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 maps_protect
;
84 extern int latencytop_enabled
;
85 extern int sysctl_nr_open_min
, sysctl_nr_open_max
;
86 #ifdef CONFIG_RCU_TORTURE_TEST
87 extern int rcutorture_runnable
;
88 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
90 /* Constants used for minimum and maximum */
91 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)
95 #ifdef CONFIG_DETECT_SOFTLOCKUP
96 static int sixty
= 60;
97 static int neg_one
= -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 extern char reboot_command
[];
123 extern int stop_a_enabled
;
124 extern int scons_pwroff
;
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
;
148 #ifdef CONFIG_RT_MUTEXES
149 extern int max_lock_depth
;
152 #ifdef CONFIG_PROC_SYSCTL
153 static int proc_do_cad_pid(struct ctl_table
*table
, int write
, struct file
*filp
,
154 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
155 static int proc_dointvec_taint(struct ctl_table
*table
, int write
, struct file
*filp
,
156 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
159 static struct ctl_table root_table
[];
160 static struct ctl_table_root sysctl_table_root
;
161 static struct ctl_table_header root_table_header
= {
162 .ctl_table
= root_table
,
163 .ctl_entry
= LIST_HEAD_INIT(sysctl_table_root
.default_set
.list
),
164 .root
= &sysctl_table_root
,
165 .set
= &sysctl_table_root
.default_set
,
167 static struct ctl_table_root sysctl_table_root
= {
168 .root_list
= LIST_HEAD_INIT(sysctl_table_root
.root_list
),
169 .default_set
.list
= LIST_HEAD_INIT(root_table_header
.ctl_entry
),
172 static struct ctl_table kern_table
[];
173 static struct ctl_table vm_table
[];
174 static struct ctl_table fs_table
[];
175 static struct ctl_table debug_table
[];
176 static struct ctl_table dev_table
[];
177 extern struct ctl_table random_table
[];
178 #ifdef CONFIG_INOTIFY_USER
179 extern struct ctl_table inotify_table
[];
182 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
183 int sysctl_legacy_va_layout
;
186 extern int prove_locking
;
187 extern int lock_stat
;
189 /* The default sysctl tables: */
191 static struct ctl_table root_table
[] = {
193 .ctl_name
= CTL_KERN
,
194 .procname
= "kernel",
211 .ctl_name
= CTL_DEBUG
,
214 .child
= debug_table
,
223 * NOTE: do not add new entries to this table unless you have read
224 * Documentation/sysctl/ctl_unnumbered.txt
229 #ifdef CONFIG_SCHED_DEBUG
230 static int min_sched_granularity_ns
= 100000; /* 100 usecs */
231 static int max_sched_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
232 static int min_wakeup_granularity_ns
; /* 0 usecs */
233 static int max_wakeup_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
236 static struct ctl_table kern_table
[] = {
237 #ifdef CONFIG_SCHED_DEBUG
239 .ctl_name
= CTL_UNNUMBERED
,
240 .procname
= "sched_min_granularity_ns",
241 .data
= &sysctl_sched_min_granularity
,
242 .maxlen
= sizeof(unsigned int),
244 .proc_handler
= &sched_nr_latency_handler
,
245 .strategy
= &sysctl_intvec
,
246 .extra1
= &min_sched_granularity_ns
,
247 .extra2
= &max_sched_granularity_ns
,
250 .ctl_name
= CTL_UNNUMBERED
,
251 .procname
= "sched_latency_ns",
252 .data
= &sysctl_sched_latency
,
253 .maxlen
= sizeof(unsigned int),
255 .proc_handler
= &sched_nr_latency_handler
,
256 .strategy
= &sysctl_intvec
,
257 .extra1
= &min_sched_granularity_ns
,
258 .extra2
= &max_sched_granularity_ns
,
261 .ctl_name
= CTL_UNNUMBERED
,
262 .procname
= "sched_wakeup_granularity_ns",
263 .data
= &sysctl_sched_wakeup_granularity
,
264 .maxlen
= sizeof(unsigned int),
266 .proc_handler
= &proc_dointvec_minmax
,
267 .strategy
= &sysctl_intvec
,
268 .extra1
= &min_wakeup_granularity_ns
,
269 .extra2
= &max_wakeup_granularity_ns
,
272 .ctl_name
= CTL_UNNUMBERED
,
273 .procname
= "sched_shares_ratelimit",
274 .data
= &sysctl_sched_shares_ratelimit
,
275 .maxlen
= sizeof(unsigned int),
277 .proc_handler
= &proc_dointvec
,
280 .ctl_name
= CTL_UNNUMBERED
,
281 .procname
= "sched_child_runs_first",
282 .data
= &sysctl_sched_child_runs_first
,
283 .maxlen
= sizeof(unsigned int),
285 .proc_handler
= &proc_dointvec
,
288 .ctl_name
= CTL_UNNUMBERED
,
289 .procname
= "sched_features",
290 .data
= &sysctl_sched_features
,
291 .maxlen
= sizeof(unsigned int),
293 .proc_handler
= &proc_dointvec
,
296 .ctl_name
= CTL_UNNUMBERED
,
297 .procname
= "sched_migration_cost",
298 .data
= &sysctl_sched_migration_cost
,
299 .maxlen
= sizeof(unsigned int),
301 .proc_handler
= &proc_dointvec
,
304 .ctl_name
= CTL_UNNUMBERED
,
305 .procname
= "sched_nr_migrate",
306 .data
= &sysctl_sched_nr_migrate
,
307 .maxlen
= sizeof(unsigned int),
309 .proc_handler
= &proc_dointvec
,
313 .ctl_name
= CTL_UNNUMBERED
,
314 .procname
= "sched_rt_period_us",
315 .data
= &sysctl_sched_rt_period
,
316 .maxlen
= sizeof(unsigned int),
318 .proc_handler
= &sched_rt_handler
,
321 .ctl_name
= CTL_UNNUMBERED
,
322 .procname
= "sched_rt_runtime_us",
323 .data
= &sysctl_sched_rt_runtime
,
324 .maxlen
= sizeof(int),
326 .proc_handler
= &sched_rt_handler
,
329 .ctl_name
= CTL_UNNUMBERED
,
330 .procname
= "sched_compat_yield",
331 .data
= &sysctl_sched_compat_yield
,
332 .maxlen
= sizeof(unsigned int),
334 .proc_handler
= &proc_dointvec
,
336 #ifdef CONFIG_PROVE_LOCKING
338 .ctl_name
= CTL_UNNUMBERED
,
339 .procname
= "prove_locking",
340 .data
= &prove_locking
,
341 .maxlen
= sizeof(int),
343 .proc_handler
= &proc_dointvec
,
346 #ifdef CONFIG_LOCK_STAT
348 .ctl_name
= CTL_UNNUMBERED
,
349 .procname
= "lock_stat",
351 .maxlen
= sizeof(int),
353 .proc_handler
= &proc_dointvec
,
357 .ctl_name
= KERN_PANIC
,
359 .data
= &panic_timeout
,
360 .maxlen
= sizeof(int),
362 .proc_handler
= &proc_dointvec
,
365 .ctl_name
= KERN_CORE_USES_PID
,
366 .procname
= "core_uses_pid",
367 .data
= &core_uses_pid
,
368 .maxlen
= sizeof(int),
370 .proc_handler
= &proc_dointvec
,
373 .ctl_name
= KERN_CORE_PATTERN
,
374 .procname
= "core_pattern",
375 .data
= core_pattern
,
376 .maxlen
= CORENAME_MAX_SIZE
,
378 .proc_handler
= &proc_dostring
,
379 .strategy
= &sysctl_string
,
381 #ifdef CONFIG_PROC_SYSCTL
383 .procname
= "tainted",
385 .maxlen
= sizeof(int),
387 .proc_handler
= &proc_dointvec_taint
,
390 #ifdef CONFIG_LATENCYTOP
392 .procname
= "latencytop",
393 .data
= &latencytop_enabled
,
394 .maxlen
= sizeof(int),
396 .proc_handler
= &proc_dointvec
,
399 #ifdef CONFIG_BLK_DEV_INITRD
401 .ctl_name
= KERN_REALROOTDEV
,
402 .procname
= "real-root-dev",
403 .data
= &real_root_dev
,
404 .maxlen
= sizeof(int),
406 .proc_handler
= &proc_dointvec
,
410 .ctl_name
= CTL_UNNUMBERED
,
411 .procname
= "print-fatal-signals",
412 .data
= &print_fatal_signals
,
413 .maxlen
= sizeof(int),
415 .proc_handler
= &proc_dointvec
,
419 .ctl_name
= KERN_SPARC_REBOOT
,
420 .procname
= "reboot-cmd",
421 .data
= reboot_command
,
424 .proc_handler
= &proc_dostring
,
425 .strategy
= &sysctl_string
,
428 .ctl_name
= KERN_SPARC_STOP_A
,
429 .procname
= "stop-a",
430 .data
= &stop_a_enabled
,
431 .maxlen
= sizeof (int),
433 .proc_handler
= &proc_dointvec
,
436 .ctl_name
= KERN_SPARC_SCONS_PWROFF
,
437 .procname
= "scons-poweroff",
438 .data
= &scons_pwroff
,
439 .maxlen
= sizeof (int),
441 .proc_handler
= &proc_dointvec
,
446 .ctl_name
= KERN_HPPA_PWRSW
,
447 .procname
= "soft-power",
448 .data
= &pwrsw_enabled
,
449 .maxlen
= sizeof (int),
451 .proc_handler
= &proc_dointvec
,
454 .ctl_name
= KERN_HPPA_UNALIGNED
,
455 .procname
= "unaligned-trap",
456 .data
= &unaligned_enabled
,
457 .maxlen
= sizeof (int),
459 .proc_handler
= &proc_dointvec
,
463 .ctl_name
= KERN_CTLALTDEL
,
464 .procname
= "ctrl-alt-del",
466 .maxlen
= sizeof(int),
468 .proc_handler
= &proc_dointvec
,
472 .ctl_name
= CTL_UNNUMBERED
,
473 .procname
= "ftrace_enabled",
474 .data
= &ftrace_enabled
,
475 .maxlen
= sizeof(int),
477 .proc_handler
= &ftrace_enable_sysctl
,
480 #ifdef CONFIG_MODULES
482 .ctl_name
= KERN_MODPROBE
,
483 .procname
= "modprobe",
484 .data
= &modprobe_path
,
485 .maxlen
= KMOD_PATH_LEN
,
487 .proc_handler
= &proc_dostring
,
488 .strategy
= &sysctl_string
,
491 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
493 .ctl_name
= KERN_HOTPLUG
,
494 .procname
= "hotplug",
495 .data
= &uevent_helper
,
496 .maxlen
= UEVENT_HELPER_PATH_LEN
,
498 .proc_handler
= &proc_dostring
,
499 .strategy
= &sysctl_string
,
502 #ifdef CONFIG_CHR_DEV_SG
504 .ctl_name
= KERN_SG_BIG_BUFF
,
505 .procname
= "sg-big-buff",
506 .data
= &sg_big_buff
,
507 .maxlen
= sizeof (int),
509 .proc_handler
= &proc_dointvec
,
512 #ifdef CONFIG_BSD_PROCESS_ACCT
514 .ctl_name
= KERN_ACCT
,
517 .maxlen
= 3*sizeof(int),
519 .proc_handler
= &proc_dointvec
,
522 #ifdef CONFIG_MAGIC_SYSRQ
524 .ctl_name
= KERN_SYSRQ
,
526 .data
= &__sysrq_enabled
,
527 .maxlen
= sizeof (int),
529 .proc_handler
= &proc_dointvec
,
532 #ifdef CONFIG_PROC_SYSCTL
534 .procname
= "cad_pid",
536 .maxlen
= sizeof (int),
538 .proc_handler
= &proc_do_cad_pid
,
542 .ctl_name
= KERN_MAX_THREADS
,
543 .procname
= "threads-max",
544 .data
= &max_threads
,
545 .maxlen
= sizeof(int),
547 .proc_handler
= &proc_dointvec
,
550 .ctl_name
= KERN_RANDOM
,
551 .procname
= "random",
553 .child
= random_table
,
556 .ctl_name
= KERN_OVERFLOWUID
,
557 .procname
= "overflowuid",
558 .data
= &overflowuid
,
559 .maxlen
= sizeof(int),
561 .proc_handler
= &proc_dointvec_minmax
,
562 .strategy
= &sysctl_intvec
,
563 .extra1
= &minolduid
,
564 .extra2
= &maxolduid
,
567 .ctl_name
= KERN_OVERFLOWGID
,
568 .procname
= "overflowgid",
569 .data
= &overflowgid
,
570 .maxlen
= sizeof(int),
572 .proc_handler
= &proc_dointvec_minmax
,
573 .strategy
= &sysctl_intvec
,
574 .extra1
= &minolduid
,
575 .extra2
= &maxolduid
,
578 #ifdef CONFIG_MATHEMU
580 .ctl_name
= KERN_IEEE_EMULATION_WARNINGS
,
581 .procname
= "ieee_emulation_warnings",
582 .data
= &sysctl_ieee_emulation_warnings
,
583 .maxlen
= sizeof(int),
585 .proc_handler
= &proc_dointvec
,
589 .ctl_name
= KERN_S390_USER_DEBUG_LOGGING
,
590 .procname
= "userprocess_debug",
591 .data
= &sysctl_userprocess_debug
,
592 .maxlen
= sizeof(int),
594 .proc_handler
= &proc_dointvec
,
598 .ctl_name
= KERN_PIDMAX
,
599 .procname
= "pid_max",
601 .maxlen
= sizeof (int),
603 .proc_handler
= &proc_dointvec_minmax
,
604 .strategy
= sysctl_intvec
,
605 .extra1
= &pid_max_min
,
606 .extra2
= &pid_max_max
,
609 .ctl_name
= KERN_PANIC_ON_OOPS
,
610 .procname
= "panic_on_oops",
611 .data
= &panic_on_oops
,
612 .maxlen
= sizeof(int),
614 .proc_handler
= &proc_dointvec
,
616 #if defined CONFIG_PRINTK
618 .ctl_name
= KERN_PRINTK
,
619 .procname
= "printk",
620 .data
= &console_loglevel
,
621 .maxlen
= 4*sizeof(int),
623 .proc_handler
= &proc_dointvec
,
626 .ctl_name
= KERN_PRINTK_RATELIMIT
,
627 .procname
= "printk_ratelimit",
628 .data
= &printk_ratelimit_state
.interval
,
629 .maxlen
= sizeof(int),
631 .proc_handler
= &proc_dointvec_jiffies
,
632 .strategy
= &sysctl_jiffies
,
635 .ctl_name
= KERN_PRINTK_RATELIMIT_BURST
,
636 .procname
= "printk_ratelimit_burst",
637 .data
= &printk_ratelimit_state
.burst
,
638 .maxlen
= sizeof(int),
640 .proc_handler
= &proc_dointvec
,
644 .ctl_name
= KERN_NGROUPS_MAX
,
645 .procname
= "ngroups_max",
646 .data
= &ngroups_max
,
647 .maxlen
= sizeof (int),
649 .proc_handler
= &proc_dointvec
,
651 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
653 .ctl_name
= KERN_UNKNOWN_NMI_PANIC
,
654 .procname
= "unknown_nmi_panic",
655 .data
= &unknown_nmi_panic
,
656 .maxlen
= sizeof (int),
658 .proc_handler
= &proc_dointvec
,
661 .procname
= "nmi_watchdog",
662 .data
= &nmi_watchdog_enabled
,
663 .maxlen
= sizeof (int),
665 .proc_handler
= &proc_nmi_enabled
,
668 #if defined(CONFIG_X86)
670 .ctl_name
= KERN_PANIC_ON_NMI
,
671 .procname
= "panic_on_unrecovered_nmi",
672 .data
= &panic_on_unrecovered_nmi
,
673 .maxlen
= sizeof(int),
675 .proc_handler
= &proc_dointvec
,
678 .ctl_name
= KERN_BOOTLOADER_TYPE
,
679 .procname
= "bootloader_type",
680 .data
= &bootloader_type
,
681 .maxlen
= sizeof (int),
683 .proc_handler
= &proc_dointvec
,
686 .ctl_name
= CTL_UNNUMBERED
,
687 .procname
= "kstack_depth_to_print",
688 .data
= &kstack_depth_to_print
,
689 .maxlen
= sizeof(int),
691 .proc_handler
= &proc_dointvec
,
694 .ctl_name
= CTL_UNNUMBERED
,
695 .procname
= "io_delay_type",
696 .data
= &io_delay_type
,
697 .maxlen
= sizeof(int),
699 .proc_handler
= &proc_dointvec
,
702 #if defined(CONFIG_MMU)
704 .ctl_name
= KERN_RANDOMIZE
,
705 .procname
= "randomize_va_space",
706 .data
= &randomize_va_space
,
707 .maxlen
= sizeof(int),
709 .proc_handler
= &proc_dointvec
,
712 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
714 .ctl_name
= KERN_SPIN_RETRY
,
715 .procname
= "spin_retry",
717 .maxlen
= sizeof (int),
719 .proc_handler
= &proc_dointvec
,
722 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
724 .procname
= "acpi_video_flags",
725 .data
= &acpi_realmode_flags
,
726 .maxlen
= sizeof (unsigned long),
728 .proc_handler
= &proc_doulongvec_minmax
,
733 .ctl_name
= KERN_IA64_UNALIGNED
,
734 .procname
= "ignore-unaligned-usertrap",
735 .data
= &no_unaligned_warning
,
736 .maxlen
= sizeof (int),
738 .proc_handler
= &proc_dointvec
,
741 #ifdef CONFIG_DETECT_SOFTLOCKUP
743 .ctl_name
= CTL_UNNUMBERED
,
744 .procname
= "softlockup_panic",
745 .data
= &softlockup_panic
,
746 .maxlen
= sizeof(int),
748 .proc_handler
= &proc_dointvec_minmax
,
749 .strategy
= &sysctl_intvec
,
754 .ctl_name
= CTL_UNNUMBERED
,
755 .procname
= "softlockup_thresh",
756 .data
= &softlockup_thresh
,
757 .maxlen
= sizeof(int),
759 .proc_handler
= &proc_dointvec_minmax
,
760 .strategy
= &sysctl_intvec
,
765 .ctl_name
= CTL_UNNUMBERED
,
766 .procname
= "hung_task_check_count",
767 .data
= &sysctl_hung_task_check_count
,
768 .maxlen
= sizeof(unsigned long),
770 .proc_handler
= &proc_doulongvec_minmax
,
771 .strategy
= &sysctl_intvec
,
774 .ctl_name
= CTL_UNNUMBERED
,
775 .procname
= "hung_task_timeout_secs",
776 .data
= &sysctl_hung_task_timeout_secs
,
777 .maxlen
= sizeof(unsigned long),
779 .proc_handler
= &proc_doulongvec_minmax
,
780 .strategy
= &sysctl_intvec
,
783 .ctl_name
= CTL_UNNUMBERED
,
784 .procname
= "hung_task_warnings",
785 .data
= &sysctl_hung_task_warnings
,
786 .maxlen
= sizeof(unsigned long),
788 .proc_handler
= &proc_doulongvec_minmax
,
789 .strategy
= &sysctl_intvec
,
794 .ctl_name
= KERN_COMPAT_LOG
,
795 .procname
= "compat-log",
797 .maxlen
= sizeof (int),
799 .proc_handler
= &proc_dointvec
,
802 #ifdef CONFIG_RT_MUTEXES
804 .ctl_name
= KERN_MAX_LOCK_DEPTH
,
805 .procname
= "max_lock_depth",
806 .data
= &max_lock_depth
,
807 .maxlen
= sizeof(int),
809 .proc_handler
= &proc_dointvec
,
812 #ifdef CONFIG_PROC_FS
814 .ctl_name
= CTL_UNNUMBERED
,
815 .procname
= "maps_protect",
816 .data
= &maps_protect
,
817 .maxlen
= sizeof(int),
819 .proc_handler
= &proc_dointvec
,
823 .ctl_name
= CTL_UNNUMBERED
,
824 .procname
= "poweroff_cmd",
825 .data
= &poweroff_cmd
,
826 .maxlen
= POWEROFF_CMD_PATH_LEN
,
828 .proc_handler
= &proc_dostring
,
829 .strategy
= &sysctl_string
,
833 .ctl_name
= CTL_UNNUMBERED
,
836 .child
= key_sysctls
,
839 #ifdef CONFIG_RCU_TORTURE_TEST
841 .ctl_name
= CTL_UNNUMBERED
,
842 .procname
= "rcutorture_runnable",
843 .data
= &rcutorture_runnable
,
844 .maxlen
= sizeof(int),
846 .proc_handler
= &proc_dointvec
,
850 * NOTE: do not add new entries to this table unless you have read
851 * Documentation/sysctl/ctl_unnumbered.txt
856 static struct ctl_table vm_table
[] = {
858 .ctl_name
= VM_OVERCOMMIT_MEMORY
,
859 .procname
= "overcommit_memory",
860 .data
= &sysctl_overcommit_memory
,
861 .maxlen
= sizeof(sysctl_overcommit_memory
),
863 .proc_handler
= &proc_dointvec
,
866 .ctl_name
= VM_PANIC_ON_OOM
,
867 .procname
= "panic_on_oom",
868 .data
= &sysctl_panic_on_oom
,
869 .maxlen
= sizeof(sysctl_panic_on_oom
),
871 .proc_handler
= &proc_dointvec
,
874 .ctl_name
= CTL_UNNUMBERED
,
875 .procname
= "oom_kill_allocating_task",
876 .data
= &sysctl_oom_kill_allocating_task
,
877 .maxlen
= sizeof(sysctl_oom_kill_allocating_task
),
879 .proc_handler
= &proc_dointvec
,
882 .ctl_name
= CTL_UNNUMBERED
,
883 .procname
= "oom_dump_tasks",
884 .data
= &sysctl_oom_dump_tasks
,
885 .maxlen
= sizeof(sysctl_oom_dump_tasks
),
887 .proc_handler
= &proc_dointvec
,
890 .ctl_name
= VM_OVERCOMMIT_RATIO
,
891 .procname
= "overcommit_ratio",
892 .data
= &sysctl_overcommit_ratio
,
893 .maxlen
= sizeof(sysctl_overcommit_ratio
),
895 .proc_handler
= &proc_dointvec
,
898 .ctl_name
= VM_PAGE_CLUSTER
,
899 .procname
= "page-cluster",
900 .data
= &page_cluster
,
901 .maxlen
= sizeof(int),
903 .proc_handler
= &proc_dointvec
,
906 .ctl_name
= VM_DIRTY_BACKGROUND
,
907 .procname
= "dirty_background_ratio",
908 .data
= &dirty_background_ratio
,
909 .maxlen
= sizeof(dirty_background_ratio
),
911 .proc_handler
= &proc_dointvec_minmax
,
912 .strategy
= &sysctl_intvec
,
914 .extra2
= &one_hundred
,
917 .ctl_name
= VM_DIRTY_RATIO
,
918 .procname
= "dirty_ratio",
919 .data
= &vm_dirty_ratio
,
920 .maxlen
= sizeof(vm_dirty_ratio
),
922 .proc_handler
= &dirty_ratio_handler
,
923 .strategy
= &sysctl_intvec
,
925 .extra2
= &one_hundred
,
928 .procname
= "dirty_writeback_centisecs",
929 .data
= &dirty_writeback_interval
,
930 .maxlen
= sizeof(dirty_writeback_interval
),
932 .proc_handler
= &dirty_writeback_centisecs_handler
,
935 .procname
= "dirty_expire_centisecs",
936 .data
= &dirty_expire_interval
,
937 .maxlen
= sizeof(dirty_expire_interval
),
939 .proc_handler
= &proc_dointvec_userhz_jiffies
,
942 .ctl_name
= VM_NR_PDFLUSH_THREADS
,
943 .procname
= "nr_pdflush_threads",
944 .data
= &nr_pdflush_threads
,
945 .maxlen
= sizeof nr_pdflush_threads
,
946 .mode
= 0444 /* read-only*/,
947 .proc_handler
= &proc_dointvec
,
950 .ctl_name
= VM_SWAPPINESS
,
951 .procname
= "swappiness",
952 .data
= &vm_swappiness
,
953 .maxlen
= sizeof(vm_swappiness
),
955 .proc_handler
= &proc_dointvec_minmax
,
956 .strategy
= &sysctl_intvec
,
958 .extra2
= &one_hundred
,
960 #ifdef CONFIG_HUGETLB_PAGE
962 .procname
= "nr_hugepages",
964 .maxlen
= sizeof(unsigned long),
966 .proc_handler
= &hugetlb_sysctl_handler
,
967 .extra1
= (void *)&hugetlb_zero
,
968 .extra2
= (void *)&hugetlb_infinity
,
971 .ctl_name
= VM_HUGETLB_GROUP
,
972 .procname
= "hugetlb_shm_group",
973 .data
= &sysctl_hugetlb_shm_group
,
974 .maxlen
= sizeof(gid_t
),
976 .proc_handler
= &proc_dointvec
,
979 .ctl_name
= CTL_UNNUMBERED
,
980 .procname
= "hugepages_treat_as_movable",
981 .data
= &hugepages_treat_as_movable
,
982 .maxlen
= sizeof(int),
984 .proc_handler
= &hugetlb_treat_movable_handler
,
987 .ctl_name
= CTL_UNNUMBERED
,
988 .procname
= "nr_overcommit_hugepages",
990 .maxlen
= sizeof(unsigned long),
992 .proc_handler
= &hugetlb_overcommit_handler
,
993 .extra1
= (void *)&hugetlb_zero
,
994 .extra2
= (void *)&hugetlb_infinity
,
998 .ctl_name
= VM_LOWMEM_RESERVE_RATIO
,
999 .procname
= "lowmem_reserve_ratio",
1000 .data
= &sysctl_lowmem_reserve_ratio
,
1001 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
1003 .proc_handler
= &lowmem_reserve_ratio_sysctl_handler
,
1004 .strategy
= &sysctl_intvec
,
1007 .ctl_name
= VM_DROP_PAGECACHE
,
1008 .procname
= "drop_caches",
1009 .data
= &sysctl_drop_caches
,
1010 .maxlen
= sizeof(int),
1012 .proc_handler
= drop_caches_sysctl_handler
,
1013 .strategy
= &sysctl_intvec
,
1016 .ctl_name
= VM_MIN_FREE_KBYTES
,
1017 .procname
= "min_free_kbytes",
1018 .data
= &min_free_kbytes
,
1019 .maxlen
= sizeof(min_free_kbytes
),
1021 .proc_handler
= &min_free_kbytes_sysctl_handler
,
1022 .strategy
= &sysctl_intvec
,
1026 .ctl_name
= VM_PERCPU_PAGELIST_FRACTION
,
1027 .procname
= "percpu_pagelist_fraction",
1028 .data
= &percpu_pagelist_fraction
,
1029 .maxlen
= sizeof(percpu_pagelist_fraction
),
1031 .proc_handler
= &percpu_pagelist_fraction_sysctl_handler
,
1032 .strategy
= &sysctl_intvec
,
1033 .extra1
= &min_percpu_pagelist_fract
,
1037 .ctl_name
= VM_MAX_MAP_COUNT
,
1038 .procname
= "max_map_count",
1039 .data
= &sysctl_max_map_count
,
1040 .maxlen
= sizeof(sysctl_max_map_count
),
1042 .proc_handler
= &proc_dointvec
1046 .ctl_name
= VM_LAPTOP_MODE
,
1047 .procname
= "laptop_mode",
1048 .data
= &laptop_mode
,
1049 .maxlen
= sizeof(laptop_mode
),
1051 .proc_handler
= &proc_dointvec_jiffies
,
1052 .strategy
= &sysctl_jiffies
,
1055 .ctl_name
= VM_BLOCK_DUMP
,
1056 .procname
= "block_dump",
1057 .data
= &block_dump
,
1058 .maxlen
= sizeof(block_dump
),
1060 .proc_handler
= &proc_dointvec
,
1061 .strategy
= &sysctl_intvec
,
1065 .ctl_name
= VM_VFS_CACHE_PRESSURE
,
1066 .procname
= "vfs_cache_pressure",
1067 .data
= &sysctl_vfs_cache_pressure
,
1068 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
1070 .proc_handler
= &proc_dointvec
,
1071 .strategy
= &sysctl_intvec
,
1074 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1076 .ctl_name
= VM_LEGACY_VA_LAYOUT
,
1077 .procname
= "legacy_va_layout",
1078 .data
= &sysctl_legacy_va_layout
,
1079 .maxlen
= sizeof(sysctl_legacy_va_layout
),
1081 .proc_handler
= &proc_dointvec
,
1082 .strategy
= &sysctl_intvec
,
1088 .ctl_name
= VM_ZONE_RECLAIM_MODE
,
1089 .procname
= "zone_reclaim_mode",
1090 .data
= &zone_reclaim_mode
,
1091 .maxlen
= sizeof(zone_reclaim_mode
),
1093 .proc_handler
= &proc_dointvec
,
1094 .strategy
= &sysctl_intvec
,
1098 .ctl_name
= VM_MIN_UNMAPPED
,
1099 .procname
= "min_unmapped_ratio",
1100 .data
= &sysctl_min_unmapped_ratio
,
1101 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1103 .proc_handler
= &sysctl_min_unmapped_ratio_sysctl_handler
,
1104 .strategy
= &sysctl_intvec
,
1106 .extra2
= &one_hundred
,
1109 .ctl_name
= VM_MIN_SLAB
,
1110 .procname
= "min_slab_ratio",
1111 .data
= &sysctl_min_slab_ratio
,
1112 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1114 .proc_handler
= &sysctl_min_slab_ratio_sysctl_handler
,
1115 .strategy
= &sysctl_intvec
,
1117 .extra2
= &one_hundred
,
1122 .ctl_name
= CTL_UNNUMBERED
,
1123 .procname
= "stat_interval",
1124 .data
= &sysctl_stat_interval
,
1125 .maxlen
= sizeof(sysctl_stat_interval
),
1127 .proc_handler
= &proc_dointvec_jiffies
,
1128 .strategy
= &sysctl_jiffies
,
1131 #ifdef CONFIG_SECURITY
1133 .ctl_name
= CTL_UNNUMBERED
,
1134 .procname
= "mmap_min_addr",
1135 .data
= &mmap_min_addr
,
1136 .maxlen
= sizeof(unsigned long),
1138 .proc_handler
= &proc_doulongvec_minmax
,
1143 .ctl_name
= CTL_UNNUMBERED
,
1144 .procname
= "numa_zonelist_order",
1145 .data
= &numa_zonelist_order
,
1146 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1148 .proc_handler
= &numa_zonelist_order_handler
,
1149 .strategy
= &sysctl_string
,
1152 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1153 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1155 .ctl_name
= VM_VDSO_ENABLED
,
1156 .procname
= "vdso_enabled",
1157 .data
= &vdso_enabled
,
1158 .maxlen
= sizeof(vdso_enabled
),
1160 .proc_handler
= &proc_dointvec
,
1161 .strategy
= &sysctl_intvec
,
1165 #ifdef CONFIG_HIGHMEM
1167 .ctl_name
= CTL_UNNUMBERED
,
1168 .procname
= "highmem_is_dirtyable",
1169 .data
= &vm_highmem_is_dirtyable
,
1170 .maxlen
= sizeof(vm_highmem_is_dirtyable
),
1172 .proc_handler
= &proc_dointvec_minmax
,
1173 .strategy
= &sysctl_intvec
,
1179 * NOTE: do not add new entries to this table unless you have read
1180 * Documentation/sysctl/ctl_unnumbered.txt
1185 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1186 static struct ctl_table binfmt_misc_table
[] = {
1191 static struct ctl_table fs_table
[] = {
1193 .ctl_name
= FS_NRINODE
,
1194 .procname
= "inode-nr",
1195 .data
= &inodes_stat
,
1196 .maxlen
= 2*sizeof(int),
1198 .proc_handler
= &proc_dointvec
,
1201 .ctl_name
= FS_STATINODE
,
1202 .procname
= "inode-state",
1203 .data
= &inodes_stat
,
1204 .maxlen
= 7*sizeof(int),
1206 .proc_handler
= &proc_dointvec
,
1209 .procname
= "file-nr",
1210 .data
= &files_stat
,
1211 .maxlen
= 3*sizeof(int),
1213 .proc_handler
= &proc_nr_files
,
1216 .ctl_name
= FS_MAXFILE
,
1217 .procname
= "file-max",
1218 .data
= &files_stat
.max_files
,
1219 .maxlen
= sizeof(int),
1221 .proc_handler
= &proc_dointvec
,
1224 .ctl_name
= CTL_UNNUMBERED
,
1225 .procname
= "nr_open",
1226 .data
= &sysctl_nr_open
,
1227 .maxlen
= sizeof(int),
1229 .proc_handler
= &proc_dointvec_minmax
,
1230 .extra1
= &sysctl_nr_open_min
,
1231 .extra2
= &sysctl_nr_open_max
,
1234 .ctl_name
= FS_DENTRY
,
1235 .procname
= "dentry-state",
1236 .data
= &dentry_stat
,
1237 .maxlen
= 6*sizeof(int),
1239 .proc_handler
= &proc_dointvec
,
1242 .ctl_name
= FS_OVERFLOWUID
,
1243 .procname
= "overflowuid",
1244 .data
= &fs_overflowuid
,
1245 .maxlen
= sizeof(int),
1247 .proc_handler
= &proc_dointvec_minmax
,
1248 .strategy
= &sysctl_intvec
,
1249 .extra1
= &minolduid
,
1250 .extra2
= &maxolduid
,
1253 .ctl_name
= FS_OVERFLOWGID
,
1254 .procname
= "overflowgid",
1255 .data
= &fs_overflowgid
,
1256 .maxlen
= sizeof(int),
1258 .proc_handler
= &proc_dointvec_minmax
,
1259 .strategy
= &sysctl_intvec
,
1260 .extra1
= &minolduid
,
1261 .extra2
= &maxolduid
,
1264 .ctl_name
= FS_LEASES
,
1265 .procname
= "leases-enable",
1266 .data
= &leases_enable
,
1267 .maxlen
= sizeof(int),
1269 .proc_handler
= &proc_dointvec
,
1271 #ifdef CONFIG_DNOTIFY
1273 .ctl_name
= FS_DIR_NOTIFY
,
1274 .procname
= "dir-notify-enable",
1275 .data
= &dir_notify_enable
,
1276 .maxlen
= sizeof(int),
1278 .proc_handler
= &proc_dointvec
,
1283 .ctl_name
= FS_LEASE_TIME
,
1284 .procname
= "lease-break-time",
1285 .data
= &lease_break_time
,
1286 .maxlen
= sizeof(int),
1288 .proc_handler
= &proc_dointvec_minmax
,
1289 .strategy
= &sysctl_intvec
,
1294 .procname
= "aio-nr",
1296 .maxlen
= sizeof(aio_nr
),
1298 .proc_handler
= &proc_doulongvec_minmax
,
1301 .procname
= "aio-max-nr",
1302 .data
= &aio_max_nr
,
1303 .maxlen
= sizeof(aio_max_nr
),
1305 .proc_handler
= &proc_doulongvec_minmax
,
1307 #ifdef CONFIG_INOTIFY_USER
1309 .ctl_name
= FS_INOTIFY
,
1310 .procname
= "inotify",
1312 .child
= inotify_table
,
1317 .ctl_name
= KERN_SETUID_DUMPABLE
,
1318 .procname
= "suid_dumpable",
1319 .data
= &suid_dumpable
,
1320 .maxlen
= sizeof(int),
1322 .proc_handler
= &proc_dointvec
,
1324 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1326 .ctl_name
= CTL_UNNUMBERED
,
1327 .procname
= "binfmt_misc",
1329 .child
= binfmt_misc_table
,
1333 * NOTE: do not add new entries to this table unless you have read
1334 * Documentation/sysctl/ctl_unnumbered.txt
1339 static struct ctl_table debug_table
[] = {
1340 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1342 .ctl_name
= CTL_UNNUMBERED
,
1343 .procname
= "exception-trace",
1344 .data
= &show_unhandled_signals
,
1345 .maxlen
= sizeof(int),
1347 .proc_handler
= proc_dointvec
1353 static struct ctl_table dev_table
[] = {
1357 static DEFINE_SPINLOCK(sysctl_lock
);
1359 /* called under sysctl_lock */
1360 static int use_table(struct ctl_table_header
*p
)
1362 if (unlikely(p
->unregistering
))
1368 /* called under sysctl_lock */
1369 static void unuse_table(struct ctl_table_header
*p
)
1372 if (unlikely(p
->unregistering
))
1373 complete(p
->unregistering
);
1376 /* called under sysctl_lock, will reacquire if has to wait */
1377 static void start_unregistering(struct ctl_table_header
*p
)
1380 * if p->used is 0, nobody will ever touch that entry again;
1381 * we'll eliminate all paths to it before dropping sysctl_lock
1383 if (unlikely(p
->used
)) {
1384 struct completion wait
;
1385 init_completion(&wait
);
1386 p
->unregistering
= &wait
;
1387 spin_unlock(&sysctl_lock
);
1388 wait_for_completion(&wait
);
1389 spin_lock(&sysctl_lock
);
1392 * do not remove from the list until nobody holds it; walking the
1393 * list in do_sysctl() relies on that.
1395 list_del_init(&p
->ctl_entry
);
1398 void sysctl_head_finish(struct ctl_table_header
*head
)
1402 spin_lock(&sysctl_lock
);
1404 spin_unlock(&sysctl_lock
);
1407 static struct ctl_table_set
*
1408 lookup_header_set(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1410 struct ctl_table_set
*set
= &root
->default_set
;
1412 set
= root
->lookup(root
, namespaces
);
1416 static struct list_head
*
1417 lookup_header_list(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1419 struct ctl_table_set
*set
= lookup_header_set(root
, namespaces
);
1423 struct ctl_table_header
*__sysctl_head_next(struct nsproxy
*namespaces
,
1424 struct ctl_table_header
*prev
)
1426 struct ctl_table_root
*root
;
1427 struct list_head
*header_list
;
1428 struct ctl_table_header
*head
;
1429 struct list_head
*tmp
;
1431 spin_lock(&sysctl_lock
);
1434 tmp
= &prev
->ctl_entry
;
1438 tmp
= &root_table_header
.ctl_entry
;
1440 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1442 if (!use_table(head
))
1444 spin_unlock(&sysctl_lock
);
1449 header_list
= lookup_header_list(root
, namespaces
);
1450 if (tmp
!= header_list
)
1454 root
= list_entry(root
->root_list
.next
,
1455 struct ctl_table_root
, root_list
);
1456 if (root
== &sysctl_table_root
)
1458 header_list
= lookup_header_list(root
, namespaces
);
1459 } while (list_empty(header_list
));
1460 tmp
= header_list
->next
;
1463 spin_unlock(&sysctl_lock
);
1467 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1469 return __sysctl_head_next(current
->nsproxy
, prev
);
1472 void register_sysctl_root(struct ctl_table_root
*root
)
1474 spin_lock(&sysctl_lock
);
1475 list_add_tail(&root
->root_list
, &sysctl_table_root
.root_list
);
1476 spin_unlock(&sysctl_lock
);
1479 #ifdef CONFIG_SYSCTL_SYSCALL
1480 /* Perform the actual read/write of a sysctl table entry. */
1481 static int do_sysctl_strategy(struct ctl_table_root
*root
,
1482 struct ctl_table
*table
,
1483 int __user
*name
, int nlen
,
1484 void __user
*oldval
, size_t __user
*oldlenp
,
1485 void __user
*newval
, size_t newlen
)
1493 if (sysctl_perm(root
, table
, op
))
1496 if (table
->strategy
) {
1497 rc
= table
->strategy(table
, name
, nlen
, oldval
, oldlenp
,
1505 /* If there is no strategy routine, or if the strategy returns
1506 * zero, proceed with automatic r/w */
1507 if (table
->data
&& table
->maxlen
) {
1508 rc
= sysctl_data(table
, name
, nlen
, oldval
, oldlenp
,
1516 static int parse_table(int __user
*name
, int nlen
,
1517 void __user
*oldval
, size_t __user
*oldlenp
,
1518 void __user
*newval
, size_t newlen
,
1519 struct ctl_table_root
*root
,
1520 struct ctl_table
*table
)
1526 if (get_user(n
, name
))
1528 for ( ; table
->ctl_name
|| table
->procname
; table
++) {
1529 if (!table
->ctl_name
)
1531 if (n
== table
->ctl_name
) {
1534 if (sysctl_perm(root
, table
, 001))
1538 table
= table
->child
;
1541 error
= do_sysctl_strategy(root
, table
, name
, nlen
,
1550 int do_sysctl(int __user
*name
, int nlen
, void __user
*oldval
, size_t __user
*oldlenp
,
1551 void __user
*newval
, size_t newlen
)
1553 struct ctl_table_header
*head
;
1554 int error
= -ENOTDIR
;
1556 if (nlen
<= 0 || nlen
>= CTL_MAXNAME
)
1560 if (!oldlenp
|| get_user(old_len
, oldlenp
))
1564 for (head
= sysctl_head_next(NULL
); head
;
1565 head
= sysctl_head_next(head
)) {
1566 error
= parse_table(name
, nlen
, oldval
, oldlenp
,
1568 head
->root
, head
->ctl_table
);
1569 if (error
!= -ENOTDIR
) {
1570 sysctl_head_finish(head
);
1577 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
1579 struct __sysctl_args tmp
;
1582 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
1585 error
= deprecated_sysctl_warning(&tmp
);
1590 error
= do_sysctl(tmp
.name
, tmp
.nlen
, tmp
.oldval
, tmp
.oldlenp
,
1591 tmp
.newval
, tmp
.newlen
);
1596 #endif /* CONFIG_SYSCTL_SYSCALL */
1599 * sysctl_perm does NOT grant the superuser all rights automatically, because
1600 * some sysctl variables are readonly even to root.
1603 static int test_perm(int mode
, int op
)
1607 else if (in_egroup_p(0))
1609 if ((mode
& op
& 0007) == op
)
1614 int sysctl_perm(struct ctl_table_root
*root
, struct ctl_table
*table
, int op
)
1619 error
= security_sysctl(table
, op
);
1623 if (root
->permissions
)
1624 mode
= root
->permissions(root
, current
->nsproxy
, table
);
1628 return test_perm(mode
, op
);
1631 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1633 for (; table
->ctl_name
|| table
->procname
; table
++) {
1634 table
->parent
= parent
;
1636 sysctl_set_parent(table
, table
->child
);
1640 static __init
int sysctl_init(void)
1642 sysctl_set_parent(NULL
, root_table
);
1643 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1646 err
= sysctl_check_table(current
->nsproxy
, root_table
);
1652 core_initcall(sysctl_init
);
1655 * __register_sysctl_paths - register a sysctl hierarchy
1656 * @root: List of sysctl headers to register on
1657 * @namespaces: Data to compute which lists of sysctl entries are visible
1658 * @path: The path to the directory the sysctl table is in.
1659 * @table: the top-level table structure
1661 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1662 * array. A completely 0 filled entry terminates the table.
1664 * The members of the &struct ctl_table structure are used as follows:
1666 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1667 * must be unique within that level of sysctl
1669 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1670 * enter a sysctl file
1672 * data - a pointer to data for use by proc_handler
1674 * maxlen - the maximum size in bytes of the data
1676 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1678 * child - a pointer to the child sysctl table if this entry is a directory, or
1681 * proc_handler - the text handler routine (described below)
1683 * strategy - the strategy routine (described below)
1685 * de - for internal use by the sysctl routines
1687 * extra1, extra2 - extra pointers usable by the proc handler routines
1689 * Leaf nodes in the sysctl tree will be represented by a single file
1690 * under /proc; non-leaf nodes will be represented by directories.
1692 * sysctl(2) can automatically manage read and write requests through
1693 * the sysctl table. The data and maxlen fields of the ctl_table
1694 * struct enable minimal validation of the values being written to be
1695 * performed, and the mode field allows minimal authentication.
1697 * More sophisticated management can be enabled by the provision of a
1698 * strategy routine with the table entry. This will be called before
1699 * any automatic read or write of the data is performed.
1701 * The strategy routine may return
1703 * < 0 - Error occurred (error is passed to user process)
1705 * 0 - OK - proceed with automatic read or write.
1707 * > 0 - OK - read or write has been done by the strategy routine, so
1708 * return immediately.
1710 * There must be a proc_handler routine for any terminal nodes
1711 * mirrored under /proc/sys (non-terminals are handled by a built-in
1712 * directory handler). Several default handlers are available to
1713 * cover common cases -
1715 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1716 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1717 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1719 * It is the handler's job to read the input buffer from user memory
1720 * and process it. The handler should return 0 on success.
1722 * This routine returns %NULL on a failure to register, and a pointer
1723 * to the table header on success.
1725 struct ctl_table_header
*__register_sysctl_paths(
1726 struct ctl_table_root
*root
,
1727 struct nsproxy
*namespaces
,
1728 const struct ctl_path
*path
, struct ctl_table
*table
)
1730 struct ctl_table_header
*header
;
1731 struct ctl_table
*new, **prevp
;
1732 unsigned int n
, npath
;
1734 /* Count the path components */
1735 for (npath
= 0; path
[npath
].ctl_name
|| path
[npath
].procname
; ++npath
)
1739 * For each path component, allocate a 2-element ctl_table array.
1740 * The first array element will be filled with the sysctl entry
1741 * for this, the second will be the sentinel (ctl_name == 0).
1743 * We allocate everything in one go so that we don't have to
1744 * worry about freeing additional memory in unregister_sysctl_table.
1746 header
= kzalloc(sizeof(struct ctl_table_header
) +
1747 (2 * npath
* sizeof(struct ctl_table
)), GFP_KERNEL
);
1751 new = (struct ctl_table
*) (header
+ 1);
1753 /* Now connect the dots */
1754 prevp
= &header
->ctl_table
;
1755 for (n
= 0; n
< npath
; ++n
, ++path
) {
1756 /* Copy the procname */
1757 new->procname
= path
->procname
;
1758 new->ctl_name
= path
->ctl_name
;
1762 prevp
= &new->child
;
1767 header
->ctl_table_arg
= table
;
1769 INIT_LIST_HEAD(&header
->ctl_entry
);
1771 header
->unregistering
= NULL
;
1772 header
->root
= root
;
1773 sysctl_set_parent(NULL
, header
->ctl_table
);
1774 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1775 if (sysctl_check_table(namespaces
, header
->ctl_table
)) {
1780 spin_lock(&sysctl_lock
);
1781 header
->set
= lookup_header_set(root
, namespaces
);
1782 list_add_tail(&header
->ctl_entry
, &header
->set
->list
);
1783 spin_unlock(&sysctl_lock
);
1789 * register_sysctl_table_path - register a sysctl table hierarchy
1790 * @path: The path to the directory the sysctl table is in.
1791 * @table: the top-level table structure
1793 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1794 * array. A completely 0 filled entry terminates the table.
1796 * See __register_sysctl_paths for more details.
1798 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1799 struct ctl_table
*table
)
1801 return __register_sysctl_paths(&sysctl_table_root
, current
->nsproxy
,
1806 * register_sysctl_table - register a sysctl table hierarchy
1807 * @table: the top-level table structure
1809 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1810 * array. A completely 0 filled entry terminates the table.
1812 * See register_sysctl_paths for more details.
1814 struct ctl_table_header
*register_sysctl_table(struct ctl_table
*table
)
1816 static const struct ctl_path null_path
[] = { {} };
1818 return register_sysctl_paths(null_path
, table
);
1822 * unregister_sysctl_table - unregister a sysctl table hierarchy
1823 * @header: the header returned from register_sysctl_table
1825 * Unregisters the sysctl table and all children. proc entries may not
1826 * actually be removed until they are no longer used by anyone.
1828 void unregister_sysctl_table(struct ctl_table_header
* header
)
1835 spin_lock(&sysctl_lock
);
1836 start_unregistering(header
);
1837 spin_unlock(&sysctl_lock
);
1841 void setup_sysctl_set(struct ctl_table_set
*p
,
1842 struct ctl_table_set
*parent
,
1843 int (*is_seen
)(struct ctl_table_set
*))
1845 INIT_LIST_HEAD(&p
->list
);
1846 p
->parent
= parent
? parent
: &sysctl_table_root
.default_set
;
1847 p
->is_seen
= is_seen
;
1850 #else /* !CONFIG_SYSCTL */
1851 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
1856 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1857 struct ctl_table
*table
)
1862 void unregister_sysctl_table(struct ctl_table_header
* table
)
1866 void setup_sysctl_set(struct ctl_table_set
*p
,
1867 struct ctl_table_set
*parent
,
1868 int (*is_seen
)(struct ctl_table_set
*))
1872 #endif /* CONFIG_SYSCTL */
1878 #ifdef CONFIG_PROC_SYSCTL
1880 static int _proc_do_string(void* data
, int maxlen
, int write
,
1881 struct file
*filp
, void __user
*buffer
,
1882 size_t *lenp
, loff_t
*ppos
)
1888 if (!data
|| !maxlen
|| !*lenp
) {
1896 while (len
< *lenp
) {
1897 if (get_user(c
, p
++))
1899 if (c
== 0 || c
== '\n')
1905 if(copy_from_user(data
, buffer
, len
))
1907 ((char *) data
)[len
] = 0;
1925 if(copy_to_user(buffer
, data
, len
))
1928 if(put_user('\n', ((char __user
*) buffer
) + len
))
1939 * proc_dostring - read a string sysctl
1940 * @table: the sysctl table
1941 * @write: %TRUE if this is a write to the sysctl file
1942 * @filp: the file structure
1943 * @buffer: the user buffer
1944 * @lenp: the size of the user buffer
1945 * @ppos: file position
1947 * Reads/writes a string from/to the user buffer. If the kernel
1948 * buffer provided is not large enough to hold the string, the
1949 * string is truncated. The copied string is %NULL-terminated.
1950 * If the string is being read by the user process, it is copied
1951 * and a newline '\n' is added. It is truncated if the buffer is
1954 * Returns 0 on success.
1956 int proc_dostring(struct ctl_table
*table
, int write
, struct file
*filp
,
1957 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1959 return _proc_do_string(table
->data
, table
->maxlen
, write
, filp
,
1960 buffer
, lenp
, ppos
);
1964 static int do_proc_dointvec_conv(int *negp
, unsigned long *lvalp
,
1966 int write
, void *data
)
1969 *valp
= *negp
? -*lvalp
: *lvalp
;
1974 *lvalp
= (unsigned long)-val
;
1977 *lvalp
= (unsigned long)val
;
1983 static int __do_proc_dointvec(void *tbl_data
, struct ctl_table
*table
,
1984 int write
, struct file
*filp
, void __user
*buffer
,
1985 size_t *lenp
, loff_t
*ppos
,
1986 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1987 int write
, void *data
),
1990 #define TMPBUFLEN 21
1991 int *i
, vleft
, first
=1, neg
, val
;
1995 char buf
[TMPBUFLEN
], *p
;
1996 char __user
*s
= buffer
;
1998 if (!tbl_data
|| !table
->maxlen
|| !*lenp
||
1999 (*ppos
&& !write
)) {
2004 i
= (int *) tbl_data
;
2005 vleft
= table
->maxlen
/ sizeof(*i
);
2009 conv
= do_proc_dointvec_conv
;
2011 for (; left
&& vleft
--; i
++, first
=0) {
2026 if (len
> sizeof(buf
) - 1)
2027 len
= sizeof(buf
) - 1;
2028 if (copy_from_user(buf
, s
, len
))
2032 if (*p
== '-' && left
> 1) {
2036 if (*p
< '0' || *p
> '9')
2039 lval
= simple_strtoul(p
, &p
, 0);
2042 if ((len
< left
) && *p
&& !isspace(*p
))
2049 if (conv(&neg
, &lval
, i
, 1, data
))
2056 if (conv(&neg
, &lval
, i
, 0, data
))
2059 sprintf(p
, "%s%lu", neg
? "-" : "", lval
);
2063 if(copy_to_user(s
, buf
, len
))
2070 if (!write
&& !first
&& left
) {
2071 if(put_user('\n', s
))
2078 if (get_user(c
, s
++))
2093 static int do_proc_dointvec(struct ctl_table
*table
, int write
, struct file
*filp
,
2094 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
2095 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
2096 int write
, void *data
),
2099 return __do_proc_dointvec(table
->data
, table
, write
, filp
,
2100 buffer
, lenp
, ppos
, conv
, data
);
2104 * proc_dointvec - read a vector of integers
2105 * @table: the sysctl table
2106 * @write: %TRUE if this is a write to the sysctl file
2107 * @filp: the file structure
2108 * @buffer: the user buffer
2109 * @lenp: the size of the user buffer
2110 * @ppos: file position
2112 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2113 * values from/to the user buffer, treated as an ASCII string.
2115 * Returns 0 on success.
2117 int proc_dointvec(struct ctl_table
*table
, int write
, struct file
*filp
,
2118 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2120 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2128 static int do_proc_dointvec_bset_conv(int *negp
, unsigned long *lvalp
,
2130 int write
, void *data
)
2132 int op
= *(int *)data
;
2134 int val
= *negp
? -*lvalp
: *lvalp
;
2136 case OP_SET
: *valp
= val
; break;
2137 case OP_AND
: *valp
&= val
; break;
2138 case OP_OR
: *valp
|= val
; break;
2144 *lvalp
= (unsigned long)-val
;
2147 *lvalp
= (unsigned long)val
;
2154 * Taint values can only be increased
2156 static int proc_dointvec_taint(struct ctl_table
*table
, int write
, struct file
*filp
,
2157 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2161 if (write
&& !capable(CAP_SYS_ADMIN
))
2165 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2166 do_proc_dointvec_bset_conv
,&op
);
2169 struct do_proc_dointvec_minmax_conv_param
{
2174 static int do_proc_dointvec_minmax_conv(int *negp
, unsigned long *lvalp
,
2176 int write
, void *data
)
2178 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
2180 int val
= *negp
? -*lvalp
: *lvalp
;
2181 if ((param
->min
&& *param
->min
> val
) ||
2182 (param
->max
&& *param
->max
< val
))
2189 *lvalp
= (unsigned long)-val
;
2192 *lvalp
= (unsigned long)val
;
2199 * proc_dointvec_minmax - read a vector of integers with min/max values
2200 * @table: the sysctl table
2201 * @write: %TRUE if this is a write to the sysctl file
2202 * @filp: the file structure
2203 * @buffer: the user buffer
2204 * @lenp: the size of the user buffer
2205 * @ppos: file position
2207 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2208 * values from/to the user buffer, treated as an ASCII string.
2210 * This routine will ensure the values are within the range specified by
2211 * table->extra1 (min) and table->extra2 (max).
2213 * Returns 0 on success.
2215 int proc_dointvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2216 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2218 struct do_proc_dointvec_minmax_conv_param param
= {
2219 .min
= (int *) table
->extra1
,
2220 .max
= (int *) table
->extra2
,
2222 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
2223 do_proc_dointvec_minmax_conv
, ¶m
);
2226 static int __do_proc_doulongvec_minmax(void *data
, struct ctl_table
*table
, int write
,
2228 void __user
*buffer
,
2229 size_t *lenp
, loff_t
*ppos
,
2230 unsigned long convmul
,
2231 unsigned long convdiv
)
2233 #define TMPBUFLEN 21
2234 unsigned long *i
, *min
, *max
, val
;
2235 int vleft
, first
=1, neg
;
2237 char buf
[TMPBUFLEN
], *p
;
2238 char __user
*s
= buffer
;
2240 if (!data
|| !table
->maxlen
|| !*lenp
||
2241 (*ppos
&& !write
)) {
2246 i
= (unsigned long *) data
;
2247 min
= (unsigned long *) table
->extra1
;
2248 max
= (unsigned long *) table
->extra2
;
2249 vleft
= table
->maxlen
/ sizeof(unsigned long);
2252 for (; left
&& vleft
--; i
++, min
++, max
++, first
=0) {
2267 if (len
> TMPBUFLEN
-1)
2269 if (copy_from_user(buf
, s
, len
))
2273 if (*p
== '-' && left
> 1) {
2277 if (*p
< '0' || *p
> '9')
2279 val
= simple_strtoul(p
, &p
, 0) * convmul
/ convdiv
;
2281 if ((len
< left
) && *p
&& !isspace(*p
))
2290 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2297 sprintf(p
, "%lu", convdiv
* (*i
) / convmul
);
2301 if(copy_to_user(s
, buf
, len
))
2308 if (!write
&& !first
&& left
) {
2309 if(put_user('\n', s
))
2316 if (get_user(c
, s
++))
2331 static int do_proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2333 void __user
*buffer
,
2334 size_t *lenp
, loff_t
*ppos
,
2335 unsigned long convmul
,
2336 unsigned long convdiv
)
2338 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2339 filp
, buffer
, lenp
, ppos
, convmul
, convdiv
);
2343 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2344 * @table: the sysctl table
2345 * @write: %TRUE if this is a write to the sysctl file
2346 * @filp: the file structure
2347 * @buffer: the user buffer
2348 * @lenp: the size of the user buffer
2349 * @ppos: file position
2351 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2352 * values from/to the user buffer, treated as an ASCII string.
2354 * This routine will ensure the values are within the range specified by
2355 * table->extra1 (min) and table->extra2 (max).
2357 * Returns 0 on success.
2359 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2360 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2362 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
, lenp
, ppos
, 1l, 1l);
2366 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2367 * @table: the sysctl table
2368 * @write: %TRUE if this is a write to the sysctl file
2369 * @filp: the file structure
2370 * @buffer: the user buffer
2371 * @lenp: the size of the user buffer
2372 * @ppos: file position
2374 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2375 * values from/to the user buffer, treated as an ASCII string. The values
2376 * are treated as milliseconds, and converted to jiffies when they are stored.
2378 * This routine will ensure the values are within the range specified by
2379 * table->extra1 (min) and table->extra2 (max).
2381 * Returns 0 on success.
2383 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2385 void __user
*buffer
,
2386 size_t *lenp
, loff_t
*ppos
)
2388 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
,
2389 lenp
, ppos
, HZ
, 1000l);
2393 static int do_proc_dointvec_jiffies_conv(int *negp
, unsigned long *lvalp
,
2395 int write
, void *data
)
2398 if (*lvalp
> LONG_MAX
/ HZ
)
2400 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2406 lval
= (unsigned long)-val
;
2409 lval
= (unsigned long)val
;
2416 static int do_proc_dointvec_userhz_jiffies_conv(int *negp
, unsigned long *lvalp
,
2418 int write
, void *data
)
2421 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2423 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2429 lval
= (unsigned long)-val
;
2432 lval
= (unsigned long)val
;
2434 *lvalp
= jiffies_to_clock_t(lval
);
2439 static int do_proc_dointvec_ms_jiffies_conv(int *negp
, unsigned long *lvalp
,
2441 int write
, void *data
)
2444 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2450 lval
= (unsigned long)-val
;
2453 lval
= (unsigned long)val
;
2455 *lvalp
= jiffies_to_msecs(lval
);
2461 * proc_dointvec_jiffies - read a vector of integers as seconds
2462 * @table: the sysctl table
2463 * @write: %TRUE if this is a write to the sysctl file
2464 * @filp: the file structure
2465 * @buffer: the user buffer
2466 * @lenp: the size of the user buffer
2467 * @ppos: file position
2469 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2470 * values from/to the user buffer, treated as an ASCII string.
2471 * The values read are assumed to be in seconds, and are converted into
2474 * Returns 0 on success.
2476 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2477 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2479 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2480 do_proc_dointvec_jiffies_conv
,NULL
);
2484 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2485 * @table: the sysctl table
2486 * @write: %TRUE if this is a write to the sysctl file
2487 * @filp: the file structure
2488 * @buffer: the user buffer
2489 * @lenp: the size of the user buffer
2490 * @ppos: pointer to the file position
2492 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2493 * values from/to the user buffer, treated as an ASCII string.
2494 * The values read are assumed to be in 1/USER_HZ seconds, and
2495 * are converted into jiffies.
2497 * Returns 0 on success.
2499 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2500 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2502 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2503 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2507 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2508 * @table: the sysctl table
2509 * @write: %TRUE if this is a write to the sysctl file
2510 * @filp: the file structure
2511 * @buffer: the user buffer
2512 * @lenp: the size of the user buffer
2513 * @ppos: file position
2514 * @ppos: the current position in the file
2516 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2517 * values from/to the user buffer, treated as an ASCII string.
2518 * The values read are assumed to be in 1/1000 seconds, and
2519 * are converted into jiffies.
2521 * Returns 0 on success.
2523 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2524 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2526 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
2527 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2530 static int proc_do_cad_pid(struct ctl_table
*table
, int write
, struct file
*filp
,
2531 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2533 struct pid
*new_pid
;
2537 tmp
= pid_vnr(cad_pid
);
2539 r
= __do_proc_dointvec(&tmp
, table
, write
, filp
, buffer
,
2540 lenp
, ppos
, NULL
, NULL
);
2544 new_pid
= find_get_pid(tmp
);
2548 put_pid(xchg(&cad_pid
, new_pid
));
2552 #else /* CONFIG_PROC_FS */
2554 int proc_dostring(struct ctl_table
*table
, int write
, struct file
*filp
,
2555 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2560 int proc_dointvec(struct ctl_table
*table
, int write
, struct file
*filp
,
2561 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2566 int proc_dointvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2567 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2572 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2573 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2578 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2579 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2584 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2585 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2590 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2591 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2596 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2598 void __user
*buffer
,
2599 size_t *lenp
, loff_t
*ppos
)
2605 #endif /* CONFIG_PROC_FS */
2608 #ifdef CONFIG_SYSCTL_SYSCALL
2610 * General sysctl support routines
2613 /* The generic sysctl data routine (used if no strategy routine supplied) */
2614 int sysctl_data(struct ctl_table
*table
, int __user
*name
, int nlen
,
2615 void __user
*oldval
, size_t __user
*oldlenp
,
2616 void __user
*newval
, size_t newlen
)
2620 /* Get out of I don't have a variable */
2621 if (!table
->data
|| !table
->maxlen
)
2624 if (oldval
&& oldlenp
) {
2625 if (get_user(len
, oldlenp
))
2628 if (len
> table
->maxlen
)
2629 len
= table
->maxlen
;
2630 if (copy_to_user(oldval
, table
->data
, len
))
2632 if (put_user(len
, oldlenp
))
2637 if (newval
&& newlen
) {
2638 if (newlen
> table
->maxlen
)
2639 newlen
= table
->maxlen
;
2641 if (copy_from_user(table
->data
, newval
, newlen
))
2647 /* The generic string strategy routine: */
2648 int sysctl_string(struct ctl_table
*table
, int __user
*name
, int nlen
,
2649 void __user
*oldval
, size_t __user
*oldlenp
,
2650 void __user
*newval
, size_t newlen
)
2652 if (!table
->data
|| !table
->maxlen
)
2655 if (oldval
&& oldlenp
) {
2657 if (get_user(bufsize
, oldlenp
))
2660 size_t len
= strlen(table
->data
), copied
;
2662 /* This shouldn't trigger for a well-formed sysctl */
2663 if (len
> table
->maxlen
)
2664 len
= table
->maxlen
;
2666 /* Copy up to a max of bufsize-1 bytes of the string */
2667 copied
= (len
>= bufsize
) ? bufsize
- 1 : len
;
2669 if (copy_to_user(oldval
, table
->data
, copied
) ||
2670 put_user(0, (char __user
*)(oldval
+ copied
)))
2672 if (put_user(len
, oldlenp
))
2676 if (newval
&& newlen
) {
2677 size_t len
= newlen
;
2678 if (len
> table
->maxlen
)
2679 len
= table
->maxlen
;
2680 if(copy_from_user(table
->data
, newval
, len
))
2682 if (len
== table
->maxlen
)
2684 ((char *) table
->data
)[len
] = 0;
2690 * This function makes sure that all of the integers in the vector
2691 * are between the minimum and maximum values given in the arrays
2692 * table->extra1 and table->extra2, respectively.
2694 int sysctl_intvec(struct ctl_table
*table
, int __user
*name
, int nlen
,
2695 void __user
*oldval
, size_t __user
*oldlenp
,
2696 void __user
*newval
, size_t newlen
)
2699 if (newval
&& newlen
) {
2700 int __user
*vec
= (int __user
*) newval
;
2701 int *min
= (int *) table
->extra1
;
2702 int *max
= (int *) table
->extra2
;
2706 if (newlen
% sizeof(int) != 0)
2709 if (!table
->extra1
&& !table
->extra2
)
2712 if (newlen
> table
->maxlen
)
2713 newlen
= table
->maxlen
;
2714 length
= newlen
/ sizeof(int);
2716 for (i
= 0; i
< length
; i
++) {
2718 if (get_user(value
, vec
+ i
))
2720 if (min
&& value
< min
[i
])
2722 if (max
&& value
> max
[i
])
2729 /* Strategy function to convert jiffies to seconds */
2730 int sysctl_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2731 void __user
*oldval
, size_t __user
*oldlenp
,
2732 void __user
*newval
, size_t newlen
)
2734 if (oldval
&& oldlenp
) {
2737 if (get_user(olen
, oldlenp
))
2742 if (olen
< sizeof(int))
2745 val
= *(int *)(table
->data
) / HZ
;
2746 if (put_user(val
, (int __user
*)oldval
))
2748 if (put_user(sizeof(int), oldlenp
))
2752 if (newval
&& newlen
) {
2754 if (newlen
!= sizeof(int))
2756 if (get_user(new, (int __user
*)newval
))
2758 *(int *)(table
->data
) = new*HZ
;
2763 /* Strategy function to convert jiffies to seconds */
2764 int sysctl_ms_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2765 void __user
*oldval
, size_t __user
*oldlenp
,
2766 void __user
*newval
, size_t newlen
)
2768 if (oldval
&& oldlenp
) {
2771 if (get_user(olen
, oldlenp
))
2776 if (olen
< sizeof(int))
2779 val
= jiffies_to_msecs(*(int *)(table
->data
));
2780 if (put_user(val
, (int __user
*)oldval
))
2782 if (put_user(sizeof(int), oldlenp
))
2786 if (newval
&& newlen
) {
2788 if (newlen
!= sizeof(int))
2790 if (get_user(new, (int __user
*)newval
))
2792 *(int *)(table
->data
) = msecs_to_jiffies(new);
2799 #else /* CONFIG_SYSCTL_SYSCALL */
2802 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
2804 struct __sysctl_args tmp
;
2807 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
2810 error
= deprecated_sysctl_warning(&tmp
);
2812 /* If no error reading the parameters then just -ENOSYS ... */
2819 int sysctl_data(struct ctl_table
*table
, int __user
*name
, int nlen
,
2820 void __user
*oldval
, size_t __user
*oldlenp
,
2821 void __user
*newval
, size_t newlen
)
2826 int sysctl_string(struct ctl_table
*table
, int __user
*name
, int nlen
,
2827 void __user
*oldval
, size_t __user
*oldlenp
,
2828 void __user
*newval
, size_t newlen
)
2833 int sysctl_intvec(struct ctl_table
*table
, int __user
*name
, int nlen
,
2834 void __user
*oldval
, size_t __user
*oldlenp
,
2835 void __user
*newval
, size_t newlen
)
2840 int sysctl_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2841 void __user
*oldval
, size_t __user
*oldlenp
,
2842 void __user
*newval
, size_t newlen
)
2847 int sysctl_ms_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2848 void __user
*oldval
, size_t __user
*oldlenp
,
2849 void __user
*newval
, size_t newlen
)
2854 #endif /* CONFIG_SYSCTL_SYSCALL */
2856 static int deprecated_sysctl_warning(struct __sysctl_args
*args
)
2858 static int msg_count
;
2859 int name
[CTL_MAXNAME
];
2862 /* Check args->nlen. */
2863 if (args
->nlen
< 0 || args
->nlen
> CTL_MAXNAME
)
2866 /* Read in the sysctl name for better debug message logging */
2867 for (i
= 0; i
< args
->nlen
; i
++)
2868 if (get_user(name
[i
], args
->name
+ i
))
2871 /* Ignore accesses to kernel.version */
2872 if ((args
->nlen
== 2) && (name
[0] == CTL_KERN
) && (name
[1] == KERN_VERSION
))
2875 if (msg_count
< 5) {
2878 "warning: process `%s' used the deprecated sysctl "
2879 "system call with ", current
->comm
);
2880 for (i
= 0; i
< args
->nlen
; i
++)
2881 printk("%d.", name
[i
]);
2888 * No sense putting this after each symbol definition, twice,
2889 * exception granted :-)
2891 EXPORT_SYMBOL(proc_dointvec
);
2892 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2893 EXPORT_SYMBOL(proc_dointvec_minmax
);
2894 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2895 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2896 EXPORT_SYMBOL(proc_dostring
);
2897 EXPORT_SYMBOL(proc_doulongvec_minmax
);
2898 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
2899 EXPORT_SYMBOL(register_sysctl_table
);
2900 EXPORT_SYMBOL(register_sysctl_paths
);
2901 EXPORT_SYMBOL(sysctl_intvec
);
2902 EXPORT_SYMBOL(sysctl_jiffies
);
2903 EXPORT_SYMBOL(sysctl_ms_jiffies
);
2904 EXPORT_SYMBOL(sysctl_string
);
2905 EXPORT_SYMBOL(sysctl_data
);
2906 EXPORT_SYMBOL(unregister_sysctl_table
);