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/signal.h>
27 #include <linux/printk.h>
28 #include <linux/proc_fs.h>
29 #include <linux/security.h>
30 #include <linux/ctype.h>
31 #include <linux/kmemcheck.h>
33 #include <linux/init.h>
34 #include <linux/kernel.h>
35 #include <linux/kobject.h>
36 #include <linux/net.h>
37 #include <linux/sysrq.h>
38 #include <linux/highuid.h>
39 #include <linux/writeback.h>
40 #include <linux/ratelimit.h>
41 #include <linux/compaction.h>
42 #include <linux/hugetlb.h>
43 #include <linux/initrd.h>
44 #include <linux/key.h>
45 #include <linux/times.h>
46 #include <linux/limits.h>
47 #include <linux/dcache.h>
48 #include <linux/dnotify.h>
49 #include <linux/syscalls.h>
50 #include <linux/vmstat.h>
51 #include <linux/nfs_fs.h>
52 #include <linux/acpi.h>
53 #include <linux/reboot.h>
54 #include <linux/ftrace.h>
55 #include <linux/perf_event.h>
56 #include <linux/kprobes.h>
57 #include <linux/pipe_fs_i.h>
58 #include <linux/oom.h>
59 #include <linux/kmod.h>
60 #include <linux/capability.h>
61 #include <linux/binfmts.h>
63 #include <asm/uaccess.h>
64 #include <asm/processor.h>
68 #include <asm/stacktrace.h>
71 #ifdef CONFIG_BSD_PROCESS_ACCT
72 #include <linux/acct.h>
74 #ifdef CONFIG_RT_MUTEXES
75 #include <linux/rtmutex.h>
77 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
78 #include <linux/lockdep.h>
80 #ifdef CONFIG_CHR_DEV_SG
84 #ifdef CONFIG_LOCKUP_DETECTOR
85 #include <linux/nmi.h>
89 #if defined(CONFIG_SYSCTL)
91 /* External variables not in a header file. */
92 extern int sysctl_overcommit_memory
;
93 extern int sysctl_overcommit_ratio
;
94 extern int max_threads
;
95 extern int core_uses_pid
;
96 extern int suid_dumpable
;
97 extern char core_pattern
[];
98 extern unsigned int core_pipe_limit
;
100 extern int min_free_kbytes
;
101 extern int pid_max_min
, pid_max_max
;
102 extern int sysctl_drop_caches
;
103 extern int percpu_pagelist_fraction
;
104 extern int compat_log
;
105 extern int latencytop_enabled
;
106 extern int sysctl_nr_open_min
, sysctl_nr_open_max
;
108 extern int sysctl_nr_trim_pages
;
111 extern int blk_iopoll_enabled
;
114 /* Constants used for minimum and maximum */
115 #ifdef CONFIG_LOCKUP_DETECTOR
116 static int sixty
= 60;
117 static int neg_one
= -1;
121 static int __maybe_unused one
= 1;
122 static int __maybe_unused two
= 2;
123 static int __maybe_unused three
= 3;
124 static unsigned long one_ul
= 1;
125 static int one_hundred
= 100;
127 static int ten_thousand
= 10000;
130 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
131 static unsigned long dirty_bytes_min
= 2 * PAGE_SIZE
;
133 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
134 static int maxolduid
= 65535;
135 static int minolduid
;
136 static int min_percpu_pagelist_fract
= 8;
138 static int ngroups_max
= NGROUPS_MAX
;
139 static const int cap_last_cap
= CAP_LAST_CAP
;
141 #ifdef CONFIG_INOTIFY_USER
142 #include <linux/inotify.h>
145 #include <asm/system.h>
148 #ifdef CONFIG_SPARC64
149 extern int sysctl_tsb_ratio
;
153 extern int pwrsw_enabled
;
154 extern int unaligned_enabled
;
158 extern int no_unaligned_warning
;
159 extern int unaligned_dump_stack
;
162 #ifdef CONFIG_PROC_SYSCTL
163 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
164 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
165 static int proc_taint(struct ctl_table
*table
, int write
,
166 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
170 static int proc_dmesg_restrict(struct ctl_table
*table
, int write
,
171 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
174 #ifdef CONFIG_MAGIC_SYSRQ
175 /* Note: sysrq code uses it's own private copy */
176 static int __sysrq_enabled
= SYSRQ_DEFAULT_ENABLE
;
178 static int sysrq_sysctl_handler(ctl_table
*table
, int write
,
179 void __user
*buffer
, size_t *lenp
,
184 error
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
189 sysrq_toggle_support(__sysrq_enabled
);
196 static struct ctl_table root_table
[];
197 static struct ctl_table_root sysctl_table_root
;
198 static struct ctl_table_header root_table_header
= {
200 .ctl_table
= root_table
,
201 .ctl_entry
= LIST_HEAD_INIT(sysctl_table_root
.default_set
.list
),}},
202 .root
= &sysctl_table_root
,
203 .set
= &sysctl_table_root
.default_set
,
205 static struct ctl_table_root sysctl_table_root
= {
206 .root_list
= LIST_HEAD_INIT(sysctl_table_root
.root_list
),
207 .default_set
.list
= LIST_HEAD_INIT(root_table_header
.ctl_entry
),
210 static struct ctl_table kern_table
[];
211 static struct ctl_table vm_table
[];
212 static struct ctl_table fs_table
[];
213 static struct ctl_table debug_table
[];
214 static struct ctl_table dev_table
[];
215 extern struct ctl_table random_table
[];
217 extern struct ctl_table epoll_table
[];
220 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
221 int sysctl_legacy_va_layout
;
224 /* The default sysctl tables: */
226 static struct ctl_table root_table
[] = {
228 .procname
= "kernel",
245 .child
= debug_table
,
255 #ifdef CONFIG_SCHED_DEBUG
256 static int min_sched_granularity_ns
= 100000; /* 100 usecs */
257 static int max_sched_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
258 static int min_wakeup_granularity_ns
; /* 0 usecs */
259 static int max_wakeup_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
260 static int min_sched_tunable_scaling
= SCHED_TUNABLESCALING_NONE
;
261 static int max_sched_tunable_scaling
= SCHED_TUNABLESCALING_END
-1;
264 #ifdef CONFIG_COMPACTION
265 static int min_extfrag_threshold
;
266 static int max_extfrag_threshold
= 1000;
269 static struct ctl_table kern_table
[] = {
271 .procname
= "sched_child_runs_first",
272 .data
= &sysctl_sched_child_runs_first
,
273 .maxlen
= sizeof(unsigned int),
275 .proc_handler
= proc_dointvec
,
277 #ifdef CONFIG_SCHED_DEBUG
279 .procname
= "sched_min_granularity_ns",
280 .data
= &sysctl_sched_min_granularity
,
281 .maxlen
= sizeof(unsigned int),
283 .proc_handler
= sched_proc_update_handler
,
284 .extra1
= &min_sched_granularity_ns
,
285 .extra2
= &max_sched_granularity_ns
,
288 .procname
= "sched_latency_ns",
289 .data
= &sysctl_sched_latency
,
290 .maxlen
= sizeof(unsigned int),
292 .proc_handler
= sched_proc_update_handler
,
293 .extra1
= &min_sched_granularity_ns
,
294 .extra2
= &max_sched_granularity_ns
,
297 .procname
= "sched_wakeup_granularity_ns",
298 .data
= &sysctl_sched_wakeup_granularity
,
299 .maxlen
= sizeof(unsigned int),
301 .proc_handler
= sched_proc_update_handler
,
302 .extra1
= &min_wakeup_granularity_ns
,
303 .extra2
= &max_wakeup_granularity_ns
,
306 .procname
= "sched_tunable_scaling",
307 .data
= &sysctl_sched_tunable_scaling
,
308 .maxlen
= sizeof(enum sched_tunable_scaling
),
310 .proc_handler
= sched_proc_update_handler
,
311 .extra1
= &min_sched_tunable_scaling
,
312 .extra2
= &max_sched_tunable_scaling
,
315 .procname
= "sched_migration_cost",
316 .data
= &sysctl_sched_migration_cost
,
317 .maxlen
= sizeof(unsigned int),
319 .proc_handler
= proc_dointvec
,
322 .procname
= "sched_nr_migrate",
323 .data
= &sysctl_sched_nr_migrate
,
324 .maxlen
= sizeof(unsigned int),
326 .proc_handler
= proc_dointvec
,
329 .procname
= "sched_time_avg",
330 .data
= &sysctl_sched_time_avg
,
331 .maxlen
= sizeof(unsigned int),
333 .proc_handler
= proc_dointvec
,
336 .procname
= "sched_shares_window",
337 .data
= &sysctl_sched_shares_window
,
338 .maxlen
= sizeof(unsigned int),
340 .proc_handler
= proc_dointvec
,
343 .procname
= "timer_migration",
344 .data
= &sysctl_timer_migration
,
345 .maxlen
= sizeof(unsigned int),
347 .proc_handler
= proc_dointvec_minmax
,
353 .procname
= "sched_rt_period_us",
354 .data
= &sysctl_sched_rt_period
,
355 .maxlen
= sizeof(unsigned int),
357 .proc_handler
= sched_rt_handler
,
360 .procname
= "sched_rt_runtime_us",
361 .data
= &sysctl_sched_rt_runtime
,
362 .maxlen
= sizeof(int),
364 .proc_handler
= sched_rt_handler
,
366 #ifdef CONFIG_SCHED_AUTOGROUP
368 .procname
= "sched_autogroup_enabled",
369 .data
= &sysctl_sched_autogroup_enabled
,
370 .maxlen
= sizeof(unsigned int),
372 .proc_handler
= proc_dointvec_minmax
,
377 #ifdef CONFIG_CFS_BANDWIDTH
379 .procname
= "sched_cfs_bandwidth_slice_us",
380 .data
= &sysctl_sched_cfs_bandwidth_slice
,
381 .maxlen
= sizeof(unsigned int),
383 .proc_handler
= proc_dointvec_minmax
,
387 #ifdef CONFIG_PROVE_LOCKING
389 .procname
= "prove_locking",
390 .data
= &prove_locking
,
391 .maxlen
= sizeof(int),
393 .proc_handler
= proc_dointvec
,
396 #ifdef CONFIG_LOCK_STAT
398 .procname
= "lock_stat",
400 .maxlen
= sizeof(int),
402 .proc_handler
= proc_dointvec
,
407 .data
= &panic_timeout
,
408 .maxlen
= sizeof(int),
410 .proc_handler
= proc_dointvec
,
413 .procname
= "core_uses_pid",
414 .data
= &core_uses_pid
,
415 .maxlen
= sizeof(int),
417 .proc_handler
= proc_dointvec
,
420 .procname
= "core_pattern",
421 .data
= core_pattern
,
422 .maxlen
= CORENAME_MAX_SIZE
,
424 .proc_handler
= proc_dostring
,
427 .procname
= "core_pipe_limit",
428 .data
= &core_pipe_limit
,
429 .maxlen
= sizeof(unsigned int),
431 .proc_handler
= proc_dointvec
,
433 #ifdef CONFIG_PROC_SYSCTL
435 .procname
= "tainted",
436 .maxlen
= sizeof(long),
438 .proc_handler
= proc_taint
,
441 #ifdef CONFIG_LATENCYTOP
443 .procname
= "latencytop",
444 .data
= &latencytop_enabled
,
445 .maxlen
= sizeof(int),
447 .proc_handler
= proc_dointvec
,
450 #ifdef CONFIG_BLK_DEV_INITRD
452 .procname
= "real-root-dev",
453 .data
= &real_root_dev
,
454 .maxlen
= sizeof(int),
456 .proc_handler
= proc_dointvec
,
460 .procname
= "print-fatal-signals",
461 .data
= &print_fatal_signals
,
462 .maxlen
= sizeof(int),
464 .proc_handler
= proc_dointvec
,
468 .procname
= "reboot-cmd",
469 .data
= reboot_command
,
472 .proc_handler
= proc_dostring
,
475 .procname
= "stop-a",
476 .data
= &stop_a_enabled
,
477 .maxlen
= sizeof (int),
479 .proc_handler
= proc_dointvec
,
482 .procname
= "scons-poweroff",
483 .data
= &scons_pwroff
,
484 .maxlen
= sizeof (int),
486 .proc_handler
= proc_dointvec
,
489 #ifdef CONFIG_SPARC64
491 .procname
= "tsb-ratio",
492 .data
= &sysctl_tsb_ratio
,
493 .maxlen
= sizeof (int),
495 .proc_handler
= proc_dointvec
,
500 .procname
= "soft-power",
501 .data
= &pwrsw_enabled
,
502 .maxlen
= sizeof (int),
504 .proc_handler
= proc_dointvec
,
507 .procname
= "unaligned-trap",
508 .data
= &unaligned_enabled
,
509 .maxlen
= sizeof (int),
511 .proc_handler
= proc_dointvec
,
515 .procname
= "ctrl-alt-del",
517 .maxlen
= sizeof(int),
519 .proc_handler
= proc_dointvec
,
521 #ifdef CONFIG_FUNCTION_TRACER
523 .procname
= "ftrace_enabled",
524 .data
= &ftrace_enabled
,
525 .maxlen
= sizeof(int),
527 .proc_handler
= ftrace_enable_sysctl
,
530 #ifdef CONFIG_STACK_TRACER
532 .procname
= "stack_tracer_enabled",
533 .data
= &stack_tracer_enabled
,
534 .maxlen
= sizeof(int),
536 .proc_handler
= stack_trace_sysctl
,
539 #ifdef CONFIG_TRACING
541 .procname
= "ftrace_dump_on_oops",
542 .data
= &ftrace_dump_on_oops
,
543 .maxlen
= sizeof(int),
545 .proc_handler
= proc_dointvec
,
548 #ifdef CONFIG_MODULES
550 .procname
= "modprobe",
551 .data
= &modprobe_path
,
552 .maxlen
= KMOD_PATH_LEN
,
554 .proc_handler
= proc_dostring
,
557 .procname
= "modules_disabled",
558 .data
= &modules_disabled
,
559 .maxlen
= sizeof(int),
561 /* only handle a transition from default "0" to "1" */
562 .proc_handler
= proc_dointvec_minmax
,
567 #ifdef CONFIG_HOTPLUG
569 .procname
= "hotplug",
570 .data
= &uevent_helper
,
571 .maxlen
= UEVENT_HELPER_PATH_LEN
,
573 .proc_handler
= proc_dostring
,
576 #ifdef CONFIG_CHR_DEV_SG
578 .procname
= "sg-big-buff",
579 .data
= &sg_big_buff
,
580 .maxlen
= sizeof (int),
582 .proc_handler
= proc_dointvec
,
585 #ifdef CONFIG_BSD_PROCESS_ACCT
589 .maxlen
= 3*sizeof(int),
591 .proc_handler
= proc_dointvec
,
594 #ifdef CONFIG_MAGIC_SYSRQ
597 .data
= &__sysrq_enabled
,
598 .maxlen
= sizeof (int),
600 .proc_handler
= sysrq_sysctl_handler
,
603 #ifdef CONFIG_PROC_SYSCTL
605 .procname
= "cad_pid",
607 .maxlen
= sizeof (int),
609 .proc_handler
= proc_do_cad_pid
,
613 .procname
= "threads-max",
614 .data
= &max_threads
,
615 .maxlen
= sizeof(int),
617 .proc_handler
= proc_dointvec
,
620 .procname
= "random",
622 .child
= random_table
,
625 .procname
= "usermodehelper",
627 .child
= usermodehelper_table
,
630 .procname
= "overflowuid",
631 .data
= &overflowuid
,
632 .maxlen
= sizeof(int),
634 .proc_handler
= proc_dointvec_minmax
,
635 .extra1
= &minolduid
,
636 .extra2
= &maxolduid
,
639 .procname
= "overflowgid",
640 .data
= &overflowgid
,
641 .maxlen
= sizeof(int),
643 .proc_handler
= proc_dointvec_minmax
,
644 .extra1
= &minolduid
,
645 .extra2
= &maxolduid
,
648 #ifdef CONFIG_MATHEMU
650 .procname
= "ieee_emulation_warnings",
651 .data
= &sysctl_ieee_emulation_warnings
,
652 .maxlen
= sizeof(int),
654 .proc_handler
= proc_dointvec
,
658 .procname
= "userprocess_debug",
659 .data
= &show_unhandled_signals
,
660 .maxlen
= sizeof(int),
662 .proc_handler
= proc_dointvec
,
666 .procname
= "pid_max",
668 .maxlen
= sizeof (int),
670 .proc_handler
= proc_dointvec_minmax
,
671 .extra1
= &pid_max_min
,
672 .extra2
= &pid_max_max
,
675 .procname
= "panic_on_oops",
676 .data
= &panic_on_oops
,
677 .maxlen
= sizeof(int),
679 .proc_handler
= proc_dointvec
,
681 #if defined CONFIG_PRINTK
683 .procname
= "printk",
684 .data
= &console_loglevel
,
685 .maxlen
= 4*sizeof(int),
687 .proc_handler
= proc_dointvec
,
690 .procname
= "printk_ratelimit",
691 .data
= &printk_ratelimit_state
.interval
,
692 .maxlen
= sizeof(int),
694 .proc_handler
= proc_dointvec_jiffies
,
697 .procname
= "printk_ratelimit_burst",
698 .data
= &printk_ratelimit_state
.burst
,
699 .maxlen
= sizeof(int),
701 .proc_handler
= proc_dointvec
,
704 .procname
= "printk_delay",
705 .data
= &printk_delay_msec
,
706 .maxlen
= sizeof(int),
708 .proc_handler
= proc_dointvec_minmax
,
710 .extra2
= &ten_thousand
,
713 .procname
= "dmesg_restrict",
714 .data
= &dmesg_restrict
,
715 .maxlen
= sizeof(int),
717 .proc_handler
= proc_dointvec_minmax
,
722 .procname
= "kptr_restrict",
723 .data
= &kptr_restrict
,
724 .maxlen
= sizeof(int),
726 .proc_handler
= proc_dmesg_restrict
,
732 .procname
= "ngroups_max",
733 .data
= &ngroups_max
,
734 .maxlen
= sizeof (int),
736 .proc_handler
= proc_dointvec
,
739 .procname
= "cap_last_cap",
740 .data
= (void *)&cap_last_cap
,
741 .maxlen
= sizeof(int),
743 .proc_handler
= proc_dointvec
,
745 #if defined(CONFIG_LOCKUP_DETECTOR)
747 .procname
= "watchdog",
748 .data
= &watchdog_enabled
,
749 .maxlen
= sizeof (int),
751 .proc_handler
= proc_dowatchdog
,
756 .procname
= "watchdog_thresh",
757 .data
= &watchdog_thresh
,
758 .maxlen
= sizeof(int),
760 .proc_handler
= proc_dowatchdog
,
765 .procname
= "softlockup_panic",
766 .data
= &softlockup_panic
,
767 .maxlen
= sizeof(int),
769 .proc_handler
= proc_dointvec_minmax
,
774 .procname
= "nmi_watchdog",
775 .data
= &watchdog_enabled
,
776 .maxlen
= sizeof (int),
778 .proc_handler
= proc_dowatchdog
,
783 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
785 .procname
= "unknown_nmi_panic",
786 .data
= &unknown_nmi_panic
,
787 .maxlen
= sizeof (int),
789 .proc_handler
= proc_dointvec
,
792 #if defined(CONFIG_X86)
794 .procname
= "panic_on_unrecovered_nmi",
795 .data
= &panic_on_unrecovered_nmi
,
796 .maxlen
= sizeof(int),
798 .proc_handler
= proc_dointvec
,
801 .procname
= "panic_on_io_nmi",
802 .data
= &panic_on_io_nmi
,
803 .maxlen
= sizeof(int),
805 .proc_handler
= proc_dointvec
,
807 #ifdef CONFIG_DEBUG_STACKOVERFLOW
809 .procname
= "panic_on_stackoverflow",
810 .data
= &sysctl_panic_on_stackoverflow
,
811 .maxlen
= sizeof(int),
813 .proc_handler
= proc_dointvec
,
817 .procname
= "bootloader_type",
818 .data
= &bootloader_type
,
819 .maxlen
= sizeof (int),
821 .proc_handler
= proc_dointvec
,
824 .procname
= "bootloader_version",
825 .data
= &bootloader_version
,
826 .maxlen
= sizeof (int),
828 .proc_handler
= proc_dointvec
,
831 .procname
= "kstack_depth_to_print",
832 .data
= &kstack_depth_to_print
,
833 .maxlen
= sizeof(int),
835 .proc_handler
= proc_dointvec
,
838 .procname
= "io_delay_type",
839 .data
= &io_delay_type
,
840 .maxlen
= sizeof(int),
842 .proc_handler
= proc_dointvec
,
845 #if defined(CONFIG_MMU)
847 .procname
= "randomize_va_space",
848 .data
= &randomize_va_space
,
849 .maxlen
= sizeof(int),
851 .proc_handler
= proc_dointvec
,
854 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
856 .procname
= "spin_retry",
858 .maxlen
= sizeof (int),
860 .proc_handler
= proc_dointvec
,
863 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
865 .procname
= "acpi_video_flags",
866 .data
= &acpi_realmode_flags
,
867 .maxlen
= sizeof (unsigned long),
869 .proc_handler
= proc_doulongvec_minmax
,
874 .procname
= "ignore-unaligned-usertrap",
875 .data
= &no_unaligned_warning
,
876 .maxlen
= sizeof (int),
878 .proc_handler
= proc_dointvec
,
881 .procname
= "unaligned-dump-stack",
882 .data
= &unaligned_dump_stack
,
883 .maxlen
= sizeof (int),
885 .proc_handler
= proc_dointvec
,
888 #ifdef CONFIG_DETECT_HUNG_TASK
890 .procname
= "hung_task_panic",
891 .data
= &sysctl_hung_task_panic
,
892 .maxlen
= sizeof(int),
894 .proc_handler
= proc_dointvec_minmax
,
899 .procname
= "hung_task_check_count",
900 .data
= &sysctl_hung_task_check_count
,
901 .maxlen
= sizeof(unsigned long),
903 .proc_handler
= proc_doulongvec_minmax
,
906 .procname
= "hung_task_timeout_secs",
907 .data
= &sysctl_hung_task_timeout_secs
,
908 .maxlen
= sizeof(unsigned long),
910 .proc_handler
= proc_dohung_task_timeout_secs
,
913 .procname
= "hung_task_warnings",
914 .data
= &sysctl_hung_task_warnings
,
915 .maxlen
= sizeof(unsigned long),
917 .proc_handler
= proc_doulongvec_minmax
,
922 .procname
= "compat-log",
924 .maxlen
= sizeof (int),
926 .proc_handler
= proc_dointvec
,
929 #ifdef CONFIG_RT_MUTEXES
931 .procname
= "max_lock_depth",
932 .data
= &max_lock_depth
,
933 .maxlen
= sizeof(int),
935 .proc_handler
= proc_dointvec
,
939 .procname
= "poweroff_cmd",
940 .data
= &poweroff_cmd
,
941 .maxlen
= POWEROFF_CMD_PATH_LEN
,
943 .proc_handler
= proc_dostring
,
949 .child
= key_sysctls
,
952 #ifdef CONFIG_RCU_TORTURE_TEST
954 .procname
= "rcutorture_runnable",
955 .data
= &rcutorture_runnable
,
956 .maxlen
= sizeof(int),
958 .proc_handler
= proc_dointvec
,
961 #ifdef CONFIG_PERF_EVENTS
963 * User-space scripts rely on the existence of this file
964 * as a feature check for perf_events being enabled.
966 * So it's an ABI, do not remove!
969 .procname
= "perf_event_paranoid",
970 .data
= &sysctl_perf_event_paranoid
,
971 .maxlen
= sizeof(sysctl_perf_event_paranoid
),
973 .proc_handler
= proc_dointvec
,
976 .procname
= "perf_event_mlock_kb",
977 .data
= &sysctl_perf_event_mlock
,
978 .maxlen
= sizeof(sysctl_perf_event_mlock
),
980 .proc_handler
= proc_dointvec
,
983 .procname
= "perf_event_max_sample_rate",
984 .data
= &sysctl_perf_event_sample_rate
,
985 .maxlen
= sizeof(sysctl_perf_event_sample_rate
),
987 .proc_handler
= perf_proc_update_handler
,
990 #ifdef CONFIG_KMEMCHECK
992 .procname
= "kmemcheck",
993 .data
= &kmemcheck_enabled
,
994 .maxlen
= sizeof(int),
996 .proc_handler
= proc_dointvec
,
1001 .procname
= "blk_iopoll",
1002 .data
= &blk_iopoll_enabled
,
1003 .maxlen
= sizeof(int),
1005 .proc_handler
= proc_dointvec
,
1011 static struct ctl_table vm_table
[] = {
1013 .procname
= "overcommit_memory",
1014 .data
= &sysctl_overcommit_memory
,
1015 .maxlen
= sizeof(sysctl_overcommit_memory
),
1017 .proc_handler
= proc_dointvec_minmax
,
1022 .procname
= "panic_on_oom",
1023 .data
= &sysctl_panic_on_oom
,
1024 .maxlen
= sizeof(sysctl_panic_on_oom
),
1026 .proc_handler
= proc_dointvec_minmax
,
1031 .procname
= "oom_kill_allocating_task",
1032 .data
= &sysctl_oom_kill_allocating_task
,
1033 .maxlen
= sizeof(sysctl_oom_kill_allocating_task
),
1035 .proc_handler
= proc_dointvec
,
1038 .procname
= "oom_dump_tasks",
1039 .data
= &sysctl_oom_dump_tasks
,
1040 .maxlen
= sizeof(sysctl_oom_dump_tasks
),
1042 .proc_handler
= proc_dointvec
,
1045 .procname
= "overcommit_ratio",
1046 .data
= &sysctl_overcommit_ratio
,
1047 .maxlen
= sizeof(sysctl_overcommit_ratio
),
1049 .proc_handler
= proc_dointvec
,
1052 .procname
= "page-cluster",
1053 .data
= &page_cluster
,
1054 .maxlen
= sizeof(int),
1056 .proc_handler
= proc_dointvec_minmax
,
1060 .procname
= "dirty_background_ratio",
1061 .data
= &dirty_background_ratio
,
1062 .maxlen
= sizeof(dirty_background_ratio
),
1064 .proc_handler
= dirty_background_ratio_handler
,
1066 .extra2
= &one_hundred
,
1069 .procname
= "dirty_background_bytes",
1070 .data
= &dirty_background_bytes
,
1071 .maxlen
= sizeof(dirty_background_bytes
),
1073 .proc_handler
= dirty_background_bytes_handler
,
1077 .procname
= "dirty_ratio",
1078 .data
= &vm_dirty_ratio
,
1079 .maxlen
= sizeof(vm_dirty_ratio
),
1081 .proc_handler
= dirty_ratio_handler
,
1083 .extra2
= &one_hundred
,
1086 .procname
= "dirty_bytes",
1087 .data
= &vm_dirty_bytes
,
1088 .maxlen
= sizeof(vm_dirty_bytes
),
1090 .proc_handler
= dirty_bytes_handler
,
1091 .extra1
= &dirty_bytes_min
,
1094 .procname
= "dirty_writeback_centisecs",
1095 .data
= &dirty_writeback_interval
,
1096 .maxlen
= sizeof(dirty_writeback_interval
),
1098 .proc_handler
= dirty_writeback_centisecs_handler
,
1101 .procname
= "dirty_expire_centisecs",
1102 .data
= &dirty_expire_interval
,
1103 .maxlen
= sizeof(dirty_expire_interval
),
1105 .proc_handler
= proc_dointvec_minmax
,
1109 .procname
= "nr_pdflush_threads",
1110 .data
= &nr_pdflush_threads
,
1111 .maxlen
= sizeof nr_pdflush_threads
,
1112 .mode
= 0444 /* read-only*/,
1113 .proc_handler
= proc_dointvec
,
1116 .procname
= "swappiness",
1117 .data
= &vm_swappiness
,
1118 .maxlen
= sizeof(vm_swappiness
),
1120 .proc_handler
= proc_dointvec_minmax
,
1122 .extra2
= &one_hundred
,
1124 #ifdef CONFIG_HUGETLB_PAGE
1126 .procname
= "nr_hugepages",
1128 .maxlen
= sizeof(unsigned long),
1130 .proc_handler
= hugetlb_sysctl_handler
,
1131 .extra1
= (void *)&hugetlb_zero
,
1132 .extra2
= (void *)&hugetlb_infinity
,
1136 .procname
= "nr_hugepages_mempolicy",
1138 .maxlen
= sizeof(unsigned long),
1140 .proc_handler
= &hugetlb_mempolicy_sysctl_handler
,
1141 .extra1
= (void *)&hugetlb_zero
,
1142 .extra2
= (void *)&hugetlb_infinity
,
1146 .procname
= "hugetlb_shm_group",
1147 .data
= &sysctl_hugetlb_shm_group
,
1148 .maxlen
= sizeof(gid_t
),
1150 .proc_handler
= proc_dointvec
,
1153 .procname
= "hugepages_treat_as_movable",
1154 .data
= &hugepages_treat_as_movable
,
1155 .maxlen
= sizeof(int),
1157 .proc_handler
= hugetlb_treat_movable_handler
,
1160 .procname
= "nr_overcommit_hugepages",
1162 .maxlen
= sizeof(unsigned long),
1164 .proc_handler
= hugetlb_overcommit_handler
,
1165 .extra1
= (void *)&hugetlb_zero
,
1166 .extra2
= (void *)&hugetlb_infinity
,
1170 .procname
= "lowmem_reserve_ratio",
1171 .data
= &sysctl_lowmem_reserve_ratio
,
1172 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
1174 .proc_handler
= lowmem_reserve_ratio_sysctl_handler
,
1177 .procname
= "drop_caches",
1178 .data
= &sysctl_drop_caches
,
1179 .maxlen
= sizeof(int),
1181 .proc_handler
= drop_caches_sysctl_handler
,
1185 #ifdef CONFIG_COMPACTION
1187 .procname
= "compact_memory",
1188 .data
= &sysctl_compact_memory
,
1189 .maxlen
= sizeof(int),
1191 .proc_handler
= sysctl_compaction_handler
,
1194 .procname
= "extfrag_threshold",
1195 .data
= &sysctl_extfrag_threshold
,
1196 .maxlen
= sizeof(int),
1198 .proc_handler
= sysctl_extfrag_handler
,
1199 .extra1
= &min_extfrag_threshold
,
1200 .extra2
= &max_extfrag_threshold
,
1203 #endif /* CONFIG_COMPACTION */
1205 .procname
= "min_free_kbytes",
1206 .data
= &min_free_kbytes
,
1207 .maxlen
= sizeof(min_free_kbytes
),
1209 .proc_handler
= min_free_kbytes_sysctl_handler
,
1213 .procname
= "percpu_pagelist_fraction",
1214 .data
= &percpu_pagelist_fraction
,
1215 .maxlen
= sizeof(percpu_pagelist_fraction
),
1217 .proc_handler
= percpu_pagelist_fraction_sysctl_handler
,
1218 .extra1
= &min_percpu_pagelist_fract
,
1222 .procname
= "max_map_count",
1223 .data
= &sysctl_max_map_count
,
1224 .maxlen
= sizeof(sysctl_max_map_count
),
1226 .proc_handler
= proc_dointvec_minmax
,
1231 .procname
= "nr_trim_pages",
1232 .data
= &sysctl_nr_trim_pages
,
1233 .maxlen
= sizeof(sysctl_nr_trim_pages
),
1235 .proc_handler
= proc_dointvec_minmax
,
1240 .procname
= "laptop_mode",
1241 .data
= &laptop_mode
,
1242 .maxlen
= sizeof(laptop_mode
),
1244 .proc_handler
= proc_dointvec_jiffies
,
1247 .procname
= "block_dump",
1248 .data
= &block_dump
,
1249 .maxlen
= sizeof(block_dump
),
1251 .proc_handler
= proc_dointvec
,
1255 .procname
= "vfs_cache_pressure",
1256 .data
= &sysctl_vfs_cache_pressure
,
1257 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
1259 .proc_handler
= proc_dointvec
,
1262 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1264 .procname
= "legacy_va_layout",
1265 .data
= &sysctl_legacy_va_layout
,
1266 .maxlen
= sizeof(sysctl_legacy_va_layout
),
1268 .proc_handler
= proc_dointvec
,
1274 .procname
= "zone_reclaim_mode",
1275 .data
= &zone_reclaim_mode
,
1276 .maxlen
= sizeof(zone_reclaim_mode
),
1278 .proc_handler
= proc_dointvec
,
1282 .procname
= "min_unmapped_ratio",
1283 .data
= &sysctl_min_unmapped_ratio
,
1284 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1286 .proc_handler
= sysctl_min_unmapped_ratio_sysctl_handler
,
1288 .extra2
= &one_hundred
,
1291 .procname
= "min_slab_ratio",
1292 .data
= &sysctl_min_slab_ratio
,
1293 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1295 .proc_handler
= sysctl_min_slab_ratio_sysctl_handler
,
1297 .extra2
= &one_hundred
,
1302 .procname
= "stat_interval",
1303 .data
= &sysctl_stat_interval
,
1304 .maxlen
= sizeof(sysctl_stat_interval
),
1306 .proc_handler
= proc_dointvec_jiffies
,
1311 .procname
= "mmap_min_addr",
1312 .data
= &dac_mmap_min_addr
,
1313 .maxlen
= sizeof(unsigned long),
1315 .proc_handler
= mmap_min_addr_handler
,
1320 .procname
= "numa_zonelist_order",
1321 .data
= &numa_zonelist_order
,
1322 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1324 .proc_handler
= numa_zonelist_order_handler
,
1327 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1328 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1330 .procname
= "vdso_enabled",
1331 .data
= &vdso_enabled
,
1332 .maxlen
= sizeof(vdso_enabled
),
1334 .proc_handler
= proc_dointvec
,
1338 #ifdef CONFIG_HIGHMEM
1340 .procname
= "highmem_is_dirtyable",
1341 .data
= &vm_highmem_is_dirtyable
,
1342 .maxlen
= sizeof(vm_highmem_is_dirtyable
),
1344 .proc_handler
= proc_dointvec_minmax
,
1350 .procname
= "scan_unevictable_pages",
1351 .data
= &scan_unevictable_pages
,
1352 .maxlen
= sizeof(scan_unevictable_pages
),
1354 .proc_handler
= scan_unevictable_handler
,
1356 #ifdef CONFIG_MEMORY_FAILURE
1358 .procname
= "memory_failure_early_kill",
1359 .data
= &sysctl_memory_failure_early_kill
,
1360 .maxlen
= sizeof(sysctl_memory_failure_early_kill
),
1362 .proc_handler
= proc_dointvec_minmax
,
1367 .procname
= "memory_failure_recovery",
1368 .data
= &sysctl_memory_failure_recovery
,
1369 .maxlen
= sizeof(sysctl_memory_failure_recovery
),
1371 .proc_handler
= proc_dointvec_minmax
,
1379 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1380 static struct ctl_table binfmt_misc_table
[] = {
1385 static struct ctl_table fs_table
[] = {
1387 .procname
= "inode-nr",
1388 .data
= &inodes_stat
,
1389 .maxlen
= 2*sizeof(int),
1391 .proc_handler
= proc_nr_inodes
,
1394 .procname
= "inode-state",
1395 .data
= &inodes_stat
,
1396 .maxlen
= 7*sizeof(int),
1398 .proc_handler
= proc_nr_inodes
,
1401 .procname
= "file-nr",
1402 .data
= &files_stat
,
1403 .maxlen
= sizeof(files_stat
),
1405 .proc_handler
= proc_nr_files
,
1408 .procname
= "file-max",
1409 .data
= &files_stat
.max_files
,
1410 .maxlen
= sizeof(files_stat
.max_files
),
1412 .proc_handler
= proc_doulongvec_minmax
,
1415 .procname
= "nr_open",
1416 .data
= &sysctl_nr_open
,
1417 .maxlen
= sizeof(int),
1419 .proc_handler
= proc_dointvec_minmax
,
1420 .extra1
= &sysctl_nr_open_min
,
1421 .extra2
= &sysctl_nr_open_max
,
1424 .procname
= "dentry-state",
1425 .data
= &dentry_stat
,
1426 .maxlen
= 6*sizeof(int),
1428 .proc_handler
= proc_nr_dentry
,
1431 .procname
= "overflowuid",
1432 .data
= &fs_overflowuid
,
1433 .maxlen
= sizeof(int),
1435 .proc_handler
= proc_dointvec_minmax
,
1436 .extra1
= &minolduid
,
1437 .extra2
= &maxolduid
,
1440 .procname
= "overflowgid",
1441 .data
= &fs_overflowgid
,
1442 .maxlen
= sizeof(int),
1444 .proc_handler
= proc_dointvec_minmax
,
1445 .extra1
= &minolduid
,
1446 .extra2
= &maxolduid
,
1448 #ifdef CONFIG_FILE_LOCKING
1450 .procname
= "leases-enable",
1451 .data
= &leases_enable
,
1452 .maxlen
= sizeof(int),
1454 .proc_handler
= proc_dointvec
,
1457 #ifdef CONFIG_DNOTIFY
1459 .procname
= "dir-notify-enable",
1460 .data
= &dir_notify_enable
,
1461 .maxlen
= sizeof(int),
1463 .proc_handler
= proc_dointvec
,
1467 #ifdef CONFIG_FILE_LOCKING
1469 .procname
= "lease-break-time",
1470 .data
= &lease_break_time
,
1471 .maxlen
= sizeof(int),
1473 .proc_handler
= proc_dointvec
,
1478 .procname
= "aio-nr",
1480 .maxlen
= sizeof(aio_nr
),
1482 .proc_handler
= proc_doulongvec_minmax
,
1485 .procname
= "aio-max-nr",
1486 .data
= &aio_max_nr
,
1487 .maxlen
= sizeof(aio_max_nr
),
1489 .proc_handler
= proc_doulongvec_minmax
,
1491 #endif /* CONFIG_AIO */
1492 #ifdef CONFIG_INOTIFY_USER
1494 .procname
= "inotify",
1496 .child
= inotify_table
,
1501 .procname
= "epoll",
1503 .child
= epoll_table
,
1508 .procname
= "suid_dumpable",
1509 .data
= &suid_dumpable
,
1510 .maxlen
= sizeof(int),
1512 .proc_handler
= proc_dointvec_minmax
,
1516 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1518 .procname
= "binfmt_misc",
1520 .child
= binfmt_misc_table
,
1524 .procname
= "pipe-max-size",
1525 .data
= &pipe_max_size
,
1526 .maxlen
= sizeof(int),
1528 .proc_handler
= &pipe_proc_fn
,
1529 .extra1
= &pipe_min_size
,
1534 static struct ctl_table debug_table
[] = {
1535 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1536 defined(CONFIG_S390) || defined(CONFIG_TILE)
1538 .procname
= "exception-trace",
1539 .data
= &show_unhandled_signals
,
1540 .maxlen
= sizeof(int),
1542 .proc_handler
= proc_dointvec
1545 #if defined(CONFIG_OPTPROBES)
1547 .procname
= "kprobes-optimization",
1548 .data
= &sysctl_kprobes_optimization
,
1549 .maxlen
= sizeof(int),
1551 .proc_handler
= proc_kprobes_optimization_handler
,
1559 static struct ctl_table dev_table
[] = {
1563 static DEFINE_SPINLOCK(sysctl_lock
);
1565 /* called under sysctl_lock */
1566 static int use_table(struct ctl_table_header
*p
)
1568 if (unlikely(p
->unregistering
))
1574 /* called under sysctl_lock */
1575 static void unuse_table(struct ctl_table_header
*p
)
1578 if (unlikely(p
->unregistering
))
1579 complete(p
->unregistering
);
1582 /* called under sysctl_lock, will reacquire if has to wait */
1583 static void start_unregistering(struct ctl_table_header
*p
)
1586 * if p->used is 0, nobody will ever touch that entry again;
1587 * we'll eliminate all paths to it before dropping sysctl_lock
1589 if (unlikely(p
->used
)) {
1590 struct completion wait
;
1591 init_completion(&wait
);
1592 p
->unregistering
= &wait
;
1593 spin_unlock(&sysctl_lock
);
1594 wait_for_completion(&wait
);
1595 spin_lock(&sysctl_lock
);
1597 /* anything non-NULL; we'll never dereference it */
1598 p
->unregistering
= ERR_PTR(-EINVAL
);
1601 * do not remove from the list until nobody holds it; walking the
1602 * list in do_sysctl() relies on that.
1604 list_del_init(&p
->ctl_entry
);
1607 void sysctl_head_get(struct ctl_table_header
*head
)
1609 spin_lock(&sysctl_lock
);
1611 spin_unlock(&sysctl_lock
);
1614 void sysctl_head_put(struct ctl_table_header
*head
)
1616 spin_lock(&sysctl_lock
);
1618 kfree_rcu(head
, rcu
);
1619 spin_unlock(&sysctl_lock
);
1622 struct ctl_table_header
*sysctl_head_grab(struct ctl_table_header
*head
)
1626 spin_lock(&sysctl_lock
);
1627 if (!use_table(head
))
1628 head
= ERR_PTR(-ENOENT
);
1629 spin_unlock(&sysctl_lock
);
1633 void sysctl_head_finish(struct ctl_table_header
*head
)
1637 spin_lock(&sysctl_lock
);
1639 spin_unlock(&sysctl_lock
);
1642 static struct ctl_table_set
*
1643 lookup_header_set(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1645 struct ctl_table_set
*set
= &root
->default_set
;
1647 set
= root
->lookup(root
, namespaces
);
1651 static struct list_head
*
1652 lookup_header_list(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1654 struct ctl_table_set
*set
= lookup_header_set(root
, namespaces
);
1658 struct ctl_table_header
*__sysctl_head_next(struct nsproxy
*namespaces
,
1659 struct ctl_table_header
*prev
)
1661 struct ctl_table_root
*root
;
1662 struct list_head
*header_list
;
1663 struct ctl_table_header
*head
;
1664 struct list_head
*tmp
;
1666 spin_lock(&sysctl_lock
);
1669 tmp
= &prev
->ctl_entry
;
1673 tmp
= &root_table_header
.ctl_entry
;
1675 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1677 if (!use_table(head
))
1679 spin_unlock(&sysctl_lock
);
1684 header_list
= lookup_header_list(root
, namespaces
);
1685 if (tmp
!= header_list
)
1689 root
= list_entry(root
->root_list
.next
,
1690 struct ctl_table_root
, root_list
);
1691 if (root
== &sysctl_table_root
)
1693 header_list
= lookup_header_list(root
, namespaces
);
1694 } while (list_empty(header_list
));
1695 tmp
= header_list
->next
;
1698 spin_unlock(&sysctl_lock
);
1702 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1704 return __sysctl_head_next(current
->nsproxy
, prev
);
1707 void register_sysctl_root(struct ctl_table_root
*root
)
1709 spin_lock(&sysctl_lock
);
1710 list_add_tail(&root
->root_list
, &sysctl_table_root
.root_list
);
1711 spin_unlock(&sysctl_lock
);
1715 * sysctl_perm does NOT grant the superuser all rights automatically, because
1716 * some sysctl variables are readonly even to root.
1719 static int test_perm(int mode
, int op
)
1721 if (!current_euid())
1723 else if (in_egroup_p(0))
1725 if ((op
& ~mode
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
)) == 0)
1730 int sysctl_perm(struct ctl_table_root
*root
, struct ctl_table
*table
, int op
)
1734 if (root
->permissions
)
1735 mode
= root
->permissions(root
, current
->nsproxy
, table
);
1739 return test_perm(mode
, op
);
1742 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1744 for (; table
->procname
; table
++) {
1745 table
->parent
= parent
;
1747 sysctl_set_parent(table
, table
->child
);
1751 static __init
int sysctl_init(void)
1753 sysctl_set_parent(NULL
, root_table
);
1754 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1755 sysctl_check_table(current
->nsproxy
, root_table
);
1760 core_initcall(sysctl_init
);
1762 static struct ctl_table
*is_branch_in(struct ctl_table
*branch
,
1763 struct ctl_table
*table
)
1765 struct ctl_table
*p
;
1766 const char *s
= branch
->procname
;
1768 /* branch should have named subdirectory as its first element */
1769 if (!s
|| !branch
->child
)
1772 /* ... and nothing else */
1773 if (branch
[1].procname
)
1776 /* table should contain subdirectory with the same name */
1777 for (p
= table
; p
->procname
; p
++) {
1780 if (p
->procname
&& strcmp(p
->procname
, s
) == 0)
1786 /* see if attaching q to p would be an improvement */
1787 static void try_attach(struct ctl_table_header
*p
, struct ctl_table_header
*q
)
1789 struct ctl_table
*to
= p
->ctl_table
, *by
= q
->ctl_table
;
1790 struct ctl_table
*next
;
1792 int not_in_parent
= !p
->attached_by
;
1794 while ((next
= is_branch_in(by
, to
)) != NULL
) {
1795 if (by
== q
->attached_by
)
1797 if (to
== p
->attached_by
)
1803 if (is_better
&& not_in_parent
) {
1804 q
->attached_by
= by
;
1805 q
->attached_to
= to
;
1811 * __register_sysctl_paths - register a sysctl hierarchy
1812 * @root: List of sysctl headers to register on
1813 * @namespaces: Data to compute which lists of sysctl entries are visible
1814 * @path: The path to the directory the sysctl table is in.
1815 * @table: the top-level table structure
1817 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1818 * array. A completely 0 filled entry terminates the table.
1820 * The members of the &struct ctl_table structure are used as follows:
1822 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1823 * enter a sysctl file
1825 * data - a pointer to data for use by proc_handler
1827 * maxlen - the maximum size in bytes of the data
1829 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1831 * child - a pointer to the child sysctl table if this entry is a directory, or
1834 * proc_handler - the text handler routine (described below)
1836 * de - for internal use by the sysctl routines
1838 * extra1, extra2 - extra pointers usable by the proc handler routines
1840 * Leaf nodes in the sysctl tree will be represented by a single file
1841 * under /proc; non-leaf nodes will be represented by directories.
1843 * sysctl(2) can automatically manage read and write requests through
1844 * the sysctl table. The data and maxlen fields of the ctl_table
1845 * struct enable minimal validation of the values being written to be
1846 * performed, and the mode field allows minimal authentication.
1848 * There must be a proc_handler routine for any terminal nodes
1849 * mirrored under /proc/sys (non-terminals are handled by a built-in
1850 * directory handler). Several default handlers are available to
1851 * cover common cases -
1853 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1854 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1855 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1857 * It is the handler's job to read the input buffer from user memory
1858 * and process it. The handler should return 0 on success.
1860 * This routine returns %NULL on a failure to register, and a pointer
1861 * to the table header on success.
1863 struct ctl_table_header
*__register_sysctl_paths(
1864 struct ctl_table_root
*root
,
1865 struct nsproxy
*namespaces
,
1866 const struct ctl_path
*path
, struct ctl_table
*table
)
1868 struct ctl_table_header
*header
;
1869 struct ctl_table
*new, **prevp
;
1870 unsigned int n
, npath
;
1871 struct ctl_table_set
*set
;
1873 /* Count the path components */
1874 for (npath
= 0; path
[npath
].procname
; ++npath
)
1878 * For each path component, allocate a 2-element ctl_table array.
1879 * The first array element will be filled with the sysctl entry
1880 * for this, the second will be the sentinel (procname == 0).
1882 * We allocate everything in one go so that we don't have to
1883 * worry about freeing additional memory in unregister_sysctl_table.
1885 header
= kzalloc(sizeof(struct ctl_table_header
) +
1886 (2 * npath
* sizeof(struct ctl_table
)), GFP_KERNEL
);
1890 new = (struct ctl_table
*) (header
+ 1);
1892 /* Now connect the dots */
1893 prevp
= &header
->ctl_table
;
1894 for (n
= 0; n
< npath
; ++n
, ++path
) {
1895 /* Copy the procname */
1896 new->procname
= path
->procname
;
1900 prevp
= &new->child
;
1905 header
->ctl_table_arg
= table
;
1907 INIT_LIST_HEAD(&header
->ctl_entry
);
1909 header
->unregistering
= NULL
;
1910 header
->root
= root
;
1911 sysctl_set_parent(NULL
, header
->ctl_table
);
1913 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1914 if (sysctl_check_table(namespaces
, header
->ctl_table
)) {
1919 spin_lock(&sysctl_lock
);
1920 header
->set
= lookup_header_set(root
, namespaces
);
1921 header
->attached_by
= header
->ctl_table
;
1922 header
->attached_to
= root_table
;
1923 header
->parent
= &root_table_header
;
1924 for (set
= header
->set
; set
; set
= set
->parent
) {
1925 struct ctl_table_header
*p
;
1926 list_for_each_entry(p
, &set
->list
, ctl_entry
) {
1927 if (p
->unregistering
)
1929 try_attach(p
, header
);
1932 header
->parent
->count
++;
1933 list_add_tail(&header
->ctl_entry
, &header
->set
->list
);
1934 spin_unlock(&sysctl_lock
);
1940 * register_sysctl_table_path - register a sysctl table hierarchy
1941 * @path: The path to the directory the sysctl table is in.
1942 * @table: the top-level table structure
1944 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1945 * array. A completely 0 filled entry terminates the table.
1947 * See __register_sysctl_paths for more details.
1949 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1950 struct ctl_table
*table
)
1952 return __register_sysctl_paths(&sysctl_table_root
, current
->nsproxy
,
1957 * register_sysctl_table - register a sysctl table hierarchy
1958 * @table: the top-level table structure
1960 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1961 * array. A completely 0 filled entry terminates the table.
1963 * See register_sysctl_paths for more details.
1965 struct ctl_table_header
*register_sysctl_table(struct ctl_table
*table
)
1967 static const struct ctl_path null_path
[] = { {} };
1969 return register_sysctl_paths(null_path
, table
);
1973 * unregister_sysctl_table - unregister a sysctl table hierarchy
1974 * @header: the header returned from register_sysctl_table
1976 * Unregisters the sysctl table and all children. proc entries may not
1977 * actually be removed until they are no longer used by anyone.
1979 void unregister_sysctl_table(struct ctl_table_header
* header
)
1986 spin_lock(&sysctl_lock
);
1987 start_unregistering(header
);
1988 if (!--header
->parent
->count
) {
1990 kfree_rcu(header
->parent
, rcu
);
1992 if (!--header
->count
)
1993 kfree_rcu(header
, rcu
);
1994 spin_unlock(&sysctl_lock
);
1997 int sysctl_is_seen(struct ctl_table_header
*p
)
1999 struct ctl_table_set
*set
= p
->set
;
2001 spin_lock(&sysctl_lock
);
2002 if (p
->unregistering
)
2004 else if (!set
->is_seen
)
2007 res
= set
->is_seen(set
);
2008 spin_unlock(&sysctl_lock
);
2012 void setup_sysctl_set(struct ctl_table_set
*p
,
2013 struct ctl_table_set
*parent
,
2014 int (*is_seen
)(struct ctl_table_set
*))
2016 INIT_LIST_HEAD(&p
->list
);
2017 p
->parent
= parent
? parent
: &sysctl_table_root
.default_set
;
2018 p
->is_seen
= is_seen
;
2021 #else /* !CONFIG_SYSCTL */
2022 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
2027 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
2028 struct ctl_table
*table
)
2033 void unregister_sysctl_table(struct ctl_table_header
* table
)
2037 void setup_sysctl_set(struct ctl_table_set
*p
,
2038 struct ctl_table_set
*parent
,
2039 int (*is_seen
)(struct ctl_table_set
*))
2043 void sysctl_head_put(struct ctl_table_header
*head
)
2047 #endif /* CONFIG_SYSCTL */
2053 #ifdef CONFIG_PROC_SYSCTL
2055 static int _proc_do_string(void* data
, int maxlen
, int write
,
2056 void __user
*buffer
,
2057 size_t *lenp
, loff_t
*ppos
)
2063 if (!data
|| !maxlen
|| !*lenp
) {
2071 while (len
< *lenp
) {
2072 if (get_user(c
, p
++))
2074 if (c
== 0 || c
== '\n')
2080 if(copy_from_user(data
, buffer
, len
))
2082 ((char *) data
)[len
] = 0;
2100 if(copy_to_user(buffer
, data
, len
))
2103 if(put_user('\n', ((char __user
*) buffer
) + len
))
2114 * proc_dostring - read a string sysctl
2115 * @table: the sysctl table
2116 * @write: %TRUE if this is a write to the sysctl file
2117 * @buffer: the user buffer
2118 * @lenp: the size of the user buffer
2119 * @ppos: file position
2121 * Reads/writes a string from/to the user buffer. If the kernel
2122 * buffer provided is not large enough to hold the string, the
2123 * string is truncated. The copied string is %NULL-terminated.
2124 * If the string is being read by the user process, it is copied
2125 * and a newline '\n' is added. It is truncated if the buffer is
2128 * Returns 0 on success.
2130 int proc_dostring(struct ctl_table
*table
, int write
,
2131 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2133 return _proc_do_string(table
->data
, table
->maxlen
, write
,
2134 buffer
, lenp
, ppos
);
2137 static size_t proc_skip_spaces(char **buf
)
2140 char *tmp
= skip_spaces(*buf
);
2146 static void proc_skip_char(char **buf
, size_t *size
, const char v
)
2156 #define TMPBUFLEN 22
2158 * proc_get_long - reads an ASCII formatted integer from a user buffer
2160 * @buf: a kernel buffer
2161 * @size: size of the kernel buffer
2162 * @val: this is where the number will be stored
2163 * @neg: set to %TRUE if number is negative
2164 * @perm_tr: a vector which contains the allowed trailers
2165 * @perm_tr_len: size of the perm_tr vector
2166 * @tr: pointer to store the trailer character
2168 * In case of success %0 is returned and @buf and @size are updated with
2169 * the amount of bytes read. If @tr is non-NULL and a trailing
2170 * character exists (size is non-zero after returning from this
2171 * function), @tr is updated with the trailing character.
2173 static int proc_get_long(char **buf
, size_t *size
,
2174 unsigned long *val
, bool *neg
,
2175 const char *perm_tr
, unsigned perm_tr_len
, char *tr
)
2178 char *p
, tmp
[TMPBUFLEN
];
2184 if (len
> TMPBUFLEN
- 1)
2185 len
= TMPBUFLEN
- 1;
2187 memcpy(tmp
, *buf
, len
);
2191 if (*p
== '-' && *size
> 1) {
2199 *val
= simple_strtoul(p
, &p
, 0);
2203 /* We don't know if the next char is whitespace thus we may accept
2204 * invalid integers (e.g. 1234...a) or two integers instead of one
2205 * (e.g. 123...1). So lets not allow such large numbers. */
2206 if (len
== TMPBUFLEN
- 1)
2209 if (len
< *size
&& perm_tr_len
&& !memchr(perm_tr
, *p
, perm_tr_len
))
2212 if (tr
&& (len
< *size
))
2222 * proc_put_long - converts an integer to a decimal ASCII formatted string
2224 * @buf: the user buffer
2225 * @size: the size of the user buffer
2226 * @val: the integer to be converted
2227 * @neg: sign of the number, %TRUE for negative
2229 * In case of success %0 is returned and @buf and @size are updated with
2230 * the amount of bytes written.
2232 static int proc_put_long(void __user
**buf
, size_t *size
, unsigned long val
,
2236 char tmp
[TMPBUFLEN
], *p
= tmp
;
2238 sprintf(p
, "%s%lu", neg
? "-" : "", val
);
2242 if (copy_to_user(*buf
, tmp
, len
))
2250 static int proc_put_char(void __user
**buf
, size_t *size
, char c
)
2253 char __user
**buffer
= (char __user
**)buf
;
2254 if (put_user(c
, *buffer
))
2256 (*size
)--, (*buffer
)++;
2262 static int do_proc_dointvec_conv(bool *negp
, unsigned long *lvalp
,
2264 int write
, void *data
)
2267 *valp
= *negp
? -*lvalp
: *lvalp
;
2272 *lvalp
= (unsigned long)-val
;
2275 *lvalp
= (unsigned long)val
;
2281 static const char proc_wspace_sep
[] = { ' ', '\t', '\n' };
2283 static int __do_proc_dointvec(void *tbl_data
, struct ctl_table
*table
,
2284 int write
, void __user
*buffer
,
2285 size_t *lenp
, loff_t
*ppos
,
2286 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2287 int write
, void *data
),
2290 int *i
, vleft
, first
= 1, err
= 0;
2291 unsigned long page
= 0;
2295 if (!tbl_data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2300 i
= (int *) tbl_data
;
2301 vleft
= table
->maxlen
/ sizeof(*i
);
2305 conv
= do_proc_dointvec_conv
;
2308 if (left
> PAGE_SIZE
- 1)
2309 left
= PAGE_SIZE
- 1;
2310 page
= __get_free_page(GFP_TEMPORARY
);
2311 kbuf
= (char *) page
;
2314 if (copy_from_user(kbuf
, buffer
, left
)) {
2321 for (; left
&& vleft
--; i
++, first
=0) {
2326 left
-= proc_skip_spaces(&kbuf
);
2330 err
= proc_get_long(&kbuf
, &left
, &lval
, &neg
,
2332 sizeof(proc_wspace_sep
), NULL
);
2335 if (conv(&neg
, &lval
, i
, 1, data
)) {
2340 if (conv(&neg
, &lval
, i
, 0, data
)) {
2345 err
= proc_put_char(&buffer
, &left
, '\t');
2348 err
= proc_put_long(&buffer
, &left
, lval
, neg
);
2354 if (!write
&& !first
&& left
&& !err
)
2355 err
= proc_put_char(&buffer
, &left
, '\n');
2356 if (write
&& !err
&& left
)
2357 left
-= proc_skip_spaces(&kbuf
);
2362 return err
? : -EINVAL
;
2369 static int do_proc_dointvec(struct ctl_table
*table
, int write
,
2370 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
2371 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2372 int write
, void *data
),
2375 return __do_proc_dointvec(table
->data
, table
, write
,
2376 buffer
, lenp
, ppos
, conv
, data
);
2380 * proc_dointvec - read a vector of integers
2381 * @table: the sysctl table
2382 * @write: %TRUE if this is a write to the sysctl file
2383 * @buffer: the user buffer
2384 * @lenp: the size of the user buffer
2385 * @ppos: file position
2387 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2388 * values from/to the user buffer, treated as an ASCII string.
2390 * Returns 0 on success.
2392 int proc_dointvec(struct ctl_table
*table
, int write
,
2393 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2395 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2400 * Taint values can only be increased
2401 * This means we can safely use a temporary.
2403 static int proc_taint(struct ctl_table
*table
, int write
,
2404 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2407 unsigned long tmptaint
= get_taint();
2410 if (write
&& !capable(CAP_SYS_ADMIN
))
2415 err
= proc_doulongvec_minmax(&t
, write
, buffer
, lenp
, ppos
);
2421 * Poor man's atomic or. Not worth adding a primitive
2422 * to everyone's atomic.h for this
2425 for (i
= 0; i
< BITS_PER_LONG
&& tmptaint
>> i
; i
++) {
2426 if ((tmptaint
>> i
) & 1)
2434 #ifdef CONFIG_PRINTK
2435 static int proc_dmesg_restrict(struct ctl_table
*table
, int write
,
2436 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2438 if (write
&& !capable(CAP_SYS_ADMIN
))
2441 return proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
2445 struct do_proc_dointvec_minmax_conv_param
{
2450 static int do_proc_dointvec_minmax_conv(bool *negp
, unsigned long *lvalp
,
2452 int write
, void *data
)
2454 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
2456 int val
= *negp
? -*lvalp
: *lvalp
;
2457 if ((param
->min
&& *param
->min
> val
) ||
2458 (param
->max
&& *param
->max
< val
))
2465 *lvalp
= (unsigned long)-val
;
2468 *lvalp
= (unsigned long)val
;
2475 * proc_dointvec_minmax - read a vector of integers with min/max values
2476 * @table: the sysctl table
2477 * @write: %TRUE if this is a write to the sysctl file
2478 * @buffer: the user buffer
2479 * @lenp: the size of the user buffer
2480 * @ppos: file position
2482 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2483 * values from/to the user buffer, treated as an ASCII string.
2485 * This routine will ensure the values are within the range specified by
2486 * table->extra1 (min) and table->extra2 (max).
2488 * Returns 0 on success.
2490 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2491 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2493 struct do_proc_dointvec_minmax_conv_param param
= {
2494 .min
= (int *) table
->extra1
,
2495 .max
= (int *) table
->extra2
,
2497 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2498 do_proc_dointvec_minmax_conv
, ¶m
);
2501 static int __do_proc_doulongvec_minmax(void *data
, struct ctl_table
*table
, int write
,
2502 void __user
*buffer
,
2503 size_t *lenp
, loff_t
*ppos
,
2504 unsigned long convmul
,
2505 unsigned long convdiv
)
2507 unsigned long *i
, *min
, *max
;
2508 int vleft
, first
= 1, err
= 0;
2509 unsigned long page
= 0;
2513 if (!data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2518 i
= (unsigned long *) data
;
2519 min
= (unsigned long *) table
->extra1
;
2520 max
= (unsigned long *) table
->extra2
;
2521 vleft
= table
->maxlen
/ sizeof(unsigned long);
2525 if (left
> PAGE_SIZE
- 1)
2526 left
= PAGE_SIZE
- 1;
2527 page
= __get_free_page(GFP_TEMPORARY
);
2528 kbuf
= (char *) page
;
2531 if (copy_from_user(kbuf
, buffer
, left
)) {
2538 for (; left
&& vleft
--; i
++, first
= 0) {
2544 left
-= proc_skip_spaces(&kbuf
);
2546 err
= proc_get_long(&kbuf
, &left
, &val
, &neg
,
2548 sizeof(proc_wspace_sep
), NULL
);
2553 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2557 val
= convdiv
* (*i
) / convmul
;
2559 err
= proc_put_char(&buffer
, &left
, '\t');
2560 err
= proc_put_long(&buffer
, &left
, val
, false);
2566 if (!write
&& !first
&& left
&& !err
)
2567 err
= proc_put_char(&buffer
, &left
, '\n');
2569 left
-= proc_skip_spaces(&kbuf
);
2574 return err
? : -EINVAL
;
2581 static int do_proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2582 void __user
*buffer
,
2583 size_t *lenp
, loff_t
*ppos
,
2584 unsigned long convmul
,
2585 unsigned long convdiv
)
2587 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2588 buffer
, lenp
, ppos
, convmul
, convdiv
);
2592 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2593 * @table: the sysctl table
2594 * @write: %TRUE if this is a write to the sysctl file
2595 * @buffer: the user buffer
2596 * @lenp: the size of the user buffer
2597 * @ppos: file position
2599 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2600 * values from/to the user buffer, treated as an ASCII string.
2602 * This routine will ensure the values are within the range specified by
2603 * table->extra1 (min) and table->extra2 (max).
2605 * Returns 0 on success.
2607 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2608 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2610 return do_proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
, 1l, 1l);
2614 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2615 * @table: the sysctl table
2616 * @write: %TRUE if this is a write to the sysctl file
2617 * @buffer: the user buffer
2618 * @lenp: the size of the user buffer
2619 * @ppos: file position
2621 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2622 * values from/to the user buffer, treated as an ASCII string. The values
2623 * are treated as milliseconds, and converted to jiffies when they are stored.
2625 * This routine will ensure the values are within the range specified by
2626 * table->extra1 (min) and table->extra2 (max).
2628 * Returns 0 on success.
2630 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2631 void __user
*buffer
,
2632 size_t *lenp
, loff_t
*ppos
)
2634 return do_proc_doulongvec_minmax(table
, write
, buffer
,
2635 lenp
, ppos
, HZ
, 1000l);
2639 static int do_proc_dointvec_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2641 int write
, void *data
)
2644 if (*lvalp
> LONG_MAX
/ HZ
)
2646 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2652 lval
= (unsigned long)-val
;
2655 lval
= (unsigned long)val
;
2662 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2664 int write
, void *data
)
2667 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2669 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2675 lval
= (unsigned long)-val
;
2678 lval
= (unsigned long)val
;
2680 *lvalp
= jiffies_to_clock_t(lval
);
2685 static int do_proc_dointvec_ms_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2687 int write
, void *data
)
2690 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2696 lval
= (unsigned long)-val
;
2699 lval
= (unsigned long)val
;
2701 *lvalp
= jiffies_to_msecs(lval
);
2707 * proc_dointvec_jiffies - read a vector of integers as seconds
2708 * @table: the sysctl table
2709 * @write: %TRUE if this is a write to the sysctl file
2710 * @buffer: the user buffer
2711 * @lenp: the size of the user buffer
2712 * @ppos: file position
2714 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715 * values from/to the user buffer, treated as an ASCII string.
2716 * The values read are assumed to be in seconds, and are converted into
2719 * Returns 0 on success.
2721 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2722 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2724 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2725 do_proc_dointvec_jiffies_conv
,NULL
);
2729 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2730 * @table: the sysctl table
2731 * @write: %TRUE if this is a write to the sysctl file
2732 * @buffer: the user buffer
2733 * @lenp: the size of the user buffer
2734 * @ppos: pointer to the file position
2736 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2737 * values from/to the user buffer, treated as an ASCII string.
2738 * The values read are assumed to be in 1/USER_HZ seconds, and
2739 * are converted into jiffies.
2741 * Returns 0 on success.
2743 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2744 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2746 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2747 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2751 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2752 * @table: the sysctl table
2753 * @write: %TRUE if this is a write to the sysctl file
2754 * @buffer: the user buffer
2755 * @lenp: the size of the user buffer
2756 * @ppos: file position
2757 * @ppos: the current position in the file
2759 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2760 * values from/to the user buffer, treated as an ASCII string.
2761 * The values read are assumed to be in 1/1000 seconds, and
2762 * are converted into jiffies.
2764 * Returns 0 on success.
2766 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2767 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2769 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2770 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2773 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
2774 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2776 struct pid
*new_pid
;
2780 tmp
= pid_vnr(cad_pid
);
2782 r
= __do_proc_dointvec(&tmp
, table
, write
, buffer
,
2783 lenp
, ppos
, NULL
, NULL
);
2787 new_pid
= find_get_pid(tmp
);
2791 put_pid(xchg(&cad_pid
, new_pid
));
2796 * proc_do_large_bitmap - read/write from/to a large bitmap
2797 * @table: the sysctl table
2798 * @write: %TRUE if this is a write to the sysctl file
2799 * @buffer: the user buffer
2800 * @lenp: the size of the user buffer
2801 * @ppos: file position
2803 * The bitmap is stored at table->data and the bitmap length (in bits)
2806 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2807 * large bitmaps may be represented in a compact manner. Writing into
2808 * the file will clear the bitmap then update it with the given input.
2810 * Returns 0 on success.
2812 int proc_do_large_bitmap(struct ctl_table
*table
, int write
,
2813 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2817 size_t left
= *lenp
;
2818 unsigned long bitmap_len
= table
->maxlen
;
2819 unsigned long *bitmap
= (unsigned long *) table
->data
;
2820 unsigned long *tmp_bitmap
= NULL
;
2821 char tr_a
[] = { '-', ',', '\n' }, tr_b
[] = { ',', '\n', 0 }, c
;
2823 if (!bitmap_len
|| !left
|| (*ppos
&& !write
)) {
2829 unsigned long page
= 0;
2832 if (left
> PAGE_SIZE
- 1)
2833 left
= PAGE_SIZE
- 1;
2835 page
= __get_free_page(GFP_TEMPORARY
);
2836 kbuf
= (char *) page
;
2839 if (copy_from_user(kbuf
, buffer
, left
)) {
2845 tmp_bitmap
= kzalloc(BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long),
2851 proc_skip_char(&kbuf
, &left
, '\n');
2852 while (!err
&& left
) {
2853 unsigned long val_a
, val_b
;
2856 err
= proc_get_long(&kbuf
, &left
, &val_a
, &neg
, tr_a
,
2860 if (val_a
>= bitmap_len
|| neg
) {
2872 err
= proc_get_long(&kbuf
, &left
, &val_b
,
2873 &neg
, tr_b
, sizeof(tr_b
),
2877 if (val_b
>= bitmap_len
|| neg
||
2888 while (val_a
<= val_b
)
2889 set_bit(val_a
++, tmp_bitmap
);
2892 proc_skip_char(&kbuf
, &left
, '\n');
2896 unsigned long bit_a
, bit_b
= 0;
2899 bit_a
= find_next_bit(bitmap
, bitmap_len
, bit_b
);
2900 if (bit_a
>= bitmap_len
)
2902 bit_b
= find_next_zero_bit(bitmap
, bitmap_len
,
2906 err
= proc_put_char(&buffer
, &left
, ',');
2910 err
= proc_put_long(&buffer
, &left
, bit_a
, false);
2913 if (bit_a
!= bit_b
) {
2914 err
= proc_put_char(&buffer
, &left
, '-');
2917 err
= proc_put_long(&buffer
, &left
, bit_b
, false);
2925 err
= proc_put_char(&buffer
, &left
, '\n');
2931 bitmap_or(bitmap
, bitmap
, tmp_bitmap
, bitmap_len
);
2933 memcpy(bitmap
, tmp_bitmap
,
2934 BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long));
2946 #else /* CONFIG_PROC_SYSCTL */
2948 int proc_dostring(struct ctl_table
*table
, int write
,
2949 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2954 int proc_dointvec(struct ctl_table
*table
, int write
,
2955 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2960 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2961 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2966 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2967 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2972 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2973 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2978 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2979 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2984 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2985 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2990 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2991 void __user
*buffer
,
2992 size_t *lenp
, loff_t
*ppos
)
2998 #endif /* CONFIG_PROC_SYSCTL */
3001 * No sense putting this after each symbol definition, twice,
3002 * exception granted :-)
3004 EXPORT_SYMBOL(proc_dointvec
);
3005 EXPORT_SYMBOL(proc_dointvec_jiffies
);
3006 EXPORT_SYMBOL(proc_dointvec_minmax
);
3007 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
3008 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
3009 EXPORT_SYMBOL(proc_dostring
);
3010 EXPORT_SYMBOL(proc_doulongvec_minmax
);
3011 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
3012 EXPORT_SYMBOL(register_sysctl_table
);
3013 EXPORT_SYMBOL(register_sysctl_paths
);
3014 EXPORT_SYMBOL(unregister_sysctl_table
);