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>
30 #include <linux/smp_lock.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>
55 #include <asm/uaccess.h>
56 #include <asm/processor.h>
60 #include <asm/stacktrace.h>
64 static int deprecated_sysctl_warning(struct __sysctl_args *args);
66 #if defined(CONFIG_SYSCTL)
68 /* External variables not in a header file. */
70 extern int print_fatal_signals;
71 extern int sysctl_overcommit_memory;
72 extern int sysctl_overcommit_ratio;
73 extern int sysctl_panic_on_oom;
74 extern int sysctl_oom_kill_allocating_task;
75 extern int sysctl_oom_dump_tasks;
76 extern int max_threads;
77 extern int core_uses_pid;
78 extern int suid_dumpable;
79 extern char core_pattern[];
80 extern unsigned int core_pipe_limit;
82 extern int min_free_kbytes;
83 extern int pid_max_min, pid_max_max;
84 extern int sysctl_drop_caches;
85 extern int percpu_pagelist_fraction;
86 extern int compat_log;
87 extern int latencytop_enabled;
88 extern int sysctl_nr_open_min, sysctl_nr_open_max;
90 extern int sysctl_nr_trim_pages;
92 #ifdef CONFIG_RCU_TORTURE_TEST
93 extern int rcutorture_runnable;
94 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
96 extern int blk_iopoll_enabled;
99 /* Constants used for minimum and maximum */
100 #ifdef CONFIG_DETECT_SOFTLOCKUP
101 static int sixty = 60;
102 static int neg_one = -1;
106 static int __maybe_unused one = 1;
107 static int __maybe_unused two = 2;
108 static unsigned long one_ul = 1;
109 static int one_hundred = 100;
111 static int ten_thousand = 10000;
114 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
115 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
117 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
118 static int maxolduid = 65535;
119 static int minolduid;
120 static int min_percpu_pagelist_fract = 8;
122 static int ngroups_max = NGROUPS_MAX;
124 #ifdef CONFIG_MODULES
125 extern char modprobe_path[];
126 extern int modules_disabled;
128 #ifdef CONFIG_CHR_DEV_SG
129 extern int sg_big_buff;
133 #include <asm/system.h>
136 #ifdef CONFIG_SPARC64
137 extern int sysctl_tsb_ratio;
141 extern int pwrsw_enabled;
142 extern int unaligned_enabled;
146 #ifdef CONFIG_MATHEMU
147 extern int sysctl_ieee_emulation_warnings;
149 extern int sysctl_userprocess_debug;
150 extern int spin_retry;
153 #ifdef CONFIG_BSD_PROCESS_ACCT
154 extern int acct_parm[];
158 extern int no_unaligned_warning;
159 extern int unaligned_dump_stack;
162 extern struct ratelimit_state printk_ratelimit_state;
164 #ifdef CONFIG_RT_MUTEXES
165 extern int max_lock_depth;
168 #ifdef CONFIG_PROC_SYSCTL
169 static int proc_do_cad_pid(struct ctl_table *table, int write,
170 void __user *buffer, size_t *lenp, loff_t *ppos);
171 static int proc_taint(struct ctl_table *table, int write,
172 void __user *buffer, size_t *lenp, loff_t *ppos);
175 static struct ctl_table root_table[];
176 static struct ctl_table_root sysctl_table_root;
177 static struct ctl_table_header root_table_header = {
179 .ctl_table = root_table,
180 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
181 .root = &sysctl_table_root,
182 .set = &sysctl_table_root.default_set,
184 static struct ctl_table_root sysctl_table_root = {
185 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
186 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
189 static struct ctl_table kern_table[];
190 static struct ctl_table vm_table[];
191 static struct ctl_table fs_table[];
192 static struct ctl_table debug_table[];
193 static struct ctl_table dev_table[];
194 extern struct ctl_table random_table[];
195 #ifdef CONFIG_INOTIFY_USER
196 extern struct ctl_table inotify_table[];
199 extern struct ctl_table epoll_table[];
202 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
203 int sysctl_legacy_va_layout;
206 extern int prove_locking;
207 extern int lock_stat;
209 /* The default sysctl tables: */
211 static struct ctl_table root_table[] = {
213 .ctl_name = CTL_KERN,
214 .procname = "kernel",
231 .ctl_name = CTL_DEBUG,
234 .child = debug_table,
243 * NOTE: do not add new entries to this table unless you have read
244 * Documentation/sysctl/ctl_unnumbered.txt
249 #ifdef CONFIG_SCHED_DEBUG
250 static int min_sched_granularity_ns = 100000; /* 100 usecs */
251 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
252 static int min_wakeup_granularity_ns; /* 0 usecs */
253 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
256 static struct ctl_table kern_table[] = {
258 .ctl_name = CTL_UNNUMBERED,
259 .procname = "sched_child_runs_first",
260 .data = &sysctl_sched_child_runs_first,
261 .maxlen = sizeof(unsigned int),
263 .proc_handler = &proc_dointvec,
265 #ifdef CONFIG_SCHED_DEBUG
267 .ctl_name = CTL_UNNUMBERED,
268 .procname = "sched_min_granularity_ns",
269 .data = &sysctl_sched_min_granularity,
270 .maxlen = sizeof(unsigned int),
272 .proc_handler = &sched_nr_latency_handler,
273 .strategy = &sysctl_intvec,
274 .extra1 = &min_sched_granularity_ns,
275 .extra2 = &max_sched_granularity_ns,
278 .ctl_name = CTL_UNNUMBERED,
279 .procname = "sched_latency_ns",
280 .data = &sysctl_sched_latency,
281 .maxlen = sizeof(unsigned int),
283 .proc_handler = &sched_nr_latency_handler,
284 .strategy = &sysctl_intvec,
285 .extra1 = &min_sched_granularity_ns,
286 .extra2 = &max_sched_granularity_ns,
289 .ctl_name = CTL_UNNUMBERED,
290 .procname = "sched_wakeup_granularity_ns",
291 .data = &sysctl_sched_wakeup_granularity,
292 .maxlen = sizeof(unsigned int),
294 .proc_handler = &proc_dointvec_minmax,
295 .strategy = &sysctl_intvec,
296 .extra1 = &min_wakeup_granularity_ns,
297 .extra2 = &max_wakeup_granularity_ns,
300 .ctl_name = CTL_UNNUMBERED,
301 .procname = "sched_shares_ratelimit",
302 .data = &sysctl_sched_shares_ratelimit,
303 .maxlen = sizeof(unsigned int),
305 .proc_handler = &proc_dointvec,
308 .ctl_name = CTL_UNNUMBERED,
309 .procname = "sched_shares_thresh",
310 .data = &sysctl_sched_shares_thresh,
311 .maxlen = sizeof(unsigned int),
313 .proc_handler = &proc_dointvec_minmax,
314 .strategy = &sysctl_intvec,
318 .ctl_name = CTL_UNNUMBERED,
319 .procname = "sched_features",
320 .data = &sysctl_sched_features,
321 .maxlen = sizeof(unsigned int),
323 .proc_handler = &proc_dointvec,
326 .ctl_name = CTL_UNNUMBERED,
327 .procname = "sched_migration_cost",
328 .data = &sysctl_sched_migration_cost,
329 .maxlen = sizeof(unsigned int),
331 .proc_handler = &proc_dointvec,
334 .ctl_name = CTL_UNNUMBERED,
335 .procname = "sched_nr_migrate",
336 .data = &sysctl_sched_nr_migrate,
337 .maxlen = sizeof(unsigned int),
339 .proc_handler = &proc_dointvec,
342 .ctl_name = CTL_UNNUMBERED,
343 .procname = "sched_time_avg",
344 .data = &sysctl_sched_time_avg,
345 .maxlen = sizeof(unsigned int),
347 .proc_handler = &proc_dointvec,
350 .ctl_name = CTL_UNNUMBERED,
351 .procname = "timer_migration",
352 .data = &sysctl_timer_migration,
353 .maxlen = sizeof(unsigned int),
355 .proc_handler = &proc_dointvec_minmax,
356 .strategy = &sysctl_intvec,
362 .ctl_name = CTL_UNNUMBERED,
363 .procname = "sched_rt_period_us",
364 .data = &sysctl_sched_rt_period,
365 .maxlen = sizeof(unsigned int),
367 .proc_handler = &sched_rt_handler,
370 .ctl_name = CTL_UNNUMBERED,
371 .procname = "sched_rt_runtime_us",
372 .data = &sysctl_sched_rt_runtime,
373 .maxlen = sizeof(int),
375 .proc_handler = &sched_rt_handler,
378 .ctl_name = CTL_UNNUMBERED,
379 .procname = "sched_compat_yield",
380 .data = &sysctl_sched_compat_yield,
381 .maxlen = sizeof(unsigned int),
383 .proc_handler = &proc_dointvec,
385 #ifdef CONFIG_PROVE_LOCKING
387 .ctl_name = CTL_UNNUMBERED,
388 .procname = "prove_locking",
389 .data = &prove_locking,
390 .maxlen = sizeof(int),
392 .proc_handler = &proc_dointvec,
395 #ifdef CONFIG_LOCK_STAT
397 .ctl_name = CTL_UNNUMBERED,
398 .procname = "lock_stat",
400 .maxlen = sizeof(int),
402 .proc_handler = &proc_dointvec,
406 .ctl_name = KERN_PANIC,
408 .data = &panic_timeout,
409 .maxlen = sizeof(int),
411 .proc_handler = &proc_dointvec,
414 .ctl_name = KERN_CORE_USES_PID,
415 .procname = "core_uses_pid",
416 .data = &core_uses_pid,
417 .maxlen = sizeof(int),
419 .proc_handler = &proc_dointvec,
422 .ctl_name = KERN_CORE_PATTERN,
423 .procname = "core_pattern",
424 .data = core_pattern,
425 .maxlen = CORENAME_MAX_SIZE,
427 .proc_handler = &proc_dostring,
428 .strategy = &sysctl_string,
431 .ctl_name = CTL_UNNUMBERED,
432 .procname = "core_pipe_limit",
433 .data = &core_pipe_limit,
434 .maxlen = sizeof(unsigned int),
436 .proc_handler = &proc_dointvec,
438 #ifdef CONFIG_PROC_SYSCTL
440 .procname = "tainted",
441 .maxlen = sizeof(long),
443 .proc_handler = &proc_taint,
446 #ifdef CONFIG_LATENCYTOP
448 .procname = "latencytop",
449 .data = &latencytop_enabled,
450 .maxlen = sizeof(int),
452 .proc_handler = &proc_dointvec,
455 #ifdef CONFIG_BLK_DEV_INITRD
457 .ctl_name = KERN_REALROOTDEV,
458 .procname = "real-root-dev",
459 .data = &real_root_dev,
460 .maxlen = sizeof(int),
462 .proc_handler = &proc_dointvec,
466 .ctl_name = CTL_UNNUMBERED,
467 .procname = "print-fatal-signals",
468 .data = &print_fatal_signals,
469 .maxlen = sizeof(int),
471 .proc_handler = &proc_dointvec,
475 .ctl_name = KERN_SPARC_REBOOT,
476 .procname = "reboot-cmd",
477 .data = reboot_command,
480 .proc_handler = &proc_dostring,
481 .strategy = &sysctl_string,
484 .ctl_name = KERN_SPARC_STOP_A,
485 .procname = "stop-a",
486 .data = &stop_a_enabled,
487 .maxlen = sizeof (int),
489 .proc_handler = &proc_dointvec,
492 .ctl_name = KERN_SPARC_SCONS_PWROFF,
493 .procname = "scons-poweroff",
494 .data = &scons_pwroff,
495 .maxlen = sizeof (int),
497 .proc_handler = &proc_dointvec,
500 #ifdef CONFIG_SPARC64
502 .ctl_name = CTL_UNNUMBERED,
503 .procname = "tsb-ratio",
504 .data = &sysctl_tsb_ratio,
505 .maxlen = sizeof (int),
507 .proc_handler = &proc_dointvec,
512 .ctl_name = KERN_HPPA_PWRSW,
513 .procname = "soft-power",
514 .data = &pwrsw_enabled,
515 .maxlen = sizeof (int),
517 .proc_handler = &proc_dointvec,
520 .ctl_name = KERN_HPPA_UNALIGNED,
521 .procname = "unaligned-trap",
522 .data = &unaligned_enabled,
523 .maxlen = sizeof (int),
525 .proc_handler = &proc_dointvec,
529 .ctl_name = KERN_CTLALTDEL,
530 .procname = "ctrl-alt-del",
532 .maxlen = sizeof(int),
534 .proc_handler = &proc_dointvec,
536 #ifdef CONFIG_FUNCTION_TRACER
538 .ctl_name = CTL_UNNUMBERED,
539 .procname = "ftrace_enabled",
540 .data = &ftrace_enabled,
541 .maxlen = sizeof(int),
543 .proc_handler = &ftrace_enable_sysctl,
546 #ifdef CONFIG_STACK_TRACER
548 .ctl_name = CTL_UNNUMBERED,
549 .procname = "stack_tracer_enabled",
550 .data = &stack_tracer_enabled,
551 .maxlen = sizeof(int),
553 .proc_handler = &stack_trace_sysctl,
556 #ifdef CONFIG_TRACING
558 .ctl_name = CTL_UNNUMBERED,
559 .procname = "ftrace_dump_on_oops",
560 .data = &ftrace_dump_on_oops,
561 .maxlen = sizeof(int),
563 .proc_handler = &proc_dointvec,
566 #ifdef CONFIG_MODULES
568 .ctl_name = KERN_MODPROBE,
569 .procname = "modprobe",
570 .data = &modprobe_path,
571 .maxlen = KMOD_PATH_LEN,
573 .proc_handler = &proc_dostring,
574 .strategy = &sysctl_string,
577 .ctl_name = CTL_UNNUMBERED,
578 .procname = "modules_disabled",
579 .data = &modules_disabled,
580 .maxlen = sizeof(int),
582 /* only handle a transition from default "0" to "1" */
583 .proc_handler = &proc_dointvec_minmax,
588 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
590 .ctl_name = KERN_HOTPLUG,
591 .procname = "hotplug",
592 .data = &uevent_helper,
593 .maxlen = UEVENT_HELPER_PATH_LEN,
595 .proc_handler = &proc_dostring,
596 .strategy = &sysctl_string,
599 #ifdef CONFIG_CHR_DEV_SG
601 .ctl_name = KERN_SG_BIG_BUFF,
602 .procname = "sg-big-buff",
603 .data = &sg_big_buff,
604 .maxlen = sizeof (int),
606 .proc_handler = &proc_dointvec,
609 #ifdef CONFIG_BSD_PROCESS_ACCT
611 .ctl_name = KERN_ACCT,
614 .maxlen = 3*sizeof(int),
616 .proc_handler = &proc_dointvec,
619 #ifdef CONFIG_MAGIC_SYSRQ
621 .ctl_name = KERN_SYSRQ,
623 .data = &__sysrq_enabled,
624 .maxlen = sizeof (int),
626 .proc_handler = &proc_dointvec,
629 #ifdef CONFIG_PROC_SYSCTL
631 .procname = "cad_pid",
633 .maxlen = sizeof (int),
635 .proc_handler = &proc_do_cad_pid,
639 .ctl_name = KERN_MAX_THREADS,
640 .procname = "threads-max",
641 .data = &max_threads,
642 .maxlen = sizeof(int),
644 .proc_handler = &proc_dointvec,
647 .ctl_name = KERN_RANDOM,
648 .procname = "random",
650 .child = random_table,
653 .ctl_name = KERN_OVERFLOWUID,
654 .procname = "overflowuid",
655 .data = &overflowuid,
656 .maxlen = sizeof(int),
658 .proc_handler = &proc_dointvec_minmax,
659 .strategy = &sysctl_intvec,
660 .extra1 = &minolduid,
661 .extra2 = &maxolduid,
664 .ctl_name = KERN_OVERFLOWGID,
665 .procname = "overflowgid",
666 .data = &overflowgid,
667 .maxlen = sizeof(int),
669 .proc_handler = &proc_dointvec_minmax,
670 .strategy = &sysctl_intvec,
671 .extra1 = &minolduid,
672 .extra2 = &maxolduid,
675 #ifdef CONFIG_MATHEMU
677 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
678 .procname = "ieee_emulation_warnings",
679 .data = &sysctl_ieee_emulation_warnings,
680 .maxlen = sizeof(int),
682 .proc_handler = &proc_dointvec,
686 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
687 .procname = "userprocess_debug",
688 .data = &sysctl_userprocess_debug,
689 .maxlen = sizeof(int),
691 .proc_handler = &proc_dointvec,
695 .ctl_name = KERN_PIDMAX,
696 .procname = "pid_max",
698 .maxlen = sizeof (int),
700 .proc_handler = &proc_dointvec_minmax,
701 .strategy = sysctl_intvec,
702 .extra1 = &pid_max_min,
703 .extra2 = &pid_max_max,
706 .ctl_name = KERN_PANIC_ON_OOPS,
707 .procname = "panic_on_oops",
708 .data = &panic_on_oops,
709 .maxlen = sizeof(int),
711 .proc_handler = &proc_dointvec,
713 #if defined CONFIG_PRINTK
715 .ctl_name = KERN_PRINTK,
716 .procname = "printk",
717 .data = &console_loglevel,
718 .maxlen = 4*sizeof(int),
720 .proc_handler = &proc_dointvec,
723 .ctl_name = KERN_PRINTK_RATELIMIT,
724 .procname = "printk_ratelimit",
725 .data = &printk_ratelimit_state.interval,
726 .maxlen = sizeof(int),
728 .proc_handler = &proc_dointvec_jiffies,
729 .strategy = &sysctl_jiffies,
732 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
733 .procname = "printk_ratelimit_burst",
734 .data = &printk_ratelimit_state.burst,
735 .maxlen = sizeof(int),
737 .proc_handler = &proc_dointvec,
740 .ctl_name = CTL_UNNUMBERED,
741 .procname = "printk_delay",
742 .data = &printk_delay_msec,
743 .maxlen = sizeof(int),
745 .proc_handler = &proc_dointvec_minmax,
746 .strategy = &sysctl_intvec,
748 .extra2 = &ten_thousand,
752 .ctl_name = KERN_NGROUPS_MAX,
753 .procname = "ngroups_max",
754 .data = &ngroups_max,
755 .maxlen = sizeof (int),
757 .proc_handler = &proc_dointvec,
759 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
761 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
762 .procname = "unknown_nmi_panic",
763 .data = &unknown_nmi_panic,
764 .maxlen = sizeof (int),
766 .proc_handler = &proc_dointvec,
769 .procname = "nmi_watchdog",
770 .data = &nmi_watchdog_enabled,
771 .maxlen = sizeof (int),
773 .proc_handler = &proc_nmi_enabled,
776 #if defined(CONFIG_X86)
778 .ctl_name = KERN_PANIC_ON_NMI,
779 .procname = "panic_on_unrecovered_nmi",
780 .data = &panic_on_unrecovered_nmi,
781 .maxlen = sizeof(int),
783 .proc_handler = &proc_dointvec,
786 .ctl_name = CTL_UNNUMBERED,
787 .procname = "panic_on_io_nmi",
788 .data = &panic_on_io_nmi,
789 .maxlen = sizeof(int),
791 .proc_handler = &proc_dointvec,
794 .ctl_name = KERN_BOOTLOADER_TYPE,
795 .procname = "bootloader_type",
796 .data = &bootloader_type,
797 .maxlen = sizeof (int),
799 .proc_handler = &proc_dointvec,
802 .ctl_name = CTL_UNNUMBERED,
803 .procname = "bootloader_version",
804 .data = &bootloader_version,
805 .maxlen = sizeof (int),
807 .proc_handler = &proc_dointvec,
810 .ctl_name = CTL_UNNUMBERED,
811 .procname = "kstack_depth_to_print",
812 .data = &kstack_depth_to_print,
813 .maxlen = sizeof(int),
815 .proc_handler = &proc_dointvec,
818 .ctl_name = CTL_UNNUMBERED,
819 .procname = "io_delay_type",
820 .data = &io_delay_type,
821 .maxlen = sizeof(int),
823 .proc_handler = &proc_dointvec,
826 #if defined(CONFIG_MMU)
828 .ctl_name = KERN_RANDOMIZE,
829 .procname = "randomize_va_space",
830 .data = &randomize_va_space,
831 .maxlen = sizeof(int),
833 .proc_handler = &proc_dointvec,
836 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
838 .ctl_name = KERN_SPIN_RETRY,
839 .procname = "spin_retry",
841 .maxlen = sizeof (int),
843 .proc_handler = &proc_dointvec,
846 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
848 .procname = "acpi_video_flags",
849 .data = &acpi_realmode_flags,
850 .maxlen = sizeof (unsigned long),
852 .proc_handler = &proc_doulongvec_minmax,
857 .ctl_name = KERN_IA64_UNALIGNED,
858 .procname = "ignore-unaligned-usertrap",
859 .data = &no_unaligned_warning,
860 .maxlen = sizeof (int),
862 .proc_handler = &proc_dointvec,
865 .ctl_name = CTL_UNNUMBERED,
866 .procname = "unaligned-dump-stack",
867 .data = &unaligned_dump_stack,
868 .maxlen = sizeof (int),
870 .proc_handler = &proc_dointvec,
873 #ifdef CONFIG_DETECT_SOFTLOCKUP
875 .ctl_name = CTL_UNNUMBERED,
876 .procname = "softlockup_panic",
877 .data = &softlockup_panic,
878 .maxlen = sizeof(int),
880 .proc_handler = &proc_dointvec_minmax,
881 .strategy = &sysctl_intvec,
886 .ctl_name = CTL_UNNUMBERED,
887 .procname = "softlockup_thresh",
888 .data = &softlockup_thresh,
889 .maxlen = sizeof(int),
891 .proc_handler = &proc_dosoftlockup_thresh,
892 .strategy = &sysctl_intvec,
897 #ifdef CONFIG_DETECT_HUNG_TASK
899 .ctl_name = CTL_UNNUMBERED,
900 .procname = "hung_task_panic",
901 .data = &sysctl_hung_task_panic,
902 .maxlen = sizeof(int),
904 .proc_handler = &proc_dointvec_minmax,
905 .strategy = &sysctl_intvec,
910 .ctl_name = CTL_UNNUMBERED,
911 .procname = "hung_task_check_count",
912 .data = &sysctl_hung_task_check_count,
913 .maxlen = sizeof(unsigned long),
915 .proc_handler = &proc_doulongvec_minmax,
916 .strategy = &sysctl_intvec,
919 .ctl_name = CTL_UNNUMBERED,
920 .procname = "hung_task_timeout_secs",
921 .data = &sysctl_hung_task_timeout_secs,
922 .maxlen = sizeof(unsigned long),
924 .proc_handler = &proc_dohung_task_timeout_secs,
925 .strategy = &sysctl_intvec,
928 .ctl_name = CTL_UNNUMBERED,
929 .procname = "hung_task_warnings",
930 .data = &sysctl_hung_task_warnings,
931 .maxlen = sizeof(unsigned long),
933 .proc_handler = &proc_doulongvec_minmax,
934 .strategy = &sysctl_intvec,
939 .ctl_name = KERN_COMPAT_LOG,
940 .procname = "compat-log",
942 .maxlen = sizeof (int),
944 .proc_handler = &proc_dointvec,
947 #ifdef CONFIG_RT_MUTEXES
949 .ctl_name = KERN_MAX_LOCK_DEPTH,
950 .procname = "max_lock_depth",
951 .data = &max_lock_depth,
952 .maxlen = sizeof(int),
954 .proc_handler = &proc_dointvec,
958 .ctl_name = CTL_UNNUMBERED,
959 .procname = "poweroff_cmd",
960 .data = &poweroff_cmd,
961 .maxlen = POWEROFF_CMD_PATH_LEN,
963 .proc_handler = &proc_dostring,
964 .strategy = &sysctl_string,
968 .ctl_name = CTL_UNNUMBERED,
971 .child = key_sysctls,
974 #ifdef CONFIG_RCU_TORTURE_TEST
976 .ctl_name = CTL_UNNUMBERED,
977 .procname = "rcutorture_runnable",
978 .data = &rcutorture_runnable,
979 .maxlen = sizeof(int),
981 .proc_handler = &proc_dointvec,
984 #ifdef CONFIG_SLOW_WORK
986 .ctl_name = CTL_UNNUMBERED,
987 .procname = "slow-work",
989 .child = slow_work_sysctls,
992 #ifdef CONFIG_PERF_EVENTS
994 .ctl_name = CTL_UNNUMBERED,
995 .procname = "perf_event_paranoid",
996 .data = &sysctl_perf_event_paranoid,
997 .maxlen = sizeof(sysctl_perf_event_paranoid),
999 .proc_handler = &proc_dointvec,
1002 .ctl_name = CTL_UNNUMBERED,
1003 .procname = "perf_event_mlock_kb",
1004 .data = &sysctl_perf_event_mlock,
1005 .maxlen = sizeof(sysctl_perf_event_mlock),
1007 .proc_handler = &proc_dointvec,
1010 .ctl_name = CTL_UNNUMBERED,
1011 .procname = "perf_event_max_sample_rate",
1012 .data = &sysctl_perf_event_sample_rate,
1013 .maxlen = sizeof(sysctl_perf_event_sample_rate),
1015 .proc_handler = &proc_dointvec,
1018 #ifdef CONFIG_KMEMCHECK
1020 .ctl_name = CTL_UNNUMBERED,
1021 .procname = "kmemcheck",
1022 .data = &kmemcheck_enabled,
1023 .maxlen = sizeof(int),
1025 .proc_handler = &proc_dointvec,
1030 .ctl_name = CTL_UNNUMBERED,
1031 .procname = "blk_iopoll",
1032 .data = &blk_iopoll_enabled,
1033 .maxlen = sizeof(int),
1035 .proc_handler = &proc_dointvec,
1039 * NOTE: do not add new entries to this table unless you have read
1040 * Documentation/sysctl/ctl_unnumbered.txt
1045 static struct ctl_table vm_table[] = {
1047 .ctl_name = VM_OVERCOMMIT_MEMORY,
1048 .procname = "overcommit_memory",
1049 .data = &sysctl_overcommit_memory,
1050 .maxlen = sizeof(sysctl_overcommit_memory),
1052 .proc_handler = &proc_dointvec,
1055 .ctl_name = VM_PANIC_ON_OOM,
1056 .procname = "panic_on_oom",
1057 .data = &sysctl_panic_on_oom,
1058 .maxlen = sizeof(sysctl_panic_on_oom),
1060 .proc_handler = &proc_dointvec,
1063 .ctl_name = CTL_UNNUMBERED,
1064 .procname = "oom_kill_allocating_task",
1065 .data = &sysctl_oom_kill_allocating_task,
1066 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1068 .proc_handler = &proc_dointvec,
1071 .ctl_name = CTL_UNNUMBERED,
1072 .procname = "oom_dump_tasks",
1073 .data = &sysctl_oom_dump_tasks,
1074 .maxlen = sizeof(sysctl_oom_dump_tasks),
1076 .proc_handler = &proc_dointvec,
1079 .ctl_name = VM_OVERCOMMIT_RATIO,
1080 .procname = "overcommit_ratio",
1081 .data = &sysctl_overcommit_ratio,
1082 .maxlen = sizeof(sysctl_overcommit_ratio),
1084 .proc_handler = &proc_dointvec,
1087 .ctl_name = VM_PAGE_CLUSTER,
1088 .procname = "page-cluster",
1089 .data = &page_cluster,
1090 .maxlen = sizeof(int),
1092 .proc_handler = &proc_dointvec,
1095 .ctl_name = VM_DIRTY_BACKGROUND,
1096 .procname = "dirty_background_ratio",
1097 .data = &dirty_background_ratio,
1098 .maxlen = sizeof(dirty_background_ratio),
1100 .proc_handler = &dirty_background_ratio_handler,
1101 .strategy = &sysctl_intvec,
1103 .extra2 = &one_hundred,
1106 .ctl_name = CTL_UNNUMBERED,
1107 .procname = "dirty_background_bytes",
1108 .data = &dirty_background_bytes,
1109 .maxlen = sizeof(dirty_background_bytes),
1111 .proc_handler = &dirty_background_bytes_handler,
1112 .strategy = &sysctl_intvec,
1116 .ctl_name = VM_DIRTY_RATIO,
1117 .procname = "dirty_ratio",
1118 .data = &vm_dirty_ratio,
1119 .maxlen = sizeof(vm_dirty_ratio),
1121 .proc_handler = &dirty_ratio_handler,
1122 .strategy = &sysctl_intvec,
1124 .extra2 = &one_hundred,
1127 .ctl_name = CTL_UNNUMBERED,
1128 .procname = "dirty_bytes",
1129 .data = &vm_dirty_bytes,
1130 .maxlen = sizeof(vm_dirty_bytes),
1132 .proc_handler = &dirty_bytes_handler,
1133 .strategy = &sysctl_intvec,
1134 .extra1 = &dirty_bytes_min,
1137 .procname = "dirty_writeback_centisecs",
1138 .data = &dirty_writeback_interval,
1139 .maxlen = sizeof(dirty_writeback_interval),
1141 .proc_handler = &dirty_writeback_centisecs_handler,
1144 .procname = "dirty_expire_centisecs",
1145 .data = &dirty_expire_interval,
1146 .maxlen = sizeof(dirty_expire_interval),
1148 .proc_handler = &proc_dointvec,
1151 .ctl_name = VM_NR_PDFLUSH_THREADS,
1152 .procname = "nr_pdflush_threads",
1153 .data = &nr_pdflush_threads,
1154 .maxlen = sizeof nr_pdflush_threads,
1155 .mode = 0444 /* read-only*/,
1156 .proc_handler = &proc_dointvec,
1159 .ctl_name = VM_SWAPPINESS,
1160 .procname = "swappiness",
1161 .data = &vm_swappiness,
1162 .maxlen = sizeof(vm_swappiness),
1164 .proc_handler = &proc_dointvec_minmax,
1165 .strategy = &sysctl_intvec,
1167 .extra2 = &one_hundred,
1169 #ifdef CONFIG_HUGETLB_PAGE
1171 .procname = "nr_hugepages",
1173 .maxlen = sizeof(unsigned long),
1175 .proc_handler = &hugetlb_sysctl_handler,
1176 .extra1 = (void *)&hugetlb_zero,
1177 .extra2 = (void *)&hugetlb_infinity,
1180 .ctl_name = VM_HUGETLB_GROUP,
1181 .procname = "hugetlb_shm_group",
1182 .data = &sysctl_hugetlb_shm_group,
1183 .maxlen = sizeof(gid_t),
1185 .proc_handler = &proc_dointvec,
1188 .ctl_name = CTL_UNNUMBERED,
1189 .procname = "hugepages_treat_as_movable",
1190 .data = &hugepages_treat_as_movable,
1191 .maxlen = sizeof(int),
1193 .proc_handler = &hugetlb_treat_movable_handler,
1196 .ctl_name = CTL_UNNUMBERED,
1197 .procname = "nr_overcommit_hugepages",
1199 .maxlen = sizeof(unsigned long),
1201 .proc_handler = &hugetlb_overcommit_handler,
1202 .extra1 = (void *)&hugetlb_zero,
1203 .extra2 = (void *)&hugetlb_infinity,
1207 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1208 .procname = "lowmem_reserve_ratio",
1209 .data = &sysctl_lowmem_reserve_ratio,
1210 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1212 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1213 .strategy = &sysctl_intvec,
1216 .ctl_name = VM_DROP_PAGECACHE,
1217 .procname = "drop_caches",
1218 .data = &sysctl_drop_caches,
1219 .maxlen = sizeof(int),
1221 .proc_handler = drop_caches_sysctl_handler,
1222 .strategy = &sysctl_intvec,
1225 .ctl_name = VM_MIN_FREE_KBYTES,
1226 .procname = "min_free_kbytes",
1227 .data = &min_free_kbytes,
1228 .maxlen = sizeof(min_free_kbytes),
1230 .proc_handler = &min_free_kbytes_sysctl_handler,
1231 .strategy = &sysctl_intvec,
1235 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1236 .procname = "percpu_pagelist_fraction",
1237 .data = &percpu_pagelist_fraction,
1238 .maxlen = sizeof(percpu_pagelist_fraction),
1240 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1241 .strategy = &sysctl_intvec,
1242 .extra1 = &min_percpu_pagelist_fract,
1246 .ctl_name = VM_MAX_MAP_COUNT,
1247 .procname = "max_map_count",
1248 .data = &sysctl_max_map_count,
1249 .maxlen = sizeof(sysctl_max_map_count),
1251 .proc_handler = &proc_dointvec
1255 .ctl_name = CTL_UNNUMBERED,
1256 .procname = "nr_trim_pages",
1257 .data = &sysctl_nr_trim_pages,
1258 .maxlen = sizeof(sysctl_nr_trim_pages),
1260 .proc_handler = &proc_dointvec_minmax,
1261 .strategy = &sysctl_intvec,
1266 .ctl_name = VM_LAPTOP_MODE,
1267 .procname = "laptop_mode",
1268 .data = &laptop_mode,
1269 .maxlen = sizeof(laptop_mode),
1271 .proc_handler = &proc_dointvec_jiffies,
1272 .strategy = &sysctl_jiffies,
1275 .ctl_name = VM_BLOCK_DUMP,
1276 .procname = "block_dump",
1277 .data = &block_dump,
1278 .maxlen = sizeof(block_dump),
1280 .proc_handler = &proc_dointvec,
1281 .strategy = &sysctl_intvec,
1285 .ctl_name = VM_VFS_CACHE_PRESSURE,
1286 .procname = "vfs_cache_pressure",
1287 .data = &sysctl_vfs_cache_pressure,
1288 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1290 .proc_handler = &proc_dointvec,
1291 .strategy = &sysctl_intvec,
1294 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1296 .ctl_name = VM_LEGACY_VA_LAYOUT,
1297 .procname = "legacy_va_layout",
1298 .data = &sysctl_legacy_va_layout,
1299 .maxlen = sizeof(sysctl_legacy_va_layout),
1301 .proc_handler = &proc_dointvec,
1302 .strategy = &sysctl_intvec,
1308 .ctl_name = VM_ZONE_RECLAIM_MODE,
1309 .procname = "zone_reclaim_mode",
1310 .data = &zone_reclaim_mode,
1311 .maxlen = sizeof(zone_reclaim_mode),
1313 .proc_handler = &proc_dointvec,
1314 .strategy = &sysctl_intvec,
1318 .ctl_name = VM_MIN_UNMAPPED,
1319 .procname = "min_unmapped_ratio",
1320 .data = &sysctl_min_unmapped_ratio,
1321 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1323 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1324 .strategy = &sysctl_intvec,
1326 .extra2 = &one_hundred,
1329 .ctl_name = VM_MIN_SLAB,
1330 .procname = "min_slab_ratio",
1331 .data = &sysctl_min_slab_ratio,
1332 .maxlen = sizeof(sysctl_min_slab_ratio),
1334 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1335 .strategy = &sysctl_intvec,
1337 .extra2 = &one_hundred,
1342 .ctl_name = CTL_UNNUMBERED,
1343 .procname = "stat_interval",
1344 .data = &sysctl_stat_interval,
1345 .maxlen = sizeof(sysctl_stat_interval),
1347 .proc_handler = &proc_dointvec_jiffies,
1348 .strategy = &sysctl_jiffies,
1352 .ctl_name = CTL_UNNUMBERED,
1353 .procname = "mmap_min_addr",
1354 .data = &dac_mmap_min_addr,
1355 .maxlen = sizeof(unsigned long),
1357 .proc_handler = &mmap_min_addr_handler,
1361 .ctl_name = CTL_UNNUMBERED,
1362 .procname = "numa_zonelist_order",
1363 .data = &numa_zonelist_order,
1364 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1366 .proc_handler = &numa_zonelist_order_handler,
1367 .strategy = &sysctl_string,
1370 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1371 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1373 .ctl_name = VM_VDSO_ENABLED,
1374 .procname = "vdso_enabled",
1375 .data = &vdso_enabled,
1376 .maxlen = sizeof(vdso_enabled),
1378 .proc_handler = &proc_dointvec,
1379 .strategy = &sysctl_intvec,
1383 #ifdef CONFIG_HIGHMEM
1385 .ctl_name = CTL_UNNUMBERED,
1386 .procname = "highmem_is_dirtyable",
1387 .data = &vm_highmem_is_dirtyable,
1388 .maxlen = sizeof(vm_highmem_is_dirtyable),
1390 .proc_handler = &proc_dointvec_minmax,
1391 .strategy = &sysctl_intvec,
1397 .ctl_name = CTL_UNNUMBERED,
1398 .procname = "scan_unevictable_pages",
1399 .data = &scan_unevictable_pages,
1400 .maxlen = sizeof(scan_unevictable_pages),
1402 .proc_handler = &scan_unevictable_handler,
1404 #ifdef CONFIG_MEMORY_FAILURE
1406 .ctl_name = CTL_UNNUMBERED,
1407 .procname = "memory_failure_early_kill",
1408 .data = &sysctl_memory_failure_early_kill,
1409 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1411 .proc_handler = &proc_dointvec_minmax,
1412 .strategy = &sysctl_intvec,
1417 .ctl_name = CTL_UNNUMBERED,
1418 .procname = "memory_failure_recovery",
1419 .data = &sysctl_memory_failure_recovery,
1420 .maxlen = sizeof(sysctl_memory_failure_recovery),
1422 .proc_handler = &proc_dointvec_minmax,
1423 .strategy = &sysctl_intvec,
1430 * NOTE: do not add new entries to this table unless you have read
1431 * Documentation/sysctl/ctl_unnumbered.txt
1436 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1437 static struct ctl_table binfmt_misc_table[] = {
1442 static struct ctl_table fs_table[] = {
1444 .ctl_name = FS_NRINODE,
1445 .procname = "inode-nr",
1446 .data = &inodes_stat,
1447 .maxlen = 2*sizeof(int),
1449 .proc_handler = &proc_dointvec,
1452 .ctl_name = FS_STATINODE,
1453 .procname = "inode-state",
1454 .data = &inodes_stat,
1455 .maxlen = 7*sizeof(int),
1457 .proc_handler = &proc_dointvec,
1460 .procname = "file-nr",
1461 .data = &files_stat,
1462 .maxlen = 3*sizeof(int),
1464 .proc_handler = &proc_nr_files,
1467 .ctl_name = FS_MAXFILE,
1468 .procname = "file-max",
1469 .data = &files_stat.max_files,
1470 .maxlen = sizeof(int),
1472 .proc_handler = &proc_dointvec,
1475 .ctl_name = CTL_UNNUMBERED,
1476 .procname = "nr_open",
1477 .data = &sysctl_nr_open,
1478 .maxlen = sizeof(int),
1480 .proc_handler = &proc_dointvec_minmax,
1481 .extra1 = &sysctl_nr_open_min,
1482 .extra2 = &sysctl_nr_open_max,
1485 .ctl_name = FS_DENTRY,
1486 .procname = "dentry-state",
1487 .data = &dentry_stat,
1488 .maxlen = 6*sizeof(int),
1490 .proc_handler = &proc_dointvec,
1493 .ctl_name = FS_OVERFLOWUID,
1494 .procname = "overflowuid",
1495 .data = &fs_overflowuid,
1496 .maxlen = sizeof(int),
1498 .proc_handler = &proc_dointvec_minmax,
1499 .strategy = &sysctl_intvec,
1500 .extra1 = &minolduid,
1501 .extra2 = &maxolduid,
1504 .ctl_name = FS_OVERFLOWGID,
1505 .procname = "overflowgid",
1506 .data = &fs_overflowgid,
1507 .maxlen = sizeof(int),
1509 .proc_handler = &proc_dointvec_minmax,
1510 .strategy = &sysctl_intvec,
1511 .extra1 = &minolduid,
1512 .extra2 = &maxolduid,
1514 #ifdef CONFIG_FILE_LOCKING
1516 .ctl_name = FS_LEASES,
1517 .procname = "leases-enable",
1518 .data = &leases_enable,
1519 .maxlen = sizeof(int),
1521 .proc_handler = &proc_dointvec,
1524 #ifdef CONFIG_DNOTIFY
1526 .ctl_name = FS_DIR_NOTIFY,
1527 .procname = "dir-notify-enable",
1528 .data = &dir_notify_enable,
1529 .maxlen = sizeof(int),
1531 .proc_handler = &proc_dointvec,
1535 #ifdef CONFIG_FILE_LOCKING
1537 .ctl_name = FS_LEASE_TIME,
1538 .procname = "lease-break-time",
1539 .data = &lease_break_time,
1540 .maxlen = sizeof(int),
1542 .proc_handler = &proc_dointvec,
1547 .procname = "aio-nr",
1549 .maxlen = sizeof(aio_nr),
1551 .proc_handler = &proc_doulongvec_minmax,
1554 .procname = "aio-max-nr",
1555 .data = &aio_max_nr,
1556 .maxlen = sizeof(aio_max_nr),
1558 .proc_handler = &proc_doulongvec_minmax,
1560 #endif /* CONFIG_AIO */
1561 #ifdef CONFIG_INOTIFY_USER
1563 .ctl_name = FS_INOTIFY,
1564 .procname = "inotify",
1566 .child = inotify_table,
1571 .procname = "epoll",
1573 .child = epoll_table,
1578 .ctl_name = KERN_SETUID_DUMPABLE,
1579 .procname = "suid_dumpable",
1580 .data = &suid_dumpable,
1581 .maxlen = sizeof(int),
1583 .proc_handler = &proc_dointvec_minmax,
1584 .strategy = &sysctl_intvec,
1588 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1590 .ctl_name = CTL_UNNUMBERED,
1591 .procname = "binfmt_misc",
1593 .child = binfmt_misc_table,
1597 * NOTE: do not add new entries to this table unless you have read
1598 * Documentation/sysctl/ctl_unnumbered.txt
1603 static struct ctl_table debug_table[] = {
1604 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1606 .ctl_name = CTL_UNNUMBERED,
1607 .procname = "exception-trace",
1608 .data = &show_unhandled_signals,
1609 .maxlen = sizeof(int),
1611 .proc_handler = proc_dointvec
1617 static struct ctl_table dev_table[] = {
1621 static DEFINE_SPINLOCK(sysctl_lock);
1623 /* called under sysctl_lock */
1624 static int use_table(struct ctl_table_header *p)
1626 if (unlikely(p->unregistering))
1632 /* called under sysctl_lock */
1633 static void unuse_table(struct ctl_table_header *p)
1636 if (unlikely(p->unregistering))
1637 complete(p->unregistering);
1640 /* called under sysctl_lock, will reacquire if has to wait */
1641 static void start_unregistering(struct ctl_table_header *p)
1644 * if p->used is 0, nobody will ever touch that entry again;
1645 * we'll eliminate all paths to it before dropping sysctl_lock
1647 if (unlikely(p->used)) {
1648 struct completion wait;
1649 init_completion(&wait);
1650 p->unregistering = &wait;
1651 spin_unlock(&sysctl_lock);
1652 wait_for_completion(&wait);
1653 spin_lock(&sysctl_lock);
1655 /* anything non-NULL; we'll never dereference it */
1656 p->unregistering = ERR_PTR(-EINVAL);
1659 * do not remove from the list until nobody holds it; walking the
1660 * list in do_sysctl() relies on that.
1662 list_del_init(&p->ctl_entry);
1665 void sysctl_head_get(struct ctl_table_header *head)
1667 spin_lock(&sysctl_lock);
1669 spin_unlock(&sysctl_lock);
1672 void sysctl_head_put(struct ctl_table_header *head)
1674 spin_lock(&sysctl_lock);
1677 spin_unlock(&sysctl_lock);
1680 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1684 spin_lock(&sysctl_lock);
1685 if (!use_table(head))
1686 head = ERR_PTR(-ENOENT);
1687 spin_unlock(&sysctl_lock);
1691 void sysctl_head_finish(struct ctl_table_header *head)
1695 spin_lock(&sysctl_lock);
1697 spin_unlock(&sysctl_lock);
1700 static struct ctl_table_set *
1701 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1703 struct ctl_table_set *set = &root->default_set;
1705 set = root->lookup(root, namespaces);
1709 static struct list_head *
1710 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1712 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1716 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1717 struct ctl_table_header *prev)
1719 struct ctl_table_root *root;
1720 struct list_head *header_list;
1721 struct ctl_table_header *head;
1722 struct list_head *tmp;
1724 spin_lock(&sysctl_lock);
1727 tmp = &prev->ctl_entry;
1731 tmp = &root_table_header.ctl_entry;
1733 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1735 if (!use_table(head))
1737 spin_unlock(&sysctl_lock);
1742 header_list = lookup_header_list(root, namespaces);
1743 if (tmp != header_list)
1747 root = list_entry(root->root_list.next,
1748 struct ctl_table_root, root_list);
1749 if (root == &sysctl_table_root)
1751 header_list = lookup_header_list(root, namespaces);
1752 } while (list_empty(header_list));
1753 tmp = header_list->next;
1756 spin_unlock(&sysctl_lock);
1760 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1762 return __sysctl_head_next(current->nsproxy, prev);
1765 void register_sysctl_root(struct ctl_table_root *root)
1767 spin_lock(&sysctl_lock);
1768 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1769 spin_unlock(&sysctl_lock);
1772 #ifdef CONFIG_SYSCTL_SYSCALL
1773 /* Perform the actual read/write of a sysctl table entry. */
1774 static int do_sysctl_strategy(struct ctl_table_root *root,
1775 struct ctl_table *table,
1776 void __user *oldval, size_t __user *oldlenp,
1777 void __user *newval, size_t newlen)
1785 if (sysctl_perm(root, table, op))
1788 if (table->strategy) {
1789 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1796 /* If there is no strategy routine, or if the strategy returns
1797 * zero, proceed with automatic r/w */
1798 if (table->data && table->maxlen) {
1799 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1806 static int parse_table(int __user *name, int nlen,
1807 void __user *oldval, size_t __user *oldlenp,
1808 void __user *newval, size_t newlen,
1809 struct ctl_table_root *root,
1810 struct ctl_table *table)
1816 if (get_user(n, name))
1818 for ( ; table->ctl_name || table->procname; table++) {
1819 if (!table->ctl_name)
1821 if (n == table->ctl_name) {
1824 if (sysctl_perm(root, table, MAY_EXEC))
1828 table = table->child;
1831 error = do_sysctl_strategy(root, table,
1840 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1841 void __user *newval, size_t newlen)
1843 struct ctl_table_header *head;
1844 int error = -ENOTDIR;
1846 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1850 if (!oldlenp || get_user(old_len, oldlenp))
1854 for (head = sysctl_head_next(NULL); head;
1855 head = sysctl_head_next(head)) {
1856 error = parse_table(name, nlen, oldval, oldlenp,
1858 head->root, head->ctl_table);
1859 if (error != -ENOTDIR) {
1860 sysctl_head_finish(head);
1867 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1869 struct __sysctl_args tmp;
1872 if (copy_from_user(&tmp, args, sizeof(tmp)))
1875 error = deprecated_sysctl_warning(&tmp);
1880 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1881 tmp.newval, tmp.newlen);
1886 #endif /* CONFIG_SYSCTL_SYSCALL */
1889 * sysctl_perm does NOT grant the superuser all rights automatically, because
1890 * some sysctl variables are readonly even to root.
1893 static int test_perm(int mode, int op)
1895 if (!current_euid())
1897 else if (in_egroup_p(0))
1899 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1904 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1909 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1913 if (root->permissions)
1914 mode = root->permissions(root, current->nsproxy, table);
1918 return test_perm(mode, op);
1921 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1923 for (; table->ctl_name || table->procname; table++) {
1924 table->parent = parent;
1926 sysctl_set_parent(table, table->child);
1930 static __init int sysctl_init(void)
1932 sysctl_set_parent(NULL, root_table);
1933 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1936 err = sysctl_check_table(current->nsproxy, root_table);
1942 core_initcall(sysctl_init);
1944 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1945 struct ctl_table *table)
1947 struct ctl_table *p;
1948 const char *s = branch->procname;
1950 /* branch should have named subdirectory as its first element */
1951 if (!s || !branch->child)
1954 /* ... and nothing else */
1955 if (branch[1].procname || branch[1].ctl_name)
1958 /* table should contain subdirectory with the same name */
1959 for (p = table; p->procname || p->ctl_name; p++) {
1962 if (p->procname && strcmp(p->procname, s) == 0)
1968 /* see if attaching q to p would be an improvement */
1969 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1971 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1972 struct ctl_table *next;
1974 int not_in_parent = !p->attached_by;
1976 while ((next = is_branch_in(by, to)) != NULL) {
1977 if (by == q->attached_by)
1979 if (to == p->attached_by)
1985 if (is_better && not_in_parent) {
1986 q->attached_by = by;
1987 q->attached_to = to;
1993 * __register_sysctl_paths - register a sysctl hierarchy
1994 * @root: List of sysctl headers to register on
1995 * @namespaces: Data to compute which lists of sysctl entries are visible
1996 * @path: The path to the directory the sysctl table is in.
1997 * @table: the top-level table structure
1999 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2000 * array. A completely 0 filled entry terminates the table.
2002 * The members of the &struct ctl_table structure are used as follows:
2004 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
2005 * must be unique within that level of sysctl
2007 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
2008 * enter a sysctl file
2010 * data - a pointer to data for use by proc_handler
2012 * maxlen - the maximum size in bytes of the data
2014 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
2016 * child - a pointer to the child sysctl table if this entry is a directory, or
2019 * proc_handler - the text handler routine (described below)
2021 * strategy - the strategy routine (described below)
2023 * de - for internal use by the sysctl routines
2025 * extra1, extra2 - extra pointers usable by the proc handler routines
2027 * Leaf nodes in the sysctl tree will be represented by a single file
2028 * under /proc; non-leaf nodes will be represented by directories.
2030 * sysctl(2) can automatically manage read and write requests through
2031 * the sysctl table. The data and maxlen fields of the ctl_table
2032 * struct enable minimal validation of the values being written to be
2033 * performed, and the mode field allows minimal authentication.
2035 * More sophisticated management can be enabled by the provision of a
2036 * strategy routine with the table entry. This will be called before
2037 * any automatic read or write of the data is performed.
2039 * The strategy routine may return
2041 * < 0 - Error occurred (error is passed to user process)
2043 * 0 - OK - proceed with automatic read or write.
2045 * > 0 - OK - read or write has been done by the strategy routine, so
2046 * return immediately.
2048 * There must be a proc_handler routine for any terminal nodes
2049 * mirrored under /proc/sys (non-terminals are handled by a built-in
2050 * directory handler). Several default handlers are available to
2051 * cover common cases -
2053 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
2054 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
2055 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
2057 * It is the handler's job to read the input buffer from user memory
2058 * and process it. The handler should return 0 on success.
2060 * This routine returns %NULL on a failure to register, and a pointer
2061 * to the table header on success.
2063 struct ctl_table_header *__register_sysctl_paths(
2064 struct ctl_table_root *root,
2065 struct nsproxy *namespaces,
2066 const struct ctl_path *path, struct ctl_table *table)
2068 struct ctl_table_header *header;
2069 struct ctl_table *new, **prevp;
2070 unsigned int n, npath;
2071 struct ctl_table_set *set;
2073 /* Count the path components */
2074 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2078 * For each path component, allocate a 2-element ctl_table array.
2079 * The first array element will be filled with the sysctl entry
2080 * for this, the second will be the sentinel (ctl_name == 0).
2082 * We allocate everything in one go so that we don't have to
2083 * worry about freeing additional memory in unregister_sysctl_table.
2085 header = kzalloc(sizeof(struct ctl_table_header) +
2086 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2090 new = (struct ctl_table *) (header + 1);
2092 /* Now connect the dots */
2093 prevp = &header->ctl_table;
2094 for (n = 0; n < npath; ++n, ++path) {
2095 /* Copy the procname */
2096 new->procname = path->procname;
2097 new->ctl_name = path->ctl_name;
2101 prevp = &new->child;
2106 header->ctl_table_arg = table;
2108 INIT_LIST_HEAD(&header->ctl_entry);
2110 header->unregistering = NULL;
2111 header->root = root;
2112 sysctl_set_parent(NULL, header->ctl_table);
2114 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2115 if (sysctl_check_table(namespaces, header->ctl_table)) {
2120 spin_lock(&sysctl_lock);
2121 header->set = lookup_header_set(root, namespaces);
2122 header->attached_by = header->ctl_table;
2123 header->attached_to = root_table;
2124 header->parent = &root_table_header;
2125 for (set = header->set; set; set = set->parent) {
2126 struct ctl_table_header *p;
2127 list_for_each_entry(p, &set->list, ctl_entry) {
2128 if (p->unregistering)
2130 try_attach(p, header);
2133 header->parent->count++;
2134 list_add_tail(&header->ctl_entry, &header->set->list);
2135 spin_unlock(&sysctl_lock);
2141 * register_sysctl_table_path - register a sysctl table hierarchy
2142 * @path: The path to the directory the sysctl table is in.
2143 * @table: the top-level table structure
2145 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2146 * array. A completely 0 filled entry terminates the table.
2148 * See __register_sysctl_paths for more details.
2150 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2151 struct ctl_table *table)
2153 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2158 * register_sysctl_table - register a sysctl table hierarchy
2159 * @table: the top-level table structure
2161 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2162 * array. A completely 0 filled entry terminates the table.
2164 * See register_sysctl_paths for more details.
2166 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2168 static const struct ctl_path null_path[] = { {} };
2170 return register_sysctl_paths(null_path, table);
2174 * unregister_sysctl_table - unregister a sysctl table hierarchy
2175 * @header: the header returned from register_sysctl_table
2177 * Unregisters the sysctl table and all children. proc entries may not
2178 * actually be removed until they are no longer used by anyone.
2180 void unregister_sysctl_table(struct ctl_table_header * header)
2187 spin_lock(&sysctl_lock);
2188 start_unregistering(header);
2189 if (!--header->parent->count) {
2191 kfree(header->parent);
2193 if (!--header->count)
2195 spin_unlock(&sysctl_lock);
2198 int sysctl_is_seen(struct ctl_table_header *p)
2200 struct ctl_table_set *set = p->set;
2202 spin_lock(&sysctl_lock);
2203 if (p->unregistering)
2205 else if (!set->is_seen)
2208 res = set->is_seen(set);
2209 spin_unlock(&sysctl_lock);
2213 void setup_sysctl_set(struct ctl_table_set *p,
2214 struct ctl_table_set *parent,
2215 int (*is_seen)(struct ctl_table_set *))
2217 INIT_LIST_HEAD(&p->list);
2218 p->parent = parent ? parent : &sysctl_table_root.default_set;
2219 p->is_seen = is_seen;
2222 #else /* !CONFIG_SYSCTL */
2223 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2228 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2229 struct ctl_table *table)
2234 void unregister_sysctl_table(struct ctl_table_header * table)
2238 void setup_sysctl_set(struct ctl_table_set *p,
2239 struct ctl_table_set *parent,
2240 int (*is_seen)(struct ctl_table_set *))
2244 void sysctl_head_put(struct ctl_table_header *head)
2248 #endif /* CONFIG_SYSCTL */
2254 #ifdef CONFIG_PROC_SYSCTL
2256 static int _proc_do_string(void* data, int maxlen, int write,
2257 void __user *buffer,
2258 size_t *lenp, loff_t *ppos)
2264 if (!data || !maxlen || !*lenp) {
2272 while (len < *lenp) {
2273 if (get_user(c, p++))
2275 if (c == 0 || c == '\n')
2281 if(copy_from_user(data, buffer, len))
2283 ((char *) data)[len] = 0;
2301 if(copy_to_user(buffer, data, len))
2304 if(put_user('\n', ((char __user *) buffer) + len))
2315 * proc_dostring - read a string sysctl
2316 * @table: the sysctl table
2317 * @write: %TRUE if this is a write to the sysctl file
2318 * @buffer: the user buffer
2319 * @lenp: the size of the user buffer
2320 * @ppos: file position
2322 * Reads/writes a string from/to the user buffer. If the kernel
2323 * buffer provided is not large enough to hold the string, the
2324 * string is truncated. The copied string is %NULL-terminated.
2325 * If the string is being read by the user process, it is copied
2326 * and a newline '\n' is added. It is truncated if the buffer is
2329 * Returns 0 on success.
2331 int proc_dostring(struct ctl_table *table, int write,
2332 void __user *buffer, size_t *lenp, loff_t *ppos)
2334 return _proc_do_string(table->data, table->maxlen, write,
2335 buffer, lenp, ppos);
2339 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2341 int write, void *data)
2344 *valp = *negp ? -*lvalp : *lvalp;
2349 *lvalp = (unsigned long)-val;
2352 *lvalp = (unsigned long)val;
2358 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2359 int write, void __user *buffer,
2360 size_t *lenp, loff_t *ppos,
2361 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2362 int write, void *data),
2365 #define TMPBUFLEN 21
2366 int *i, vleft, first = 1, neg;
2370 char buf[TMPBUFLEN], *p;
2371 char __user *s = buffer;
2373 if (!tbl_data || !table->maxlen || !*lenp ||
2374 (*ppos && !write)) {
2379 i = (int *) tbl_data;
2380 vleft = table->maxlen / sizeof(*i);
2384 conv = do_proc_dointvec_conv;
2386 for (; left && vleft--; i++, first=0) {
2401 if (len > sizeof(buf) - 1)
2402 len = sizeof(buf) - 1;
2403 if (copy_from_user(buf, s, len))
2407 if (*p == '-' && left > 1) {
2411 if (*p < '0' || *p > '9')
2414 lval = simple_strtoul(p, &p, 0);
2417 if ((len < left) && *p && !isspace(*p))
2422 if (conv(&neg, &lval, i, 1, data))
2429 if (conv(&neg, &lval, i, 0, data))
2432 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2436 if(copy_to_user(s, buf, len))
2443 if (!write && !first && left) {
2444 if(put_user('\n', s))
2451 if (get_user(c, s++))
2466 static int do_proc_dointvec(struct ctl_table *table, int write,
2467 void __user *buffer, size_t *lenp, loff_t *ppos,
2468 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2469 int write, void *data),
2472 return __do_proc_dointvec(table->data, table, write,
2473 buffer, lenp, ppos, conv, data);
2477 * proc_dointvec - read a vector of integers
2478 * @table: the sysctl table
2479 * @write: %TRUE if this is a write to the sysctl file
2480 * @buffer: the user buffer
2481 * @lenp: the size of the user buffer
2482 * @ppos: file position
2484 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2485 * values from/to the user buffer, treated as an ASCII string.
2487 * Returns 0 on success.
2489 int proc_dointvec(struct ctl_table *table, int write,
2490 void __user *buffer, size_t *lenp, loff_t *ppos)
2492 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2497 * Taint values can only be increased
2498 * This means we can safely use a temporary.
2500 static int proc_taint(struct ctl_table *table, int write,
2501 void __user *buffer, size_t *lenp, loff_t *ppos)
2504 unsigned long tmptaint = get_taint();
2507 if (write && !capable(CAP_SYS_ADMIN))
2512 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2518 * Poor man's atomic or. Not worth adding a primitive
2519 * to everyone's atomic.h for this
2522 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2523 if ((tmptaint >> i) & 1)
2531 struct do_proc_dointvec_minmax_conv_param {
2536 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2538 int write, void *data)
2540 struct do_proc_dointvec_minmax_conv_param *param = data;
2542 int val = *negp ? -*lvalp : *lvalp;
2543 if ((param->min && *param->min > val) ||
2544 (param->max && *param->max < val))
2551 *lvalp = (unsigned long)-val;
2554 *lvalp = (unsigned long)val;
2561 * proc_dointvec_minmax - read a vector of integers with min/max values
2562 * @table: the sysctl table
2563 * @write: %TRUE if this is a write to the sysctl file
2564 * @buffer: the user buffer
2565 * @lenp: the size of the user buffer
2566 * @ppos: file position
2568 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2569 * values from/to the user buffer, treated as an ASCII string.
2571 * This routine will ensure the values are within the range specified by
2572 * table->extra1 (min) and table->extra2 (max).
2574 * Returns 0 on success.
2576 int proc_dointvec_minmax(struct ctl_table *table, int write,
2577 void __user *buffer, size_t *lenp, loff_t *ppos)
2579 struct do_proc_dointvec_minmax_conv_param param = {
2580 .min = (int *) table->extra1,
2581 .max = (int *) table->extra2,
2583 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2584 do_proc_dointvec_minmax_conv, ¶m);
2587 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2588 void __user *buffer,
2589 size_t *lenp, loff_t *ppos,
2590 unsigned long convmul,
2591 unsigned long convdiv)
2593 #define TMPBUFLEN 21
2594 unsigned long *i, *min, *max, val;
2595 int vleft, first=1, neg;
2597 char buf[TMPBUFLEN], *p;
2598 char __user *s = buffer;
2600 if (!data || !table->maxlen || !*lenp ||
2601 (*ppos && !write)) {
2606 i = (unsigned long *) data;
2607 min = (unsigned long *) table->extra1;
2608 max = (unsigned long *) table->extra2;
2609 vleft = table->maxlen / sizeof(unsigned long);
2612 for (; left && vleft--; i++, min++, max++, first=0) {
2627 if (len > TMPBUFLEN-1)
2629 if (copy_from_user(buf, s, len))
2633 if (*p == '-' && left > 1) {
2637 if (*p < '0' || *p > '9')
2639 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2641 if ((len < left) && *p && !isspace(*p))
2650 if ((min && val < *min) || (max && val > *max))
2657 sprintf(p, "%lu", convdiv * (*i) / convmul);
2661 if(copy_to_user(s, buf, len))
2668 if (!write && !first && left) {
2669 if(put_user('\n', s))
2676 if (get_user(c, s++))
2691 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2692 void __user *buffer,
2693 size_t *lenp, loff_t *ppos,
2694 unsigned long convmul,
2695 unsigned long convdiv)
2697 return __do_proc_doulongvec_minmax(table->data, table, write,
2698 buffer, lenp, ppos, convmul, convdiv);
2702 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2703 * @table: the sysctl table
2704 * @write: %TRUE if this is a write to the sysctl file
2705 * @buffer: the user buffer
2706 * @lenp: the size of the user buffer
2707 * @ppos: file position
2709 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2710 * values from/to the user buffer, treated as an ASCII string.
2712 * This routine will ensure the values are within the range specified by
2713 * table->extra1 (min) and table->extra2 (max).
2715 * Returns 0 on success.
2717 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2718 void __user *buffer, size_t *lenp, loff_t *ppos)
2720 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2724 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2725 * @table: the sysctl table
2726 * @write: %TRUE if this is a write to the sysctl file
2727 * @buffer: the user buffer
2728 * @lenp: the size of the user buffer
2729 * @ppos: file position
2731 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2732 * values from/to the user buffer, treated as an ASCII string. The values
2733 * are treated as milliseconds, and converted to jiffies when they are stored.
2735 * This routine will ensure the values are within the range specified by
2736 * table->extra1 (min) and table->extra2 (max).
2738 * Returns 0 on success.
2740 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2741 void __user *buffer,
2742 size_t *lenp, loff_t *ppos)
2744 return do_proc_doulongvec_minmax(table, write, buffer,
2745 lenp, ppos, HZ, 1000l);
2749 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2751 int write, void *data)
2754 if (*lvalp > LONG_MAX / HZ)
2756 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2762 lval = (unsigned long)-val;
2765 lval = (unsigned long)val;
2772 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2774 int write, void *data)
2777 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2779 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2785 lval = (unsigned long)-val;
2788 lval = (unsigned long)val;
2790 *lvalp = jiffies_to_clock_t(lval);
2795 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2797 int write, void *data)
2800 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2806 lval = (unsigned long)-val;
2809 lval = (unsigned long)val;
2811 *lvalp = jiffies_to_msecs(lval);
2817 * proc_dointvec_jiffies - read a vector of integers as seconds
2818 * @table: the sysctl table
2819 * @write: %TRUE if this is a write to the sysctl file
2820 * @buffer: the user buffer
2821 * @lenp: the size of the user buffer
2822 * @ppos: file position
2824 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2825 * values from/to the user buffer, treated as an ASCII string.
2826 * The values read are assumed to be in seconds, and are converted into
2829 * Returns 0 on success.
2831 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2832 void __user *buffer, size_t *lenp, loff_t *ppos)
2834 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2835 do_proc_dointvec_jiffies_conv,NULL);
2839 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2840 * @table: the sysctl table
2841 * @write: %TRUE if this is a write to the sysctl file
2842 * @buffer: the user buffer
2843 * @lenp: the size of the user buffer
2844 * @ppos: pointer to the file position
2846 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2847 * values from/to the user buffer, treated as an ASCII string.
2848 * The values read are assumed to be in 1/USER_HZ seconds, and
2849 * are converted into jiffies.
2851 * Returns 0 on success.
2853 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2854 void __user *buffer, size_t *lenp, loff_t *ppos)
2856 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2857 do_proc_dointvec_userhz_jiffies_conv,NULL);
2861 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2862 * @table: the sysctl table
2863 * @write: %TRUE if this is a write to the sysctl file
2864 * @buffer: the user buffer
2865 * @lenp: the size of the user buffer
2866 * @ppos: file position
2867 * @ppos: the current position in the file
2869 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2870 * values from/to the user buffer, treated as an ASCII string.
2871 * The values read are assumed to be in 1/1000 seconds, and
2872 * are converted into jiffies.
2874 * Returns 0 on success.
2876 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2877 void __user *buffer, size_t *lenp, loff_t *ppos)
2879 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2880 do_proc_dointvec_ms_jiffies_conv, NULL);
2883 static int proc_do_cad_pid(struct ctl_table *table, int write,
2884 void __user *buffer, size_t *lenp, loff_t *ppos)
2886 struct pid *new_pid;
2890 tmp = pid_vnr(cad_pid);
2892 r = __do_proc_dointvec(&tmp, table, write, buffer,
2893 lenp, ppos, NULL, NULL);
2897 new_pid = find_get_pid(tmp);
2901 put_pid(xchg(&cad_pid, new_pid));
2905 #else /* CONFIG_PROC_FS */
2907 int proc_dostring(struct ctl_table *table, int write,
2908 void __user *buffer, size_t *lenp, loff_t *ppos)
2913 int proc_dointvec(struct ctl_table *table, int write,
2914 void __user *buffer, size_t *lenp, loff_t *ppos)
2919 int proc_dointvec_minmax(struct ctl_table *table, int write,
2920 void __user *buffer, size_t *lenp, loff_t *ppos)
2925 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2926 void __user *buffer, size_t *lenp, loff_t *ppos)
2931 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2932 void __user *buffer, size_t *lenp, loff_t *ppos)
2937 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2938 void __user *buffer, size_t *lenp, loff_t *ppos)
2943 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2944 void __user *buffer, size_t *lenp, loff_t *ppos)
2949 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2950 void __user *buffer,
2951 size_t *lenp, loff_t *ppos)
2957 #endif /* CONFIG_PROC_FS */
2960 #ifdef CONFIG_SYSCTL_SYSCALL
2962 * General sysctl support routines
2965 /* The generic sysctl data routine (used if no strategy routine supplied) */
2966 int sysctl_data(struct ctl_table *table,
2967 void __user *oldval, size_t __user *oldlenp,
2968 void __user *newval, size_t newlen)
2972 /* Get out of I don't have a variable */
2973 if (!table->data || !table->maxlen)
2976 if (oldval && oldlenp) {
2977 if (get_user(len, oldlenp))
2980 if (len > table->maxlen)
2981 len = table->maxlen;
2982 if (copy_to_user(oldval, table->data, len))
2984 if (put_user(len, oldlenp))
2989 if (newval && newlen) {
2990 if (newlen > table->maxlen)
2991 newlen = table->maxlen;
2993 if (copy_from_user(table->data, newval, newlen))
2999 /* The generic string strategy routine: */
3000 int sysctl_string(struct ctl_table *table,
3001 void __user *oldval, size_t __user *oldlenp,
3002 void __user *newval, size_t newlen)
3004 if (!table->data || !table->maxlen)
3007 if (oldval && oldlenp) {
3009 if (get_user(bufsize, oldlenp))
3012 size_t len = strlen(table->data), copied;
3014 /* This shouldn't trigger for a well-formed sysctl */
3015 if (len > table->maxlen)
3016 len = table->maxlen;
3018 /* Copy up to a max of bufsize-1 bytes of the string */
3019 copied = (len >= bufsize) ? bufsize - 1 : len;
3021 if (copy_to_user(oldval, table->data, copied) ||
3022 put_user(0, (char __user *)(oldval + copied)))
3024 if (put_user(len, oldlenp))
3028 if (newval && newlen) {
3029 size_t len = newlen;
3030 if (len > table->maxlen)
3031 len = table->maxlen;
3032 if(copy_from_user(table->data, newval, len))
3034 if (len == table->maxlen)
3036 ((char *) table->data)[len] = 0;
3042 * This function makes sure that all of the integers in the vector
3043 * are between the minimum and maximum values given in the arrays
3044 * table->extra1 and table->extra2, respectively.
3046 int sysctl_intvec(struct ctl_table *table,
3047 void __user *oldval, size_t __user *oldlenp,
3048 void __user *newval, size_t newlen)
3051 if (newval && newlen) {
3052 int __user *vec = (int __user *) newval;
3053 int *min = (int *) table->extra1;
3054 int *max = (int *) table->extra2;
3058 if (newlen % sizeof(int) != 0)
3061 if (!table->extra1 && !table->extra2)
3064 if (newlen > table->maxlen)
3065 newlen = table->maxlen;
3066 length = newlen / sizeof(int);
3068 for (i = 0; i < length; i++) {
3070 if (get_user(value, vec + i))
3072 if (min && value < min[i])
3074 if (max && value > max[i])
3081 /* Strategy function to convert jiffies to seconds */
3082 int sysctl_jiffies(struct ctl_table *table,
3083 void __user *oldval, size_t __user *oldlenp,
3084 void __user *newval, size_t newlen)
3086 if (oldval && oldlenp) {
3089 if (get_user(olen, oldlenp))
3094 if (olen < sizeof(int))
3097 val = *(int *)(table->data) / HZ;
3098 if (put_user(val, (int __user *)oldval))
3100 if (put_user(sizeof(int), oldlenp))
3104 if (newval && newlen) {
3106 if (newlen != sizeof(int))
3108 if (get_user(new, (int __user *)newval))
3110 *(int *)(table->data) = new*HZ;
3115 /* Strategy function to convert jiffies to seconds */
3116 int sysctl_ms_jiffies(struct ctl_table *table,
3117 void __user *oldval, size_t __user *oldlenp,
3118 void __user *newval, size_t newlen)
3120 if (oldval && oldlenp) {
3123 if (get_user(olen, oldlenp))
3128 if (olen < sizeof(int))
3131 val = jiffies_to_msecs(*(int *)(table->data));
3132 if (put_user(val, (int __user *)oldval))
3134 if (put_user(sizeof(int), oldlenp))
3138 if (newval && newlen) {
3140 if (newlen != sizeof(int))
3142 if (get_user(new, (int __user *)newval))
3144 *(int *)(table->data) = msecs_to_jiffies(new);
3151 #else /* CONFIG_SYSCTL_SYSCALL */
3154 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3156 struct __sysctl_args tmp;
3159 if (copy_from_user(&tmp, args, sizeof(tmp)))
3162 error = deprecated_sysctl_warning(&tmp);
3164 /* If no error reading the parameters then just -ENOSYS ... */
3171 int sysctl_data(struct ctl_table *table,
3172 void __user *oldval, size_t __user *oldlenp,
3173 void __user *newval, size_t newlen)
3178 int sysctl_string(struct ctl_table *table,
3179 void __user *oldval, size_t __user *oldlenp,
3180 void __user *newval, size_t newlen)
3185 int sysctl_intvec(struct ctl_table *table,
3186 void __user *oldval, size_t __user *oldlenp,
3187 void __user *newval, size_t newlen)
3192 int sysctl_jiffies(struct ctl_table *table,
3193 void __user *oldval, size_t __user *oldlenp,
3194 void __user *newval, size_t newlen)
3199 int sysctl_ms_jiffies(struct ctl_table *table,
3200 void __user *oldval, size_t __user *oldlenp,
3201 void __user *newval, size_t newlen)
3206 #endif /* CONFIG_SYSCTL_SYSCALL */
3208 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3210 static int msg_count;
3211 int name[CTL_MAXNAME];
3214 /* Check args->nlen. */
3215 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3218 /* Read in the sysctl name for better debug message logging */
3219 for (i = 0; i < args->nlen; i++)
3220 if (get_user(name[i], args->name + i))
3223 /* Ignore accesses to kernel.version */
3224 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3227 if (msg_count < 5) {
3230 "warning: process `%s' used the deprecated sysctl "
3231 "system call with ", current->comm);
3232 for (i = 0; i < args->nlen; i++)
3233 printk("%d.", name[i]);
3240 * No sense putting this after each symbol definition, twice,
3241 * exception granted :-)
3243 EXPORT_SYMBOL(proc_dointvec);
3244 EXPORT_SYMBOL(proc_dointvec_jiffies);
3245 EXPORT_SYMBOL(proc_dointvec_minmax);
3246 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3247 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3248 EXPORT_SYMBOL(proc_dostring);
3249 EXPORT_SYMBOL(proc_doulongvec_minmax);
3250 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3251 EXPORT_SYMBOL(register_sysctl_table);
3252 EXPORT_SYMBOL(register_sysctl_paths);
3253 EXPORT_SYMBOL(sysctl_intvec);
3254 EXPORT_SYMBOL(sysctl_jiffies);
3255 EXPORT_SYMBOL(sysctl_ms_jiffies);
3256 EXPORT_SYMBOL(sysctl_string);
3257 EXPORT_SYMBOL(sysctl_data);
3258 EXPORT_SYMBOL(unregister_sysctl_table);