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/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/ctype.h>
29 #include <linux/kmemcheck.h>
31 #include <linux/init.h>
32 #include <linux/kernel.h>
33 #include <linux/kobject.h>
34 #include <linux/net.h>
35 #include <linux/sysrq.h>
36 #include <linux/highuid.h>
37 #include <linux/writeback.h>
38 #include <linux/ratelimit.h>
39 #include <linux/hugetlb.h>
40 #include <linux/initrd.h>
41 #include <linux/key.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/vmstat.h>
47 #include <linux/nfs_fs.h>
48 #include <linux/acpi.h>
49 #include <linux/reboot.h>
50 #include <linux/ftrace.h>
51 #include <linux/slow-work.h>
52 #include <linux/perf_event.h>
54 #include <asm/uaccess.h>
55 #include <asm/processor.h>
59 #include <asm/stacktrace.h>
64 #if defined(CONFIG_SYSCTL)
66 /* External variables not in a header file. */
68 extern int print_fatal_signals;
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;
90 #ifdef CONFIG_RCU_TORTURE_TEST
91 extern int rcutorture_runnable;
92 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
94 extern int blk_iopoll_enabled;
97 /* Constants used for minimum and maximum */
98 #ifdef CONFIG_DETECT_SOFTLOCKUP
99 static int sixty = 60;
100 static int neg_one = -1;
104 static int __maybe_unused one = 1;
105 static int __maybe_unused two = 2;
106 static unsigned long one_ul = 1;
107 static int one_hundred = 100;
109 static int ten_thousand = 10000;
112 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
113 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
115 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
116 static int maxolduid = 65535;
117 static int minolduid;
118 static int min_percpu_pagelist_fract = 8;
120 static int ngroups_max = NGROUPS_MAX;
122 #ifdef CONFIG_MODULES
123 extern char modprobe_path[];
124 extern int modules_disabled;
126 #ifdef CONFIG_CHR_DEV_SG
127 extern int sg_big_buff;
131 #include <asm/system.h>
134 #ifdef CONFIG_SPARC64
135 extern int sysctl_tsb_ratio;
139 extern int pwrsw_enabled;
140 extern int unaligned_enabled;
144 #ifdef CONFIG_MATHEMU
145 extern int sysctl_ieee_emulation_warnings;
147 extern int sysctl_userprocess_debug;
148 extern int spin_retry;
151 #ifdef CONFIG_BSD_PROCESS_ACCT
152 extern int acct_parm[];
156 extern int no_unaligned_warning;
157 extern int unaligned_dump_stack;
160 extern struct ratelimit_state printk_ratelimit_state;
162 #ifdef CONFIG_RT_MUTEXES
163 extern int max_lock_depth;
166 #ifdef CONFIG_PROC_SYSCTL
167 static int proc_do_cad_pid(struct ctl_table *table, int write,
168 void __user *buffer, size_t *lenp, loff_t *ppos);
169 static int proc_taint(struct ctl_table *table, int write,
170 void __user *buffer, size_t *lenp, loff_t *ppos);
173 static struct ctl_table root_table[];
174 static struct ctl_table_root sysctl_table_root;
175 static struct ctl_table_header root_table_header = {
177 .ctl_table = root_table,
178 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
179 .root = &sysctl_table_root,
180 .set = &sysctl_table_root.default_set,
182 static struct ctl_table_root sysctl_table_root = {
183 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
184 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
187 static struct ctl_table kern_table[];
188 static struct ctl_table vm_table[];
189 static struct ctl_table fs_table[];
190 static struct ctl_table debug_table[];
191 static struct ctl_table dev_table[];
192 extern struct ctl_table random_table[];
193 #ifdef CONFIG_INOTIFY_USER
194 extern struct ctl_table inotify_table[];
197 extern struct ctl_table epoll_table[];
200 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
201 int sysctl_legacy_va_layout;
204 extern int prove_locking;
205 extern int lock_stat;
207 /* The default sysctl tables: */
209 static struct ctl_table root_table[] = {
211 .procname = "kernel",
228 .child = debug_table,
236 * NOTE: do not add new entries to this table unless you have read
237 * Documentation/sysctl/ctl_unnumbered.txt
242 #ifdef CONFIG_SCHED_DEBUG
243 static int min_sched_granularity_ns = 100000; /* 100 usecs */
244 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
245 static int min_wakeup_granularity_ns; /* 0 usecs */
246 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
247 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
248 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
249 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
250 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
253 static struct ctl_table kern_table[] = {
255 .procname = "sched_child_runs_first",
256 .data = &sysctl_sched_child_runs_first,
257 .maxlen = sizeof(unsigned int),
259 .proc_handler = proc_dointvec,
261 #ifdef CONFIG_SCHED_DEBUG
263 .procname = "sched_min_granularity_ns",
264 .data = &sysctl_sched_min_granularity,
265 .maxlen = sizeof(unsigned int),
267 .proc_handler = sched_proc_update_handler,
268 .extra1 = &min_sched_granularity_ns,
269 .extra2 = &max_sched_granularity_ns,
272 .procname = "sched_latency_ns",
273 .data = &sysctl_sched_latency,
274 .maxlen = sizeof(unsigned int),
276 .proc_handler = sched_proc_update_handler,
277 .extra1 = &min_sched_granularity_ns,
278 .extra2 = &max_sched_granularity_ns,
281 .procname = "sched_wakeup_granularity_ns",
282 .data = &sysctl_sched_wakeup_granularity,
283 .maxlen = sizeof(unsigned int),
285 .proc_handler = sched_proc_update_handler,
286 .extra1 = &min_wakeup_granularity_ns,
287 .extra2 = &max_wakeup_granularity_ns,
290 .procname = "sched_shares_ratelimit",
291 .data = &sysctl_sched_shares_ratelimit,
292 .maxlen = sizeof(unsigned int),
294 .proc_handler = sched_proc_update_handler,
295 .extra1 = &min_sched_shares_ratelimit,
296 .extra2 = &max_sched_shares_ratelimit,
299 .procname = "sched_tunable_scaling",
300 .data = &sysctl_sched_tunable_scaling,
301 .maxlen = sizeof(enum sched_tunable_scaling),
303 .proc_handler = sched_proc_update_handler,
304 .extra1 = &min_sched_tunable_scaling,
305 .extra2 = &max_sched_tunable_scaling,
308 .procname = "sched_shares_thresh",
309 .data = &sysctl_sched_shares_thresh,
310 .maxlen = sizeof(unsigned int),
312 .proc_handler = proc_dointvec_minmax,
316 .procname = "sched_migration_cost",
317 .data = &sysctl_sched_migration_cost,
318 .maxlen = sizeof(unsigned int),
320 .proc_handler = proc_dointvec,
323 .procname = "sched_nr_migrate",
324 .data = &sysctl_sched_nr_migrate,
325 .maxlen = sizeof(unsigned int),
327 .proc_handler = proc_dointvec,
330 .procname = "sched_time_avg",
331 .data = &sysctl_sched_time_avg,
332 .maxlen = sizeof(unsigned int),
334 .proc_handler = proc_dointvec,
337 .procname = "timer_migration",
338 .data = &sysctl_timer_migration,
339 .maxlen = sizeof(unsigned int),
341 .proc_handler = proc_dointvec_minmax,
347 .procname = "sched_rt_period_us",
348 .data = &sysctl_sched_rt_period,
349 .maxlen = sizeof(unsigned int),
351 .proc_handler = sched_rt_handler,
354 .procname = "sched_rt_runtime_us",
355 .data = &sysctl_sched_rt_runtime,
356 .maxlen = sizeof(int),
358 .proc_handler = sched_rt_handler,
361 .procname = "sched_compat_yield",
362 .data = &sysctl_sched_compat_yield,
363 .maxlen = sizeof(unsigned int),
365 .proc_handler = proc_dointvec,
367 #ifdef CONFIG_PROVE_LOCKING
369 .procname = "prove_locking",
370 .data = &prove_locking,
371 .maxlen = sizeof(int),
373 .proc_handler = proc_dointvec,
376 #ifdef CONFIG_LOCK_STAT
378 .procname = "lock_stat",
380 .maxlen = sizeof(int),
382 .proc_handler = proc_dointvec,
387 .data = &panic_timeout,
388 .maxlen = sizeof(int),
390 .proc_handler = proc_dointvec,
393 .procname = "core_uses_pid",
394 .data = &core_uses_pid,
395 .maxlen = sizeof(int),
397 .proc_handler = proc_dointvec,
400 .procname = "core_pattern",
401 .data = core_pattern,
402 .maxlen = CORENAME_MAX_SIZE,
404 .proc_handler = proc_dostring,
407 .procname = "core_pipe_limit",
408 .data = &core_pipe_limit,
409 .maxlen = sizeof(unsigned int),
411 .proc_handler = proc_dointvec,
413 #ifdef CONFIG_PROC_SYSCTL
415 .procname = "tainted",
416 .maxlen = sizeof(long),
418 .proc_handler = proc_taint,
421 #ifdef CONFIG_LATENCYTOP
423 .procname = "latencytop",
424 .data = &latencytop_enabled,
425 .maxlen = sizeof(int),
427 .proc_handler = proc_dointvec,
430 #ifdef CONFIG_BLK_DEV_INITRD
432 .procname = "real-root-dev",
433 .data = &real_root_dev,
434 .maxlen = sizeof(int),
436 .proc_handler = proc_dointvec,
440 .procname = "print-fatal-signals",
441 .data = &print_fatal_signals,
442 .maxlen = sizeof(int),
444 .proc_handler = proc_dointvec,
448 .procname = "reboot-cmd",
449 .data = reboot_command,
452 .proc_handler = proc_dostring,
455 .procname = "stop-a",
456 .data = &stop_a_enabled,
457 .maxlen = sizeof (int),
459 .proc_handler = proc_dointvec,
462 .procname = "scons-poweroff",
463 .data = &scons_pwroff,
464 .maxlen = sizeof (int),
466 .proc_handler = proc_dointvec,
469 #ifdef CONFIG_SPARC64
471 .procname = "tsb-ratio",
472 .data = &sysctl_tsb_ratio,
473 .maxlen = sizeof (int),
475 .proc_handler = proc_dointvec,
480 .procname = "soft-power",
481 .data = &pwrsw_enabled,
482 .maxlen = sizeof (int),
484 .proc_handler = proc_dointvec,
487 .procname = "unaligned-trap",
488 .data = &unaligned_enabled,
489 .maxlen = sizeof (int),
491 .proc_handler = proc_dointvec,
495 .procname = "ctrl-alt-del",
497 .maxlen = sizeof(int),
499 .proc_handler = proc_dointvec,
501 #ifdef CONFIG_FUNCTION_TRACER
503 .procname = "ftrace_enabled",
504 .data = &ftrace_enabled,
505 .maxlen = sizeof(int),
507 .proc_handler = ftrace_enable_sysctl,
510 #ifdef CONFIG_STACK_TRACER
512 .procname = "stack_tracer_enabled",
513 .data = &stack_tracer_enabled,
514 .maxlen = sizeof(int),
516 .proc_handler = stack_trace_sysctl,
519 #ifdef CONFIG_TRACING
521 .procname = "ftrace_dump_on_oops",
522 .data = &ftrace_dump_on_oops,
523 .maxlen = sizeof(int),
525 .proc_handler = proc_dointvec,
528 #ifdef CONFIG_MODULES
530 .procname = "modprobe",
531 .data = &modprobe_path,
532 .maxlen = KMOD_PATH_LEN,
534 .proc_handler = proc_dostring,
537 .procname = "modules_disabled",
538 .data = &modules_disabled,
539 .maxlen = sizeof(int),
541 /* only handle a transition from default "0" to "1" */
542 .proc_handler = proc_dointvec_minmax,
547 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
549 .procname = "hotplug",
550 .data = &uevent_helper,
551 .maxlen = UEVENT_HELPER_PATH_LEN,
553 .proc_handler = proc_dostring,
556 #ifdef CONFIG_CHR_DEV_SG
558 .procname = "sg-big-buff",
559 .data = &sg_big_buff,
560 .maxlen = sizeof (int),
562 .proc_handler = proc_dointvec,
565 #ifdef CONFIG_BSD_PROCESS_ACCT
569 .maxlen = 3*sizeof(int),
571 .proc_handler = proc_dointvec,
574 #ifdef CONFIG_MAGIC_SYSRQ
577 .data = &__sysrq_enabled,
578 .maxlen = sizeof (int),
580 .proc_handler = proc_dointvec,
583 #ifdef CONFIG_PROC_SYSCTL
585 .procname = "cad_pid",
587 .maxlen = sizeof (int),
589 .proc_handler = proc_do_cad_pid,
593 .procname = "threads-max",
594 .data = &max_threads,
595 .maxlen = sizeof(int),
597 .proc_handler = proc_dointvec,
600 .procname = "random",
602 .child = random_table,
605 .procname = "overflowuid",
606 .data = &overflowuid,
607 .maxlen = sizeof(int),
609 .proc_handler = proc_dointvec_minmax,
610 .extra1 = &minolduid,
611 .extra2 = &maxolduid,
614 .procname = "overflowgid",
615 .data = &overflowgid,
616 .maxlen = sizeof(int),
618 .proc_handler = proc_dointvec_minmax,
619 .extra1 = &minolduid,
620 .extra2 = &maxolduid,
623 #ifdef CONFIG_MATHEMU
625 .procname = "ieee_emulation_warnings",
626 .data = &sysctl_ieee_emulation_warnings,
627 .maxlen = sizeof(int),
629 .proc_handler = proc_dointvec,
633 .procname = "userprocess_debug",
634 .data = &sysctl_userprocess_debug,
635 .maxlen = sizeof(int),
637 .proc_handler = proc_dointvec,
641 .procname = "pid_max",
643 .maxlen = sizeof (int),
645 .proc_handler = proc_dointvec_minmax,
646 .extra1 = &pid_max_min,
647 .extra2 = &pid_max_max,
650 .procname = "panic_on_oops",
651 .data = &panic_on_oops,
652 .maxlen = sizeof(int),
654 .proc_handler = proc_dointvec,
656 #if defined CONFIG_PRINTK
658 .procname = "printk",
659 .data = &console_loglevel,
660 .maxlen = 4*sizeof(int),
662 .proc_handler = proc_dointvec,
665 .procname = "printk_ratelimit",
666 .data = &printk_ratelimit_state.interval,
667 .maxlen = sizeof(int),
669 .proc_handler = proc_dointvec_jiffies,
672 .procname = "printk_ratelimit_burst",
673 .data = &printk_ratelimit_state.burst,
674 .maxlen = sizeof(int),
676 .proc_handler = proc_dointvec,
679 .procname = "printk_delay",
680 .data = &printk_delay_msec,
681 .maxlen = sizeof(int),
683 .proc_handler = proc_dointvec_minmax,
685 .extra2 = &ten_thousand,
689 .procname = "ngroups_max",
690 .data = &ngroups_max,
691 .maxlen = sizeof (int),
693 .proc_handler = proc_dointvec,
695 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
697 .procname = "unknown_nmi_panic",
698 .data = &unknown_nmi_panic,
699 .maxlen = sizeof (int),
701 .proc_handler = proc_dointvec,
704 .procname = "nmi_watchdog",
705 .data = &nmi_watchdog_enabled,
706 .maxlen = sizeof (int),
708 .proc_handler = proc_nmi_enabled,
711 #if defined(CONFIG_X86)
713 .procname = "panic_on_unrecovered_nmi",
714 .data = &panic_on_unrecovered_nmi,
715 .maxlen = sizeof(int),
717 .proc_handler = proc_dointvec,
720 .procname = "panic_on_io_nmi",
721 .data = &panic_on_io_nmi,
722 .maxlen = sizeof(int),
724 .proc_handler = proc_dointvec,
727 .procname = "bootloader_type",
728 .data = &bootloader_type,
729 .maxlen = sizeof (int),
731 .proc_handler = proc_dointvec,
734 .procname = "bootloader_version",
735 .data = &bootloader_version,
736 .maxlen = sizeof (int),
738 .proc_handler = proc_dointvec,
741 .procname = "kstack_depth_to_print",
742 .data = &kstack_depth_to_print,
743 .maxlen = sizeof(int),
745 .proc_handler = proc_dointvec,
748 .procname = "io_delay_type",
749 .data = &io_delay_type,
750 .maxlen = sizeof(int),
752 .proc_handler = proc_dointvec,
755 #if defined(CONFIG_MMU)
757 .procname = "randomize_va_space",
758 .data = &randomize_va_space,
759 .maxlen = sizeof(int),
761 .proc_handler = proc_dointvec,
764 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
766 .procname = "spin_retry",
768 .maxlen = sizeof (int),
770 .proc_handler = proc_dointvec,
773 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
775 .procname = "acpi_video_flags",
776 .data = &acpi_realmode_flags,
777 .maxlen = sizeof (unsigned long),
779 .proc_handler = proc_doulongvec_minmax,
784 .procname = "ignore-unaligned-usertrap",
785 .data = &no_unaligned_warning,
786 .maxlen = sizeof (int),
788 .proc_handler = proc_dointvec,
791 .procname = "unaligned-dump-stack",
792 .data = &unaligned_dump_stack,
793 .maxlen = sizeof (int),
795 .proc_handler = proc_dointvec,
798 #ifdef CONFIG_DETECT_SOFTLOCKUP
800 .procname = "softlockup_panic",
801 .data = &softlockup_panic,
802 .maxlen = sizeof(int),
804 .proc_handler = proc_dointvec_minmax,
809 .procname = "softlockup_thresh",
810 .data = &softlockup_thresh,
811 .maxlen = sizeof(int),
813 .proc_handler = proc_dosoftlockup_thresh,
818 #ifdef CONFIG_DETECT_HUNG_TASK
820 .procname = "hung_task_panic",
821 .data = &sysctl_hung_task_panic,
822 .maxlen = sizeof(int),
824 .proc_handler = proc_dointvec_minmax,
829 .procname = "hung_task_check_count",
830 .data = &sysctl_hung_task_check_count,
831 .maxlen = sizeof(unsigned long),
833 .proc_handler = proc_doulongvec_minmax,
836 .procname = "hung_task_timeout_secs",
837 .data = &sysctl_hung_task_timeout_secs,
838 .maxlen = sizeof(unsigned long),
840 .proc_handler = proc_dohung_task_timeout_secs,
843 .procname = "hung_task_warnings",
844 .data = &sysctl_hung_task_warnings,
845 .maxlen = sizeof(unsigned long),
847 .proc_handler = proc_doulongvec_minmax,
852 .procname = "compat-log",
854 .maxlen = sizeof (int),
856 .proc_handler = proc_dointvec,
859 #ifdef CONFIG_RT_MUTEXES
861 .procname = "max_lock_depth",
862 .data = &max_lock_depth,
863 .maxlen = sizeof(int),
865 .proc_handler = proc_dointvec,
869 .procname = "poweroff_cmd",
870 .data = &poweroff_cmd,
871 .maxlen = POWEROFF_CMD_PATH_LEN,
873 .proc_handler = proc_dostring,
879 .child = key_sysctls,
882 #ifdef CONFIG_RCU_TORTURE_TEST
884 .procname = "rcutorture_runnable",
885 .data = &rcutorture_runnable,
886 .maxlen = sizeof(int),
888 .proc_handler = proc_dointvec,
891 #ifdef CONFIG_SLOW_WORK
893 .procname = "slow-work",
895 .child = slow_work_sysctls,
898 #ifdef CONFIG_PERF_EVENTS
900 .procname = "perf_event_paranoid",
901 .data = &sysctl_perf_event_paranoid,
902 .maxlen = sizeof(sysctl_perf_event_paranoid),
904 .proc_handler = proc_dointvec,
907 .procname = "perf_event_mlock_kb",
908 .data = &sysctl_perf_event_mlock,
909 .maxlen = sizeof(sysctl_perf_event_mlock),
911 .proc_handler = proc_dointvec,
914 .procname = "perf_event_max_sample_rate",
915 .data = &sysctl_perf_event_sample_rate,
916 .maxlen = sizeof(sysctl_perf_event_sample_rate),
918 .proc_handler = proc_dointvec,
921 #ifdef CONFIG_KMEMCHECK
923 .procname = "kmemcheck",
924 .data = &kmemcheck_enabled,
925 .maxlen = sizeof(int),
927 .proc_handler = proc_dointvec,
932 .procname = "blk_iopoll",
933 .data = &blk_iopoll_enabled,
934 .maxlen = sizeof(int),
936 .proc_handler = proc_dointvec,
940 * NOTE: do not add new entries to this table unless you have read
941 * Documentation/sysctl/ctl_unnumbered.txt
946 static struct ctl_table vm_table[] = {
948 .procname = "overcommit_memory",
949 .data = &sysctl_overcommit_memory,
950 .maxlen = sizeof(sysctl_overcommit_memory),
952 .proc_handler = proc_dointvec,
955 .procname = "panic_on_oom",
956 .data = &sysctl_panic_on_oom,
957 .maxlen = sizeof(sysctl_panic_on_oom),
959 .proc_handler = proc_dointvec,
962 .procname = "oom_kill_allocating_task",
963 .data = &sysctl_oom_kill_allocating_task,
964 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
966 .proc_handler = proc_dointvec,
969 .procname = "oom_dump_tasks",
970 .data = &sysctl_oom_dump_tasks,
971 .maxlen = sizeof(sysctl_oom_dump_tasks),
973 .proc_handler = proc_dointvec,
976 .procname = "overcommit_ratio",
977 .data = &sysctl_overcommit_ratio,
978 .maxlen = sizeof(sysctl_overcommit_ratio),
980 .proc_handler = proc_dointvec,
983 .procname = "page-cluster",
984 .data = &page_cluster,
985 .maxlen = sizeof(int),
987 .proc_handler = proc_dointvec,
990 .procname = "dirty_background_ratio",
991 .data = &dirty_background_ratio,
992 .maxlen = sizeof(dirty_background_ratio),
994 .proc_handler = dirty_background_ratio_handler,
996 .extra2 = &one_hundred,
999 .procname = "dirty_background_bytes",
1000 .data = &dirty_background_bytes,
1001 .maxlen = sizeof(dirty_background_bytes),
1003 .proc_handler = dirty_background_bytes_handler,
1007 .procname = "dirty_ratio",
1008 .data = &vm_dirty_ratio,
1009 .maxlen = sizeof(vm_dirty_ratio),
1011 .proc_handler = dirty_ratio_handler,
1013 .extra2 = &one_hundred,
1016 .procname = "dirty_bytes",
1017 .data = &vm_dirty_bytes,
1018 .maxlen = sizeof(vm_dirty_bytes),
1020 .proc_handler = dirty_bytes_handler,
1021 .extra1 = &dirty_bytes_min,
1024 .procname = "dirty_writeback_centisecs",
1025 .data = &dirty_writeback_interval,
1026 .maxlen = sizeof(dirty_writeback_interval),
1028 .proc_handler = dirty_writeback_centisecs_handler,
1031 .procname = "dirty_expire_centisecs",
1032 .data = &dirty_expire_interval,
1033 .maxlen = sizeof(dirty_expire_interval),
1035 .proc_handler = proc_dointvec,
1038 .procname = "nr_pdflush_threads",
1039 .data = &nr_pdflush_threads,
1040 .maxlen = sizeof nr_pdflush_threads,
1041 .mode = 0444 /* read-only*/,
1042 .proc_handler = proc_dointvec,
1045 .procname = "swappiness",
1046 .data = &vm_swappiness,
1047 .maxlen = sizeof(vm_swappiness),
1049 .proc_handler = proc_dointvec_minmax,
1051 .extra2 = &one_hundred,
1053 #ifdef CONFIG_HUGETLB_PAGE
1055 .procname = "nr_hugepages",
1057 .maxlen = sizeof(unsigned long),
1059 .proc_handler = hugetlb_sysctl_handler,
1060 .extra1 = (void *)&hugetlb_zero,
1061 .extra2 = (void *)&hugetlb_infinity,
1065 .procname = "nr_hugepages_mempolicy",
1067 .maxlen = sizeof(unsigned long),
1069 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1070 .extra1 = (void *)&hugetlb_zero,
1071 .extra2 = (void *)&hugetlb_infinity,
1075 .procname = "hugetlb_shm_group",
1076 .data = &sysctl_hugetlb_shm_group,
1077 .maxlen = sizeof(gid_t),
1079 .proc_handler = proc_dointvec,
1082 .procname = "hugepages_treat_as_movable",
1083 .data = &hugepages_treat_as_movable,
1084 .maxlen = sizeof(int),
1086 .proc_handler = hugetlb_treat_movable_handler,
1089 .procname = "nr_overcommit_hugepages",
1091 .maxlen = sizeof(unsigned long),
1093 .proc_handler = hugetlb_overcommit_handler,
1094 .extra1 = (void *)&hugetlb_zero,
1095 .extra2 = (void *)&hugetlb_infinity,
1099 .procname = "lowmem_reserve_ratio",
1100 .data = &sysctl_lowmem_reserve_ratio,
1101 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1103 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1106 .procname = "drop_caches",
1107 .data = &sysctl_drop_caches,
1108 .maxlen = sizeof(int),
1110 .proc_handler = drop_caches_sysctl_handler,
1113 .procname = "min_free_kbytes",
1114 .data = &min_free_kbytes,
1115 .maxlen = sizeof(min_free_kbytes),
1117 .proc_handler = min_free_kbytes_sysctl_handler,
1121 .procname = "percpu_pagelist_fraction",
1122 .data = &percpu_pagelist_fraction,
1123 .maxlen = sizeof(percpu_pagelist_fraction),
1125 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1126 .extra1 = &min_percpu_pagelist_fract,
1130 .procname = "max_map_count",
1131 .data = &sysctl_max_map_count,
1132 .maxlen = sizeof(sysctl_max_map_count),
1134 .proc_handler = proc_dointvec_minmax,
1139 .procname = "nr_trim_pages",
1140 .data = &sysctl_nr_trim_pages,
1141 .maxlen = sizeof(sysctl_nr_trim_pages),
1143 .proc_handler = proc_dointvec_minmax,
1148 .procname = "laptop_mode",
1149 .data = &laptop_mode,
1150 .maxlen = sizeof(laptop_mode),
1152 .proc_handler = proc_dointvec_jiffies,
1155 .procname = "block_dump",
1156 .data = &block_dump,
1157 .maxlen = sizeof(block_dump),
1159 .proc_handler = proc_dointvec,
1163 .procname = "vfs_cache_pressure",
1164 .data = &sysctl_vfs_cache_pressure,
1165 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1167 .proc_handler = proc_dointvec,
1170 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1172 .procname = "legacy_va_layout",
1173 .data = &sysctl_legacy_va_layout,
1174 .maxlen = sizeof(sysctl_legacy_va_layout),
1176 .proc_handler = proc_dointvec,
1182 .procname = "zone_reclaim_mode",
1183 .data = &zone_reclaim_mode,
1184 .maxlen = sizeof(zone_reclaim_mode),
1186 .proc_handler = proc_dointvec,
1190 .procname = "min_unmapped_ratio",
1191 .data = &sysctl_min_unmapped_ratio,
1192 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1194 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1196 .extra2 = &one_hundred,
1199 .procname = "min_slab_ratio",
1200 .data = &sysctl_min_slab_ratio,
1201 .maxlen = sizeof(sysctl_min_slab_ratio),
1203 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1205 .extra2 = &one_hundred,
1210 .procname = "stat_interval",
1211 .data = &sysctl_stat_interval,
1212 .maxlen = sizeof(sysctl_stat_interval),
1214 .proc_handler = proc_dointvec_jiffies,
1219 .procname = "mmap_min_addr",
1220 .data = &dac_mmap_min_addr,
1221 .maxlen = sizeof(unsigned long),
1223 .proc_handler = mmap_min_addr_handler,
1228 .procname = "numa_zonelist_order",
1229 .data = &numa_zonelist_order,
1230 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1232 .proc_handler = numa_zonelist_order_handler,
1235 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1236 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1238 .procname = "vdso_enabled",
1239 .data = &vdso_enabled,
1240 .maxlen = sizeof(vdso_enabled),
1242 .proc_handler = proc_dointvec,
1246 #ifdef CONFIG_HIGHMEM
1248 .procname = "highmem_is_dirtyable",
1249 .data = &vm_highmem_is_dirtyable,
1250 .maxlen = sizeof(vm_highmem_is_dirtyable),
1252 .proc_handler = proc_dointvec_minmax,
1258 .procname = "scan_unevictable_pages",
1259 .data = &scan_unevictable_pages,
1260 .maxlen = sizeof(scan_unevictable_pages),
1262 .proc_handler = scan_unevictable_handler,
1264 #ifdef CONFIG_MEMORY_FAILURE
1266 .procname = "memory_failure_early_kill",
1267 .data = &sysctl_memory_failure_early_kill,
1268 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1270 .proc_handler = proc_dointvec_minmax,
1275 .procname = "memory_failure_recovery",
1276 .data = &sysctl_memory_failure_recovery,
1277 .maxlen = sizeof(sysctl_memory_failure_recovery),
1279 .proc_handler = proc_dointvec_minmax,
1286 * NOTE: do not add new entries to this table unless you have read
1287 * Documentation/sysctl/ctl_unnumbered.txt
1292 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1293 static struct ctl_table binfmt_misc_table[] = {
1298 static struct ctl_table fs_table[] = {
1300 .procname = "inode-nr",
1301 .data = &inodes_stat,
1302 .maxlen = 2*sizeof(int),
1304 .proc_handler = proc_dointvec,
1307 .procname = "inode-state",
1308 .data = &inodes_stat,
1309 .maxlen = 7*sizeof(int),
1311 .proc_handler = proc_dointvec,
1314 .procname = "file-nr",
1315 .data = &files_stat,
1316 .maxlen = 3*sizeof(int),
1318 .proc_handler = proc_nr_files,
1321 .procname = "file-max",
1322 .data = &files_stat.max_files,
1323 .maxlen = sizeof(int),
1325 .proc_handler = proc_dointvec,
1328 .procname = "nr_open",
1329 .data = &sysctl_nr_open,
1330 .maxlen = sizeof(int),
1332 .proc_handler = proc_dointvec_minmax,
1333 .extra1 = &sysctl_nr_open_min,
1334 .extra2 = &sysctl_nr_open_max,
1337 .procname = "dentry-state",
1338 .data = &dentry_stat,
1339 .maxlen = 6*sizeof(int),
1341 .proc_handler = proc_dointvec,
1344 .procname = "overflowuid",
1345 .data = &fs_overflowuid,
1346 .maxlen = sizeof(int),
1348 .proc_handler = proc_dointvec_minmax,
1349 .extra1 = &minolduid,
1350 .extra2 = &maxolduid,
1353 .procname = "overflowgid",
1354 .data = &fs_overflowgid,
1355 .maxlen = sizeof(int),
1357 .proc_handler = proc_dointvec_minmax,
1358 .extra1 = &minolduid,
1359 .extra2 = &maxolduid,
1361 #ifdef CONFIG_FILE_LOCKING
1363 .procname = "leases-enable",
1364 .data = &leases_enable,
1365 .maxlen = sizeof(int),
1367 .proc_handler = proc_dointvec,
1370 #ifdef CONFIG_DNOTIFY
1372 .procname = "dir-notify-enable",
1373 .data = &dir_notify_enable,
1374 .maxlen = sizeof(int),
1376 .proc_handler = proc_dointvec,
1380 #ifdef CONFIG_FILE_LOCKING
1382 .procname = "lease-break-time",
1383 .data = &lease_break_time,
1384 .maxlen = sizeof(int),
1386 .proc_handler = proc_dointvec,
1391 .procname = "aio-nr",
1393 .maxlen = sizeof(aio_nr),
1395 .proc_handler = proc_doulongvec_minmax,
1398 .procname = "aio-max-nr",
1399 .data = &aio_max_nr,
1400 .maxlen = sizeof(aio_max_nr),
1402 .proc_handler = proc_doulongvec_minmax,
1404 #endif /* CONFIG_AIO */
1405 #ifdef CONFIG_INOTIFY_USER
1407 .procname = "inotify",
1409 .child = inotify_table,
1414 .procname = "epoll",
1416 .child = epoll_table,
1421 .procname = "suid_dumpable",
1422 .data = &suid_dumpable,
1423 .maxlen = sizeof(int),
1425 .proc_handler = proc_dointvec_minmax,
1429 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1431 .procname = "binfmt_misc",
1433 .child = binfmt_misc_table,
1437 * NOTE: do not add new entries to this table unless you have read
1438 * Documentation/sysctl/ctl_unnumbered.txt
1443 static struct ctl_table debug_table[] = {
1444 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1446 .procname = "exception-trace",
1447 .data = &show_unhandled_signals,
1448 .maxlen = sizeof(int),
1450 .proc_handler = proc_dointvec
1456 static struct ctl_table dev_table[] = {
1460 static DEFINE_SPINLOCK(sysctl_lock);
1462 /* called under sysctl_lock */
1463 static int use_table(struct ctl_table_header *p)
1465 if (unlikely(p->unregistering))
1471 /* called under sysctl_lock */
1472 static void unuse_table(struct ctl_table_header *p)
1475 if (unlikely(p->unregistering))
1476 complete(p->unregistering);
1479 /* called under sysctl_lock, will reacquire if has to wait */
1480 static void start_unregistering(struct ctl_table_header *p)
1483 * if p->used is 0, nobody will ever touch that entry again;
1484 * we'll eliminate all paths to it before dropping sysctl_lock
1486 if (unlikely(p->used)) {
1487 struct completion wait;
1488 init_completion(&wait);
1489 p->unregistering = &wait;
1490 spin_unlock(&sysctl_lock);
1491 wait_for_completion(&wait);
1492 spin_lock(&sysctl_lock);
1494 /* anything non-NULL; we'll never dereference it */
1495 p->unregistering = ERR_PTR(-EINVAL);
1498 * do not remove from the list until nobody holds it; walking the
1499 * list in do_sysctl() relies on that.
1501 list_del_init(&p->ctl_entry);
1504 void sysctl_head_get(struct ctl_table_header *head)
1506 spin_lock(&sysctl_lock);
1508 spin_unlock(&sysctl_lock);
1511 void sysctl_head_put(struct ctl_table_header *head)
1513 spin_lock(&sysctl_lock);
1516 spin_unlock(&sysctl_lock);
1519 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1523 spin_lock(&sysctl_lock);
1524 if (!use_table(head))
1525 head = ERR_PTR(-ENOENT);
1526 spin_unlock(&sysctl_lock);
1530 void sysctl_head_finish(struct ctl_table_header *head)
1534 spin_lock(&sysctl_lock);
1536 spin_unlock(&sysctl_lock);
1539 static struct ctl_table_set *
1540 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1542 struct ctl_table_set *set = &root->default_set;
1544 set = root->lookup(root, namespaces);
1548 static struct list_head *
1549 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1551 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1555 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1556 struct ctl_table_header *prev)
1558 struct ctl_table_root *root;
1559 struct list_head *header_list;
1560 struct ctl_table_header *head;
1561 struct list_head *tmp;
1563 spin_lock(&sysctl_lock);
1566 tmp = &prev->ctl_entry;
1570 tmp = &root_table_header.ctl_entry;
1572 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1574 if (!use_table(head))
1576 spin_unlock(&sysctl_lock);
1581 header_list = lookup_header_list(root, namespaces);
1582 if (tmp != header_list)
1586 root = list_entry(root->root_list.next,
1587 struct ctl_table_root, root_list);
1588 if (root == &sysctl_table_root)
1590 header_list = lookup_header_list(root, namespaces);
1591 } while (list_empty(header_list));
1592 tmp = header_list->next;
1595 spin_unlock(&sysctl_lock);
1599 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1601 return __sysctl_head_next(current->nsproxy, prev);
1604 void register_sysctl_root(struct ctl_table_root *root)
1606 spin_lock(&sysctl_lock);
1607 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1608 spin_unlock(&sysctl_lock);
1612 * sysctl_perm does NOT grant the superuser all rights automatically, because
1613 * some sysctl variables are readonly even to root.
1616 static int test_perm(int mode, int op)
1618 if (!current_euid())
1620 else if (in_egroup_p(0))
1622 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1627 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1632 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1636 if (root->permissions)
1637 mode = root->permissions(root, current->nsproxy, table);
1641 return test_perm(mode, op);
1644 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1646 for (; table->procname; table++) {
1647 table->parent = parent;
1649 sysctl_set_parent(table, table->child);
1653 static __init int sysctl_init(void)
1655 sysctl_set_parent(NULL, root_table);
1656 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1659 err = sysctl_check_table(current->nsproxy, root_table);
1665 core_initcall(sysctl_init);
1667 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1668 struct ctl_table *table)
1670 struct ctl_table *p;
1671 const char *s = branch->procname;
1673 /* branch should have named subdirectory as its first element */
1674 if (!s || !branch->child)
1677 /* ... and nothing else */
1678 if (branch[1].procname)
1681 /* table should contain subdirectory with the same name */
1682 for (p = table; p->procname; p++) {
1685 if (p->procname && strcmp(p->procname, s) == 0)
1691 /* see if attaching q to p would be an improvement */
1692 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1694 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1695 struct ctl_table *next;
1697 int not_in_parent = !p->attached_by;
1699 while ((next = is_branch_in(by, to)) != NULL) {
1700 if (by == q->attached_by)
1702 if (to == p->attached_by)
1708 if (is_better && not_in_parent) {
1709 q->attached_by = by;
1710 q->attached_to = to;
1716 * __register_sysctl_paths - register a sysctl hierarchy
1717 * @root: List of sysctl headers to register on
1718 * @namespaces: Data to compute which lists of sysctl entries are visible
1719 * @path: The path to the directory the sysctl table is in.
1720 * @table: the top-level table structure
1722 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1723 * array. A completely 0 filled entry terminates the table.
1725 * The members of the &struct ctl_table structure are used as follows:
1727 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1728 * enter a sysctl file
1730 * data - a pointer to data for use by proc_handler
1732 * maxlen - the maximum size in bytes of the data
1734 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1736 * child - a pointer to the child sysctl table if this entry is a directory, or
1739 * proc_handler - the text handler routine (described below)
1741 * de - for internal use by the sysctl routines
1743 * extra1, extra2 - extra pointers usable by the proc handler routines
1745 * Leaf nodes in the sysctl tree will be represented by a single file
1746 * under /proc; non-leaf nodes will be represented by directories.
1748 * sysctl(2) can automatically manage read and write requests through
1749 * the sysctl table. The data and maxlen fields of the ctl_table
1750 * struct enable minimal validation of the values being written to be
1751 * performed, and the mode field allows minimal authentication.
1753 * There must be a proc_handler routine for any terminal nodes
1754 * mirrored under /proc/sys (non-terminals are handled by a built-in
1755 * directory handler). Several default handlers are available to
1756 * cover common cases -
1758 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1759 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1760 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1762 * It is the handler's job to read the input buffer from user memory
1763 * and process it. The handler should return 0 on success.
1765 * This routine returns %NULL on a failure to register, and a pointer
1766 * to the table header on success.
1768 struct ctl_table_header *__register_sysctl_paths(
1769 struct ctl_table_root *root,
1770 struct nsproxy *namespaces,
1771 const struct ctl_path *path, struct ctl_table *table)
1773 struct ctl_table_header *header;
1774 struct ctl_table *new, **prevp;
1775 unsigned int n, npath;
1776 struct ctl_table_set *set;
1778 /* Count the path components */
1779 for (npath = 0; path[npath].procname; ++npath)
1783 * For each path component, allocate a 2-element ctl_table array.
1784 * The first array element will be filled with the sysctl entry
1785 * for this, the second will be the sentinel (procname == 0).
1787 * We allocate everything in one go so that we don't have to
1788 * worry about freeing additional memory in unregister_sysctl_table.
1790 header = kzalloc(sizeof(struct ctl_table_header) +
1791 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1795 new = (struct ctl_table *) (header + 1);
1797 /* Now connect the dots */
1798 prevp = &header->ctl_table;
1799 for (n = 0; n < npath; ++n, ++path) {
1800 /* Copy the procname */
1801 new->procname = path->procname;
1805 prevp = &new->child;
1810 header->ctl_table_arg = table;
1812 INIT_LIST_HEAD(&header->ctl_entry);
1814 header->unregistering = NULL;
1815 header->root = root;
1816 sysctl_set_parent(NULL, header->ctl_table);
1818 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1819 if (sysctl_check_table(namespaces, header->ctl_table)) {
1824 spin_lock(&sysctl_lock);
1825 header->set = lookup_header_set(root, namespaces);
1826 header->attached_by = header->ctl_table;
1827 header->attached_to = root_table;
1828 header->parent = &root_table_header;
1829 for (set = header->set; set; set = set->parent) {
1830 struct ctl_table_header *p;
1831 list_for_each_entry(p, &set->list, ctl_entry) {
1832 if (p->unregistering)
1834 try_attach(p, header);
1837 header->parent->count++;
1838 list_add_tail(&header->ctl_entry, &header->set->list);
1839 spin_unlock(&sysctl_lock);
1845 * register_sysctl_table_path - register a sysctl table hierarchy
1846 * @path: The path to the directory the sysctl table is in.
1847 * @table: the top-level table structure
1849 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1850 * array. A completely 0 filled entry terminates the table.
1852 * See __register_sysctl_paths for more details.
1854 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1855 struct ctl_table *table)
1857 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1862 * register_sysctl_table - register a sysctl table hierarchy
1863 * @table: the top-level table structure
1865 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1866 * array. A completely 0 filled entry terminates the table.
1868 * See register_sysctl_paths for more details.
1870 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1872 static const struct ctl_path null_path[] = { {} };
1874 return register_sysctl_paths(null_path, table);
1878 * unregister_sysctl_table - unregister a sysctl table hierarchy
1879 * @header: the header returned from register_sysctl_table
1881 * Unregisters the sysctl table and all children. proc entries may not
1882 * actually be removed until they are no longer used by anyone.
1884 void unregister_sysctl_table(struct ctl_table_header * header)
1891 spin_lock(&sysctl_lock);
1892 start_unregistering(header);
1893 if (!--header->parent->count) {
1895 kfree(header->parent);
1897 if (!--header->count)
1899 spin_unlock(&sysctl_lock);
1902 int sysctl_is_seen(struct ctl_table_header *p)
1904 struct ctl_table_set *set = p->set;
1906 spin_lock(&sysctl_lock);
1907 if (p->unregistering)
1909 else if (!set->is_seen)
1912 res = set->is_seen(set);
1913 spin_unlock(&sysctl_lock);
1917 void setup_sysctl_set(struct ctl_table_set *p,
1918 struct ctl_table_set *parent,
1919 int (*is_seen)(struct ctl_table_set *))
1921 INIT_LIST_HEAD(&p->list);
1922 p->parent = parent ? parent : &sysctl_table_root.default_set;
1923 p->is_seen = is_seen;
1926 #else /* !CONFIG_SYSCTL */
1927 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1932 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1933 struct ctl_table *table)
1938 void unregister_sysctl_table(struct ctl_table_header * table)
1942 void setup_sysctl_set(struct ctl_table_set *p,
1943 struct ctl_table_set *parent,
1944 int (*is_seen)(struct ctl_table_set *))
1948 void sysctl_head_put(struct ctl_table_header *head)
1952 #endif /* CONFIG_SYSCTL */
1958 #ifdef CONFIG_PROC_SYSCTL
1960 static int _proc_do_string(void* data, int maxlen, int write,
1961 void __user *buffer,
1962 size_t *lenp, loff_t *ppos)
1968 if (!data || !maxlen || !*lenp) {
1976 while (len < *lenp) {
1977 if (get_user(c, p++))
1979 if (c == 0 || c == '\n')
1985 if(copy_from_user(data, buffer, len))
1987 ((char *) data)[len] = 0;
2005 if(copy_to_user(buffer, data, len))
2008 if(put_user('\n', ((char __user *) buffer) + len))
2019 * proc_dostring - read a string sysctl
2020 * @table: the sysctl table
2021 * @write: %TRUE if this is a write to the sysctl file
2022 * @buffer: the user buffer
2023 * @lenp: the size of the user buffer
2024 * @ppos: file position
2026 * Reads/writes a string from/to the user buffer. If the kernel
2027 * buffer provided is not large enough to hold the string, the
2028 * string is truncated. The copied string is %NULL-terminated.
2029 * If the string is being read by the user process, it is copied
2030 * and a newline '\n' is added. It is truncated if the buffer is
2033 * Returns 0 on success.
2035 int proc_dostring(struct ctl_table *table, int write,
2036 void __user *buffer, size_t *lenp, loff_t *ppos)
2038 return _proc_do_string(table->data, table->maxlen, write,
2039 buffer, lenp, ppos);
2043 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2045 int write, void *data)
2048 *valp = *negp ? -*lvalp : *lvalp;
2053 *lvalp = (unsigned long)-val;
2056 *lvalp = (unsigned long)val;
2062 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2063 int write, void __user *buffer,
2064 size_t *lenp, loff_t *ppos,
2065 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2066 int write, void *data),
2069 #define TMPBUFLEN 21
2070 int *i, vleft, first = 1, neg;
2074 char buf[TMPBUFLEN], *p;
2075 char __user *s = buffer;
2077 if (!tbl_data || !table->maxlen || !*lenp ||
2078 (*ppos && !write)) {
2083 i = (int *) tbl_data;
2084 vleft = table->maxlen / sizeof(*i);
2088 conv = do_proc_dointvec_conv;
2090 for (; left && vleft--; i++, first=0) {
2105 if (len > sizeof(buf) - 1)
2106 len = sizeof(buf) - 1;
2107 if (copy_from_user(buf, s, len))
2111 if (*p == '-' && left > 1) {
2115 if (*p < '0' || *p > '9')
2118 lval = simple_strtoul(p, &p, 0);
2121 if ((len < left) && *p && !isspace(*p))
2126 if (conv(&neg, &lval, i, 1, data))
2133 if (conv(&neg, &lval, i, 0, data))
2136 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2140 if(copy_to_user(s, buf, len))
2147 if (!write && !first && left) {
2148 if(put_user('\n', s))
2155 if (get_user(c, s++))
2170 static int do_proc_dointvec(struct ctl_table *table, int write,
2171 void __user *buffer, size_t *lenp, loff_t *ppos,
2172 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2173 int write, void *data),
2176 return __do_proc_dointvec(table->data, table, write,
2177 buffer, lenp, ppos, conv, data);
2181 * proc_dointvec - read a vector of integers
2182 * @table: the sysctl table
2183 * @write: %TRUE if this is a write to the sysctl file
2184 * @buffer: the user buffer
2185 * @lenp: the size of the user buffer
2186 * @ppos: file position
2188 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2189 * values from/to the user buffer, treated as an ASCII string.
2191 * Returns 0 on success.
2193 int proc_dointvec(struct ctl_table *table, int write,
2194 void __user *buffer, size_t *lenp, loff_t *ppos)
2196 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2201 * Taint values can only be increased
2202 * This means we can safely use a temporary.
2204 static int proc_taint(struct ctl_table *table, int write,
2205 void __user *buffer, size_t *lenp, loff_t *ppos)
2208 unsigned long tmptaint = get_taint();
2211 if (write && !capable(CAP_SYS_ADMIN))
2216 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2222 * Poor man's atomic or. Not worth adding a primitive
2223 * to everyone's atomic.h for this
2226 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2227 if ((tmptaint >> i) & 1)
2235 struct do_proc_dointvec_minmax_conv_param {
2240 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2242 int write, void *data)
2244 struct do_proc_dointvec_minmax_conv_param *param = data;
2246 int val = *negp ? -*lvalp : *lvalp;
2247 if ((param->min && *param->min > val) ||
2248 (param->max && *param->max < val))
2255 *lvalp = (unsigned long)-val;
2258 *lvalp = (unsigned long)val;
2265 * proc_dointvec_minmax - read a vector of integers with min/max values
2266 * @table: the sysctl table
2267 * @write: %TRUE if this is a write to the sysctl file
2268 * @buffer: the user buffer
2269 * @lenp: the size of the user buffer
2270 * @ppos: file position
2272 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2273 * values from/to the user buffer, treated as an ASCII string.
2275 * This routine will ensure the values are within the range specified by
2276 * table->extra1 (min) and table->extra2 (max).
2278 * Returns 0 on success.
2280 int proc_dointvec_minmax(struct ctl_table *table, int write,
2281 void __user *buffer, size_t *lenp, loff_t *ppos)
2283 struct do_proc_dointvec_minmax_conv_param param = {
2284 .min = (int *) table->extra1,
2285 .max = (int *) table->extra2,
2287 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2288 do_proc_dointvec_minmax_conv, ¶m);
2291 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2292 void __user *buffer,
2293 size_t *lenp, loff_t *ppos,
2294 unsigned long convmul,
2295 unsigned long convdiv)
2297 #define TMPBUFLEN 21
2298 unsigned long *i, *min, *max, val;
2299 int vleft, first=1, neg;
2301 char buf[TMPBUFLEN], *p;
2302 char __user *s = buffer;
2304 if (!data || !table->maxlen || !*lenp ||
2305 (*ppos && !write)) {
2310 i = (unsigned long *) data;
2311 min = (unsigned long *) table->extra1;
2312 max = (unsigned long *) table->extra2;
2313 vleft = table->maxlen / sizeof(unsigned long);
2316 for (; left && vleft--; i++, min++, max++, first=0) {
2331 if (len > TMPBUFLEN-1)
2333 if (copy_from_user(buf, s, len))
2337 if (*p == '-' && left > 1) {
2341 if (*p < '0' || *p > '9')
2343 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2345 if ((len < left) && *p && !isspace(*p))
2354 if ((min && val < *min) || (max && val > *max))
2361 sprintf(p, "%lu", convdiv * (*i) / convmul);
2365 if(copy_to_user(s, buf, len))
2372 if (!write && !first && left) {
2373 if(put_user('\n', s))
2380 if (get_user(c, s++))
2395 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2396 void __user *buffer,
2397 size_t *lenp, loff_t *ppos,
2398 unsigned long convmul,
2399 unsigned long convdiv)
2401 return __do_proc_doulongvec_minmax(table->data, table, write,
2402 buffer, lenp, ppos, convmul, convdiv);
2406 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2407 * @table: the sysctl table
2408 * @write: %TRUE if this is a write to the sysctl file
2409 * @buffer: the user buffer
2410 * @lenp: the size of the user buffer
2411 * @ppos: file position
2413 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2414 * values from/to the user buffer, treated as an ASCII string.
2416 * This routine will ensure the values are within the range specified by
2417 * table->extra1 (min) and table->extra2 (max).
2419 * Returns 0 on success.
2421 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2422 void __user *buffer, size_t *lenp, loff_t *ppos)
2424 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2428 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2429 * @table: the sysctl table
2430 * @write: %TRUE if this is a write to the sysctl file
2431 * @buffer: the user buffer
2432 * @lenp: the size of the user buffer
2433 * @ppos: file position
2435 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2436 * values from/to the user buffer, treated as an ASCII string. The values
2437 * are treated as milliseconds, and converted to jiffies when they are stored.
2439 * This routine will ensure the values are within the range specified by
2440 * table->extra1 (min) and table->extra2 (max).
2442 * Returns 0 on success.
2444 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2445 void __user *buffer,
2446 size_t *lenp, loff_t *ppos)
2448 return do_proc_doulongvec_minmax(table, write, buffer,
2449 lenp, ppos, HZ, 1000l);
2453 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2455 int write, void *data)
2458 if (*lvalp > LONG_MAX / HZ)
2460 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2466 lval = (unsigned long)-val;
2469 lval = (unsigned long)val;
2476 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2478 int write, void *data)
2481 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2483 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2489 lval = (unsigned long)-val;
2492 lval = (unsigned long)val;
2494 *lvalp = jiffies_to_clock_t(lval);
2499 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2501 int write, void *data)
2504 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2510 lval = (unsigned long)-val;
2513 lval = (unsigned long)val;
2515 *lvalp = jiffies_to_msecs(lval);
2521 * proc_dointvec_jiffies - read a vector of integers as seconds
2522 * @table: the sysctl table
2523 * @write: %TRUE if this is a write to the sysctl file
2524 * @buffer: the user buffer
2525 * @lenp: the size of the user buffer
2526 * @ppos: file position
2528 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2529 * values from/to the user buffer, treated as an ASCII string.
2530 * The values read are assumed to be in seconds, and are converted into
2533 * Returns 0 on success.
2535 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2536 void __user *buffer, size_t *lenp, loff_t *ppos)
2538 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2539 do_proc_dointvec_jiffies_conv,NULL);
2543 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2544 * @table: the sysctl table
2545 * @write: %TRUE if this is a write to the sysctl file
2546 * @buffer: the user buffer
2547 * @lenp: the size of the user buffer
2548 * @ppos: pointer to the file position
2550 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2551 * values from/to the user buffer, treated as an ASCII string.
2552 * The values read are assumed to be in 1/USER_HZ seconds, and
2553 * are converted into jiffies.
2555 * Returns 0 on success.
2557 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2558 void __user *buffer, size_t *lenp, loff_t *ppos)
2560 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2561 do_proc_dointvec_userhz_jiffies_conv,NULL);
2565 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2566 * @table: the sysctl table
2567 * @write: %TRUE if this is a write to the sysctl file
2568 * @buffer: the user buffer
2569 * @lenp: the size of the user buffer
2570 * @ppos: file position
2571 * @ppos: the current position in the file
2573 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2574 * values from/to the user buffer, treated as an ASCII string.
2575 * The values read are assumed to be in 1/1000 seconds, and
2576 * are converted into jiffies.
2578 * Returns 0 on success.
2580 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2581 void __user *buffer, size_t *lenp, loff_t *ppos)
2583 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2584 do_proc_dointvec_ms_jiffies_conv, NULL);
2587 static int proc_do_cad_pid(struct ctl_table *table, int write,
2588 void __user *buffer, size_t *lenp, loff_t *ppos)
2590 struct pid *new_pid;
2594 tmp = pid_vnr(cad_pid);
2596 r = __do_proc_dointvec(&tmp, table, write, buffer,
2597 lenp, ppos, NULL, NULL);
2601 new_pid = find_get_pid(tmp);
2605 put_pid(xchg(&cad_pid, new_pid));
2609 #else /* CONFIG_PROC_FS */
2611 int proc_dostring(struct ctl_table *table, int write,
2612 void __user *buffer, size_t *lenp, loff_t *ppos)
2617 int proc_dointvec(struct ctl_table *table, int write,
2618 void __user *buffer, size_t *lenp, loff_t *ppos)
2623 int proc_dointvec_minmax(struct ctl_table *table, int write,
2624 void __user *buffer, size_t *lenp, loff_t *ppos)
2629 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2630 void __user *buffer, size_t *lenp, loff_t *ppos)
2635 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2636 void __user *buffer, size_t *lenp, loff_t *ppos)
2641 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2642 void __user *buffer, size_t *lenp, loff_t *ppos)
2647 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2648 void __user *buffer, size_t *lenp, loff_t *ppos)
2653 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2654 void __user *buffer,
2655 size_t *lenp, loff_t *ppos)
2661 #endif /* CONFIG_PROC_FS */
2664 * No sense putting this after each symbol definition, twice,
2665 * exception granted :-)
2667 EXPORT_SYMBOL(proc_dointvec);
2668 EXPORT_SYMBOL(proc_dointvec_jiffies);
2669 EXPORT_SYMBOL(proc_dointvec_minmax);
2670 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2671 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2672 EXPORT_SYMBOL(proc_dostring);
2673 EXPORT_SYMBOL(proc_doulongvec_minmax);
2674 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2675 EXPORT_SYMBOL(register_sysctl_table);
2676 EXPORT_SYMBOL(register_sysctl_paths);
2677 EXPORT_SYMBOL(unregister_sysctl_table);