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>
51 #include <linux/slow-work.h>
53 #include <asm/uaccess.h>
54 #include <asm/processor.h>
58 #include <asm/stacktrace.h>
62 static int deprecated_sysctl_warning(struct __sysctl_args *args);
64 #if defined(CONFIG_SYSCTL)
66 /* External variables not in a header file. */
68 extern int print_fatal_signals;
69 extern int sysctl_overcommit_memory;
70 extern int sysctl_overcommit_ratio;
71 extern int sysctl_panic_on_oom;
72 extern int sysctl_oom_kill_allocating_task;
73 extern int sysctl_oom_dump_tasks;
74 extern int max_threads;
75 extern int core_uses_pid;
76 extern int suid_dumpable;
77 extern char core_pattern[];
79 extern int min_free_kbytes;
80 extern int pid_max_min, pid_max_max;
81 extern int sysctl_drop_caches;
82 extern int percpu_pagelist_fraction;
83 extern int compat_log;
84 extern int latencytop_enabled;
85 extern int sysctl_nr_open_min, sysctl_nr_open_max;
87 extern int sysctl_nr_trim_pages;
89 #ifdef CONFIG_RCU_TORTURE_TEST
90 extern int rcutorture_runnable;
91 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
93 /* Constants used for minimum and maximum */
94 #ifdef CONFIG_DETECT_SOFTLOCKUP
95 static int sixty = 60;
96 static int neg_one = -1;
100 static int __maybe_unused one = 1;
101 static int __maybe_unused two = 2;
102 static unsigned long one_ul = 1;
103 static int one_hundred = 100;
105 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
106 static int maxolduid = 65535;
107 static int minolduid;
108 static int min_percpu_pagelist_fract = 8;
110 static int ngroups_max = NGROUPS_MAX;
112 #ifdef CONFIG_MODULES
113 extern char modprobe_path[];
115 #ifdef CONFIG_CHR_DEV_SG
116 extern int sg_big_buff;
120 #include <asm/system.h>
123 #ifdef CONFIG_SPARC64
124 extern int sysctl_tsb_ratio;
128 extern int pwrsw_enabled;
129 extern int unaligned_enabled;
133 #ifdef CONFIG_MATHEMU
134 extern int sysctl_ieee_emulation_warnings;
136 extern int sysctl_userprocess_debug;
137 extern int spin_retry;
140 #ifdef CONFIG_BSD_PROCESS_ACCT
141 extern int acct_parm[];
145 extern int no_unaligned_warning;
146 extern int unaligned_dump_stack;
149 #ifdef CONFIG_RT_MUTEXES
150 extern int max_lock_depth;
153 #ifdef CONFIG_PROC_SYSCTL
154 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
155 void __user *buffer, size_t *lenp, loff_t *ppos);
156 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
157 void __user *buffer, size_t *lenp, loff_t *ppos);
160 static struct ctl_table root_table[];
161 static struct ctl_table_root sysctl_table_root;
162 static struct ctl_table_header root_table_header = {
164 .ctl_table = root_table,
165 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
166 .root = &sysctl_table_root,
167 .set = &sysctl_table_root.default_set,
169 static struct ctl_table_root sysctl_table_root = {
170 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
171 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
174 static struct ctl_table kern_table[];
175 static struct ctl_table vm_table[];
176 static struct ctl_table fs_table[];
177 static struct ctl_table debug_table[];
178 static struct ctl_table dev_table[];
179 extern struct ctl_table random_table[];
180 #ifdef CONFIG_INOTIFY_USER
181 extern struct ctl_table inotify_table[];
184 extern struct ctl_table epoll_table[];
187 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
188 int sysctl_legacy_va_layout;
191 extern int prove_locking;
192 extern int lock_stat;
194 /* The default sysctl tables: */
196 static struct ctl_table root_table[] = {
198 .ctl_name = CTL_KERN,
199 .procname = "kernel",
216 .ctl_name = CTL_DEBUG,
219 .child = debug_table,
228 * NOTE: do not add new entries to this table unless you have read
229 * Documentation/sysctl/ctl_unnumbered.txt
234 #ifdef CONFIG_SCHED_DEBUG
235 static int min_sched_granularity_ns = 100000; /* 100 usecs */
236 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
237 static int min_wakeup_granularity_ns; /* 0 usecs */
238 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
241 static struct ctl_table kern_table[] = {
242 #ifdef CONFIG_SCHED_DEBUG
244 .ctl_name = CTL_UNNUMBERED,
245 .procname = "sched_min_granularity_ns",
246 .data = &sysctl_sched_min_granularity,
247 .maxlen = sizeof(unsigned int),
249 .proc_handler = &sched_nr_latency_handler,
250 .strategy = &sysctl_intvec,
251 .extra1 = &min_sched_granularity_ns,
252 .extra2 = &max_sched_granularity_ns,
255 .ctl_name = CTL_UNNUMBERED,
256 .procname = "sched_latency_ns",
257 .data = &sysctl_sched_latency,
258 .maxlen = sizeof(unsigned int),
260 .proc_handler = &sched_nr_latency_handler,
261 .strategy = &sysctl_intvec,
262 .extra1 = &min_sched_granularity_ns,
263 .extra2 = &max_sched_granularity_ns,
266 .ctl_name = CTL_UNNUMBERED,
267 .procname = "sched_wakeup_granularity_ns",
268 .data = &sysctl_sched_wakeup_granularity,
269 .maxlen = sizeof(unsigned int),
271 .proc_handler = &proc_dointvec_minmax,
272 .strategy = &sysctl_intvec,
273 .extra1 = &min_wakeup_granularity_ns,
274 .extra2 = &max_wakeup_granularity_ns,
277 .ctl_name = CTL_UNNUMBERED,
278 .procname = "sched_shares_ratelimit",
279 .data = &sysctl_sched_shares_ratelimit,
280 .maxlen = sizeof(unsigned int),
282 .proc_handler = &proc_dointvec,
285 .ctl_name = CTL_UNNUMBERED,
286 .procname = "sched_shares_thresh",
287 .data = &sysctl_sched_shares_thresh,
288 .maxlen = sizeof(unsigned int),
290 .proc_handler = &proc_dointvec_minmax,
291 .strategy = &sysctl_intvec,
295 .ctl_name = CTL_UNNUMBERED,
296 .procname = "sched_child_runs_first",
297 .data = &sysctl_sched_child_runs_first,
298 .maxlen = sizeof(unsigned int),
300 .proc_handler = &proc_dointvec,
303 .ctl_name = CTL_UNNUMBERED,
304 .procname = "sched_features",
305 .data = &sysctl_sched_features,
306 .maxlen = sizeof(unsigned int),
308 .proc_handler = &proc_dointvec,
311 .ctl_name = CTL_UNNUMBERED,
312 .procname = "sched_migration_cost",
313 .data = &sysctl_sched_migration_cost,
314 .maxlen = sizeof(unsigned int),
316 .proc_handler = &proc_dointvec,
319 .ctl_name = CTL_UNNUMBERED,
320 .procname = "sched_nr_migrate",
321 .data = &sysctl_sched_nr_migrate,
322 .maxlen = sizeof(unsigned int),
324 .proc_handler = &proc_dointvec,
328 .ctl_name = CTL_UNNUMBERED,
329 .procname = "sched_rt_period_us",
330 .data = &sysctl_sched_rt_period,
331 .maxlen = sizeof(unsigned int),
333 .proc_handler = &sched_rt_handler,
336 .ctl_name = CTL_UNNUMBERED,
337 .procname = "sched_rt_runtime_us",
338 .data = &sysctl_sched_rt_runtime,
339 .maxlen = sizeof(int),
341 .proc_handler = &sched_rt_handler,
344 .ctl_name = CTL_UNNUMBERED,
345 .procname = "sched_compat_yield",
346 .data = &sysctl_sched_compat_yield,
347 .maxlen = sizeof(unsigned int),
349 .proc_handler = &proc_dointvec,
351 #ifdef CONFIG_PROVE_LOCKING
353 .ctl_name = CTL_UNNUMBERED,
354 .procname = "prove_locking",
355 .data = &prove_locking,
356 .maxlen = sizeof(int),
358 .proc_handler = &proc_dointvec,
361 #ifdef CONFIG_LOCK_STAT
363 .ctl_name = CTL_UNNUMBERED,
364 .procname = "lock_stat",
366 .maxlen = sizeof(int),
368 .proc_handler = &proc_dointvec,
372 .ctl_name = KERN_PANIC,
374 .data = &panic_timeout,
375 .maxlen = sizeof(int),
377 .proc_handler = &proc_dointvec,
380 .ctl_name = KERN_CORE_USES_PID,
381 .procname = "core_uses_pid",
382 .data = &core_uses_pid,
383 .maxlen = sizeof(int),
385 .proc_handler = &proc_dointvec,
388 .ctl_name = KERN_CORE_PATTERN,
389 .procname = "core_pattern",
390 .data = core_pattern,
391 .maxlen = CORENAME_MAX_SIZE,
393 .proc_handler = &proc_dostring,
394 .strategy = &sysctl_string,
396 #ifdef CONFIG_PROC_SYSCTL
398 .procname = "tainted",
399 .maxlen = sizeof(long),
401 .proc_handler = &proc_taint,
404 #ifdef CONFIG_LATENCYTOP
406 .procname = "latencytop",
407 .data = &latencytop_enabled,
408 .maxlen = sizeof(int),
410 .proc_handler = &proc_dointvec,
413 #ifdef CONFIG_BLK_DEV_INITRD
415 .ctl_name = KERN_REALROOTDEV,
416 .procname = "real-root-dev",
417 .data = &real_root_dev,
418 .maxlen = sizeof(int),
420 .proc_handler = &proc_dointvec,
424 .ctl_name = CTL_UNNUMBERED,
425 .procname = "print-fatal-signals",
426 .data = &print_fatal_signals,
427 .maxlen = sizeof(int),
429 .proc_handler = &proc_dointvec,
433 .ctl_name = KERN_SPARC_REBOOT,
434 .procname = "reboot-cmd",
435 .data = reboot_command,
438 .proc_handler = &proc_dostring,
439 .strategy = &sysctl_string,
442 .ctl_name = KERN_SPARC_STOP_A,
443 .procname = "stop-a",
444 .data = &stop_a_enabled,
445 .maxlen = sizeof (int),
447 .proc_handler = &proc_dointvec,
450 .ctl_name = KERN_SPARC_SCONS_PWROFF,
451 .procname = "scons-poweroff",
452 .data = &scons_pwroff,
453 .maxlen = sizeof (int),
455 .proc_handler = &proc_dointvec,
458 #ifdef CONFIG_SPARC64
460 .ctl_name = CTL_UNNUMBERED,
461 .procname = "tsb-ratio",
462 .data = &sysctl_tsb_ratio,
463 .maxlen = sizeof (int),
465 .proc_handler = &proc_dointvec,
470 .ctl_name = KERN_HPPA_PWRSW,
471 .procname = "soft-power",
472 .data = &pwrsw_enabled,
473 .maxlen = sizeof (int),
475 .proc_handler = &proc_dointvec,
478 .ctl_name = KERN_HPPA_UNALIGNED,
479 .procname = "unaligned-trap",
480 .data = &unaligned_enabled,
481 .maxlen = sizeof (int),
483 .proc_handler = &proc_dointvec,
487 .ctl_name = KERN_CTLALTDEL,
488 .procname = "ctrl-alt-del",
490 .maxlen = sizeof(int),
492 .proc_handler = &proc_dointvec,
494 #ifdef CONFIG_FUNCTION_TRACER
496 .ctl_name = CTL_UNNUMBERED,
497 .procname = "ftrace_enabled",
498 .data = &ftrace_enabled,
499 .maxlen = sizeof(int),
501 .proc_handler = &ftrace_enable_sysctl,
504 #ifdef CONFIG_STACK_TRACER
506 .ctl_name = CTL_UNNUMBERED,
507 .procname = "stack_tracer_enabled",
508 .data = &stack_tracer_enabled,
509 .maxlen = sizeof(int),
511 .proc_handler = &stack_trace_sysctl,
514 #ifdef CONFIG_TRACING
516 .ctl_name = CTL_UNNUMBERED,
517 .procname = "ftrace_dump_on_oops",
518 .data = &ftrace_dump_on_oops,
519 .maxlen = sizeof(int),
521 .proc_handler = &proc_dointvec,
524 #ifdef CONFIG_MODULES
526 .ctl_name = KERN_MODPROBE,
527 .procname = "modprobe",
528 .data = &modprobe_path,
529 .maxlen = KMOD_PATH_LEN,
531 .proc_handler = &proc_dostring,
532 .strategy = &sysctl_string,
535 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
537 .ctl_name = KERN_HOTPLUG,
538 .procname = "hotplug",
539 .data = &uevent_helper,
540 .maxlen = UEVENT_HELPER_PATH_LEN,
542 .proc_handler = &proc_dostring,
543 .strategy = &sysctl_string,
546 #ifdef CONFIG_CHR_DEV_SG
548 .ctl_name = KERN_SG_BIG_BUFF,
549 .procname = "sg-big-buff",
550 .data = &sg_big_buff,
551 .maxlen = sizeof (int),
553 .proc_handler = &proc_dointvec,
556 #ifdef CONFIG_BSD_PROCESS_ACCT
558 .ctl_name = KERN_ACCT,
561 .maxlen = 3*sizeof(int),
563 .proc_handler = &proc_dointvec,
566 #ifdef CONFIG_MAGIC_SYSRQ
568 .ctl_name = KERN_SYSRQ,
570 .data = &__sysrq_enabled,
571 .maxlen = sizeof (int),
573 .proc_handler = &proc_dointvec,
576 #ifdef CONFIG_PROC_SYSCTL
578 .procname = "cad_pid",
580 .maxlen = sizeof (int),
582 .proc_handler = &proc_do_cad_pid,
586 .ctl_name = KERN_MAX_THREADS,
587 .procname = "threads-max",
588 .data = &max_threads,
589 .maxlen = sizeof(int),
591 .proc_handler = &proc_dointvec,
594 .ctl_name = KERN_RANDOM,
595 .procname = "random",
597 .child = random_table,
600 .ctl_name = KERN_OVERFLOWUID,
601 .procname = "overflowuid",
602 .data = &overflowuid,
603 .maxlen = sizeof(int),
605 .proc_handler = &proc_dointvec_minmax,
606 .strategy = &sysctl_intvec,
607 .extra1 = &minolduid,
608 .extra2 = &maxolduid,
611 .ctl_name = KERN_OVERFLOWGID,
612 .procname = "overflowgid",
613 .data = &overflowgid,
614 .maxlen = sizeof(int),
616 .proc_handler = &proc_dointvec_minmax,
617 .strategy = &sysctl_intvec,
618 .extra1 = &minolduid,
619 .extra2 = &maxolduid,
622 #ifdef CONFIG_MATHEMU
624 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
625 .procname = "ieee_emulation_warnings",
626 .data = &sysctl_ieee_emulation_warnings,
627 .maxlen = sizeof(int),
629 .proc_handler = &proc_dointvec,
633 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
634 .procname = "userprocess_debug",
635 .data = &sysctl_userprocess_debug,
636 .maxlen = sizeof(int),
638 .proc_handler = &proc_dointvec,
642 .ctl_name = KERN_PIDMAX,
643 .procname = "pid_max",
645 .maxlen = sizeof (int),
647 .proc_handler = &proc_dointvec_minmax,
648 .strategy = sysctl_intvec,
649 .extra1 = &pid_max_min,
650 .extra2 = &pid_max_max,
653 .ctl_name = KERN_PANIC_ON_OOPS,
654 .procname = "panic_on_oops",
655 .data = &panic_on_oops,
656 .maxlen = sizeof(int),
658 .proc_handler = &proc_dointvec,
660 #if defined CONFIG_PRINTK
662 .ctl_name = KERN_PRINTK,
663 .procname = "printk",
664 .data = &console_loglevel,
665 .maxlen = 4*sizeof(int),
667 .proc_handler = &proc_dointvec,
670 .ctl_name = KERN_PRINTK_RATELIMIT,
671 .procname = "printk_ratelimit",
672 .data = &printk_ratelimit_state.interval,
673 .maxlen = sizeof(int),
675 .proc_handler = &proc_dointvec_jiffies,
676 .strategy = &sysctl_jiffies,
679 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
680 .procname = "printk_ratelimit_burst",
681 .data = &printk_ratelimit_state.burst,
682 .maxlen = sizeof(int),
684 .proc_handler = &proc_dointvec,
688 .ctl_name = KERN_NGROUPS_MAX,
689 .procname = "ngroups_max",
690 .data = &ngroups_max,
691 .maxlen = sizeof (int),
693 .proc_handler = &proc_dointvec,
695 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
697 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
698 .procname = "unknown_nmi_panic",
699 .data = &unknown_nmi_panic,
700 .maxlen = sizeof (int),
702 .proc_handler = &proc_dointvec,
705 .procname = "nmi_watchdog",
706 .data = &nmi_watchdog_enabled,
707 .maxlen = sizeof (int),
709 .proc_handler = &proc_nmi_enabled,
712 #if defined(CONFIG_X86)
714 .ctl_name = KERN_PANIC_ON_NMI,
715 .procname = "panic_on_unrecovered_nmi",
716 .data = &panic_on_unrecovered_nmi,
717 .maxlen = sizeof(int),
719 .proc_handler = &proc_dointvec,
722 .ctl_name = KERN_BOOTLOADER_TYPE,
723 .procname = "bootloader_type",
724 .data = &bootloader_type,
725 .maxlen = sizeof (int),
727 .proc_handler = &proc_dointvec,
730 .ctl_name = CTL_UNNUMBERED,
731 .procname = "kstack_depth_to_print",
732 .data = &kstack_depth_to_print,
733 .maxlen = sizeof(int),
735 .proc_handler = &proc_dointvec,
738 .ctl_name = CTL_UNNUMBERED,
739 .procname = "io_delay_type",
740 .data = &io_delay_type,
741 .maxlen = sizeof(int),
743 .proc_handler = &proc_dointvec,
746 #if defined(CONFIG_MMU)
748 .ctl_name = KERN_RANDOMIZE,
749 .procname = "randomize_va_space",
750 .data = &randomize_va_space,
751 .maxlen = sizeof(int),
753 .proc_handler = &proc_dointvec,
756 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
758 .ctl_name = KERN_SPIN_RETRY,
759 .procname = "spin_retry",
761 .maxlen = sizeof (int),
763 .proc_handler = &proc_dointvec,
766 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
768 .procname = "acpi_video_flags",
769 .data = &acpi_realmode_flags,
770 .maxlen = sizeof (unsigned long),
772 .proc_handler = &proc_doulongvec_minmax,
777 .ctl_name = KERN_IA64_UNALIGNED,
778 .procname = "ignore-unaligned-usertrap",
779 .data = &no_unaligned_warning,
780 .maxlen = sizeof (int),
782 .proc_handler = &proc_dointvec,
785 .ctl_name = CTL_UNNUMBERED,
786 .procname = "unaligned-dump-stack",
787 .data = &unaligned_dump_stack,
788 .maxlen = sizeof (int),
790 .proc_handler = &proc_dointvec,
793 #ifdef CONFIG_DETECT_SOFTLOCKUP
795 .ctl_name = CTL_UNNUMBERED,
796 .procname = "softlockup_panic",
797 .data = &softlockup_panic,
798 .maxlen = sizeof(int),
800 .proc_handler = &proc_dointvec_minmax,
801 .strategy = &sysctl_intvec,
806 .ctl_name = CTL_UNNUMBERED,
807 .procname = "softlockup_thresh",
808 .data = &softlockup_thresh,
809 .maxlen = sizeof(int),
811 .proc_handler = &proc_dosoftlockup_thresh,
812 .strategy = &sysctl_intvec,
817 #ifdef CONFIG_DETECT_HUNG_TASK
819 .ctl_name = CTL_UNNUMBERED,
820 .procname = "hung_task_panic",
821 .data = &sysctl_hung_task_panic,
822 .maxlen = sizeof(int),
824 .proc_handler = &proc_dointvec_minmax,
825 .strategy = &sysctl_intvec,
830 .ctl_name = CTL_UNNUMBERED,
831 .procname = "hung_task_check_count",
832 .data = &sysctl_hung_task_check_count,
833 .maxlen = sizeof(unsigned long),
835 .proc_handler = &proc_doulongvec_minmax,
836 .strategy = &sysctl_intvec,
839 .ctl_name = CTL_UNNUMBERED,
840 .procname = "hung_task_timeout_secs",
841 .data = &sysctl_hung_task_timeout_secs,
842 .maxlen = sizeof(unsigned long),
844 .proc_handler = &proc_dohung_task_timeout_secs,
845 .strategy = &sysctl_intvec,
848 .ctl_name = CTL_UNNUMBERED,
849 .procname = "hung_task_warnings",
850 .data = &sysctl_hung_task_warnings,
851 .maxlen = sizeof(unsigned long),
853 .proc_handler = &proc_doulongvec_minmax,
854 .strategy = &sysctl_intvec,
859 .ctl_name = KERN_COMPAT_LOG,
860 .procname = "compat-log",
862 .maxlen = sizeof (int),
864 .proc_handler = &proc_dointvec,
867 #ifdef CONFIG_RT_MUTEXES
869 .ctl_name = KERN_MAX_LOCK_DEPTH,
870 .procname = "max_lock_depth",
871 .data = &max_lock_depth,
872 .maxlen = sizeof(int),
874 .proc_handler = &proc_dointvec,
878 .ctl_name = CTL_UNNUMBERED,
879 .procname = "poweroff_cmd",
880 .data = &poweroff_cmd,
881 .maxlen = POWEROFF_CMD_PATH_LEN,
883 .proc_handler = &proc_dostring,
884 .strategy = &sysctl_string,
888 .ctl_name = CTL_UNNUMBERED,
891 .child = key_sysctls,
894 #ifdef CONFIG_RCU_TORTURE_TEST
896 .ctl_name = CTL_UNNUMBERED,
897 .procname = "rcutorture_runnable",
898 .data = &rcutorture_runnable,
899 .maxlen = sizeof(int),
901 .proc_handler = &proc_dointvec,
904 #ifdef CONFIG_UNEVICTABLE_LRU
906 .ctl_name = CTL_UNNUMBERED,
907 .procname = "scan_unevictable_pages",
908 .data = &scan_unevictable_pages,
909 .maxlen = sizeof(scan_unevictable_pages),
911 .proc_handler = &scan_unevictable_handler,
914 #ifdef CONFIG_SLOW_WORK
916 .ctl_name = CTL_UNNUMBERED,
917 .procname = "slow-work",
919 .child = slow_work_sysctls,
923 * NOTE: do not add new entries to this table unless you have read
924 * Documentation/sysctl/ctl_unnumbered.txt
929 static struct ctl_table vm_table[] = {
931 .ctl_name = VM_OVERCOMMIT_MEMORY,
932 .procname = "overcommit_memory",
933 .data = &sysctl_overcommit_memory,
934 .maxlen = sizeof(sysctl_overcommit_memory),
936 .proc_handler = &proc_dointvec,
939 .ctl_name = VM_PANIC_ON_OOM,
940 .procname = "panic_on_oom",
941 .data = &sysctl_panic_on_oom,
942 .maxlen = sizeof(sysctl_panic_on_oom),
944 .proc_handler = &proc_dointvec,
947 .ctl_name = CTL_UNNUMBERED,
948 .procname = "oom_kill_allocating_task",
949 .data = &sysctl_oom_kill_allocating_task,
950 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
952 .proc_handler = &proc_dointvec,
955 .ctl_name = CTL_UNNUMBERED,
956 .procname = "oom_dump_tasks",
957 .data = &sysctl_oom_dump_tasks,
958 .maxlen = sizeof(sysctl_oom_dump_tasks),
960 .proc_handler = &proc_dointvec,
963 .ctl_name = VM_OVERCOMMIT_RATIO,
964 .procname = "overcommit_ratio",
965 .data = &sysctl_overcommit_ratio,
966 .maxlen = sizeof(sysctl_overcommit_ratio),
968 .proc_handler = &proc_dointvec,
971 .ctl_name = VM_PAGE_CLUSTER,
972 .procname = "page-cluster",
973 .data = &page_cluster,
974 .maxlen = sizeof(int),
976 .proc_handler = &proc_dointvec,
979 .ctl_name = VM_DIRTY_BACKGROUND,
980 .procname = "dirty_background_ratio",
981 .data = &dirty_background_ratio,
982 .maxlen = sizeof(dirty_background_ratio),
984 .proc_handler = &dirty_background_ratio_handler,
985 .strategy = &sysctl_intvec,
987 .extra2 = &one_hundred,
990 .ctl_name = CTL_UNNUMBERED,
991 .procname = "dirty_background_bytes",
992 .data = &dirty_background_bytes,
993 .maxlen = sizeof(dirty_background_bytes),
995 .proc_handler = &dirty_background_bytes_handler,
996 .strategy = &sysctl_intvec,
1000 .ctl_name = VM_DIRTY_RATIO,
1001 .procname = "dirty_ratio",
1002 .data = &vm_dirty_ratio,
1003 .maxlen = sizeof(vm_dirty_ratio),
1005 .proc_handler = &dirty_ratio_handler,
1006 .strategy = &sysctl_intvec,
1008 .extra2 = &one_hundred,
1011 .ctl_name = CTL_UNNUMBERED,
1012 .procname = "dirty_bytes",
1013 .data = &vm_dirty_bytes,
1014 .maxlen = sizeof(vm_dirty_bytes),
1016 .proc_handler = &dirty_bytes_handler,
1017 .strategy = &sysctl_intvec,
1021 .procname = "dirty_writeback_centisecs",
1022 .data = &dirty_writeback_interval,
1023 .maxlen = sizeof(dirty_writeback_interval),
1025 .proc_handler = &dirty_writeback_centisecs_handler,
1028 .procname = "dirty_expire_centisecs",
1029 .data = &dirty_expire_interval,
1030 .maxlen = sizeof(dirty_expire_interval),
1032 .proc_handler = &proc_dointvec,
1035 .ctl_name = VM_NR_PDFLUSH_THREADS,
1036 .procname = "nr_pdflush_threads",
1037 .data = &nr_pdflush_threads,
1038 .maxlen = sizeof nr_pdflush_threads,
1039 .mode = 0444 /* read-only*/,
1040 .proc_handler = &proc_dointvec,
1043 .ctl_name = VM_SWAPPINESS,
1044 .procname = "swappiness",
1045 .data = &vm_swappiness,
1046 .maxlen = sizeof(vm_swappiness),
1048 .proc_handler = &proc_dointvec_minmax,
1049 .strategy = &sysctl_intvec,
1051 .extra2 = &one_hundred,
1053 #ifdef CONFIG_HUGETLB_PAGE
1055 .procname = "nr_hugepages",
1057 .maxlen = sizeof(unsigned long),
1059 .proc_handler = &hugetlb_sysctl_handler,
1060 .extra1 = (void *)&hugetlb_zero,
1061 .extra2 = (void *)&hugetlb_infinity,
1064 .ctl_name = VM_HUGETLB_GROUP,
1065 .procname = "hugetlb_shm_group",
1066 .data = &sysctl_hugetlb_shm_group,
1067 .maxlen = sizeof(gid_t),
1069 .proc_handler = &proc_dointvec,
1072 .ctl_name = CTL_UNNUMBERED,
1073 .procname = "hugepages_treat_as_movable",
1074 .data = &hugepages_treat_as_movable,
1075 .maxlen = sizeof(int),
1077 .proc_handler = &hugetlb_treat_movable_handler,
1080 .ctl_name = CTL_UNNUMBERED,
1081 .procname = "nr_overcommit_hugepages",
1083 .maxlen = sizeof(unsigned long),
1085 .proc_handler = &hugetlb_overcommit_handler,
1086 .extra1 = (void *)&hugetlb_zero,
1087 .extra2 = (void *)&hugetlb_infinity,
1091 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1092 .procname = "lowmem_reserve_ratio",
1093 .data = &sysctl_lowmem_reserve_ratio,
1094 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1096 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1097 .strategy = &sysctl_intvec,
1100 .ctl_name = VM_DROP_PAGECACHE,
1101 .procname = "drop_caches",
1102 .data = &sysctl_drop_caches,
1103 .maxlen = sizeof(int),
1105 .proc_handler = drop_caches_sysctl_handler,
1106 .strategy = &sysctl_intvec,
1109 .ctl_name = VM_MIN_FREE_KBYTES,
1110 .procname = "min_free_kbytes",
1111 .data = &min_free_kbytes,
1112 .maxlen = sizeof(min_free_kbytes),
1114 .proc_handler = &min_free_kbytes_sysctl_handler,
1115 .strategy = &sysctl_intvec,
1119 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1120 .procname = "percpu_pagelist_fraction",
1121 .data = &percpu_pagelist_fraction,
1122 .maxlen = sizeof(percpu_pagelist_fraction),
1124 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1125 .strategy = &sysctl_intvec,
1126 .extra1 = &min_percpu_pagelist_fract,
1130 .ctl_name = VM_MAX_MAP_COUNT,
1131 .procname = "max_map_count",
1132 .data = &sysctl_max_map_count,
1133 .maxlen = sizeof(sysctl_max_map_count),
1135 .proc_handler = &proc_dointvec
1139 .ctl_name = CTL_UNNUMBERED,
1140 .procname = "nr_trim_pages",
1141 .data = &sysctl_nr_trim_pages,
1142 .maxlen = sizeof(sysctl_nr_trim_pages),
1144 .proc_handler = &proc_dointvec_minmax,
1145 .strategy = &sysctl_intvec,
1150 .ctl_name = VM_LAPTOP_MODE,
1151 .procname = "laptop_mode",
1152 .data = &laptop_mode,
1153 .maxlen = sizeof(laptop_mode),
1155 .proc_handler = &proc_dointvec_jiffies,
1156 .strategy = &sysctl_jiffies,
1159 .ctl_name = VM_BLOCK_DUMP,
1160 .procname = "block_dump",
1161 .data = &block_dump,
1162 .maxlen = sizeof(block_dump),
1164 .proc_handler = &proc_dointvec,
1165 .strategy = &sysctl_intvec,
1169 .ctl_name = VM_VFS_CACHE_PRESSURE,
1170 .procname = "vfs_cache_pressure",
1171 .data = &sysctl_vfs_cache_pressure,
1172 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1174 .proc_handler = &proc_dointvec,
1175 .strategy = &sysctl_intvec,
1178 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1180 .ctl_name = VM_LEGACY_VA_LAYOUT,
1181 .procname = "legacy_va_layout",
1182 .data = &sysctl_legacy_va_layout,
1183 .maxlen = sizeof(sysctl_legacy_va_layout),
1185 .proc_handler = &proc_dointvec,
1186 .strategy = &sysctl_intvec,
1192 .ctl_name = VM_ZONE_RECLAIM_MODE,
1193 .procname = "zone_reclaim_mode",
1194 .data = &zone_reclaim_mode,
1195 .maxlen = sizeof(zone_reclaim_mode),
1197 .proc_handler = &proc_dointvec,
1198 .strategy = &sysctl_intvec,
1202 .ctl_name = VM_MIN_UNMAPPED,
1203 .procname = "min_unmapped_ratio",
1204 .data = &sysctl_min_unmapped_ratio,
1205 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1207 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1208 .strategy = &sysctl_intvec,
1210 .extra2 = &one_hundred,
1213 .ctl_name = VM_MIN_SLAB,
1214 .procname = "min_slab_ratio",
1215 .data = &sysctl_min_slab_ratio,
1216 .maxlen = sizeof(sysctl_min_slab_ratio),
1218 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1219 .strategy = &sysctl_intvec,
1221 .extra2 = &one_hundred,
1226 .ctl_name = CTL_UNNUMBERED,
1227 .procname = "stat_interval",
1228 .data = &sysctl_stat_interval,
1229 .maxlen = sizeof(sysctl_stat_interval),
1231 .proc_handler = &proc_dointvec_jiffies,
1232 .strategy = &sysctl_jiffies,
1235 #ifdef CONFIG_SECURITY
1237 .ctl_name = CTL_UNNUMBERED,
1238 .procname = "mmap_min_addr",
1239 .data = &mmap_min_addr,
1240 .maxlen = sizeof(unsigned long),
1242 .proc_handler = &proc_doulongvec_minmax,
1247 .ctl_name = CTL_UNNUMBERED,
1248 .procname = "numa_zonelist_order",
1249 .data = &numa_zonelist_order,
1250 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1252 .proc_handler = &numa_zonelist_order_handler,
1253 .strategy = &sysctl_string,
1256 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1257 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1259 .ctl_name = VM_VDSO_ENABLED,
1260 .procname = "vdso_enabled",
1261 .data = &vdso_enabled,
1262 .maxlen = sizeof(vdso_enabled),
1264 .proc_handler = &proc_dointvec,
1265 .strategy = &sysctl_intvec,
1269 #ifdef CONFIG_HIGHMEM
1271 .ctl_name = CTL_UNNUMBERED,
1272 .procname = "highmem_is_dirtyable",
1273 .data = &vm_highmem_is_dirtyable,
1274 .maxlen = sizeof(vm_highmem_is_dirtyable),
1276 .proc_handler = &proc_dointvec_minmax,
1277 .strategy = &sysctl_intvec,
1283 * NOTE: do not add new entries to this table unless you have read
1284 * Documentation/sysctl/ctl_unnumbered.txt
1289 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1290 static struct ctl_table binfmt_misc_table[] = {
1295 static struct ctl_table fs_table[] = {
1297 .ctl_name = FS_NRINODE,
1298 .procname = "inode-nr",
1299 .data = &inodes_stat,
1300 .maxlen = 2*sizeof(int),
1302 .proc_handler = &proc_dointvec,
1305 .ctl_name = FS_STATINODE,
1306 .procname = "inode-state",
1307 .data = &inodes_stat,
1308 .maxlen = 7*sizeof(int),
1310 .proc_handler = &proc_dointvec,
1313 .procname = "file-nr",
1314 .data = &files_stat,
1315 .maxlen = 3*sizeof(int),
1317 .proc_handler = &proc_nr_files,
1320 .ctl_name = FS_MAXFILE,
1321 .procname = "file-max",
1322 .data = &files_stat.max_files,
1323 .maxlen = sizeof(int),
1325 .proc_handler = &proc_dointvec,
1328 .ctl_name = CTL_UNNUMBERED,
1329 .procname = "nr_open",
1330 .data = &sysctl_nr_open,
1331 .maxlen = sizeof(int),
1333 .proc_handler = &proc_dointvec_minmax,
1334 .extra1 = &sysctl_nr_open_min,
1335 .extra2 = &sysctl_nr_open_max,
1338 .ctl_name = FS_DENTRY,
1339 .procname = "dentry-state",
1340 .data = &dentry_stat,
1341 .maxlen = 6*sizeof(int),
1343 .proc_handler = &proc_dointvec,
1346 .ctl_name = FS_OVERFLOWUID,
1347 .procname = "overflowuid",
1348 .data = &fs_overflowuid,
1349 .maxlen = sizeof(int),
1351 .proc_handler = &proc_dointvec_minmax,
1352 .strategy = &sysctl_intvec,
1353 .extra1 = &minolduid,
1354 .extra2 = &maxolduid,
1357 .ctl_name = FS_OVERFLOWGID,
1358 .procname = "overflowgid",
1359 .data = &fs_overflowgid,
1360 .maxlen = sizeof(int),
1362 .proc_handler = &proc_dointvec_minmax,
1363 .strategy = &sysctl_intvec,
1364 .extra1 = &minolduid,
1365 .extra2 = &maxolduid,
1367 #ifdef CONFIG_FILE_LOCKING
1369 .ctl_name = FS_LEASES,
1370 .procname = "leases-enable",
1371 .data = &leases_enable,
1372 .maxlen = sizeof(int),
1374 .proc_handler = &proc_dointvec,
1377 #ifdef CONFIG_DNOTIFY
1379 .ctl_name = FS_DIR_NOTIFY,
1380 .procname = "dir-notify-enable",
1381 .data = &dir_notify_enable,
1382 .maxlen = sizeof(int),
1384 .proc_handler = &proc_dointvec,
1388 #ifdef CONFIG_FILE_LOCKING
1390 .ctl_name = FS_LEASE_TIME,
1391 .procname = "lease-break-time",
1392 .data = &lease_break_time,
1393 .maxlen = sizeof(int),
1395 .proc_handler = &proc_dointvec,
1400 .procname = "aio-nr",
1402 .maxlen = sizeof(aio_nr),
1404 .proc_handler = &proc_doulongvec_minmax,
1407 .procname = "aio-max-nr",
1408 .data = &aio_max_nr,
1409 .maxlen = sizeof(aio_max_nr),
1411 .proc_handler = &proc_doulongvec_minmax,
1413 #endif /* CONFIG_AIO */
1414 #ifdef CONFIG_INOTIFY_USER
1416 .ctl_name = FS_INOTIFY,
1417 .procname = "inotify",
1419 .child = inotify_table,
1424 .procname = "epoll",
1426 .child = epoll_table,
1431 .ctl_name = KERN_SETUID_DUMPABLE,
1432 .procname = "suid_dumpable",
1433 .data = &suid_dumpable,
1434 .maxlen = sizeof(int),
1436 .proc_handler = &proc_dointvec_minmax,
1437 .strategy = &sysctl_intvec,
1441 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1443 .ctl_name = CTL_UNNUMBERED,
1444 .procname = "binfmt_misc",
1446 .child = binfmt_misc_table,
1450 * NOTE: do not add new entries to this table unless you have read
1451 * Documentation/sysctl/ctl_unnumbered.txt
1456 static struct ctl_table debug_table[] = {
1457 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1459 .ctl_name = CTL_UNNUMBERED,
1460 .procname = "exception-trace",
1461 .data = &show_unhandled_signals,
1462 .maxlen = sizeof(int),
1464 .proc_handler = proc_dointvec
1470 static struct ctl_table dev_table[] = {
1474 static DEFINE_SPINLOCK(sysctl_lock);
1476 /* called under sysctl_lock */
1477 static int use_table(struct ctl_table_header *p)
1479 if (unlikely(p->unregistering))
1485 /* called under sysctl_lock */
1486 static void unuse_table(struct ctl_table_header *p)
1489 if (unlikely(p->unregistering))
1490 complete(p->unregistering);
1493 /* called under sysctl_lock, will reacquire if has to wait */
1494 static void start_unregistering(struct ctl_table_header *p)
1497 * if p->used is 0, nobody will ever touch that entry again;
1498 * we'll eliminate all paths to it before dropping sysctl_lock
1500 if (unlikely(p->used)) {
1501 struct completion wait;
1502 init_completion(&wait);
1503 p->unregistering = &wait;
1504 spin_unlock(&sysctl_lock);
1505 wait_for_completion(&wait);
1506 spin_lock(&sysctl_lock);
1508 /* anything non-NULL; we'll never dereference it */
1509 p->unregistering = ERR_PTR(-EINVAL);
1512 * do not remove from the list until nobody holds it; walking the
1513 * list in do_sysctl() relies on that.
1515 list_del_init(&p->ctl_entry);
1518 void sysctl_head_get(struct ctl_table_header *head)
1520 spin_lock(&sysctl_lock);
1522 spin_unlock(&sysctl_lock);
1525 void sysctl_head_put(struct ctl_table_header *head)
1527 spin_lock(&sysctl_lock);
1530 spin_unlock(&sysctl_lock);
1533 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1537 spin_lock(&sysctl_lock);
1538 if (!use_table(head))
1539 head = ERR_PTR(-ENOENT);
1540 spin_unlock(&sysctl_lock);
1544 void sysctl_head_finish(struct ctl_table_header *head)
1548 spin_lock(&sysctl_lock);
1550 spin_unlock(&sysctl_lock);
1553 static struct ctl_table_set *
1554 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1556 struct ctl_table_set *set = &root->default_set;
1558 set = root->lookup(root, namespaces);
1562 static struct list_head *
1563 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1565 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1569 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1570 struct ctl_table_header *prev)
1572 struct ctl_table_root *root;
1573 struct list_head *header_list;
1574 struct ctl_table_header *head;
1575 struct list_head *tmp;
1577 spin_lock(&sysctl_lock);
1580 tmp = &prev->ctl_entry;
1584 tmp = &root_table_header.ctl_entry;
1586 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1588 if (!use_table(head))
1590 spin_unlock(&sysctl_lock);
1595 header_list = lookup_header_list(root, namespaces);
1596 if (tmp != header_list)
1600 root = list_entry(root->root_list.next,
1601 struct ctl_table_root, root_list);
1602 if (root == &sysctl_table_root)
1604 header_list = lookup_header_list(root, namespaces);
1605 } while (list_empty(header_list));
1606 tmp = header_list->next;
1609 spin_unlock(&sysctl_lock);
1613 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1615 return __sysctl_head_next(current->nsproxy, prev);
1618 void register_sysctl_root(struct ctl_table_root *root)
1620 spin_lock(&sysctl_lock);
1621 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1622 spin_unlock(&sysctl_lock);
1625 #ifdef CONFIG_SYSCTL_SYSCALL
1626 /* Perform the actual read/write of a sysctl table entry. */
1627 static int do_sysctl_strategy(struct ctl_table_root *root,
1628 struct ctl_table *table,
1629 void __user *oldval, size_t __user *oldlenp,
1630 void __user *newval, size_t newlen)
1638 if (sysctl_perm(root, table, op))
1641 if (table->strategy) {
1642 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1649 /* If there is no strategy routine, or if the strategy returns
1650 * zero, proceed with automatic r/w */
1651 if (table->data && table->maxlen) {
1652 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1659 static int parse_table(int __user *name, int nlen,
1660 void __user *oldval, size_t __user *oldlenp,
1661 void __user *newval, size_t newlen,
1662 struct ctl_table_root *root,
1663 struct ctl_table *table)
1669 if (get_user(n, name))
1671 for ( ; table->ctl_name || table->procname; table++) {
1672 if (!table->ctl_name)
1674 if (n == table->ctl_name) {
1677 if (sysctl_perm(root, table, MAY_EXEC))
1681 table = table->child;
1684 error = do_sysctl_strategy(root, table,
1693 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1694 void __user *newval, size_t newlen)
1696 struct ctl_table_header *head;
1697 int error = -ENOTDIR;
1699 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1703 if (!oldlenp || get_user(old_len, oldlenp))
1707 for (head = sysctl_head_next(NULL); head;
1708 head = sysctl_head_next(head)) {
1709 error = parse_table(name, nlen, oldval, oldlenp,
1711 head->root, head->ctl_table);
1712 if (error != -ENOTDIR) {
1713 sysctl_head_finish(head);
1720 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1722 struct __sysctl_args tmp;
1725 if (copy_from_user(&tmp, args, sizeof(tmp)))
1728 error = deprecated_sysctl_warning(&tmp);
1733 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1734 tmp.newval, tmp.newlen);
1739 #endif /* CONFIG_SYSCTL_SYSCALL */
1742 * sysctl_perm does NOT grant the superuser all rights automatically, because
1743 * some sysctl variables are readonly even to root.
1746 static int test_perm(int mode, int op)
1748 if (!current_euid())
1750 else if (in_egroup_p(0))
1752 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1757 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1762 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1766 if (root->permissions)
1767 mode = root->permissions(root, current->nsproxy, table);
1771 return test_perm(mode, op);
1774 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1776 for (; table->ctl_name || table->procname; table++) {
1777 table->parent = parent;
1779 sysctl_set_parent(table, table->child);
1783 static __init int sysctl_init(void)
1785 sysctl_set_parent(NULL, root_table);
1786 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1789 err = sysctl_check_table(current->nsproxy, root_table);
1795 core_initcall(sysctl_init);
1797 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1798 struct ctl_table *table)
1800 struct ctl_table *p;
1801 const char *s = branch->procname;
1803 /* branch should have named subdirectory as its first element */
1804 if (!s || !branch->child)
1807 /* ... and nothing else */
1808 if (branch[1].procname || branch[1].ctl_name)
1811 /* table should contain subdirectory with the same name */
1812 for (p = table; p->procname || p->ctl_name; p++) {
1815 if (p->procname && strcmp(p->procname, s) == 0)
1821 /* see if attaching q to p would be an improvement */
1822 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1824 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1825 struct ctl_table *next;
1827 int not_in_parent = !p->attached_by;
1829 while ((next = is_branch_in(by, to)) != NULL) {
1830 if (by == q->attached_by)
1832 if (to == p->attached_by)
1838 if (is_better && not_in_parent) {
1839 q->attached_by = by;
1840 q->attached_to = to;
1846 * __register_sysctl_paths - register a sysctl hierarchy
1847 * @root: List of sysctl headers to register on
1848 * @namespaces: Data to compute which lists of sysctl entries are visible
1849 * @path: The path to the directory the sysctl table is in.
1850 * @table: the top-level table structure
1852 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1853 * array. A completely 0 filled entry terminates the table.
1855 * The members of the &struct ctl_table structure are used as follows:
1857 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1858 * must be unique within that level of sysctl
1860 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1861 * enter a sysctl file
1863 * data - a pointer to data for use by proc_handler
1865 * maxlen - the maximum size in bytes of the data
1867 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1869 * child - a pointer to the child sysctl table if this entry is a directory, or
1872 * proc_handler - the text handler routine (described below)
1874 * strategy - the strategy routine (described below)
1876 * de - for internal use by the sysctl routines
1878 * extra1, extra2 - extra pointers usable by the proc handler routines
1880 * Leaf nodes in the sysctl tree will be represented by a single file
1881 * under /proc; non-leaf nodes will be represented by directories.
1883 * sysctl(2) can automatically manage read and write requests through
1884 * the sysctl table. The data and maxlen fields of the ctl_table
1885 * struct enable minimal validation of the values being written to be
1886 * performed, and the mode field allows minimal authentication.
1888 * More sophisticated management can be enabled by the provision of a
1889 * strategy routine with the table entry. This will be called before
1890 * any automatic read or write of the data is performed.
1892 * The strategy routine may return
1894 * < 0 - Error occurred (error is passed to user process)
1896 * 0 - OK - proceed with automatic read or write.
1898 * > 0 - OK - read or write has been done by the strategy routine, so
1899 * return immediately.
1901 * There must be a proc_handler routine for any terminal nodes
1902 * mirrored under /proc/sys (non-terminals are handled by a built-in
1903 * directory handler). Several default handlers are available to
1904 * cover common cases -
1906 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1907 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1908 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1910 * It is the handler's job to read the input buffer from user memory
1911 * and process it. The handler should return 0 on success.
1913 * This routine returns %NULL on a failure to register, and a pointer
1914 * to the table header on success.
1916 struct ctl_table_header *__register_sysctl_paths(
1917 struct ctl_table_root *root,
1918 struct nsproxy *namespaces,
1919 const struct ctl_path *path, struct ctl_table *table)
1921 struct ctl_table_header *header;
1922 struct ctl_table *new, **prevp;
1923 unsigned int n, npath;
1924 struct ctl_table_set *set;
1926 /* Count the path components */
1927 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1931 * For each path component, allocate a 2-element ctl_table array.
1932 * The first array element will be filled with the sysctl entry
1933 * for this, the second will be the sentinel (ctl_name == 0).
1935 * We allocate everything in one go so that we don't have to
1936 * worry about freeing additional memory in unregister_sysctl_table.
1938 header = kzalloc(sizeof(struct ctl_table_header) +
1939 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1943 new = (struct ctl_table *) (header + 1);
1945 /* Now connect the dots */
1946 prevp = &header->ctl_table;
1947 for (n = 0; n < npath; ++n, ++path) {
1948 /* Copy the procname */
1949 new->procname = path->procname;
1950 new->ctl_name = path->ctl_name;
1954 prevp = &new->child;
1959 header->ctl_table_arg = table;
1961 INIT_LIST_HEAD(&header->ctl_entry);
1963 header->unregistering = NULL;
1964 header->root = root;
1965 sysctl_set_parent(NULL, header->ctl_table);
1967 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1968 if (sysctl_check_table(namespaces, header->ctl_table)) {
1973 spin_lock(&sysctl_lock);
1974 header->set = lookup_header_set(root, namespaces);
1975 header->attached_by = header->ctl_table;
1976 header->attached_to = root_table;
1977 header->parent = &root_table_header;
1978 for (set = header->set; set; set = set->parent) {
1979 struct ctl_table_header *p;
1980 list_for_each_entry(p, &set->list, ctl_entry) {
1981 if (p->unregistering)
1983 try_attach(p, header);
1986 header->parent->count++;
1987 list_add_tail(&header->ctl_entry, &header->set->list);
1988 spin_unlock(&sysctl_lock);
1994 * register_sysctl_table_path - register a sysctl table hierarchy
1995 * @path: The path to the directory the sysctl table is in.
1996 * @table: the top-level table structure
1998 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1999 * array. A completely 0 filled entry terminates the table.
2001 * See __register_sysctl_paths for more details.
2003 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2004 struct ctl_table *table)
2006 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2011 * register_sysctl_table - register a sysctl table hierarchy
2012 * @table: the top-level table structure
2014 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2015 * array. A completely 0 filled entry terminates the table.
2017 * See register_sysctl_paths for more details.
2019 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2021 static const struct ctl_path null_path[] = { {} };
2023 return register_sysctl_paths(null_path, table);
2027 * unregister_sysctl_table - unregister a sysctl table hierarchy
2028 * @header: the header returned from register_sysctl_table
2030 * Unregisters the sysctl table and all children. proc entries may not
2031 * actually be removed until they are no longer used by anyone.
2033 void unregister_sysctl_table(struct ctl_table_header * header)
2040 spin_lock(&sysctl_lock);
2041 start_unregistering(header);
2042 if (!--header->parent->count) {
2044 kfree(header->parent);
2046 if (!--header->count)
2048 spin_unlock(&sysctl_lock);
2051 int sysctl_is_seen(struct ctl_table_header *p)
2053 struct ctl_table_set *set = p->set;
2055 spin_lock(&sysctl_lock);
2056 if (p->unregistering)
2058 else if (!set->is_seen)
2061 res = set->is_seen(set);
2062 spin_unlock(&sysctl_lock);
2066 void setup_sysctl_set(struct ctl_table_set *p,
2067 struct ctl_table_set *parent,
2068 int (*is_seen)(struct ctl_table_set *))
2070 INIT_LIST_HEAD(&p->list);
2071 p->parent = parent ? parent : &sysctl_table_root.default_set;
2072 p->is_seen = is_seen;
2075 #else /* !CONFIG_SYSCTL */
2076 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2081 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2082 struct ctl_table *table)
2087 void unregister_sysctl_table(struct ctl_table_header * table)
2091 void setup_sysctl_set(struct ctl_table_set *p,
2092 struct ctl_table_set *parent,
2093 int (*is_seen)(struct ctl_table_set *))
2097 void sysctl_head_put(struct ctl_table_header *head)
2101 #endif /* CONFIG_SYSCTL */
2107 #ifdef CONFIG_PROC_SYSCTL
2109 static int _proc_do_string(void* data, int maxlen, int write,
2110 struct file *filp, void __user *buffer,
2111 size_t *lenp, loff_t *ppos)
2117 if (!data || !maxlen || !*lenp) {
2125 while (len < *lenp) {
2126 if (get_user(c, p++))
2128 if (c == 0 || c == '\n')
2134 if(copy_from_user(data, buffer, len))
2136 ((char *) data)[len] = 0;
2154 if(copy_to_user(buffer, data, len))
2157 if(put_user('\n', ((char __user *) buffer) + len))
2168 * proc_dostring - read a string sysctl
2169 * @table: the sysctl table
2170 * @write: %TRUE if this is a write to the sysctl file
2171 * @filp: the file structure
2172 * @buffer: the user buffer
2173 * @lenp: the size of the user buffer
2174 * @ppos: file position
2176 * Reads/writes a string from/to the user buffer. If the kernel
2177 * buffer provided is not large enough to hold the string, the
2178 * string is truncated. The copied string is %NULL-terminated.
2179 * If the string is being read by the user process, it is copied
2180 * and a newline '\n' is added. It is truncated if the buffer is
2183 * Returns 0 on success.
2185 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2186 void __user *buffer, size_t *lenp, loff_t *ppos)
2188 return _proc_do_string(table->data, table->maxlen, write, filp,
2189 buffer, lenp, ppos);
2193 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2195 int write, void *data)
2198 *valp = *negp ? -*lvalp : *lvalp;
2203 *lvalp = (unsigned long)-val;
2206 *lvalp = (unsigned long)val;
2212 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2213 int write, struct file *filp, void __user *buffer,
2214 size_t *lenp, loff_t *ppos,
2215 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2216 int write, void *data),
2219 #define TMPBUFLEN 21
2220 int *i, vleft, first=1, neg, val;
2224 char buf[TMPBUFLEN], *p;
2225 char __user *s = buffer;
2227 if (!tbl_data || !table->maxlen || !*lenp ||
2228 (*ppos && !write)) {
2233 i = (int *) tbl_data;
2234 vleft = table->maxlen / sizeof(*i);
2238 conv = do_proc_dointvec_conv;
2240 for (; left && vleft--; i++, first=0) {
2255 if (len > sizeof(buf) - 1)
2256 len = sizeof(buf) - 1;
2257 if (copy_from_user(buf, s, len))
2261 if (*p == '-' && left > 1) {
2265 if (*p < '0' || *p > '9')
2268 lval = simple_strtoul(p, &p, 0);
2271 if ((len < left) && *p && !isspace(*p))
2278 if (conv(&neg, &lval, i, 1, data))
2285 if (conv(&neg, &lval, i, 0, data))
2288 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2292 if(copy_to_user(s, buf, len))
2299 if (!write && !first && left) {
2300 if(put_user('\n', s))
2307 if (get_user(c, s++))
2322 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2323 void __user *buffer, size_t *lenp, loff_t *ppos,
2324 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2325 int write, void *data),
2328 return __do_proc_dointvec(table->data, table, write, filp,
2329 buffer, lenp, ppos, conv, data);
2333 * proc_dointvec - read a vector of integers
2334 * @table: the sysctl table
2335 * @write: %TRUE if this is a write to the sysctl file
2336 * @filp: the file structure
2337 * @buffer: the user buffer
2338 * @lenp: the size of the user buffer
2339 * @ppos: file position
2341 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2342 * values from/to the user buffer, treated as an ASCII string.
2344 * Returns 0 on success.
2346 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2347 void __user *buffer, size_t *lenp, loff_t *ppos)
2349 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2354 * Taint values can only be increased
2355 * This means we can safely use a temporary.
2357 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2358 void __user *buffer, size_t *lenp, loff_t *ppos)
2361 unsigned long tmptaint = get_taint();
2364 if (write && !capable(CAP_SYS_ADMIN))
2369 err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2375 * Poor man's atomic or. Not worth adding a primitive
2376 * to everyone's atomic.h for this
2379 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2380 if ((tmptaint >> i) & 1)
2388 struct do_proc_dointvec_minmax_conv_param {
2393 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2395 int write, void *data)
2397 struct do_proc_dointvec_minmax_conv_param *param = data;
2399 int val = *negp ? -*lvalp : *lvalp;
2400 if ((param->min && *param->min > val) ||
2401 (param->max && *param->max < val))
2408 *lvalp = (unsigned long)-val;
2411 *lvalp = (unsigned long)val;
2418 * proc_dointvec_minmax - read a vector of integers with min/max values
2419 * @table: the sysctl table
2420 * @write: %TRUE if this is a write to the sysctl file
2421 * @filp: the file structure
2422 * @buffer: the user buffer
2423 * @lenp: the size of the user buffer
2424 * @ppos: file position
2426 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2427 * values from/to the user buffer, treated as an ASCII string.
2429 * This routine will ensure the values are within the range specified by
2430 * table->extra1 (min) and table->extra2 (max).
2432 * Returns 0 on success.
2434 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2435 void __user *buffer, size_t *lenp, loff_t *ppos)
2437 struct do_proc_dointvec_minmax_conv_param param = {
2438 .min = (int *) table->extra1,
2439 .max = (int *) table->extra2,
2441 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2442 do_proc_dointvec_minmax_conv, ¶m);
2445 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2447 void __user *buffer,
2448 size_t *lenp, loff_t *ppos,
2449 unsigned long convmul,
2450 unsigned long convdiv)
2452 #define TMPBUFLEN 21
2453 unsigned long *i, *min, *max, val;
2454 int vleft, first=1, neg;
2456 char buf[TMPBUFLEN], *p;
2457 char __user *s = buffer;
2459 if (!data || !table->maxlen || !*lenp ||
2460 (*ppos && !write)) {
2465 i = (unsigned long *) data;
2466 min = (unsigned long *) table->extra1;
2467 max = (unsigned long *) table->extra2;
2468 vleft = table->maxlen / sizeof(unsigned long);
2471 for (; left && vleft--; i++, min++, max++, first=0) {
2486 if (len > TMPBUFLEN-1)
2488 if (copy_from_user(buf, s, len))
2492 if (*p == '-' && left > 1) {
2496 if (*p < '0' || *p > '9')
2498 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2500 if ((len < left) && *p && !isspace(*p))
2509 if ((min && val < *min) || (max && val > *max))
2516 sprintf(p, "%lu", convdiv * (*i) / convmul);
2520 if(copy_to_user(s, buf, len))
2527 if (!write && !first && left) {
2528 if(put_user('\n', s))
2535 if (get_user(c, s++))
2550 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2552 void __user *buffer,
2553 size_t *lenp, loff_t *ppos,
2554 unsigned long convmul,
2555 unsigned long convdiv)
2557 return __do_proc_doulongvec_minmax(table->data, table, write,
2558 filp, buffer, lenp, ppos, convmul, convdiv);
2562 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2563 * @table: the sysctl table
2564 * @write: %TRUE if this is a write to the sysctl file
2565 * @filp: the file structure
2566 * @buffer: the user buffer
2567 * @lenp: the size of the user buffer
2568 * @ppos: file position
2570 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2571 * values from/to the user buffer, treated as an ASCII string.
2573 * This routine will ensure the values are within the range specified by
2574 * table->extra1 (min) and table->extra2 (max).
2576 * Returns 0 on success.
2578 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2579 void __user *buffer, size_t *lenp, loff_t *ppos)
2581 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2585 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2586 * @table: the sysctl table
2587 * @write: %TRUE if this is a write to the sysctl file
2588 * @filp: the file structure
2589 * @buffer: the user buffer
2590 * @lenp: the size of the user buffer
2591 * @ppos: file position
2593 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2594 * values from/to the user buffer, treated as an ASCII string. The values
2595 * are treated as milliseconds, and converted to jiffies when they are stored.
2597 * This routine will ensure the values are within the range specified by
2598 * table->extra1 (min) and table->extra2 (max).
2600 * Returns 0 on success.
2602 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2604 void __user *buffer,
2605 size_t *lenp, loff_t *ppos)
2607 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2608 lenp, ppos, HZ, 1000l);
2612 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2614 int write, void *data)
2617 if (*lvalp > LONG_MAX / HZ)
2619 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2625 lval = (unsigned long)-val;
2628 lval = (unsigned long)val;
2635 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2637 int write, void *data)
2640 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2642 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2648 lval = (unsigned long)-val;
2651 lval = (unsigned long)val;
2653 *lvalp = jiffies_to_clock_t(lval);
2658 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2660 int write, void *data)
2663 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2669 lval = (unsigned long)-val;
2672 lval = (unsigned long)val;
2674 *lvalp = jiffies_to_msecs(lval);
2680 * proc_dointvec_jiffies - read a vector of integers as seconds
2681 * @table: the sysctl table
2682 * @write: %TRUE if this is a write to the sysctl file
2683 * @filp: the file structure
2684 * @buffer: the user buffer
2685 * @lenp: the size of the user buffer
2686 * @ppos: file position
2688 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2689 * values from/to the user buffer, treated as an ASCII string.
2690 * The values read are assumed to be in seconds, and are converted into
2693 * Returns 0 on success.
2695 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2696 void __user *buffer, size_t *lenp, loff_t *ppos)
2698 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2699 do_proc_dointvec_jiffies_conv,NULL);
2703 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2704 * @table: the sysctl table
2705 * @write: %TRUE if this is a write to the sysctl file
2706 * @filp: the file structure
2707 * @buffer: the user buffer
2708 * @lenp: the size of the user buffer
2709 * @ppos: pointer to the file position
2711 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2712 * values from/to the user buffer, treated as an ASCII string.
2713 * The values read are assumed to be in 1/USER_HZ seconds, and
2714 * are converted into jiffies.
2716 * Returns 0 on success.
2718 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2719 void __user *buffer, size_t *lenp, loff_t *ppos)
2721 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2722 do_proc_dointvec_userhz_jiffies_conv,NULL);
2726 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2727 * @table: the sysctl table
2728 * @write: %TRUE if this is a write to the sysctl file
2729 * @filp: the file structure
2730 * @buffer: the user buffer
2731 * @lenp: the size of the user buffer
2732 * @ppos: file position
2733 * @ppos: the current position in the file
2735 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2736 * values from/to the user buffer, treated as an ASCII string.
2737 * The values read are assumed to be in 1/1000 seconds, and
2738 * are converted into jiffies.
2740 * Returns 0 on success.
2742 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2743 void __user *buffer, size_t *lenp, loff_t *ppos)
2745 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2746 do_proc_dointvec_ms_jiffies_conv, NULL);
2749 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2750 void __user *buffer, size_t *lenp, loff_t *ppos)
2752 struct pid *new_pid;
2756 tmp = pid_vnr(cad_pid);
2758 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2759 lenp, ppos, NULL, NULL);
2763 new_pid = find_get_pid(tmp);
2767 put_pid(xchg(&cad_pid, new_pid));
2771 #else /* CONFIG_PROC_FS */
2773 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2774 void __user *buffer, size_t *lenp, loff_t *ppos)
2779 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2780 void __user *buffer, size_t *lenp, loff_t *ppos)
2785 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2786 void __user *buffer, size_t *lenp, loff_t *ppos)
2791 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2792 void __user *buffer, size_t *lenp, loff_t *ppos)
2797 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2798 void __user *buffer, size_t *lenp, loff_t *ppos)
2803 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2804 void __user *buffer, size_t *lenp, loff_t *ppos)
2809 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2810 void __user *buffer, size_t *lenp, loff_t *ppos)
2815 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2817 void __user *buffer,
2818 size_t *lenp, loff_t *ppos)
2824 #endif /* CONFIG_PROC_FS */
2827 #ifdef CONFIG_SYSCTL_SYSCALL
2829 * General sysctl support routines
2832 /* The generic sysctl data routine (used if no strategy routine supplied) */
2833 int sysctl_data(struct ctl_table *table,
2834 void __user *oldval, size_t __user *oldlenp,
2835 void __user *newval, size_t newlen)
2839 /* Get out of I don't have a variable */
2840 if (!table->data || !table->maxlen)
2843 if (oldval && oldlenp) {
2844 if (get_user(len, oldlenp))
2847 if (len > table->maxlen)
2848 len = table->maxlen;
2849 if (copy_to_user(oldval, table->data, len))
2851 if (put_user(len, oldlenp))
2856 if (newval && newlen) {
2857 if (newlen > table->maxlen)
2858 newlen = table->maxlen;
2860 if (copy_from_user(table->data, newval, newlen))
2866 /* The generic string strategy routine: */
2867 int sysctl_string(struct ctl_table *table,
2868 void __user *oldval, size_t __user *oldlenp,
2869 void __user *newval, size_t newlen)
2871 if (!table->data || !table->maxlen)
2874 if (oldval && oldlenp) {
2876 if (get_user(bufsize, oldlenp))
2879 size_t len = strlen(table->data), copied;
2881 /* This shouldn't trigger for a well-formed sysctl */
2882 if (len > table->maxlen)
2883 len = table->maxlen;
2885 /* Copy up to a max of bufsize-1 bytes of the string */
2886 copied = (len >= bufsize) ? bufsize - 1 : len;
2888 if (copy_to_user(oldval, table->data, copied) ||
2889 put_user(0, (char __user *)(oldval + copied)))
2891 if (put_user(len, oldlenp))
2895 if (newval && newlen) {
2896 size_t len = newlen;
2897 if (len > table->maxlen)
2898 len = table->maxlen;
2899 if(copy_from_user(table->data, newval, len))
2901 if (len == table->maxlen)
2903 ((char *) table->data)[len] = 0;
2909 * This function makes sure that all of the integers in the vector
2910 * are between the minimum and maximum values given in the arrays
2911 * table->extra1 and table->extra2, respectively.
2913 int sysctl_intvec(struct ctl_table *table,
2914 void __user *oldval, size_t __user *oldlenp,
2915 void __user *newval, size_t newlen)
2918 if (newval && newlen) {
2919 int __user *vec = (int __user *) newval;
2920 int *min = (int *) table->extra1;
2921 int *max = (int *) table->extra2;
2925 if (newlen % sizeof(int) != 0)
2928 if (!table->extra1 && !table->extra2)
2931 if (newlen > table->maxlen)
2932 newlen = table->maxlen;
2933 length = newlen / sizeof(int);
2935 for (i = 0; i < length; i++) {
2937 if (get_user(value, vec + i))
2939 if (min && value < min[i])
2941 if (max && value > max[i])
2948 /* Strategy function to convert jiffies to seconds */
2949 int sysctl_jiffies(struct ctl_table *table,
2950 void __user *oldval, size_t __user *oldlenp,
2951 void __user *newval, size_t newlen)
2953 if (oldval && oldlenp) {
2956 if (get_user(olen, oldlenp))
2961 if (olen < sizeof(int))
2964 val = *(int *)(table->data) / HZ;
2965 if (put_user(val, (int __user *)oldval))
2967 if (put_user(sizeof(int), oldlenp))
2971 if (newval && newlen) {
2973 if (newlen != sizeof(int))
2975 if (get_user(new, (int __user *)newval))
2977 *(int *)(table->data) = new*HZ;
2982 /* Strategy function to convert jiffies to seconds */
2983 int sysctl_ms_jiffies(struct ctl_table *table,
2984 void __user *oldval, size_t __user *oldlenp,
2985 void __user *newval, size_t newlen)
2987 if (oldval && oldlenp) {
2990 if (get_user(olen, oldlenp))
2995 if (olen < sizeof(int))
2998 val = jiffies_to_msecs(*(int *)(table->data));
2999 if (put_user(val, (int __user *)oldval))
3001 if (put_user(sizeof(int), oldlenp))
3005 if (newval && newlen) {
3007 if (newlen != sizeof(int))
3009 if (get_user(new, (int __user *)newval))
3011 *(int *)(table->data) = msecs_to_jiffies(new);
3018 #else /* CONFIG_SYSCTL_SYSCALL */
3021 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3023 struct __sysctl_args tmp;
3026 if (copy_from_user(&tmp, args, sizeof(tmp)))
3029 error = deprecated_sysctl_warning(&tmp);
3031 /* If no error reading the parameters then just -ENOSYS ... */
3038 int sysctl_data(struct ctl_table *table,
3039 void __user *oldval, size_t __user *oldlenp,
3040 void __user *newval, size_t newlen)
3045 int sysctl_string(struct ctl_table *table,
3046 void __user *oldval, size_t __user *oldlenp,
3047 void __user *newval, size_t newlen)
3052 int sysctl_intvec(struct ctl_table *table,
3053 void __user *oldval, size_t __user *oldlenp,
3054 void __user *newval, size_t newlen)
3059 int sysctl_jiffies(struct ctl_table *table,
3060 void __user *oldval, size_t __user *oldlenp,
3061 void __user *newval, size_t newlen)
3066 int sysctl_ms_jiffies(struct ctl_table *table,
3067 void __user *oldval, size_t __user *oldlenp,
3068 void __user *newval, size_t newlen)
3073 #endif /* CONFIG_SYSCTL_SYSCALL */
3075 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3077 static int msg_count;
3078 int name[CTL_MAXNAME];
3081 /* Check args->nlen. */
3082 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3085 /* Read in the sysctl name for better debug message logging */
3086 for (i = 0; i < args->nlen; i++)
3087 if (get_user(name[i], args->name + i))
3090 /* Ignore accesses to kernel.version */
3091 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3094 if (msg_count < 5) {
3097 "warning: process `%s' used the deprecated sysctl "
3098 "system call with ", current->comm);
3099 for (i = 0; i < args->nlen; i++)
3100 printk("%d.", name[i]);
3107 * No sense putting this after each symbol definition, twice,
3108 * exception granted :-)
3110 EXPORT_SYMBOL(proc_dointvec);
3111 EXPORT_SYMBOL(proc_dointvec_jiffies);
3112 EXPORT_SYMBOL(proc_dointvec_minmax);
3113 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3114 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3115 EXPORT_SYMBOL(proc_dostring);
3116 EXPORT_SYMBOL(proc_doulongvec_minmax);
3117 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3118 EXPORT_SYMBOL(register_sysctl_table);
3119 EXPORT_SYMBOL(register_sysctl_paths);
3120 EXPORT_SYMBOL(sysctl_intvec);
3121 EXPORT_SYMBOL(sysctl_jiffies);
3122 EXPORT_SYMBOL(sysctl_ms_jiffies);
3123 EXPORT_SYMBOL(sysctl_string);
3124 EXPORT_SYMBOL(sysctl_data);
3125 EXPORT_SYMBOL(unregister_sysctl_table);