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>
61 #include <asm/uaccess.h>
62 #include <asm/processor.h>
66 #include <asm/stacktrace.h>
69 #ifdef CONFIG_BSD_PROCESS_ACCT
70 #include <linux/acct.h>
72 #ifdef CONFIG_RT_MUTEXES
73 #include <linux/rtmutex.h>
75 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
76 #include <linux/lockdep.h>
78 #ifdef CONFIG_CHR_DEV_SG
82 #ifdef CONFIG_LOCKUP_DETECTOR
83 #include <linux/nmi.h>
87 #if defined(CONFIG_SYSCTL)
89 /* External variables not in a header file. */
90 extern int sysctl_overcommit_memory
;
91 extern int sysctl_overcommit_ratio
;
92 extern int max_threads
;
93 extern int core_uses_pid
;
94 extern int suid_dumpable
;
95 extern char core_pattern
[];
96 extern unsigned int core_pipe_limit
;
98 extern int min_free_kbytes
;
99 extern int pid_max_min
, pid_max_max
;
100 extern int sysctl_drop_caches
;
101 extern int percpu_pagelist_fraction
;
102 extern int compat_log
;
103 extern int latencytop_enabled
;
104 extern int sysctl_nr_open_min
, sysctl_nr_open_max
;
106 extern int sysctl_nr_trim_pages
;
109 extern int blk_iopoll_enabled
;
112 /* Constants used for minimum and maximum */
113 #ifdef CONFIG_LOCKUP_DETECTOR
114 static int sixty
= 60;
115 static int neg_one
= -1;
119 static int __maybe_unused one
= 1;
120 static int __maybe_unused two
= 2;
121 static int __maybe_unused three
= 3;
122 static unsigned long one_ul
= 1;
123 static int one_hundred
= 100;
125 static int ten_thousand
= 10000;
128 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
129 static unsigned long dirty_bytes_min
= 2 * PAGE_SIZE
;
131 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
132 static int maxolduid
= 65535;
133 static int minolduid
;
134 static int min_percpu_pagelist_fract
= 8;
136 static int ngroups_max
= NGROUPS_MAX
;
138 #ifdef CONFIG_INOTIFY_USER
139 #include <linux/inotify.h>
142 #include <asm/system.h>
145 #ifdef CONFIG_SPARC64
146 extern int sysctl_tsb_ratio
;
150 extern int pwrsw_enabled
;
151 extern int unaligned_enabled
;
155 #ifdef CONFIG_MATHEMU
156 extern int sysctl_ieee_emulation_warnings
;
158 extern int sysctl_userprocess_debug
;
159 extern int spin_retry
;
163 extern int no_unaligned_warning
;
164 extern int unaligned_dump_stack
;
167 #ifdef CONFIG_PROC_SYSCTL
168 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
169 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
170 static int proc_taint(struct ctl_table
*table
, int write
,
171 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
175 static int proc_dmesg_restrict(struct ctl_table
*table
, int write
,
176 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
179 #ifdef CONFIG_MAGIC_SYSRQ
180 /* Note: sysrq code uses it's own private copy */
181 static int __sysrq_enabled
= SYSRQ_DEFAULT_ENABLE
;
183 static int sysrq_sysctl_handler(ctl_table
*table
, int write
,
184 void __user
*buffer
, size_t *lenp
,
189 error
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
194 sysrq_toggle_support(__sysrq_enabled
);
201 static struct ctl_table root_table
[];
202 static struct ctl_table_root sysctl_table_root
;
203 static struct ctl_table_header root_table_header
= {
205 .ctl_table
= root_table
,
206 .ctl_entry
= LIST_HEAD_INIT(sysctl_table_root
.default_set
.list
),}},
207 .root
= &sysctl_table_root
,
208 .set
= &sysctl_table_root
.default_set
,
210 static struct ctl_table_root sysctl_table_root
= {
211 .root_list
= LIST_HEAD_INIT(sysctl_table_root
.root_list
),
212 .default_set
.list
= LIST_HEAD_INIT(root_table_header
.ctl_entry
),
215 static struct ctl_table kern_table
[];
216 static struct ctl_table vm_table
[];
217 static struct ctl_table fs_table
[];
218 static struct ctl_table debug_table
[];
219 static struct ctl_table dev_table
[];
220 extern struct ctl_table random_table
[];
222 extern struct ctl_table epoll_table
[];
225 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
226 int sysctl_legacy_va_layout
;
229 /* The default sysctl tables: */
231 static struct ctl_table root_table
[] = {
233 .procname
= "kernel",
250 .child
= debug_table
,
260 #ifdef CONFIG_SCHED_DEBUG
261 static int min_sched_granularity_ns
= 100000; /* 100 usecs */
262 static int max_sched_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
263 static int min_wakeup_granularity_ns
; /* 0 usecs */
264 static int max_wakeup_granularity_ns
= NSEC_PER_SEC
; /* 1 second */
265 static int min_sched_tunable_scaling
= SCHED_TUNABLESCALING_NONE
;
266 static int max_sched_tunable_scaling
= SCHED_TUNABLESCALING_END
-1;
269 #ifdef CONFIG_COMPACTION
270 static int min_extfrag_threshold
;
271 static int max_extfrag_threshold
= 1000;
274 static struct ctl_table kern_table
[] = {
276 .procname
= "sched_child_runs_first",
277 .data
= &sysctl_sched_child_runs_first
,
278 .maxlen
= sizeof(unsigned int),
280 .proc_handler
= proc_dointvec
,
282 #ifdef CONFIG_SCHED_DEBUG
284 .procname
= "sched_min_granularity_ns",
285 .data
= &sysctl_sched_min_granularity
,
286 .maxlen
= sizeof(unsigned int),
288 .proc_handler
= sched_proc_update_handler
,
289 .extra1
= &min_sched_granularity_ns
,
290 .extra2
= &max_sched_granularity_ns
,
293 .procname
= "sched_latency_ns",
294 .data
= &sysctl_sched_latency
,
295 .maxlen
= sizeof(unsigned int),
297 .proc_handler
= sched_proc_update_handler
,
298 .extra1
= &min_sched_granularity_ns
,
299 .extra2
= &max_sched_granularity_ns
,
302 .procname
= "sched_wakeup_granularity_ns",
303 .data
= &sysctl_sched_wakeup_granularity
,
304 .maxlen
= sizeof(unsigned int),
306 .proc_handler
= sched_proc_update_handler
,
307 .extra1
= &min_wakeup_granularity_ns
,
308 .extra2
= &max_wakeup_granularity_ns
,
311 .procname
= "sched_tunable_scaling",
312 .data
= &sysctl_sched_tunable_scaling
,
313 .maxlen
= sizeof(enum sched_tunable_scaling
),
315 .proc_handler
= sched_proc_update_handler
,
316 .extra1
= &min_sched_tunable_scaling
,
317 .extra2
= &max_sched_tunable_scaling
,
320 .procname
= "sched_migration_cost",
321 .data
= &sysctl_sched_migration_cost
,
322 .maxlen
= sizeof(unsigned int),
324 .proc_handler
= proc_dointvec
,
327 .procname
= "sched_nr_migrate",
328 .data
= &sysctl_sched_nr_migrate
,
329 .maxlen
= sizeof(unsigned int),
331 .proc_handler
= proc_dointvec
,
334 .procname
= "sched_time_avg",
335 .data
= &sysctl_sched_time_avg
,
336 .maxlen
= sizeof(unsigned int),
338 .proc_handler
= proc_dointvec
,
341 .procname
= "sched_shares_window",
342 .data
= &sysctl_sched_shares_window
,
343 .maxlen
= sizeof(unsigned int),
345 .proc_handler
= proc_dointvec
,
348 .procname
= "timer_migration",
349 .data
= &sysctl_timer_migration
,
350 .maxlen
= sizeof(unsigned int),
352 .proc_handler
= proc_dointvec_minmax
,
358 .procname
= "sched_rt_period_us",
359 .data
= &sysctl_sched_rt_period
,
360 .maxlen
= sizeof(unsigned int),
362 .proc_handler
= sched_rt_handler
,
365 .procname
= "sched_rt_runtime_us",
366 .data
= &sysctl_sched_rt_runtime
,
367 .maxlen
= sizeof(int),
369 .proc_handler
= sched_rt_handler
,
371 #ifdef CONFIG_SCHED_AUTOGROUP
373 .procname
= "sched_autogroup_enabled",
374 .data
= &sysctl_sched_autogroup_enabled
,
375 .maxlen
= sizeof(unsigned int),
377 .proc_handler
= proc_dointvec_minmax
,
382 #ifdef CONFIG_PROVE_LOCKING
384 .procname
= "prove_locking",
385 .data
= &prove_locking
,
386 .maxlen
= sizeof(int),
388 .proc_handler
= proc_dointvec
,
391 #ifdef CONFIG_LOCK_STAT
393 .procname
= "lock_stat",
395 .maxlen
= sizeof(int),
397 .proc_handler
= proc_dointvec
,
402 .data
= &panic_timeout
,
403 .maxlen
= sizeof(int),
405 .proc_handler
= proc_dointvec
,
408 .procname
= "core_uses_pid",
409 .data
= &core_uses_pid
,
410 .maxlen
= sizeof(int),
412 .proc_handler
= proc_dointvec
,
415 .procname
= "core_pattern",
416 .data
= core_pattern
,
417 .maxlen
= CORENAME_MAX_SIZE
,
419 .proc_handler
= proc_dostring
,
422 .procname
= "core_pipe_limit",
423 .data
= &core_pipe_limit
,
424 .maxlen
= sizeof(unsigned int),
426 .proc_handler
= proc_dointvec
,
428 #ifdef CONFIG_PROC_SYSCTL
430 .procname
= "tainted",
431 .maxlen
= sizeof(long),
433 .proc_handler
= proc_taint
,
436 #ifdef CONFIG_LATENCYTOP
438 .procname
= "latencytop",
439 .data
= &latencytop_enabled
,
440 .maxlen
= sizeof(int),
442 .proc_handler
= proc_dointvec
,
445 #ifdef CONFIG_BLK_DEV_INITRD
447 .procname
= "real-root-dev",
448 .data
= &real_root_dev
,
449 .maxlen
= sizeof(int),
451 .proc_handler
= proc_dointvec
,
455 .procname
= "print-fatal-signals",
456 .data
= &print_fatal_signals
,
457 .maxlen
= sizeof(int),
459 .proc_handler
= proc_dointvec
,
463 .procname
= "reboot-cmd",
464 .data
= reboot_command
,
467 .proc_handler
= proc_dostring
,
470 .procname
= "stop-a",
471 .data
= &stop_a_enabled
,
472 .maxlen
= sizeof (int),
474 .proc_handler
= proc_dointvec
,
477 .procname
= "scons-poweroff",
478 .data
= &scons_pwroff
,
479 .maxlen
= sizeof (int),
481 .proc_handler
= proc_dointvec
,
484 #ifdef CONFIG_SPARC64
486 .procname
= "tsb-ratio",
487 .data
= &sysctl_tsb_ratio
,
488 .maxlen
= sizeof (int),
490 .proc_handler
= proc_dointvec
,
495 .procname
= "soft-power",
496 .data
= &pwrsw_enabled
,
497 .maxlen
= sizeof (int),
499 .proc_handler
= proc_dointvec
,
502 .procname
= "unaligned-trap",
503 .data
= &unaligned_enabled
,
504 .maxlen
= sizeof (int),
506 .proc_handler
= proc_dointvec
,
510 .procname
= "ctrl-alt-del",
512 .maxlen
= sizeof(int),
514 .proc_handler
= proc_dointvec
,
516 #ifdef CONFIG_FUNCTION_TRACER
518 .procname
= "ftrace_enabled",
519 .data
= &ftrace_enabled
,
520 .maxlen
= sizeof(int),
522 .proc_handler
= ftrace_enable_sysctl
,
525 #ifdef CONFIG_STACK_TRACER
527 .procname
= "stack_tracer_enabled",
528 .data
= &stack_tracer_enabled
,
529 .maxlen
= sizeof(int),
531 .proc_handler
= stack_trace_sysctl
,
534 #ifdef CONFIG_TRACING
536 .procname
= "ftrace_dump_on_oops",
537 .data
= &ftrace_dump_on_oops
,
538 .maxlen
= sizeof(int),
540 .proc_handler
= proc_dointvec
,
543 #ifdef CONFIG_MODULES
545 .procname
= "modprobe",
546 .data
= &modprobe_path
,
547 .maxlen
= KMOD_PATH_LEN
,
549 .proc_handler
= proc_dostring
,
552 .procname
= "modules_disabled",
553 .data
= &modules_disabled
,
554 .maxlen
= sizeof(int),
556 /* only handle a transition from default "0" to "1" */
557 .proc_handler
= proc_dointvec_minmax
,
562 #ifdef CONFIG_HOTPLUG
564 .procname
= "hotplug",
565 .data
= &uevent_helper
,
566 .maxlen
= UEVENT_HELPER_PATH_LEN
,
568 .proc_handler
= proc_dostring
,
571 #ifdef CONFIG_CHR_DEV_SG
573 .procname
= "sg-big-buff",
574 .data
= &sg_big_buff
,
575 .maxlen
= sizeof (int),
577 .proc_handler
= proc_dointvec
,
580 #ifdef CONFIG_BSD_PROCESS_ACCT
584 .maxlen
= 3*sizeof(int),
586 .proc_handler
= proc_dointvec
,
589 #ifdef CONFIG_MAGIC_SYSRQ
592 .data
= &__sysrq_enabled
,
593 .maxlen
= sizeof (int),
595 .proc_handler
= sysrq_sysctl_handler
,
598 #ifdef CONFIG_PROC_SYSCTL
600 .procname
= "cad_pid",
602 .maxlen
= sizeof (int),
604 .proc_handler
= proc_do_cad_pid
,
608 .procname
= "threads-max",
609 .data
= &max_threads
,
610 .maxlen
= sizeof(int),
612 .proc_handler
= proc_dointvec
,
615 .procname
= "random",
617 .child
= random_table
,
620 .procname
= "usermodehelper",
622 .child
= usermodehelper_table
,
625 .procname
= "overflowuid",
626 .data
= &overflowuid
,
627 .maxlen
= sizeof(int),
629 .proc_handler
= proc_dointvec_minmax
,
630 .extra1
= &minolduid
,
631 .extra2
= &maxolduid
,
634 .procname
= "overflowgid",
635 .data
= &overflowgid
,
636 .maxlen
= sizeof(int),
638 .proc_handler
= proc_dointvec_minmax
,
639 .extra1
= &minolduid
,
640 .extra2
= &maxolduid
,
643 #ifdef CONFIG_MATHEMU
645 .procname
= "ieee_emulation_warnings",
646 .data
= &sysctl_ieee_emulation_warnings
,
647 .maxlen
= sizeof(int),
649 .proc_handler
= proc_dointvec
,
653 .procname
= "userprocess_debug",
654 .data
= &show_unhandled_signals
,
655 .maxlen
= sizeof(int),
657 .proc_handler
= proc_dointvec
,
661 .procname
= "pid_max",
663 .maxlen
= sizeof (int),
665 .proc_handler
= proc_dointvec_minmax
,
666 .extra1
= &pid_max_min
,
667 .extra2
= &pid_max_max
,
670 .procname
= "panic_on_oops",
671 .data
= &panic_on_oops
,
672 .maxlen
= sizeof(int),
674 .proc_handler
= proc_dointvec
,
676 #if defined CONFIG_PRINTK
678 .procname
= "printk",
679 .data
= &console_loglevel
,
680 .maxlen
= 4*sizeof(int),
682 .proc_handler
= proc_dointvec
,
685 .procname
= "printk_ratelimit",
686 .data
= &printk_ratelimit_state
.interval
,
687 .maxlen
= sizeof(int),
689 .proc_handler
= proc_dointvec_jiffies
,
692 .procname
= "printk_ratelimit_burst",
693 .data
= &printk_ratelimit_state
.burst
,
694 .maxlen
= sizeof(int),
696 .proc_handler
= proc_dointvec
,
699 .procname
= "printk_delay",
700 .data
= &printk_delay_msec
,
701 .maxlen
= sizeof(int),
703 .proc_handler
= proc_dointvec_minmax
,
705 .extra2
= &ten_thousand
,
708 .procname
= "dmesg_restrict",
709 .data
= &dmesg_restrict
,
710 .maxlen
= sizeof(int),
712 .proc_handler
= proc_dointvec_minmax
,
717 .procname
= "kptr_restrict",
718 .data
= &kptr_restrict
,
719 .maxlen
= sizeof(int),
721 .proc_handler
= proc_dmesg_restrict
,
727 .procname
= "ngroups_max",
728 .data
= &ngroups_max
,
729 .maxlen
= sizeof (int),
731 .proc_handler
= proc_dointvec
,
733 #if defined(CONFIG_LOCKUP_DETECTOR)
735 .procname
= "watchdog",
736 .data
= &watchdog_enabled
,
737 .maxlen
= sizeof (int),
739 .proc_handler
= proc_dowatchdog
,
744 .procname
= "watchdog_thresh",
745 .data
= &watchdog_thresh
,
746 .maxlen
= sizeof(int),
748 .proc_handler
= proc_dowatchdog
,
753 .procname
= "softlockup_panic",
754 .data
= &softlockup_panic
,
755 .maxlen
= sizeof(int),
757 .proc_handler
= proc_dointvec_minmax
,
762 .procname
= "nmi_watchdog",
763 .data
= &watchdog_enabled
,
764 .maxlen
= sizeof (int),
766 .proc_handler
= proc_dowatchdog
,
771 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
773 .procname
= "unknown_nmi_panic",
774 .data
= &unknown_nmi_panic
,
775 .maxlen
= sizeof (int),
777 .proc_handler
= proc_dointvec
,
780 #if defined(CONFIG_X86)
782 .procname
= "panic_on_unrecovered_nmi",
783 .data
= &panic_on_unrecovered_nmi
,
784 .maxlen
= sizeof(int),
786 .proc_handler
= proc_dointvec
,
789 .procname
= "panic_on_io_nmi",
790 .data
= &panic_on_io_nmi
,
791 .maxlen
= sizeof(int),
793 .proc_handler
= proc_dointvec
,
796 .procname
= "bootloader_type",
797 .data
= &bootloader_type
,
798 .maxlen
= sizeof (int),
800 .proc_handler
= proc_dointvec
,
803 .procname
= "bootloader_version",
804 .data
= &bootloader_version
,
805 .maxlen
= sizeof (int),
807 .proc_handler
= proc_dointvec
,
810 .procname
= "kstack_depth_to_print",
811 .data
= &kstack_depth_to_print
,
812 .maxlen
= sizeof(int),
814 .proc_handler
= proc_dointvec
,
817 .procname
= "io_delay_type",
818 .data
= &io_delay_type
,
819 .maxlen
= sizeof(int),
821 .proc_handler
= proc_dointvec
,
824 #if defined(CONFIG_MMU)
826 .procname
= "randomize_va_space",
827 .data
= &randomize_va_space
,
828 .maxlen
= sizeof(int),
830 .proc_handler
= proc_dointvec
,
833 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
835 .procname
= "spin_retry",
837 .maxlen
= sizeof (int),
839 .proc_handler
= proc_dointvec
,
842 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
844 .procname
= "acpi_video_flags",
845 .data
= &acpi_realmode_flags
,
846 .maxlen
= sizeof (unsigned long),
848 .proc_handler
= proc_doulongvec_minmax
,
853 .procname
= "ignore-unaligned-usertrap",
854 .data
= &no_unaligned_warning
,
855 .maxlen
= sizeof (int),
857 .proc_handler
= proc_dointvec
,
860 .procname
= "unaligned-dump-stack",
861 .data
= &unaligned_dump_stack
,
862 .maxlen
= sizeof (int),
864 .proc_handler
= proc_dointvec
,
867 #ifdef CONFIG_DETECT_HUNG_TASK
869 .procname
= "hung_task_panic",
870 .data
= &sysctl_hung_task_panic
,
871 .maxlen
= sizeof(int),
873 .proc_handler
= proc_dointvec_minmax
,
878 .procname
= "hung_task_check_count",
879 .data
= &sysctl_hung_task_check_count
,
880 .maxlen
= sizeof(unsigned long),
882 .proc_handler
= proc_doulongvec_minmax
,
885 .procname
= "hung_task_timeout_secs",
886 .data
= &sysctl_hung_task_timeout_secs
,
887 .maxlen
= sizeof(unsigned long),
889 .proc_handler
= proc_dohung_task_timeout_secs
,
892 .procname
= "hung_task_warnings",
893 .data
= &sysctl_hung_task_warnings
,
894 .maxlen
= sizeof(unsigned long),
896 .proc_handler
= proc_doulongvec_minmax
,
901 .procname
= "compat-log",
903 .maxlen
= sizeof (int),
905 .proc_handler
= proc_dointvec
,
908 #ifdef CONFIG_RT_MUTEXES
910 .procname
= "max_lock_depth",
911 .data
= &max_lock_depth
,
912 .maxlen
= sizeof(int),
914 .proc_handler
= proc_dointvec
,
918 .procname
= "poweroff_cmd",
919 .data
= &poweroff_cmd
,
920 .maxlen
= POWEROFF_CMD_PATH_LEN
,
922 .proc_handler
= proc_dostring
,
928 .child
= key_sysctls
,
931 #ifdef CONFIG_RCU_TORTURE_TEST
933 .procname
= "rcutorture_runnable",
934 .data
= &rcutorture_runnable
,
935 .maxlen
= sizeof(int),
937 .proc_handler
= proc_dointvec
,
940 #ifdef CONFIG_PERF_EVENTS
942 .procname
= "perf_event_paranoid",
943 .data
= &sysctl_perf_event_paranoid
,
944 .maxlen
= sizeof(sysctl_perf_event_paranoid
),
946 .proc_handler
= proc_dointvec
,
949 .procname
= "perf_event_mlock_kb",
950 .data
= &sysctl_perf_event_mlock
,
951 .maxlen
= sizeof(sysctl_perf_event_mlock
),
953 .proc_handler
= proc_dointvec
,
956 .procname
= "perf_event_max_sample_rate",
957 .data
= &sysctl_perf_event_sample_rate
,
958 .maxlen
= sizeof(sysctl_perf_event_sample_rate
),
960 .proc_handler
= perf_proc_update_handler
,
963 #ifdef CONFIG_KMEMCHECK
965 .procname
= "kmemcheck",
966 .data
= &kmemcheck_enabled
,
967 .maxlen
= sizeof(int),
969 .proc_handler
= proc_dointvec
,
974 .procname
= "blk_iopoll",
975 .data
= &blk_iopoll_enabled
,
976 .maxlen
= sizeof(int),
978 .proc_handler
= proc_dointvec
,
984 static struct ctl_table vm_table
[] = {
986 .procname
= "overcommit_memory",
987 .data
= &sysctl_overcommit_memory
,
988 .maxlen
= sizeof(sysctl_overcommit_memory
),
990 .proc_handler
= proc_dointvec_minmax
,
995 .procname
= "panic_on_oom",
996 .data
= &sysctl_panic_on_oom
,
997 .maxlen
= sizeof(sysctl_panic_on_oom
),
999 .proc_handler
= proc_dointvec_minmax
,
1004 .procname
= "oom_kill_allocating_task",
1005 .data
= &sysctl_oom_kill_allocating_task
,
1006 .maxlen
= sizeof(sysctl_oom_kill_allocating_task
),
1008 .proc_handler
= proc_dointvec
,
1011 .procname
= "oom_dump_tasks",
1012 .data
= &sysctl_oom_dump_tasks
,
1013 .maxlen
= sizeof(sysctl_oom_dump_tasks
),
1015 .proc_handler
= proc_dointvec
,
1018 .procname
= "overcommit_ratio",
1019 .data
= &sysctl_overcommit_ratio
,
1020 .maxlen
= sizeof(sysctl_overcommit_ratio
),
1022 .proc_handler
= proc_dointvec
,
1025 .procname
= "page-cluster",
1026 .data
= &page_cluster
,
1027 .maxlen
= sizeof(int),
1029 .proc_handler
= proc_dointvec_minmax
,
1033 .procname
= "dirty_background_ratio",
1034 .data
= &dirty_background_ratio
,
1035 .maxlen
= sizeof(dirty_background_ratio
),
1037 .proc_handler
= dirty_background_ratio_handler
,
1039 .extra2
= &one_hundred
,
1042 .procname
= "dirty_background_bytes",
1043 .data
= &dirty_background_bytes
,
1044 .maxlen
= sizeof(dirty_background_bytes
),
1046 .proc_handler
= dirty_background_bytes_handler
,
1050 .procname
= "dirty_ratio",
1051 .data
= &vm_dirty_ratio
,
1052 .maxlen
= sizeof(vm_dirty_ratio
),
1054 .proc_handler
= dirty_ratio_handler
,
1056 .extra2
= &one_hundred
,
1059 .procname
= "dirty_bytes",
1060 .data
= &vm_dirty_bytes
,
1061 .maxlen
= sizeof(vm_dirty_bytes
),
1063 .proc_handler
= dirty_bytes_handler
,
1064 .extra1
= &dirty_bytes_min
,
1067 .procname
= "dirty_writeback_centisecs",
1068 .data
= &dirty_writeback_interval
,
1069 .maxlen
= sizeof(dirty_writeback_interval
),
1071 .proc_handler
= dirty_writeback_centisecs_handler
,
1074 .procname
= "dirty_expire_centisecs",
1075 .data
= &dirty_expire_interval
,
1076 .maxlen
= sizeof(dirty_expire_interval
),
1078 .proc_handler
= proc_dointvec_minmax
,
1082 .procname
= "nr_pdflush_threads",
1083 .data
= &nr_pdflush_threads
,
1084 .maxlen
= sizeof nr_pdflush_threads
,
1085 .mode
= 0444 /* read-only*/,
1086 .proc_handler
= proc_dointvec
,
1089 .procname
= "swappiness",
1090 .data
= &vm_swappiness
,
1091 .maxlen
= sizeof(vm_swappiness
),
1093 .proc_handler
= proc_dointvec_minmax
,
1095 .extra2
= &one_hundred
,
1097 #ifdef CONFIG_HUGETLB_PAGE
1099 .procname
= "nr_hugepages",
1101 .maxlen
= sizeof(unsigned long),
1103 .proc_handler
= hugetlb_sysctl_handler
,
1104 .extra1
= (void *)&hugetlb_zero
,
1105 .extra2
= (void *)&hugetlb_infinity
,
1109 .procname
= "nr_hugepages_mempolicy",
1111 .maxlen
= sizeof(unsigned long),
1113 .proc_handler
= &hugetlb_mempolicy_sysctl_handler
,
1114 .extra1
= (void *)&hugetlb_zero
,
1115 .extra2
= (void *)&hugetlb_infinity
,
1119 .procname
= "hugetlb_shm_group",
1120 .data
= &sysctl_hugetlb_shm_group
,
1121 .maxlen
= sizeof(gid_t
),
1123 .proc_handler
= proc_dointvec
,
1126 .procname
= "hugepages_treat_as_movable",
1127 .data
= &hugepages_treat_as_movable
,
1128 .maxlen
= sizeof(int),
1130 .proc_handler
= hugetlb_treat_movable_handler
,
1133 .procname
= "nr_overcommit_hugepages",
1135 .maxlen
= sizeof(unsigned long),
1137 .proc_handler
= hugetlb_overcommit_handler
,
1138 .extra1
= (void *)&hugetlb_zero
,
1139 .extra2
= (void *)&hugetlb_infinity
,
1143 .procname
= "lowmem_reserve_ratio",
1144 .data
= &sysctl_lowmem_reserve_ratio
,
1145 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
1147 .proc_handler
= lowmem_reserve_ratio_sysctl_handler
,
1150 .procname
= "drop_caches",
1151 .data
= &sysctl_drop_caches
,
1152 .maxlen
= sizeof(int),
1154 .proc_handler
= drop_caches_sysctl_handler
,
1158 #ifdef CONFIG_COMPACTION
1160 .procname
= "compact_memory",
1161 .data
= &sysctl_compact_memory
,
1162 .maxlen
= sizeof(int),
1164 .proc_handler
= sysctl_compaction_handler
,
1167 .procname
= "extfrag_threshold",
1168 .data
= &sysctl_extfrag_threshold
,
1169 .maxlen
= sizeof(int),
1171 .proc_handler
= sysctl_extfrag_handler
,
1172 .extra1
= &min_extfrag_threshold
,
1173 .extra2
= &max_extfrag_threshold
,
1176 #endif /* CONFIG_COMPACTION */
1178 .procname
= "min_free_kbytes",
1179 .data
= &min_free_kbytes
,
1180 .maxlen
= sizeof(min_free_kbytes
),
1182 .proc_handler
= min_free_kbytes_sysctl_handler
,
1186 .procname
= "percpu_pagelist_fraction",
1187 .data
= &percpu_pagelist_fraction
,
1188 .maxlen
= sizeof(percpu_pagelist_fraction
),
1190 .proc_handler
= percpu_pagelist_fraction_sysctl_handler
,
1191 .extra1
= &min_percpu_pagelist_fract
,
1195 .procname
= "max_map_count",
1196 .data
= &sysctl_max_map_count
,
1197 .maxlen
= sizeof(sysctl_max_map_count
),
1199 .proc_handler
= proc_dointvec_minmax
,
1204 .procname
= "nr_trim_pages",
1205 .data
= &sysctl_nr_trim_pages
,
1206 .maxlen
= sizeof(sysctl_nr_trim_pages
),
1208 .proc_handler
= proc_dointvec_minmax
,
1213 .procname
= "laptop_mode",
1214 .data
= &laptop_mode
,
1215 .maxlen
= sizeof(laptop_mode
),
1217 .proc_handler
= proc_dointvec_jiffies
,
1220 .procname
= "block_dump",
1221 .data
= &block_dump
,
1222 .maxlen
= sizeof(block_dump
),
1224 .proc_handler
= proc_dointvec
,
1228 .procname
= "vfs_cache_pressure",
1229 .data
= &sysctl_vfs_cache_pressure
,
1230 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
1232 .proc_handler
= proc_dointvec
,
1235 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1237 .procname
= "legacy_va_layout",
1238 .data
= &sysctl_legacy_va_layout
,
1239 .maxlen
= sizeof(sysctl_legacy_va_layout
),
1241 .proc_handler
= proc_dointvec
,
1247 .procname
= "zone_reclaim_mode",
1248 .data
= &zone_reclaim_mode
,
1249 .maxlen
= sizeof(zone_reclaim_mode
),
1251 .proc_handler
= proc_dointvec
,
1255 .procname
= "min_unmapped_ratio",
1256 .data
= &sysctl_min_unmapped_ratio
,
1257 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1259 .proc_handler
= sysctl_min_unmapped_ratio_sysctl_handler
,
1261 .extra2
= &one_hundred
,
1264 .procname
= "min_slab_ratio",
1265 .data
= &sysctl_min_slab_ratio
,
1266 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1268 .proc_handler
= sysctl_min_slab_ratio_sysctl_handler
,
1270 .extra2
= &one_hundred
,
1275 .procname
= "stat_interval",
1276 .data
= &sysctl_stat_interval
,
1277 .maxlen
= sizeof(sysctl_stat_interval
),
1279 .proc_handler
= proc_dointvec_jiffies
,
1284 .procname
= "mmap_min_addr",
1285 .data
= &dac_mmap_min_addr
,
1286 .maxlen
= sizeof(unsigned long),
1288 .proc_handler
= mmap_min_addr_handler
,
1293 .procname
= "numa_zonelist_order",
1294 .data
= &numa_zonelist_order
,
1295 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1297 .proc_handler
= numa_zonelist_order_handler
,
1300 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1301 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1303 .procname
= "vdso_enabled",
1304 .data
= &vdso_enabled
,
1305 .maxlen
= sizeof(vdso_enabled
),
1307 .proc_handler
= proc_dointvec
,
1311 #ifdef CONFIG_HIGHMEM
1313 .procname
= "highmem_is_dirtyable",
1314 .data
= &vm_highmem_is_dirtyable
,
1315 .maxlen
= sizeof(vm_highmem_is_dirtyable
),
1317 .proc_handler
= proc_dointvec_minmax
,
1323 .procname
= "scan_unevictable_pages",
1324 .data
= &scan_unevictable_pages
,
1325 .maxlen
= sizeof(scan_unevictable_pages
),
1327 .proc_handler
= scan_unevictable_handler
,
1329 #ifdef CONFIG_MEMORY_FAILURE
1331 .procname
= "memory_failure_early_kill",
1332 .data
= &sysctl_memory_failure_early_kill
,
1333 .maxlen
= sizeof(sysctl_memory_failure_early_kill
),
1335 .proc_handler
= proc_dointvec_minmax
,
1340 .procname
= "memory_failure_recovery",
1341 .data
= &sysctl_memory_failure_recovery
,
1342 .maxlen
= sizeof(sysctl_memory_failure_recovery
),
1344 .proc_handler
= proc_dointvec_minmax
,
1352 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1353 static struct ctl_table binfmt_misc_table
[] = {
1358 static struct ctl_table fs_table
[] = {
1360 .procname
= "inode-nr",
1361 .data
= &inodes_stat
,
1362 .maxlen
= 2*sizeof(int),
1364 .proc_handler
= proc_nr_inodes
,
1367 .procname
= "inode-state",
1368 .data
= &inodes_stat
,
1369 .maxlen
= 7*sizeof(int),
1371 .proc_handler
= proc_nr_inodes
,
1374 .procname
= "file-nr",
1375 .data
= &files_stat
,
1376 .maxlen
= sizeof(files_stat
),
1378 .proc_handler
= proc_nr_files
,
1381 .procname
= "file-max",
1382 .data
= &files_stat
.max_files
,
1383 .maxlen
= sizeof(files_stat
.max_files
),
1385 .proc_handler
= proc_doulongvec_minmax
,
1388 .procname
= "nr_open",
1389 .data
= &sysctl_nr_open
,
1390 .maxlen
= sizeof(int),
1392 .proc_handler
= proc_dointvec_minmax
,
1393 .extra1
= &sysctl_nr_open_min
,
1394 .extra2
= &sysctl_nr_open_max
,
1397 .procname
= "dentry-state",
1398 .data
= &dentry_stat
,
1399 .maxlen
= 6*sizeof(int),
1401 .proc_handler
= proc_nr_dentry
,
1404 .procname
= "overflowuid",
1405 .data
= &fs_overflowuid
,
1406 .maxlen
= sizeof(int),
1408 .proc_handler
= proc_dointvec_minmax
,
1409 .extra1
= &minolduid
,
1410 .extra2
= &maxolduid
,
1413 .procname
= "overflowgid",
1414 .data
= &fs_overflowgid
,
1415 .maxlen
= sizeof(int),
1417 .proc_handler
= proc_dointvec_minmax
,
1418 .extra1
= &minolduid
,
1419 .extra2
= &maxolduid
,
1421 #ifdef CONFIG_FILE_LOCKING
1423 .procname
= "leases-enable",
1424 .data
= &leases_enable
,
1425 .maxlen
= sizeof(int),
1427 .proc_handler
= proc_dointvec
,
1430 #ifdef CONFIG_DNOTIFY
1432 .procname
= "dir-notify-enable",
1433 .data
= &dir_notify_enable
,
1434 .maxlen
= sizeof(int),
1436 .proc_handler
= proc_dointvec
,
1440 #ifdef CONFIG_FILE_LOCKING
1442 .procname
= "lease-break-time",
1443 .data
= &lease_break_time
,
1444 .maxlen
= sizeof(int),
1446 .proc_handler
= proc_dointvec
,
1451 .procname
= "aio-nr",
1453 .maxlen
= sizeof(aio_nr
),
1455 .proc_handler
= proc_doulongvec_minmax
,
1458 .procname
= "aio-max-nr",
1459 .data
= &aio_max_nr
,
1460 .maxlen
= sizeof(aio_max_nr
),
1462 .proc_handler
= proc_doulongvec_minmax
,
1464 #endif /* CONFIG_AIO */
1465 #ifdef CONFIG_INOTIFY_USER
1467 .procname
= "inotify",
1469 .child
= inotify_table
,
1474 .procname
= "epoll",
1476 .child
= epoll_table
,
1481 .procname
= "suid_dumpable",
1482 .data
= &suid_dumpable
,
1483 .maxlen
= sizeof(int),
1485 .proc_handler
= proc_dointvec_minmax
,
1489 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1491 .procname
= "binfmt_misc",
1493 .child
= binfmt_misc_table
,
1497 .procname
= "pipe-max-size",
1498 .data
= &pipe_max_size
,
1499 .maxlen
= sizeof(int),
1501 .proc_handler
= &pipe_proc_fn
,
1502 .extra1
= &pipe_min_size
,
1507 static struct ctl_table debug_table
[] = {
1508 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1509 defined(CONFIG_S390) || defined(CONFIG_TILE)
1511 .procname
= "exception-trace",
1512 .data
= &show_unhandled_signals
,
1513 .maxlen
= sizeof(int),
1515 .proc_handler
= proc_dointvec
1518 #if defined(CONFIG_OPTPROBES)
1520 .procname
= "kprobes-optimization",
1521 .data
= &sysctl_kprobes_optimization
,
1522 .maxlen
= sizeof(int),
1524 .proc_handler
= proc_kprobes_optimization_handler
,
1532 static struct ctl_table dev_table
[] = {
1536 static DEFINE_SPINLOCK(sysctl_lock
);
1538 /* called under sysctl_lock */
1539 static int use_table(struct ctl_table_header
*p
)
1541 if (unlikely(p
->unregistering
))
1547 /* called under sysctl_lock */
1548 static void unuse_table(struct ctl_table_header
*p
)
1551 if (unlikely(p
->unregistering
))
1552 complete(p
->unregistering
);
1555 /* called under sysctl_lock, will reacquire if has to wait */
1556 static void start_unregistering(struct ctl_table_header
*p
)
1559 * if p->used is 0, nobody will ever touch that entry again;
1560 * we'll eliminate all paths to it before dropping sysctl_lock
1562 if (unlikely(p
->used
)) {
1563 struct completion wait
;
1564 init_completion(&wait
);
1565 p
->unregistering
= &wait
;
1566 spin_unlock(&sysctl_lock
);
1567 wait_for_completion(&wait
);
1568 spin_lock(&sysctl_lock
);
1570 /* anything non-NULL; we'll never dereference it */
1571 p
->unregistering
= ERR_PTR(-EINVAL
);
1574 * do not remove from the list until nobody holds it; walking the
1575 * list in do_sysctl() relies on that.
1577 list_del_init(&p
->ctl_entry
);
1580 void sysctl_head_get(struct ctl_table_header
*head
)
1582 spin_lock(&sysctl_lock
);
1584 spin_unlock(&sysctl_lock
);
1587 static void free_head(struct rcu_head
*rcu
)
1589 kfree(container_of(rcu
, struct ctl_table_header
, rcu
));
1592 void sysctl_head_put(struct ctl_table_header
*head
)
1594 spin_lock(&sysctl_lock
);
1596 call_rcu(&head
->rcu
, free_head
);
1597 spin_unlock(&sysctl_lock
);
1600 struct ctl_table_header
*sysctl_head_grab(struct ctl_table_header
*head
)
1604 spin_lock(&sysctl_lock
);
1605 if (!use_table(head
))
1606 head
= ERR_PTR(-ENOENT
);
1607 spin_unlock(&sysctl_lock
);
1611 void sysctl_head_finish(struct ctl_table_header
*head
)
1615 spin_lock(&sysctl_lock
);
1617 spin_unlock(&sysctl_lock
);
1620 static struct ctl_table_set
*
1621 lookup_header_set(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1623 struct ctl_table_set
*set
= &root
->default_set
;
1625 set
= root
->lookup(root
, namespaces
);
1629 static struct list_head
*
1630 lookup_header_list(struct ctl_table_root
*root
, struct nsproxy
*namespaces
)
1632 struct ctl_table_set
*set
= lookup_header_set(root
, namespaces
);
1636 struct ctl_table_header
*__sysctl_head_next(struct nsproxy
*namespaces
,
1637 struct ctl_table_header
*prev
)
1639 struct ctl_table_root
*root
;
1640 struct list_head
*header_list
;
1641 struct ctl_table_header
*head
;
1642 struct list_head
*tmp
;
1644 spin_lock(&sysctl_lock
);
1647 tmp
= &prev
->ctl_entry
;
1651 tmp
= &root_table_header
.ctl_entry
;
1653 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1655 if (!use_table(head
))
1657 spin_unlock(&sysctl_lock
);
1662 header_list
= lookup_header_list(root
, namespaces
);
1663 if (tmp
!= header_list
)
1667 root
= list_entry(root
->root_list
.next
,
1668 struct ctl_table_root
, root_list
);
1669 if (root
== &sysctl_table_root
)
1671 header_list
= lookup_header_list(root
, namespaces
);
1672 } while (list_empty(header_list
));
1673 tmp
= header_list
->next
;
1676 spin_unlock(&sysctl_lock
);
1680 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1682 return __sysctl_head_next(current
->nsproxy
, prev
);
1685 void register_sysctl_root(struct ctl_table_root
*root
)
1687 spin_lock(&sysctl_lock
);
1688 list_add_tail(&root
->root_list
, &sysctl_table_root
.root_list
);
1689 spin_unlock(&sysctl_lock
);
1693 * sysctl_perm does NOT grant the superuser all rights automatically, because
1694 * some sysctl variables are readonly even to root.
1697 static int test_perm(int mode
, int op
)
1699 if (!current_euid())
1701 else if (in_egroup_p(0))
1703 if ((op
& ~mode
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
)) == 0)
1708 int sysctl_perm(struct ctl_table_root
*root
, struct ctl_table
*table
, int op
)
1712 if (root
->permissions
)
1713 mode
= root
->permissions(root
, current
->nsproxy
, table
);
1717 return test_perm(mode
, op
);
1720 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1722 for (; table
->procname
; table
++) {
1723 table
->parent
= parent
;
1725 sysctl_set_parent(table
, table
->child
);
1729 static __init
int sysctl_init(void)
1731 sysctl_set_parent(NULL
, root_table
);
1732 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1733 sysctl_check_table(current
->nsproxy
, root_table
);
1738 core_initcall(sysctl_init
);
1740 static struct ctl_table
*is_branch_in(struct ctl_table
*branch
,
1741 struct ctl_table
*table
)
1743 struct ctl_table
*p
;
1744 const char *s
= branch
->procname
;
1746 /* branch should have named subdirectory as its first element */
1747 if (!s
|| !branch
->child
)
1750 /* ... and nothing else */
1751 if (branch
[1].procname
)
1754 /* table should contain subdirectory with the same name */
1755 for (p
= table
; p
->procname
; p
++) {
1758 if (p
->procname
&& strcmp(p
->procname
, s
) == 0)
1764 /* see if attaching q to p would be an improvement */
1765 static void try_attach(struct ctl_table_header
*p
, struct ctl_table_header
*q
)
1767 struct ctl_table
*to
= p
->ctl_table
, *by
= q
->ctl_table
;
1768 struct ctl_table
*next
;
1770 int not_in_parent
= !p
->attached_by
;
1772 while ((next
= is_branch_in(by
, to
)) != NULL
) {
1773 if (by
== q
->attached_by
)
1775 if (to
== p
->attached_by
)
1781 if (is_better
&& not_in_parent
) {
1782 q
->attached_by
= by
;
1783 q
->attached_to
= to
;
1789 * __register_sysctl_paths - register a sysctl hierarchy
1790 * @root: List of sysctl headers to register on
1791 * @namespaces: Data to compute which lists of sysctl entries are visible
1792 * @path: The path to the directory the sysctl table is in.
1793 * @table: the top-level table structure
1795 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1796 * array. A completely 0 filled entry terminates the table.
1798 * The members of the &struct ctl_table structure are used as follows:
1800 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1801 * enter a sysctl file
1803 * data - a pointer to data for use by proc_handler
1805 * maxlen - the maximum size in bytes of the data
1807 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1809 * child - a pointer to the child sysctl table if this entry is a directory, or
1812 * proc_handler - the text handler routine (described below)
1814 * de - for internal use by the sysctl routines
1816 * extra1, extra2 - extra pointers usable by the proc handler routines
1818 * Leaf nodes in the sysctl tree will be represented by a single file
1819 * under /proc; non-leaf nodes will be represented by directories.
1821 * sysctl(2) can automatically manage read and write requests through
1822 * the sysctl table. The data and maxlen fields of the ctl_table
1823 * struct enable minimal validation of the values being written to be
1824 * performed, and the mode field allows minimal authentication.
1826 * There must be a proc_handler routine for any terminal nodes
1827 * mirrored under /proc/sys (non-terminals are handled by a built-in
1828 * directory handler). Several default handlers are available to
1829 * cover common cases -
1831 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1832 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1833 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1835 * It is the handler's job to read the input buffer from user memory
1836 * and process it. The handler should return 0 on success.
1838 * This routine returns %NULL on a failure to register, and a pointer
1839 * to the table header on success.
1841 struct ctl_table_header
*__register_sysctl_paths(
1842 struct ctl_table_root
*root
,
1843 struct nsproxy
*namespaces
,
1844 const struct ctl_path
*path
, struct ctl_table
*table
)
1846 struct ctl_table_header
*header
;
1847 struct ctl_table
*new, **prevp
;
1848 unsigned int n
, npath
;
1849 struct ctl_table_set
*set
;
1851 /* Count the path components */
1852 for (npath
= 0; path
[npath
].procname
; ++npath
)
1856 * For each path component, allocate a 2-element ctl_table array.
1857 * The first array element will be filled with the sysctl entry
1858 * for this, the second will be the sentinel (procname == 0).
1860 * We allocate everything in one go so that we don't have to
1861 * worry about freeing additional memory in unregister_sysctl_table.
1863 header
= kzalloc(sizeof(struct ctl_table_header
) +
1864 (2 * npath
* sizeof(struct ctl_table
)), GFP_KERNEL
);
1868 new = (struct ctl_table
*) (header
+ 1);
1870 /* Now connect the dots */
1871 prevp
= &header
->ctl_table
;
1872 for (n
= 0; n
< npath
; ++n
, ++path
) {
1873 /* Copy the procname */
1874 new->procname
= path
->procname
;
1878 prevp
= &new->child
;
1883 header
->ctl_table_arg
= table
;
1885 INIT_LIST_HEAD(&header
->ctl_entry
);
1887 header
->unregistering
= NULL
;
1888 header
->root
= root
;
1889 sysctl_set_parent(NULL
, header
->ctl_table
);
1891 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1892 if (sysctl_check_table(namespaces
, header
->ctl_table
)) {
1897 spin_lock(&sysctl_lock
);
1898 header
->set
= lookup_header_set(root
, namespaces
);
1899 header
->attached_by
= header
->ctl_table
;
1900 header
->attached_to
= root_table
;
1901 header
->parent
= &root_table_header
;
1902 for (set
= header
->set
; set
; set
= set
->parent
) {
1903 struct ctl_table_header
*p
;
1904 list_for_each_entry(p
, &set
->list
, ctl_entry
) {
1905 if (p
->unregistering
)
1907 try_attach(p
, header
);
1910 header
->parent
->count
++;
1911 list_add_tail(&header
->ctl_entry
, &header
->set
->list
);
1912 spin_unlock(&sysctl_lock
);
1918 * register_sysctl_table_path - register a sysctl table hierarchy
1919 * @path: The path to the directory the sysctl table is in.
1920 * @table: the top-level table structure
1922 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1923 * array. A completely 0 filled entry terminates the table.
1925 * See __register_sysctl_paths for more details.
1927 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
1928 struct ctl_table
*table
)
1930 return __register_sysctl_paths(&sysctl_table_root
, current
->nsproxy
,
1935 * register_sysctl_table - register a sysctl table hierarchy
1936 * @table: the top-level table structure
1938 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1939 * array. A completely 0 filled entry terminates the table.
1941 * See register_sysctl_paths for more details.
1943 struct ctl_table_header
*register_sysctl_table(struct ctl_table
*table
)
1945 static const struct ctl_path null_path
[] = { {} };
1947 return register_sysctl_paths(null_path
, table
);
1951 * unregister_sysctl_table - unregister a sysctl table hierarchy
1952 * @header: the header returned from register_sysctl_table
1954 * Unregisters the sysctl table and all children. proc entries may not
1955 * actually be removed until they are no longer used by anyone.
1957 void unregister_sysctl_table(struct ctl_table_header
* header
)
1964 spin_lock(&sysctl_lock
);
1965 start_unregistering(header
);
1966 if (!--header
->parent
->count
) {
1968 call_rcu(&header
->parent
->rcu
, free_head
);
1970 if (!--header
->count
)
1971 call_rcu(&header
->rcu
, free_head
);
1972 spin_unlock(&sysctl_lock
);
1975 int sysctl_is_seen(struct ctl_table_header
*p
)
1977 struct ctl_table_set
*set
= p
->set
;
1979 spin_lock(&sysctl_lock
);
1980 if (p
->unregistering
)
1982 else if (!set
->is_seen
)
1985 res
= set
->is_seen(set
);
1986 spin_unlock(&sysctl_lock
);
1990 void setup_sysctl_set(struct ctl_table_set
*p
,
1991 struct ctl_table_set
*parent
,
1992 int (*is_seen
)(struct ctl_table_set
*))
1994 INIT_LIST_HEAD(&p
->list
);
1995 p
->parent
= parent
? parent
: &sysctl_table_root
.default_set
;
1996 p
->is_seen
= is_seen
;
1999 #else /* !CONFIG_SYSCTL */
2000 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
2005 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
2006 struct ctl_table
*table
)
2011 void unregister_sysctl_table(struct ctl_table_header
* table
)
2015 void setup_sysctl_set(struct ctl_table_set
*p
,
2016 struct ctl_table_set
*parent
,
2017 int (*is_seen
)(struct ctl_table_set
*))
2021 void sysctl_head_put(struct ctl_table_header
*head
)
2025 #endif /* CONFIG_SYSCTL */
2031 #ifdef CONFIG_PROC_SYSCTL
2033 static int _proc_do_string(void* data
, int maxlen
, int write
,
2034 void __user
*buffer
,
2035 size_t *lenp
, loff_t
*ppos
)
2041 if (!data
|| !maxlen
|| !*lenp
) {
2049 while (len
< *lenp
) {
2050 if (get_user(c
, p
++))
2052 if (c
== 0 || c
== '\n')
2058 if(copy_from_user(data
, buffer
, len
))
2060 ((char *) data
)[len
] = 0;
2078 if(copy_to_user(buffer
, data
, len
))
2081 if(put_user('\n', ((char __user
*) buffer
) + len
))
2092 * proc_dostring - read a string sysctl
2093 * @table: the sysctl table
2094 * @write: %TRUE if this is a write to the sysctl file
2095 * @buffer: the user buffer
2096 * @lenp: the size of the user buffer
2097 * @ppos: file position
2099 * Reads/writes a string from/to the user buffer. If the kernel
2100 * buffer provided is not large enough to hold the string, the
2101 * string is truncated. The copied string is %NULL-terminated.
2102 * If the string is being read by the user process, it is copied
2103 * and a newline '\n' is added. It is truncated if the buffer is
2106 * Returns 0 on success.
2108 int proc_dostring(struct ctl_table
*table
, int write
,
2109 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2111 return _proc_do_string(table
->data
, table
->maxlen
, write
,
2112 buffer
, lenp
, ppos
);
2115 static size_t proc_skip_spaces(char **buf
)
2118 char *tmp
= skip_spaces(*buf
);
2124 static void proc_skip_char(char **buf
, size_t *size
, const char v
)
2134 #define TMPBUFLEN 22
2136 * proc_get_long - reads an ASCII formatted integer from a user buffer
2138 * @buf: a kernel buffer
2139 * @size: size of the kernel buffer
2140 * @val: this is where the number will be stored
2141 * @neg: set to %TRUE if number is negative
2142 * @perm_tr: a vector which contains the allowed trailers
2143 * @perm_tr_len: size of the perm_tr vector
2144 * @tr: pointer to store the trailer character
2146 * In case of success %0 is returned and @buf and @size are updated with
2147 * the amount of bytes read. If @tr is non-NULL and a trailing
2148 * character exists (size is non-zero after returning from this
2149 * function), @tr is updated with the trailing character.
2151 static int proc_get_long(char **buf
, size_t *size
,
2152 unsigned long *val
, bool *neg
,
2153 const char *perm_tr
, unsigned perm_tr_len
, char *tr
)
2156 char *p
, tmp
[TMPBUFLEN
];
2162 if (len
> TMPBUFLEN
- 1)
2163 len
= TMPBUFLEN
- 1;
2165 memcpy(tmp
, *buf
, len
);
2169 if (*p
== '-' && *size
> 1) {
2177 *val
= simple_strtoul(p
, &p
, 0);
2181 /* We don't know if the next char is whitespace thus we may accept
2182 * invalid integers (e.g. 1234...a) or two integers instead of one
2183 * (e.g. 123...1). So lets not allow such large numbers. */
2184 if (len
== TMPBUFLEN
- 1)
2187 if (len
< *size
&& perm_tr_len
&& !memchr(perm_tr
, *p
, perm_tr_len
))
2190 if (tr
&& (len
< *size
))
2200 * proc_put_long - converts an integer to a decimal ASCII formatted string
2202 * @buf: the user buffer
2203 * @size: the size of the user buffer
2204 * @val: the integer to be converted
2205 * @neg: sign of the number, %TRUE for negative
2207 * In case of success %0 is returned and @buf and @size are updated with
2208 * the amount of bytes written.
2210 static int proc_put_long(void __user
**buf
, size_t *size
, unsigned long val
,
2214 char tmp
[TMPBUFLEN
], *p
= tmp
;
2216 sprintf(p
, "%s%lu", neg
? "-" : "", val
);
2220 if (copy_to_user(*buf
, tmp
, len
))
2228 static int proc_put_char(void __user
**buf
, size_t *size
, char c
)
2231 char __user
**buffer
= (char __user
**)buf
;
2232 if (put_user(c
, *buffer
))
2234 (*size
)--, (*buffer
)++;
2240 static int do_proc_dointvec_conv(bool *negp
, unsigned long *lvalp
,
2242 int write
, void *data
)
2245 *valp
= *negp
? -*lvalp
: *lvalp
;
2250 *lvalp
= (unsigned long)-val
;
2253 *lvalp
= (unsigned long)val
;
2259 static const char proc_wspace_sep
[] = { ' ', '\t', '\n' };
2261 static int __do_proc_dointvec(void *tbl_data
, struct ctl_table
*table
,
2262 int write
, void __user
*buffer
,
2263 size_t *lenp
, loff_t
*ppos
,
2264 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2265 int write
, void *data
),
2268 int *i
, vleft
, first
= 1, err
= 0;
2269 unsigned long page
= 0;
2273 if (!tbl_data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2278 i
= (int *) tbl_data
;
2279 vleft
= table
->maxlen
/ sizeof(*i
);
2283 conv
= do_proc_dointvec_conv
;
2286 if (left
> PAGE_SIZE
- 1)
2287 left
= PAGE_SIZE
- 1;
2288 page
= __get_free_page(GFP_TEMPORARY
);
2289 kbuf
= (char *) page
;
2292 if (copy_from_user(kbuf
, buffer
, left
)) {
2299 for (; left
&& vleft
--; i
++, first
=0) {
2304 left
-= proc_skip_spaces(&kbuf
);
2308 err
= proc_get_long(&kbuf
, &left
, &lval
, &neg
,
2310 sizeof(proc_wspace_sep
), NULL
);
2313 if (conv(&neg
, &lval
, i
, 1, data
)) {
2318 if (conv(&neg
, &lval
, i
, 0, data
)) {
2323 err
= proc_put_char(&buffer
, &left
, '\t');
2326 err
= proc_put_long(&buffer
, &left
, lval
, neg
);
2332 if (!write
&& !first
&& left
&& !err
)
2333 err
= proc_put_char(&buffer
, &left
, '\n');
2334 if (write
&& !err
&& left
)
2335 left
-= proc_skip_spaces(&kbuf
);
2340 return err
? : -EINVAL
;
2347 static int do_proc_dointvec(struct ctl_table
*table
, int write
,
2348 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
2349 int (*conv
)(bool *negp
, unsigned long *lvalp
, int *valp
,
2350 int write
, void *data
),
2353 return __do_proc_dointvec(table
->data
, table
, write
,
2354 buffer
, lenp
, ppos
, conv
, data
);
2358 * proc_dointvec - read a vector of integers
2359 * @table: the sysctl table
2360 * @write: %TRUE if this is a write to the sysctl file
2361 * @buffer: the user buffer
2362 * @lenp: the size of the user buffer
2363 * @ppos: file position
2365 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2366 * values from/to the user buffer, treated as an ASCII string.
2368 * Returns 0 on success.
2370 int proc_dointvec(struct ctl_table
*table
, int write
,
2371 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2373 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2378 * Taint values can only be increased
2379 * This means we can safely use a temporary.
2381 static int proc_taint(struct ctl_table
*table
, int write
,
2382 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2385 unsigned long tmptaint
= get_taint();
2388 if (write
&& !capable(CAP_SYS_ADMIN
))
2393 err
= proc_doulongvec_minmax(&t
, write
, buffer
, lenp
, ppos
);
2399 * Poor man's atomic or. Not worth adding a primitive
2400 * to everyone's atomic.h for this
2403 for (i
= 0; i
< BITS_PER_LONG
&& tmptaint
>> i
; i
++) {
2404 if ((tmptaint
>> i
) & 1)
2412 #ifdef CONFIG_PRINTK
2413 static int proc_dmesg_restrict(struct ctl_table
*table
, int write
,
2414 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2416 if (write
&& !capable(CAP_SYS_ADMIN
))
2419 return proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
2423 struct do_proc_dointvec_minmax_conv_param
{
2428 static int do_proc_dointvec_minmax_conv(bool *negp
, unsigned long *lvalp
,
2430 int write
, void *data
)
2432 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
2434 int val
= *negp
? -*lvalp
: *lvalp
;
2435 if ((param
->min
&& *param
->min
> val
) ||
2436 (param
->max
&& *param
->max
< val
))
2443 *lvalp
= (unsigned long)-val
;
2446 *lvalp
= (unsigned long)val
;
2453 * proc_dointvec_minmax - read a vector of integers with min/max values
2454 * @table: the sysctl table
2455 * @write: %TRUE if this is a write to the sysctl file
2456 * @buffer: the user buffer
2457 * @lenp: the size of the user buffer
2458 * @ppos: file position
2460 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2461 * values from/to the user buffer, treated as an ASCII string.
2463 * This routine will ensure the values are within the range specified by
2464 * table->extra1 (min) and table->extra2 (max).
2466 * Returns 0 on success.
2468 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2469 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2471 struct do_proc_dointvec_minmax_conv_param param
= {
2472 .min
= (int *) table
->extra1
,
2473 .max
= (int *) table
->extra2
,
2475 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2476 do_proc_dointvec_minmax_conv
, ¶m
);
2479 static int __do_proc_doulongvec_minmax(void *data
, struct ctl_table
*table
, int write
,
2480 void __user
*buffer
,
2481 size_t *lenp
, loff_t
*ppos
,
2482 unsigned long convmul
,
2483 unsigned long convdiv
)
2485 unsigned long *i
, *min
, *max
;
2486 int vleft
, first
= 1, err
= 0;
2487 unsigned long page
= 0;
2491 if (!data
|| !table
->maxlen
|| !*lenp
|| (*ppos
&& !write
)) {
2496 i
= (unsigned long *) data
;
2497 min
= (unsigned long *) table
->extra1
;
2498 max
= (unsigned long *) table
->extra2
;
2499 vleft
= table
->maxlen
/ sizeof(unsigned long);
2503 if (left
> PAGE_SIZE
- 1)
2504 left
= PAGE_SIZE
- 1;
2505 page
= __get_free_page(GFP_TEMPORARY
);
2506 kbuf
= (char *) page
;
2509 if (copy_from_user(kbuf
, buffer
, left
)) {
2516 for (; left
&& vleft
--; i
++, first
= 0) {
2522 left
-= proc_skip_spaces(&kbuf
);
2524 err
= proc_get_long(&kbuf
, &left
, &val
, &neg
,
2526 sizeof(proc_wspace_sep
), NULL
);
2531 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2535 val
= convdiv
* (*i
) / convmul
;
2537 err
= proc_put_char(&buffer
, &left
, '\t');
2538 err
= proc_put_long(&buffer
, &left
, val
, false);
2544 if (!write
&& !first
&& left
&& !err
)
2545 err
= proc_put_char(&buffer
, &left
, '\n');
2547 left
-= proc_skip_spaces(&kbuf
);
2552 return err
? : -EINVAL
;
2559 static int do_proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2560 void __user
*buffer
,
2561 size_t *lenp
, loff_t
*ppos
,
2562 unsigned long convmul
,
2563 unsigned long convdiv
)
2565 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2566 buffer
, lenp
, ppos
, convmul
, convdiv
);
2570 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2571 * @table: the sysctl table
2572 * @write: %TRUE if this is a write to the sysctl file
2573 * @buffer: the user buffer
2574 * @lenp: the size of the user buffer
2575 * @ppos: file position
2577 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2578 * values from/to the user buffer, treated as an ASCII string.
2580 * This routine will ensure the values are within the range specified by
2581 * table->extra1 (min) and table->extra2 (max).
2583 * Returns 0 on success.
2585 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2586 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2588 return do_proc_doulongvec_minmax(table
, write
, buffer
, lenp
, ppos
, 1l, 1l);
2592 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values 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. The values
2601 * are treated as milliseconds, and converted to jiffies when they are stored.
2603 * This routine will ensure the values are within the range specified by
2604 * table->extra1 (min) and table->extra2 (max).
2606 * Returns 0 on success.
2608 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2609 void __user
*buffer
,
2610 size_t *lenp
, loff_t
*ppos
)
2612 return do_proc_doulongvec_minmax(table
, write
, buffer
,
2613 lenp
, ppos
, HZ
, 1000l);
2617 static int do_proc_dointvec_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2619 int write
, void *data
)
2622 if (*lvalp
> LONG_MAX
/ HZ
)
2624 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2630 lval
= (unsigned long)-val
;
2633 lval
= (unsigned long)val
;
2640 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2642 int write
, void *data
)
2645 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2647 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2653 lval
= (unsigned long)-val
;
2656 lval
= (unsigned long)val
;
2658 *lvalp
= jiffies_to_clock_t(lval
);
2663 static int do_proc_dointvec_ms_jiffies_conv(bool *negp
, unsigned long *lvalp
,
2665 int write
, void *data
)
2668 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2674 lval
= (unsigned long)-val
;
2677 lval
= (unsigned long)val
;
2679 *lvalp
= jiffies_to_msecs(lval
);
2685 * proc_dointvec_jiffies - read a vector of integers as seconds
2686 * @table: the sysctl table
2687 * @write: %TRUE if this is a write to the sysctl file
2688 * @buffer: the user buffer
2689 * @lenp: the size of the user buffer
2690 * @ppos: file position
2692 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2693 * values from/to the user buffer, treated as an ASCII string.
2694 * The values read are assumed to be in seconds, and are converted into
2697 * Returns 0 on success.
2699 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2700 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2702 return do_proc_dointvec(table
,write
,buffer
,lenp
,ppos
,
2703 do_proc_dointvec_jiffies_conv
,NULL
);
2707 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ 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: pointer to the 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 1/USER_HZ seconds, and
2717 * are converted into jiffies.
2719 * Returns 0 on success.
2721 int proc_dointvec_userhz_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_userhz_jiffies_conv
,NULL
);
2729 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
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: file position
2735 * @ppos: the current position in the file
2737 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2738 * values from/to the user buffer, treated as an ASCII string.
2739 * The values read are assumed to be in 1/1000 seconds, and
2740 * are converted into jiffies.
2742 * Returns 0 on success.
2744 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2745 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2747 return do_proc_dointvec(table
, write
, buffer
, lenp
, ppos
,
2748 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2751 static int proc_do_cad_pid(struct ctl_table
*table
, int write
,
2752 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2754 struct pid
*new_pid
;
2758 tmp
= pid_vnr(cad_pid
);
2760 r
= __do_proc_dointvec(&tmp
, table
, write
, buffer
,
2761 lenp
, ppos
, NULL
, NULL
);
2765 new_pid
= find_get_pid(tmp
);
2769 put_pid(xchg(&cad_pid
, new_pid
));
2774 * proc_do_large_bitmap - read/write from/to a large bitmap
2775 * @table: the sysctl table
2776 * @write: %TRUE if this is a write to the sysctl file
2777 * @buffer: the user buffer
2778 * @lenp: the size of the user buffer
2779 * @ppos: file position
2781 * The bitmap is stored at table->data and the bitmap length (in bits)
2784 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2785 * large bitmaps may be represented in a compact manner. Writing into
2786 * the file will clear the bitmap then update it with the given input.
2788 * Returns 0 on success.
2790 int proc_do_large_bitmap(struct ctl_table
*table
, int write
,
2791 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2795 size_t left
= *lenp
;
2796 unsigned long bitmap_len
= table
->maxlen
;
2797 unsigned long *bitmap
= (unsigned long *) table
->data
;
2798 unsigned long *tmp_bitmap
= NULL
;
2799 char tr_a
[] = { '-', ',', '\n' }, tr_b
[] = { ',', '\n', 0 }, c
;
2801 if (!bitmap_len
|| !left
|| (*ppos
&& !write
)) {
2807 unsigned long page
= 0;
2810 if (left
> PAGE_SIZE
- 1)
2811 left
= PAGE_SIZE
- 1;
2813 page
= __get_free_page(GFP_TEMPORARY
);
2814 kbuf
= (char *) page
;
2817 if (copy_from_user(kbuf
, buffer
, left
)) {
2823 tmp_bitmap
= kzalloc(BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long),
2829 proc_skip_char(&kbuf
, &left
, '\n');
2830 while (!err
&& left
) {
2831 unsigned long val_a
, val_b
;
2834 err
= proc_get_long(&kbuf
, &left
, &val_a
, &neg
, tr_a
,
2838 if (val_a
>= bitmap_len
|| neg
) {
2850 err
= proc_get_long(&kbuf
, &left
, &val_b
,
2851 &neg
, tr_b
, sizeof(tr_b
),
2855 if (val_b
>= bitmap_len
|| neg
||
2866 while (val_a
<= val_b
)
2867 set_bit(val_a
++, tmp_bitmap
);
2870 proc_skip_char(&kbuf
, &left
, '\n');
2874 unsigned long bit_a
, bit_b
= 0;
2877 bit_a
= find_next_bit(bitmap
, bitmap_len
, bit_b
);
2878 if (bit_a
>= bitmap_len
)
2880 bit_b
= find_next_zero_bit(bitmap
, bitmap_len
,
2884 err
= proc_put_char(&buffer
, &left
, ',');
2888 err
= proc_put_long(&buffer
, &left
, bit_a
, false);
2891 if (bit_a
!= bit_b
) {
2892 err
= proc_put_char(&buffer
, &left
, '-');
2895 err
= proc_put_long(&buffer
, &left
, bit_b
, false);
2903 err
= proc_put_char(&buffer
, &left
, '\n');
2909 bitmap_or(bitmap
, bitmap
, tmp_bitmap
, bitmap_len
);
2911 memcpy(bitmap
, tmp_bitmap
,
2912 BITS_TO_LONGS(bitmap_len
) * sizeof(unsigned long));
2924 #else /* CONFIG_PROC_SYSCTL */
2926 int proc_dostring(struct ctl_table
*table
, int write
,
2927 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2932 int proc_dointvec(struct ctl_table
*table
, int write
,
2933 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2938 int proc_dointvec_minmax(struct ctl_table
*table
, int write
,
2939 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2944 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
,
2945 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2950 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
,
2951 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2956 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
,
2957 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2962 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2963 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2968 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2969 void __user
*buffer
,
2970 size_t *lenp
, loff_t
*ppos
)
2976 #endif /* CONFIG_PROC_SYSCTL */
2979 * No sense putting this after each symbol definition, twice,
2980 * exception granted :-)
2982 EXPORT_SYMBOL(proc_dointvec
);
2983 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2984 EXPORT_SYMBOL(proc_dointvec_minmax
);
2985 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2986 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2987 EXPORT_SYMBOL(proc_dostring
);
2988 EXPORT_SYMBOL(proc_doulongvec_minmax
);
2989 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
2990 EXPORT_SYMBOL(register_sysctl_table
);
2991 EXPORT_SYMBOL(register_sysctl_paths
);
2992 EXPORT_SYMBOL(unregister_sysctl_table
);