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[linux-2.6/next.git] / kernel / sysctl.c
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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 * User-space scripts rely on the existence of this file
943 * as a feature check for perf_events being enabled.
945 * So it's an ABI, do not remove!
948 .procname = "perf_event_paranoid",
949 .data = &sysctl_perf_event_paranoid,
950 .maxlen = sizeof(sysctl_perf_event_paranoid),
951 .mode = 0644,
952 .proc_handler = proc_dointvec,
955 .procname = "perf_event_mlock_kb",
956 .data = &sysctl_perf_event_mlock,
957 .maxlen = sizeof(sysctl_perf_event_mlock),
958 .mode = 0644,
959 .proc_handler = proc_dointvec,
962 .procname = "perf_event_max_sample_rate",
963 .data = &sysctl_perf_event_sample_rate,
964 .maxlen = sizeof(sysctl_perf_event_sample_rate),
965 .mode = 0644,
966 .proc_handler = perf_proc_update_handler,
968 #endif
969 #ifdef CONFIG_KMEMCHECK
971 .procname = "kmemcheck",
972 .data = &kmemcheck_enabled,
973 .maxlen = sizeof(int),
974 .mode = 0644,
975 .proc_handler = proc_dointvec,
977 #endif
978 #ifdef CONFIG_BLOCK
980 .procname = "blk_iopoll",
981 .data = &blk_iopoll_enabled,
982 .maxlen = sizeof(int),
983 .mode = 0644,
984 .proc_handler = proc_dointvec,
986 #endif
990 static struct ctl_table vm_table[] = {
992 .procname = "overcommit_memory",
993 .data = &sysctl_overcommit_memory,
994 .maxlen = sizeof(sysctl_overcommit_memory),
995 .mode = 0644,
996 .proc_handler = proc_dointvec_minmax,
997 .extra1 = &zero,
998 .extra2 = &two,
1001 .procname = "panic_on_oom",
1002 .data = &sysctl_panic_on_oom,
1003 .maxlen = sizeof(sysctl_panic_on_oom),
1004 .mode = 0644,
1005 .proc_handler = proc_dointvec_minmax,
1006 .extra1 = &zero,
1007 .extra2 = &two,
1010 .procname = "oom_kill_allocating_task",
1011 .data = &sysctl_oom_kill_allocating_task,
1012 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1013 .mode = 0644,
1014 .proc_handler = proc_dointvec,
1017 .procname = "oom_dump_tasks",
1018 .data = &sysctl_oom_dump_tasks,
1019 .maxlen = sizeof(sysctl_oom_dump_tasks),
1020 .mode = 0644,
1021 .proc_handler = proc_dointvec,
1024 .procname = "overcommit_ratio",
1025 .data = &sysctl_overcommit_ratio,
1026 .maxlen = sizeof(sysctl_overcommit_ratio),
1027 .mode = 0644,
1028 .proc_handler = proc_dointvec,
1031 .procname = "page-cluster",
1032 .data = &page_cluster,
1033 .maxlen = sizeof(int),
1034 .mode = 0644,
1035 .proc_handler = proc_dointvec_minmax,
1036 .extra1 = &zero,
1039 .procname = "dirty_background_ratio",
1040 .data = &dirty_background_ratio,
1041 .maxlen = sizeof(dirty_background_ratio),
1042 .mode = 0644,
1043 .proc_handler = dirty_background_ratio_handler,
1044 .extra1 = &zero,
1045 .extra2 = &one_hundred,
1048 .procname = "dirty_background_bytes",
1049 .data = &dirty_background_bytes,
1050 .maxlen = sizeof(dirty_background_bytes),
1051 .mode = 0644,
1052 .proc_handler = dirty_background_bytes_handler,
1053 .extra1 = &one_ul,
1056 .procname = "dirty_ratio",
1057 .data = &vm_dirty_ratio,
1058 .maxlen = sizeof(vm_dirty_ratio),
1059 .mode = 0644,
1060 .proc_handler = dirty_ratio_handler,
1061 .extra1 = &zero,
1062 .extra2 = &one_hundred,
1065 .procname = "dirty_bytes",
1066 .data = &vm_dirty_bytes,
1067 .maxlen = sizeof(vm_dirty_bytes),
1068 .mode = 0644,
1069 .proc_handler = dirty_bytes_handler,
1070 .extra1 = &dirty_bytes_min,
1073 .procname = "dirty_writeback_centisecs",
1074 .data = &dirty_writeback_interval,
1075 .maxlen = sizeof(dirty_writeback_interval),
1076 .mode = 0644,
1077 .proc_handler = dirty_writeback_centisecs_handler,
1080 .procname = "dirty_expire_centisecs",
1081 .data = &dirty_expire_interval,
1082 .maxlen = sizeof(dirty_expire_interval),
1083 .mode = 0644,
1084 .proc_handler = proc_dointvec_minmax,
1085 .extra1 = &zero,
1088 .procname = "nr_pdflush_threads",
1089 .data = &nr_pdflush_threads,
1090 .maxlen = sizeof nr_pdflush_threads,
1091 .mode = 0444 /* read-only*/,
1092 .proc_handler = proc_dointvec,
1095 .procname = "swappiness",
1096 .data = &vm_swappiness,
1097 .maxlen = sizeof(vm_swappiness),
1098 .mode = 0644,
1099 .proc_handler = proc_dointvec_minmax,
1100 .extra1 = &zero,
1101 .extra2 = &one_hundred,
1103 #ifdef CONFIG_HUGETLB_PAGE
1105 .procname = "nr_hugepages",
1106 .data = NULL,
1107 .maxlen = sizeof(unsigned long),
1108 .mode = 0644,
1109 .proc_handler = hugetlb_sysctl_handler,
1110 .extra1 = (void *)&hugetlb_zero,
1111 .extra2 = (void *)&hugetlb_infinity,
1113 #ifdef CONFIG_NUMA
1115 .procname = "nr_hugepages_mempolicy",
1116 .data = NULL,
1117 .maxlen = sizeof(unsigned long),
1118 .mode = 0644,
1119 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1120 .extra1 = (void *)&hugetlb_zero,
1121 .extra2 = (void *)&hugetlb_infinity,
1123 #endif
1125 .procname = "hugetlb_shm_group",
1126 .data = &sysctl_hugetlb_shm_group,
1127 .maxlen = sizeof(gid_t),
1128 .mode = 0644,
1129 .proc_handler = proc_dointvec,
1132 .procname = "hugepages_treat_as_movable",
1133 .data = &hugepages_treat_as_movable,
1134 .maxlen = sizeof(int),
1135 .mode = 0644,
1136 .proc_handler = hugetlb_treat_movable_handler,
1139 .procname = "nr_overcommit_hugepages",
1140 .data = NULL,
1141 .maxlen = sizeof(unsigned long),
1142 .mode = 0644,
1143 .proc_handler = hugetlb_overcommit_handler,
1144 .extra1 = (void *)&hugetlb_zero,
1145 .extra2 = (void *)&hugetlb_infinity,
1147 #endif
1149 .procname = "lowmem_reserve_ratio",
1150 .data = &sysctl_lowmem_reserve_ratio,
1151 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1152 .mode = 0644,
1153 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1156 .procname = "drop_caches",
1157 .data = &sysctl_drop_caches,
1158 .maxlen = sizeof(int),
1159 .mode = 0644,
1160 .proc_handler = drop_caches_sysctl_handler,
1161 .extra1 = &one,
1162 .extra2 = &three,
1164 #ifdef CONFIG_COMPACTION
1166 .procname = "compact_memory",
1167 .data = &sysctl_compact_memory,
1168 .maxlen = sizeof(int),
1169 .mode = 0200,
1170 .proc_handler = sysctl_compaction_handler,
1173 .procname = "extfrag_threshold",
1174 .data = &sysctl_extfrag_threshold,
1175 .maxlen = sizeof(int),
1176 .mode = 0644,
1177 .proc_handler = sysctl_extfrag_handler,
1178 .extra1 = &min_extfrag_threshold,
1179 .extra2 = &max_extfrag_threshold,
1182 #endif /* CONFIG_COMPACTION */
1184 .procname = "min_free_kbytes",
1185 .data = &min_free_kbytes,
1186 .maxlen = sizeof(min_free_kbytes),
1187 .mode = 0644,
1188 .proc_handler = min_free_kbytes_sysctl_handler,
1189 .extra1 = &zero,
1192 .procname = "percpu_pagelist_fraction",
1193 .data = &percpu_pagelist_fraction,
1194 .maxlen = sizeof(percpu_pagelist_fraction),
1195 .mode = 0644,
1196 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1197 .extra1 = &min_percpu_pagelist_fract,
1199 #ifdef CONFIG_MMU
1201 .procname = "max_map_count",
1202 .data = &sysctl_max_map_count,
1203 .maxlen = sizeof(sysctl_max_map_count),
1204 .mode = 0644,
1205 .proc_handler = proc_dointvec_minmax,
1206 .extra1 = &zero,
1208 #else
1210 .procname = "nr_trim_pages",
1211 .data = &sysctl_nr_trim_pages,
1212 .maxlen = sizeof(sysctl_nr_trim_pages),
1213 .mode = 0644,
1214 .proc_handler = proc_dointvec_minmax,
1215 .extra1 = &zero,
1217 #endif
1219 .procname = "laptop_mode",
1220 .data = &laptop_mode,
1221 .maxlen = sizeof(laptop_mode),
1222 .mode = 0644,
1223 .proc_handler = proc_dointvec_jiffies,
1226 .procname = "block_dump",
1227 .data = &block_dump,
1228 .maxlen = sizeof(block_dump),
1229 .mode = 0644,
1230 .proc_handler = proc_dointvec,
1231 .extra1 = &zero,
1234 .procname = "vfs_cache_pressure",
1235 .data = &sysctl_vfs_cache_pressure,
1236 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1237 .mode = 0644,
1238 .proc_handler = proc_dointvec,
1239 .extra1 = &zero,
1241 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1243 .procname = "legacy_va_layout",
1244 .data = &sysctl_legacy_va_layout,
1245 .maxlen = sizeof(sysctl_legacy_va_layout),
1246 .mode = 0644,
1247 .proc_handler = proc_dointvec,
1248 .extra1 = &zero,
1250 #endif
1251 #ifdef CONFIG_NUMA
1253 .procname = "zone_reclaim_mode",
1254 .data = &zone_reclaim_mode,
1255 .maxlen = sizeof(zone_reclaim_mode),
1256 .mode = 0644,
1257 .proc_handler = proc_dointvec,
1258 .extra1 = &zero,
1261 .procname = "min_unmapped_ratio",
1262 .data = &sysctl_min_unmapped_ratio,
1263 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1264 .mode = 0644,
1265 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1266 .extra1 = &zero,
1267 .extra2 = &one_hundred,
1270 .procname = "min_slab_ratio",
1271 .data = &sysctl_min_slab_ratio,
1272 .maxlen = sizeof(sysctl_min_slab_ratio),
1273 .mode = 0644,
1274 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1275 .extra1 = &zero,
1276 .extra2 = &one_hundred,
1278 #endif
1279 #ifdef CONFIG_SMP
1281 .procname = "stat_interval",
1282 .data = &sysctl_stat_interval,
1283 .maxlen = sizeof(sysctl_stat_interval),
1284 .mode = 0644,
1285 .proc_handler = proc_dointvec_jiffies,
1287 #endif
1288 #ifdef CONFIG_MMU
1290 .procname = "mmap_min_addr",
1291 .data = &dac_mmap_min_addr,
1292 .maxlen = sizeof(unsigned long),
1293 .mode = 0644,
1294 .proc_handler = mmap_min_addr_handler,
1296 #endif
1297 #ifdef CONFIG_NUMA
1299 .procname = "numa_zonelist_order",
1300 .data = &numa_zonelist_order,
1301 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1302 .mode = 0644,
1303 .proc_handler = numa_zonelist_order_handler,
1305 #endif
1306 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1307 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1309 .procname = "vdso_enabled",
1310 .data = &vdso_enabled,
1311 .maxlen = sizeof(vdso_enabled),
1312 .mode = 0644,
1313 .proc_handler = proc_dointvec,
1314 .extra1 = &zero,
1316 #endif
1317 #ifdef CONFIG_HIGHMEM
1319 .procname = "highmem_is_dirtyable",
1320 .data = &vm_highmem_is_dirtyable,
1321 .maxlen = sizeof(vm_highmem_is_dirtyable),
1322 .mode = 0644,
1323 .proc_handler = proc_dointvec_minmax,
1324 .extra1 = &zero,
1325 .extra2 = &one,
1327 #endif
1329 .procname = "scan_unevictable_pages",
1330 .data = &scan_unevictable_pages,
1331 .maxlen = sizeof(scan_unevictable_pages),
1332 .mode = 0644,
1333 .proc_handler = scan_unevictable_handler,
1335 #ifdef CONFIG_MEMORY_FAILURE
1337 .procname = "memory_failure_early_kill",
1338 .data = &sysctl_memory_failure_early_kill,
1339 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1340 .mode = 0644,
1341 .proc_handler = proc_dointvec_minmax,
1342 .extra1 = &zero,
1343 .extra2 = &one,
1346 .procname = "memory_failure_recovery",
1347 .data = &sysctl_memory_failure_recovery,
1348 .maxlen = sizeof(sysctl_memory_failure_recovery),
1349 .mode = 0644,
1350 .proc_handler = proc_dointvec_minmax,
1351 .extra1 = &zero,
1352 .extra2 = &one,
1354 #endif
1358 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1359 static struct ctl_table binfmt_misc_table[] = {
1362 #endif
1364 static struct ctl_table fs_table[] = {
1366 .procname = "inode-nr",
1367 .data = &inodes_stat,
1368 .maxlen = 2*sizeof(int),
1369 .mode = 0444,
1370 .proc_handler = proc_nr_inodes,
1373 .procname = "inode-state",
1374 .data = &inodes_stat,
1375 .maxlen = 7*sizeof(int),
1376 .mode = 0444,
1377 .proc_handler = proc_nr_inodes,
1380 .procname = "file-nr",
1381 .data = &files_stat,
1382 .maxlen = sizeof(files_stat),
1383 .mode = 0444,
1384 .proc_handler = proc_nr_files,
1387 .procname = "file-max",
1388 .data = &files_stat.max_files,
1389 .maxlen = sizeof(files_stat.max_files),
1390 .mode = 0644,
1391 .proc_handler = proc_doulongvec_minmax,
1394 .procname = "nr_open",
1395 .data = &sysctl_nr_open,
1396 .maxlen = sizeof(int),
1397 .mode = 0644,
1398 .proc_handler = proc_dointvec_minmax,
1399 .extra1 = &sysctl_nr_open_min,
1400 .extra2 = &sysctl_nr_open_max,
1403 .procname = "dentry-state",
1404 .data = &dentry_stat,
1405 .maxlen = 6*sizeof(int),
1406 .mode = 0444,
1407 .proc_handler = proc_nr_dentry,
1410 .procname = "overflowuid",
1411 .data = &fs_overflowuid,
1412 .maxlen = sizeof(int),
1413 .mode = 0644,
1414 .proc_handler = proc_dointvec_minmax,
1415 .extra1 = &minolduid,
1416 .extra2 = &maxolduid,
1419 .procname = "overflowgid",
1420 .data = &fs_overflowgid,
1421 .maxlen = sizeof(int),
1422 .mode = 0644,
1423 .proc_handler = proc_dointvec_minmax,
1424 .extra1 = &minolduid,
1425 .extra2 = &maxolduid,
1427 #ifdef CONFIG_FILE_LOCKING
1429 .procname = "leases-enable",
1430 .data = &leases_enable,
1431 .maxlen = sizeof(int),
1432 .mode = 0644,
1433 .proc_handler = proc_dointvec,
1435 #endif
1436 #ifdef CONFIG_DNOTIFY
1438 .procname = "dir-notify-enable",
1439 .data = &dir_notify_enable,
1440 .maxlen = sizeof(int),
1441 .mode = 0644,
1442 .proc_handler = proc_dointvec,
1444 #endif
1445 #ifdef CONFIG_MMU
1446 #ifdef CONFIG_FILE_LOCKING
1448 .procname = "lease-break-time",
1449 .data = &lease_break_time,
1450 .maxlen = sizeof(int),
1451 .mode = 0644,
1452 .proc_handler = proc_dointvec,
1454 #endif
1455 #ifdef CONFIG_AIO
1457 .procname = "aio-nr",
1458 .data = &aio_nr,
1459 .maxlen = sizeof(aio_nr),
1460 .mode = 0444,
1461 .proc_handler = proc_doulongvec_minmax,
1464 .procname = "aio-max-nr",
1465 .data = &aio_max_nr,
1466 .maxlen = sizeof(aio_max_nr),
1467 .mode = 0644,
1468 .proc_handler = proc_doulongvec_minmax,
1470 #endif /* CONFIG_AIO */
1471 #ifdef CONFIG_INOTIFY_USER
1473 .procname = "inotify",
1474 .mode = 0555,
1475 .child = inotify_table,
1477 #endif
1478 #ifdef CONFIG_EPOLL
1480 .procname = "epoll",
1481 .mode = 0555,
1482 .child = epoll_table,
1484 #endif
1485 #endif
1487 .procname = "suid_dumpable",
1488 .data = &suid_dumpable,
1489 .maxlen = sizeof(int),
1490 .mode = 0644,
1491 .proc_handler = proc_dointvec_minmax,
1492 .extra1 = &zero,
1493 .extra2 = &two,
1495 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1497 .procname = "binfmt_misc",
1498 .mode = 0555,
1499 .child = binfmt_misc_table,
1501 #endif
1503 .procname = "pipe-max-size",
1504 .data = &pipe_max_size,
1505 .maxlen = sizeof(int),
1506 .mode = 0644,
1507 .proc_handler = &pipe_proc_fn,
1508 .extra1 = &pipe_min_size,
1513 static struct ctl_table debug_table[] = {
1514 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1515 defined(CONFIG_S390) || defined(CONFIG_TILE)
1517 .procname = "exception-trace",
1518 .data = &show_unhandled_signals,
1519 .maxlen = sizeof(int),
1520 .mode = 0644,
1521 .proc_handler = proc_dointvec
1523 #endif
1524 #if defined(CONFIG_OPTPROBES)
1526 .procname = "kprobes-optimization",
1527 .data = &sysctl_kprobes_optimization,
1528 .maxlen = sizeof(int),
1529 .mode = 0644,
1530 .proc_handler = proc_kprobes_optimization_handler,
1531 .extra1 = &zero,
1532 .extra2 = &one,
1534 #endif
1538 static struct ctl_table dev_table[] = {
1542 static DEFINE_SPINLOCK(sysctl_lock);
1544 /* called under sysctl_lock */
1545 static int use_table(struct ctl_table_header *p)
1547 if (unlikely(p->unregistering))
1548 return 0;
1549 p->used++;
1550 return 1;
1553 /* called under sysctl_lock */
1554 static void unuse_table(struct ctl_table_header *p)
1556 if (!--p->used)
1557 if (unlikely(p->unregistering))
1558 complete(p->unregistering);
1561 /* called under sysctl_lock, will reacquire if has to wait */
1562 static void start_unregistering(struct ctl_table_header *p)
1565 * if p->used is 0, nobody will ever touch that entry again;
1566 * we'll eliminate all paths to it before dropping sysctl_lock
1568 if (unlikely(p->used)) {
1569 struct completion wait;
1570 init_completion(&wait);
1571 p->unregistering = &wait;
1572 spin_unlock(&sysctl_lock);
1573 wait_for_completion(&wait);
1574 spin_lock(&sysctl_lock);
1575 } else {
1576 /* anything non-NULL; we'll never dereference it */
1577 p->unregistering = ERR_PTR(-EINVAL);
1580 * do not remove from the list until nobody holds it; walking the
1581 * list in do_sysctl() relies on that.
1583 list_del_init(&p->ctl_entry);
1586 void sysctl_head_get(struct ctl_table_header *head)
1588 spin_lock(&sysctl_lock);
1589 head->count++;
1590 spin_unlock(&sysctl_lock);
1593 static void free_head(struct rcu_head *rcu)
1595 kfree(container_of(rcu, struct ctl_table_header, rcu));
1598 void sysctl_head_put(struct ctl_table_header *head)
1600 spin_lock(&sysctl_lock);
1601 if (!--head->count)
1602 call_rcu(&head->rcu, free_head);
1603 spin_unlock(&sysctl_lock);
1606 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1608 if (!head)
1609 BUG();
1610 spin_lock(&sysctl_lock);
1611 if (!use_table(head))
1612 head = ERR_PTR(-ENOENT);
1613 spin_unlock(&sysctl_lock);
1614 return head;
1617 void sysctl_head_finish(struct ctl_table_header *head)
1619 if (!head)
1620 return;
1621 spin_lock(&sysctl_lock);
1622 unuse_table(head);
1623 spin_unlock(&sysctl_lock);
1626 static struct ctl_table_set *
1627 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1629 struct ctl_table_set *set = &root->default_set;
1630 if (root->lookup)
1631 set = root->lookup(root, namespaces);
1632 return set;
1635 static struct list_head *
1636 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1638 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1639 return &set->list;
1642 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1643 struct ctl_table_header *prev)
1645 struct ctl_table_root *root;
1646 struct list_head *header_list;
1647 struct ctl_table_header *head;
1648 struct list_head *tmp;
1650 spin_lock(&sysctl_lock);
1651 if (prev) {
1652 head = prev;
1653 tmp = &prev->ctl_entry;
1654 unuse_table(prev);
1655 goto next;
1657 tmp = &root_table_header.ctl_entry;
1658 for (;;) {
1659 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1661 if (!use_table(head))
1662 goto next;
1663 spin_unlock(&sysctl_lock);
1664 return head;
1665 next:
1666 root = head->root;
1667 tmp = tmp->next;
1668 header_list = lookup_header_list(root, namespaces);
1669 if (tmp != header_list)
1670 continue;
1672 do {
1673 root = list_entry(root->root_list.next,
1674 struct ctl_table_root, root_list);
1675 if (root == &sysctl_table_root)
1676 goto out;
1677 header_list = lookup_header_list(root, namespaces);
1678 } while (list_empty(header_list));
1679 tmp = header_list->next;
1681 out:
1682 spin_unlock(&sysctl_lock);
1683 return NULL;
1686 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1688 return __sysctl_head_next(current->nsproxy, prev);
1691 void register_sysctl_root(struct ctl_table_root *root)
1693 spin_lock(&sysctl_lock);
1694 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1695 spin_unlock(&sysctl_lock);
1699 * sysctl_perm does NOT grant the superuser all rights automatically, because
1700 * some sysctl variables are readonly even to root.
1703 static int test_perm(int mode, int op)
1705 if (!current_euid())
1706 mode >>= 6;
1707 else if (in_egroup_p(0))
1708 mode >>= 3;
1709 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1710 return 0;
1711 return -EACCES;
1714 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1716 int mode;
1718 if (root->permissions)
1719 mode = root->permissions(root, current->nsproxy, table);
1720 else
1721 mode = table->mode;
1723 return test_perm(mode, op);
1726 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1728 for (; table->procname; table++) {
1729 table->parent = parent;
1730 if (table->child)
1731 sysctl_set_parent(table, table->child);
1735 static __init int sysctl_init(void)
1737 sysctl_set_parent(NULL, root_table);
1738 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1739 sysctl_check_table(current->nsproxy, root_table);
1740 #endif
1741 return 0;
1744 core_initcall(sysctl_init);
1746 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1747 struct ctl_table *table)
1749 struct ctl_table *p;
1750 const char *s = branch->procname;
1752 /* branch should have named subdirectory as its first element */
1753 if (!s || !branch->child)
1754 return NULL;
1756 /* ... and nothing else */
1757 if (branch[1].procname)
1758 return NULL;
1760 /* table should contain subdirectory with the same name */
1761 for (p = table; p->procname; p++) {
1762 if (!p->child)
1763 continue;
1764 if (p->procname && strcmp(p->procname, s) == 0)
1765 return p;
1767 return NULL;
1770 /* see if attaching q to p would be an improvement */
1771 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1773 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1774 struct ctl_table *next;
1775 int is_better = 0;
1776 int not_in_parent = !p->attached_by;
1778 while ((next = is_branch_in(by, to)) != NULL) {
1779 if (by == q->attached_by)
1780 is_better = 1;
1781 if (to == p->attached_by)
1782 not_in_parent = 1;
1783 by = by->child;
1784 to = next->child;
1787 if (is_better && not_in_parent) {
1788 q->attached_by = by;
1789 q->attached_to = to;
1790 q->parent = p;
1795 * __register_sysctl_paths - register a sysctl hierarchy
1796 * @root: List of sysctl headers to register on
1797 * @namespaces: Data to compute which lists of sysctl entries are visible
1798 * @path: The path to the directory the sysctl table is in.
1799 * @table: the top-level table structure
1801 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1802 * array. A completely 0 filled entry terminates the table.
1804 * The members of the &struct ctl_table structure are used as follows:
1806 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1807 * enter a sysctl file
1809 * data - a pointer to data for use by proc_handler
1811 * maxlen - the maximum size in bytes of the data
1813 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1815 * child - a pointer to the child sysctl table if this entry is a directory, or
1816 * %NULL.
1818 * proc_handler - the text handler routine (described below)
1820 * de - for internal use by the sysctl routines
1822 * extra1, extra2 - extra pointers usable by the proc handler routines
1824 * Leaf nodes in the sysctl tree will be represented by a single file
1825 * under /proc; non-leaf nodes will be represented by directories.
1827 * sysctl(2) can automatically manage read and write requests through
1828 * the sysctl table. The data and maxlen fields of the ctl_table
1829 * struct enable minimal validation of the values being written to be
1830 * performed, and the mode field allows minimal authentication.
1832 * There must be a proc_handler routine for any terminal nodes
1833 * mirrored under /proc/sys (non-terminals are handled by a built-in
1834 * directory handler). Several default handlers are available to
1835 * cover common cases -
1837 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1838 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1839 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1841 * It is the handler's job to read the input buffer from user memory
1842 * and process it. The handler should return 0 on success.
1844 * This routine returns %NULL on a failure to register, and a pointer
1845 * to the table header on success.
1847 struct ctl_table_header *__register_sysctl_paths(
1848 struct ctl_table_root *root,
1849 struct nsproxy *namespaces,
1850 const struct ctl_path *path, struct ctl_table *table)
1852 struct ctl_table_header *header;
1853 struct ctl_table *new, **prevp;
1854 unsigned int n, npath;
1855 struct ctl_table_set *set;
1857 /* Count the path components */
1858 for (npath = 0; path[npath].procname; ++npath)
1862 * For each path component, allocate a 2-element ctl_table array.
1863 * The first array element will be filled with the sysctl entry
1864 * for this, the second will be the sentinel (procname == 0).
1866 * We allocate everything in one go so that we don't have to
1867 * worry about freeing additional memory in unregister_sysctl_table.
1869 header = kzalloc(sizeof(struct ctl_table_header) +
1870 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1871 if (!header)
1872 return NULL;
1874 new = (struct ctl_table *) (header + 1);
1876 /* Now connect the dots */
1877 prevp = &header->ctl_table;
1878 for (n = 0; n < npath; ++n, ++path) {
1879 /* Copy the procname */
1880 new->procname = path->procname;
1881 new->mode = 0555;
1883 *prevp = new;
1884 prevp = &new->child;
1886 new += 2;
1888 *prevp = table;
1889 header->ctl_table_arg = table;
1891 INIT_LIST_HEAD(&header->ctl_entry);
1892 header->used = 0;
1893 header->unregistering = NULL;
1894 header->root = root;
1895 sysctl_set_parent(NULL, header->ctl_table);
1896 header->count = 1;
1897 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1898 if (sysctl_check_table(namespaces, header->ctl_table)) {
1899 kfree(header);
1900 return NULL;
1902 #endif
1903 spin_lock(&sysctl_lock);
1904 header->set = lookup_header_set(root, namespaces);
1905 header->attached_by = header->ctl_table;
1906 header->attached_to = root_table;
1907 header->parent = &root_table_header;
1908 for (set = header->set; set; set = set->parent) {
1909 struct ctl_table_header *p;
1910 list_for_each_entry(p, &set->list, ctl_entry) {
1911 if (p->unregistering)
1912 continue;
1913 try_attach(p, header);
1916 header->parent->count++;
1917 list_add_tail(&header->ctl_entry, &header->set->list);
1918 spin_unlock(&sysctl_lock);
1920 return header;
1924 * register_sysctl_table_path - register a sysctl table hierarchy
1925 * @path: The path to the directory the sysctl table is in.
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_paths(const struct ctl_path *path,
1934 struct ctl_table *table)
1936 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1937 path, table);
1941 * register_sysctl_table - register a sysctl table hierarchy
1942 * @table: the top-level table structure
1944 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1945 * array. A completely 0 filled entry terminates the table.
1947 * See register_sysctl_paths for more details.
1949 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1951 static const struct ctl_path null_path[] = { {} };
1953 return register_sysctl_paths(null_path, table);
1957 * unregister_sysctl_table - unregister a sysctl table hierarchy
1958 * @header: the header returned from register_sysctl_table
1960 * Unregisters the sysctl table and all children. proc entries may not
1961 * actually be removed until they are no longer used by anyone.
1963 void unregister_sysctl_table(struct ctl_table_header * header)
1965 might_sleep();
1967 if (header == NULL)
1968 return;
1970 spin_lock(&sysctl_lock);
1971 start_unregistering(header);
1972 if (!--header->parent->count) {
1973 WARN_ON(1);
1974 call_rcu(&header->parent->rcu, free_head);
1976 if (!--header->count)
1977 call_rcu(&header->rcu, free_head);
1978 spin_unlock(&sysctl_lock);
1981 int sysctl_is_seen(struct ctl_table_header *p)
1983 struct ctl_table_set *set = p->set;
1984 int res;
1985 spin_lock(&sysctl_lock);
1986 if (p->unregistering)
1987 res = 0;
1988 else if (!set->is_seen)
1989 res = 1;
1990 else
1991 res = set->is_seen(set);
1992 spin_unlock(&sysctl_lock);
1993 return res;
1996 void setup_sysctl_set(struct ctl_table_set *p,
1997 struct ctl_table_set *parent,
1998 int (*is_seen)(struct ctl_table_set *))
2000 INIT_LIST_HEAD(&p->list);
2001 p->parent = parent ? parent : &sysctl_table_root.default_set;
2002 p->is_seen = is_seen;
2005 #else /* !CONFIG_SYSCTL */
2006 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2008 return NULL;
2011 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2012 struct ctl_table *table)
2014 return NULL;
2017 void unregister_sysctl_table(struct ctl_table_header * table)
2021 void setup_sysctl_set(struct ctl_table_set *p,
2022 struct ctl_table_set *parent,
2023 int (*is_seen)(struct ctl_table_set *))
2027 void sysctl_head_put(struct ctl_table_header *head)
2031 #endif /* CONFIG_SYSCTL */
2034 * /proc/sys support
2037 #ifdef CONFIG_PROC_SYSCTL
2039 static int _proc_do_string(void* data, int maxlen, int write,
2040 void __user *buffer,
2041 size_t *lenp, loff_t *ppos)
2043 size_t len;
2044 char __user *p;
2045 char c;
2047 if (!data || !maxlen || !*lenp) {
2048 *lenp = 0;
2049 return 0;
2052 if (write) {
2053 len = 0;
2054 p = buffer;
2055 while (len < *lenp) {
2056 if (get_user(c, p++))
2057 return -EFAULT;
2058 if (c == 0 || c == '\n')
2059 break;
2060 len++;
2062 if (len >= maxlen)
2063 len = maxlen-1;
2064 if(copy_from_user(data, buffer, len))
2065 return -EFAULT;
2066 ((char *) data)[len] = 0;
2067 *ppos += *lenp;
2068 } else {
2069 len = strlen(data);
2070 if (len > maxlen)
2071 len = maxlen;
2073 if (*ppos > len) {
2074 *lenp = 0;
2075 return 0;
2078 data += *ppos;
2079 len -= *ppos;
2081 if (len > *lenp)
2082 len = *lenp;
2083 if (len)
2084 if(copy_to_user(buffer, data, len))
2085 return -EFAULT;
2086 if (len < *lenp) {
2087 if(put_user('\n', ((char __user *) buffer) + len))
2088 return -EFAULT;
2089 len++;
2091 *lenp = len;
2092 *ppos += len;
2094 return 0;
2098 * proc_dostring - read a string sysctl
2099 * @table: the sysctl table
2100 * @write: %TRUE if this is a write to the sysctl file
2101 * @buffer: the user buffer
2102 * @lenp: the size of the user buffer
2103 * @ppos: file position
2105 * Reads/writes a string from/to the user buffer. If the kernel
2106 * buffer provided is not large enough to hold the string, the
2107 * string is truncated. The copied string is %NULL-terminated.
2108 * If the string is being read by the user process, it is copied
2109 * and a newline '\n' is added. It is truncated if the buffer is
2110 * not large enough.
2112 * Returns 0 on success.
2114 int proc_dostring(struct ctl_table *table, int write,
2115 void __user *buffer, size_t *lenp, loff_t *ppos)
2117 return _proc_do_string(table->data, table->maxlen, write,
2118 buffer, lenp, ppos);
2121 static size_t proc_skip_spaces(char **buf)
2123 size_t ret;
2124 char *tmp = skip_spaces(*buf);
2125 ret = tmp - *buf;
2126 *buf = tmp;
2127 return ret;
2130 static void proc_skip_char(char **buf, size_t *size, const char v)
2132 while (*size) {
2133 if (**buf != v)
2134 break;
2135 (*size)--;
2136 (*buf)++;
2140 #define TMPBUFLEN 22
2142 * proc_get_long - reads an ASCII formatted integer from a user buffer
2144 * @buf: a kernel buffer
2145 * @size: size of the kernel buffer
2146 * @val: this is where the number will be stored
2147 * @neg: set to %TRUE if number is negative
2148 * @perm_tr: a vector which contains the allowed trailers
2149 * @perm_tr_len: size of the perm_tr vector
2150 * @tr: pointer to store the trailer character
2152 * In case of success %0 is returned and @buf and @size are updated with
2153 * the amount of bytes read. If @tr is non-NULL and a trailing
2154 * character exists (size is non-zero after returning from this
2155 * function), @tr is updated with the trailing character.
2157 static int proc_get_long(char **buf, size_t *size,
2158 unsigned long *val, bool *neg,
2159 const char *perm_tr, unsigned perm_tr_len, char *tr)
2161 int len;
2162 char *p, tmp[TMPBUFLEN];
2164 if (!*size)
2165 return -EINVAL;
2167 len = *size;
2168 if (len > TMPBUFLEN - 1)
2169 len = TMPBUFLEN - 1;
2171 memcpy(tmp, *buf, len);
2173 tmp[len] = 0;
2174 p = tmp;
2175 if (*p == '-' && *size > 1) {
2176 *neg = true;
2177 p++;
2178 } else
2179 *neg = false;
2180 if (!isdigit(*p))
2181 return -EINVAL;
2183 *val = simple_strtoul(p, &p, 0);
2185 len = p - tmp;
2187 /* We don't know if the next char is whitespace thus we may accept
2188 * invalid integers (e.g. 1234...a) or two integers instead of one
2189 * (e.g. 123...1). So lets not allow such large numbers. */
2190 if (len == TMPBUFLEN - 1)
2191 return -EINVAL;
2193 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2194 return -EINVAL;
2196 if (tr && (len < *size))
2197 *tr = *p;
2199 *buf += len;
2200 *size -= len;
2202 return 0;
2206 * proc_put_long - converts an integer to a decimal ASCII formatted string
2208 * @buf: the user buffer
2209 * @size: the size of the user buffer
2210 * @val: the integer to be converted
2211 * @neg: sign of the number, %TRUE for negative
2213 * In case of success %0 is returned and @buf and @size are updated with
2214 * the amount of bytes written.
2216 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2217 bool neg)
2219 int len;
2220 char tmp[TMPBUFLEN], *p = tmp;
2222 sprintf(p, "%s%lu", neg ? "-" : "", val);
2223 len = strlen(tmp);
2224 if (len > *size)
2225 len = *size;
2226 if (copy_to_user(*buf, tmp, len))
2227 return -EFAULT;
2228 *size -= len;
2229 *buf += len;
2230 return 0;
2232 #undef TMPBUFLEN
2234 static int proc_put_char(void __user **buf, size_t *size, char c)
2236 if (*size) {
2237 char __user **buffer = (char __user **)buf;
2238 if (put_user(c, *buffer))
2239 return -EFAULT;
2240 (*size)--, (*buffer)++;
2241 *buf = *buffer;
2243 return 0;
2246 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2247 int *valp,
2248 int write, void *data)
2250 if (write) {
2251 *valp = *negp ? -*lvalp : *lvalp;
2252 } else {
2253 int val = *valp;
2254 if (val < 0) {
2255 *negp = true;
2256 *lvalp = (unsigned long)-val;
2257 } else {
2258 *negp = false;
2259 *lvalp = (unsigned long)val;
2262 return 0;
2265 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2267 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2268 int write, void __user *buffer,
2269 size_t *lenp, loff_t *ppos,
2270 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2271 int write, void *data),
2272 void *data)
2274 int *i, vleft, first = 1, err = 0;
2275 unsigned long page = 0;
2276 size_t left;
2277 char *kbuf;
2279 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2280 *lenp = 0;
2281 return 0;
2284 i = (int *) tbl_data;
2285 vleft = table->maxlen / sizeof(*i);
2286 left = *lenp;
2288 if (!conv)
2289 conv = do_proc_dointvec_conv;
2291 if (write) {
2292 if (left > PAGE_SIZE - 1)
2293 left = PAGE_SIZE - 1;
2294 page = __get_free_page(GFP_TEMPORARY);
2295 kbuf = (char *) page;
2296 if (!kbuf)
2297 return -ENOMEM;
2298 if (copy_from_user(kbuf, buffer, left)) {
2299 err = -EFAULT;
2300 goto free;
2302 kbuf[left] = 0;
2305 for (; left && vleft--; i++, first=0) {
2306 unsigned long lval;
2307 bool neg;
2309 if (write) {
2310 left -= proc_skip_spaces(&kbuf);
2312 if (!left)
2313 break;
2314 err = proc_get_long(&kbuf, &left, &lval, &neg,
2315 proc_wspace_sep,
2316 sizeof(proc_wspace_sep), NULL);
2317 if (err)
2318 break;
2319 if (conv(&neg, &lval, i, 1, data)) {
2320 err = -EINVAL;
2321 break;
2323 } else {
2324 if (conv(&neg, &lval, i, 0, data)) {
2325 err = -EINVAL;
2326 break;
2328 if (!first)
2329 err = proc_put_char(&buffer, &left, '\t');
2330 if (err)
2331 break;
2332 err = proc_put_long(&buffer, &left, lval, neg);
2333 if (err)
2334 break;
2338 if (!write && !first && left && !err)
2339 err = proc_put_char(&buffer, &left, '\n');
2340 if (write && !err && left)
2341 left -= proc_skip_spaces(&kbuf);
2342 free:
2343 if (write) {
2344 free_page(page);
2345 if (first)
2346 return err ? : -EINVAL;
2348 *lenp -= left;
2349 *ppos += *lenp;
2350 return err;
2353 static int do_proc_dointvec(struct ctl_table *table, int write,
2354 void __user *buffer, size_t *lenp, loff_t *ppos,
2355 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2356 int write, void *data),
2357 void *data)
2359 return __do_proc_dointvec(table->data, table, write,
2360 buffer, lenp, ppos, conv, data);
2364 * proc_dointvec - read a vector of integers
2365 * @table: the sysctl table
2366 * @write: %TRUE if this is a write to the sysctl file
2367 * @buffer: the user buffer
2368 * @lenp: the size of the user buffer
2369 * @ppos: file position
2371 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2372 * values from/to the user buffer, treated as an ASCII string.
2374 * Returns 0 on success.
2376 int proc_dointvec(struct ctl_table *table, int write,
2377 void __user *buffer, size_t *lenp, loff_t *ppos)
2379 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2380 NULL,NULL);
2384 * Taint values can only be increased
2385 * This means we can safely use a temporary.
2387 static int proc_taint(struct ctl_table *table, int write,
2388 void __user *buffer, size_t *lenp, loff_t *ppos)
2390 struct ctl_table t;
2391 unsigned long tmptaint = get_taint();
2392 int err;
2394 if (write && !capable(CAP_SYS_ADMIN))
2395 return -EPERM;
2397 t = *table;
2398 t.data = &tmptaint;
2399 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2400 if (err < 0)
2401 return err;
2403 if (write) {
2405 * Poor man's atomic or. Not worth adding a primitive
2406 * to everyone's atomic.h for this
2408 int i;
2409 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2410 if ((tmptaint >> i) & 1)
2411 add_taint(i);
2415 return err;
2418 #ifdef CONFIG_PRINTK
2419 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2420 void __user *buffer, size_t *lenp, loff_t *ppos)
2422 if (write && !capable(CAP_SYS_ADMIN))
2423 return -EPERM;
2425 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2427 #endif
2429 struct do_proc_dointvec_minmax_conv_param {
2430 int *min;
2431 int *max;
2434 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2435 int *valp,
2436 int write, void *data)
2438 struct do_proc_dointvec_minmax_conv_param *param = data;
2439 if (write) {
2440 int val = *negp ? -*lvalp : *lvalp;
2441 if ((param->min && *param->min > val) ||
2442 (param->max && *param->max < val))
2443 return -EINVAL;
2444 *valp = val;
2445 } else {
2446 int val = *valp;
2447 if (val < 0) {
2448 *negp = true;
2449 *lvalp = (unsigned long)-val;
2450 } else {
2451 *negp = false;
2452 *lvalp = (unsigned long)val;
2455 return 0;
2459 * proc_dointvec_minmax - read a vector of integers with min/max values
2460 * @table: the sysctl table
2461 * @write: %TRUE if this is a write to the sysctl file
2462 * @buffer: the user buffer
2463 * @lenp: the size of the user buffer
2464 * @ppos: file position
2466 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2467 * values from/to the user buffer, treated as an ASCII string.
2469 * This routine will ensure the values are within the range specified by
2470 * table->extra1 (min) and table->extra2 (max).
2472 * Returns 0 on success.
2474 int proc_dointvec_minmax(struct ctl_table *table, int write,
2475 void __user *buffer, size_t *lenp, loff_t *ppos)
2477 struct do_proc_dointvec_minmax_conv_param param = {
2478 .min = (int *) table->extra1,
2479 .max = (int *) table->extra2,
2481 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2482 do_proc_dointvec_minmax_conv, &param);
2485 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2486 void __user *buffer,
2487 size_t *lenp, loff_t *ppos,
2488 unsigned long convmul,
2489 unsigned long convdiv)
2491 unsigned long *i, *min, *max;
2492 int vleft, first = 1, err = 0;
2493 unsigned long page = 0;
2494 size_t left;
2495 char *kbuf;
2497 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2498 *lenp = 0;
2499 return 0;
2502 i = (unsigned long *) data;
2503 min = (unsigned long *) table->extra1;
2504 max = (unsigned long *) table->extra2;
2505 vleft = table->maxlen / sizeof(unsigned long);
2506 left = *lenp;
2508 if (write) {
2509 if (left > PAGE_SIZE - 1)
2510 left = PAGE_SIZE - 1;
2511 page = __get_free_page(GFP_TEMPORARY);
2512 kbuf = (char *) page;
2513 if (!kbuf)
2514 return -ENOMEM;
2515 if (copy_from_user(kbuf, buffer, left)) {
2516 err = -EFAULT;
2517 goto free;
2519 kbuf[left] = 0;
2522 for (; left && vleft--; i++, first = 0) {
2523 unsigned long val;
2525 if (write) {
2526 bool neg;
2528 left -= proc_skip_spaces(&kbuf);
2530 err = proc_get_long(&kbuf, &left, &val, &neg,
2531 proc_wspace_sep,
2532 sizeof(proc_wspace_sep), NULL);
2533 if (err)
2534 break;
2535 if (neg)
2536 continue;
2537 if ((min && val < *min) || (max && val > *max))
2538 continue;
2539 *i = val;
2540 } else {
2541 val = convdiv * (*i) / convmul;
2542 if (!first)
2543 err = proc_put_char(&buffer, &left, '\t');
2544 err = proc_put_long(&buffer, &left, val, false);
2545 if (err)
2546 break;
2550 if (!write && !first && left && !err)
2551 err = proc_put_char(&buffer, &left, '\n');
2552 if (write && !err)
2553 left -= proc_skip_spaces(&kbuf);
2554 free:
2555 if (write) {
2556 free_page(page);
2557 if (first)
2558 return err ? : -EINVAL;
2560 *lenp -= left;
2561 *ppos += *lenp;
2562 return err;
2565 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2566 void __user *buffer,
2567 size_t *lenp, loff_t *ppos,
2568 unsigned long convmul,
2569 unsigned long convdiv)
2571 return __do_proc_doulongvec_minmax(table->data, table, write,
2572 buffer, lenp, ppos, convmul, convdiv);
2576 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2577 * @table: the sysctl table
2578 * @write: %TRUE if this is a write to the sysctl file
2579 * @buffer: the user buffer
2580 * @lenp: the size of the user buffer
2581 * @ppos: file position
2583 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2584 * values from/to the user buffer, treated as an ASCII string.
2586 * This routine will ensure the values are within the range specified by
2587 * table->extra1 (min) and table->extra2 (max).
2589 * Returns 0 on success.
2591 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2592 void __user *buffer, size_t *lenp, loff_t *ppos)
2594 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2598 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2599 * @table: the sysctl table
2600 * @write: %TRUE if this is a write to the sysctl file
2601 * @buffer: the user buffer
2602 * @lenp: the size of the user buffer
2603 * @ppos: file position
2605 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2606 * values from/to the user buffer, treated as an ASCII string. The values
2607 * are treated as milliseconds, and converted to jiffies when they are stored.
2609 * This routine will ensure the values are within the range specified by
2610 * table->extra1 (min) and table->extra2 (max).
2612 * Returns 0 on success.
2614 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2615 void __user *buffer,
2616 size_t *lenp, loff_t *ppos)
2618 return do_proc_doulongvec_minmax(table, write, buffer,
2619 lenp, ppos, HZ, 1000l);
2623 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2624 int *valp,
2625 int write, void *data)
2627 if (write) {
2628 if (*lvalp > LONG_MAX / HZ)
2629 return 1;
2630 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2631 } else {
2632 int val = *valp;
2633 unsigned long lval;
2634 if (val < 0) {
2635 *negp = true;
2636 lval = (unsigned long)-val;
2637 } else {
2638 *negp = false;
2639 lval = (unsigned long)val;
2641 *lvalp = lval / HZ;
2643 return 0;
2646 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2647 int *valp,
2648 int write, void *data)
2650 if (write) {
2651 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2652 return 1;
2653 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2654 } else {
2655 int val = *valp;
2656 unsigned long lval;
2657 if (val < 0) {
2658 *negp = true;
2659 lval = (unsigned long)-val;
2660 } else {
2661 *negp = false;
2662 lval = (unsigned long)val;
2664 *lvalp = jiffies_to_clock_t(lval);
2666 return 0;
2669 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2670 int *valp,
2671 int write, void *data)
2673 if (write) {
2674 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2675 } else {
2676 int val = *valp;
2677 unsigned long lval;
2678 if (val < 0) {
2679 *negp = true;
2680 lval = (unsigned long)-val;
2681 } else {
2682 *negp = false;
2683 lval = (unsigned long)val;
2685 *lvalp = jiffies_to_msecs(lval);
2687 return 0;
2691 * proc_dointvec_jiffies - read a vector of integers as seconds
2692 * @table: the sysctl table
2693 * @write: %TRUE if this is a write to the sysctl file
2694 * @buffer: the user buffer
2695 * @lenp: the size of the user buffer
2696 * @ppos: file position
2698 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2699 * values from/to the user buffer, treated as an ASCII string.
2700 * The values read are assumed to be in seconds, and are converted into
2701 * jiffies.
2703 * Returns 0 on success.
2705 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2706 void __user *buffer, size_t *lenp, loff_t *ppos)
2708 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2709 do_proc_dointvec_jiffies_conv,NULL);
2713 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2714 * @table: the sysctl table
2715 * @write: %TRUE if this is a write to the sysctl file
2716 * @buffer: the user buffer
2717 * @lenp: the size of the user buffer
2718 * @ppos: pointer to the file position
2720 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2721 * values from/to the user buffer, treated as an ASCII string.
2722 * The values read are assumed to be in 1/USER_HZ seconds, and
2723 * are converted into jiffies.
2725 * Returns 0 on success.
2727 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2728 void __user *buffer, size_t *lenp, loff_t *ppos)
2730 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2731 do_proc_dointvec_userhz_jiffies_conv,NULL);
2735 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2736 * @table: the sysctl table
2737 * @write: %TRUE if this is a write to the sysctl file
2738 * @buffer: the user buffer
2739 * @lenp: the size of the user buffer
2740 * @ppos: file position
2741 * @ppos: the current position in the file
2743 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2744 * values from/to the user buffer, treated as an ASCII string.
2745 * The values read are assumed to be in 1/1000 seconds, and
2746 * are converted into jiffies.
2748 * Returns 0 on success.
2750 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2751 void __user *buffer, size_t *lenp, loff_t *ppos)
2753 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2754 do_proc_dointvec_ms_jiffies_conv, NULL);
2757 static int proc_do_cad_pid(struct ctl_table *table, int write,
2758 void __user *buffer, size_t *lenp, loff_t *ppos)
2760 struct pid *new_pid;
2761 pid_t tmp;
2762 int r;
2764 tmp = pid_vnr(cad_pid);
2766 r = __do_proc_dointvec(&tmp, table, write, buffer,
2767 lenp, ppos, NULL, NULL);
2768 if (r || !write)
2769 return r;
2771 new_pid = find_get_pid(tmp);
2772 if (!new_pid)
2773 return -ESRCH;
2775 put_pid(xchg(&cad_pid, new_pid));
2776 return 0;
2780 * proc_do_large_bitmap - read/write from/to a large bitmap
2781 * @table: the sysctl table
2782 * @write: %TRUE if this is a write to the sysctl file
2783 * @buffer: the user buffer
2784 * @lenp: the size of the user buffer
2785 * @ppos: file position
2787 * The bitmap is stored at table->data and the bitmap length (in bits)
2788 * in table->maxlen.
2790 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2791 * large bitmaps may be represented in a compact manner. Writing into
2792 * the file will clear the bitmap then update it with the given input.
2794 * Returns 0 on success.
2796 int proc_do_large_bitmap(struct ctl_table *table, int write,
2797 void __user *buffer, size_t *lenp, loff_t *ppos)
2799 int err = 0;
2800 bool first = 1;
2801 size_t left = *lenp;
2802 unsigned long bitmap_len = table->maxlen;
2803 unsigned long *bitmap = (unsigned long *) table->data;
2804 unsigned long *tmp_bitmap = NULL;
2805 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2807 if (!bitmap_len || !left || (*ppos && !write)) {
2808 *lenp = 0;
2809 return 0;
2812 if (write) {
2813 unsigned long page = 0;
2814 char *kbuf;
2816 if (left > PAGE_SIZE - 1)
2817 left = PAGE_SIZE - 1;
2819 page = __get_free_page(GFP_TEMPORARY);
2820 kbuf = (char *) page;
2821 if (!kbuf)
2822 return -ENOMEM;
2823 if (copy_from_user(kbuf, buffer, left)) {
2824 free_page(page);
2825 return -EFAULT;
2827 kbuf[left] = 0;
2829 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2830 GFP_KERNEL);
2831 if (!tmp_bitmap) {
2832 free_page(page);
2833 return -ENOMEM;
2835 proc_skip_char(&kbuf, &left, '\n');
2836 while (!err && left) {
2837 unsigned long val_a, val_b;
2838 bool neg;
2840 err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2841 sizeof(tr_a), &c);
2842 if (err)
2843 break;
2844 if (val_a >= bitmap_len || neg) {
2845 err = -EINVAL;
2846 break;
2849 val_b = val_a;
2850 if (left) {
2851 kbuf++;
2852 left--;
2855 if (c == '-') {
2856 err = proc_get_long(&kbuf, &left, &val_b,
2857 &neg, tr_b, sizeof(tr_b),
2858 &c);
2859 if (err)
2860 break;
2861 if (val_b >= bitmap_len || neg ||
2862 val_a > val_b) {
2863 err = -EINVAL;
2864 break;
2866 if (left) {
2867 kbuf++;
2868 left--;
2872 while (val_a <= val_b)
2873 set_bit(val_a++, tmp_bitmap);
2875 first = 0;
2876 proc_skip_char(&kbuf, &left, '\n');
2878 free_page(page);
2879 } else {
2880 unsigned long bit_a, bit_b = 0;
2882 while (left) {
2883 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2884 if (bit_a >= bitmap_len)
2885 break;
2886 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2887 bit_a + 1) - 1;
2889 if (!first) {
2890 err = proc_put_char(&buffer, &left, ',');
2891 if (err)
2892 break;
2894 err = proc_put_long(&buffer, &left, bit_a, false);
2895 if (err)
2896 break;
2897 if (bit_a != bit_b) {
2898 err = proc_put_char(&buffer, &left, '-');
2899 if (err)
2900 break;
2901 err = proc_put_long(&buffer, &left, bit_b, false);
2902 if (err)
2903 break;
2906 first = 0; bit_b++;
2908 if (!err)
2909 err = proc_put_char(&buffer, &left, '\n');
2912 if (!err) {
2913 if (write) {
2914 if (*ppos)
2915 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2916 else
2917 memcpy(bitmap, tmp_bitmap,
2918 BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2920 kfree(tmp_bitmap);
2921 *lenp -= left;
2922 *ppos += *lenp;
2923 return 0;
2924 } else {
2925 kfree(tmp_bitmap);
2926 return err;
2930 #else /* CONFIG_PROC_SYSCTL */
2932 int proc_dostring(struct ctl_table *table, int write,
2933 void __user *buffer, size_t *lenp, loff_t *ppos)
2935 return -ENOSYS;
2938 int proc_dointvec(struct ctl_table *table, int write,
2939 void __user *buffer, size_t *lenp, loff_t *ppos)
2941 return -ENOSYS;
2944 int proc_dointvec_minmax(struct ctl_table *table, int write,
2945 void __user *buffer, size_t *lenp, loff_t *ppos)
2947 return -ENOSYS;
2950 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2951 void __user *buffer, size_t *lenp, loff_t *ppos)
2953 return -ENOSYS;
2956 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2957 void __user *buffer, size_t *lenp, loff_t *ppos)
2959 return -ENOSYS;
2962 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2963 void __user *buffer, size_t *lenp, loff_t *ppos)
2965 return -ENOSYS;
2968 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2969 void __user *buffer, size_t *lenp, loff_t *ppos)
2971 return -ENOSYS;
2974 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2975 void __user *buffer,
2976 size_t *lenp, loff_t *ppos)
2978 return -ENOSYS;
2982 #endif /* CONFIG_PROC_SYSCTL */
2985 * No sense putting this after each symbol definition, twice,
2986 * exception granted :-)
2988 EXPORT_SYMBOL(proc_dointvec);
2989 EXPORT_SYMBOL(proc_dointvec_jiffies);
2990 EXPORT_SYMBOL(proc_dointvec_minmax);
2991 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2992 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2993 EXPORT_SYMBOL(proc_dostring);
2994 EXPORT_SYMBOL(proc_doulongvec_minmax);
2995 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2996 EXPORT_SYMBOL(register_sysctl_table);
2997 EXPORT_SYMBOL(register_sysctl_paths);
2998 EXPORT_SYMBOL(unregister_sysctl_table);