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
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
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>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/signal.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/ctype.h>
30 #include <linux/kmemcheck.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/ratelimit.h>
40 #include <linux/hugetlb.h>
41 #include <linux/initrd.h>
42 #include <linux/key.h>
43 #include <linux/times.h>
44 #include <linux/limits.h>
45 #include <linux/dcache.h>
46 #include <linux/syscalls.h>
47 #include <linux/vmstat.h>
48 #include <linux/nfs_fs.h>
49 #include <linux/acpi.h>
50 #include <linux/reboot.h>
51 #include <linux/ftrace.h>
52 #include <linux/slow-work.h>
53 #include <linux/perf_event.h>
54 #include <linux/kprobes.h>
56 #include <asm/uaccess.h>
57 #include <asm/processor.h>
61 #include <asm/stacktrace.h>
66 #if defined(CONFIG_SYSCTL)
68 /* External variables not in a header file. */
69 extern int sysctl_overcommit_memory;
70 extern int sysctl_overcommit_ratio;
71 extern int sysctl_panic_on_oom;
72 extern int sysctl_oom_kill_allocating_task;
73 extern int sysctl_oom_dump_tasks;
74 extern int max_threads;
75 extern int core_uses_pid;
76 extern int suid_dumpable;
77 extern char core_pattern[];
78 extern unsigned int core_pipe_limit;
80 extern int min_free_kbytes;
81 extern int pid_max_min, pid_max_max;
82 extern int sysctl_drop_caches;
83 extern int percpu_pagelist_fraction;
84 extern int compat_log;
85 extern int latencytop_enabled;
86 extern int sysctl_nr_open_min, sysctl_nr_open_max;
88 extern int sysctl_nr_trim_pages;
91 extern int blk_iopoll_enabled;
94 /* Constants used for minimum and maximum */
95 #ifdef CONFIG_DETECT_SOFTLOCKUP
96 static int sixty = 60;
97 static int neg_one = -1;
101 static int __maybe_unused one = 1;
102 static int __maybe_unused two = 2;
103 static unsigned long one_ul = 1;
104 static int one_hundred = 100;
106 static int ten_thousand = 10000;
109 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
110 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
112 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
113 static int maxolduid = 65535;
114 static int minolduid;
115 static int min_percpu_pagelist_fract = 8;
117 static int ngroups_max = NGROUPS_MAX;
119 #ifdef CONFIG_MODULES
120 extern char modprobe_path[];
121 extern int modules_disabled;
123 #ifdef CONFIG_CHR_DEV_SG
124 extern int sg_big_buff;
128 #include <asm/system.h>
131 #ifdef CONFIG_SPARC64
132 extern int sysctl_tsb_ratio;
136 extern int pwrsw_enabled;
137 extern int unaligned_enabled;
141 #ifdef CONFIG_MATHEMU
142 extern int sysctl_ieee_emulation_warnings;
144 extern int sysctl_userprocess_debug;
145 extern int spin_retry;
148 #ifdef CONFIG_BSD_PROCESS_ACCT
149 extern int acct_parm[];
153 extern int no_unaligned_warning;
154 extern int unaligned_dump_stack;
157 extern struct ratelimit_state printk_ratelimit_state;
159 #ifdef CONFIG_RT_MUTEXES
160 extern int max_lock_depth;
163 #ifdef CONFIG_PROC_SYSCTL
164 static int proc_do_cad_pid(struct ctl_table *table, int write,
165 void __user *buffer, size_t *lenp, loff_t *ppos);
166 static int proc_taint(struct ctl_table *table, int write,
167 void __user *buffer, size_t *lenp, loff_t *ppos);
170 static struct ctl_table root_table[];
171 static struct ctl_table_root sysctl_table_root;
172 static struct ctl_table_header root_table_header = {
174 .ctl_table = root_table,
175 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
176 .root = &sysctl_table_root,
177 .set = &sysctl_table_root.default_set,
179 static struct ctl_table_root sysctl_table_root = {
180 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
181 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
184 static struct ctl_table kern_table[];
185 static struct ctl_table vm_table[];
186 static struct ctl_table fs_table[];
187 static struct ctl_table debug_table[];
188 static struct ctl_table dev_table[];
189 extern struct ctl_table random_table[];
190 #ifdef CONFIG_INOTIFY_USER
191 extern struct ctl_table inotify_table[];
194 extern struct ctl_table epoll_table[];
197 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
198 int sysctl_legacy_va_layout;
201 extern int prove_locking;
202 extern int lock_stat;
204 /* The default sysctl tables: */
206 static struct ctl_table root_table[] = {
208 .procname = "kernel",
225 .child = debug_table,
233 * NOTE: do not add new entries to this table unless you have read
234 * Documentation/sysctl/ctl_unnumbered.txt
239 #ifdef CONFIG_SCHED_DEBUG
240 static int min_sched_granularity_ns = 100000; /* 100 usecs */
241 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
242 static int min_wakeup_granularity_ns; /* 0 usecs */
243 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
244 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
245 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
246 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
247 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
250 static struct ctl_table kern_table[] = {
252 .procname = "sched_child_runs_first",
253 .data = &sysctl_sched_child_runs_first,
254 .maxlen = sizeof(unsigned int),
256 .proc_handler = proc_dointvec,
258 #ifdef CONFIG_SCHED_DEBUG
260 .procname = "sched_min_granularity_ns",
261 .data = &sysctl_sched_min_granularity,
262 .maxlen = sizeof(unsigned int),
264 .proc_handler = sched_proc_update_handler,
265 .extra1 = &min_sched_granularity_ns,
266 .extra2 = &max_sched_granularity_ns,
269 .procname = "sched_latency_ns",
270 .data = &sysctl_sched_latency,
271 .maxlen = sizeof(unsigned int),
273 .proc_handler = sched_proc_update_handler,
274 .extra1 = &min_sched_granularity_ns,
275 .extra2 = &max_sched_granularity_ns,
278 .procname = "sched_wakeup_granularity_ns",
279 .data = &sysctl_sched_wakeup_granularity,
280 .maxlen = sizeof(unsigned int),
282 .proc_handler = sched_proc_update_handler,
283 .extra1 = &min_wakeup_granularity_ns,
284 .extra2 = &max_wakeup_granularity_ns,
287 .procname = "sched_shares_ratelimit",
288 .data = &sysctl_sched_shares_ratelimit,
289 .maxlen = sizeof(unsigned int),
291 .proc_handler = sched_proc_update_handler,
292 .extra1 = &min_sched_shares_ratelimit,
293 .extra2 = &max_sched_shares_ratelimit,
296 .procname = "sched_tunable_scaling",
297 .data = &sysctl_sched_tunable_scaling,
298 .maxlen = sizeof(enum sched_tunable_scaling),
300 .proc_handler = sched_proc_update_handler,
301 .extra1 = &min_sched_tunable_scaling,
302 .extra2 = &max_sched_tunable_scaling,
305 .procname = "sched_shares_thresh",
306 .data = &sysctl_sched_shares_thresh,
307 .maxlen = sizeof(unsigned int),
309 .proc_handler = proc_dointvec_minmax,
313 .procname = "sched_migration_cost",
314 .data = &sysctl_sched_migration_cost,
315 .maxlen = sizeof(unsigned int),
317 .proc_handler = proc_dointvec,
320 .procname = "sched_nr_migrate",
321 .data = &sysctl_sched_nr_migrate,
322 .maxlen = sizeof(unsigned int),
324 .proc_handler = proc_dointvec,
327 .procname = "sched_time_avg",
328 .data = &sysctl_sched_time_avg,
329 .maxlen = sizeof(unsigned int),
331 .proc_handler = proc_dointvec,
334 .procname = "timer_migration",
335 .data = &sysctl_timer_migration,
336 .maxlen = sizeof(unsigned int),
338 .proc_handler = proc_dointvec_minmax,
344 .procname = "sched_rt_period_us",
345 .data = &sysctl_sched_rt_period,
346 .maxlen = sizeof(unsigned int),
348 .proc_handler = sched_rt_handler,
351 .procname = "sched_rt_runtime_us",
352 .data = &sysctl_sched_rt_runtime,
353 .maxlen = sizeof(int),
355 .proc_handler = sched_rt_handler,
358 .procname = "sched_compat_yield",
359 .data = &sysctl_sched_compat_yield,
360 .maxlen = sizeof(unsigned int),
362 .proc_handler = proc_dointvec,
364 #ifdef CONFIG_PROVE_LOCKING
366 .procname = "prove_locking",
367 .data = &prove_locking,
368 .maxlen = sizeof(int),
370 .proc_handler = proc_dointvec,
373 #ifdef CONFIG_LOCK_STAT
375 .procname = "lock_stat",
377 .maxlen = sizeof(int),
379 .proc_handler = proc_dointvec,
384 .data = &panic_timeout,
385 .maxlen = sizeof(int),
387 .proc_handler = proc_dointvec,
390 .procname = "core_uses_pid",
391 .data = &core_uses_pid,
392 .maxlen = sizeof(int),
394 .proc_handler = proc_dointvec,
397 .procname = "core_pattern",
398 .data = core_pattern,
399 .maxlen = CORENAME_MAX_SIZE,
401 .proc_handler = proc_dostring,
404 .procname = "core_pipe_limit",
405 .data = &core_pipe_limit,
406 .maxlen = sizeof(unsigned int),
408 .proc_handler = proc_dointvec,
410 #ifdef CONFIG_PROC_SYSCTL
412 .procname = "tainted",
413 .maxlen = sizeof(long),
415 .proc_handler = proc_taint,
418 #ifdef CONFIG_LATENCYTOP
420 .procname = "latencytop",
421 .data = &latencytop_enabled,
422 .maxlen = sizeof(int),
424 .proc_handler = proc_dointvec,
427 #ifdef CONFIG_BLK_DEV_INITRD
429 .procname = "real-root-dev",
430 .data = &real_root_dev,
431 .maxlen = sizeof(int),
433 .proc_handler = proc_dointvec,
437 .procname = "print-fatal-signals",
438 .data = &print_fatal_signals,
439 .maxlen = sizeof(int),
441 .proc_handler = proc_dointvec,
445 .procname = "reboot-cmd",
446 .data = reboot_command,
449 .proc_handler = proc_dostring,
452 .procname = "stop-a",
453 .data = &stop_a_enabled,
454 .maxlen = sizeof (int),
456 .proc_handler = proc_dointvec,
459 .procname = "scons-poweroff",
460 .data = &scons_pwroff,
461 .maxlen = sizeof (int),
463 .proc_handler = proc_dointvec,
466 #ifdef CONFIG_SPARC64
468 .procname = "tsb-ratio",
469 .data = &sysctl_tsb_ratio,
470 .maxlen = sizeof (int),
472 .proc_handler = proc_dointvec,
477 .procname = "soft-power",
478 .data = &pwrsw_enabled,
479 .maxlen = sizeof (int),
481 .proc_handler = proc_dointvec,
484 .procname = "unaligned-trap",
485 .data = &unaligned_enabled,
486 .maxlen = sizeof (int),
488 .proc_handler = proc_dointvec,
492 .procname = "ctrl-alt-del",
494 .maxlen = sizeof(int),
496 .proc_handler = proc_dointvec,
498 #ifdef CONFIG_FUNCTION_TRACER
500 .procname = "ftrace_enabled",
501 .data = &ftrace_enabled,
502 .maxlen = sizeof(int),
504 .proc_handler = ftrace_enable_sysctl,
507 #ifdef CONFIG_STACK_TRACER
509 .procname = "stack_tracer_enabled",
510 .data = &stack_tracer_enabled,
511 .maxlen = sizeof(int),
513 .proc_handler = stack_trace_sysctl,
516 #ifdef CONFIG_TRACING
518 .procname = "ftrace_dump_on_oops",
519 .data = &ftrace_dump_on_oops,
520 .maxlen = sizeof(int),
522 .proc_handler = proc_dointvec,
525 #ifdef CONFIG_MODULES
527 .procname = "modprobe",
528 .data = &modprobe_path,
529 .maxlen = KMOD_PATH_LEN,
531 .proc_handler = proc_dostring,
534 .procname = "modules_disabled",
535 .data = &modules_disabled,
536 .maxlen = sizeof(int),
538 /* only handle a transition from default "0" to "1" */
539 .proc_handler = proc_dointvec_minmax,
544 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
546 .procname = "hotplug",
547 .data = &uevent_helper,
548 .maxlen = UEVENT_HELPER_PATH_LEN,
550 .proc_handler = proc_dostring,
553 #ifdef CONFIG_CHR_DEV_SG
555 .procname = "sg-big-buff",
556 .data = &sg_big_buff,
557 .maxlen = sizeof (int),
559 .proc_handler = proc_dointvec,
562 #ifdef CONFIG_BSD_PROCESS_ACCT
566 .maxlen = 3*sizeof(int),
568 .proc_handler = proc_dointvec,
571 #ifdef CONFIG_MAGIC_SYSRQ
574 .data = &__sysrq_enabled,
575 .maxlen = sizeof (int),
577 .proc_handler = proc_dointvec,
580 #ifdef CONFIG_PROC_SYSCTL
582 .procname = "cad_pid",
584 .maxlen = sizeof (int),
586 .proc_handler = proc_do_cad_pid,
590 .procname = "threads-max",
591 .data = &max_threads,
592 .maxlen = sizeof(int),
594 .proc_handler = proc_dointvec,
597 .procname = "random",
599 .child = random_table,
602 .procname = "overflowuid",
603 .data = &overflowuid,
604 .maxlen = sizeof(int),
606 .proc_handler = proc_dointvec_minmax,
607 .extra1 = &minolduid,
608 .extra2 = &maxolduid,
611 .procname = "overflowgid",
612 .data = &overflowgid,
613 .maxlen = sizeof(int),
615 .proc_handler = proc_dointvec_minmax,
616 .extra1 = &minolduid,
617 .extra2 = &maxolduid,
620 #ifdef CONFIG_MATHEMU
622 .procname = "ieee_emulation_warnings",
623 .data = &sysctl_ieee_emulation_warnings,
624 .maxlen = sizeof(int),
626 .proc_handler = proc_dointvec,
630 .procname = "userprocess_debug",
631 .data = &sysctl_userprocess_debug,
632 .maxlen = sizeof(int),
634 .proc_handler = proc_dointvec,
638 .procname = "pid_max",
640 .maxlen = sizeof (int),
642 .proc_handler = proc_dointvec_minmax,
643 .extra1 = &pid_max_min,
644 .extra2 = &pid_max_max,
647 .procname = "panic_on_oops",
648 .data = &panic_on_oops,
649 .maxlen = sizeof(int),
651 .proc_handler = proc_dointvec,
653 #if defined CONFIG_PRINTK
655 .procname = "printk",
656 .data = &console_loglevel,
657 .maxlen = 4*sizeof(int),
659 .proc_handler = proc_dointvec,
662 .procname = "printk_ratelimit",
663 .data = &printk_ratelimit_state.interval,
664 .maxlen = sizeof(int),
666 .proc_handler = proc_dointvec_jiffies,
669 .procname = "printk_ratelimit_burst",
670 .data = &printk_ratelimit_state.burst,
671 .maxlen = sizeof(int),
673 .proc_handler = proc_dointvec,
676 .procname = "printk_delay",
677 .data = &printk_delay_msec,
678 .maxlen = sizeof(int),
680 .proc_handler = proc_dointvec_minmax,
682 .extra2 = &ten_thousand,
686 .procname = "ngroups_max",
687 .data = &ngroups_max,
688 .maxlen = sizeof (int),
690 .proc_handler = proc_dointvec,
692 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
694 .procname = "unknown_nmi_panic",
695 .data = &unknown_nmi_panic,
696 .maxlen = sizeof (int),
698 .proc_handler = proc_dointvec,
701 .procname = "nmi_watchdog",
702 .data = &nmi_watchdog_enabled,
703 .maxlen = sizeof (int),
705 .proc_handler = proc_nmi_enabled,
708 #if defined(CONFIG_X86)
710 .procname = "panic_on_unrecovered_nmi",
711 .data = &panic_on_unrecovered_nmi,
712 .maxlen = sizeof(int),
714 .proc_handler = proc_dointvec,
717 .procname = "panic_on_io_nmi",
718 .data = &panic_on_io_nmi,
719 .maxlen = sizeof(int),
721 .proc_handler = proc_dointvec,
724 .procname = "bootloader_type",
725 .data = &bootloader_type,
726 .maxlen = sizeof (int),
728 .proc_handler = proc_dointvec,
731 .procname = "bootloader_version",
732 .data = &bootloader_version,
733 .maxlen = sizeof (int),
735 .proc_handler = proc_dointvec,
738 .procname = "kstack_depth_to_print",
739 .data = &kstack_depth_to_print,
740 .maxlen = sizeof(int),
742 .proc_handler = proc_dointvec,
745 .procname = "io_delay_type",
746 .data = &io_delay_type,
747 .maxlen = sizeof(int),
749 .proc_handler = proc_dointvec,
752 #if defined(CONFIG_MMU)
754 .procname = "randomize_va_space",
755 .data = &randomize_va_space,
756 .maxlen = sizeof(int),
758 .proc_handler = proc_dointvec,
761 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
763 .procname = "spin_retry",
765 .maxlen = sizeof (int),
767 .proc_handler = proc_dointvec,
770 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
772 .procname = "acpi_video_flags",
773 .data = &acpi_realmode_flags,
774 .maxlen = sizeof (unsigned long),
776 .proc_handler = proc_doulongvec_minmax,
781 .procname = "ignore-unaligned-usertrap",
782 .data = &no_unaligned_warning,
783 .maxlen = sizeof (int),
785 .proc_handler = proc_dointvec,
788 .procname = "unaligned-dump-stack",
789 .data = &unaligned_dump_stack,
790 .maxlen = sizeof (int),
792 .proc_handler = proc_dointvec,
795 #ifdef CONFIG_DETECT_SOFTLOCKUP
797 .procname = "softlockup_panic",
798 .data = &softlockup_panic,
799 .maxlen = sizeof(int),
801 .proc_handler = proc_dointvec_minmax,
806 .procname = "softlockup_thresh",
807 .data = &softlockup_thresh,
808 .maxlen = sizeof(int),
810 .proc_handler = proc_dosoftlockup_thresh,
815 #ifdef CONFIG_DETECT_HUNG_TASK
817 .procname = "hung_task_panic",
818 .data = &sysctl_hung_task_panic,
819 .maxlen = sizeof(int),
821 .proc_handler = proc_dointvec_minmax,
826 .procname = "hung_task_check_count",
827 .data = &sysctl_hung_task_check_count,
828 .maxlen = sizeof(unsigned long),
830 .proc_handler = proc_doulongvec_minmax,
833 .procname = "hung_task_timeout_secs",
834 .data = &sysctl_hung_task_timeout_secs,
835 .maxlen = sizeof(unsigned long),
837 .proc_handler = proc_dohung_task_timeout_secs,
840 .procname = "hung_task_warnings",
841 .data = &sysctl_hung_task_warnings,
842 .maxlen = sizeof(unsigned long),
844 .proc_handler = proc_doulongvec_minmax,
849 .procname = "compat-log",
851 .maxlen = sizeof (int),
853 .proc_handler = proc_dointvec,
856 #ifdef CONFIG_RT_MUTEXES
858 .procname = "max_lock_depth",
859 .data = &max_lock_depth,
860 .maxlen = sizeof(int),
862 .proc_handler = proc_dointvec,
866 .procname = "poweroff_cmd",
867 .data = &poweroff_cmd,
868 .maxlen = POWEROFF_CMD_PATH_LEN,
870 .proc_handler = proc_dostring,
876 .child = key_sysctls,
879 #ifdef CONFIG_RCU_TORTURE_TEST
881 .procname = "rcutorture_runnable",
882 .data = &rcutorture_runnable,
883 .maxlen = sizeof(int),
885 .proc_handler = proc_dointvec,
888 #ifdef CONFIG_SLOW_WORK
890 .procname = "slow-work",
892 .child = slow_work_sysctls,
895 #ifdef CONFIG_PERF_EVENTS
897 .procname = "perf_event_paranoid",
898 .data = &sysctl_perf_event_paranoid,
899 .maxlen = sizeof(sysctl_perf_event_paranoid),
901 .proc_handler = proc_dointvec,
904 .procname = "perf_event_mlock_kb",
905 .data = &sysctl_perf_event_mlock,
906 .maxlen = sizeof(sysctl_perf_event_mlock),
908 .proc_handler = proc_dointvec,
911 .procname = "perf_event_max_sample_rate",
912 .data = &sysctl_perf_event_sample_rate,
913 .maxlen = sizeof(sysctl_perf_event_sample_rate),
915 .proc_handler = proc_dointvec,
918 #ifdef CONFIG_KMEMCHECK
920 .procname = "kmemcheck",
921 .data = &kmemcheck_enabled,
922 .maxlen = sizeof(int),
924 .proc_handler = proc_dointvec,
929 .procname = "blk_iopoll",
930 .data = &blk_iopoll_enabled,
931 .maxlen = sizeof(int),
933 .proc_handler = proc_dointvec,
937 * NOTE: do not add new entries to this table unless you have read
938 * Documentation/sysctl/ctl_unnumbered.txt
943 static struct ctl_table vm_table[] = {
945 .procname = "overcommit_memory",
946 .data = &sysctl_overcommit_memory,
947 .maxlen = sizeof(sysctl_overcommit_memory),
949 .proc_handler = proc_dointvec,
952 .procname = "panic_on_oom",
953 .data = &sysctl_panic_on_oom,
954 .maxlen = sizeof(sysctl_panic_on_oom),
956 .proc_handler = proc_dointvec,
959 .procname = "oom_kill_allocating_task",
960 .data = &sysctl_oom_kill_allocating_task,
961 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
963 .proc_handler = proc_dointvec,
966 .procname = "oom_dump_tasks",
967 .data = &sysctl_oom_dump_tasks,
968 .maxlen = sizeof(sysctl_oom_dump_tasks),
970 .proc_handler = proc_dointvec,
973 .procname = "overcommit_ratio",
974 .data = &sysctl_overcommit_ratio,
975 .maxlen = sizeof(sysctl_overcommit_ratio),
977 .proc_handler = proc_dointvec,
980 .procname = "page-cluster",
981 .data = &page_cluster,
982 .maxlen = sizeof(int),
984 .proc_handler = proc_dointvec,
987 .procname = "dirty_background_ratio",
988 .data = &dirty_background_ratio,
989 .maxlen = sizeof(dirty_background_ratio),
991 .proc_handler = dirty_background_ratio_handler,
993 .extra2 = &one_hundred,
996 .procname = "dirty_background_bytes",
997 .data = &dirty_background_bytes,
998 .maxlen = sizeof(dirty_background_bytes),
1000 .proc_handler = dirty_background_bytes_handler,
1004 .procname = "dirty_ratio",
1005 .data = &vm_dirty_ratio,
1006 .maxlen = sizeof(vm_dirty_ratio),
1008 .proc_handler = dirty_ratio_handler,
1010 .extra2 = &one_hundred,
1013 .procname = "dirty_bytes",
1014 .data = &vm_dirty_bytes,
1015 .maxlen = sizeof(vm_dirty_bytes),
1017 .proc_handler = dirty_bytes_handler,
1018 .extra1 = &dirty_bytes_min,
1021 .procname = "dirty_writeback_centisecs",
1022 .data = &dirty_writeback_interval,
1023 .maxlen = sizeof(dirty_writeback_interval),
1025 .proc_handler = dirty_writeback_centisecs_handler,
1028 .procname = "dirty_expire_centisecs",
1029 .data = &dirty_expire_interval,
1030 .maxlen = sizeof(dirty_expire_interval),
1032 .proc_handler = proc_dointvec,
1035 .procname = "nr_pdflush_threads",
1036 .data = &nr_pdflush_threads,
1037 .maxlen = sizeof nr_pdflush_threads,
1038 .mode = 0444 /* read-only*/,
1039 .proc_handler = proc_dointvec,
1042 .procname = "swappiness",
1043 .data = &vm_swappiness,
1044 .maxlen = sizeof(vm_swappiness),
1046 .proc_handler = proc_dointvec_minmax,
1048 .extra2 = &one_hundred,
1050 #ifdef CONFIG_HUGETLB_PAGE
1052 .procname = "nr_hugepages",
1054 .maxlen = sizeof(unsigned long),
1056 .proc_handler = hugetlb_sysctl_handler,
1057 .extra1 = (void *)&hugetlb_zero,
1058 .extra2 = (void *)&hugetlb_infinity,
1062 .procname = "nr_hugepages_mempolicy",
1064 .maxlen = sizeof(unsigned long),
1066 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1067 .extra1 = (void *)&hugetlb_zero,
1068 .extra2 = (void *)&hugetlb_infinity,
1072 .procname = "hugetlb_shm_group",
1073 .data = &sysctl_hugetlb_shm_group,
1074 .maxlen = sizeof(gid_t),
1076 .proc_handler = proc_dointvec,
1079 .procname = "hugepages_treat_as_movable",
1080 .data = &hugepages_treat_as_movable,
1081 .maxlen = sizeof(int),
1083 .proc_handler = hugetlb_treat_movable_handler,
1086 .procname = "nr_overcommit_hugepages",
1088 .maxlen = sizeof(unsigned long),
1090 .proc_handler = hugetlb_overcommit_handler,
1091 .extra1 = (void *)&hugetlb_zero,
1092 .extra2 = (void *)&hugetlb_infinity,
1096 .procname = "lowmem_reserve_ratio",
1097 .data = &sysctl_lowmem_reserve_ratio,
1098 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1100 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1103 .procname = "drop_caches",
1104 .data = &sysctl_drop_caches,
1105 .maxlen = sizeof(int),
1107 .proc_handler = drop_caches_sysctl_handler,
1110 .procname = "min_free_kbytes",
1111 .data = &min_free_kbytes,
1112 .maxlen = sizeof(min_free_kbytes),
1114 .proc_handler = min_free_kbytes_sysctl_handler,
1118 .procname = "percpu_pagelist_fraction",
1119 .data = &percpu_pagelist_fraction,
1120 .maxlen = sizeof(percpu_pagelist_fraction),
1122 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1123 .extra1 = &min_percpu_pagelist_fract,
1127 .procname = "max_map_count",
1128 .data = &sysctl_max_map_count,
1129 .maxlen = sizeof(sysctl_max_map_count),
1131 .proc_handler = proc_dointvec_minmax,
1136 .procname = "nr_trim_pages",
1137 .data = &sysctl_nr_trim_pages,
1138 .maxlen = sizeof(sysctl_nr_trim_pages),
1140 .proc_handler = proc_dointvec_minmax,
1145 .procname = "laptop_mode",
1146 .data = &laptop_mode,
1147 .maxlen = sizeof(laptop_mode),
1149 .proc_handler = proc_dointvec_jiffies,
1152 .procname = "block_dump",
1153 .data = &block_dump,
1154 .maxlen = sizeof(block_dump),
1156 .proc_handler = proc_dointvec,
1160 .procname = "vfs_cache_pressure",
1161 .data = &sysctl_vfs_cache_pressure,
1162 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1164 .proc_handler = proc_dointvec,
1167 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1169 .procname = "legacy_va_layout",
1170 .data = &sysctl_legacy_va_layout,
1171 .maxlen = sizeof(sysctl_legacy_va_layout),
1173 .proc_handler = proc_dointvec,
1179 .procname = "zone_reclaim_mode",
1180 .data = &zone_reclaim_mode,
1181 .maxlen = sizeof(zone_reclaim_mode),
1183 .proc_handler = proc_dointvec,
1187 .procname = "min_unmapped_ratio",
1188 .data = &sysctl_min_unmapped_ratio,
1189 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1191 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1193 .extra2 = &one_hundred,
1196 .procname = "min_slab_ratio",
1197 .data = &sysctl_min_slab_ratio,
1198 .maxlen = sizeof(sysctl_min_slab_ratio),
1200 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1202 .extra2 = &one_hundred,
1207 .procname = "stat_interval",
1208 .data = &sysctl_stat_interval,
1209 .maxlen = sizeof(sysctl_stat_interval),
1211 .proc_handler = proc_dointvec_jiffies,
1216 .procname = "mmap_min_addr",
1217 .data = &dac_mmap_min_addr,
1218 .maxlen = sizeof(unsigned long),
1220 .proc_handler = mmap_min_addr_handler,
1225 .procname = "numa_zonelist_order",
1226 .data = &numa_zonelist_order,
1227 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1229 .proc_handler = numa_zonelist_order_handler,
1232 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1233 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1235 .procname = "vdso_enabled",
1236 .data = &vdso_enabled,
1237 .maxlen = sizeof(vdso_enabled),
1239 .proc_handler = proc_dointvec,
1243 #ifdef CONFIG_HIGHMEM
1245 .procname = "highmem_is_dirtyable",
1246 .data = &vm_highmem_is_dirtyable,
1247 .maxlen = sizeof(vm_highmem_is_dirtyable),
1249 .proc_handler = proc_dointvec_minmax,
1255 .procname = "scan_unevictable_pages",
1256 .data = &scan_unevictable_pages,
1257 .maxlen = sizeof(scan_unevictable_pages),
1259 .proc_handler = scan_unevictable_handler,
1261 #ifdef CONFIG_MEMORY_FAILURE
1263 .procname = "memory_failure_early_kill",
1264 .data = &sysctl_memory_failure_early_kill,
1265 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1267 .proc_handler = proc_dointvec_minmax,
1272 .procname = "memory_failure_recovery",
1273 .data = &sysctl_memory_failure_recovery,
1274 .maxlen = sizeof(sysctl_memory_failure_recovery),
1276 .proc_handler = proc_dointvec_minmax,
1283 * NOTE: do not add new entries to this table unless you have read
1284 * Documentation/sysctl/ctl_unnumbered.txt
1289 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1290 static struct ctl_table binfmt_misc_table[] = {
1295 static struct ctl_table fs_table[] = {
1297 .procname = "inode-nr",
1298 .data = &inodes_stat,
1299 .maxlen = 2*sizeof(int),
1301 .proc_handler = proc_dointvec,
1304 .procname = "inode-state",
1305 .data = &inodes_stat,
1306 .maxlen = 7*sizeof(int),
1308 .proc_handler = proc_dointvec,
1311 .procname = "file-nr",
1312 .data = &files_stat,
1313 .maxlen = 3*sizeof(int),
1315 .proc_handler = proc_nr_files,
1318 .procname = "file-max",
1319 .data = &files_stat.max_files,
1320 .maxlen = sizeof(int),
1322 .proc_handler = proc_dointvec,
1325 .procname = "nr_open",
1326 .data = &sysctl_nr_open,
1327 .maxlen = sizeof(int),
1329 .proc_handler = proc_dointvec_minmax,
1330 .extra1 = &sysctl_nr_open_min,
1331 .extra2 = &sysctl_nr_open_max,
1334 .procname = "dentry-state",
1335 .data = &dentry_stat,
1336 .maxlen = 6*sizeof(int),
1338 .proc_handler = proc_dointvec,
1341 .procname = "overflowuid",
1342 .data = &fs_overflowuid,
1343 .maxlen = sizeof(int),
1345 .proc_handler = proc_dointvec_minmax,
1346 .extra1 = &minolduid,
1347 .extra2 = &maxolduid,
1350 .procname = "overflowgid",
1351 .data = &fs_overflowgid,
1352 .maxlen = sizeof(int),
1354 .proc_handler = proc_dointvec_minmax,
1355 .extra1 = &minolduid,
1356 .extra2 = &maxolduid,
1358 #ifdef CONFIG_FILE_LOCKING
1360 .procname = "leases-enable",
1361 .data = &leases_enable,
1362 .maxlen = sizeof(int),
1364 .proc_handler = proc_dointvec,
1367 #ifdef CONFIG_DNOTIFY
1369 .procname = "dir-notify-enable",
1370 .data = &dir_notify_enable,
1371 .maxlen = sizeof(int),
1373 .proc_handler = proc_dointvec,
1377 #ifdef CONFIG_FILE_LOCKING
1379 .procname = "lease-break-time",
1380 .data = &lease_break_time,
1381 .maxlen = sizeof(int),
1383 .proc_handler = proc_dointvec,
1388 .procname = "aio-nr",
1390 .maxlen = sizeof(aio_nr),
1392 .proc_handler = proc_doulongvec_minmax,
1395 .procname = "aio-max-nr",
1396 .data = &aio_max_nr,
1397 .maxlen = sizeof(aio_max_nr),
1399 .proc_handler = proc_doulongvec_minmax,
1401 #endif /* CONFIG_AIO */
1402 #ifdef CONFIG_INOTIFY_USER
1404 .procname = "inotify",
1406 .child = inotify_table,
1411 .procname = "epoll",
1413 .child = epoll_table,
1418 .procname = "suid_dumpable",
1419 .data = &suid_dumpable,
1420 .maxlen = sizeof(int),
1422 .proc_handler = proc_dointvec_minmax,
1426 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1428 .procname = "binfmt_misc",
1430 .child = binfmt_misc_table,
1434 * NOTE: do not add new entries to this table unless you have read
1435 * Documentation/sysctl/ctl_unnumbered.txt
1440 static struct ctl_table debug_table[] = {
1441 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC)
1443 .procname = "exception-trace",
1444 .data = &show_unhandled_signals,
1445 .maxlen = sizeof(int),
1447 .proc_handler = proc_dointvec
1450 #if defined(CONFIG_OPTPROBES)
1452 .procname = "kprobes-optimization",
1453 .data = &sysctl_kprobes_optimization,
1454 .maxlen = sizeof(int),
1456 .proc_handler = proc_kprobes_optimization_handler,
1464 static struct ctl_table dev_table[] = {
1468 static DEFINE_SPINLOCK(sysctl_lock);
1470 /* called under sysctl_lock */
1471 static int use_table(struct ctl_table_header *p)
1473 if (unlikely(p->unregistering))
1479 /* called under sysctl_lock */
1480 static void unuse_table(struct ctl_table_header *p)
1483 if (unlikely(p->unregistering))
1484 complete(p->unregistering);
1487 /* called under sysctl_lock, will reacquire if has to wait */
1488 static void start_unregistering(struct ctl_table_header *p)
1491 * if p->used is 0, nobody will ever touch that entry again;
1492 * we'll eliminate all paths to it before dropping sysctl_lock
1494 if (unlikely(p->used)) {
1495 struct completion wait;
1496 init_completion(&wait);
1497 p->unregistering = &wait;
1498 spin_unlock(&sysctl_lock);
1499 wait_for_completion(&wait);
1500 spin_lock(&sysctl_lock);
1502 /* anything non-NULL; we'll never dereference it */
1503 p->unregistering = ERR_PTR(-EINVAL);
1506 * do not remove from the list until nobody holds it; walking the
1507 * list in do_sysctl() relies on that.
1509 list_del_init(&p->ctl_entry);
1512 void sysctl_head_get(struct ctl_table_header *head)
1514 spin_lock(&sysctl_lock);
1516 spin_unlock(&sysctl_lock);
1519 void sysctl_head_put(struct ctl_table_header *head)
1521 spin_lock(&sysctl_lock);
1524 spin_unlock(&sysctl_lock);
1527 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1531 spin_lock(&sysctl_lock);
1532 if (!use_table(head))
1533 head = ERR_PTR(-ENOENT);
1534 spin_unlock(&sysctl_lock);
1538 void sysctl_head_finish(struct ctl_table_header *head)
1542 spin_lock(&sysctl_lock);
1544 spin_unlock(&sysctl_lock);
1547 static struct ctl_table_set *
1548 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1550 struct ctl_table_set *set = &root->default_set;
1552 set = root->lookup(root, namespaces);
1556 static struct list_head *
1557 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1559 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1563 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1564 struct ctl_table_header *prev)
1566 struct ctl_table_root *root;
1567 struct list_head *header_list;
1568 struct ctl_table_header *head;
1569 struct list_head *tmp;
1571 spin_lock(&sysctl_lock);
1574 tmp = &prev->ctl_entry;
1578 tmp = &root_table_header.ctl_entry;
1580 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1582 if (!use_table(head))
1584 spin_unlock(&sysctl_lock);
1589 header_list = lookup_header_list(root, namespaces);
1590 if (tmp != header_list)
1594 root = list_entry(root->root_list.next,
1595 struct ctl_table_root, root_list);
1596 if (root == &sysctl_table_root)
1598 header_list = lookup_header_list(root, namespaces);
1599 } while (list_empty(header_list));
1600 tmp = header_list->next;
1603 spin_unlock(&sysctl_lock);
1607 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1609 return __sysctl_head_next(current->nsproxy, prev);
1612 void register_sysctl_root(struct ctl_table_root *root)
1614 spin_lock(&sysctl_lock);
1615 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1616 spin_unlock(&sysctl_lock);
1620 * sysctl_perm does NOT grant the superuser all rights automatically, because
1621 * some sysctl variables are readonly even to root.
1624 static int test_perm(int mode, int op)
1626 if (!current_euid())
1628 else if (in_egroup_p(0))
1630 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1635 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1640 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1644 if (root->permissions)
1645 mode = root->permissions(root, current->nsproxy, table);
1649 return test_perm(mode, op);
1652 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1654 for (; table->procname; table++) {
1655 table->parent = parent;
1657 sysctl_set_parent(table, table->child);
1661 static __init int sysctl_init(void)
1663 sysctl_set_parent(NULL, root_table);
1664 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1667 err = sysctl_check_table(current->nsproxy, root_table);
1673 core_initcall(sysctl_init);
1675 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1676 struct ctl_table *table)
1678 struct ctl_table *p;
1679 const char *s = branch->procname;
1681 /* branch should have named subdirectory as its first element */
1682 if (!s || !branch->child)
1685 /* ... and nothing else */
1686 if (branch[1].procname)
1689 /* table should contain subdirectory with the same name */
1690 for (p = table; p->procname; p++) {
1693 if (p->procname && strcmp(p->procname, s) == 0)
1699 /* see if attaching q to p would be an improvement */
1700 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1702 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1703 struct ctl_table *next;
1705 int not_in_parent = !p->attached_by;
1707 while ((next = is_branch_in(by, to)) != NULL) {
1708 if (by == q->attached_by)
1710 if (to == p->attached_by)
1716 if (is_better && not_in_parent) {
1717 q->attached_by = by;
1718 q->attached_to = to;
1724 * __register_sysctl_paths - register a sysctl hierarchy
1725 * @root: List of sysctl headers to register on
1726 * @namespaces: Data to compute which lists of sysctl entries are visible
1727 * @path: The path to the directory the sysctl table is in.
1728 * @table: the top-level table structure
1730 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1731 * array. A completely 0 filled entry terminates the table.
1733 * The members of the &struct ctl_table structure are used as follows:
1735 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1736 * enter a sysctl file
1738 * data - a pointer to data for use by proc_handler
1740 * maxlen - the maximum size in bytes of the data
1742 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1744 * child - a pointer to the child sysctl table if this entry is a directory, or
1747 * proc_handler - the text handler routine (described below)
1749 * de - for internal use by the sysctl routines
1751 * extra1, extra2 - extra pointers usable by the proc handler routines
1753 * Leaf nodes in the sysctl tree will be represented by a single file
1754 * under /proc; non-leaf nodes will be represented by directories.
1756 * sysctl(2) can automatically manage read and write requests through
1757 * the sysctl table. The data and maxlen fields of the ctl_table
1758 * struct enable minimal validation of the values being written to be
1759 * performed, and the mode field allows minimal authentication.
1761 * There must be a proc_handler routine for any terminal nodes
1762 * mirrored under /proc/sys (non-terminals are handled by a built-in
1763 * directory handler). Several default handlers are available to
1764 * cover common cases -
1766 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1767 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1768 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1770 * It is the handler's job to read the input buffer from user memory
1771 * and process it. The handler should return 0 on success.
1773 * This routine returns %NULL on a failure to register, and a pointer
1774 * to the table header on success.
1776 struct ctl_table_header *__register_sysctl_paths(
1777 struct ctl_table_root *root,
1778 struct nsproxy *namespaces,
1779 const struct ctl_path *path, struct ctl_table *table)
1781 struct ctl_table_header *header;
1782 struct ctl_table *new, **prevp;
1783 unsigned int n, npath;
1784 struct ctl_table_set *set;
1786 /* Count the path components */
1787 for (npath = 0; path[npath].procname; ++npath)
1791 * For each path component, allocate a 2-element ctl_table array.
1792 * The first array element will be filled with the sysctl entry
1793 * for this, the second will be the sentinel (procname == 0).
1795 * We allocate everything in one go so that we don't have to
1796 * worry about freeing additional memory in unregister_sysctl_table.
1798 header = kzalloc(sizeof(struct ctl_table_header) +
1799 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1803 new = (struct ctl_table *) (header + 1);
1805 /* Now connect the dots */
1806 prevp = &header->ctl_table;
1807 for (n = 0; n < npath; ++n, ++path) {
1808 /* Copy the procname */
1809 new->procname = path->procname;
1813 prevp = &new->child;
1818 header->ctl_table_arg = table;
1820 INIT_LIST_HEAD(&header->ctl_entry);
1822 header->unregistering = NULL;
1823 header->root = root;
1824 sysctl_set_parent(NULL, header->ctl_table);
1826 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1827 if (sysctl_check_table(namespaces, header->ctl_table)) {
1832 spin_lock(&sysctl_lock);
1833 header->set = lookup_header_set(root, namespaces);
1834 header->attached_by = header->ctl_table;
1835 header->attached_to = root_table;
1836 header->parent = &root_table_header;
1837 for (set = header->set; set; set = set->parent) {
1838 struct ctl_table_header *p;
1839 list_for_each_entry(p, &set->list, ctl_entry) {
1840 if (p->unregistering)
1842 try_attach(p, header);
1845 header->parent->count++;
1846 list_add_tail(&header->ctl_entry, &header->set->list);
1847 spin_unlock(&sysctl_lock);
1853 * register_sysctl_table_path - register a sysctl table hierarchy
1854 * @path: The path to the directory the sysctl table is in.
1855 * @table: the top-level table structure
1857 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1858 * array. A completely 0 filled entry terminates the table.
1860 * See __register_sysctl_paths for more details.
1862 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1863 struct ctl_table *table)
1865 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1870 * register_sysctl_table - register a sysctl table hierarchy
1871 * @table: the top-level table structure
1873 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1874 * array. A completely 0 filled entry terminates the table.
1876 * See register_sysctl_paths for more details.
1878 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1880 static const struct ctl_path null_path[] = { {} };
1882 return register_sysctl_paths(null_path, table);
1886 * unregister_sysctl_table - unregister a sysctl table hierarchy
1887 * @header: the header returned from register_sysctl_table
1889 * Unregisters the sysctl table and all children. proc entries may not
1890 * actually be removed until they are no longer used by anyone.
1892 void unregister_sysctl_table(struct ctl_table_header * header)
1899 spin_lock(&sysctl_lock);
1900 start_unregistering(header);
1901 if (!--header->parent->count) {
1903 kfree(header->parent);
1905 if (!--header->count)
1907 spin_unlock(&sysctl_lock);
1910 int sysctl_is_seen(struct ctl_table_header *p)
1912 struct ctl_table_set *set = p->set;
1914 spin_lock(&sysctl_lock);
1915 if (p->unregistering)
1917 else if (!set->is_seen)
1920 res = set->is_seen(set);
1921 spin_unlock(&sysctl_lock);
1925 void setup_sysctl_set(struct ctl_table_set *p,
1926 struct ctl_table_set *parent,
1927 int (*is_seen)(struct ctl_table_set *))
1929 INIT_LIST_HEAD(&p->list);
1930 p->parent = parent ? parent : &sysctl_table_root.default_set;
1931 p->is_seen = is_seen;
1934 #else /* !CONFIG_SYSCTL */
1935 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1940 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1941 struct ctl_table *table)
1946 void unregister_sysctl_table(struct ctl_table_header * table)
1950 void setup_sysctl_set(struct ctl_table_set *p,
1951 struct ctl_table_set *parent,
1952 int (*is_seen)(struct ctl_table_set *))
1956 void sysctl_head_put(struct ctl_table_header *head)
1960 #endif /* CONFIG_SYSCTL */
1966 #ifdef CONFIG_PROC_SYSCTL
1968 static int _proc_do_string(void* data, int maxlen, int write,
1969 void __user *buffer,
1970 size_t *lenp, loff_t *ppos)
1976 if (!data || !maxlen || !*lenp) {
1984 while (len < *lenp) {
1985 if (get_user(c, p++))
1987 if (c == 0 || c == '\n')
1993 if(copy_from_user(data, buffer, len))
1995 ((char *) data)[len] = 0;
2013 if(copy_to_user(buffer, data, len))
2016 if(put_user('\n', ((char __user *) buffer) + len))
2027 * proc_dostring - read a string sysctl
2028 * @table: the sysctl table
2029 * @write: %TRUE if this is a write to the sysctl file
2030 * @buffer: the user buffer
2031 * @lenp: the size of the user buffer
2032 * @ppos: file position
2034 * Reads/writes a string from/to the user buffer. If the kernel
2035 * buffer provided is not large enough to hold the string, the
2036 * string is truncated. The copied string is %NULL-terminated.
2037 * If the string is being read by the user process, it is copied
2038 * and a newline '\n' is added. It is truncated if the buffer is
2041 * Returns 0 on success.
2043 int proc_dostring(struct ctl_table *table, int write,
2044 void __user *buffer, size_t *lenp, loff_t *ppos)
2046 return _proc_do_string(table->data, table->maxlen, write,
2047 buffer, lenp, ppos);
2051 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2053 int write, void *data)
2056 *valp = *negp ? -*lvalp : *lvalp;
2061 *lvalp = (unsigned long)-val;
2064 *lvalp = (unsigned long)val;
2070 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2071 int write, void __user *buffer,
2072 size_t *lenp, loff_t *ppos,
2073 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2074 int write, void *data),
2077 #define TMPBUFLEN 21
2078 int *i, vleft, first = 1, neg;
2082 char buf[TMPBUFLEN], *p;
2083 char __user *s = buffer;
2085 if (!tbl_data || !table->maxlen || !*lenp ||
2086 (*ppos && !write)) {
2091 i = (int *) tbl_data;
2092 vleft = table->maxlen / sizeof(*i);
2096 conv = do_proc_dointvec_conv;
2098 for (; left && vleft--; i++, first=0) {
2113 if (len > sizeof(buf) - 1)
2114 len = sizeof(buf) - 1;
2115 if (copy_from_user(buf, s, len))
2119 if (*p == '-' && left > 1) {
2123 if (*p < '0' || *p > '9')
2126 lval = simple_strtoul(p, &p, 0);
2129 if ((len < left) && *p && !isspace(*p))
2134 if (conv(&neg, &lval, i, 1, data))
2141 if (conv(&neg, &lval, i, 0, data))
2144 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2148 if(copy_to_user(s, buf, len))
2155 if (!write && !first && left) {
2156 if(put_user('\n', s))
2163 if (get_user(c, s++))
2178 static int do_proc_dointvec(struct ctl_table *table, int write,
2179 void __user *buffer, size_t *lenp, loff_t *ppos,
2180 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2181 int write, void *data),
2184 return __do_proc_dointvec(table->data, table, write,
2185 buffer, lenp, ppos, conv, data);
2189 * proc_dointvec - read a vector of integers
2190 * @table: the sysctl table
2191 * @write: %TRUE if this is a write to the sysctl file
2192 * @buffer: the user buffer
2193 * @lenp: the size of the user buffer
2194 * @ppos: file position
2196 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2197 * values from/to the user buffer, treated as an ASCII string.
2199 * Returns 0 on success.
2201 int proc_dointvec(struct ctl_table *table, int write,
2202 void __user *buffer, size_t *lenp, loff_t *ppos)
2204 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2209 * Taint values can only be increased
2210 * This means we can safely use a temporary.
2212 static int proc_taint(struct ctl_table *table, int write,
2213 void __user *buffer, size_t *lenp, loff_t *ppos)
2216 unsigned long tmptaint = get_taint();
2219 if (write && !capable(CAP_SYS_ADMIN))
2224 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2230 * Poor man's atomic or. Not worth adding a primitive
2231 * to everyone's atomic.h for this
2234 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2235 if ((tmptaint >> i) & 1)
2243 struct do_proc_dointvec_minmax_conv_param {
2248 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2250 int write, void *data)
2252 struct do_proc_dointvec_minmax_conv_param *param = data;
2254 int val = *negp ? -*lvalp : *lvalp;
2255 if ((param->min && *param->min > val) ||
2256 (param->max && *param->max < val))
2263 *lvalp = (unsigned long)-val;
2266 *lvalp = (unsigned long)val;
2273 * proc_dointvec_minmax - read a vector of integers with min/max values
2274 * @table: the sysctl table
2275 * @write: %TRUE if this is a write to the sysctl file
2276 * @buffer: the user buffer
2277 * @lenp: the size of the user buffer
2278 * @ppos: file position
2280 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2281 * values from/to the user buffer, treated as an ASCII string.
2283 * This routine will ensure the values are within the range specified by
2284 * table->extra1 (min) and table->extra2 (max).
2286 * Returns 0 on success.
2288 int proc_dointvec_minmax(struct ctl_table *table, int write,
2289 void __user *buffer, size_t *lenp, loff_t *ppos)
2291 struct do_proc_dointvec_minmax_conv_param param = {
2292 .min = (int *) table->extra1,
2293 .max = (int *) table->extra2,
2295 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2296 do_proc_dointvec_minmax_conv, ¶m);
2299 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2300 void __user *buffer,
2301 size_t *lenp, loff_t *ppos,
2302 unsigned long convmul,
2303 unsigned long convdiv)
2305 #define TMPBUFLEN 21
2306 unsigned long *i, *min, *max, val;
2307 int vleft, first=1, neg;
2309 char buf[TMPBUFLEN], *p;
2310 char __user *s = buffer;
2312 if (!data || !table->maxlen || !*lenp ||
2313 (*ppos && !write)) {
2318 i = (unsigned long *) data;
2319 min = (unsigned long *) table->extra1;
2320 max = (unsigned long *) table->extra2;
2321 vleft = table->maxlen / sizeof(unsigned long);
2324 for (; left && vleft--; i++, min++, max++, first=0) {
2339 if (len > TMPBUFLEN-1)
2341 if (copy_from_user(buf, s, len))
2345 if (*p == '-' && left > 1) {
2349 if (*p < '0' || *p > '9')
2351 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2353 if ((len < left) && *p && !isspace(*p))
2362 if ((min && val < *min) || (max && val > *max))
2369 sprintf(p, "%lu", convdiv * (*i) / convmul);
2373 if(copy_to_user(s, buf, len))
2380 if (!write && !first && left) {
2381 if(put_user('\n', s))
2388 if (get_user(c, s++))
2403 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2404 void __user *buffer,
2405 size_t *lenp, loff_t *ppos,
2406 unsigned long convmul,
2407 unsigned long convdiv)
2409 return __do_proc_doulongvec_minmax(table->data, table, write,
2410 buffer, lenp, ppos, convmul, convdiv);
2414 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2415 * @table: the sysctl table
2416 * @write: %TRUE if this is a write to the sysctl file
2417 * @buffer: the user buffer
2418 * @lenp: the size of the user buffer
2419 * @ppos: file position
2421 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2422 * values from/to the user buffer, treated as an ASCII string.
2424 * This routine will ensure the values are within the range specified by
2425 * table->extra1 (min) and table->extra2 (max).
2427 * Returns 0 on success.
2429 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2430 void __user *buffer, size_t *lenp, loff_t *ppos)
2432 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2436 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2437 * @table: the sysctl table
2438 * @write: %TRUE if this is a write to the sysctl file
2439 * @buffer: the user buffer
2440 * @lenp: the size of the user buffer
2441 * @ppos: file position
2443 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2444 * values from/to the user buffer, treated as an ASCII string. The values
2445 * are treated as milliseconds, and converted to jiffies when they are stored.
2447 * This routine will ensure the values are within the range specified by
2448 * table->extra1 (min) and table->extra2 (max).
2450 * Returns 0 on success.
2452 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2453 void __user *buffer,
2454 size_t *lenp, loff_t *ppos)
2456 return do_proc_doulongvec_minmax(table, write, buffer,
2457 lenp, ppos, HZ, 1000l);
2461 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2463 int write, void *data)
2466 if (*lvalp > LONG_MAX / HZ)
2468 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2474 lval = (unsigned long)-val;
2477 lval = (unsigned long)val;
2484 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2486 int write, void *data)
2489 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2491 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2497 lval = (unsigned long)-val;
2500 lval = (unsigned long)val;
2502 *lvalp = jiffies_to_clock_t(lval);
2507 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2509 int write, void *data)
2512 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2518 lval = (unsigned long)-val;
2521 lval = (unsigned long)val;
2523 *lvalp = jiffies_to_msecs(lval);
2529 * proc_dointvec_jiffies - read a vector of integers as seconds
2530 * @table: the sysctl table
2531 * @write: %TRUE if this is a write to the sysctl file
2532 * @buffer: the user buffer
2533 * @lenp: the size of the user buffer
2534 * @ppos: file position
2536 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2537 * values from/to the user buffer, treated as an ASCII string.
2538 * The values read are assumed to be in seconds, and are converted into
2541 * Returns 0 on success.
2543 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2544 void __user *buffer, size_t *lenp, loff_t *ppos)
2546 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2547 do_proc_dointvec_jiffies_conv,NULL);
2551 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2552 * @table: the sysctl table
2553 * @write: %TRUE if this is a write to the sysctl file
2554 * @buffer: the user buffer
2555 * @lenp: the size of the user buffer
2556 * @ppos: pointer to the file position
2558 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2559 * values from/to the user buffer, treated as an ASCII string.
2560 * The values read are assumed to be in 1/USER_HZ seconds, and
2561 * are converted into jiffies.
2563 * Returns 0 on success.
2565 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2566 void __user *buffer, size_t *lenp, loff_t *ppos)
2568 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2569 do_proc_dointvec_userhz_jiffies_conv,NULL);
2573 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2574 * @table: the sysctl table
2575 * @write: %TRUE if this is a write to the sysctl file
2576 * @buffer: the user buffer
2577 * @lenp: the size of the user buffer
2578 * @ppos: file position
2579 * @ppos: the current position in the file
2581 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2582 * values from/to the user buffer, treated as an ASCII string.
2583 * The values read are assumed to be in 1/1000 seconds, and
2584 * are converted into jiffies.
2586 * Returns 0 on success.
2588 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2589 void __user *buffer, size_t *lenp, loff_t *ppos)
2591 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2592 do_proc_dointvec_ms_jiffies_conv, NULL);
2595 static int proc_do_cad_pid(struct ctl_table *table, int write,
2596 void __user *buffer, size_t *lenp, loff_t *ppos)
2598 struct pid *new_pid;
2602 tmp = pid_vnr(cad_pid);
2604 r = __do_proc_dointvec(&tmp, table, write, buffer,
2605 lenp, ppos, NULL, NULL);
2609 new_pid = find_get_pid(tmp);
2613 put_pid(xchg(&cad_pid, new_pid));
2617 #else /* CONFIG_PROC_FS */
2619 int proc_dostring(struct ctl_table *table, int write,
2620 void __user *buffer, size_t *lenp, loff_t *ppos)
2625 int proc_dointvec(struct ctl_table *table, int write,
2626 void __user *buffer, size_t *lenp, loff_t *ppos)
2631 int proc_dointvec_minmax(struct ctl_table *table, int write,
2632 void __user *buffer, size_t *lenp, loff_t *ppos)
2637 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2638 void __user *buffer, size_t *lenp, loff_t *ppos)
2643 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2644 void __user *buffer, size_t *lenp, loff_t *ppos)
2649 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2650 void __user *buffer, size_t *lenp, loff_t *ppos)
2655 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2656 void __user *buffer, size_t *lenp, loff_t *ppos)
2661 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2662 void __user *buffer,
2663 size_t *lenp, loff_t *ppos)
2669 #endif /* CONFIG_PROC_FS */
2672 * No sense putting this after each symbol definition, twice,
2673 * exception granted :-)
2675 EXPORT_SYMBOL(proc_dointvec);
2676 EXPORT_SYMBOL(proc_dointvec_jiffies);
2677 EXPORT_SYMBOL(proc_dointvec_minmax);
2678 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2679 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2680 EXPORT_SYMBOL(proc_dostring);
2681 EXPORT_SYMBOL(proc_doulongvec_minmax);
2682 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2683 EXPORT_SYMBOL(register_sysctl_table);
2684 EXPORT_SYMBOL(register_sysctl_paths);
2685 EXPORT_SYMBOL(unregister_sysctl_table);