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/utsname.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/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>
52 #include <asm/uaccess.h>
53 #include <asm/processor.h>
57 #include <asm/stacktrace.h>
61 static int deprecated_sysctl_warning(struct __sysctl_args *args);
63 #if defined(CONFIG_SYSCTL)
65 /* External variables not in a header file. */
67 extern int print_fatal_signals;
68 extern int sysctl_overcommit_memory;
69 extern int sysctl_overcommit_ratio;
70 extern int sysctl_panic_on_oom;
71 extern int sysctl_oom_kill_allocating_task;
72 extern int sysctl_oom_dump_tasks;
73 extern int max_threads;
74 extern int core_uses_pid;
75 extern int suid_dumpable;
76 extern char core_pattern[];
78 extern int min_free_kbytes;
79 extern int pid_max_min, pid_max_max;
80 extern int sysctl_drop_caches;
81 extern int percpu_pagelist_fraction;
82 extern int compat_log;
83 extern int latencytop_enabled;
84 extern int sysctl_nr_open_min, sysctl_nr_open_max;
86 extern int sysctl_nr_trim_pages;
88 #ifdef CONFIG_RCU_TORTURE_TEST
89 extern int rcutorture_runnable;
90 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
92 /* Constants used for minimum and maximum */
93 #ifdef CONFIG_DETECT_SOFTLOCKUP
94 static int sixty = 60;
95 static int neg_one = -1;
98 #if defined(CONFIG_MMU) && defined(CONFIG_FILE_LOCKING)
104 static unsigned long one_ul = 1;
105 static int one_hundred = 100;
107 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
108 static int maxolduid = 65535;
109 static int minolduid;
110 static int min_percpu_pagelist_fract = 8;
112 static int ngroups_max = NGROUPS_MAX;
114 #ifdef CONFIG_MODULES
115 extern char modprobe_path[];
117 #ifdef CONFIG_CHR_DEV_SG
118 extern int sg_big_buff;
122 #include <asm/system.h>
125 #ifdef CONFIG_SPARC64
126 extern int sysctl_tsb_ratio;
130 extern int pwrsw_enabled;
131 extern int unaligned_enabled;
135 #ifdef CONFIG_MATHEMU
136 extern int sysctl_ieee_emulation_warnings;
138 extern int sysctl_userprocess_debug;
139 extern int spin_retry;
142 #ifdef CONFIG_BSD_PROCESS_ACCT
143 extern int acct_parm[];
147 extern int no_unaligned_warning;
148 extern int unaligned_dump_stack;
151 #ifdef CONFIG_RT_MUTEXES
152 extern int max_lock_depth;
155 #ifdef CONFIG_PROC_SYSCTL
156 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
157 void __user *buffer, size_t *lenp, loff_t *ppos);
158 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
159 void __user *buffer, size_t *lenp, loff_t *ppos);
162 static struct ctl_table root_table[];
163 static struct ctl_table_root sysctl_table_root;
164 static struct ctl_table_header root_table_header = {
166 .ctl_table = root_table,
167 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
168 .root = &sysctl_table_root,
169 .set = &sysctl_table_root.default_set,
171 static struct ctl_table_root sysctl_table_root = {
172 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
173 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
176 static struct ctl_table kern_table[];
177 static struct ctl_table vm_table[];
178 static struct ctl_table fs_table[];
179 static struct ctl_table debug_table[];
180 static struct ctl_table dev_table[];
181 extern struct ctl_table random_table[];
182 #ifdef CONFIG_INOTIFY_USER
183 extern struct ctl_table inotify_table[];
186 extern struct ctl_table epoll_table[];
189 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
190 int sysctl_legacy_va_layout;
193 extern int prove_locking;
194 extern int lock_stat;
196 /* The default sysctl tables: */
198 static struct ctl_table root_table[] = {
200 .ctl_name = CTL_KERN,
201 .procname = "kernel",
218 .ctl_name = CTL_DEBUG,
221 .child = debug_table,
230 * NOTE: do not add new entries to this table unless you have read
231 * Documentation/sysctl/ctl_unnumbered.txt
236 #ifdef CONFIG_SCHED_DEBUG
237 static int min_sched_granularity_ns = 100000; /* 100 usecs */
238 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
239 static int min_wakeup_granularity_ns; /* 0 usecs */
240 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
243 static struct ctl_table kern_table[] = {
244 #ifdef CONFIG_SCHED_DEBUG
246 .ctl_name = CTL_UNNUMBERED,
247 .procname = "sched_min_granularity_ns",
248 .data = &sysctl_sched_min_granularity,
249 .maxlen = sizeof(unsigned int),
251 .proc_handler = &sched_nr_latency_handler,
252 .strategy = &sysctl_intvec,
253 .extra1 = &min_sched_granularity_ns,
254 .extra2 = &max_sched_granularity_ns,
257 .ctl_name = CTL_UNNUMBERED,
258 .procname = "sched_latency_ns",
259 .data = &sysctl_sched_latency,
260 .maxlen = sizeof(unsigned int),
262 .proc_handler = &sched_nr_latency_handler,
263 .strategy = &sysctl_intvec,
264 .extra1 = &min_sched_granularity_ns,
265 .extra2 = &max_sched_granularity_ns,
268 .ctl_name = CTL_UNNUMBERED,
269 .procname = "sched_wakeup_granularity_ns",
270 .data = &sysctl_sched_wakeup_granularity,
271 .maxlen = sizeof(unsigned int),
273 .proc_handler = &proc_dointvec_minmax,
274 .strategy = &sysctl_intvec,
275 .extra1 = &min_wakeup_granularity_ns,
276 .extra2 = &max_wakeup_granularity_ns,
279 .ctl_name = CTL_UNNUMBERED,
280 .procname = "sched_shares_ratelimit",
281 .data = &sysctl_sched_shares_ratelimit,
282 .maxlen = sizeof(unsigned int),
284 .proc_handler = &proc_dointvec,
287 .ctl_name = CTL_UNNUMBERED,
288 .procname = "sched_shares_thresh",
289 .data = &sysctl_sched_shares_thresh,
290 .maxlen = sizeof(unsigned int),
292 .proc_handler = &proc_dointvec_minmax,
293 .strategy = &sysctl_intvec,
297 .ctl_name = CTL_UNNUMBERED,
298 .procname = "sched_child_runs_first",
299 .data = &sysctl_sched_child_runs_first,
300 .maxlen = sizeof(unsigned int),
302 .proc_handler = &proc_dointvec,
305 .ctl_name = CTL_UNNUMBERED,
306 .procname = "sched_features",
307 .data = &sysctl_sched_features,
308 .maxlen = sizeof(unsigned int),
310 .proc_handler = &proc_dointvec,
313 .ctl_name = CTL_UNNUMBERED,
314 .procname = "sched_migration_cost",
315 .data = &sysctl_sched_migration_cost,
316 .maxlen = sizeof(unsigned int),
318 .proc_handler = &proc_dointvec,
321 .ctl_name = CTL_UNNUMBERED,
322 .procname = "sched_nr_migrate",
323 .data = &sysctl_sched_nr_migrate,
324 .maxlen = sizeof(unsigned int),
326 .proc_handler = &proc_dointvec,
330 .ctl_name = CTL_UNNUMBERED,
331 .procname = "sched_rt_period_us",
332 .data = &sysctl_sched_rt_period,
333 .maxlen = sizeof(unsigned int),
335 .proc_handler = &sched_rt_handler,
338 .ctl_name = CTL_UNNUMBERED,
339 .procname = "sched_rt_runtime_us",
340 .data = &sysctl_sched_rt_runtime,
341 .maxlen = sizeof(int),
343 .proc_handler = &sched_rt_handler,
346 .ctl_name = CTL_UNNUMBERED,
347 .procname = "sched_compat_yield",
348 .data = &sysctl_sched_compat_yield,
349 .maxlen = sizeof(unsigned int),
351 .proc_handler = &proc_dointvec,
353 #ifdef CONFIG_PROVE_LOCKING
355 .ctl_name = CTL_UNNUMBERED,
356 .procname = "prove_locking",
357 .data = &prove_locking,
358 .maxlen = sizeof(int),
360 .proc_handler = &proc_dointvec,
363 #ifdef CONFIG_LOCK_STAT
365 .ctl_name = CTL_UNNUMBERED,
366 .procname = "lock_stat",
368 .maxlen = sizeof(int),
370 .proc_handler = &proc_dointvec,
374 .ctl_name = KERN_PANIC,
376 .data = &panic_timeout,
377 .maxlen = sizeof(int),
379 .proc_handler = &proc_dointvec,
382 .ctl_name = KERN_CORE_USES_PID,
383 .procname = "core_uses_pid",
384 .data = &core_uses_pid,
385 .maxlen = sizeof(int),
387 .proc_handler = &proc_dointvec,
390 .ctl_name = KERN_CORE_PATTERN,
391 .procname = "core_pattern",
392 .data = core_pattern,
393 .maxlen = CORENAME_MAX_SIZE,
395 .proc_handler = &proc_dostring,
396 .strategy = &sysctl_string,
398 #ifdef CONFIG_PROC_SYSCTL
400 .procname = "tainted",
401 .maxlen = sizeof(long),
403 .proc_handler = &proc_taint,
406 #ifdef CONFIG_LATENCYTOP
408 .procname = "latencytop",
409 .data = &latencytop_enabled,
410 .maxlen = sizeof(int),
412 .proc_handler = &proc_dointvec,
415 #ifdef CONFIG_BLK_DEV_INITRD
417 .ctl_name = KERN_REALROOTDEV,
418 .procname = "real-root-dev",
419 .data = &real_root_dev,
420 .maxlen = sizeof(int),
422 .proc_handler = &proc_dointvec,
426 .ctl_name = CTL_UNNUMBERED,
427 .procname = "print-fatal-signals",
428 .data = &print_fatal_signals,
429 .maxlen = sizeof(int),
431 .proc_handler = &proc_dointvec,
435 .ctl_name = KERN_SPARC_REBOOT,
436 .procname = "reboot-cmd",
437 .data = reboot_command,
440 .proc_handler = &proc_dostring,
441 .strategy = &sysctl_string,
444 .ctl_name = KERN_SPARC_STOP_A,
445 .procname = "stop-a",
446 .data = &stop_a_enabled,
447 .maxlen = sizeof (int),
449 .proc_handler = &proc_dointvec,
452 .ctl_name = KERN_SPARC_SCONS_PWROFF,
453 .procname = "scons-poweroff",
454 .data = &scons_pwroff,
455 .maxlen = sizeof (int),
457 .proc_handler = &proc_dointvec,
460 #ifdef CONFIG_SPARC64
462 .ctl_name = CTL_UNNUMBERED,
463 .procname = "tsb-ratio",
464 .data = &sysctl_tsb_ratio,
465 .maxlen = sizeof (int),
467 .proc_handler = &proc_dointvec,
472 .ctl_name = KERN_HPPA_PWRSW,
473 .procname = "soft-power",
474 .data = &pwrsw_enabled,
475 .maxlen = sizeof (int),
477 .proc_handler = &proc_dointvec,
480 .ctl_name = KERN_HPPA_UNALIGNED,
481 .procname = "unaligned-trap",
482 .data = &unaligned_enabled,
483 .maxlen = sizeof (int),
485 .proc_handler = &proc_dointvec,
489 .ctl_name = KERN_CTLALTDEL,
490 .procname = "ctrl-alt-del",
492 .maxlen = sizeof(int),
494 .proc_handler = &proc_dointvec,
496 #ifdef CONFIG_FUNCTION_TRACER
498 .ctl_name = CTL_UNNUMBERED,
499 .procname = "ftrace_enabled",
500 .data = &ftrace_enabled,
501 .maxlen = sizeof(int),
503 .proc_handler = &ftrace_enable_sysctl,
506 #ifdef CONFIG_STACK_TRACER
508 .ctl_name = CTL_UNNUMBERED,
509 .procname = "stack_tracer_enabled",
510 .data = &stack_tracer_enabled,
511 .maxlen = sizeof(int),
513 .proc_handler = &stack_trace_sysctl,
516 #ifdef CONFIG_TRACING
518 .ctl_name = CTL_UNNUMBERED,
519 .procname = "ftrace_dump_on_oops",
520 .data = &ftrace_dump_on_oops,
521 .maxlen = sizeof(int),
523 .proc_handler = &proc_dointvec,
526 #ifdef CONFIG_MODULES
528 .ctl_name = KERN_MODPROBE,
529 .procname = "modprobe",
530 .data = &modprobe_path,
531 .maxlen = KMOD_PATH_LEN,
533 .proc_handler = &proc_dostring,
534 .strategy = &sysctl_string,
537 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
539 .ctl_name = KERN_HOTPLUG,
540 .procname = "hotplug",
541 .data = &uevent_helper,
542 .maxlen = UEVENT_HELPER_PATH_LEN,
544 .proc_handler = &proc_dostring,
545 .strategy = &sysctl_string,
548 #ifdef CONFIG_CHR_DEV_SG
550 .ctl_name = KERN_SG_BIG_BUFF,
551 .procname = "sg-big-buff",
552 .data = &sg_big_buff,
553 .maxlen = sizeof (int),
555 .proc_handler = &proc_dointvec,
558 #ifdef CONFIG_BSD_PROCESS_ACCT
560 .ctl_name = KERN_ACCT,
563 .maxlen = 3*sizeof(int),
565 .proc_handler = &proc_dointvec,
568 #ifdef CONFIG_MAGIC_SYSRQ
570 .ctl_name = KERN_SYSRQ,
572 .data = &__sysrq_enabled,
573 .maxlen = sizeof (int),
575 .proc_handler = &proc_dointvec,
578 #ifdef CONFIG_PROC_SYSCTL
580 .procname = "cad_pid",
582 .maxlen = sizeof (int),
584 .proc_handler = &proc_do_cad_pid,
588 .ctl_name = KERN_MAX_THREADS,
589 .procname = "threads-max",
590 .data = &max_threads,
591 .maxlen = sizeof(int),
593 .proc_handler = &proc_dointvec,
596 .ctl_name = KERN_RANDOM,
597 .procname = "random",
599 .child = random_table,
602 .ctl_name = KERN_OVERFLOWUID,
603 .procname = "overflowuid",
604 .data = &overflowuid,
605 .maxlen = sizeof(int),
607 .proc_handler = &proc_dointvec_minmax,
608 .strategy = &sysctl_intvec,
609 .extra1 = &minolduid,
610 .extra2 = &maxolduid,
613 .ctl_name = KERN_OVERFLOWGID,
614 .procname = "overflowgid",
615 .data = &overflowgid,
616 .maxlen = sizeof(int),
618 .proc_handler = &proc_dointvec_minmax,
619 .strategy = &sysctl_intvec,
620 .extra1 = &minolduid,
621 .extra2 = &maxolduid,
624 #ifdef CONFIG_MATHEMU
626 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
627 .procname = "ieee_emulation_warnings",
628 .data = &sysctl_ieee_emulation_warnings,
629 .maxlen = sizeof(int),
631 .proc_handler = &proc_dointvec,
635 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
636 .procname = "userprocess_debug",
637 .data = &sysctl_userprocess_debug,
638 .maxlen = sizeof(int),
640 .proc_handler = &proc_dointvec,
644 .ctl_name = KERN_PIDMAX,
645 .procname = "pid_max",
647 .maxlen = sizeof (int),
649 .proc_handler = &proc_dointvec_minmax,
650 .strategy = sysctl_intvec,
651 .extra1 = &pid_max_min,
652 .extra2 = &pid_max_max,
655 .ctl_name = KERN_PANIC_ON_OOPS,
656 .procname = "panic_on_oops",
657 .data = &panic_on_oops,
658 .maxlen = sizeof(int),
660 .proc_handler = &proc_dointvec,
662 #if defined CONFIG_PRINTK
664 .ctl_name = KERN_PRINTK,
665 .procname = "printk",
666 .data = &console_loglevel,
667 .maxlen = 4*sizeof(int),
669 .proc_handler = &proc_dointvec,
672 .ctl_name = KERN_PRINTK_RATELIMIT,
673 .procname = "printk_ratelimit",
674 .data = &printk_ratelimit_state.interval,
675 .maxlen = sizeof(int),
677 .proc_handler = &proc_dointvec_jiffies,
678 .strategy = &sysctl_jiffies,
681 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
682 .procname = "printk_ratelimit_burst",
683 .data = &printk_ratelimit_state.burst,
684 .maxlen = sizeof(int),
686 .proc_handler = &proc_dointvec,
690 .ctl_name = KERN_NGROUPS_MAX,
691 .procname = "ngroups_max",
692 .data = &ngroups_max,
693 .maxlen = sizeof (int),
695 .proc_handler = &proc_dointvec,
697 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
699 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
700 .procname = "unknown_nmi_panic",
701 .data = &unknown_nmi_panic,
702 .maxlen = sizeof (int),
704 .proc_handler = &proc_dointvec,
707 .procname = "nmi_watchdog",
708 .data = &nmi_watchdog_enabled,
709 .maxlen = sizeof (int),
711 .proc_handler = &proc_nmi_enabled,
714 #if defined(CONFIG_X86)
716 .ctl_name = KERN_PANIC_ON_NMI,
717 .procname = "panic_on_unrecovered_nmi",
718 .data = &panic_on_unrecovered_nmi,
719 .maxlen = sizeof(int),
721 .proc_handler = &proc_dointvec,
724 .ctl_name = KERN_BOOTLOADER_TYPE,
725 .procname = "bootloader_type",
726 .data = &bootloader_type,
727 .maxlen = sizeof (int),
729 .proc_handler = &proc_dointvec,
732 .ctl_name = CTL_UNNUMBERED,
733 .procname = "kstack_depth_to_print",
734 .data = &kstack_depth_to_print,
735 .maxlen = sizeof(int),
737 .proc_handler = &proc_dointvec,
740 .ctl_name = CTL_UNNUMBERED,
741 .procname = "io_delay_type",
742 .data = &io_delay_type,
743 .maxlen = sizeof(int),
745 .proc_handler = &proc_dointvec,
748 #if defined(CONFIG_MMU)
750 .ctl_name = KERN_RANDOMIZE,
751 .procname = "randomize_va_space",
752 .data = &randomize_va_space,
753 .maxlen = sizeof(int),
755 .proc_handler = &proc_dointvec,
758 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
760 .ctl_name = KERN_SPIN_RETRY,
761 .procname = "spin_retry",
763 .maxlen = sizeof (int),
765 .proc_handler = &proc_dointvec,
768 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
770 .procname = "acpi_video_flags",
771 .data = &acpi_realmode_flags,
772 .maxlen = sizeof (unsigned long),
774 .proc_handler = &proc_doulongvec_minmax,
779 .ctl_name = KERN_IA64_UNALIGNED,
780 .procname = "ignore-unaligned-usertrap",
781 .data = &no_unaligned_warning,
782 .maxlen = sizeof (int),
784 .proc_handler = &proc_dointvec,
787 .ctl_name = CTL_UNNUMBERED,
788 .procname = "unaligned-dump-stack",
789 .data = &unaligned_dump_stack,
790 .maxlen = sizeof (int),
792 .proc_handler = &proc_dointvec,
795 #ifdef CONFIG_DETECT_SOFTLOCKUP
797 .ctl_name = CTL_UNNUMBERED,
798 .procname = "softlockup_panic",
799 .data = &softlockup_panic,
800 .maxlen = sizeof(int),
802 .proc_handler = &proc_dointvec_minmax,
803 .strategy = &sysctl_intvec,
808 .ctl_name = CTL_UNNUMBERED,
809 .procname = "softlockup_thresh",
810 .data = &softlockup_thresh,
811 .maxlen = sizeof(int),
813 .proc_handler = &proc_dosoftlockup_thresh,
814 .strategy = &sysctl_intvec,
819 #ifdef CONFIG_DETECT_HUNG_TASK
821 .ctl_name = CTL_UNNUMBERED,
822 .procname = "hung_task_panic",
823 .data = &sysctl_hung_task_panic,
824 .maxlen = sizeof(int),
826 .proc_handler = &proc_dointvec_minmax,
827 .strategy = &sysctl_intvec,
832 .ctl_name = CTL_UNNUMBERED,
833 .procname = "hung_task_check_count",
834 .data = &sysctl_hung_task_check_count,
835 .maxlen = sizeof(unsigned long),
837 .proc_handler = &proc_doulongvec_minmax,
838 .strategy = &sysctl_intvec,
841 .ctl_name = CTL_UNNUMBERED,
842 .procname = "hung_task_timeout_secs",
843 .data = &sysctl_hung_task_timeout_secs,
844 .maxlen = sizeof(unsigned long),
846 .proc_handler = &proc_dohung_task_timeout_secs,
847 .strategy = &sysctl_intvec,
850 .ctl_name = CTL_UNNUMBERED,
851 .procname = "hung_task_warnings",
852 .data = &sysctl_hung_task_warnings,
853 .maxlen = sizeof(unsigned long),
855 .proc_handler = &proc_doulongvec_minmax,
856 .strategy = &sysctl_intvec,
861 .ctl_name = KERN_COMPAT_LOG,
862 .procname = "compat-log",
864 .maxlen = sizeof (int),
866 .proc_handler = &proc_dointvec,
869 #ifdef CONFIG_RT_MUTEXES
871 .ctl_name = KERN_MAX_LOCK_DEPTH,
872 .procname = "max_lock_depth",
873 .data = &max_lock_depth,
874 .maxlen = sizeof(int),
876 .proc_handler = &proc_dointvec,
880 .ctl_name = CTL_UNNUMBERED,
881 .procname = "poweroff_cmd",
882 .data = &poweroff_cmd,
883 .maxlen = POWEROFF_CMD_PATH_LEN,
885 .proc_handler = &proc_dostring,
886 .strategy = &sysctl_string,
890 .ctl_name = CTL_UNNUMBERED,
893 .child = key_sysctls,
896 #ifdef CONFIG_RCU_TORTURE_TEST
898 .ctl_name = CTL_UNNUMBERED,
899 .procname = "rcutorture_runnable",
900 .data = &rcutorture_runnable,
901 .maxlen = sizeof(int),
903 .proc_handler = &proc_dointvec,
906 #ifdef CONFIG_UNEVICTABLE_LRU
908 .ctl_name = CTL_UNNUMBERED,
909 .procname = "scan_unevictable_pages",
910 .data = &scan_unevictable_pages,
911 .maxlen = sizeof(scan_unevictable_pages),
913 .proc_handler = &scan_unevictable_handler,
917 * NOTE: do not add new entries to this table unless you have read
918 * Documentation/sysctl/ctl_unnumbered.txt
923 static struct ctl_table vm_table[] = {
925 .ctl_name = VM_OVERCOMMIT_MEMORY,
926 .procname = "overcommit_memory",
927 .data = &sysctl_overcommit_memory,
928 .maxlen = sizeof(sysctl_overcommit_memory),
930 .proc_handler = &proc_dointvec,
933 .ctl_name = VM_PANIC_ON_OOM,
934 .procname = "panic_on_oom",
935 .data = &sysctl_panic_on_oom,
936 .maxlen = sizeof(sysctl_panic_on_oom),
938 .proc_handler = &proc_dointvec,
941 .ctl_name = CTL_UNNUMBERED,
942 .procname = "oom_kill_allocating_task",
943 .data = &sysctl_oom_kill_allocating_task,
944 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
946 .proc_handler = &proc_dointvec,
949 .ctl_name = CTL_UNNUMBERED,
950 .procname = "oom_dump_tasks",
951 .data = &sysctl_oom_dump_tasks,
952 .maxlen = sizeof(sysctl_oom_dump_tasks),
954 .proc_handler = &proc_dointvec,
957 .ctl_name = VM_OVERCOMMIT_RATIO,
958 .procname = "overcommit_ratio",
959 .data = &sysctl_overcommit_ratio,
960 .maxlen = sizeof(sysctl_overcommit_ratio),
962 .proc_handler = &proc_dointvec,
965 .ctl_name = VM_PAGE_CLUSTER,
966 .procname = "page-cluster",
967 .data = &page_cluster,
968 .maxlen = sizeof(int),
970 .proc_handler = &proc_dointvec,
973 .ctl_name = VM_DIRTY_BACKGROUND,
974 .procname = "dirty_background_ratio",
975 .data = &dirty_background_ratio,
976 .maxlen = sizeof(dirty_background_ratio),
978 .proc_handler = &dirty_background_ratio_handler,
979 .strategy = &sysctl_intvec,
981 .extra2 = &one_hundred,
984 .ctl_name = CTL_UNNUMBERED,
985 .procname = "dirty_background_bytes",
986 .data = &dirty_background_bytes,
987 .maxlen = sizeof(dirty_background_bytes),
989 .proc_handler = &dirty_background_bytes_handler,
990 .strategy = &sysctl_intvec,
994 .ctl_name = VM_DIRTY_RATIO,
995 .procname = "dirty_ratio",
996 .data = &vm_dirty_ratio,
997 .maxlen = sizeof(vm_dirty_ratio),
999 .proc_handler = &dirty_ratio_handler,
1000 .strategy = &sysctl_intvec,
1002 .extra2 = &one_hundred,
1005 .ctl_name = CTL_UNNUMBERED,
1006 .procname = "dirty_bytes",
1007 .data = &vm_dirty_bytes,
1008 .maxlen = sizeof(vm_dirty_bytes),
1010 .proc_handler = &dirty_bytes_handler,
1011 .strategy = &sysctl_intvec,
1015 .procname = "dirty_writeback_centisecs",
1016 .data = &dirty_writeback_interval,
1017 .maxlen = sizeof(dirty_writeback_interval),
1019 .proc_handler = &dirty_writeback_centisecs_handler,
1022 .procname = "dirty_expire_centisecs",
1023 .data = &dirty_expire_interval,
1024 .maxlen = sizeof(dirty_expire_interval),
1026 .proc_handler = &proc_dointvec_userhz_jiffies,
1029 .ctl_name = VM_NR_PDFLUSH_THREADS,
1030 .procname = "nr_pdflush_threads",
1031 .data = &nr_pdflush_threads,
1032 .maxlen = sizeof nr_pdflush_threads,
1033 .mode = 0444 /* read-only*/,
1034 .proc_handler = &proc_dointvec,
1037 .ctl_name = VM_SWAPPINESS,
1038 .procname = "swappiness",
1039 .data = &vm_swappiness,
1040 .maxlen = sizeof(vm_swappiness),
1042 .proc_handler = &proc_dointvec_minmax,
1043 .strategy = &sysctl_intvec,
1045 .extra2 = &one_hundred,
1047 #ifdef CONFIG_HUGETLB_PAGE
1049 .procname = "nr_hugepages",
1051 .maxlen = sizeof(unsigned long),
1053 .proc_handler = &hugetlb_sysctl_handler,
1054 .extra1 = (void *)&hugetlb_zero,
1055 .extra2 = (void *)&hugetlb_infinity,
1058 .ctl_name = VM_HUGETLB_GROUP,
1059 .procname = "hugetlb_shm_group",
1060 .data = &sysctl_hugetlb_shm_group,
1061 .maxlen = sizeof(gid_t),
1063 .proc_handler = &proc_dointvec,
1066 .ctl_name = CTL_UNNUMBERED,
1067 .procname = "hugepages_treat_as_movable",
1068 .data = &hugepages_treat_as_movable,
1069 .maxlen = sizeof(int),
1071 .proc_handler = &hugetlb_treat_movable_handler,
1074 .ctl_name = CTL_UNNUMBERED,
1075 .procname = "nr_overcommit_hugepages",
1077 .maxlen = sizeof(unsigned long),
1079 .proc_handler = &hugetlb_overcommit_handler,
1080 .extra1 = (void *)&hugetlb_zero,
1081 .extra2 = (void *)&hugetlb_infinity,
1085 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1086 .procname = "lowmem_reserve_ratio",
1087 .data = &sysctl_lowmem_reserve_ratio,
1088 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1090 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1091 .strategy = &sysctl_intvec,
1094 .ctl_name = VM_DROP_PAGECACHE,
1095 .procname = "drop_caches",
1096 .data = &sysctl_drop_caches,
1097 .maxlen = sizeof(int),
1099 .proc_handler = drop_caches_sysctl_handler,
1100 .strategy = &sysctl_intvec,
1103 .ctl_name = VM_MIN_FREE_KBYTES,
1104 .procname = "min_free_kbytes",
1105 .data = &min_free_kbytes,
1106 .maxlen = sizeof(min_free_kbytes),
1108 .proc_handler = &min_free_kbytes_sysctl_handler,
1109 .strategy = &sysctl_intvec,
1113 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1114 .procname = "percpu_pagelist_fraction",
1115 .data = &percpu_pagelist_fraction,
1116 .maxlen = sizeof(percpu_pagelist_fraction),
1118 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1119 .strategy = &sysctl_intvec,
1120 .extra1 = &min_percpu_pagelist_fract,
1124 .ctl_name = VM_MAX_MAP_COUNT,
1125 .procname = "max_map_count",
1126 .data = &sysctl_max_map_count,
1127 .maxlen = sizeof(sysctl_max_map_count),
1129 .proc_handler = &proc_dointvec
1133 .ctl_name = CTL_UNNUMBERED,
1134 .procname = "nr_trim_pages",
1135 .data = &sysctl_nr_trim_pages,
1136 .maxlen = sizeof(sysctl_nr_trim_pages),
1138 .proc_handler = &proc_dointvec_minmax,
1139 .strategy = &sysctl_intvec,
1144 .ctl_name = VM_LAPTOP_MODE,
1145 .procname = "laptop_mode",
1146 .data = &laptop_mode,
1147 .maxlen = sizeof(laptop_mode),
1149 .proc_handler = &proc_dointvec_jiffies,
1150 .strategy = &sysctl_jiffies,
1153 .ctl_name = VM_BLOCK_DUMP,
1154 .procname = "block_dump",
1155 .data = &block_dump,
1156 .maxlen = sizeof(block_dump),
1158 .proc_handler = &proc_dointvec,
1159 .strategy = &sysctl_intvec,
1163 .ctl_name = VM_VFS_CACHE_PRESSURE,
1164 .procname = "vfs_cache_pressure",
1165 .data = &sysctl_vfs_cache_pressure,
1166 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1168 .proc_handler = &proc_dointvec,
1169 .strategy = &sysctl_intvec,
1172 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1174 .ctl_name = VM_LEGACY_VA_LAYOUT,
1175 .procname = "legacy_va_layout",
1176 .data = &sysctl_legacy_va_layout,
1177 .maxlen = sizeof(sysctl_legacy_va_layout),
1179 .proc_handler = &proc_dointvec,
1180 .strategy = &sysctl_intvec,
1186 .ctl_name = VM_ZONE_RECLAIM_MODE,
1187 .procname = "zone_reclaim_mode",
1188 .data = &zone_reclaim_mode,
1189 .maxlen = sizeof(zone_reclaim_mode),
1191 .proc_handler = &proc_dointvec,
1192 .strategy = &sysctl_intvec,
1196 .ctl_name = VM_MIN_UNMAPPED,
1197 .procname = "min_unmapped_ratio",
1198 .data = &sysctl_min_unmapped_ratio,
1199 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1201 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1202 .strategy = &sysctl_intvec,
1204 .extra2 = &one_hundred,
1207 .ctl_name = VM_MIN_SLAB,
1208 .procname = "min_slab_ratio",
1209 .data = &sysctl_min_slab_ratio,
1210 .maxlen = sizeof(sysctl_min_slab_ratio),
1212 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1213 .strategy = &sysctl_intvec,
1215 .extra2 = &one_hundred,
1220 .ctl_name = CTL_UNNUMBERED,
1221 .procname = "stat_interval",
1222 .data = &sysctl_stat_interval,
1223 .maxlen = sizeof(sysctl_stat_interval),
1225 .proc_handler = &proc_dointvec_jiffies,
1226 .strategy = &sysctl_jiffies,
1229 #ifdef CONFIG_SECURITY
1231 .ctl_name = CTL_UNNUMBERED,
1232 .procname = "mmap_min_addr",
1233 .data = &mmap_min_addr,
1234 .maxlen = sizeof(unsigned long),
1236 .proc_handler = &proc_doulongvec_minmax,
1241 .ctl_name = CTL_UNNUMBERED,
1242 .procname = "numa_zonelist_order",
1243 .data = &numa_zonelist_order,
1244 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1246 .proc_handler = &numa_zonelist_order_handler,
1247 .strategy = &sysctl_string,
1250 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1251 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1253 .ctl_name = VM_VDSO_ENABLED,
1254 .procname = "vdso_enabled",
1255 .data = &vdso_enabled,
1256 .maxlen = sizeof(vdso_enabled),
1258 .proc_handler = &proc_dointvec,
1259 .strategy = &sysctl_intvec,
1263 #ifdef CONFIG_HIGHMEM
1265 .ctl_name = CTL_UNNUMBERED,
1266 .procname = "highmem_is_dirtyable",
1267 .data = &vm_highmem_is_dirtyable,
1268 .maxlen = sizeof(vm_highmem_is_dirtyable),
1270 .proc_handler = &proc_dointvec_minmax,
1271 .strategy = &sysctl_intvec,
1277 * NOTE: do not add new entries to this table unless you have read
1278 * Documentation/sysctl/ctl_unnumbered.txt
1283 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1284 static struct ctl_table binfmt_misc_table[] = {
1289 static struct ctl_table fs_table[] = {
1291 .ctl_name = FS_NRINODE,
1292 .procname = "inode-nr",
1293 .data = &inodes_stat,
1294 .maxlen = 2*sizeof(int),
1296 .proc_handler = &proc_dointvec,
1299 .ctl_name = FS_STATINODE,
1300 .procname = "inode-state",
1301 .data = &inodes_stat,
1302 .maxlen = 7*sizeof(int),
1304 .proc_handler = &proc_dointvec,
1307 .procname = "file-nr",
1308 .data = &files_stat,
1309 .maxlen = 3*sizeof(int),
1311 .proc_handler = &proc_nr_files,
1314 .ctl_name = FS_MAXFILE,
1315 .procname = "file-max",
1316 .data = &files_stat.max_files,
1317 .maxlen = sizeof(int),
1319 .proc_handler = &proc_dointvec,
1322 .ctl_name = CTL_UNNUMBERED,
1323 .procname = "nr_open",
1324 .data = &sysctl_nr_open,
1325 .maxlen = sizeof(int),
1327 .proc_handler = &proc_dointvec_minmax,
1328 .extra1 = &sysctl_nr_open_min,
1329 .extra2 = &sysctl_nr_open_max,
1332 .ctl_name = FS_DENTRY,
1333 .procname = "dentry-state",
1334 .data = &dentry_stat,
1335 .maxlen = 6*sizeof(int),
1337 .proc_handler = &proc_dointvec,
1340 .ctl_name = FS_OVERFLOWUID,
1341 .procname = "overflowuid",
1342 .data = &fs_overflowuid,
1343 .maxlen = sizeof(int),
1345 .proc_handler = &proc_dointvec_minmax,
1346 .strategy = &sysctl_intvec,
1347 .extra1 = &minolduid,
1348 .extra2 = &maxolduid,
1351 .ctl_name = FS_OVERFLOWGID,
1352 .procname = "overflowgid",
1353 .data = &fs_overflowgid,
1354 .maxlen = sizeof(int),
1356 .proc_handler = &proc_dointvec_minmax,
1357 .strategy = &sysctl_intvec,
1358 .extra1 = &minolduid,
1359 .extra2 = &maxolduid,
1361 #ifdef CONFIG_FILE_LOCKING
1363 .ctl_name = FS_LEASES,
1364 .procname = "leases-enable",
1365 .data = &leases_enable,
1366 .maxlen = sizeof(int),
1368 .proc_handler = &proc_dointvec,
1371 #ifdef CONFIG_DNOTIFY
1373 .ctl_name = FS_DIR_NOTIFY,
1374 .procname = "dir-notify-enable",
1375 .data = &dir_notify_enable,
1376 .maxlen = sizeof(int),
1378 .proc_handler = &proc_dointvec,
1382 #ifdef CONFIG_FILE_LOCKING
1384 .ctl_name = FS_LEASE_TIME,
1385 .procname = "lease-break-time",
1386 .data = &lease_break_time,
1387 .maxlen = sizeof(int),
1389 .proc_handler = &proc_dointvec_minmax,
1390 .strategy = &sysctl_intvec,
1397 .procname = "aio-nr",
1399 .maxlen = sizeof(aio_nr),
1401 .proc_handler = &proc_doulongvec_minmax,
1404 .procname = "aio-max-nr",
1405 .data = &aio_max_nr,
1406 .maxlen = sizeof(aio_max_nr),
1408 .proc_handler = &proc_doulongvec_minmax,
1410 #endif /* CONFIG_AIO */
1411 #ifdef CONFIG_INOTIFY_USER
1413 .ctl_name = FS_INOTIFY,
1414 .procname = "inotify",
1416 .child = inotify_table,
1421 .procname = "epoll",
1423 .child = epoll_table,
1428 .ctl_name = KERN_SETUID_DUMPABLE,
1429 .procname = "suid_dumpable",
1430 .data = &suid_dumpable,
1431 .maxlen = sizeof(int),
1433 .proc_handler = &proc_dointvec,
1435 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1437 .ctl_name = CTL_UNNUMBERED,
1438 .procname = "binfmt_misc",
1440 .child = binfmt_misc_table,
1444 * NOTE: do not add new entries to this table unless you have read
1445 * Documentation/sysctl/ctl_unnumbered.txt
1450 static struct ctl_table debug_table[] = {
1451 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1453 .ctl_name = CTL_UNNUMBERED,
1454 .procname = "exception-trace",
1455 .data = &show_unhandled_signals,
1456 .maxlen = sizeof(int),
1458 .proc_handler = proc_dointvec
1464 static struct ctl_table dev_table[] = {
1468 static DEFINE_SPINLOCK(sysctl_lock);
1470 /* called under sysctl_lock */
1471 static int use_table(struct ctl_table_header *p)
1473 if (unlikely(p->unregistering))
1479 /* called under sysctl_lock */
1480 static void unuse_table(struct ctl_table_header *p)
1483 if (unlikely(p->unregistering))
1484 complete(p->unregistering);
1487 /* called under sysctl_lock, will reacquire if has to wait */
1488 static void start_unregistering(struct ctl_table_header *p)
1491 * if p->used is 0, nobody will ever touch that entry again;
1492 * we'll eliminate all paths to it before dropping sysctl_lock
1494 if (unlikely(p->used)) {
1495 struct completion wait;
1496 init_completion(&wait);
1497 p->unregistering = &wait;
1498 spin_unlock(&sysctl_lock);
1499 wait_for_completion(&wait);
1500 spin_lock(&sysctl_lock);
1502 /* anything non-NULL; we'll never dereference it */
1503 p->unregistering = ERR_PTR(-EINVAL);
1506 * do not remove from the list until nobody holds it; walking the
1507 * list in do_sysctl() relies on that.
1509 list_del_init(&p->ctl_entry);
1512 void sysctl_head_get(struct ctl_table_header *head)
1514 spin_lock(&sysctl_lock);
1516 spin_unlock(&sysctl_lock);
1519 void sysctl_head_put(struct ctl_table_header *head)
1521 spin_lock(&sysctl_lock);
1524 spin_unlock(&sysctl_lock);
1527 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1531 spin_lock(&sysctl_lock);
1532 if (!use_table(head))
1533 head = ERR_PTR(-ENOENT);
1534 spin_unlock(&sysctl_lock);
1538 void sysctl_head_finish(struct ctl_table_header *head)
1542 spin_lock(&sysctl_lock);
1544 spin_unlock(&sysctl_lock);
1547 static struct ctl_table_set *
1548 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1550 struct ctl_table_set *set = &root->default_set;
1552 set = root->lookup(root, namespaces);
1556 static struct list_head *
1557 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1559 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1563 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1564 struct ctl_table_header *prev)
1566 struct ctl_table_root *root;
1567 struct list_head *header_list;
1568 struct ctl_table_header *head;
1569 struct list_head *tmp;
1571 spin_lock(&sysctl_lock);
1574 tmp = &prev->ctl_entry;
1578 tmp = &root_table_header.ctl_entry;
1580 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1582 if (!use_table(head))
1584 spin_unlock(&sysctl_lock);
1589 header_list = lookup_header_list(root, namespaces);
1590 if (tmp != header_list)
1594 root = list_entry(root->root_list.next,
1595 struct ctl_table_root, root_list);
1596 if (root == &sysctl_table_root)
1598 header_list = lookup_header_list(root, namespaces);
1599 } while (list_empty(header_list));
1600 tmp = header_list->next;
1603 spin_unlock(&sysctl_lock);
1607 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1609 return __sysctl_head_next(current->nsproxy, prev);
1612 void register_sysctl_root(struct ctl_table_root *root)
1614 spin_lock(&sysctl_lock);
1615 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1616 spin_unlock(&sysctl_lock);
1619 #ifdef CONFIG_SYSCTL_SYSCALL
1620 /* Perform the actual read/write of a sysctl table entry. */
1621 static int do_sysctl_strategy(struct ctl_table_root *root,
1622 struct ctl_table *table,
1623 void __user *oldval, size_t __user *oldlenp,
1624 void __user *newval, size_t newlen)
1632 if (sysctl_perm(root, table, op))
1635 if (table->strategy) {
1636 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1643 /* If there is no strategy routine, or if the strategy returns
1644 * zero, proceed with automatic r/w */
1645 if (table->data && table->maxlen) {
1646 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1653 static int parse_table(int __user *name, int nlen,
1654 void __user *oldval, size_t __user *oldlenp,
1655 void __user *newval, size_t newlen,
1656 struct ctl_table_root *root,
1657 struct ctl_table *table)
1663 if (get_user(n, name))
1665 for ( ; table->ctl_name || table->procname; table++) {
1666 if (!table->ctl_name)
1668 if (n == table->ctl_name) {
1671 if (sysctl_perm(root, table, MAY_EXEC))
1675 table = table->child;
1678 error = do_sysctl_strategy(root, table,
1687 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1688 void __user *newval, size_t newlen)
1690 struct ctl_table_header *head;
1691 int error = -ENOTDIR;
1693 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1697 if (!oldlenp || get_user(old_len, oldlenp))
1701 for (head = sysctl_head_next(NULL); head;
1702 head = sysctl_head_next(head)) {
1703 error = parse_table(name, nlen, oldval, oldlenp,
1705 head->root, head->ctl_table);
1706 if (error != -ENOTDIR) {
1707 sysctl_head_finish(head);
1714 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1716 struct __sysctl_args tmp;
1719 if (copy_from_user(&tmp, args, sizeof(tmp)))
1722 error = deprecated_sysctl_warning(&tmp);
1727 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1728 tmp.newval, tmp.newlen);
1733 #endif /* CONFIG_SYSCTL_SYSCALL */
1736 * sysctl_perm does NOT grant the superuser all rights automatically, because
1737 * some sysctl variables are readonly even to root.
1740 static int test_perm(int mode, int op)
1742 if (!current_euid())
1744 else if (in_egroup_p(0))
1746 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1751 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1756 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1760 if (root->permissions)
1761 mode = root->permissions(root, current->nsproxy, table);
1765 return test_perm(mode, op);
1768 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1770 for (; table->ctl_name || table->procname; table++) {
1771 table->parent = parent;
1773 sysctl_set_parent(table, table->child);
1777 static __init int sysctl_init(void)
1779 sysctl_set_parent(NULL, root_table);
1780 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1783 err = sysctl_check_table(current->nsproxy, root_table);
1789 core_initcall(sysctl_init);
1791 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1792 struct ctl_table *table)
1794 struct ctl_table *p;
1795 const char *s = branch->procname;
1797 /* branch should have named subdirectory as its first element */
1798 if (!s || !branch->child)
1801 /* ... and nothing else */
1802 if (branch[1].procname || branch[1].ctl_name)
1805 /* table should contain subdirectory with the same name */
1806 for (p = table; p->procname || p->ctl_name; p++) {
1809 if (p->procname && strcmp(p->procname, s) == 0)
1815 /* see if attaching q to p would be an improvement */
1816 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1818 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1819 struct ctl_table *next;
1821 int not_in_parent = !p->attached_by;
1823 while ((next = is_branch_in(by, to)) != NULL) {
1824 if (by == q->attached_by)
1826 if (to == p->attached_by)
1832 if (is_better && not_in_parent) {
1833 q->attached_by = by;
1834 q->attached_to = to;
1840 * __register_sysctl_paths - register a sysctl hierarchy
1841 * @root: List of sysctl headers to register on
1842 * @namespaces: Data to compute which lists of sysctl entries are visible
1843 * @path: The path to the directory the sysctl table is in.
1844 * @table: the top-level table structure
1846 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1847 * array. A completely 0 filled entry terminates the table.
1849 * The members of the &struct ctl_table structure are used as follows:
1851 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1852 * must be unique within that level of sysctl
1854 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1855 * enter a sysctl file
1857 * data - a pointer to data for use by proc_handler
1859 * maxlen - the maximum size in bytes of the data
1861 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1863 * child - a pointer to the child sysctl table if this entry is a directory, or
1866 * proc_handler - the text handler routine (described below)
1868 * strategy - the strategy routine (described below)
1870 * de - for internal use by the sysctl routines
1872 * extra1, extra2 - extra pointers usable by the proc handler routines
1874 * Leaf nodes in the sysctl tree will be represented by a single file
1875 * under /proc; non-leaf nodes will be represented by directories.
1877 * sysctl(2) can automatically manage read and write requests through
1878 * the sysctl table. The data and maxlen fields of the ctl_table
1879 * struct enable minimal validation of the values being written to be
1880 * performed, and the mode field allows minimal authentication.
1882 * More sophisticated management can be enabled by the provision of a
1883 * strategy routine with the table entry. This will be called before
1884 * any automatic read or write of the data is performed.
1886 * The strategy routine may return
1888 * < 0 - Error occurred (error is passed to user process)
1890 * 0 - OK - proceed with automatic read or write.
1892 * > 0 - OK - read or write has been done by the strategy routine, so
1893 * return immediately.
1895 * There must be a proc_handler routine for any terminal nodes
1896 * mirrored under /proc/sys (non-terminals are handled by a built-in
1897 * directory handler). Several default handlers are available to
1898 * cover common cases -
1900 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1901 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1902 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1904 * It is the handler's job to read the input buffer from user memory
1905 * and process it. The handler should return 0 on success.
1907 * This routine returns %NULL on a failure to register, and a pointer
1908 * to the table header on success.
1910 struct ctl_table_header *__register_sysctl_paths(
1911 struct ctl_table_root *root,
1912 struct nsproxy *namespaces,
1913 const struct ctl_path *path, struct ctl_table *table)
1915 struct ctl_table_header *header;
1916 struct ctl_table *new, **prevp;
1917 unsigned int n, npath;
1918 struct ctl_table_set *set;
1920 /* Count the path components */
1921 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1925 * For each path component, allocate a 2-element ctl_table array.
1926 * The first array element will be filled with the sysctl entry
1927 * for this, the second will be the sentinel (ctl_name == 0).
1929 * We allocate everything in one go so that we don't have to
1930 * worry about freeing additional memory in unregister_sysctl_table.
1932 header = kzalloc(sizeof(struct ctl_table_header) +
1933 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1937 new = (struct ctl_table *) (header + 1);
1939 /* Now connect the dots */
1940 prevp = &header->ctl_table;
1941 for (n = 0; n < npath; ++n, ++path) {
1942 /* Copy the procname */
1943 new->procname = path->procname;
1944 new->ctl_name = path->ctl_name;
1948 prevp = &new->child;
1953 header->ctl_table_arg = table;
1955 INIT_LIST_HEAD(&header->ctl_entry);
1957 header->unregistering = NULL;
1958 header->root = root;
1959 sysctl_set_parent(NULL, header->ctl_table);
1961 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1962 if (sysctl_check_table(namespaces, header->ctl_table)) {
1967 spin_lock(&sysctl_lock);
1968 header->set = lookup_header_set(root, namespaces);
1969 header->attached_by = header->ctl_table;
1970 header->attached_to = root_table;
1971 header->parent = &root_table_header;
1972 for (set = header->set; set; set = set->parent) {
1973 struct ctl_table_header *p;
1974 list_for_each_entry(p, &set->list, ctl_entry) {
1975 if (p->unregistering)
1977 try_attach(p, header);
1980 header->parent->count++;
1981 list_add_tail(&header->ctl_entry, &header->set->list);
1982 spin_unlock(&sysctl_lock);
1988 * register_sysctl_table_path - register a sysctl table hierarchy
1989 * @path: The path to the directory the sysctl table is in.
1990 * @table: the top-level table structure
1992 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1993 * array. A completely 0 filled entry terminates the table.
1995 * See __register_sysctl_paths for more details.
1997 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1998 struct ctl_table *table)
2000 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2005 * register_sysctl_table - register a sysctl table hierarchy
2006 * @table: the top-level table structure
2008 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2009 * array. A completely 0 filled entry terminates the table.
2011 * See register_sysctl_paths for more details.
2013 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2015 static const struct ctl_path null_path[] = { {} };
2017 return register_sysctl_paths(null_path, table);
2021 * unregister_sysctl_table - unregister a sysctl table hierarchy
2022 * @header: the header returned from register_sysctl_table
2024 * Unregisters the sysctl table and all children. proc entries may not
2025 * actually be removed until they are no longer used by anyone.
2027 void unregister_sysctl_table(struct ctl_table_header * header)
2034 spin_lock(&sysctl_lock);
2035 start_unregistering(header);
2036 if (!--header->parent->count) {
2038 kfree(header->parent);
2040 if (!--header->count)
2042 spin_unlock(&sysctl_lock);
2045 int sysctl_is_seen(struct ctl_table_header *p)
2047 struct ctl_table_set *set = p->set;
2049 spin_lock(&sysctl_lock);
2050 if (p->unregistering)
2052 else if (!set->is_seen)
2055 res = set->is_seen(set);
2056 spin_unlock(&sysctl_lock);
2060 void setup_sysctl_set(struct ctl_table_set *p,
2061 struct ctl_table_set *parent,
2062 int (*is_seen)(struct ctl_table_set *))
2064 INIT_LIST_HEAD(&p->list);
2065 p->parent = parent ? parent : &sysctl_table_root.default_set;
2066 p->is_seen = is_seen;
2069 #else /* !CONFIG_SYSCTL */
2070 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2075 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2076 struct ctl_table *table)
2081 void unregister_sysctl_table(struct ctl_table_header * table)
2085 void setup_sysctl_set(struct ctl_table_set *p,
2086 struct ctl_table_set *parent,
2087 int (*is_seen)(struct ctl_table_set *))
2091 void sysctl_head_put(struct ctl_table_header *head)
2095 #endif /* CONFIG_SYSCTL */
2101 #ifdef CONFIG_PROC_SYSCTL
2103 static int _proc_do_string(void* data, int maxlen, int write,
2104 struct file *filp, void __user *buffer,
2105 size_t *lenp, loff_t *ppos)
2111 if (!data || !maxlen || !*lenp) {
2119 while (len < *lenp) {
2120 if (get_user(c, p++))
2122 if (c == 0 || c == '\n')
2128 if(copy_from_user(data, buffer, len))
2130 ((char *) data)[len] = 0;
2148 if(copy_to_user(buffer, data, len))
2151 if(put_user('\n', ((char __user *) buffer) + len))
2162 * proc_dostring - read a string sysctl
2163 * @table: the sysctl table
2164 * @write: %TRUE if this is a write to the sysctl file
2165 * @filp: the file structure
2166 * @buffer: the user buffer
2167 * @lenp: the size of the user buffer
2168 * @ppos: file position
2170 * Reads/writes a string from/to the user buffer. If the kernel
2171 * buffer provided is not large enough to hold the string, the
2172 * string is truncated. The copied string is %NULL-terminated.
2173 * If the string is being read by the user process, it is copied
2174 * and a newline '\n' is added. It is truncated if the buffer is
2177 * Returns 0 on success.
2179 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2180 void __user *buffer, size_t *lenp, loff_t *ppos)
2182 return _proc_do_string(table->data, table->maxlen, write, filp,
2183 buffer, lenp, ppos);
2187 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2189 int write, void *data)
2192 *valp = *negp ? -*lvalp : *lvalp;
2197 *lvalp = (unsigned long)-val;
2200 *lvalp = (unsigned long)val;
2206 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2207 int write, struct file *filp, void __user *buffer,
2208 size_t *lenp, loff_t *ppos,
2209 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2210 int write, void *data),
2213 #define TMPBUFLEN 21
2214 int *i, vleft, first=1, neg, val;
2218 char buf[TMPBUFLEN], *p;
2219 char __user *s = buffer;
2221 if (!tbl_data || !table->maxlen || !*lenp ||
2222 (*ppos && !write)) {
2227 i = (int *) tbl_data;
2228 vleft = table->maxlen / sizeof(*i);
2232 conv = do_proc_dointvec_conv;
2234 for (; left && vleft--; i++, first=0) {
2249 if (len > sizeof(buf) - 1)
2250 len = sizeof(buf) - 1;
2251 if (copy_from_user(buf, s, len))
2255 if (*p == '-' && left > 1) {
2259 if (*p < '0' || *p > '9')
2262 lval = simple_strtoul(p, &p, 0);
2265 if ((len < left) && *p && !isspace(*p))
2272 if (conv(&neg, &lval, i, 1, data))
2279 if (conv(&neg, &lval, i, 0, data))
2282 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2286 if(copy_to_user(s, buf, len))
2293 if (!write && !first && left) {
2294 if(put_user('\n', s))
2301 if (get_user(c, s++))
2316 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2317 void __user *buffer, size_t *lenp, loff_t *ppos,
2318 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2319 int write, void *data),
2322 return __do_proc_dointvec(table->data, table, write, filp,
2323 buffer, lenp, ppos, conv, data);
2327 * proc_dointvec - read a vector of integers
2328 * @table: the sysctl table
2329 * @write: %TRUE if this is a write to the sysctl file
2330 * @filp: the file structure
2331 * @buffer: the user buffer
2332 * @lenp: the size of the user buffer
2333 * @ppos: file position
2335 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2336 * values from/to the user buffer, treated as an ASCII string.
2338 * Returns 0 on success.
2340 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2341 void __user *buffer, size_t *lenp, loff_t *ppos)
2343 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2348 * Taint values can only be increased
2349 * This means we can safely use a temporary.
2351 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2352 void __user *buffer, size_t *lenp, loff_t *ppos)
2355 unsigned long tmptaint = get_taint();
2358 if (write && !capable(CAP_SYS_ADMIN))
2363 err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2369 * Poor man's atomic or. Not worth adding a primitive
2370 * to everyone's atomic.h for this
2373 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2374 if ((tmptaint >> i) & 1)
2382 struct do_proc_dointvec_minmax_conv_param {
2387 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2389 int write, void *data)
2391 struct do_proc_dointvec_minmax_conv_param *param = data;
2393 int val = *negp ? -*lvalp : *lvalp;
2394 if ((param->min && *param->min > val) ||
2395 (param->max && *param->max < val))
2402 *lvalp = (unsigned long)-val;
2405 *lvalp = (unsigned long)val;
2412 * proc_dointvec_minmax - read a vector of integers with min/max values
2413 * @table: the sysctl table
2414 * @write: %TRUE if this is a write to the sysctl file
2415 * @filp: the file structure
2416 * @buffer: the user buffer
2417 * @lenp: the size of the user buffer
2418 * @ppos: file position
2420 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2421 * values from/to the user buffer, treated as an ASCII string.
2423 * This routine will ensure the values are within the range specified by
2424 * table->extra1 (min) and table->extra2 (max).
2426 * Returns 0 on success.
2428 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2429 void __user *buffer, size_t *lenp, loff_t *ppos)
2431 struct do_proc_dointvec_minmax_conv_param param = {
2432 .min = (int *) table->extra1,
2433 .max = (int *) table->extra2,
2435 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2436 do_proc_dointvec_minmax_conv, ¶m);
2439 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2441 void __user *buffer,
2442 size_t *lenp, loff_t *ppos,
2443 unsigned long convmul,
2444 unsigned long convdiv)
2446 #define TMPBUFLEN 21
2447 unsigned long *i, *min, *max, val;
2448 int vleft, first=1, neg;
2450 char buf[TMPBUFLEN], *p;
2451 char __user *s = buffer;
2453 if (!data || !table->maxlen || !*lenp ||
2454 (*ppos && !write)) {
2459 i = (unsigned long *) data;
2460 min = (unsigned long *) table->extra1;
2461 max = (unsigned long *) table->extra2;
2462 vleft = table->maxlen / sizeof(unsigned long);
2465 for (; left && vleft--; i++, min++, max++, first=0) {
2480 if (len > TMPBUFLEN-1)
2482 if (copy_from_user(buf, s, len))
2486 if (*p == '-' && left > 1) {
2490 if (*p < '0' || *p > '9')
2492 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2494 if ((len < left) && *p && !isspace(*p))
2503 if ((min && val < *min) || (max && val > *max))
2510 sprintf(p, "%lu", convdiv * (*i) / convmul);
2514 if(copy_to_user(s, buf, len))
2521 if (!write && !first && left) {
2522 if(put_user('\n', s))
2529 if (get_user(c, s++))
2544 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2546 void __user *buffer,
2547 size_t *lenp, loff_t *ppos,
2548 unsigned long convmul,
2549 unsigned long convdiv)
2551 return __do_proc_doulongvec_minmax(table->data, table, write,
2552 filp, buffer, lenp, ppos, convmul, convdiv);
2556 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2557 * @table: the sysctl table
2558 * @write: %TRUE if this is a write to the sysctl file
2559 * @filp: the file structure
2560 * @buffer: the user buffer
2561 * @lenp: the size of the user buffer
2562 * @ppos: file position
2564 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2565 * values from/to the user buffer, treated as an ASCII string.
2567 * This routine will ensure the values are within the range specified by
2568 * table->extra1 (min) and table->extra2 (max).
2570 * Returns 0 on success.
2572 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2573 void __user *buffer, size_t *lenp, loff_t *ppos)
2575 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2579 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2580 * @table: the sysctl table
2581 * @write: %TRUE if this is a write to the sysctl file
2582 * @filp: the file structure
2583 * @buffer: the user buffer
2584 * @lenp: the size of the user buffer
2585 * @ppos: file position
2587 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2588 * values from/to the user buffer, treated as an ASCII string. The values
2589 * are treated as milliseconds, and converted to jiffies when they are stored.
2591 * This routine will ensure the values are within the range specified by
2592 * table->extra1 (min) and table->extra2 (max).
2594 * Returns 0 on success.
2596 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2598 void __user *buffer,
2599 size_t *lenp, loff_t *ppos)
2601 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2602 lenp, ppos, HZ, 1000l);
2606 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2608 int write, void *data)
2611 if (*lvalp > LONG_MAX / HZ)
2613 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2619 lval = (unsigned long)-val;
2622 lval = (unsigned long)val;
2629 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2631 int write, void *data)
2634 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2636 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2642 lval = (unsigned long)-val;
2645 lval = (unsigned long)val;
2647 *lvalp = jiffies_to_clock_t(lval);
2652 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2654 int write, void *data)
2657 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2663 lval = (unsigned long)-val;
2666 lval = (unsigned long)val;
2668 *lvalp = jiffies_to_msecs(lval);
2674 * proc_dointvec_jiffies - read a vector of integers as seconds
2675 * @table: the sysctl table
2676 * @write: %TRUE if this is a write to the sysctl file
2677 * @filp: the file structure
2678 * @buffer: the user buffer
2679 * @lenp: the size of the user buffer
2680 * @ppos: file position
2682 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2683 * values from/to the user buffer, treated as an ASCII string.
2684 * The values read are assumed to be in seconds, and are converted into
2687 * Returns 0 on success.
2689 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2690 void __user *buffer, size_t *lenp, loff_t *ppos)
2692 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2693 do_proc_dointvec_jiffies_conv,NULL);
2697 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2698 * @table: the sysctl table
2699 * @write: %TRUE if this is a write to the sysctl file
2700 * @filp: the file structure
2701 * @buffer: the user buffer
2702 * @lenp: the size of the user buffer
2703 * @ppos: pointer to the file position
2705 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2706 * values from/to the user buffer, treated as an ASCII string.
2707 * The values read are assumed to be in 1/USER_HZ seconds, and
2708 * are converted into jiffies.
2710 * Returns 0 on success.
2712 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2713 void __user *buffer, size_t *lenp, loff_t *ppos)
2715 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2716 do_proc_dointvec_userhz_jiffies_conv,NULL);
2720 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2721 * @table: the sysctl table
2722 * @write: %TRUE if this is a write to the sysctl file
2723 * @filp: the file structure
2724 * @buffer: the user buffer
2725 * @lenp: the size of the user buffer
2726 * @ppos: file position
2727 * @ppos: the current position in the file
2729 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2730 * values from/to the user buffer, treated as an ASCII string.
2731 * The values read are assumed to be in 1/1000 seconds, and
2732 * are converted into jiffies.
2734 * Returns 0 on success.
2736 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2737 void __user *buffer, size_t *lenp, loff_t *ppos)
2739 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2740 do_proc_dointvec_ms_jiffies_conv, NULL);
2743 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2744 void __user *buffer, size_t *lenp, loff_t *ppos)
2746 struct pid *new_pid;
2750 tmp = pid_vnr(cad_pid);
2752 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2753 lenp, ppos, NULL, NULL);
2757 new_pid = find_get_pid(tmp);
2761 put_pid(xchg(&cad_pid, new_pid));
2765 #else /* CONFIG_PROC_FS */
2767 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2768 void __user *buffer, size_t *lenp, loff_t *ppos)
2773 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2774 void __user *buffer, size_t *lenp, loff_t *ppos)
2779 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2780 void __user *buffer, size_t *lenp, loff_t *ppos)
2785 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2786 void __user *buffer, size_t *lenp, loff_t *ppos)
2791 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2792 void __user *buffer, size_t *lenp, loff_t *ppos)
2797 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2798 void __user *buffer, size_t *lenp, loff_t *ppos)
2803 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2804 void __user *buffer, size_t *lenp, loff_t *ppos)
2809 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2811 void __user *buffer,
2812 size_t *lenp, loff_t *ppos)
2818 #endif /* CONFIG_PROC_FS */
2821 #ifdef CONFIG_SYSCTL_SYSCALL
2823 * General sysctl support routines
2826 /* The generic sysctl data routine (used if no strategy routine supplied) */
2827 int sysctl_data(struct ctl_table *table,
2828 void __user *oldval, size_t __user *oldlenp,
2829 void __user *newval, size_t newlen)
2833 /* Get out of I don't have a variable */
2834 if (!table->data || !table->maxlen)
2837 if (oldval && oldlenp) {
2838 if (get_user(len, oldlenp))
2841 if (len > table->maxlen)
2842 len = table->maxlen;
2843 if (copy_to_user(oldval, table->data, len))
2845 if (put_user(len, oldlenp))
2850 if (newval && newlen) {
2851 if (newlen > table->maxlen)
2852 newlen = table->maxlen;
2854 if (copy_from_user(table->data, newval, newlen))
2860 /* The generic string strategy routine: */
2861 int sysctl_string(struct ctl_table *table,
2862 void __user *oldval, size_t __user *oldlenp,
2863 void __user *newval, size_t newlen)
2865 if (!table->data || !table->maxlen)
2868 if (oldval && oldlenp) {
2870 if (get_user(bufsize, oldlenp))
2873 size_t len = strlen(table->data), copied;
2875 /* This shouldn't trigger for a well-formed sysctl */
2876 if (len > table->maxlen)
2877 len = table->maxlen;
2879 /* Copy up to a max of bufsize-1 bytes of the string */
2880 copied = (len >= bufsize) ? bufsize - 1 : len;
2882 if (copy_to_user(oldval, table->data, copied) ||
2883 put_user(0, (char __user *)(oldval + copied)))
2885 if (put_user(len, oldlenp))
2889 if (newval && newlen) {
2890 size_t len = newlen;
2891 if (len > table->maxlen)
2892 len = table->maxlen;
2893 if(copy_from_user(table->data, newval, len))
2895 if (len == table->maxlen)
2897 ((char *) table->data)[len] = 0;
2903 * This function makes sure that all of the integers in the vector
2904 * are between the minimum and maximum values given in the arrays
2905 * table->extra1 and table->extra2, respectively.
2907 int sysctl_intvec(struct ctl_table *table,
2908 void __user *oldval, size_t __user *oldlenp,
2909 void __user *newval, size_t newlen)
2912 if (newval && newlen) {
2913 int __user *vec = (int __user *) newval;
2914 int *min = (int *) table->extra1;
2915 int *max = (int *) table->extra2;
2919 if (newlen % sizeof(int) != 0)
2922 if (!table->extra1 && !table->extra2)
2925 if (newlen > table->maxlen)
2926 newlen = table->maxlen;
2927 length = newlen / sizeof(int);
2929 for (i = 0; i < length; i++) {
2931 if (get_user(value, vec + i))
2933 if (min && value < min[i])
2935 if (max && value > max[i])
2942 /* Strategy function to convert jiffies to seconds */
2943 int sysctl_jiffies(struct ctl_table *table,
2944 void __user *oldval, size_t __user *oldlenp,
2945 void __user *newval, size_t newlen)
2947 if (oldval && oldlenp) {
2950 if (get_user(olen, oldlenp))
2955 if (olen < sizeof(int))
2958 val = *(int *)(table->data) / HZ;
2959 if (put_user(val, (int __user *)oldval))
2961 if (put_user(sizeof(int), oldlenp))
2965 if (newval && newlen) {
2967 if (newlen != sizeof(int))
2969 if (get_user(new, (int __user *)newval))
2971 *(int *)(table->data) = new*HZ;
2976 /* Strategy function to convert jiffies to seconds */
2977 int sysctl_ms_jiffies(struct ctl_table *table,
2978 void __user *oldval, size_t __user *oldlenp,
2979 void __user *newval, size_t newlen)
2981 if (oldval && oldlenp) {
2984 if (get_user(olen, oldlenp))
2989 if (olen < sizeof(int))
2992 val = jiffies_to_msecs(*(int *)(table->data));
2993 if (put_user(val, (int __user *)oldval))
2995 if (put_user(sizeof(int), oldlenp))
2999 if (newval && newlen) {
3001 if (newlen != sizeof(int))
3003 if (get_user(new, (int __user *)newval))
3005 *(int *)(table->data) = msecs_to_jiffies(new);
3012 #else /* CONFIG_SYSCTL_SYSCALL */
3015 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3017 struct __sysctl_args tmp;
3020 if (copy_from_user(&tmp, args, sizeof(tmp)))
3023 error = deprecated_sysctl_warning(&tmp);
3025 /* If no error reading the parameters then just -ENOSYS ... */
3032 int sysctl_data(struct ctl_table *table,
3033 void __user *oldval, size_t __user *oldlenp,
3034 void __user *newval, size_t newlen)
3039 int sysctl_string(struct ctl_table *table,
3040 void __user *oldval, size_t __user *oldlenp,
3041 void __user *newval, size_t newlen)
3046 int sysctl_intvec(struct ctl_table *table,
3047 void __user *oldval, size_t __user *oldlenp,
3048 void __user *newval, size_t newlen)
3053 int sysctl_jiffies(struct ctl_table *table,
3054 void __user *oldval, size_t __user *oldlenp,
3055 void __user *newval, size_t newlen)
3060 int sysctl_ms_jiffies(struct ctl_table *table,
3061 void __user *oldval, size_t __user *oldlenp,
3062 void __user *newval, size_t newlen)
3067 #endif /* CONFIG_SYSCTL_SYSCALL */
3069 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3071 static int msg_count;
3072 int name[CTL_MAXNAME];
3075 /* Check args->nlen. */
3076 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3079 /* Read in the sysctl name for better debug message logging */
3080 for (i = 0; i < args->nlen; i++)
3081 if (get_user(name[i], args->name + i))
3084 /* Ignore accesses to kernel.version */
3085 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3088 if (msg_count < 5) {
3091 "warning: process `%s' used the deprecated sysctl "
3092 "system call with ", current->comm);
3093 for (i = 0; i < args->nlen; i++)
3094 printk("%d.", name[i]);
3101 * No sense putting this after each symbol definition, twice,
3102 * exception granted :-)
3104 EXPORT_SYMBOL(proc_dointvec);
3105 EXPORT_SYMBOL(proc_dointvec_jiffies);
3106 EXPORT_SYMBOL(proc_dointvec_minmax);
3107 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3108 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3109 EXPORT_SYMBOL(proc_dostring);
3110 EXPORT_SYMBOL(proc_doulongvec_minmax);
3111 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3112 EXPORT_SYMBOL(register_sysctl_table);
3113 EXPORT_SYMBOL(register_sysctl_paths);
3114 EXPORT_SYMBOL(sysctl_intvec);
3115 EXPORT_SYMBOL(sysctl_jiffies);
3116 EXPORT_SYMBOL(sysctl_ms_jiffies);
3117 EXPORT_SYMBOL(sysctl_string);
3118 EXPORT_SYMBOL(sysctl_data);
3119 EXPORT_SYMBOL(unregister_sysctl_table);