&p->list);
1995 p->parent = parent ? parent : &sysctl_table_root.default_set;
1996 p->is_seen = is_seen;
1999 #else /* !CONFIG_SYSCTL */
2000 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2002 return NULL;
2005 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2006 struct ctl_table *table)
2008 return NULL;
2011 void unregister_sysctl_table(struct ctl_table_header * table)
2015 void setup_sysctl_set(struct ctl_table_set *p,
2016 struct ctl_table_set *parent,
2017 int (*is_seen)(struct ctl_table_set *))
2021 void sysctl_head_put(struct ctl_table_header *head)
2025 #endif /* CONFIG_SYSCTL */
2028 * /proc/sys support
2031 #ifdef CONFIG_PROC_SYSCTL
2033 static int _proc_do_string(void* data, int maxlen, int write,
2034 void __user *buffer,
2035 size_t *lenp, loff_t *ppos)
2037 size_t len;
2038 char __user *p;
2039 char c;
2041 if (!data || !maxlen || !*lenp) {
2042 *lenp = 0;
2043 return 0;
2046 if (write) {
2047 len = 0;
2048 p = buffer;
2049 while (len < *lenp) {
2050 if (get_user(c, p++))
2051 return -EFAULT;
2052 if (c == 0 || c == '\n')
2053 break;
2054 len++;
2056 if (len >= maxlen)
2057 len = maxlen-1;
2058 if(copy_from_user(data, buffer, len))
2059 return -EFAULT;
2060 ((char *) data)[len] = 0;
2061 *ppos += *lenp;
2062 } else {
2063 len = strlen(data);
2064 if (len > maxlen)
2065 len = maxlen;
2067 if (*ppos > len) {
2068 *lenp = 0;
2069 return 0;
2072 data += *ppos;
2073 len -= *ppos;
2075 if (len > *lenp)
2076 len = *lenp;
2077 if (len)
2078 if(copy_to_user(buffer, data, len))
2079 return -EFAULT;
2080 if (len < *lenp) {
2081 if(put_user('\n', ((char __user *) buffer) + len))
2082 return -EFAULT;
2083 len++;
2085 *lenp = len;
2086 *ppos += len;
2088 return 0;
2092 * proc_dostring - read a string sysctl
2093 * @table: the sysctl table
2094 * @write: %TRUE if this is a write to the sysctl file
2095 * @buffer: the user buffer
2096 * @lenp: the size of the user buffer
2097 * @ppos: file position
2099 * Reads/writes a string from/to the user buffer. If the kernel
2100 * buffer provided is not large enough to hold the string, the
2101 * string is truncated. The copied string is %NULL-terminated.
2102 * If the string is being read by the user process, it is copied
2103 * and a newline '\n' is added. It is truncated if the buffer is
2104 * not large enough.
2106 * Returns 0 on success.
2108 int proc_dostring(struct ctl_table *table, int write,
2109 void __user *buffer, size_t *lenp, loff_t *ppos)
2111 return _proc_do_string(table->data, table->maxlen, write,
2112 buffer, lenp, ppos);
2115 static size_t proc_skip_spaces(char **buf)
2117 size_t ret;
2118 char *tmp = skip_spaces(*buf);
2119 ret = tmp - *buf;
2120 *buf = tmp;
2121 return ret;
2124 static void proc_skip_char(char **buf, size_t *size, const char v)
2126 while (*size) {
2127 if (**buf != v)
2128 break;
2129 (*size)--;
2130 (*buf)++;
2134 #define TMPBUFLEN 22
2136 * proc_get_long - reads an ASCII formatted integer from a user buffer
2138 * @buf: a kernel buffer
2139 * @size: size of the kernel buffer
2140 * @val: this is where the number will be stored
2141 * @neg: set to %TRUE if number is negative
2142 * @perm_tr: a vector which contains the allowed trailers
2143 * @perm_tr_len: size of the perm_tr vector
2144 * @tr: pointer to store the trailer character
2146 * In case of success %0 is returned and @buf and @size are updated with
2147 * the amount of bytes read. If @tr is non-NULL and a trailing
2148 * character exists (size is non-zero after returning from this
2149 * function), @tr is updated with the trailing character.
2151 static int proc_get_long(char **buf, size_t *size,
2152 unsigned long *val, bool *neg,
2153 const char *perm_tr, unsigned perm_tr_len, char *tr)
2155 int len;
2156 char *p, tmp[TMPBUFLEN];
2158 if (!*size)
2159 return -EINVAL;
2161 len = *size;
2162 if (len > TMPBUFLEN - 1)
2163 len = TMPBUFLEN - 1;
2165 memcpy(tmp, *buf, len);
2167 tmp[len] = 0;
2168 p = tmp;
2169 if (*p == '-' && *size > 1) {
2170 *neg = true;
2171 p++;
2172 } else
2173 *neg = false;
2174 if (!isdigit(*p))
2175 return -EINVAL;
2177 *val = simple_strtoul(p, &p, 0);
2179 len = p - tmp;
2181 /* We don't know if the next char is whitespace thus we may accept
2182 * invalid integers (e.g. 1234...a) or two integers instead of one
2183 * (e.g. 123...1). So lets not allow such large numbers. */
2184 if (len == TMPBUFLEN - 1)
2185 return -EINVAL;
2187 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2188 return -EINVAL;
2190 if (tr && (len < *size))
2191 *tr = *p;
2193 *buf += len;
2194 *size -= len;
2196 return 0;
2200 * proc_put_long - converts an integer to a decimal ASCII formatted string
2202 * @buf: the user buffer
2203 * @size: the size of the user buffer
2204 * @val: the integer to be converted
2205 * @neg: sign of the number, %TRUE for negative
2207 * In case of success %0 is returned and @buf and @size are updated with
2208 * the amount of bytes written.
2210 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2211 bool neg)
2213 int len;
2214 char tmp[TMPBUFLEN], *p = tmp;
2216 sprintf(p, "%s%lu", neg ? "-" : "", val);
2217 len = strlen(tmp);
2218 if (len > *size)
2219 len = *size;
2220 if (copy_to_user(*buf, tmp, len))
2221 return -EFAULT;
2222 *size -= len;
2223 *buf += len;
2224 return 0;
2226 #undef TMPBUFLEN
2228 static int proc_put_char(void __user **buf, size_t *size, char c)
2230 if (*size) {
2231 char __user **buffer = (char __user **)buf;
2232 if (put_user(c, *buffer))
2233 return -EFAULT;
2234 (*size)--, (*buffer)++;
2235 *buf = *buffer;
2237 return 0;
2240 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2241 int *valp,
2242 int write, void *data)
2244 if (write) {
2245 *valp = *negp ? -*lvalp : *lvalp;
2246 } else {
2247 int val = *valp;
2248 if (val < 0) {
2249 *negp = true;
2250 *lvalp = (unsigned long)-val;
2251 } else {
2252 *negp = false;
2253 *lvalp = (unsigned long)val;
2256 return 0;
2259 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2261 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2262 int write, void __user *buffer,
2263 size_t *lenp, loff_t *ppos,
2264 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2265 int write, void *data),
2266 void *data)
2268 int *i, vleft, first = 1, err = 0;
2269 unsigned long page = 0;
2270 size_t left;
2271 char *kbuf;
2273 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2274 *lenp = 0;
2275 return 0;
2278 i = (int *) tbl_data;
2279 vleft = table->maxlen / sizeof(*i);
2280 left = *lenp;
2282 if (!conv)
2283 conv = do_proc_dointvec_conv;
2285 if (write) {
2286 if (left > PAGE_SIZE - 1)
2287 left = PAGE_SIZE - 1;
2288 page = __get_free_page(GFP_TEMPORARY);
2289 kbuf = (char *) page;
2290 if (!kbuf)
2291 return -ENOMEM;
2292 if (copy_from_user(kbuf, buffer, left)) {
2293 err = -EFAULT;
2294 goto free;
2296 kbuf[left] = 0;
2299 for (; left && vleft--; i++, first=0) {
2300 unsigned long lval;
2301 bool neg;
2303 if (write) {
2304 left -= proc_skip_spaces(&kbuf);
2306 if (!left)
2307 break;
2308 err = proc_get_long(&kbuf, &left, &lval, &neg,
2309 proc_wspace_sep,
2310 sizeof(proc_wspace_sep), NULL);
2311 if (err)
2312 break;
2313 if (conv(&neg, &lval, i, 1, data)) {
2314 err = -EINVAL;
2315 break;
2317 } else {
2318 if (conv(&neg, &lval, i, 0, data)) {
2319 err = -EINVAL;
2320 break;
2322 if (!first)
2323 err = proc_put_char(&buffer, &left, '\t');
2324 if (err)
2325 break;
2326 err = proc_put_long(&buffer, &left, lval, neg);
2327 if (err)
2328 break;
2332 if (!write && !first && left && !err)
2333 err = proc_put_char(&buffer, &left, '\n');
2334 if (write && !err && left)
2335 left -= proc_skip_spaces(&kbuf);
2336 free:
2337 if (write) {
2338 free_page(page);
2339 if (first)
2340 return err ? : -EINVAL;
2342 *lenp -= left;
2343 *ppos += *lenp;
2344 return err;
2347 static int do_proc_dointvec(struct ctl_table *table, int write,
2348 void __user *buffer, size_t *lenp, loff_t *ppos,
2349 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2350 int write, void *data),
2351 void *data)
2353 return __do_proc_dointvec(table->data, table, write,
2354 buffer, lenp, ppos, conv, data);
2358 * proc_dointvec - read a vector of integers
2359 * @table: the sysctl table
2360 * @write: %TRUE if this is a write to the sysctl file
2361 * @buffer: the user buffer
2362 * @lenp: the size of the user buffer
2363 * @ppos: file position
2365 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2366 * values from/to the user buffer, treated as an ASCII string.
2368 * Returns 0 on success.
2370 int proc_dointvec(struct ctl_table *table, int write,
2371 void __user *buffer, size_t *lenp, loff_t *ppos)
2373 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2374 NULL,NULL);
2378 * Taint values can only be increased
2379 * This means we can safely use a temporary.
2381 static int proc_taint(struct ctl_table *table, int write,
2382 void __user *buffer, size_t *lenp, loff_t *ppos)
2384 struct ctl_table t;
2385 unsigned long tmptaint = get_taint();
2386 int err;
2388 if (write && !capable(CAP_SYS_ADMIN))
2389 return -EPERM;
2391 t = *table;
2392 t.data = &tmptaint;
2393 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2394 if (err < 0)
2395 return err;
2397 if (write) {
2399 * Poor man's atomic or. Not worth adding a primitive
2400 * to everyone's atomic.h for this
2402 int i;
2403 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2404 if ((tmptaint >> i) & 1)
2405 add_taint(i);
2409 return err;
2412 #ifdef CONFIG_PRINTK
2413 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2414 void __user *buffer, size_t *lenp, loff_t *ppos)
2416 if (write && !capable(CAP_SYS_ADMIN))
2417 return -EPERM;
2419 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2421 #endif
2423 struct do_proc_dointvec_minmax_conv_param {
2424 int *min;
2425 int *max;
2428 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2429 int *valp,
2430 int write, void *data)
2432 struct do_proc_dointvec_minmax_conv_param *param = data;
2433 if (write) {
2434 int val = *negp ? -*lvalp : *lvalp;
2435 if ((param->min && *param->min > val) ||
2436 (param->max && *param->max < val))
2437 return -EINVAL;
2438 *valp = val;
2439 } else {
2440 int val = *valp;
2441 if (val < 0) {
2442 *negp = true;
2443 *lvalp = (unsigned long)-val;
2444 } else {
2445 *negp = false;
2446 *lvalp = (unsigned long)val;
2449 return 0;
2453 * proc_dointvec_minmax - read a vector of integers with min/max values
2454 * @table: the sysctl table
2455 * @write: %TRUE if this is a write to the sysctl file
2456 * @buffer: the user buffer
2457 * @lenp: the size of the user buffer
2458 * @ppos: file position
2460 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2461 * values from/to the user buffer, treated as an ASCII string.
2463 * This routine will ensure the values are within the range specified by
2464 * table->extra1 (min) and table->extra2 (max).
2466 * Returns 0 on success.
2468 int proc_dointvec_minmax(struct ctl_table *table, int write,
2469 void __user *buffer, size_t *lenp, loff_t *ppos)
2471 struct do_proc_dointvec_minmax_conv_param param = {
2472 .min = (int *) table->extra1,
2473 .max = (int *) table->extra2,
2475 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2476 do_proc_dointvec_minmax_conv, &param);
2479 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2480 void __user *buffer,
2481 size_t *lenp, loff_t *ppos,
2482 unsigned long convmul,
2483 unsigned long convdiv)
2485 unsigned long *i, *min, *max;
2486 int vleft, first = 1, err = 0;
2487 unsigned long page = 0;
2488 size_t left;
2489 char *kbuf;
2491 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2492 *lenp = 0;
2493 return 0;
2496 i = (unsigned long *) data;
2497 min = (unsigned long *) table->extra1;
2498 max = (unsigned long *) table->extra2;
2499 vleft = table->maxlen / sizeof(unsigned long);
2500 left = *lenp;
2502 if (write) {
2503 if (left > PAGE_SIZE - 1)
2504 left = PAGE_SIZE - 1;
2505 page = __get_free_page(GFP_TEMPORARY);
2506 kbuf = (char *) page;
2507 if (!kbuf)
2508 return -ENOMEM;
2509 if (copy_from_user(kbuf, buffer, left)) {
2510 err = -EFAULT;
2511 goto free;
2513 kbuf[left] = 0;
2516 for (; left && vleft--; i++, first = 0) {
2517 unsigned long val;
2519 if (write) {
2520 bool neg;
2522 left -= proc_skip_spaces(&kbuf);
2524 err = proc_get_long(&kbuf, &left, &val, &neg,
2525 proc_wspace_sep,
2526 sizeof(proc_wspace_sep), NULL);
2527 if (err)
2528 break;
2529 if (neg)
2530 continue;
2531 if ((min && val < *min) || (max && val > *max))
2532 continue;
2533 *i = val;
2534 } else {
2535 val = convdiv * (*i) / convmul;
2536 if (!first)
2537 err = proc_put_char(&buffer, &left, '\t');
2538 err = proc_put_long(&buffer, &left, val, false);
2539 if (err)
2540 break;
2544 if (!write && !first && left && !err)
2545 err = proc_put_char(&buffer, &left, '\n');
2546 if (write && !err)
2547 left -= proc_skip_spaces(&kbuf);
2548 free:
2549 if (write) {
2550 free_page(page);
2551 if (first)
2552 return err ? : -EINVAL;
2554 *lenp -= left;
2555 *ppos += *lenp;
2556 return err;
2559 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2560 void __user *buffer,
2561 size_t *lenp, loff_t *ppos,
2562 unsigned long convmul,
2563 unsigned long convdiv)
2565 return __do_proc_doulongvec_minmax(table->data, table, write,
2566 buffer, lenp, ppos, convmul, convdiv);
2570 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2571 * @table: the sysctl table
2572 * @write: %TRUE if this is a write to the sysctl file
2573 * @buffer: the user buffer
2574 * @lenp: the size of the user buffer
2575 * @ppos: file position
2577 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2578 * values from/to the user buffer, treated as an ASCII string.
2580 * This routine will ensure the values are within the range specified by
2581 * table->extra1 (min) and table->extra2 (max).
2583 * Returns 0 on success.
2585 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2586 void __user *buffer, size_t *lenp, loff_t *ppos)
2588 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2592 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2593 * @table: the sysctl table
2594 * @write: %TRUE if this is a write to the sysctl file
2595 * @buffer: the user buffer
2596 * @lenp: the size of the user buffer
2597 * @ppos: file position
2599 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2600 * values from/to the user buffer, treated as an ASCII string. The values
2601 * are treated as milliseconds, and converted to jiffies when they are stored.
2603 * This routine will ensure the values are within the range specified by
2604 * table->extra1 (min) and table->extra2 (max).
2606 * Returns 0 on success.
2608 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2609 void __user *buffer,
2610 size_t *lenp, loff_t *ppos)
2612 return do_proc_doulongvec_minmax(table, write, buffer,
2613 lenp, ppos, HZ, 1000l);
2617 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2618 int *valp,
2619 int write, void *data)
2621 if (write) {
2622 if (*lvalp > LONG_MAX / HZ)
2623 return 1;
2624 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2625 } else {
2626 int val = *valp;
2627 unsigned long lval;
2628 if (val < 0) {
2629 *negp = true;
2630 lval = (unsigned long)-val;
2631 } else {
2632 *negp = false;
2633 lval = (unsigned long)val;
2635 *lvalp = lval / HZ;
2637 return 0;
2640 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2641 int *valp,
2642 int write, void *data)
2644 if (write) {
2645 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2646 return 1;
2647 *valp = clock_t_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_clock_t(lval);
2660 return 0;
2663 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2664 int *valp,
2665 int write, void *data)
2667 if (write) {
2668 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2669 } else {
2670 int val = *valp;
2671 unsigned long lval;
2672 if (val < 0) {
2673 *negp = true;
2674 lval = (unsigned long)-val;
2675 } else {
2676 *negp = false;
2677 lval = (unsigned long)val;
2679 *lvalp = jiffies_to_msecs(lval);
2681 return 0;
2685 * proc_dointvec_jiffies - read a vector of integers as seconds
2686 * @table: the sysctl table
2687 * @write: %TRUE if this is a write to the sysctl file
2688 * @buffer: the user buffer
2689 * @lenp: the size of the user buffer
2690 * @ppos: file position
2692 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2693 * values from/to the user buffer, treated as an ASCII string.
2694 * The values read are assumed to be in seconds, and are converted into
2695 * jiffies.
2697 * Returns 0 on success.
2699 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2700 void __user *buffer, size_t *lenp, loff_t *ppos)
2702 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2703 do_proc_dointvec_jiffies_conv,NULL);
2707 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2708 * @table: the sysctl table
2709 * @write: %TRUE if this is a write to the sysctl file
2710 * @buffer: the user buffer
2711 * @lenp: the size of the user buffer
2712 * @ppos: pointer to the file position
2714 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715 * values from/to the user buffer, treated as an ASCII string.
2716 * The values read are assumed to be in 1/USER_HZ seconds, and
2717 * are converted into jiffies.
2719 * Returns 0 on success.
2721 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2722 void __user *buffer, size_t *lenp, loff_t *ppos)
2724 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2725 do_proc_dointvec_userhz_jiffies_conv,NULL);
2729 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2730 * @table: the sysctl table
2731 * @write: %TRUE if this is a write to the sysctl file
2732 * @buffer: the user buffer
2733 * @lenp: the size of the user buffer
2734 * @ppos: file position
2735 * @ppos: the current position in the file
2737 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2738 * values from/to the user buffer, treated as an ASCII string.
2739 * The values read are assumed to be in 1/1000 seconds, and
2740 * are converted into jiffies.
2742 * Returns 0 on success.
2744 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2745 void __user *buffer, size_t *lenp, loff_t *ppos)
2747 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2748 do_proc_dointvec_ms_jiffies_conv, NULL);
2751 static int proc_do_cad_pid(struct ctl_table *table, int write,
2752 void __user *buffer, size_t *lenp, loff_t *ppos)
2754 struct pid *new_pid;
2755 pid_t tmp;
2756 int r;
2758 tmp = pid_vnr(cad_pid);
2760 r = __do_proc_dointvec(&tmp, table, write, buffer,
2761 lenp, ppos, NULL, NULL);
2762 if (r || !write)
2763 return r;
2765 new_pid = find_get_pid(tmp);
2766 if (!new_pid)
2767 return -ESRCH;
2769 put_pid(xchg(&cad_pid, new_pid));
2770 return 0;
2774 * proc_do_large_bitmap - read/write from/to a large bitmap
2775 * @table: the sysctl table
2776 * @write: %TRUE if this is a write to the sysctl file
2777 * @buffer: the user buffer
2778 * @lenp: the size of the user buffer
2779 * @ppos: file position
2781 * The bitmap is stored at table->data and the bitmap length (in bits)
2782 * in table->maxlen.
2784 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2785 * large bitmaps may be represented in a compact manner. Writing into
2786 * the file will clear the bitmap then update it with the given input.
2788 * Returns 0 on success.
2790 int proc_do_large_bitmap(struct ctl_table *table, int write,
2791 void __user *buffer, size_t *lenp, loff_t *ppos)
2793 int err = 0;
2794 bool first = 1;
2795 size_t left = *lenp;
2796 unsigned long bitmap_len = table->maxlen;
2797 unsigned long *bitmap = (unsigned long *) table->data;
2798 unsigned long *tmp_bitmap = NULL;
2799 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2801 if (!bitmap_len || !left || (*ppos && !write)) {
2802 *lenp = 0;
2803 return 0;
2806 if (write) {
2807 unsigned long page = 0;
2808 char *kbuf;
2810 if (left > PAGE_SIZE - 1)
2811 left = PAGE_SIZE - 1;
2813 page = __get_free_page(GFP_TEMPORARY);
2814 kbuf = (char *) page;
2815 if (!kbuf)
2816 return -ENOMEM;
2817 if (copy_from_user(kbuf, buffer, left)) {
2818 free_page(page);
2819 return -EFAULT;
2821 kbuf[left] = 0;
2823 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2824 GFP_KERNEL);
2825 if (!tmp_bitmap) {
2826 free_page(page);
2827 return -ENOMEM;
2829 proc_skip_char(&kbuf, &left, '\n');
2830 while (!err && left) {
2831 unsigned long val_a, val_b;
2832 bool neg;
2834 err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2835 sizeof(tr_a), &c);
2836 if (err)
2837 break;
2838 if (val_a >= bitmap_len || neg) {
2839 err = -EINVAL;
2840 break;
2843 val_b = val_a;
2844 if (left) {
2845 kbuf++;
2846 left--;
2849 if (c == '-') {
2850 err = proc_get_long(&kbuf, &left, &val_b,
2851 &neg, tr_b, sizeof(tr_b),
2852 &c);
2853 if (err)
2854 break;
2855 if (val_b >= bitmap_len || neg ||
2856 val_a > val_b) {
2857 err = -EINVAL;
2858 break;
2860 if (left) {
2861 kbuf++;
2862 left--;
2866 while (val_a <= val_b)
2867 set_bit(val_a++, tmp_bitmap);
2869 first = 0;
2870 proc_skip_char(&kbuf, &left, '\n');
2872 free_page(page);
2873 } else {
2874 unsigned long bit_a, bit_b = 0;
2876 while (left) {
2877 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2878 if (bit_a >= bitmap_len)
2879 break;
2880 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2881 bit_a + 1) - 1;
2883 if (!first) {
2884 err = proc_put_char(&buffer, &left, ',');
2885 if (err)
2886 break;
2888 err = proc_put_long(&buffer, &left, bit_a, false);
2889 if (err)
2890 break;
2891 if (bit_a != bit_b) {
2892 err = proc_put_char(&buffer, &left, '-');
2893 if (err)
2894 break;
2895 err = proc_put_long(&buffer, &left, bit_b, false);
2896 if (err)
2897 break;
2900 first = 0; bit_b++;
2902 if (!err)
2903 err = proc_put_char(&buffer, &left, '\n');
2906 if (!err) {
2907 if (write) {
2908 if (*ppos)
2909 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2910 else
2911 memcpy(bitmap, tmp_bitmap,
2912 BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2914 kfree(tmp_bitmap);
2915 *lenp -= left;
2916 *ppos += *lenp;
2917 return 0;
2918 } else {
2919 kfree(tmp_bitmap);
2920 return err;
2924 #else /* CONFIG_PROC_SYSCTL */
2926 int proc_dostring(struct ctl_table *table, int write,
2927 void __user *buffer, size_t *lenp, loff_t *ppos)
2929 return -ENOSYS;
2932 int proc_dointvec(struct ctl_table *table, int write,
2933 void __user *buffer, size_t *lenp, loff_t *ppos)
2935 return -ENOSYS;
2938 int proc_dointvec_minmax(struct ctl_table *table, int write,
2939 void __user *buffer, size_t *lenp, loff_t *ppos)
2941 return -ENOSYS;
2944 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2945 void __user *buffer, size_t *lenp, loff_t *ppos)
2947 return -ENOSYS;
2950 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2951 void __user *buffer, size_t *lenp, loff_t *ppos)
2953 return -ENOSYS;
2956 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2957 void __user *buffer, size_t *lenp, loff_t *ppos)
2959 return -ENOSYS;
2962 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2963 void __user *buffer, size_t *lenp, loff_t *ppos)
2965 return -ENOSYS;
2968 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2969 void __user *buffer,
2970 size_t *lenp, loff_t *ppos)
2972 return -ENOSYS;
2976 #endif /* CONFIG_PROC_SYSCTL */
2979 * No sense putting this after each symbol definition, twice,
2980 * exception granted :-)
2982 EXPORT_SYMBOL(proc_dointvec);
2983 EXPORT_SYMBOL(proc_dointvec_jiffies);
2984 EXPORT_SYMBOL(proc_dointvec_minmax);
2985 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2986 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2987 EXPORT_SYMBOL(proc_dostring);
2988 EXPORT_SYMBOL(proc_doulongvec_minmax);
2989 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2990 EXPORT_SYMBOL(register_sysctl_table);
2991 EXPORT_SYMBOL(register_sysctl_paths);
2992 EXPORT_SYMBOL(unregister_sysctl_table);